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TUGAS AKHIR

STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME

SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN

IMPAK KOMPOSIT BERPENGUAT SERAT RAMI

BERMATRIK POLYESTER BQTN 157

Disusun:

LUDI HARTANTO

NIM : D 200 020 185

JURUSAN TEKNIK MESIN FAKULTAS TEKNIK

UNIVERSITAS MUHAMMADIYAH SURAKARTA

JULI 2009

ii

PERNYATAAN KEASLIAN SKRIPSI

Saya menyatakan dengan sesungguhnya bahwa skripsi dengan judul :

“STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT

TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT

BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157”

Yang dibuat untuk memenuhi sebagai syarat memperoleh derajat sarjana

S1 pada Jurusan Teknik Mesin Fakultas Teknik Universitas

Muhammadiyah Surakarta, sejauh yang saya ketahui bukan merupakan

tiruan atau duplikasi dari skripsi yang sudah dipublikasikan dan pernah

dipakai untuk mendapatkan gelar kesarjanaan di lingkungan Universitas

Muhammadiyah Surakarta atau instansi manapun, kecuali bagian yang

sumber informasinya saya cantumkan sebagaimana mestinya.

Surakarta, 7 Juli 2009 Yang menyatakan,

Ludi Hartanto

iii

HALAMAN PERSETUJUAN

Tugas Akhir berjudul “STUDY PERLAKUAN ALKALI DAN FRAKSI

VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN

IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK

POLYESTER BQTN 157”, telah disetujui oleh Pembimbing dan diterima

untuk memenuhi sebagai persyaratan memperoleh gelar sarjana S1 pada

Jurusan Teknik Mesin Fakultas Teknik Universitas Muhammadiyah

Surakarta.

Dipersiapkan oleh :

Nama : LUDI HARTANTO

NIM : D200 020 185

Disetujui pada

Hari :............................

Tanggal :............................

Pembimbing Utama

Ir. Agus Hariyanto, MT

Pembimbing Pendamping

Agus Yulianto, ST,MT

iv

HALAMAN PENGESAHAN

Tugas Akhir berjudul : “STUDY PERLAKUAN ALKALI DAN FRAKSI

VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN

IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK

POLYESTER BQTN 157”. telah dipertahankan di hadapan Tim Penguji

dan telah dinyatakan sah untuk memenuhi sebagai syarat memperoleh

derajat sarjana S1 pada Jurusan Teknik Mesin Fakultas Teknik

Universitas Muhammadiyah Surakarta.

Dipersiapkan oleh :

Nama : LUDI HARTANTO NIM : D200 020 185

Disahkan pada : Hari :......................... Tanggal :…......................

Tim Penguji : Ketua : Ir. Agus Hariyanto, MT …………………. Anggota 1 : Agus Yulianto, ST, MT .......................... Anggota 2 : Dr.Kuncoro Diharjo, ST,MT ..........................

Dekan,

Ir. H Sri Widodo, MT

Ketua Jurusan,

Marwan Effendy, ST., MT

vi

MOTTO

”Jadikanlah sabaar dan shalat sebagai penolongmu.

Dan sesungguhnya yang demikian itu sungguh berat,

kecuali bagi orang-orang yang khusyu”

(Q.S Al Baqarah : 45)

”karena sesungguhnya sesudah kesulitan itu ada kemudahan,

maka apabila kamu telah selesai dari sesuatu urusan, kerjakanlah

dengan sungguh-sungguh urusan yang lain.

Dan hanya kepada Tuhanmulah hendaknya kamu berharap”

(Q.S Alam Nasyarah : 6-8)

”Yang paling banyak menjatuhkan orang, itu adalah tidak

seimbangnyaantara perkataan dan perbuatan”

(Abdullah Gymnastiar)

”Hidup adalah belajar, kehidupan adalah pelajaran.

Mati adalah misteri, penentuan dan akherat adalah prestasi hidup.

Maka janganlah kamu hidup dengan mimpi-mimpi, tapi hidupkanlah

mimpi-mimpimu”

(Abdullah Gymnastiar)

”Tak ada pengorbanan maka tak ada kemenangan dan tak ada usaha

maka tak akan ada keberhasilan”

(Penulis)

vii

PERSEMBAHAN

Sujud syukurku pada-Mu Illahi Robbi yang senantiasa memberikan

kemudahan bagi hamba-Nya yang mau berusaha. Petunjuk dan

bimbingan-Mu selama hamba menuntut ilmu diperantauan berbuah karya

sederhana ini yang kupersembahkan kepada :

Agamaku yang telah mengenalkan aku kepada ALLAH SWT serta

Rosul-Nya danmengarahkan jalan dari gelap-gulita menuju terang

benderang, terimakasih ALLAH atas ridhonya hingga saya dapat

menyelesaikan tugas akhir ini, walaupun kadang keluar dari jalan

yang Engkau tetapkan.

(“Engkau yang mendengar do’aku dan mengabulkan jerih payahku”).

Ayah dan Ibu tercinta, dengan do’a dan kasih sayang tulusnya selalu

senantiasa memberikan kekuatan dalam setiap langkah ananda,

terima kasih atas semua pengorbanan yang tidak ternilai harganya.

Saudara-saudaraku yang selalu memberikanku do’a, inpirasi maupun

dukungan kepadaku.

Seseorang yang kelak kan menjadi pendampingku, yang telah

memberikanku inspirasi, motivasi, dan kesetiaan.

Almamater Fakultas Teknik UMS.

viii

ABSTRAKSI

STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT

TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT

BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157

Ludi Hartanto., Agus Hariyanto, Agus Yulianto.

Teknik Mesin Universitas Muhammadiyah Surakarta JL. A. Yani Pabelan Kartasura Tromol Pos I Sukoharjo

ABSTRAKSI

Tujuan dari penelitian ini adalah untuk mengetahui kekuatan bending,tarik dan impak yang optimal dari komposit serat rami pada fraksi volume 20%, 30%, 40%, 50% dengan variasi ketebalan 1mm hingga 5mm,dengan perlakuan alkali serta mengetahui jenis patahan dengan pengamatan makro pada specimen yang memiliki harga optimal dari pengujian bending,tarik dan impak.

Pada penelitian ini bahan yang dipergunakan adalah serat ramie yang disusunan acak dengan fraksi volume 20%, 30%, 40%, 50%, dengan variasi tebal 1mm hingga 5mm, menggunakan Polyester BQTN 157 sebagai matriknya. Pembuatan dengan cara press mold, pengujian bending yang dilakukan dengan acuan standar ASTM D 790-02,tarik dengan standart ASTM 638-02 dan Impak charpy dengan acuan standart ASTM D 256-00.

Hasil pengujian didapat pengaruh alkali 2,4,6,dan 8 jam pada fraksi volume 20%, 30%, 40%, 50%, dengan variasi tebal 1mm hingga 5mm. Pada pengujian bending optimal rata-rata pada vf 40% dengan ketebalan 3mm dan paling optimal pada alkali 2 jam,Pada uji tarik optimal pada vf 50% ketebalan 5mm dan paling optimal pada alkali 2 jam,dan Pada uji Impak optimal rata-rata pada vf 40% dan 50% pada ketebalan 5mm dan paling optimal pada vf 50% alkali 6 jam. Pengamatan struktur makro didapatkan jenis patahan broken fiber. Kata kunci : Serat Rami, Polyester, Kekuatan, Alkali.

ix

KATA PENGANTAR

Assalamu’alaikum Wr. Wb.

Syukur Alhamdulillah, penulis panjatkan kehadirat Allah SWT atas

berkah dan rahmat-Nya sehingga penyusun laporan penelitian ini dapat

terselesaikan.

Tugas Akhir berjudul ”STUDY PERLAKUAN ALKALI DAN

FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK,

DAN IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK

POLYESTER BQTN 157”, dapat terselesaikan atas dukungan dari pihak.

Untuk itu pada kesempatan ini, penulis dengan segala ketulusan dan

keikhlasan hati ingin menyampaikan rasa terima kasih dan penghargaan

yang sebesar-besarnya kepada :

1. Bapak Ir. H. Sri Widodo, MT, selaku Dekan Fakultas Teknik Universitas

Muhammadiyah Surakarta.

2. Bapak Marwan Effendy, ST, MT, selaku Ketua Jurusan Teknik Mesin

Fakultas Teknik Universitas Muhammadiyah Surakarta.

3. Bapak Ir. Agus Hariyanto, MT selaku Dosen Pembimbing I yang telah

membimbing, mengarahkan, memberikan petunjuk dalam penyusunan

Tugas Akhir ini dengan sangat perhatian, baik, sabar dan ramah.

4. Bapak Agus Yulianto, ST, MT, selaku Dosen Pembimbing II yang telah

membimbing, mengarahkan, memberikan petunjuk dalam penyusunan

Tugas Akhir ini dengan sangat perhatian, baik, sabar dan ramah.

5. Dosen Jurusan Teknik Mesin Universitas Muhammadiyah Surakarta

yang telah memberikan ilmu pengetahuan kepada penulis selama

mengikuti kegiatan kuliah.

6. Bapak dan Ibu tercinta yang setiap malam selalu mendoakan,

memberikan semangat dan dorongan, serta terima kasih atas semua

nasehat, bimbingan, dan pengorbanan mu selama ini sehingga penulis

x

terpacu untuk menyelesaikan skripsi ini. Semua do’a dan kasih sayang

yang tulus ini akan selalu mengiringi langkahku”

7. Kakak dan adikku yang slalu memberikan semangat,bantuan dan

pengertiannya selama ini.

8. Teman-teman kontrakan Utopia, terima kasih atas segala suka duka

yang mewarnai sebagian hari-hari penulis, semoga persaudaraan ini

bisa berlangsung lebih lama lagi. Amien.

Penulis menyadari bahwa laporan ini masih jauh dari sempurna,

oleh karena itu kritik dan saran yang bersifat membangun dari pembaca

akan penulis terima dengan senang hati.

Wassalamu’alaikum Wr. Wb

Surakarta, 7 Juli 2009

Penulis

xi

DAFTAR ISI

HALAMAN JUDUL............................................................................... i

PERNYATAAN KEASLIAN SKRIPSI.....................................................ii

HALAMAN PERSETUJUAN .............................................................. iii

HALAMAN PENGESAHAN ................................................................. iv

LEMBAR SOAL TUGAS AKHIR...............................................................v

MOTTO ................... ........................................................................... vi

ABSTRAKSI.................... ...................................................................... vii

KATA PENGANTAR............................................................................ viii

DAFTAR ISI .............. ........................................................................... x

DAFTAR GAMBAR ....... ...................................................................... xiii

DAFTAR TABEL ............ ................................................................. xvii

DAFTAR NOTASI............................................................................... xviii

DAFTAR LAMPIRAN.......................................................................... xix

BAB I PENDAHULUAN

1.1. Latar Belakang Masalah .................................................. 1

1.2. Tujuan Penelitian ............................................................. 2

1.3. Manfaat Penelitian .................................................. 3

1.4. Perumusan masalah........................................................... 4

1.5. Batasan Masalah ................................................................ 4

1.6. Sistem Penulisan Laporan .................................................. 5

BAB II TINJAUAN PUSTAKA DAN LANDASAN TEORI

2.1. Kajian Pustaka ................................................................. 7

2.2. Landasan Teori ............................................................... 9

2.2.1. Definisi Komposit ................................................... 9

2.2.2. Klasifikasi Material komposit berdasarkan bentuk

komponen strukturalnya ....................................... 11

2.2.3. Unsur-unsur Utama Pembentuk komposit FRP ... 15

2.2.4. Aspek Geometri ................................................... 22

2.2.5. Perpatahan (Frature) ........................................... 33

xii

BAB III METODOLOGI PENELITIAN

3.1. Persiapan Bahan dan Alat.................................................................. 35

3.1.1. Penyiapan Bahan .................................................... 35

3.1.2. Penyiapan Alat ........................................................ 37

3.2. Diagram Alir..................................................................... . . 40

3.2.1. Survey Lapangan dan study literature .................... 41

3.2.2. Penyiapan Bahan .................................................. 41

3.2.3. Pembuatan Komposit.............................................. 41

3.2.4. Pengujian Komposit ................................................ 45

BAB IV DATA HASIL PENELITIAN DAN PEMBAHASAN

4.1. Pengujian Bending ………………………………………..... 53

4.1.1. Data Hasil Pengujian Bending Alkali 2 jam ……... 53

4.1.1.1. Pembahasan Pengujian bending Alkali 2 jam.. 58

4.1.2. Data Hasil Pengujian Bending Alkali 4 jam …….. 60

4.1.2.1. Pembahasan Pengujian bending Alkali 4 jam... 65

4.1.3. Data Hasil Pengujian Bending Alkali 6 jam……... 67

4.1.3.1. Pembahasan Pengujian bending Alkali 6 jam.. 72

4.1.4. Data Hasil Pengujian Bending Alkali 8 jam …….. 74

4.1.4.1. Pembahasan Pengujian bending Alkali 8 jam... 79

4.2. Pengujian Tarik …………………………………………….. 81

4.2.1. Data Hasil Pengujian Tarik Alkali 2 jam ………… 81

4.2.1.1. Pembahasan Pengujian Tarik Alkali 2 jam …… 83

4.2.2. Data Hasil Pengujian Tarik Alkali 4 jam ………... 84

4.2.2.1. Pembahasan Pengujian Tarik Alkali 4 jam …… 86

4.2.3. Data Hasil Pengujian Tarik Alkali 6 jam…………. 87

4.2.3.1. Pembahasan Pengujian Tarik Alkali 6 jam……. 89

4.2.4. Data Hasil Pengujian Tarik Alkali 8 jam ………… 90

4.2.4.1. Pembahasan Pengujian Tarik Alkali 8 jam……. 92

4.3. Pengujian IMPAK …………………………………………... 93

4.3.1. Data Hasil Pengujian Impak Alkali 2 jam ……… 93

4.3.1.1. Pembahasan Pengujian Impak Alkali 2 jam .... 95

4.3.2. Data Hasil Pengujian Impak Alkali 4 jam …….... 96

xiii


4.3.3. Data Hasil Pengujian Impak Alkali 6 jam ……...... 99

4.3.3.1. Pembahasan Pengujian Impak Alkali 6 jam..... 101

4.3.4. Data Hasil Pengujian Impak Alkali 8 jam …….... 102


4.4. Pengamatan Struktur makro ………………………………. 105

4.4.1. Pembahasan Foto Makro ……………………….... 107

BAB V KESIMPULAN DAN SARAN

5.1. Kesimpulan...................................................................... 109

5.2. Saran................................................................................ 111

DAFTAR PUSTAKA

LAMPIRAN

xiv

DAFTAR GAMBAR

Gambar 2.1 Continous fiber composite .............................................. 11

Gambar 2.2 Woven fiber composite ................................................... 13

Gambar 2.3 Chopped fiber composite ................................................. 14

Gambar 2.4 Hybrid composite ........................................................... 15

Gambar 2.5 Particulate Composite ...................................................... 16

Gambar 2.6 Laminated Composites .................................................... 17

Gambar 2.7 Skema Uji Densitas (Goerge, N B and Brian R. 2003). . 29

Gambar 2.8 Penampang Uji bending (Standart ASTM D 790-02)….. 26

Gambar 2.9 Spesimen dan peralatan uji Impak .................................. 63

Gambar 3.1 Serat rami sebelum diacak ............................................. 85

Gambar 3.2 serat rami setelah diacak ............................................... 86

Gambar 3.3 Resin Polyester Yucalac tipe 157 dan katalis ................. 86

Gambar 3.4 Larutan NaOH ................................................................. 87

Gambar 3.5 Timbangan Digital ......................................................... 87

Gambar 3.6. wood moisture meter ..................................................... 88

Gambar 3.7 Cetakan untuk benda uji ................................................. 88

Gambar 3.8. Alat Pengepres Cetakan ................................................ 89

Gambar 3.9 Alat bantu lain ................................................................. 89

Gambar 3.10. Diagram alir penelitian ..................................................40

Gambar 3.11 Hasil cetakan komposit serat Ramie dengan matrik

polyester ..................................................................... 90

Gambar 3.12 Spesimen uji tarik komposit serat rami. ....................... 91

Gambar 3.13 Spesimen uji bending komposit serat ramie ................. 91

Gambar 3.14 Spesimen uji Impak komposit serat ramie ................... 92

Gambar 3.15 Dimensi pengujian bending Standar ASTM D 790-02. 46

Gambar 3.16. Mesin Pengujian Bending ............................................ 93

Gambar 3.17 Mesin pengujian Impak charpy .................................... 94

Gambar 3.18 Dimensi Impak ASTM D 5942-96 ................................ 94

Gambar 3.19 Dimensi benda pengujian tarik ...................................... 94

Gambar 3.20 Mesin pengujian tarik ................................................... 95

xv

Gambar 4.1 Grafik hubungan momen bending rata-rata dengan fraksi

volume terhadap tebal komposit …………………………. 55

Gambar 4.2 Grafik hubungan tegangan bending rata-rata dengan fraksi

volume terhadap tebal komposit ……………………….. 56

Gambar 4.3 Grafik hubungan defleksi bending rata-rata dengan fraksi

volume terhadap tebal komposit ………………………… 56

Gambar 4.4 Grafik hubungan modulus elastisitas bending rata-rata

dengan fraksi volume terhadap tebal komposit………. 57

Gambar 4.5 Grafik hubungan kekakuan bending rata-rata dengan fraksi

volume terhadap tebal komposit ………………………. 57


volume terhadap tebal komposit ..................................... 62


volume terhadap tebal komposit……………………….. 63


volume terhadap tebal komposit……………………….. 63




volume terhadap tebal komposit………………………. 64






volume terhadap tebal komposit……………………… 70







xvi






dengan fraksi volume terhadap tebal komposit…….. 78



Gambar 4.21 Grafik hubungan modulus elastisitas tarik rata-rata dengan

fraksi volume terhadap tebal komposit………………. 82

Gambar 4.22 Grafik hubungan kekuatan tarik rata-rata dengan fraksi



fraksi volume terhadap tebal komposit……………… 85


volume terhadap tebal komposit………………………85









Gambar 4.29 Grafik hubungan Harga Impak rata-rata dengan fraksi


Gambar 4.30 Grafik Hubungan Energi Serap Impak Rata-rata dengan

Fraksi Volume Terhadap Tebal Komposit…………… 94


volume terhadap tebal komposit…………………….. 97

xvii

Gambar 4.32 Grafik Hubungan Energi Serap ImpakRata-rata dengan

Fraksi Volume Terhadap Tebal Komposit……………97



Gambar 4.34 Grafik Hubungan Energi Serap ImpakRata-rata dengan




Gambar 4.36 Grafik Hubungan Energi Serap Impak Rata-rata dengan


Gambar 4.37 Contoh Patahan Spesimen pada Uji Bending dengan

perbedaan waktu alkali………………………………... 105

Gambar 4.38 Contoh Patahan spesimen pada Uji Impak dengan

perbedaan waktu alkali………………………………… 106

Gambar 4.39 Contoh Patahan spesimen pada Uji Tarik dengan

perbedaan waktu alkali………………………………… 107

xviii

DAFTAR TABEL

Tabel 2.1 Sifat mekanik dari beberapa jenis serat....................................17

Tabel 4.1 Data hasil pengujian bending rata-rata pada tebal 1mm.........53

Tabel 4.2 Data hasil pengujian bending rata-rata pada tebal 2mm.........53

Tabel 4.3 Data hasil pengujian bending rata-rata pada tebal 3mm…….54




Tabel 4.7 Data hasil pengujian bending rata-rata pada tebal 2mm……..60



Tabel 4.10 Data hasil pengujian bending rata-rata pada tebal 5mm……62











Tabel 4.21 Hasil Data Pengujian Tarik Alkali 2 Jam……………………..81




Tabel 4.25 Hasil Data Pengujian Impak Alkali 2 Jam…………………..93




xix

DAFTAR NOTASI

A = Luas Penampang

E = Modulus Elastisitas

Eserap = Energi Yang Terserap

Is = Kekuatan Impak

L = Jarak antara tumpuan

P = Beban Tekan

Vc = Volume Komposit

Vf = Fraksi Volume

mu = Berat Specimen Di udara

ma = Berat Specimen Dalam air

ρair = Densitas air

σ = Tegangan tarik

ΔL = Deformasi/pemanjangan

xx

DAFTAR LAMPIRAN

Lampiran 1. Annual Book of ASTM

Lampiran 2. Data hasil pengujian bending,tarik,dan Impak

Lampiran 3. Analisis perhitungan pengujian bending,tarik,dan Impak

Lampiran 4. Tabel mechanical properties fiber dan resin

Lampiran 5. Uji Density serat rami dengan kadar air 10%

Lampiran 6. Analisis perhitungan fraksi volume

Lampiran 7. Konversi Satuan

Lampiran 8. Gambar mesin pengolahan serat rami

1

BAB I

PENDAHULUAN

1.1. Latar Belakang Masalah

Penggunaan material komposit dengan filler serat alam mulai

banyak dikenal dalam industri manufaktur. Material yang ramah

lingkungan, mampu didaur ulang, serta mampu dihancurkan sendiri

oleh alam merupakan tuntutan teknologi sekarang ini. Salah satu

material yang diharapkan mampu memenuhi hal tersebut adalah

material komposit dengan material pengisi (filler) serat alam.

Keunggulan yang dimiliki oleh serat alam antara lain : non-abbrasive,

densitas rendah, harga lebih murah, ramah lingkungan, dan tidak

membahayakan bagi kesehatan. Penggunaan serat alam sebagai

filler dalam komposit tersebut terutama untuk lebih menurunkan biaya

bahan baku dan peningkatan nilai salah satu produk pertanian. (Fajar,

2008).

Serat alam dapat menjadi filler dalam komposit karena

kandungan selulosa beberapa serat alam yang memiliki selulosa

antara lain kenaf, cantalu, tebu, jagung, abaca, padi, ramie dan lain-

lain. Tanaman ramie ( Boehmeria Nivea ) adalah sumber bahan baku

serat tekstil alam tumbuh-tumbuhan, sebagaimana halnya dengan

serat kapas, linen (flax) dan sejenisnya. Sejak jaman dahulu rami

digunakan untuk bahan pembuat pakaian dan juga sebagai baju

1

2

perang karena keuletan rami mampu menahan sabetan pedang,

bahkan sekarang serat rami diteliti oleh pihak militer untuk bahan

pembuatan baju anti peluru (Jamasri, 2008).

Dalam penelitian ini menggunakan filler serat ramie, jenis

pengikat yang digunakan adalah resin polyester. Resin polyester

merupakan salah satu resin termoset yang mudah diperoleh dan

digunakan masyarakat umum maupun industri skala kecil maupun

besar. Resin polyester ini juga mempunyai kemampuan berikatan

dengan serat alam tanpa menimbulkan reaksi dan gas, oleh karena itu

resin polyester digunakan dalam penelitian ini.

Untuk meningkatkan fungsi guna dari serat ramie yang biasa

digunakan untuk bahan tekstil dan kerajinan rakyat menjadi material

teknik, maka perlu diteliti dan dikembangkan sebagai bahan komposit

yang sesuai sifat fisis dan mekanisnya, sehingga akan tercipta bahan

komposit baru.

1.2. Tujuan Penelitian

Tujuan penelitian ini adalah :

1. Mengetahui kekuatan bending yang paling optimal dari komposit

serat ramie pada fraksi volume serat 20%, 30%, 40%, dan 50%

dengan variasi tebal komposit 1 mm, 2 mm, 3 mm, 4 mm, dan 5

mm, dan perlakuan alkali 2 jam , 4 jam , 6 jam , 8 jam ,bermatrik

resin poliester tipe BQTN 157.

3

2. Mengetahui kekuatan impak yang paling optimal dari komposit

serat ramie pada fraksi volume serat 20%, 30%, 40%, dan 50%

dengan variasi tebal komposit 1 mm, 2 mm, 3 mm, 4 mm, dan 5

mm, dan perlakuan alkali 2 jam , 4 jam , 6 jam , 8 jam ,bermatrik

resin poliester tipe BQTN 157.

3. Mengetahui kekuatan tarik yang paling optimal dari komposit serat

ramie pada fraksi volume serat 20%, 30%, 40%, dan 50% dengan

variasi tebal komposit 1 mm, 2 mm ,3 mm, 4 mm, dan 5 mm, dan

perlakuan alkali 2 jam, 4 jam, 6 jam, 8 jam ,bermatrik resin

poliester tipe BQTN 157.

4. Mengetahui jenis patahan pengujian bending , impak dan tarik

dengan foto makro.

1.3. Manfaat Penelitian

Manfat dari penelitian ini adalah sebagai berikut:

1. Bagi peneliti adalah untuk menambah pengetahuan, wawasan dan

pengalaman tentang penelitian material komposit.

2. Bagi akademik, penelitian ini dapat digunakan sebagai referensi

tambahan untuk penelitian tentang komposit serat alam (natural

fibrous composite).

3. Bagi industry dapat digunakan sebagai acua atau pedoman dalam

pembuatan komposit yang terbuat dari serat alam, khusunya serat

4

ramie sehingga meningkatkan nilai jual serat ramie sekaligus

meningkatkan pendapatan masyarakat khususnya petani ramie.

1.4. Rumusan Masalah

Komposit Penguatan Serat (Fibrous Composite) menggunakan

serat ramie yang disusun secara acak dan matrik resin polyester

sebagai pembentuk material komposit, dengan adanya penambahan

fraksi volume dan penambahan variasi tebal, serta perlakuan alkali

bagaimanakah performasi dari bahan serat komposit ini? Bagaimana

jenis patahan specimen hasil pengujian bendin, impak dan tarik?

Permasalahan-permasalahan tersebut akan menjadi topik utama

penelitian ini.

1.5. Pembatasan Masalah

Agar masalah tidak melebar dari pembahasan utama, maka

permasalahan hanya dibatasi pada:

1. Pengujian komposit pada serat ramie yang disusun acak dengan

fraksi volume serat 20%, 30%, 40%, dan 50% dan dengan variasi

tebal komposit 1mm, 2mm, 3mm, 4mm, dan5 mm, dan perlakuan

alkali 2 jam, 4 jam, 6 jam, 8 jam dengan matrik resin polyester tipe

BQTN 157.

2. Jenis komposit yang dijadikan sebagai bahan penelitian pada

tugas akhir ini adalah jenis fibrous komposit (komposit serat).

5

3. Pengujian komposit berupa uji kekuatan bending (Standart ASTM

D 790-02), uji impak (Standart ASTM D 256-00) dan uji tarik

(Standart ASTM D 638-02).

4. Benda uji dibuat dengan cara press mold dan menggunakan kaca

sebagai cetakan.

5. Serat dengan perlakuan Alkali 2 jam, 4 jam, 6 jam, dan 8 jam.

1.6. Sistematika Penulisan Laporan

Laporan penulisan Tugas Akhir ini disusun dengan sistematika

sebagai berikut:

BAB I PENDAHULUAN

Berisi tentang latar belakang, tujuan penelitian, manfaat

penelitian, perumusan masalah, pembatasan masalah, dan

sistematika penulisan laporan.

BAB II TINJAUAN PUSTAKA DAN LANDASAN TEORI

Bab ini berisi tentang tinjauan pustaka dan dasar teori.

Tinjauan pustaka memuat uraian sistematis tentang hasil-hasil riset

yang didapat oleh peneliti terdahulu dan berhubungan dengan

penelitian ini. Dasar teori ini dijadikan sebagai penuntun untuk

memecahkan masalah yang berbentuk uraian kualitatif atau model

matematis.

6

BAB III PELAKSANAAN PENGUJIAN

Bab ini berisi tentang diagram alur penelitian, penyiapan benda

uji, pembuatan benda uji, serta pengujian mekanis komposit.

BAB IV HASIL PENELITIAN DAN PEMBAHASAN

Bab ini berisi tentang hasil dan pembahasan pengujian

bending, impak, dan tarik dan pengamatan foto makro, serta analisis

perhitungan.

BAB V KESIMPULAN DAN SARAN

Bab ini berisi tentang kesimpulan dan saran.

DAFTAR PUSTAKA

LAMPIRAN

7

BAB II

LANDASAN TEORI

2.1. Tinjauan pustaka

Nurkholis (2008), meneliti kekuatan tarik dan impak komposit

berpenguat serat rami dengan perlakuan alkali (NaOH) selama 2, 4, 6

dan 8 jam dengan fraksi volume serat 10% dan 90% bermatrik poliester

BQTN 157, pembuatan komposit dilakukan dengan pencetakan

metode hand lay up menggunakan kaca sebagai cetakannya dan

perlakuan post cure 600 selama 4jam, diperoleh kekuatan tarik tertinggi

dimiliki oleh komposit serat rami dengan perlakuan alkali 8 jam yaitu

sebesar 41,9 MPa dengan modulus elastisitas 2743,15 MPa pada

perlakuan alkali 2jam, harga impak tertinggi terjadi pada perlakuan

alkali 4 jam yaitu sebesar 0,0725 J/mm2.

Fajar (2008), meneliti kekuatan bending dan impak komposit

serat rami susun acak dengan matrik polyester BQTN 157 tanpa

perlakuan alkali, pembuatan komposit dilakukan dengan metode pres

mold. Dari hasil pengujian diperoleh sebagai berikut : pengujian

bending didapat nilai tegangan bending rata-rata tertinggi dimiliki oleh

komposit dengan Vf 50% pada tebal 5mm sebesar 95,33 MPa dan

terendah pada komposit dengan Vf 20% pada tebal 4mm sebesar

44,52 MPa, modulus elastisitas bending rata-rata tertinggi dimiliki oleh

komposit dengan Vf 40% pada tebal 1mm sebesar 5462,93 MPa dan

7

8

terendah pada komposit dengan Vf 20% pada tebal 4mm. Untuk harga

impak rata-rata tertinggi dimiliki oleh komposit dengan Vf 20% pada

tebal 1mm sebesar 0,119 J/mm2 dan terendah pada komposit dengan

Vf 40% pada tebal 5mm sebesar 0,024 J/mm2.

Junaedi (2008), menguji kekuatan tarik dan impak komposit

berpenguat serat rami dengan variasi panjang serat 25mm, 50mm dan

100mm dengan fraksi volume 90% matrik poliester BQTN 157 dan 10%

serat rami, pembuatan komposit dengan cara prees mold. Diperoleh

kekuatan tarik tertinggi pada komposit dengan panjang serat 100mm

yaitu 52,483 MPa, dengan modulus elastisitas 5577,213 MPa, harga

impak tertinggi dimiliki oleh komposit dengan panjang serat 50mm yaitu

0,087 J/mm2.

Ditinjau dari penelitian yang telah dilakukan diatas, maka dapat

disimpulkan bahwa kekuatan bending, impak dan tarik dipengaruhi oleh

adanya variasi fraksi volume (Vf) semakin tinggi fraksi volumenya maka

semakin tinggi pula kekuatannya. Maka dari itu penulis mencoba

meneliti komposit berpenguat serat rami acak dengan perlakuan alkali

2jam, 4jam, 6jam dan 8jam, dengan variasi fraksi volume serat (Vf)

20%, 30%, 40% dan 50% bermatrik polyester BQTN 157, terhadap

variasi tebal komposit 1mm, 2mm, 3mm, 4mm dan 5mm.

9

2.2. Landasan Teori

2.2.1. Definisi Komposit

Kata komposit berasal dari kata “to compose” yang berarti

menyusun atau menggabung. Secara sederhana bahan komposit

berarti bahan gabungan dari dua atau lebih bahan yang berlainan. Jadi

komposit adalah suatu bahan yang merupakan gabungan atau

campuran dari dua material atau lebih pada skala makroskopis untuk

membentuk material ketiga yang lebih bermanfaat. Komposit dan alloy

memiliki perbedaan dari cara penggabungannya yaitu apabila komposit

digabung secara makroskopis sehingga masih kelihatan serat maupun

matriknya (komposit serat) sedangkan pada alloy / paduan digabung

secara mikroskopis sehingga tidak kelihatan lagi unsur-unsur

pendukungnya ( Jones, 1975).

Sesungguhnya ribuan tahun lalu material komposit telah

dipergunakan dengan memanfaatkannya serat alam sebagai penguat.

Dinding bangunan tua di Mesir yang telah berumur lebih dari 3000

tahun ternyata terbuat dari tanah liat yang diperkuat jerami (Jamasri,

2008). Seorang petani memperkuat tanah liat dengan jerami, para

pengrajin besi membuat pedang secara berlapis dan beton bertulang

merupakan beberapa jenis komposit yang sudah lama kita kenal.

Komposit dibentuk dari dua jenis material yang berbeda, yaitu:

1. Penguat (reinforcement), yang mempunyai sifat kurang ductile

tetapi lebih rigid serta lebih kuat.

10

2. Matrik, umumnya lebih ductile tetapi mempunyai kekuatan dan

rigiditas yang lebih rendah.

Pada material komposit sifat unsur pendukungnya masih terlihat

dengan jelas, sedangkan pada alloy / paduan sudah tidak kelihatan lagi

unsur-unsur pendukungnya. Salah satu keunggulan dari material

komposit bila dibandingkan dengan material lainnya adalah

penggabungan unsur-unsur yang unggul dari masing-masing unsur

pembentuknya tersebut. Sifat material hasil penggabungan ini

diharapkan dapat saling melengkapi kelemahan-kelemahan yang ada

pada masing-masing material penyusunnya. Sifat-sifat yang dapat

diperbaharui (Jones,1975) antara lain :

Sifat-sifat yang dapat diperbaiki antara lain:

a. kekuatan (Strength)

b. kekakuan (Stiffness)

c. ketahanan korosi (Corrosion resistance)

d. ketahanan gesek/aus (Wear resistance)

e. berat (Weight)

f. ketahanan lelah (Fatigue life)

g. Meningkatkan konduktivitas panas

h. Tahan lama

Secara alami kemampuan tersebut diatas tidak ada semua pada

waktu yang bersamaan (Jones, 1975). Sekarang ini perkembangan

teknologi komposit mulai berkembang dengan pesat. Komposit

11

sekarang ini digunakan dalam berbagai variasi komponen antara lain

untuk otomotif, pesawat terbang, pesawat luar angkasa, kapal dan alat-

alat olah raga seperti ski, golf, raket tenis dan lain-lain.

2.2.2. Klasifikasi Material Komposit Berdasarkan bentuk

komponen strukturalnya

Secara garis besar komposit diklasifikasikan menjadi tiga

macam (Jones, 1975), yaitu:

1. Komposit serat (Fibrous Composites)

2. Komposit partikel (Particulate Composites)

3. Komposit lapis (Laminates Composites)

2.2.2.1. Komposit serat (Fibrous Composites)

Komposit serat adalah komposit yang terdiri dari fiber

dalam matriks. Secara alami serat yang panjang mempunyai

kekuatan yang lebih dibanding serat yang berbentuk curah

(bulk). Merupakan jenis komposit yang hanya terdiri dari satu

lamina atau satu lapisan yang menggunakan penguat berupa

serat / fiber. Fiber yang digunakan bisa berupa fibers glass,

carbon fibers, aramid fibers (poly aramide), dan sebagainya.

Fiber ini bisa disusun secara acak maupun dengan orientasi

tertentu bahkan bisa juga dalam bentuk yang lebih kompleks

seperti anyaman. Serat merupakan material yang mempunyai

perbandingan panjang terhadap diameter sangat tinggi serta

12

diameternya berukuran mendekati kristal. serat juga

mempunyai kekuatan dan kekakuan terhadap densitas yang

besar (Jones, 1975).

Kebutuhan akan penempatan serat dan arah serat yang

berbeda menjadikan komposit diperkuat serat dibedakan lagi

menjadi beberapa bagian diantaranya:

1) Continous fiber composite (komposit diperkuat dengan

serat kontinue).

Gambar 2.1. Continous fiber composite (Gibson, 1994)

2) Woven fiber composite (komposit diperkuat dengan serat

anyaman).

Gambar 2.2. Woven fiber composite (Gibson, 1994)

3) Chopped fiber composite (komposit diperkuat serat

pendek/acak)

13

Gambar 2.3. Chopped fiber composite (Gibson, 1994)

4) Hybrid composite (komposit diperkuat serat kontinyu

dan serat acak).

Gambar 2.4. Hybrid composite (Gibson, 1994)

2.2.2.2. Komposit Partikel (Particulate Composites)

Merupakan komposit yang menggunakan partikel serbuk

sebagai penguatnya dan terdistribusi secara merata dalam

matriknya.

Gambar 2.5. Particulate Composite

(www.kemahasiswaan.its.ac.id)

Komposit ini biasanya mempunyai bahan penguat yang

dimensinya kurang lebih sama, seperti bulat serpih, balok,

serta bentuk-bentuk lainnya yang memiliki sumbu hampir

14

sama, yang kerap disebut partikel, dan bisa terbuat dari satu

atau lebih material yang dibenamkan dalam suatu matriks

dengan material yang berbeda. Partikelnya bisa logam atau

non logam, seperti halnya matriks. Selain itu adapula polimer

yang mengandung partikel yang hanya dimaksudkan untuk

memperbesar volume material dan bukan untuk kepentingan

sebagai bahan penguat (Jones, 1975).

2.2.2.3. Komposit Lapis (Laminates Composites)

Merupakan jenis komposit terdiri dari dua lapis atau lebih

yang digabung menjadi satu dan setiap lapisnya memiliki

karakteristik sifat sendiri.

Gambar 2.6. Laminated Composites

(www.kemahasiswaan.its.ac.id)

Komposit ini terdiri dari bermacam-macam lapisan

material dalam satu matriks. Bentuk nyata dari komposit

lamina adalah:( Jones, 1999)

1. Bimetal

Bimetal adalah lapis dari dua buah logam yang mempunyai

koefisien ekspansi thermal yang berbeda. Bimetal akan

15

melengkung seiring dengan berubahnya suhu sesuai

dengan perancangan, sehingga jenis ini sangat cocok

untuk alat ukur suhu.

2. Pelapisan logam

Pelapisan logam yang satu dengan yang lain dilakukan

untuk mendapatkan sifat terbaik dari keduanya.

3. Kaca yang dilapisi

Konsep ini sama dengan pelapisan logam. Kaca yang

dilapisi akan lebih tahan terhadap cuaca.

4. Komposit lapis serat

Dalam hal ini lapisan dibentuk dari komposit serat dan

disusun dalam berbagai orientasi serat. Komposit jenis ini

biasa digunakan untuk panel sayap pesawat dan badan

pesawat.

2.2.3. Unsur-unsur Utama Pembentuk Komposit FRP

FRP (Fiber Reinforced Plastics) mempunyai dua

unsur bahan yaitu serat (fiber) dan bahan pengikat serat

yang disebut dengan matriks. Unsur utama dari bahan

komposit adalah serat, serat inilah yang menentukan

karakteristik suatu bahan seperti kekuatan, keuletan,

kekakuan dan sifat mekanik yang lain. Serat menahan

sebagian besar gaya yang bekerja pada material komposit,

16

sedangkan matriks mengikat serat, melindungi dan

meneruskan gaya antar serat (Van Vlack, 2005)

Secara prinsip, komposit dapat tersusun dari

berbagai kombinasi dua atau lebih bahan, baik bahan

logam, bahan organik, maupun bahan non organik. Namun

demikian bentuk dari unsur-unsur pokok bahan komposit

adalah fibers, particles, leminae or layers, flakes fillers and

matrix. Matrik sering disebut unsur pokok body, karena

sebagian besar terdiri dari matriks yang melengkapi

komposit (Van vlack, 2005).

2.2.3.1. Serat

Serat atau fiber dalam bahan komposit berperan

sebagai bagian utama yang menahan beban, sehingga

besar kecilnya kekuatan bahan komposit sangat tergantung

dari kekuatan serat pembentuknya. Semakin kecil bahan

(diameter serat mendekati ukuran kristal) maka semakin

kuat bahan tersebut, karena minimnya cacat pada material

(Triyono,& Diharjo k, 2000).

Selain itu serat (fiber) juga merupakan unsur yang

terpenting, karena seratlah nantinya yang akan menentukan

sifat mekanik komposit tersebut seperti kekakuan, keuletan,

kekuatan dsb. Fungsi utama dari serat adalah:

17

Sebagai pembawa beban. Dalam struktur komposit 70% -

90% beban dibawa oleh serat.

Memberikan sifat kekakuan, kekuatan, stabilitas panas dan

sifat-sifat lain dalam komposit.

Memberikan insulasi kelistrikan (konduktivitas) pada

komposit, tetapi ini tergantung dari serat yang digunakan.

Tabel 2.1. Sifat mekanik dari beberapa jenis serat.( Dieter H. Mueller )

Cotton Flax Jute Kenaf E-Glass Ramie Sisal

Diameter mm - 11–33 200 200 5–25 40–80 50–

200

Panjang mm 10–60 10–40 1–5 2–6 - 60–260 1–5

Kekuatan tarik MPa 330–

585

345–

1035

393–

773 930 1800

400–

1050

511–

635

Modulus

elastisitas GPa

4.5–

12.6

27.6–

45.0 26.5 53.0

69.0–

73.0 61.5

9.4–

15.8

Massa jenis g/cm3

1.5–

1.54

1.43–

1.52

1.44–

1.50 1.5 2.5 1.5–1.6

1.16–

1.5

Regangan

maksimum % 7.0–8.0 2.7–3.2

1.5–

1.8 1.6 2.5–3.0 3.6–3.8

2.0–

2.5

Spesifik

kekuatan tarik km 39.2 73.8 52.5 63.2 73.4 71.4 43.2

Spesifik

kekakuan km 0.85 3.21 1.80 3.60 2.98 4.18 1.07

2.2.3.1. Matrik

Menurut Gibson (1994), bahwa matrik dalam struktur

komposit dapat berasal dari bahan polimer, logam, maupun

keramik.

Syarat pokok matrik yang digunakan dalam komposit

adalah matrik harus bisa meneruskan beban, sehinga serat

harus bisa melekat pada matrik dan kompatibel antara serat

18

dan matrik. Umumnya matrik dipilih yang mempunyai

ketahanan panas yang tinggi (Triyono & Diharjo, 2000).

Matrik yang digunakan dalam komposit adalah harus

mampu meneruskan beban sehingga serat harus bisa melekat

pada matrik dan kompatibel antara serat dan matrik artinya

tidak ada reaksi yang mengganggu. Menurut Diharjo (1999)

pada bahan komposit matrik mempunyai kegunaan yaitu

sebagai berikut :

Matrik memegang dan mempertahankan serat pada

posisinya.

Pada saat pembebanan, merubah bentuk dan

mendistribusikan tegangan ke unsur utamanya yaitu serat.

Memberikan sifat tertentu, misalnya ductility, toughness

dan electrical insulation.

Menurut Diharjo (1999), bahan matrik yang sering

digunakan dalam komposit antara lain :

a. Polimer.

Polimer merupakan bahan matrik yang paling sering

digunakan. Adapun jenis polimer yaitu:

Thermoset, adalah plastik atau resin yang tidak bisa

berubah karena panas (tidak bisa di daur ulang).

Misalnya : epoxy, polyester, phenotic.

19

Termoplastik, adalah plastik atau resin yang dapat

dilunakkan terus menerus dengan pemanasan atau

dikeraskan dengan pendinginan dan bisa berubah

karena panas (bisa didaur ulang). Misalnya :

Polyamid, nylon, polysurface, polyether.

b. Keramik.

Pembuatan komposit dengan bahan keramik yaitu

Keramik dituangkan pada serat yang telah diatur

orientasinya dan merupakan matrik yang tahan pada

temperatur tinggi. Misalnya :SiC dan SiN yang sampai

tahan pada temperatur 1650 C.

c. Karet.

Karet adalah polimer bersistem cross linked yang

mempunyai kondisi semi kristalin dibawah temperatur

kamar.

d. Matrik logam

Matrik cair dialirkan kesekeliling sistem fiber, yang telah

diatur dengan perekatan difusi atau pemanasan.

e. Matrik karbon.

Fiber yang direkatkan dengan karbon sehingga terjadi

karbonisasi.

Pemilihan matrik harus didasarkan pada kemampuan

elongisasi saat patah yang lebih besar dibandingkan dengan

20

filler. Selain itu juga perlunya diperhatikan berat jenis,

viskositas, kemampuan membasahi filler, tekanan dan suhu

curring, penyusutan dan voids.

Voids (kekosongan) yang terjadi pada matrik sangatlah

berbahaya, karena pada bagian tersebut fiber tidak didukung

oleh matriks, sedangkan fiber selalu akan mentransfer

tegangan ke matriks. Hal seperti ini menjadi penyebab

munculnya crack, sehingga komposit akan gagal lebih awal.

Kekuatan komposit terkait dengan void adalah berbanding

terbalik yaitu semakin banyak void maka komposit semakin

rapuh dan apabila sedikit void komposit semakin kuat.

Dalam pembuatan sebuah komposit, matriks berfungsi

sebagai pengikat bahan penguat, dan juga sebagai pelindung

partikel dari kerusakan oleh faktor lingkungan. Beberapa

bahan matriks dapat memberikan sifat-sifat yang diperlukan

sebagai keliatan dan ketangguhan. Pada penelitian ini matrik

yang digunakan adalah polimer termoset dengan jenis resin

polyester.

Matriks polyester paling banyak digunakan terutama

untuk aplikasi konstruksi ringan, selain itu harganya murah,

resin ini mempunyai karakteristik yang khas yaitu dapat

diwarnai, transparan, dapat dibuat kaku dan fleksibel, tahan

air, tahan cuaca dan bahan kimia. Polyester dapat digunakan

21

pada suhu kerja mencapai 79 0C atau lebih tergantung partikel

resin dan keperluannya (Schward, 1984). Keuntungan lain

matriks polyester adalah mudah dikombinasikan dengan serat

dan dapat digunakan untuk semua bentuk penguatan plastik.

2.2.3.2. Perlakuan Alkali ( NaOH )

Sifat alami serat adalah Hyrophilic, yaitu suka terhadap

air berbeda dari polimer yang hidrophilic.Pengaruh perlakuan

alkali terhadap sifat permukaan serat alam selulosa telah

diteliti dimana kandungan optimum air mampu direduksi

sehingga sifat alami hidropholic serat dapat memberikan

ikatan interfecial dengan matrik secra optimal (Bismarck dkk

2002).

NaOH merupakan larutan basa yang tergolong mudah

larut dalam air dan termasuk basa kuat yang dapat terionisasi

dengan sempurna. Menurut teori arrhenius basa adalah zat

yang dalam air menghasilkan ion OH negatif dan ion positif.

Larutan basa memiliki rasa pahit, dan jika mengenai tangan

terasa licin (seperti sabun). Sifat licin terhadap kulit itu disebut

sifat kaustik basa.

Salah satu indikator yang digunakan untuk menunjukkkan

kebasaan adalah lakmus merah. Bila lakmus merah

22

dimasukkan ke dalam larutan basa maka berubah menjadi

biru.

2.2.4. Aspek Geometri

2.2.4.1. Pengujian Kadar Air

Pengujian ini adalah untuk mengetahui jumlah kadar air yang

terdapat pada serat rami. Uji ini bertujuan untuk menjaga agar

serat rami tetap terjaga kadar airnya yaitu 10%. Pengujian ini

menggunakan alat digital wood moisture contain. Pengujian ini

mempunyai dua fungsi utama yaitu (standar ASTM D 570-98) :

1. Sebagai panduan mengenai proporsi air yang diserap

oleh sebuah bahan.

2. Sebagai tes control mengenai keseragaman sebuah

produk.

2.2.4.2. Fraksi Volume

Jumlah kandungan serat dalam komposit, merupakan hal

yang menjadi perhatian khusus pada komposit berpenguat serat.

Untuk memperoleh komposit berkekuatan tinggi, distribusi serat

dengan matrik harus merata pada proses pencampuran agar

mengurangi timbulnya void. Untuk menghitung fraksi volume,

parameter yang harus diketahui adalah berat jenis resin, berat

jenis serat, berat komposit dan berat serat. Adapun fraksi volume

yang ditentukan dengan persamaan (Harper, 1996) :

23

................................................. [2.1]

...................................................... [2.2]

Jika selama pembuatan komposit diketahui massa fiber

dan matrik, serta density fiber dan matrik, maka fraksi volume dan

fraksi massa fiber dapat dihitung dengan persamaan

(Shackelford, 1992) :

........................................................... [2.3]

dimana :

Wf : fraksi berat serat

wf : berat serat

wc : berat komposit

ρf : density serat

ρc : density komposit

Vf : fraksi volume serat

Vm : fraksi volume matrik

vf : volume serat

vm : volume matrik

2.2.4.3. Uji density

Pengujian densitas merupakan pengujian sifat fisis terhadap

spesimen, yang bertujuan untuk mengetahui nilai kerapatan massa dari

24

spesimen yang diuji. Rapat massa (mass density) suatu zat adalah

massa zat per satuan volume (Goerge, 2003).

𝜌 =𝑚

𝑣

dimana :

ρ = densitas benda (gram/cm3)

m = massa benda (gram)

v = volume benda (cm3)

Pada benda dengan bentuk yang tidak beraturan, dimana kita

kesulitan untuk menentukan volumenya, kita dapat menghitung

densitas dengan hukum Archimedes. Dalam pengujian densitas disini

pada prinsipnya menentukan massa spesimen diudara (mudara) dan

massa spesimen diair (mair). Massa diudara (mudara) dapat dihitung

dengan timbangan digital secara normal yang merupakan massa

sesungguhnya. Massa dalam air (mair) dapat dihitung dengan cara

massa diudara (mudara) dikurangi gaya keatas, sedangkan gaya ke atas

dapat dihitung dengan teori Archimides. Pada teori Archimides

dikatakan bahwa suatu benda yang dicelupkan dalam suatu fluida akan

mengalami gaya ke atas sama dengan massa fluida yang dipindahkan

oleh benda. Jadi dari teori Archimides tersebut dapat diterapkan untuk

mencari densitas dengan persamaan rumus perhitungan seperti

dibawah ini (Barsoum, 1997) :

𝜌 = 𝑚𝑢𝑑𝑎𝑟𝑎

(𝑚𝑢𝑑𝑎𝑟𝑎 −𝑚𝑓𝑙𝑢𝑖𝑑𝑎 )/𝜌𝑓𝑙𝑢𝑖𝑑𝑎

25

dimana :

mudara = massa spesimen diudara (gram)

mfluida = massa spesimen dalam fluida/air (gram)

ρfluida = densitas fluida/air (gram/cm3)

ρ = densitas spesimen (gram/cm3)

Gambar 2.7. Skema Uji Densitas (Goerge, 2003).

2.2.4.4. Kekuatan Bending

Material komposit mempunyai sifat tekan lebih baik

dibanding tarik, pada perlakuan uji bending spesimen, bagian atas

spesimen terjadi proses tekan dan bagian bawah terjadi proses

tarik sehingga kegagalan yang terjadi akibat uji bending yaitu

mengalami patah bagian bawah karena tidak mampu menahan

tegangan tarik. Dimensi balok dapat kita lihat pada gambar 2.7.

berikut ini : (Standart ASTM D 790-02 ).

26

Gambar 2.8. Penampang Uji bending (Standart ASTM D 790-02)

Momen yang terjadi pada komposit dapat dihitung

dengan persamaan :

𝑀 = 𝑃2 . 𝐿 2 …………………………………………………….. [2.4]

Menentukan kekuatan bending menggunakan persamaan

(Standart ASTM D790-02) :

𝜎 =𝑀.𝑌

𝐼

=

𝑃2 .

𝐿2 .

12 𝑑

112 . 𝑏 . 𝑑3

=

18 . 𝑃 . 𝐿 .𝑑

112 . 𝑏 . 𝑑3

=

18 𝑃 . 𝐿

112 𝑏 . 𝑑2

𝜎𝑏

=3 𝑃 . 𝐿

2 . 𝑏 . 𝑑2………………………………………………… . .…… . [2.5]

Sedangkan untuk menentukan modulus elastisitas bending

menggunakan rumus sebagai berikut (Standart ASTM D790- 02) :

P

2

27

...4

.3

3

db

PLEb ………………………....…….............……….[2.6]

dimana:

b = kekuatan bending (MPa)

P = beban yang diberikan(N)

L = jarak antara titik tumpuan (mm)

b = lebar spesimen (mm)

d = tebal spesimen (mm)

δ = defleksi (mm)

Eb = modulus elastisitas (MPa)

Sedangkan kekakuan dapat dicari dengan persamaan

(Lukkassen, D., Meidel, A., 2003) :

𝐼 =1

12𝑏𝑑3 ........................................................................... [2.7]

D = EI ................................................................................. [2.8]

dimana :

D : kekakuan (N/mm2)

E : modulus elastisitas (N/mm2)

I : momen inersia (mm4)

b : lebar (mm)

d : tinggi (mm)

28

2.2.4.5. Kekuatan Impak

Pengujian impak bertujuan untuk mengukur berapa energi

yang dapat diserap suatu material sampai material tersebut patah.

Pengujian impak merupakan respon terhadap beban kejut atau

beban tiba-tiba (beban impak) (calliester, 2007).

Dalam pengujian impak terdiri dari dua teknik pengujian

standar yaitu Charpy dan Izod. Pada pengujian standar Charpy

dan Izod, dirancang dan masih digunakan untuk mengukur energi

impak yang juga dikenal dengan ketangguhan takik (Calliester,

2007).

Spesimen Charpy berbentuk batang dengan penampang

lintang bujur sangkar dengan takikan V oleh proses permesinan

(gambar 2.2.a). Mesin pengujian impak diperlihatkan secara

skematik dengan (gambar 2.2.b). Beban didapatkan dari

tumbukan oleh palu pendulum yang dilepas dari posisi ketinggian

h. Spesimen diposisikan pada dasar seperti pada (gambar 2.2.b)

tersebut. Ketika dilepas, ujung pisau pada palu pendulum akan

menabrak dan mematahkan spesimen ditakikannya yang bekerja

sebagai titik konsentrasi tegangan untuk pukulan impak

kecepatan tinggi. Palu pendulum akan melanjutkan ayunan untuk

mencapai ketinggian maksimum h’ yang lebih rendah dari h.

Energi yang diserap dihitung dari perbedaan h’ dan h (mgh –

mgh’), adalah ukuran dari energi impak. Posisi simpangan lengan

29

pendulum terhadap garis vertikal sebelum dibenturkan adalah α

dan posisi lengan pendulum terhadap garis vertikal setelah

membentur spesimen adalah β. Dengan mengetahui besarnya

energi potensial yang diserap oleh material maka kekuatan impak

benda uji dapat dihitung (Standar ASTM D256-00).

Eserap = energi awal – energi yang tersisa

= m.g.h – m.g.h’

= m.g.(R-Rcos α) – m.g.(R- R.cos β)

Esrp = mg.R.(cos β - cos α) ..........................................[2.9]

dimana :

Esrp : energi serap (J)

m : berat pendulum (kg) = 20 kg

g : percepatan gravitasi (m/s2) = 10 m/s2

R : panjang lengan (m) = 0,8 m

α : sudut pendulum sebelum diayunkan = 30o

β : sudut ayunan pendulum setelah mematahkan

specimen

Harga impak dapat dihitung dengan :

𝐻𝐼 =𝐸𝑠𝑟𝑝

𝐴𝑜 ................................................................................. [2.10]

dimana :

HI : Harga Impak (J/mm2)

Esrp : energi serap (J)

Ao : Luas penampang (mm2)

30

Gambar 2.9. (a) Spesimen yang digunakan untuk pengujian

impak. (b) Skematik peralatan uji impak. (Callister, 2007).

Pengujian impak dapat diidentifikasi sebagai berikut :

1. Material yang getas, bentuk patahannya akan bermukaan

merata, hal ini menunjukkan bahwa material yang getas akan

cenderung patah akibat tegangan normal.

2. Material yang ulet akan terlihat meruncing, hal ini menunjukkan

bahwa material yang ulet akan patah akibat tegangan geser.

3. Semakin besar posisi sudut β akan semakin getas, demikian

sebaliknya. Artinya pada material getas, energy untuk

31

mematahkan material cenderung semakin kecil, demikian

sebaliknya.

2.2.4.6. Pengujian Kekuatan Tarik

Pengujian tarik bertujuan untuk mengetahui tegangan,

regangan, modulus elastisitas bahan dengan cara menarik

spesimen sampai putus. Pengujian tarik dilakukan dengan mesin

uji tarik atau dengan universal testing standar.(Standar ASTM D

638-02).

Hal-hal yang mempengaruhi kekuatan tarik komposit

antara lain :(Surdia, 1995).

a. Temperatur

Apabila temperatur naik, maka kekuatan tariknya akan turun

b. Kelembaban

Pengaruh kelembaban ini akan mengakibatkan

bertambahnya absorbsi air, akibatnya akan menaikkan

regangan patah, sedangkan tegangan patah dan modulus

elastisitasnya menurun.

c. Laju Tegangan

d. Apabila laju tegangan kecil, maka perpanjangan

bertambah dan mengakibatkan kurva tegangan-regangan

menjadi landai, modulus elastisitasnya rendah. Sedangkan

kalau laju tegangan tinggi, maka beban patah dan modulus

elastisitasnya meningkat tetapi regangannya mengecil.

32

Hubungan antara tegangan dan regangan pada beban tarik

ditentukan dengan rumus sebagai berikut (Surdia, 1995)

P = σ . A atau σ = A

P ..................................................... [2.11]

Catatan:

P = beban (N)

A = luas penampang (mm2)

σ = tegangan (MPa).

Besarnya regangan adalah jumlah pertambahan panjang

karena pembebanan dibandingkan dengan panjang daerah

ukur (gage length). Nilai regangan ini adalah regangan

proporsional yang didapat dari garis. Proporsional pada

grafik tegangan-tegangan hasil uji tarik komposit.(Surdia,

1995)

= lo

L ......................................................................... [2.12]

Dimana:

= Regangan (mm/mm)

ΔL = pertambahan panjang (mm)

lo = panjang daerah ukur (gage length), mm

Pada daerah proporsional yaitu daerah dimana tegangan-

regangan yang terjadi masih sebanding, defleksi yang terjadi

masih bersifat elastis dan masih berlaku hukum Hooke.

Besarnya nilai modulus elastisitas komposit yang juga

33

merupakan perbandingan antara tegangan dan regangan

pada daerah proporsional dapat dihitung dengan persamaan

(Surdia, 1995)

E =

........................................................................... [2.13]

Dimana:

E = Modulus elastisitas tarik (MPa)

= Kekuatan tarik (MPa)

= Regangan (mm/mm)

2.2.5. Perpatahan (Fracture)

2.2.5.1 Dasar-dasar Perpatahan.

Kegagalan dari bahan teknik hampir selalu tidak

diinginkan terjadi karena beberapa alasan seperti

membahayakan hidup manusia, kerugian dibidang ekonomi dan

gangguan terhadap ketersediaan produk dan jasa. Meskipun

penyebab kegagalan dan sifat bahan mungkin diketahui,

pencegahan terhadap kegagalan sulit untuk dijamin. Kasus

yang sering terjadi adalah pemilihan bahan dan proses yang

tidak tepat dan perancangan komponen kurang baik serta

penggunaan yang salah. Menjadi tanggung jawab para insinyur

untuk mengantisipasi kemungkinan kegagalan dan mencari

penyebab pada kegagalan untuk mencegah terjadinya

kegagalan lagi(Calliester, 2007).

34

Patah sederhana didefinisikan sebagai pemisahan

sebuah bahan menjadi dua atau lebih potongan sebagai respon

dari tegangan static yang bekerja dan pada temperatur yang

relative rendah terhadap temperatur cairnya. Dua model patah

yang mungkin terjadi pada bahan teknik adalah patah liat

(ductile fracture) dan patah getas (brittle fracture). Klasifikasi ini

didasarkan pada kemampuan bahan mengalami deformasi

plastik. Bahan liat (ductile) memperlihatkan deformasi plastik

dengan menyerap energi yang besar sebelum patah.

Sebaliknya, patah getas hanya memeperlihatkan deformasi

plastik yang kecil atau bahkan tidak ada. Setiap proses

perpatahan meliputi dua tahap yaitu pembentukan dan

perambatan sebagai respon terhadap tegangan yang

diterapkan. Jenis perpatahan sangat tergantung pada

mekanisme perambatan retak (Callister, 2007).

35

BAB III

PELAKSANAAN PENELITIAN

3.1. Penyiapan Bahan dan Alat

3.1.1. Penyiapan bahan

Bahan yang digunakan dalam penelitian ini adalah sebagai berikut:

a. Serat rami

Serat rami dicuci dahulu untuk menghilangkn kotoran yang

ada pada serat, kemudian serat dijemur. Setelah melalui proses

penjemuran serat dioven sampai kadar air menjadi 10%.

Gbr 3.1. Serat rami sebelum diacak

Gbr 3.2. serat rami setelah diacak

35

36

b. Poliester

Matrik yang digunakan Resin Polyester BQTN tipe 157

dengan bahan tambahan katalis yang berfungsi sebagai pengeras

resin.

Gambar 3.3. Resin Polyester Yucalac tipe 157 dan katalis

c. NaOH

NaOH digunakan untuk menghilangkan kotoran atau lignin

pada serat dengan kadar 5 %. NaOH merupakan larutan basa

dan terkesan licin.

Gambar 3.4. Larutan NaOH

37

3.1.2. Penyiapan Alat.

a. Timbangan digital

Timbangan yang digunakan untuk menimbang serat dan

polyester adalah timbangan digital.

Gambar 3.5. Timbangan Digital.

b. Alat Uji Kadar Air.

Alat uji kadar air ini digunakan untuk mengukur kadar air

serat rami, dengan ketentuan kadar air 10%.

Gambar 3.6. wood moisture meter.

38

c. Cetakan Benda Uji

Cetakan yang digunakan terbuat dari kaca bening dengan

ketebalan 3mm, 4mm, dan 5 mm.

Gambar 3.7. Cetakan untuk benda uji.

d. Alat Pengepres Cetakan.

Untuk penekan digunakan alat pres mold

Gambar 3.8. Alat Pengepres Cetakan.

e. Alat Bantu lain

39

Alat Bantu lain yang digunakan, meliputi : sendok, cutter,

gunting, kuas, pisau, spidol, kit mobil, penggaris, dan gelas ukur.

Gambar 3.9. Alat bantu lain.

f. Grenda pemotong dan amplas

Grenda pemotong digunakan untuk memotong komposit

menjadi spesimen dan untuk menghaluskan permukaan bekas

potongan digunakan amplas.

40

3.2. Diagram Alir

Gambar 3.10. Diagram alir penelitian

Hasil

Analisa dan Pembahasan

Kesimpulan

Selesai

Uji tarik (ASTM D638-02)

Uji impak (ASTM D256-00)

Pengujian :

Pembuatan Spesimen sesuai Standart

Foto Makro Uji bending (ASTM D790-02)

Pembuatan Komposit Skin dengan serat acak (Mat Fiber Composit) dengan metode pres

mold

Serat Rami Dengan Vf 20%, 30%, 40%, 50%

Resin polyeter dan MEKPO 1%

Pembuatan cetakan dengan variasi ketebalan 1mm, 2mm,

3mm, 4mm, dan 5mm,

Mulai

Study Literatur dan Survey Lapangan

Persiapan

Bahan

Perlakuan Alkali

41

3.2.1. Survey Lapangan dan Study Literature.

Proses yang dilakukan pada penelitian ini adalah dengan

mengumpulkan data awal sebagai study literature. Study literature

bertujuan untuk mengenal masalah yang dihadapi, serta untuk

menyusun rencana kerja yang akan dilakukan. Pada studi awal

dilakukan langkah-langkah seperti survey dilapangan terhadap hal-hal

yang berhubungan dengan penelitian yang akan dilakukan serta

mengambil data-data penelitian yang sudah ada untuk dijadikan

sebagai pembanding terhadap hasil pengujian yang akan dianalisa.

Selain itu pada proses ini juga dilakukan perancangan alat pres-mold

yang digunakan untuk membuat spesimen yang sesuai dengan karakter

matrik yang dipakai.

3.2.2. Penyiapan bahan

Mengumpulkan semua bahan-bahan yang akan digunakan

dalam proses pembuatan komposit skin. Diantaranya yaitu serat rami,

larutan NaOH dan polyester beserta katalis.

3.2.3. Pembuatan Komposit

Proses pembuatan komposit serat rami dengan matrik polyester

adalah sebagai berikut:

42

1. Penyiapan serat rami, untuk serat rami dicuci dahulu, kemudian

dimasukkan kedalam larutan NaOH 5% selama 2jam, 4jam, 6jam

dan 8jam, lalu dikeringkan sampai kadar air mecapai 10%.

2. Setelah serat kering kemudian dilakukan proses pembuatan serat

secara acak sesuai bentuk cetakan.

3. Pembuatan cetakan

Untuk pengujian bending dan impak menggunakan kaca dengan

ketebalan 3mm, 4mm, dan 5mm.

Tebal

komposit

Ukuran cetakan Daerah pencetakan

3mm 230 x 205 x 16mm 150 x 125 x 3mm

4mm 230 x 205 x 17mm 150 x 125 x 4mm

5mm 230 x 205 x 18mm 150 x 125 x 5mm

Untuk tebal komposit 1mm menggunakan tebal cetakan 5mm

ditambahkan kaca 4mm kedalam cetakan untuk mengurangi volume

cetakan dan penambahan kaca 3mm kedalam cetakan untuk tebal

komposit 2mm.

4. Pengolesan wax mold release atau kit motor pada cetakan untuk

memudahkan pengambilan benda uji dari cetakan setelah

mengalami proses pengeringan.

5. Resin polyester dicampur dengan katalis untuk membantu proses

pengeringan. Katalis yang digunakan sebanyak 1% dari banyaknya

resin poliester yang digunakan.

43

6. Penuangan campuran resin sebagian dari takaran kedalam cetakan,

dilanjutkan penempatan serat rami yang telah disusun secara acak,

kemudian diatas serat dituang kembali sisa campuran resin pada

gelas takaran kedalam cetakan sambil dipukul-pukul dengan sendok

biar campuran resin masuk kedalam serat yang kemudian ditutup

dengan kaca dan ditekan dengan dengan alat penekan.

7. Penutupan dengan menggunakan kaca yang bertujuan agar void

yang kelihatan dapat diminimalkan jumlahnya yang kemudian

dilakukan pengepresan dengan menggunakan alat pengepres.

8. Proses pengeringan dilakukan sampai benar-benar kering yaitu 5 –

10 jam dan apabila masih belum benar-benar kering maka proses

pengeringan dapat dilakukan lebih lama

9. Proses pengambilan komposit dari cetakan yaitu menggunakan

pisau ataupun cutter.

10. Benda uji komposit siap untuk dipotong menjadi spesimen benda uji.

Berikut beberapa gambar dari Komposit serat Rami dengan

menggunakan matrik resin polyester.

44

Gambar 3.11. Hasil cetakan komposit serat Rami dengan

matrik polyester

Gambar 3.12. Spesimen uji tarik komposit serat rami

Gambar 3.13. Spesimen uji bending komposit serat rami

45

Gambar 3.14. Spesimen uji impak komposit serat rami.

3.2.4. Pengujian Komposit

Pengujian yang dilakukan pada penelitian ini antara lain

pengujian bending, pengujian impak,dan foto makro.

3.2.4.1. Pengujian bending.

Material komposit mempunyai sifat tekan yang lebih baik

dibanding sifat tariknya. Kekuatan tarik di pengaruhi oleh ikatan

molekul material penyusunnya. Pada pengujian bending ini

bertujuan untuk mengetahui besarnya kekuatan lentur dari

material komposit. Pengujian dilakukan dengan jalan memberi

beban lentur secara perlahan-lahan sampai spesimen mencapai

titik lelah. Pada perlakuan uji bending bagian atas spesimen

mengalami proses penekanan dan bagian bawah mengalami

proses tarik sehingga akibatnya spesimen mengalami patah

bagian bawah karena tidak mampu menahan tegangan tarik.

Spesimen uji bending dibuat sesuai standar ASTM D790 – 02.

46

Langkah-langkah pengujian bending yaitu :

1. Mempersiapkan benda uji.

2. Menentukan titik tumpuan dan titik tengah benda uji dengan

memberi tanda garis.

3. Menentukan besarnya beban yang digunakan.

4. Meletakkan spesimen pada meja mesin pengujian bending

dengan jarak tumpuan dan titik tengah yang telah ditentukan.

5. Putar handle sampai beban menyentuh benda uji dan

manometer indikator menunjukkan angka nol.

6. Tentukan putaran jarum penentu waktu untuk pencatatan

beban selanjutnya.

7. Catat hasil pengujian bending setiap putaran yang telah

ditentukan.

8. Menentukan harga bending.

Gambar 3.15. Dimensi pengujian bending Standar ASTM D 790-02

47

Gambar 3.16. Mesin Pengujian Bending

(Laboratorium Material Teknik UMS)

3.2.4.2. Pengujian impak

Pada uji impak charpy kita mengukur energi yang diserap

untuk mematahkan benda uji. Setelah benda uji patah, bandul

berayun kembali. Makin besar energi yang diserap makin rendah

ayunan kembali dari bandul. Energi patahan yang diserap

biasanya dinyatakan dalam satuan joule.

Prinsip dari pengujian impak ini adalah apabila benda uji

diberi beban kejut, maka benda akan mengalami proses

penyerapan energi sehingga terjadi deformasi plastis yang

mengakibatkan patah.

48

Untuk mengetahui ketahanan benda terhadap keadaan

patah, maka digunakan metode pengujian impak charphy.

Langkah-langkah pengujian impak :

1. Mengukur dimensi dari skin yaitu tebal, lebar, dan

panjangnya, kemudian memberikan no spesimen pada

skin yang akan diuji.

2. Mengangkat beban palu.

3. Meletakkan spesimen pada batang uji atau tumpuan dengan

bantuan penjepit.

4. Melepaskan palu atau bandul dengan cara menekan tombol

dan menarik handel-nya.

5. Palu akan jatuh dan memukul spesimen secara otomatis.

6. Catat energi serap yang ditunjukkan oleh jarum pada alat uji

impak.

7. Hitung harga impak.

Keretakan akibat uji impak ada tiga bentuk yaitu :

1. Patahan getas

Permukaan patahan terlihat rata dan mengkilap, kalau

potongan-potongannya kita sambungkan lagi, ternyata

keretakannya tidak disertai dengan deformasinya bahan.

Patahan jenis ini mempunyai harga impak yang rendah.

49

2. Patahan liat.

Permukaan patahan ini tidak rata, nampak seperti buram dan

berserat, tipe ini mempunyai harga impak yang tinggi.

3. Patahan campuran.

Patahan yang terjadi merupakan campuran dari patahan

getas dan patahan liat. Patahan ini paling banyak terjadi.

Gambar 3.17. Mesin pengujian impak charpy

( Laboratorium Material Teknik Mesin UMS )

Gambar 3.18. Dimensi impak ASTM D 5942-96

50

Prinsip dari pengujian impak ini adalah apabila benda uji

diberi beban kejut, maka benda akan mengalami proses

penyerapan energi sehingga terjadi deformasi plastis yang

mengakibatkan perpatahan.

3.2.4.2. Pengujian Tarik

Pengujian tarik dilakukan untuk mengetahui besarnya

kekuatan tarik dari bahan komposit. Pengujian dilakukan dengan

mesin uji “Universal Testing Machine” buatan jepang. Spesimen

pengujian tarik di bentuk menurut standar ASTM D 638-03 tipe 4

yang ditunjukkan pada gambar berikut:

G

Gambar 3.19. Dimensi benda pengujian tarik

Dimana:

Lo : panjang paralel (mm)

b : Lebar (mm)

Z : Panjang total spesimen (mm)

Z=115mm

Lo=33mm

B=6mm

R=14mm

51

d : Tebal (mm)

A : Lebar pegangan (mm)

Langkah-langkah pengujian tarik dalam penelitian ini adalah

sebagai berikut:

1. Ukur panjang uji dan penempang uji sebelum diuji.

2. Siapkan mesin uji tarik yang digunakan.

3. Masukkan dan seting kertas milimeter-blok diatas mesin plotter.

4. Pasang spesimen tarik dan pastikan terjepit dengan betul.

5. Jalankan mesin uji tarik.

6. Setelah patah, hentikan proses penarikan secepatnya, catat gaya

tarik maksimum dan pertambahan panjangnya.

7. Ambil hasil rekaman mesin plotter dari proses penarikan yang

tertuang dalam kertas milimeter-blok.

Gambar 3.20. Mesin pengujian tarik

( Laboratorium Material Teknik Mesin UMS )

52

3.2.4.3. Foto Patahan Makro

Pengambilan foto makro bertujuan untuk mengetahui

jenis/bentuk patahan dan pola kegagalan yang terjadi pada

spesimen komposit akibat pengujian bending dan impak. Objek

yang diambil dari penampang patahan dan dari samping untuk

pengujian impak sedangkan untuk bending diambil dari samping

benda uji.

Adapun langkah-langkah pengambilan foto patahan makro

adalah sebagai berikut:

1. Nyalakan lampu sebagai sumber cahaya.

2. Letakkan spesimen pada “Stage Plate”.atau meja objek.

3. Memasang lensa repro pada kamera dan atur perbesaran

yang diinginkan.

4. Lihat gambar pada “LCD” yaitu pada layar kamera.

5. Fokuskan gambar.

6. Untuk melakukan pemotretan:

a. Dilakukan dengan kamera digital Nikon E3500, 7.1 Mega

pixel.

b. Tekan “Expose” untuk melakukan pemotretan

7. Melihat hasil pemotretan.

53

BAB IV

HASIL PENELITIAN DAN PEMBAHASAN

4.1. Pengujian Bending

4.1.1. Data Hasil Pengujian Bending Alkali 2 Jam.

Table 4.1.1.1. Data hasil pengujian bending rata-rata pada tebal 1mm

Table 4.1.1.2. Data hasil pengujian bending rata-rata pada tebal 2mm

Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata

(Nmm) (MPa) (mm) (MPa) (Nmm2)

Fraksi

volume

20%

946,775 100,9908 1,852 4069,78937 40217,455

Fraksi

volume

30%

593,575 34,4637 1,894 989,51153 23763,342

Fraksi

volume

40%

537,350 33,8882 1,028 1833,96408 39530,369

Fraksi

volume

50%

1838,825 74,4255 1,943 1859,34807 ,76933,570

Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

213,424 55,97055 2,376 1884,05211 4839,83537

Fraksi

volume

30%

228,642 38,70191 3,545 700,82351 3499,27007

Fraksi

volume

40%

205,570 18,24936 4,505 199,97964 2559,10614

Fraksi

volume

50%

599,567 74,30054 1,396 2995,64239 23148,5484

53

54

Tabel 4.1.1.3. Data hasil pengujian bending rata-rata pada tebal 3mm

Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

1198,458 51,4811 2,643 2848,62956 101211,,969

Fraksi

volume

30%

1567,083 39,6608 2,213 1806,63456 151084,496

Fraksi

volume

40%

4241,833 143,9594 2,259 7253,41067 391090,483

Fraksi

volume

50%

1760,166 41,6608 2,831 1300,21282 123368,528


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

2792,725 67,7365 7,021 1586,66787 139886,556

Fraksi

volume

30%

2983,121 63,8266 6,818 1427,32660 155910,587

Fraksi

volume

40%

1963,054 29,0413 18,968 208,36962 38846,421

Fraksi

volume

50%

6205,170 111,8048 4,830 3091,58165 441537,555

55


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending Rata-

rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

4142,133 58,8363 8,797 1327,05801 253517,2649

Fraksi

volume

30%

3790,933 63,5019 12,364 1045,49661 164533,6752

Fraksi

volume

40%

4904,540 67,4877 4,541 2797,49988 586992,0176

Fraksi

volume

50%

6257,060 60,3870 4,433 2175,88513 789882,4878

Gambar 4.1. Grafik hubungan momen bending rata-rata dengan fraksi

volume terhadap tebal komposit.

599,567

1838,831760,17

6205,176257,06

0

1000

2000

3000

4000

5000

6000

7000

0% 10% 20% 30% 40% 50% 60%

Mo

me

n b

en

din

g ra

ta-r

ata

(mm

4)

Fraksi volume(%)

Tebal 1mm Tebal 2mm Tebal 3mm Tebal 4mm Tebal 5mm

56

Gambar 4.2. Grafik hubungan tegangan bending rata-rata dengan

fraksi volume terhadap tebal komposit.

Gambar 4.3. Grafik hubungan defleksi bending rata-rata dengan


74,3005474,42552

41,66083

111,8048

60,38704

0

20

40

60

80

100

120

140

160

0% 10% 20% 30% 40% 50% 60%

Tega

nga

n b

en

din

g ra

ta-r

ata

(MP

a)

Fraksi volume(%)


1,3961,9432,831

4,834,433

0

2

4

6

8

10

12

14

16

18

20

0% 10% 20% 30% 40% 50% 60%

De

fle

ksi b

en

din

g ra

ta-r

ata

(mm

)

Fraksi volume(%)


57

Gambar 4.4. Grafik hubungan modulus elastisitas bending rata-rata

dengan fraksi volume terhadap tebal komposit.

Gambar 4.5. Grafik hubungan kekakuan bending rata-rata dengan


2995,642

1859,3481300,213

3091,582

2175,885

0

1000

2000

3000

4000

5000

6000

7000

8000

0% 10% 20% 30% 40% 50% 60%

Mo

du

lus

ela

stis

itas

be

nd

ing

rata

-rat

a(M

Pa)

Fraksi volume(%)


23148,548476933,57076123368,5286

441537,555

789882,4878

0

100000

200000

300000

400000

500000

600000

700000

800000

900000

0% 10% 20% 30% 40% 50% 60%

Ke

kaku

an b

en

din

g ra

ta-r

ata

(N/m

m2 )

Fraksi volume(%)


58

4.1.1. Pembahasan Pengujian Bending Dengan Perlakuan

Alkali 2 jam.

Dari data-data yang telah diperoleh dapat disimpulkan

bahwa harga kekuatan bending komposit serat acak rami pada

spesimen tebal 1mm Vf 50% (74,30054 MPa), lebih besar dari

Vf 20%, Vf 30%, Vf 40% yaitu 55,97055 MPa, 38,70191 MPa,

18,24936 MPa. Pada spesimen tebal 2mm Vf 20% (100,9908

MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50% yaitu 34,4637

MPa, 33,8882 MPa, 74,4255 MPa. Pada spesimen tebal 3mm

Vf 40% (143,9594 MPa), lebih besar dari Vf 20%, Vf 30%, Vf

50% yaitu 51,4811 MPa, 39,6608 MPa, 41,6608 MPa. Pada





MPa, 63,5019 MPa, 60,3870 MPa. Dari data-data yang telah

diperoleh menunjukkan harga kekuatan bending optimal yaitu

pada spesimen tebal 3mm Vf 40% sebesar 143,9594 MPa, ini

dikarenakan momen material komposit pada variasi ini memiliki

harga yang tertinggi.

Sedangkan modulus elastisitas rata-rata tertinggi

komposit serat rami acak pada spesimen tebal 1mm Vf 50%

(2995,64239 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%

59

yaitu 1884,05211 MPa, 700,823517 MPa, 199,97964 MPa.

Pada spesimen tebal 2mm Vf 20% (4069,78937 MPa), lebih

besar dari Vf 30%, Vf 40%, Vf 50% yaitu 989,51153 MPa,

1833,96408 MPa, 1859,34807 MPa. Pada spesimen tebal 3mm


50% yaitu 2848,62956 MPa, 1806,63456 MPa, 1300,21282

MPa. Pada spesimen tebal 4mm Vf 50% (3091,58165 MPa),

lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 1586,66787 MPa,



50% yaitu 1327,05801 MPa, 1045,49661 MPa, 2175,88513

MPa. Dari data-data yang telah diperoleh harga modulus

elastisitas bending optimal yaitu pada spesimen tebal 3mm Vf

40% sebesar 7253,41067 MPa.

60


Table 4.6. Data hasil pengujian bending rata-rata pada tebal 1mm


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

239,564 62,8666 2,256 2252,5189 5770,58849

Fraksi

volume

30%

193,442 33,2409 2,233 960,0569 4663,31747

Fraksi

volume

40%

391,138 34,5953 2,732 624,5529 8100,30505

Fraksi

volume

50%

452,966 55,8130 4,093 887,0887 6897,15191

Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume 20% 574,975 61,0075 2,848 1576,3669 15656,5791

Fraksi

volume 30% 641,9 37,2716 2,671 797,9732 19438,07467

Fraksi

volume 40% 1877,15 119,5723 1,696 3814,1518 82203,3813

Fraksi

volume 50% 2455,6 99,3298 2,052 2160,0695 89834,90114

61

Tabel 4.8. Data hasil pengujian bending rata-rata pada tebal 3mm

Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

1364,750 57,9439 2,591 3611,6808 130378,4937

Fraksi

volume

30%

1293,208 34,0783 1,270 2593,4177 215638,1473

Fraksi

volume

40%

1372,25 46,0235 2,213 2402,9037 130896,9267

Fraksi

volume

50%

2862,916 67,0127 1,371 4896,9335 470495,5037


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-

rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

2532,467 36,0286 6,367 1153,0738 216760,7534

Fraksi

volume

30%

4201,533 70,1437 7,012 2111,1889 338571,7448

Fraksi

volume

40%

6625,733 64,2087 2,911 3707,22952 1320731,722

Fraksi

volume

50%

7748,733 106,4359 4,192 4687,609145 992668,6561

62


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume 20% 1997,775 48,0787 3,522 2373,4008 209108,7464

Fraksi

volume 30% 3800,1166 67,616031 4,168 2255,9084 324737,0704

Fraksi

volume 40% 4560,075 67,5851 3,282 2802,1701 513118,2639

Fraksi

volume 50% 4121 88,12637 2,719 5053,48233 550364,9035

Gambar 4.6. Grafik hubungan momen bending rata-rata

dengan fraksi volume terhadap tebal komposi

452,966

2455,62862,917

4121

7748,73

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0% 10% 20% 30% 40% 50% 60%

Mo

me

n b

en

din

g ra

ta-r

ata

(mm

4)

Fraksi volume(%)


63

Gambar 4.7. Grafik hubungan tegangan bending rata-rata dengan

fraksi volume terhadap tebal komposit



55,813064

99,329893

67,01279282

88,1263793

106,4359297

0

20

40

60

80

100

120

140

0% 10% 20% 30% 40% 50% 60%

Tega

nga

n b

en

din

g ra

ta-r

ata

(MP

a)

Fraksi volume(%)


4,093

2,0521,371

2,719

4,192

0

1

2

3

4

5

6

7

8

0% 10% 20% 30% 40% 50% 60%

De

fle

ksi b

en

din

g ra

ta-r

ata

(mm

)

Fraksi volume(%)


64

Gambar 4.9. Grafik hubungan modulus elastisitas bending rata-rata




887,088

2160,0695

4896,9335875053,482334687,609145

0

1000

2000

3000

4000

5000

6000

0% 10% 20% 30% 40% 50% 60%Mo

du

lus

ela

stis

itas

be

nd

ing

rata

-rat

a(M

Pa)

Fraksi volume(%)


6897,1519189834,90114

470495,5037550364,9035

992668,6561

0

200000

400000

600000

800000

1000000

1200000

1400000

0% 10% 20% 30% 40% 50% 60%

Ke

kaku

an b

en

din

g ra

ta-r

ata

(N/m

m2 )

Fraksi volume(%)


65

4.1.2.1 Pembahasan Pengujian Bending Dengan

Perlakuan Alkali 4 Jam



spesimen tebal 1mm Vf 20% (62,8666 MPa), lebih besar dari Vf

30%, Vf 40%, Vf 50% yaitu 33,2409 MPa, 34,5953 MPa,



MPa, 37,2716 MPa, 99,3298 MPa. Pada spesimen tebal 3mm

Vf 50% (67,0127 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%

yaitu 57,9439 MPa, 34,0783 MPa, 46,0235 MPa. Pada


20%, Vf 30%, Vf 40% yaitu 48,0787 MPa, 67,616031MPa,

67,585148 MPa. Pada spesimen tebal 5mm Vf 50%


yaitu 36,0286 MPa, 70,1437 MPa, 64,20870 MPa. Dari data-

data yang telah diperoleh menunjukkan harga kekuatan bending

optimal yaitu pada spesimen tebal 2mm Vf 40% sebesar

119,5723 MPa, ini dikarenakan momen material komposit pada

variasi ini memiliki harga yang tertinggi.



(2252,5189 MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50% yaitu

66

960,0569 MPa, 624,5529 MPa, 887,0887 MPa. Pada spesimen

tebal 2mm Vf 40% (3814,1518 MPa), lebih besar dari Vf 20%, Vf

30%, Vf 50% yaitu 1576,3669 MPa, 797,9732 MPa, 2160,0695

MPa. Pada spesimen tebal 3mm Vf 50% (4896,9335 MPa), lebih




40% yaitu 2373,4008 MPa, 2255,90842 MPa, 2802,1701 MPa.

Pada spesimen tebal 5mm Vf 50% (4687,60914 MPa), lebih


2111,1889 MPa, 3707,22952 MPa. Dari data-data yang telah

diperoleh harga modulus elastisitas bending optimal yaitu pada

spesimen tebal 4mm Vf 50% sebesar 5053,48233 MPa.

67




Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-

rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi volume

20% 803,575 85,61409 3,5873 1874,33529 18814,76883

Fraksi volume

30% 2072,55 120,4369 1,27 5114,59448 123254,4682

Fraksi volume

40% 1577,225 99,39187 1,219 4654,64397 100316,1956

Fraksi volume

50% 2519,5 101,85879 1,4343 3292,70595 136747,1912

Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

132,652 35,0543 3,706 782,0684 2018,934159

Fraksi

volume

30%

180,1918 30,3453 5,029 396,2280 1942,629864

Fraksi

volume

40%

517,8001 45,8119 3,350 647,4459 8351,128725

Fraksi

volume

50%

417,9993 52,1525 2,426 1193,8059 9225,10121

68


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

1470,833 64,5698 2,984 3048,1183 107484,7506

Fraksi

volume

30%

1428,5416 36,2652 2,973 1187,4769 99578,8228

Fraksi

volume

40%

3560,1666 123,2598 2,771 5092,3261 267131,7309

Fraksi

volume

50%

2293,5416 53,68071 1,954 2623,5904 244927,5693


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume 20% 2271,208 55,28018 2,863 3312,1658 293203,8556

Fraksi

volume 30% 3111,983 66,56700 3,859 2626,6752 285747,1332

Fraksi

volume 40% 2740,995 40,70235 4,292 1243,2007 227115,3075

Fraksi

volume 50% 4618,3041 81,56316 3,349 3606,1574 533366,1163

69


Jenis

Komposit

Momen

Bending

Rata-rata

Tegangan

Bending

Rata-rata

Defleksi

Bending

Rata-rata

Modulus

Elastisitas

Bending

Rata-rata

Kekakuan

Bending

Rata-rata


Fraksi

volume

20%

2093,733 30,67423 9,185 660,8281 126236,8127

Fraksi

volume

30%

3393,2 56,91016 9,183 1297,2945 203167,9703

Fraksi

volume

40%

4394,533 60,52086 7,545 1513,6803 316967,853

Fraksi

volume

50%

7243,866 70,23699 5,276 2034,2484 731965,123


dengan fraksi volume terhadap tebal komposit

417,9993333

2519,52293,541667

4618,304167

7243,8666

0

1000

2000

3000

4000

5000

6000

7000

8000

0% 10% 20% 30% 40% 50% 60%

Mo

me

n b

en

din

g ra

ta-r

ata

(mm

4 )

Fraksi volume(%)


70

Gambar 4.12. Grafik hubungan tegangan bending rata-rata




52,15256141

101,8587993

53,68071386

81,5631650970,23699981

0

20

40

60

80

100

120

140

0% 10% 20% 30% 40% 50% 60%

Tega

nga

n b

en

din

g ra

ta-r

ata

(MP

a)

Fraksi volume(%)


2,4261,4341,954

3,349

5,276

0

2

4

6

8

10

0% 10% 20% 30% 40% 50% 60%

De

fle

ksi b

en

din

g ra

ta-r

ata

(mm

)

Fraksi volume(%)


71

Gambar 4.14. Grafik hubungan modulus elastisitas bending

rata-rata dengan fraksi volume terhadap tebal komposit



1193,805941

3292,705955

2623,590426

3606,157415

2034,248473

0

1000

2000

3000

4000

5000

6000

0% 10% 20% 30% 40% 50% 60%

Mo

du

lus

ela

stis

itas

be

nd

ing

rata

-rat

a(M

Pa)

Fraksi volume(%)


9225,10121

136747,1912

244927,5693

533366,1163

731965,1235

0

100000

200000

300000

400000

500000

600000

700000

800000

0% 10% 20% 30% 40% 50% 60%

Ke

kaku

an b

en

din

g ra

ta-r

ata

(N/m

m2)

Fraksi volume(%)


72






20%, Vf 30%, Vf 40% yaitu 35,0543 MPa, 30,3453 MPa,

45,8119 MPa. Pada spesimen tebal 2mm Vf 30% (120,4369),


99,39187 MPa, 101,85879 MPa. Pada spesimen tebal 3mm Vf

40% (123,2598 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50%














73

782,0684 MPa, 396,2280 MPa, 647,4459 MPa. Pada spesimen

tebal 2mm Vf 30% (5114,59448 MPa), lebih besar dari Vf 20%,

Vf 40%, Vf 50% yaitu 1874,33529 MPa, 4654,64397 MPa,

3292,70595 MPa. Pada spesimen tebal 3mm Vf 40%


3048,1183 MPa, 1187,4769 MPa, 2623,5904 MPa. Pada





MPa, 1297,2945 MPa, 1513,6803 MPa. Dari data-data yang

telah diperoleh harga modulus elastisitas bending optimal yaitu

pada spesimen tebal 2mm Vf 30% sebesar 5114,59448 MPa.

74




Jenis Komposit

Momen Bending Rata-rata

Tegangan Bending Rata-rata

Defleksi Bending

Rata-rata

Modulus Elastisitas Bending Rata-rata

Kekakuan Bending Rata-rata


Fraksi volume

20% 575,150 61,39330 2,354 1885,20806 18728,78645

Fraksi volume

30% 686,125 40,02084 1,961 1133,19314 27570,30099

Fraksi volume

40% 1428,825 89,39942 1,505 3267,25884 71414,83031

Fraksi volume

50% 2004,075 80,97404 2,190 1638,91647 68252,33662

Jenis Komposit

Momen Bending

Rata-rata


Defleksi Bending

Rata-rata




Fraksi volume

20% 130,662 34,32639 4,125 724,95737 1846,08538

Fraksi volume

30% 281,029 49,80113 5,539 567,14517 2696,24404

Fraksi volume

40% 385,953 34,19423 3,308 505,05016 6476,82875

Fraksi volume

50% 632,544 78,03006 2,102 2093,29932 16217,37964

75


Jenis Komposit



Defleksi Bending

Rata-rata




Fraksi volume

20% 577,875 27,35307 1,780 2022,62093 67304,49059

Fraksi volume

30% 1257,666 32,79411 2,296 1390,64183 118680,8508

Fraksi volume

40% 2620,166 86,76242 3,297 3176,77790 179245,5071

Fraksi volume

50% 4282,166 102,10968 1,736 5474,08931 507225,0836


Jenis Komposit



Defleksi Bending

Rata-rata




Fraksi volume

20% 1889,442 45,44886 3,595 2121,48961 191138,151

Fraksi volume

30% 2755,837 58,92963 6,045 1506,94289 164344,4337

Fraksi volume

40% 3723,579 55,59110 4,449 1635,84638 299174,4884

Fraksi volume

50% 4956,520 87,83150 4,289 2907,42209 416628,8935

76


Jenis Komposit



Defleksi Bending

Rata-rata




Fraksi volume

20% 2203,067 31,59097 4,467 1423,26882 268821,8254

Fraksi volume

30% 3671,933 61,47096 7,837 1602,08804 253191,2614

Fraksi volume

40% 5587,133 76,34464 5,047 2757,31646 581851,329

Fraksi volume

50% 4596,533 44,66811 5,184 1313,34294 470505,990



632,5447

2004,075

4282,167

4956,5214596,533

0

1000

2000

3000

4000

5000

6000

0% 10% 20% 30% 40% 50% 60%

Mo

me

n b

en

din

g ra

ta-r

ata

(mm

4)

Fraksi volume(%)


77

Gambar 4.17. Grafik hubungan tegangan bending rata-rata


Gambar 4.18. Grafik hubungan defleksi bending rata-rata


78,03006580,9740418

102,109681

87,8315065

44,6681165

0

20

40

60

80

100

120

0% 10% 20% 30% 40% 50% 60%

Tega

nga

n b

en

din

g ra

ta-r

ata

(MP

a)

Fraksi volume(%)


2,1022,191,736

4,289

5,184

0

1

2

3

4

5

6

7

8

9

0% 10% 20% 30% 40% 50% 60%

De

fle

ksi b

en

din

g ra

ta-r

ata

(mm

)

Fraksi volume(%)


78

Gambar 4.19. Grafik hubungan modulus elastisitas bending

rata-rata dengan fraksi volume terhadap tebal komposit.

Gambar 4.20. Grafik hubungan kekakuan bending rata-rata


2093,299331638,91647

5474,08931

2907,4221

1313,34295

0

1000

2000

3000

4000

5000

6000

0% 10% 20% 30% 40% 50% 60%

Mo

du

lus

ela

stis

itas

be

nd

ing

rata

-rat

a(M

Pa)

Fraksi volume(%)


16217,3796468252,33662

507225,0836

416628,8935470505,9907

0

100000

200000

300000

400000

500000

600000

700000

0% 10% 20% 30% 40% 50% 60%

Ke

kaku

an b

en

din

g ra

ta-r

ata

(N/m

m2)

Fraksi volume(%)


79







34,19423 MPa. Pada spesimen tebal 2mm Vf 40% (89,39942),


40,02084 MPa, 80,97404 MPa. Pada spesimen tebal 3mm Vf

50% (102,10968 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%














80


spesimen tebal 2mm Vf 40% (3267,25884 MPa), lebih besar

dari Vf 20%, Vf 30%, Vf 50% yaitu 1885,20806 MPa,



40% yaitu 2022,62093 MPa, 1390,64183 MPa, 3176,77790

MPa. Pada spesimen tebal 4mm Vf 50% (2907,42209 MPa),




50% yaitu 1423,26882 MPa, 1602,08804 MPa, 1313,34294

MPa. Dari data-data yang telah diperoleh harga modulus

elastisitas bending optimal yaitu pada spesimen tebal 3mm Vf

50% sebesar 5474,089311 MPa.

81

4.2. Pengujian Tarik

4.2.1 Data Hasil Pengujian Tarik Rata-rata Pada Alkali 2 Jam

Tabel 4.21. Hasil Data Pengujian Tarik Alkali 2 Jam

Spesimen Kekuatan Tarik Rata-Rata Modulus Elastisitas Rata-Rata

20 % T1 0.662 0.797

30 % T1 0.772 0.850

40 % T1 0.906 1.174

50 % T1 1.506 1.747

20 % T2 1.348 3.297

30 % T2 1.994 4.060

40 % T2 2.523 4.875

50 % T2 3.192 5.565

20 % T3 2.193 5.924

30 % T3 3.032 6.756

40 % T3 4.686 28.560

50 % T3 5.941 9.449

20 % T4 4.353 5.208

30 % T4 3.714 5.899

40 % T4 6.018 4.782

50 % T4 11.710 9.069

20 % T5 8.399 5.884

30 % T5 8.377 5.462

40 % T5 9.423 6.341

50 % T5 12.644 8.731

82

Gambar 4.21. Grafik hubungan modulus elastisitas tarik rata-

rata dengan fraksi volume terhadap tebal komposit

Gambar 4.22. Grafik hubungan kekuatan tarik rata-rata dengan


1,747

5,5659,069

8,731

0

5

10

15

20

25

30

0 10 20 30 40 50 60

Mo

du

lus

Elas

tisi

tas

Tar

ik R

ata

-rat

a(M

Pa)

Fraksi Volume(%)

Tebal 1 mm Tebal 2 mm Tebal 3 mm Tebal 4 mm Tebal 5 mm

1,506

3,192

5,941

11,71012,644

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60

Ke

kuat

an T

arik

Rat

a-r

ata

(MP

a)

Fraksi Volume(%)


83

4.2.1.1 Pembahasan Pengujian Tarik Alkali 2 Jam

Dari hasil pengujian tarik didapatkan harga yang paling

optimal pada tebal 5mm Vf 50% yaitu sebesar 12,644 MPa,

sedangkan yang terendah adalah komposit serat rami dengan Vf

20% pada tebal 1mm yang mempunyai harga tarik rata- rata 0,662

MPa. Hal ini dipengaruhi oleh fraksi volume dan ketebalan

spesimen, semakin tebal dan fraksi meningkat maka harga

kekuatan tarik meningkat.

Sedangkan untuk Modulus elastisitas tertinggi pada tebal

3mm fraksi volume 40% yaitu sebesar 28,560 MPa,sedangkan

terendah adalah pada spesimen fraksi volume 20% ketebalan 1mm

yaitu 0,797 MPa.

84




20 % T1 0,798 0,878

30 % T1 0,755 0,956

40 % T1 1,868 1,498

50 % T1 1,483 2,025

20 % T2 1,806 3,308

30 % T2 1,663 1,563

40 % T2 3,354 4,921

50 % T2 4,769 7,103

20 % T3 2,845 6,928

30 % T3 3,787 5,942

40 % T3 3,155 6,049

50 % T3 7,613 10,019

20 % T4 4,680 8,275

30 % T4 4,972 7,385

40 % T4 4,852 9,222

50 % T4 6,983 8,919

20 % T5 2,992 7,659

30 % T5 4,530 9,801

40 % T5 4,988 8,909

50 % T5 9,581 12,244

85





2,025

7,1036,049

10,0198,919

12,244

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60

Mo

du

lus

Elas

tisi

tas

Tar

ik R

ata

-rat

a(M

Pa)

Fraksi Volume(%)


1,483

4,769

7,6136,983

9,581

0

2

4

6

8

10

12

0 10 20 30 40 50 60

Ke

kuat

an T

arik

Rat

a-r

ata

(MP

a)

Fraksi Volume(%)


86






MPa.




yaitu 0,878 MPa.

87


Tabel 4.23. Hasil Data Pengujian Tarik Alkali 6 Jam.


20 % T1 0,601 0,886

30 % T1 1,059 1,128

40 % T1 1,388 1,568

50 % T1 2,352 3,096

20 % T2 1,856 2,700

30 % T2 1,971 5,536

40 % T2 4,824 7,293

50 % T2 5,164 5,205

20 % T3 2,738 5,420

30 % T3 3,350 7,040

40 % T3 4,920 6,533

50 % T3 6,740 9,554

20 % T4 3,402 7,451

30 % T4 5,379 9,314

40 % T4 6,604 8,290

50 % T4 5,357 8,917

20 % T5 4,270 8,504

30 % T5 5,858 9,652

40 % T5 6,465 7,410

50 % T5 10,091 11,638

88





3,096

5,205

9,5548,917

11,638

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60Mo

du

lus

Elas

tisi

tas

Tar

ik R

ata

-rat

a(M

Pa)

Fraksi Volume(%)


2,352

5,164

6,740

5,357

10,091

0

2

4

6

8

10

12

0 10 20 30 40 50 60

Ke

kuat

an T

arik

Rat

a-r

ata

(MP

a)

Fraksi Volume(%)


89






MPa.




yaitu 0,886 MPa.

90




20 % T1 0,604

0,895

30 % T1 1,222 1,908

40 % T1 1,132 1,213

50 % T1 1,788 3,309

20 % T2 1,448 2,825

30 % T2 2,262 4,441

40 % T2 3,663 6,784

50 % T2 3,785 6,919

20 % T3 2,684 5,557

30 % T3 3,307 5,657

40 % T3 4,272 6,898

50 % T3 7,751 9,318

20 % T4 3,323 7,485

30 % T4 4,131 7,596

40 % T4 5,713 10,160

50 % T4 10,062 8,705

20 % T5 5,679 12,173

30 % T5 6,093 11,420

40 % T5 7,931 11,122

50 % T5 7,174 10,558

91





3,309

6,919

9,3188,705

10,558

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60

Mo

du

lus

Elas

tisi

tas

Tar

ik R

ata

-rat

a(M

Pa)

Fraksi Volume(%)


1,788

3,785

7,751

10,062

7,174

0

2

4

6

8

10

12

0 10 20 30 40 50 60

Ke

kuat

an T

arik

Rat

a-r

ata

(MP

a)

Fraksi Volume(%)


92






MPa.




yaitu 0,895 MPa.

93

4.3. Pengujian Impak

4.3.1. Data Hasil Pengujian Impak Rata-rata Pada Alkali 2 Jam

Tabel 4.25. Hasil Data Pengujian Impak Alkali 2 Jam

Spesimen Kekuatan Impak Rata-

Rata Energi yang terserap Rata-rata

20 % T1 0,433 2,522

30 % T1 0,467 3,761

40 % T1 0,700 7,016

50 % T1 0,733 7,289

20 % T2 0,867 9,254

30 % T2 0,767 12,047

40 % T2 0,600 9,716

50 % T2 0,967 18,619

20 % T3 1,067 17,757

30 % T3 1,133 21,379

40 % T3 1,167 23,307

50 % T3 1,067 23,421

20 % T4 1,433 29,375

30 % T4 1,133 28,023

40 % T4 1,267 32,180

50 % T4 1,500 35,908

20 % T5 1,667 47,014

30 % T5 1,633 45,242

40 % T5 1,733 48,920

50 % T5 1,700 48,555

94

Gambar 4.29. Grafik hubungan Harga Impak rata-rata dengan


Gambar 4.30. Grafik Hubungan Energi Serap Impak Rata-rata

dengan Fraksi Volume Terhadap Tebal Komposit.

0,733

0,9671,067

1,5

1,7

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

0% 10% 20% 30% 40% 50% 60%

Har

ga im

pak

rat

a-r

ata

(J/m

m2 )

Fraksi volume(%)

Tebal 1mm Tebal 2mm Tebal 3mm Tebal 4mm tebal 5mm

7,289

18,61923,421

35,908

48,555

0

10

20

30

40

50

60

0% 10% 20% 30% 40% 50% 60%

Ene

rgi t

ers

era

p im

pak

rat

a-r

ata

(J/m

m2 )

Fraksi volume(%)


95

4.3.1.1 Pembahasan Pengujian Impak Dengan Alkali 2 Jam

Dari hasil pengujian Impak didapatkan harga yang paling

optimal pada Vf 40% dengan tebal 5mm yaitu sebesar 1,733 J/mm2


20% pada tebal 1mm yang mempunyai harga Impak rata- rata

0,433 J/mm². Hal ini dipengaruhi oleh luasan daerah Impak semakin

luas daerah Impak semakin kecil pula harga Impak komposit

tersebut.

Dan energi terserap Impak yang paling tinggi pada Vf 40%

dengan tebal 5mm yaitu sebesar 48,920 J/mm2 sedangkan yang

terendah adalah komposit serat rami dengan Vf 20% pada tebal

1mm yang mempunyai harga Impak rata- rata 2,522 J/mm².

96





20 % T1 0,500 3,188

30 % T1 0,533 4,343

40 % T1 0,700 7,428

50 % T1 0,767 7,578

20 % T2 0,833 8,869

30 % T2 0,800 12,586

40 % T2 0,700 11,254

50 % T2 1,000 19,304

20 % T3 1,133 18,873

30 % T3 1,233 23,236

40 % T3 1,067 21,357

50 % T3 1,433 31,457

20 % T4 1,467 30,026

30 % T4 1,233 30,384

40 % T4 1,533 38,947

50 % T4 1,567 37,683

20 % T5 1,467 41,267

30 % T5 1,633 45,155

40 % T5 1,767 49,961

50 % T5 1,767 50,555

97

Gambar 4.31. Grafik hubungan Harga Impak rata-rata dengan fraksi


Gambar 4.32. Grafik Hubungan Energi Serap Impak Rata-rata dengan

Fraksi Volume Terhadap Tebal Komposit.

0,767

1

1,4331,567

1,767

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

0% 10% 20% 30% 40% 50% 60%

Har

ga im

pak

rat

a-r

ata

(J/m

m2 )

Fraksi volume(%)


7,578

19,304

31,457

37,683

50,555

0

10

20

30

40

50

60

0% 10% 20% 30% 40% 50% 60%

Ene

rgi t

ers

era

p im

pak

rat

a-r

ata

(J/m

m2 )

Fraksi volume(%)


98



optimal pada Vf 40% dan Vf 50% dengan tebal 5mm yaitu sebesar

1,767 J/mm2 sedangkan yang terendah adalah komposit serat rami

dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak rata-

rata 0,500 J/mm².





99





20 % T1 0,533 3,206

30 % T1 0,500 3,998

40 % T1 0,600 5,669

50 % T1 0,700 6,962

20 % T2 0,900 9,562

30 % T2 0,733 11,541

40 % T2 0,800 12,506

50 % T2 1,133 15,720

20 % T3 1,000 16,701

30 % T3 1,267 23,711

40 % T3 1,267 25,206

50 % T3 1,333 29,245

20 % T4 1,233 25,240

30 % T4 1,267 31,399

40 % T4 1,533 38,979

50 % T4 1,733 41,514

20 % T5 1,567 44,231

30 % T5 1,667 46,135

40 % T5 1,700 48,132

50 % T5 1,833 52,704

100




Fraksi Volume Terhadap Tebal Komposit.

0,7

1,133

1,333

1,7331,833

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

0% 10% 20% 30% 40% 50% 60%

Har

ga im

pak

rat

a-r

ata

(J/m

m2)

Fraksi volume(%)


6,962

15,72

29,245

41,514

52,704

0

10

20

30

40

50

60

0% 10% 20% 30% 40% 50% 60%

Ene

rgi t

ers

era

p im

pak

rat

a-r

ata

(J/m

m2 )

Fraksi volume(%)


101





30% pada tebal 1mm yang mempunyai harga Impak rata- rata

0,500 J/mm².





102





20 % T1 0,533 3,273

30 % T1 0,533 4,409

40 % T1 0,667 6,045

50 % T1 0,800 7,949

20 % T2 0,833 8,904

30 % T2 0,967 15,213

40 % T2 0,767 11,922

50 % T2 0,933 12,997

20 % T3 1,133 18,873

30 % T3 1,167 21,833

40 % T3 1,233 24,468

50 % T3 1,367 29,980

20 % T4 1,133 23,191

30 % T4 1,433 35,444

40 % T4 1,433 36,438

50 % T4 1,700 40,737

20 % T5 1,633 46,026

30 % T5 1,600 44,432

40 % T5 1,667 46,971

50 % T5 1,733 47,617

103




Fraksi Volume Terhadap Tebal Komposit

0,80,933

1,367

1,71,733

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

0% 10% 20% 30% 40% 50% 60%

Har

ga im

pak

rat

a-r

ata

(J/m

m2 )

Fraksi volume(%)


7,94912,997

29,98

40,737

47,617

05

101520253035404550

0% 10% 20% 30% 40% 50% 60%

Ene

rgi t

ers

era

p im

pak

rat

a-r

ata

(J/m

m2 )

Fraksi volume(%)


104





20%, 30% pada tebal 1mm yang mempunyai harga Impak rata- rata

0,533 J/mm².




1mm yang mempunyai harga Impak rata- rata 3,273 J/mm².Hal ini

dipengaruhi oleh fraksi volume dan ketebalan spesimen,semakin

tebal dan meningkatnya fraksi volume maka harga energi serapnya

meningkat.

105

4.4. Pengamatan Stuktur Makro

Pengamatan struktur makro dilakukan pada bentuk patahan

benda uji. Berikut ini adalah data gambar-gambar foto patahan makro,

seperti ditunjukkan pada gambar:

Vf 40% 3mm 2 jam Vf 40% 2mm 4 jam


Gambar 4.37.Contoh Patahan Spesimen pada Uji Bending dengan

perbedaan waktu alkali.

Vf 40% 5mm 2 jam

Broken fiber

Kegagalan

akibat patah

getas

Serat rami

Matrik

Serat rami

Matrik

Patahan akibat gaya

tekan

an

Patahan akibat gaya tekan

Patahan akibat gaya tarik

1mm

Patahan akibat gaya

tarik

1mm 1mm

1mm 1mm

1mm

106

Vf 40% 5mm 4 jam

Vf 50% 5mm 6 jam

Vf 50% 5mm 8 jam

Gambar 4.38.Contoh Patahan spesimen pada Uji Impak dengan


Broken fiber

Kegagalan

akibat patah

getas

Serat rami

Matrik

1mm

1mm

1mm

107



Gambar 4.39.Contoh Patahan spesimen pada Uji Tarik dengan


4.4.1. Pembahasan Foto Patahan

Dari hasi foto patahan dapat dilihat bahwa jenis patahan

yang terjadi adalah patahan jenis broken fiber. Patahan broken

fiber yaitu patahan pada spesimen dimana serat mengalami patah

Broken fiber

Serat rami

Matrik

Kegagalan

akibat patah

getas

Broken fiber

1mm

1mm 1mm

1mm

108

atau rusak dan membentuk seperti serabut. Hal ini disebabkan

oleh distribusi matrik dengan serat kurang merata dan adanya void

di sekitar serat.

Pada bentuk patahan dapat disimpulkan bahwa jenis

patahan yang terjadi adalah patah getas. Arah dari perambatan

retak adalah tegak lurus dengan arah tegangan tarik yang bekerja

dan menghasilkan permukaan yang relatif rata.

109

BAB V

KESIMPULAN DAN SARAN

5.1. KESIMPULAN

Dari hasil penelitian dan analisa pengujian serta pembahasan data

yang diperoleh, dapat disimpulkan:

1 Kekuatan bending rata-rata komposit serat (fibrous composite)

serat rami acak dengan perlakuan alkali 2 jam,4 jam,6 jam dan 8

jam yang optimal yaitu :

Pada alkali 2 jam tebal 3mm Vf 40% sebesar 143,9594 MPa.




Dari data-data yang telah diperoleh menunjukkan harga

kekuatan bending yang paling optimal yaitu pada alkali 2 jam

tebal spesimen 3mm Vf 40% yaitu sebesar 143,9594 MPa.

2 Untuk harga tarik rata-rata komposit serat (fibrous composite)







109

110

Dari data-data yang telah diperoleh harga tarik yang

paling optimal komposit serat rami acak yaitu pada alkali 2 jam

tebal 5mm Vf 50% sebesar 12,644 MPa.

3 Kekuatan impak rata-rata komposit serat (fibrous composite)



Pada alkali 2 jam tebal 5mm Vf 40% sebesar 1,733 J/mm2




Dari data-data yang telah diperoleh menunjukkan harga

kekuatan impak yang paling optimal yaitu pada alkali 6 jam tebal

spesimen 5mm Vf 50% yaitu sebesar 1,833 J/mm2

4 Pengamatan Foto Makro

Dari hasi foto patahan dapat dilihat bahwa jenis patahan

yang terjadi adalah patahan jenis broken fiber. Patahan broken

fiber yaitu patahan pada spesimen dimana serat mengalami

patah atau rusak dan membentuk seperti serabut.

Pada bentuk patahan dapat disimpulkan bahwa jenis

patahan yang terjadi adalah patah getas. Arah dari perambatan

retak adalah tegak lurus dengan arah tegangan tarik yang

bekerja dan menghasilkan permukaan yang relatif rata.

111

5.2. SARAN

Dari hasil proses percetakan ada beberapa hal yang perlu

diperhatikan, diantaranya:

1 Pada proses pembuatan serat acak hendaknya serat disusun

merata agar memudahkan pencetakan,dan menghasilkan

cetakan komposit yang tebalnya sama dalam satu bidang.

2 Meminimalkan keberadaan rongga udara (void) pada komposit

yang akan dibuat sehingga akan menaikkan kekuatan komposit

dengan menggunakan alat tekan yang lebih baik.

3 Dalam melakukan pembuatan benda uji hendaknya memakai

alat pengaman, karena bahan benda uji merupakan bahan

kimia.

4 Pada proses penuangan matrik kedalam serat harus merata

dan cepat agar serat benar-benar terbungkus oleh matrik,

sehingga dapat meminimalkan terjadinya void.

5 Dalam melakukan pengujian hendaknya dilakukan sendiri agar

kita mengetahui proses pengujian tersebut.

DAFTAR PUSTAKA

ASTM. D 790 – 02 Standard test methods for flexural properties of unreinforced and reinforced plastics and electrical insulating material. Philadelphia, PA : American Society for Testing and Materials.

ASTM. D 570 – 98 Standard test method for water absorption of plastics.

Philadelphia, PA : American Society for Testing and Materials. ASTM. D 256 – 00 Standard test methods for determining the izod

pendulum impact resistance of plastics. ASTM. D 638-02 Standart test method for tensile properties of plastics.

Philadelphia, PA : American Society for Testing and Materials. Callister, W. D., 2007, Material Science and Enginering, An Introduction

7ed, Department of Metallurgical Enginering The University of Utah, John Willey and Sons, Inc.

Diharjo, K., dan Triyono, T., 2003, Buku Pegangan Kuliah Material Teknik,

Universitas Sebelas Maret, Surakarta. Fajar, S.N., 2008, Optimasi Kekuatan Bending Dan Impact Komposit

Berpenguat Serat Ramie Bermatrik Polyester Bqtn 157 Terhadap Fraksi Volume Dan Tebal Skin

Gibson, 1994.Principle Of Composite Material Mechanics. New York : Mc

Graw Hill,Inc. Nurkholis., 2008, Analisis Sifat Tarik dan Impak Komposit Serat Rami

Dengan Perlakuan Alkali Dalam Waktu 2, 4, 6, dan 8 jam, Fraksi Volume Serat 10% Dengan Matrik Poliester BQTN 157.

Harper, A. C., 1996, Handbook of Plastics, Elastomers and Composites,

Mc Graw Hill Componies, Inc. Jones, M. R., 1975, Mechanics of Composite Material, Mc Graww Hill

Kogakusha, Ltd. Junaedi, 2008, Penelitian Kekuatan Tarik dan Impak Komposit

Serat Rami Dengan Variasi Panjang Serat 25mm, 50mm, dan 100mm, Dengan Fraksi Volume Serat 10% Dengan Matrik Poliester BQTN 157.

Lukkassen, Dag dan Annette Meidell. 13 Oktober 2003. Advanced Materials and Structures and their Fabrication Processes, edisi III. HiN: NarvikUniversity College.

Mueler, Dieter H. October 2003. New Discovery in the Properties of

Composites Reinforced with Natural Fibers. JOURNAL OF INDUSTRIAL TEXTILES, Vol. 33, No. 2. Sage Publications.

Nanang, 2006, Penelitian Kekuatan Bending Dan Impak Komposit Serat

Kenaf Tanpa Perlakuan Alkali Dengan Fraksi Volume Serat 10%, 15% dan 20% Dengan Matrik Poliester.

Saprudin, 2004, Penelitian Kekuatan Bending dan Impak Komposit Serat

Kenaf Tanpa Perlakuan Alkali Dengan Fraksi Volume Serat 30% dan 40%.

Surdia, 1992, Pengetahuan Bahan Teknik, FT, Pradnaya Paramita,

Jakarta. Van Vlack, 2005, Ilmu dan Teknologi Bahan, Erlangga Jakarta.

http://www.kemahasiswaan.its.ac.id.pdf : 15 Januari 2008 http://www.iptek.net.id/ind/?mnu=8&ch=jsti&id=115 : 20 Agustus 2008 http://www.gatra.com/2006-01-01/versi_cetak.php?id=91072 : 20 Agustus 2008

http://www.iptek.net.id/ind/?mnu=8&ch=jsti&id=115

http://www.gatra.com/2006-01-01/versi_cetak.php?id=91072

Designation: D 638 – 02 An American National Standard

Standard Test Method forTensile Properties of Plastics 1

This standard is issued under the fixed designation D 638; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the Department of Defense.

1. Scope *

1.1 This test method covers the determination of the tensileproperties of unreinforced and reinforced plastics in the formof standard dumbbell-shaped test specimens when tested underdefined conditions of pretreatment, temperature, humidity, andtesting machine speed.

1.2 This test method can be used for testing materials of anythickness up to 14 mm (0.55 in.). However, for testingspecimens in the form of thin sheeting, including film less than1.0 mm (0.04 in.) in thickness, Test Methods D 882 is thepreferred test method. Materials with a thickness greater than14 mm (0.55 in.) must be reduced by machining.

1.3 This test method includes the option of determiningPoisson’s ratio at room temperature.

NOTE 1—This test method and ISO 527-1 are technically equivalent.NOTE 2—This test method is not intended to cover precise physical

procedures. It is recognized that the constant rate of crosshead movementtype of test leaves much to be desired from a theoretical standpoint, thatwide differences may exist between rate of crosshead movement and rateof strain between gage marks on the specimen, and that the testing speedsspecified disguise important effects characteristic of materials in theplastic state. Further, it is realized that variations in the thicknesses of testspecimens, which are permitted by these procedures, produce variations inthe surface-volume ratios of such specimens, and that these variations mayinfluence the test results. Hence, where directly comparable results aredesired, all samples should be of equal thickness. Special additional testsshould be used where more precise physical data are needed.

NOTE 3—This test method may be used for testing phenolic moldedresin or laminated materials. However, where these materials are used aselectrical insulation, such materials should be tested in accordance withTest Methods D 229 and Test Method D 651.

NOTE 4—For tensile properties of resin-matrix composites reinforcedwith oriented continuous or discontinuous high modulus >20-GPa(>3.03 106-psi) fibers, tests shall be made in accordance with TestMethod D 3039/D 3039M.

1.4 Test data obtained by this test method are relevant andappropriate for use in engineering design.

1.5 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.

1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.

2. Referenced Documents

2.1 ASTM Standards:D 229 Test Methods for Rigid Sheet and Plate Materials

Used for Electrical Insulation2

D 412 Test Methods for Vulcanized Rubber and Thermo-plastic Elastomers—Tension3

D 618 Practice for Conditioning Plastics for Testing4

D 651 Test Method for Tensile Strength of Molded Electri-cal Insulating Materials5

D 882 Test Methods for Tensile Properties of Thin PlasticSheeting4

D 883 Terminology Relating to Plastics4

D 1822 Test Method for Tensile-Impact Energy to BreakPlastics and Electrical Insulating Materials4

D 3039/D 3039M Test Method for Tensile Properties ofPolymer Matrix Composite Materials6

D 4000 Classification System for Specifying Plastic Mate-rials7

D 4066 Classification System for Nylon Injection and Ex-trusion Materials7

D 5947 Test Methods for Physical Dimensions of SolidPlastic Specimens8

E 4 Practices for Force Verification of Testing Machines9

E 83 Practice for Verification and Classification of Exten-someter9

E 132 Test Method for Poisson’s Ratio at Room Tempera-ture9

E 691 Practice for Conducting an Interlaboratory Study to

1 This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.

Current edition approved April 10, 2002. Published June 2002. Originallypublished as D 638 – 41 T. Last previous edition D 638 – 01.

2 Annual Book of ASTM Standards, Vol 10.01.3 Annual Book of ASTM Standards, Vol 09.01.4 Annual Book of ASTM Standards, Vol 08.01.5 Discontinued; see1994 Annual Book of ASTM Standards, Vol 10.01.6 Annual Book of ASTM Standards, Vol 15.03.7 Annual Book of ASTM Standards, Vol 08.02.8 Annual Book of ASTM Standards, Vol 08.03.9 Annual Book of ASTM Standards, Vol 03.01.

1

*A Summary of Changes section appears at the end of this standard.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

Determine the Precision of a Test Method10

2.2 ISO Standard:ISO 527-1 Determination of Tensile Properties11

3. Terminology

3.1 Definitions—Definitions of terms applying to this testmethod appear in Terminology D 883 and Annex A2.

4. Significance and Use

4.1 This test method is designed to produce tensile propertydata for the control and specification of plastic materials. Thesedata are also useful for qualitative characterization and forresearch and development. For many materials, there may be aspecification that requires the use of this test method, but withsome procedural modifications that take precedence whenadhering to the specification. Therefore, it is advisable to referto that material specification before using this test method.Table 1 in Classification D 4000 lists the ASTM materialsstandards that currently exist.

4.2 Tensile properties may vary with specimen preparationand with speed and environment of testing. Consequently,where precise comparative results are desired, these factorsmust be carefully controlled.

4.2.1 It is realized that a material cannot be tested withoutalso testing the method of preparation of that material. Hence,when comparative tests of materials per se are desired, thegreatest care must be exercised to ensure that all samples areprepared in exactly the same way, unless the test is to includethe effects of sample preparation. Similarly, for referee pur-poses or comparisons within any given series of specimens,care must be taken to secure the maximum degree of unifor-mity in details of preparation, treatment, and handling.

4.3 Tensile properties may provide useful data for plasticsengineering design purposes. However, because of the highdegree of sensitivity exhibited by many plastics to rate ofstraining and environmental conditions, data obtained by thistest method cannot be considered valid for applications involv-ing load-time scales or environments widely different fromthose of this test method. In cases of such dissimilarity, noreliable estimation of the limit of usefulness can be made formost plastics. This sensitivity to rate of straining and environ-ment necessitates testing over a broad load-time scale (includ-ing impact and creep) and range of environmental conditions iftensile properties are to suffice for engineering design pur-poses.

NOTE 5—Since the existence of a true elastic limit in plastics (as inmany other organic materials and in many metals) is debatable, thepropriety of applying the term “elastic modulus” in its quoted, generallyaccepted definition to describe the “stiffness” or “rigidity” of a plastic hasbeen seriously questioned. The exact stress-strain characteristics of plasticmaterials are highly dependent on such factors as rate of application ofstress, temperature, previous history of specimen, etc. However, stress-strain curves for plastics, determined as described in this test method,almost always show a linear region at low stresses, and a straight linedrawn tangent to this portion of the curve permits calculation of an elastic

modulus of the usually defined type. Such a constant is useful if itsarbitrary nature and dependence on time, temperature, and similar factorsare realized.

4.4 Poisson’s Ratio—When uniaxial tensile force is appliedto a solid, the solid stretches in the direction of the appliedforce (axially), but it also contracts in both dimensions lateralto the applied force. If the solid is homogeneous and isotropic,and the material remains elastic under the action of the appliedforce, the lateral strain bears a constant relationship to the axialstrain. This constant, called Poisson’s ratio, is defined as thenegative ratio of the transverse (negative) to axial strain underuniaxial stress.

4.4.1 Poisson’s ratio is used for the design of structures inwhich all dimensional changes resulting from the applicationof force need to be taken into account and in the application ofthe generalized theory of elasticity to structural analysis.

NOTE 6—The accuracy of the determination of Poisson’s ratio isusually limited by the accuracy of the transverse strain measurementsbecause the percentage errors in these measurements are usually greaterthan in the axial strain measurements. Since a ratio rather than an absolutequantity is measured, it is only necessary to know accurately the relativevalue of the calibration factors of the extensometers. Also, in general, thevalue of the applied loads need not be known accurately.

5. Apparatus

5.1 Testing Machine—A testing machine of the constant-rate-of-crosshead-movement type and comprising essentiallythe following:

5.1.1 Fixed Member—A fixed or essentially stationarymember carrying one grip.

5.1.2 Movable Member—A movable member carrying asecond grip.

5.1.3 Grips—Grips for holding the test specimen betweenthe fixed member and the movable member of the testingmachine can be either the fixed or self-aligning type.

5.1.3.1 Fixed grips are rigidly attached to the fixed andmovable members of the testing machine. When this type ofgrip is used extreme care should be taken to ensure that the testspecimen is inserted and clamped so that the long axis of thetest specimen coincides with the direction of pull through thecenter line of the grip assembly.

5.1.3.2 Self-aligning grips are attached to the fixed andmovable members of the testing machine in such a manner thatthey will move freely into alignment as soon as any load isapplied so that the long axis of the test specimen will coincidewith the direction of the applied pull through the center line ofthe grip assembly. The specimens should be aligned as per-fectly as possible with the direction of pull so that no rotarymotion that may induce slippage will occur in the grips; thereis a limit to the amount of misalignment self-aligning grips willaccommodate.

5.1.3.3 The test specimen shall be held in such a way thatslippage relative to the grips is prevented insofar as possible.Grip surfaces that are deeply scored or serrated with a patternsimilar to those of a coarse single-cut file, serrations about 2.4mm (0.09 in.) apart and about 1.6 mm (0.06 in.) deep, havebeen found satisfactory for most thermoplastics. Finer serra-tions have been found to be more satisfactory for harderplastics, such as the thermosetting materials. The serrations

10 Annual Book of ASTM Standards, Vol 14.02.11 Available from American National Standards Institute, 25 W. 43rd St., 4th

Floor, New York, NY 10036.

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should be kept clean and sharp. Breaking in the grips mayoccur at times, even when deep serrations or abraded specimensurfaces are used; other techniques must be used in these cases.Other techniques that have been found useful, particularly withsmooth-faced grips, are abrading that portion of the surface ofthe specimen that will be in the grips, and interposing thinpieces of abrasive cloth, abrasive paper, or plastic, or rubber-coated fabric, commonly called hospital sheeting, between thespecimen and the grip surface. No. 80 double-sided abrasivepaper has been found effective in many cases. An open-meshfabric, in which the threads are coated with abrasive, has alsobeen effective. Reducing the cross-sectional area of the speci-men may also be effective. The use of special types of grips issometimes necessary to eliminate slippage and breakage in thegrips.

5.1.4 Drive Mechanism—A drive mechanism for impartingto the movable member a uniform, controlled velocity withrespect to the stationary member, with this velocity to beregulated as specified in Section 8.

5.1.5 Load Indicator—A suitable load-indicating mecha-nism capable of showing the total tensile load carried by thetest specimen when held by the grips. This mechanism shall beessentially free of inertia lag at the specified rate of testing andshall indicate the load with an accuracy of61 % of theindicated value, or better. The accuracy of the testing machineshall be verified in accordance with Practices E 4.

NOTE 7—Experience has shown that many testing machines now in useare incapable of maintaining accuracy for as long as the periods betweeninspection recommended in Practices E 4. Hence, it is recommended thateach machine be studied individually and verified as often as may befound necessary. It frequently will be necessary to perform this functiondaily.

5.1.6 The fixed member, movable member, drive mecha-nism, and grips shall be constructed of such materials and insuch proportions that the total elastic longitudinal strain of thesystem constituted by these parts does not exceed 1 % of thetotal longitudinal strain between the two gage marks on the testspecimen at any time during the test and at any load up to therated capacity of the machine.

5.2 Extension Indicator(extensometer)—A suitable instru-ment shall be used for determining the distance between twodesignated points within the gage length of the test specimen asthe specimen is stretched. For referee purposes, the extensom-eter must be set at the full gage length of the specimen, asshown in Fig. 1. It is desirable, but not essential, that thisinstrument automatically record this distance, or any change init, as a function of the load on the test specimen or of theelapsed time from the start of the test, or both. If only the latteris obtained, load-time data must also be taken. This instrumentshall be essentially free of inertia at the specified speed oftesting. Extensometers shall be classified and their calibrationperiodically verified in accordance with Practice E 83.

5.2.1 Modulus-of-Elasticity Measurements—For modulus-of-elasticity measurements, an extensometer with a maximumstrain error of 0.0002 mm/mm (in./in.) that automatically andcontinuously records shall be used. An extensometer classifiedby Practice E 83 as fulfilling the requirements of a B-2classification within the range of use for modulus measure-

ments meets this requirement.5.2.2 Low-Extension Measurements—For elongation-at-

yield and low-extension measurements (nominally 20 % orless), the same above extensometer, attenuated to 20 % exten-sion, may be used. In any case, the extensometer system mustmeet at least Class C (Practice E 83) requirements, whichinclude a fixed strain error of 0.001 strain or61.0 % of theindicated strain, whichever is greater.

5.2.3 High-Extension Measurements—For making mea-surements at elongations greater than 20 %, measuring tech-niques with error no greater than610 % of the measured valueare acceptable.

5.2.4 Poisson’s Ratio—Bi-axial extensometer or axial andtransverse extensometers capable of recording axial strain andtransverse strain simultaneously. The extensometers shall becapable of measuring the change in strains with an accuracy of1 % of the relevant value or better.

NOTE 8—Strain gages can be used as an alternative method to measureaxial and transverse strain; however, proper techniques for mountingstrain gages are crucial to obtaining accurate data. Consult strain gagesuppliers for instruction and training in these special techniques.

5.3 Micrometers—Suitable micrometers for measuring thewidth and thickness of the test specimen to an incrementaldiscrimination of at least 0.025 mm (0.001 in.) should be used.All width and thickness measurements of rigid and semirigidplastics may be measured with a hand micrometer with ratchet.A suitable instrument for measuring the thickness of nonrigidtest specimens shall have:(1) a contact measuring pressure of25 6 2.5 kPa (3.66 0.36 psi),(2) a movable circular contactfoot 6.356 0.025 mm (0.2506 0.001 in.) in diameter, and(3)a lower fixed anvil large enough to extend beyond the contactfoot in all directions and being parallel to the contact footwithin 0.005 mm (0.0002 in.) over the entire foot area. Flatnessof the foot and anvil shall conform to Test Method D 5947.

5.3.1 An optional instrument equipped with a circular con-tact foot 15.886 0.08 mm (0.6256 0.003 in.) in diameter isrecommended for thickness measuring of process samples orlarger specimens at least 15.88 mm in minimum width.

6. Test Specimens

6.1 Sheet, Plate, and Molded Plastics:6.1.1 Rigid and Semirigid Plastics—The test specimen shall

conform to the dimensions shown in Fig. 1. The Type Ispecimen is the preferred specimen and shall be used wheresufficient material having a thickness of 7 mm (0.28 in.) or lessis available. The Type II specimen may be used when amaterial does not break in the narrow section with the preferredType I specimen. The Type V specimen shall be used whereonly limited material having a thickness of 4 mm (0.16 in.) orless is available for evaluation, or where a large number ofspecimens are to be exposed in a limited space (thermal andenvironmental stability tests, etc.). The Type IV specimenshould be used when direct comparisons are required betweenmaterials in different rigidity cases (that is, nonrigid andsemirigid). The Type III specimen must be used for allmaterials with a thickness of greater than 7 mm (0.28 in.) butnot more than 14 mm (0.55 in.).

6.1.2 Nonrigid Plastics—The test specimen shall conformto the dimensions shown in Fig. 1. The Type IV specimen shall

D 638

3

be used for testing nonrigid plastics with a thickness of 4 mm(0.16 in.) or less. The Type III specimen must be used for allmaterials with a thickness greater than 7 mm (0.28 in.) but notmore than 14 mm (0.55 in.).

6.1.3 Reinforced Composites—The test specimen for rein-forced composites, including highly orthotropic laminates,shall conform to the dimensions of the Type I specimen shownin Fig. 1.

Specimen Dimensions for Thickness, T, mm (in.)A

Dimensions (see drawings)7 (0.28) or under Over 7 to 14 (0.28 to 0.55), incl 4 (0.16) or under

TolerancesType I Type II Type III Type IVB Type VC,D

W—Width of narrow sectionE,F 13 (0.50) 6 (0.25) 19 (0.75) 6 (0.25) 3.18 (0.125) 60.5 (60.02)B,C

L—Length of narrow section 57 (2.25) 57 (2.25) 57 (2.25) 33 (1.30) 9.53 (0.375) 60.5 (60.02)C

WO—Width overall, minG 19 (0.75) 19 (0.75) 29 (1.13) 19 (0.75) ... + 6.4 ( + 0.25)WO—Width overall, minG ... ... ... ... 9.53 (0.375) + 3.18 ( + 0.125)LO—Length overall, minH 165 (6.5) 183 (7.2) 246 (9.7) 115 (4.5) 63.5 (2.5) no max (no max)G—Gage lengthI 50 (2.00) 50 (2.00) 50 (2.00) ... 7.62 (0.300) 60.25 (60.010)C

G—Gage lengthI ... ... ... 25 (1.00) ... 60.13 (60.005)D—Distance between grips 115 (4.5) 135 (5.3) 115 (4.5) 65 (2.5)J 25.4 (1.0) 65 (60.2)R—Radius of fillet 76 (3.00) 76 (3.00) 76 (3.00) 14 (0.56) 12.7 (0.5) 61 (60.04)C

RO—Outer radius (Type IV) ... ... ... 25 (1.00) ... 61 (60.04)

A Thickness, T, shall be 3.26 0.4 mm (0.13 6 0.02 in.) for all types of molded specimens, and for other Types I and II specimens where possible. If specimens aremachined from sheets or plates, thickness, T, may be the thickness of the sheet or plate provided this does not exceed the range stated for the intended specimen type.For sheets of nominal thickness greater than 14 mm (0.55 in.) the specimens shall be machined to 14 6 0.4 mm (0.55 6 0.02 in.) in thickness, for use with the Type IIIspecimen. For sheets of nominal thickness between 14 and 51 mm (0.55 and 2 in.) approximately equal amounts shall be machined from each surface. For thicker sheetsboth surfaces of the specimen shall be machined, and the location of the specimen with reference to the original thickness of the sheet shall be noted. Tolerances onthickness less than 14 mm (0.55 in.) shall be those standard for the grade of material tested.

B For the Type IV specimen, the internal width of the narrow section of the die shall be 6.00 6 0.05 mm (0.2506 0.002 in.). The dimensions are essentially those of DieC in Test Methods D 412.

C The Type V specimen shall be machined or die cut to the dimensions shown, or molded in a mold whose cavity has these dimensions. The dimensions shall be:W = 3.18 6 0.03 mm (0.125 6 0.001 in.),L = 9.53 6 0.08 mm (0.375 6 0.003 in.),G = 7.62 6 0.02 mm (0.300 6 0.001 in.), andR = 12.7 6 0.08 mm (0.500 6 0.003 in.).

The other tolerances are those in the table.D Supporting data on the introduction of the L specimen of Test Method D 1822 as the Type V specimen are available from ASTM Headquarters. Request RR:D20-1038.E The width at the center Wc shall be +0.00 mm, −0.10 mm ( +0.000 in., −0.004 in.) compared with width W at other parts of the reduced section. Any reduction in W

at the center shall be gradual, equally on each side so that no abrupt changes in dimension result.F For molded specimens, a draft of not over 0.13 mm (0.005 in.) may be allowed for either Type I or II specimens 3.2 mm (0.13 in.) in thickness, and this should be taken

into account when calculating width of the specimen. Thus a typical section of a molded Type I specimen, having the maximum allowable draft, could be as follows:G Overall widths greater than the minimum indicated may be desirable for some materials in order to avoid breaking in the grips.H Overall lengths greater than the minimum indicated may be desirable either to avoid breaking in the grips or to satisfy special test requirements.I Test marks or initial extensometer span.J When self-tightening grips are used, for highly extensible polymers, the distance between grips will depend upon the types of grips used and may not be critical if

maintained uniform once chosen.

FIG. 1 Tension Test Specimens for Sheet, Plate, and Molded Plastics

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6.1.4 Preparation—Test specimens shall be prepared bymachining operations, or die cutting, from materials in sheet,plate, slab, or similar form. Materials thicker than 14 mm (0.55in.) must be machined to 14 mm (0.55 in.) for use as Type IIIspecimens. Specimens can also be prepared by molding thematerial to be tested.

NOTE 9—Test results have shown that for some materials such as glasscloth, SMC, and BMC laminates, other specimen types should beconsidered to ensure breakage within the gage length of the specimen, asmandated by 7.3.

NOTE 10—When preparing specimens from certain composite lami-nates such as woven roving, or glass cloth, care must be exercised incutting the specimens parallel to the reinforcement. The reinforcementwill be significantly weakened by cutting on a bias, resulting in lowerlaminate properties, unless testing of specimens in a direction other thanparallel with the reinforcement constitutes a variable being studied.

NOTE 11—Specimens prepared by injection molding may have differenttensile properties than specimens prepared by machining or die-cuttingbecause of the orientation induced. This effect may be more pronouncedin specimens with narrow sections.

6.2 Rigid Tubes—The test specimen for rigid tubes shall beas shown in Fig. 2. The length,L, shall be as shown in the tablein Fig. 2. A groove shall be machined around the outside of thespecimen at the center of its length so that the wall section aftermachining shall be 60 % of the original nominal wall thick-ness. This groove shall consist of a straight section 57.2 mm(2.25 in.) in length with a radius of 76 mm (3 in.) at each endjoining it to the outside diameter. Steel or brass plugs havingdiameters such that they will fit snugly inside the tube andhaving a length equal to the full jaw length plus 25 mm (1 in.)shall be placed in the ends of the specimens to preventcrushing. They can be located conveniently in the tube byseparating and supporting them on a threaded metal rod.Details of plugs and test assembly are shown in Fig. 2.

6.3 Rigid Rods—The test specimen for rigid rods shall be asshown in Fig. 3. The length,L, shall be as shown in the tablein Fig. 3. A groove shall be machined around the specimen atthe center of its length so that the diameter of the machinedportion shall be 60 % of the original nominal diameter. Thisgroove shall consist of a straight section 57.2 mm (2.25 in.) inlength with a radius of 76 mm (3 in.) at each end joining it tothe outside diameter.

6.4 All surfaces of the specimen shall be free of visibleflaws, scratches, or imperfections. Marks left by coarse ma-chining operations shall be carefully removed with a fine file orabrasive, and the filed surfaces shall then be smoothed withabrasive paper (No. 00 or finer). The finishing sanding strokesshall be made in a direction parallel to the long axis of the testspecimen. All flash shall be removed from a molded specimen,taking great care not to disturb the molded surfaces. Inmachining a specimen, undercuts that would exceed thedimensional tolerances shown in Fig. 1 shall be scrupulouslyavoided. Care shall also be taken to avoid other commonmachining errors.

6.5 If it is necessary to place gage marks on the specimen,this shall be done with a wax crayon or India ink that will notaffect the material being tested. Gage marks shall not bescratched, punched, or impressed on the specimen.

6.6 When testing materials that are suspected of anisotropy,

duplicate sets of test specimens shall be prepared, having theirlong axes respectively parallel with, and normal to, thesuspected direction of anisotropy.

7. Number of Test Specimens

7.1 Test at least five specimens for each sample in the caseof isotropic materials.

DIMENSIONS OF ROD SPECIMENS

Nominal Diam-eter

Length of RadialSections, 2R.S.

Total CalculatedMinimum

Length of Specimen

Standard Length, L, ofSpecimen to Be Used

for 89-mm (31⁄2-in.)JawsA

mm (in.)

3.2 (1⁄8) 19.6 (0.773) 356 (14.02) 381 (15)4.7 (1⁄16) 24.0 (0.946) 361 (14.20) 381 (15)6.4 (1⁄4) 27.7 (1.091) 364 (14.34) 381 (15)9.5 (3⁄8) 33.9 (1.333) 370 (14.58) 381 (15)

12.7 (1⁄2) 39.0 (1.536) 376 (14.79) 400 (15.75)15.9 (5⁄8) 43.5 (1.714) 380 (14.96) 400 (15.75)19.0 (3⁄4) 47.6 (1.873) 384 (15.12) 400 (15.75)22.2 (7⁄8) 51.5 (2.019) 388 (15.27) 400 (15.75)25.4 (1) 54.7 (2.154) 391 (15.40) 419 (16.5)

31.8 (11⁄4) 60.9 (2.398) 398 (15.65) 419 (16.5)38.1 (11⁄2) 66.4 (2.615) 403 (15.87) 419 (16.5)42.5 (13⁄4) 71.4 (2.812) 408 (16.06) 419 (16.5)50.8 (2) 76.0 (2.993) 412 (16.24) 432 (17)

A For other jaws greater than 89 mm (3.5 in.), the standard length shall beincreased by twice the length of the jaws minus 178 mm (7 in.). The standardlength permits a slippage of approximately 6.4 to 12.7 mm (0.25 to 0.50 in.) in eachjaw while maintaining the maximum length of the jaw grip.

FIG. 3 Diagram Showing Location of Rod Tension Test Specimenin Testing Machine

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7.2 Test ten specimens, five normal to, and five parallelwith, the principle axis of anisotropy, for each sample in thecase of anisotropic materials.

7.3 Discard specimens that break at some flaw, or that breakoutside of the narrow cross-sectional test section (Fig. 1,dimension “L”), and make retests, unless such flaws constitute

a variable to be studied.

NOTE 12—Before testing, all transparent specimens should be inspectedin a polariscope. Those which show atypical or concentrated strainpatterns should be rejected, unless the effects of these residual strainsconstitute a variable to be studied.

8. Speed of Testing

8.1 Speed of testing shall be the relative rate of motion ofthe grips or test fixtures during the test. The rate of motion ofthe driven grip or fixture when the testing machine is runningidle may be used, if it can be shown that the resulting speed oftesting is within the limits of variation allowed.

8.2 Choose the speed of testing from Table 1. Determinethis chosen speed of testing by the specification for the materialbeing tested, or by agreement between those concerned. Whenthe speed is not specified, use the lowest speed shown in Table1 for the specimen geometry being used, which gives rupturewithin 1⁄2 to 5-min testing time.

8.3 Modulus determinations may be made at the speedselected for the other tensile properties when the recorderresponse and resolution are adequate.

8.4 Poisson’s ratio determinations shall be made at the samespeed selected for modulus determinations.

9. Conditioning

9.1 Conditioning—Condition the test specimens at 2362°C (73.46 3.6°F) and 506 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D 618, unless otherwise specified by contract or therelevant ASTM material specification. Reference pre-test con-ditioning, to settle disagreements, shall apply tolerances of61°C (1.8°F) and62 % relative humidity.

9.2 Test Conditions—Conduct the tests at 236 2°C (73.463.6°F) and 506 5 % relative humidity, unless otherwisespecified by contract or the relevant ASTM material specifica-tion. Reference testing conditions, to settle disagreements,

DIMENSIONS OF TUBE SPECIMENS

Nominal WallThickness

Length of RadialSections,

2R.S.

Total CalculatedMinimum

Length of Specimen

Standard Length, L,of Specimen to BeUsed for 89-mm(3.5-in.) JawsA

mm (in.)

0.79 (1⁄32) 13.9 (0.547) 350 (13.80) 381 (15)1.2 (3⁄64) 17.0 (0.670) 354 (13.92) 381 (15)1.6 (1⁄16) 19.6 (0.773) 356 (14.02) 381 (15)2.4 (3⁄32) 24.0 (0.946) 361 (14.20) 381 (15)3.2 (1⁄8) 27.7 (1.091) 364 (14.34) 381 (15)4.8 (3⁄16) 33.9 (1.333) 370 (14.58) 381 (15)6.4 (1⁄4) 39.0 (1.536) 376 (14.79) 400 (15.75)7.9 (5⁄16) 43.5 (1.714) 380 (14.96) 400 (15.75)9.5 (3⁄8) 47.6 (1.873) 384 (15.12) 400 (15.75)

11.1 (7⁄16) 51.3 (2.019) 388 (15.27) 400 (15.75)12.7 (1⁄2) 54.7 (2.154) 391 (15.40) 419 (16.5)

A For other jaws greater than 89 mm (3.5 in.), the standard length shall beincreased by twice the length of the jaws minus 178 mm (7 in.). The standardlength permits a slippage of approximately 6.4 to 12.7 mm (0.25 to 0.50 in.) in eachjaw while maintaining the maximum length of the jaw grip.

FIG. 2 Diagram Showing Location of Tube Tension TestSpecimens in Testing Machine

TABLE 1 Designations for Speed of Testing A

ClassificationB Specimen TypeSpeed of Testing,mm/min (in./min)

NominalStrainC Rate atStart of Test,mm/mm· min(in./in.·min)

Rigid and Semirigid I, II, III rods andtubes

5 (0.2) 6 25 % 0.1

50 (2) 6 10 % 1500 (20) 6 10 % 10

IV 5 (0.2) 6 25 % 0.1550 (2) 6 10 % 1.5

500 (20) 6 10 % 15V 1 (0.05) 6 25 % 0.1

10 (0.5) 6 25 % 1100 (5)6 25 % 10

Nonrigid III 50 (2) 6 10 % 1500 (20) 6 10 % 10

IV 50 (2) 6 10 % 1.5500 (20) 6 10 % 15

A Select the lowest speed that produces rupture in 1⁄2 to 5 min for the specimengeometry being used (see 8.2).

B See Terminology D 883 for definitions.C The initial rate of straining cannot be calculated exactly for dumbbell-shaped

specimens because of extension, both in the reduced section outside the gagelength and in the fillets. This initial strain rate can be measured from the initial slopeof the tensile strain-versus-time diagram.

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shall apply tolerances of61°C (1.8°F) and62 % relativehumidity.

10. Procedure

10.1 Measure the width and thickness of rigid flat speci-mens (Fig. 1) with a suitable micrometer to the nearest 0.025mm (0.001 in.) at several points along their narrow sections.Measure the thickness of nonrigid specimens (produced by aType IV die) in the same manner with the required dialmicrometer. Take the width of this specimen as the distancebetween the cutting edges of the die in the narrow section.Measure the diameter of rod specimens, and the inside andoutside diameters of tube specimens, to the nearest 0.025 mm(0.001 in.) at a minimum of two points 90° apart; make thesemeasurements along the groove for specimens so constructed.Use plugs in testing tube specimens, as shown in Fig. 2.

10.2 Place the specimen in the grips of the testing machine,taking care to align the long axis of the specimen and the gripswith an imaginary line joining the points of attachment of thegrips to the machine. The distance between the ends of thegripping surfaces, when using flat specimens, shall be asindicated in Fig. 1. On tube and rod specimens, the location forthe grips shall be as shown in Fig. 2 and Fig. 3. Tighten thegrips evenly and firmly to the degree necessary to preventslippage of the specimen during the test, but not to the pointwhere the specimen would be crushed.

10.3 Attach the extension indicator. When modulus is beingdetermined, a Class B-2 or better extensometer is required (see5.2.1).

NOTE 13—Modulus of materials is determined from the slope of thelinear portion of the stress-strain curve. For most plastics, this linearportion is very small, occurs very rapidly, and must be recorded automati-cally. The change in jaw separation is never to be used for calculatingmodulus or elongation.

10.3.1 Poisson’s Ratio Determination:10.3.1.1 When Poisson’s ratio is determined, the speed of

testing and the load range at which it is determined shall be thesame as those used for modulus of elasticity.

10.3.1.2 Attach the transverse strain measuring device. Thetransverse strain measuring device must continuously measurethe strain simultaneously with the axial strain measuringdevice.

10.3.1.3 Make simultaneous measurements of load andstrain and record the data. The precision of the value ofPoisson’s ratio will depend on the number of data points ofaxial and transverse strain taken.

10.4 Set the speed of testing at the proper rate as required inSection 8, and start the machine.

10.5 Record the load-extension curve of the specimen.10.6 Record the load and extension at the yield point (if one

exists) and the load and extension at the moment of rupture.

NOTE 14—If it is desired to measure both modulus and failure proper-ties (yield or break, or both), it may be necessary, in the case of highlyextensible materials, to run two independent tests. The high magnificationextensometer normally used to determine properties up to the yield pointmay not be suitable for tests involving high extensibility. If allowed toremain attached to the specimen, the extensometer could be permanentlydamaged. A broad-range incremental extensometer or hand-rule techniquemay be needed when such materials are taken to rupture.

11. Calculation

11.1 Toe compensation shall be made in accordance withAnnex A1, unless it can be shown that the toe region of thecurve is not due to the take-up of slack, seating of thespecimen, or other artifact, but rather is an authentic materialresponse.

11.2 Tensile Strength—Calculate the tensile strength bydividing the maximum load in newtons (or pounds-force) bythe original minimum cross-sectional area of the specimen insquare metres (or square inches). Express the result in pascals(or pounds-force per square inch) and report it to threesignificant figures as tensile strength at yield or tensile strengthat break, whichever term is applicable. When a nominal yieldor break load less than the maximum is present and applicable,it may be desirable also to calculate, in a similar manner, thecorresponding tensile stress at yield or tensile stress at breakand report it to three significant figures (see Note A2.8).

11.3 Percent Elongation—If the specimen gives a yield loadthat is larger than the load at break, calculate percent elonga-tion at yield. Otherwise, calculate percent elongation at break.Do this by reading the extension (change in gage length) at themoment the applicable load is reached. Divide that extensionby the original gage length and multiply by 100. Report percentelongation at yield or percent elongation at break to twosignificant figures. When a yield or breaking load less than themaximum is present and of interest, it is desirable to calculateand report both percent elongation at yield and percentelongation at break (see Note A2.2).

11.4 Modulus of Elasticity—Calculate the modulus of elas-ticity by extending the initial linear portion of the load-extension curve and dividing the difference in stress corre-sponding to any segment of section on this straight line by thecorresponding difference in strain. All elastic modulus valuesshall be computed using the average initial cross-sectional area

TABLE 2 Modulus, 10 6 psi, for Eight Laboratories, Five Materials

Mean Sr SR Ir IR

Polypropylene 0.210 0.0089 0.071 0.025 0.201Cellulose acetate butyrate 0.246 0.0179 0.035 0.051 0.144Acrylic 0.481 0.0179 0.063 0.051 0.144Glass-reinforced nylon 1.17 0.0537 0.217 0.152 0.614Glass-reinforced polyester 1.39 0.0894 0.266 0.253 0.753

TABLE 3 Tensile Stress at Yield, 10 3 psi, for Eight Laboratories,Three Materials

Mean Sr SR Ir IR

Polypropylene 3.63 0.022 0.161 0.062 0.456Cellulose acetate butyrate 5.01 0.058 0.227 0.164 0.642Acrylic 10.4 0.067 0.317 0.190 0.897

TABLE 4 Elongation at Yield, %, for Eight Laboratories, ThreeMaterials

Mean Sr SR Ir IR

Cellulose acetate butyrate 3.65 0.27 0.62 0.76 1.75Acrylic 4.89 0.21 0.55 0.59 1.56Polypropylene 8.79 0.45 5.86 1.27 16.5

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of the test specimens in the calculations. The result shall beexpressed in pascals (pounds-force per square inch) andreported to three significant figures.

11.5 Secant Modulus—At a designated strain, this shall becalculated by dividing the corresponding stress (nominal) bythe designated strain. Elastic modulus values are preferable andshall be calculated whenever possible. However, for materialswhere no proportionality is evident, the secant value shall becalculated. Draw the tangent as directed in A1.3 and Fig. A1.2,and mark off the designated strain from the yield point wherethe tangent line goes through zero stress. The stress to be usedin the calculation is then determined by dividing the load-extension curve by the original average cross-sectional area ofthe specimen.

11.6 Poisson’s Ratio—The axial strain,ea, indicated by theaxial extensometer, and the transverse strain,e, indicated bythe transverse extensometers, are plotted against the appliedload, P, as shown in Fig. 4. A straight line is drawn througheach set of points, and the slopes,dea / dPanddet / dP, of theselines are determined. Poisson’s ratio, µ, is then calculated asfollows:

µ 5 2~det / dP!/~dea / dP! (1)

where:det = change in transverse strain,dea = change in axial strain, anddP = change in applied load;

or

µ 5 2~det! / ~dea! (2)

11.6.1 The errors that may be introduced by drawing astraight line through the points can be reduced by applying themethod of least squares.

11.7 For each series of tests, calculate the arithmetic meanof all values obtained and report it as the “average value” forthe particular property in question.

11.8 Calculate the standard deviation (estimated) as followsand report it to two significant figures:

s 5 =~(X 2 2 nX̄2! / ~n 2 1! (3)

where:s = estimated standard deviation,X = value of single observation,n = number of observations, andX̄ = arithmetic mean of the set of observations.

11.9 See Annex A1 for information on toe compensation.

12. Report

12.1 Report the following information:12.1.1 Complete identification of the material tested, includ-

ing type, source, manufacturer’s code numbers, form, principaldimensions, previous history, etc.,

12.1.2 Method of preparing test specimens,12.1.3 Type of test specimen and dimensions,

FIG. 4 Plot of Strains Versus Load for Determination of Poisson’s Ratio

TABLE 5 Tensile Strength at Break, 10 3 psi, for EightLaboratories, Five Materials A

Mean Sr SR Ir IR

Polypropylene 2.97 1.54 1.65 4.37 4.66Cellulose acetate butyrate 4.82 0.058 0.180 0.164 0.509Acrylic 9.09 0.452 0.751 1.27 2.13Glass-reinforced polyester 20.8 0.233 0.437 0.659 1.24Glass-reinforced nylon 23.6 0.277 0.698 0.784 1.98

A Tensile strength and elongation at break values obtained for unreinforcedpropylene plastics generally are highly variable due to inconsistencies in neckingor “drawing” of the center section of the test bar. Since tensile strength andelongation at yield are more reproducible and relate in most cases to the practicalusefulness of a molded part, they are generally recommended for specificationpurposes.

TABLE 6 Elongation at Break, %, for Eight Laboratories, FiveMaterials A

Mean Sr SR Ir IR

Glass-reinforced polyester 3.68 0.20 2.33 0.570 6.59Glass-reinforced nylon 3.87 0.10 2.13 0.283 6.03Acrylic 13.2 2.05 3.65 5.80 10.3Cellulose acetate butyrate 14.1 1.87 6.62 5.29 18.7Polypropylene 293.0 50.9 119.0 144.0 337.0

A Tensile strength and elongation at break values obtained for unreinforcedpropylene plastics generally are highly variable due to inconsistencies in neckingor “drawing” of the center section of the test bar. Since tensile strength andelongation at yield are more reproducible and relate in most cases to the practicalusefulness of a molded part, they are generally recommended for specificationpurposes.

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12.1.4 Conditioning procedure used,12.1.5 Atmospheric conditions in test room,12.1.6 Number of specimens tested,12.1.7 Speed of testing,12.1.8 Classification of extensometers used. A description

of measuring technique and calculations employed instead of aminimum Class-C extensometer system,

12.1.9 Tensile strength at yield or break, average value, andstandard deviation,

12.1.10 Tensile stress at yield or break, if applicable,average value, and standard deviation,

12.1.11 Percent elongation at yield or break, or both, asapplicable, average value, and standard deviation,

12.1.12 Modulus of elasticity, average value, and standarddeviation,

12.1.13 Date of test, and12.1.14 Revision date of Test Method D 638.

13. Precision and Bias12

13.1 Precision—Tables 2-6 are based on a round-robin testconducted in 1984, involving five materials tested by eightlaboratories using the Type I specimen, all of nominal 0.125-in.thickness. Each test result was based on five individualdeterminations. Each laboratory obtained two test results foreach material.

13.1.1 Tables 7-10 are based on a round-robin test con-ducted by the polyolefin subcommittee in 1988, involving eightpolyethylene materials tested in ten laboratories. For eachmaterial, all samples were molded at one source, but the

individual specimens were prepared at the laboratories thattested them. Each test result was the average of five individualdeterminations. Each laboratory obtained three test results foreach material. Data from some laboratories could not be usedfor various reasons, and this is noted in each table.

13.1.2 In Tables 2-10, for the materials indicated, and fortest results that derived from testing five specimens:

13.1.2.1Sr is the within-laboratory standard deviation ofthe average;Ir = 2.83Sr. (See 13.1.2.3 for application ofIr.)

13.1.2.2SR is the between-laboratory standard deviation ofthe average;IR = 2.83SR. (See 13.1.2.4 for application ofIR.)

13.1.2.3Repeatability—In comparing two test results forthe same material, obtained by the same operator using thesame equipment on the same day, those test results should bejudged not equivalent if they differ by more than theIr valuefor that material and condition.

13.1.2.4Reproducibility—In comparing two test results forthe same material, obtained by different operators using differ-ent equipment on different days, those test results should bejudged not equivalent if they differ by more than theIR valuefor that material and condition. (This applies between differentlaboratories or between different equipment within the samelaboratory.)

13.1.2.5 Any judgment in accordance with 13.1.2.3 and13.1.2.4 will have an approximate 95 % (0.95) probability ofbeing correct.

13.1.2.6 Other formulations may give somewhat differentresults.

13.1.2.7 For further information on the methodology used inthis section, see Practice E 691.

13.1.2.8 The precision of this test method is very dependentupon the uniformity of specimen preparation, standard prac-tices for which are covered in other documents.

13.2 Bias—There are no recognized standards on which tobase an estimate of bias for this test method.

12 Supporting data are available from ASTM Headquarters. Request RR:D20-1125 for the 1984 round robin and RR:D20-1170 for the 1988 round robin.

TABLE 7 Tensile Yield Strength, for Ten Laboratories, EightMaterials

MaterialTest

Speed,in./min

Values Expressed in psi Units

Average Sr SR r R

LDPE 20 1544 52.4 64.0 146.6 179.3LDPE 20 1894 53.1 61.2 148.7 171.3LLDPE 20 1879 74.2 99.9 207.8 279.7LLDPE 20 1791 49.2 75.8 137.9 212.3LLDPE 20 2900 55.5 87.9 155.4 246.1LLDPE 20 1730 63.9 96.0 178.9 268.7HDPE 2 4101 196.1 371.9 549.1 1041.3HDPE 2 3523 175.9 478.0 492.4 1338.5

TABLE 8 Tensile Yield Elongation, for Eight Laboratories, EightMaterials

MaterialTest

Speed,in./min

Values Expressed in Percent Units

Average Sr SR r R

LDPE 20 17.0 1.26 3.16 3.52 8.84LDPE 20 14.6 1.02 2.38 2.86 6.67LLDPE 20 15.7 1.37 2.85 3.85 7.97LLDPE 20 16.6 1.59 3.30 4.46 9.24LLDPE 20 11.7 1.27 2.88 3.56 8.08LLDPE 20 15.2 1.27 2.59 3.55 7.25HDPE 2 9.27 1.40 2.84 3.91 7.94HDPE 2 9.63 1.23 2.75 3.45 7.71

TABLE 9 Tensile Break Strength, for Nine Laboratories, SixMaterials

MaterialTest

Speed,in./min

Values Expressed in psi Units

Average Sr SR r R

LDPE 20 1592 52.3 74.9 146.4 209.7LDPE 20 1750 66.6 102.9 186.4 288.1LLDPE 20 4379 127.1 219.0 355.8 613.3LLDPE 20 2840 78.6 143.5 220.2 401.8LLDPE 20 1679 34.3 47.0 95.96 131.6LLDPE 20 2660 119.1 166.3 333.6 465.6

TABLE 10 Tensile Break Elongation, for Nine Laboratories, SixMaterials

MaterialTest

Speed,in./min

Values Expressed in Percent Units

Average Sr SR r R

LDPE 20 567 31.5 59.5 88.2 166.6LDPE 20 569 61.5 89.2 172.3 249.7LLDPE 20 890 25.7 113.8 71.9 318.7LLDPE 20 64.4 6.68 11.7 18.7 32.6LLDPE 20 803 25.7 104.4 71.9 292.5LLDPE 20 782 41.6 96.7 116.6 270.8

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14. Keywords

14.1 modulus of elasticity; percent elongation; plastics;tensile properties; tensile strength

ANNEXES

(Mandatory Information)

A1. TOE COMPENSATION

A1.1 In a typical stress-strain curve (Fig. A1.1) there is atoe region,AC, that does not represent a property of thematerial. It is an artifact caused by a takeup of slack andalignment or seating of the specimen. In order to obtain correctvalues of such parameters as modulus, strain, and offset yieldpoint, this artifact must be compensated for to give thecorrected zero point on the strain or extension axis.

A1.2 In the case of a material exhibiting a region ofHookean (linear) behavior (Fig. A1.1), a continuation of thelinear (CD) region of the curve is constructed through thezero-stress axis. This intersection (B) is the corrected zero-strain point from which all extensions or strains must bemeasured, including the yield offset (BE), if applicable. The

elastic modulus can be determined by dividing the stress at anypoint along the lineCD (or its extension) by the strain at thesame point (measured from PointB, defined as zero-strain).

A1.3 In the case of a material that does not exhibit anylinear region (Fig. A1.2), the same kind of toe correction of thezero-strain point can be made by constructing a tangent to themaximum slope at the inflection point (H8). This is extended tointersect the strain axis at PointB8, the corrected zero-strainpoint. Using PointB8 as zero strain, the stress at any point (G8)on the curve can be divided by the strain at that point to obtaina secant modulus (slope of LineB8 G8). For those materialswith no linear region, any attempt to use the tangent throughthe inflection point as a basis for determination of an offsetyield point may result in unacceptable error.

NOTE 1—Some chart recorders plot the mirror image of this graph.FIG. A1.1 Material with Hookean Region

NOTE 1—Some chart recorders plot the mirror image of this graph.FIG. A1.2 Material with No Hookean Region

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A2. DEFINITIONS OF TERMS AND SYMBOLS RELATING TO TENSION TESTING OF PLASTICS

A2.1 elastic limit—the greatest stress which a material iscapable of sustaining without any permanent strain remainingupon complete release of the stress. It is expressed in force perunit area, usually pounds-force per square inch (megapascals).

NOTE A2.1—Measured values of proportional limit and elastic limitvary greatly with the sensitivity and accuracy of the testing equipment,eccentricity of loading, the scale to which the stress-strain diagram isplotted, and other factors. Consequently, these values are usually replacedby yield strength.

A2.2 elongation—the increase in length produced in thegage length of the test specimen by a tensile load. It isexpressed in units of length, usually inches (millimetres). (Alsoknown asextension.)

NOTE A2.2—Elongation and strain values are valid only in cases whereuniformity of specimen behavior within the gage length is present. In thecase of materials exhibiting necking phenomena, such values are only ofqualitative utility after attainment of yield point. This is due to inability toensure that necking will encompass the entire length between the gagemarks prior to specimen failure.

A2.3 gage length—the original length of that portion of thespecimen over which strain or change in length is determined.

A2.4 modulus of elasticity—the ratio of stress (nominal) tocorresponding strain below the proportional limit of a material.It is expressed in force per unit area, usually megapascals(pounds-force per square inch). (Also known aselastic modu-lus or Young’s modulus).

NOTE A2.3—The stress-strain relations of many plastics do not con-form to Hooke’s law throughout the elastic range but deviate therefromeven at stresses well below the elastic limit. For such materials the slopeof the tangent to the stress-strain curve at a low stress is usually taken asthe modulus of elasticity. Since the existence of a true proportional limitin plastics is debatable, the propriety of applying the term “modulus ofelasticity” to describe the stiffness or rigidity of a plastic has beenseriously questioned. The exact stress-strain characteristics of plasticmaterials are very dependent on such factors as rate of stressing,temperature, previous specimen history, etc. However, such a value isuseful if its arbitrary nature and dependence on time, temperature, andother factors are realized.

A2.5 necking—the localized reduction in cross sectionwhich may occur in a material under tensile stress.

A2.6 offset yield strength—the stress at which the strainexceeds by a specified amount (the offset) an extension of theinitial proportional portion of the stress-strain curve. It isexpressed in force per unit area, usually megapascals (pounds-force per square inch).

NOTE A2.4—This measurement is useful for materials whose stress-strain curve in the yield range is of gradual curvature. The offset yieldstrength can be derived from a stress-strain curve as follows (Fig. A2.1):

On the strain axis lay offOM equal to the specified offset.Draw OA tangent to the initial straight-line portion of the stress-strain

curve.ThroughM draw a lineMN parallel toOAand locate the intersection of

MN with the stress-strain curve.

The stress at the point of intersectionr is the “offset yield strength.” Thespecified value of the offset must be stated as a percent of the original gagelength in conjunction with the strength value.Example:0.1 % offset yieldstrength = ... MPa (psi), or yield strength at 0.1 % offset ... MPa (psi).

A2.7 percent elongation—the elongation of a test specimenexpressed as a percent of the gage length.

A2.8 percent elongation at break and yield:

A2.8.1 percent elongation at breakthe percent elongation at the moment of rupture of the test

specimen.A2.8.2 percent elongation at yieldthe percent elongation at the moment the yield point (A2.21)

is attained in the test specimen.

A2.9 percent reduction of area (nominal)—the differencebetween the original cross-sectional area measured at the pointof rupture after breaking and after all retraction has ceased,expressed as a percent of the original area.

A2.10 percent reduction of area (true)—the differencebetween the original cross-sectional area of the test specimenand the minimum cross-sectional area within the gage bound-aries prevailing at the moment of rupture, expressed as apercentage of the original area.

A2.11 proportional limit—the greatest stress which amaterial is capable of sustaining without any deviation fromproportionality of stress to strain (Hooke’s law). It is expressedin force per unit area, usually megapascals (pounds-force persquare inch).

A2.12 rate of loading—the change in tensile load carriedby the specimen per unit time. It is expressed in force per unittime, usually newtons (pounds-force) per minute. The initialrate of loading can be calculated from the initial slope of theload versus time diagram.

A2.13 rate of straining—the change in tensile strain perunit time. It is expressed either as strain per unit time, usually

FIG. A2.1 Offset Yield Strength

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metres per metre (inches per inch) per minute, or percentelongation per unit time, usually percent elongation per minute.The initial rate of straining can be calculated from the initialslope of the tensile strain versus time diagram.

NOTE A2.5—The initial rate of straining is synonymous with the rate ofcrosshead movement divided by the initial distance between crossheadsonly in a machine with constant rate of crosshead movement and when thespecimen has a uniform original cross section, does not “neck down,” anddoes not slip in the jaws.

A2.14 rate of stressing (nominal)—the change in tensilestress (nominal) per unit time. It is expressed in force per unitarea per unit time, usually megapascals (pounds-force persquare inch) per minute. The initial rate of stressing can becalculated from the initial slope of the tensile stress (nominal)versus time diagram.

NOTE A2.6—The initial rate of stressing as determined in this mannerhas only limited physical significance. It does, however, roughly describethe average rate at which the initial stress (nominal) carried by the testspecimen is applied. It is affected by the elasticity and flow characteristicsof the materials being tested. At the yield point, the rate of stressing (true)may continue to have a positive value if the cross-sectional area isdecreasing.

A2.15 secant modulus—the ratio of stress (nominal) tocorresponding strain at any specified point on the stress-straincurve. It is expressed in force per unit area, usually megapas-cals (pounds-force per square inch), and reported together withthe specified stress or strain.

NOTE A2.7—This measurement is usually employed in place of modu-lus of elasticity in the case of materials whose stress-strain diagram doesnot demonstrate proportionality of stress to strain.

A2.16 strain—the ratio of the elongation to the gage lengthof the test specimen, that is, the change in length per unit oforiginal length. It is expressed as a dimensionless ratio.

A2.17 tensile strength (nominal)—the maximum tensilestress (nominal) sustained by the specimen during a tensiontest. When the maximum stress occurs at the yield point(A2.21), it shall be designated tensile strength at yield. Whenthe maximum stress occurs at break, it shall be designatedtensile strength at break.

A2.18 tensile stress (nominal)—the tensile load per unitarea of minimum original cross section, within the gageboundaries, carried by the test specimen at any given moment.It is expressed in force per unit area, usually megapascals(pounds-force per square inch).

NOTE A2.8—The expression of tensile properties in terms of theminimum original cross section is almost universally used in practice. Inthe case of materials exhibiting high extensibility or necking, or both(A2.15), nominal stress calculations may not be meaningful beyond theyield point (A2.21) due to the extensive reduction in cross-sectional areathat ensues. Under some circumstances it may be desirable to express thetensile properties per unit of minimum prevailing cross section. Theseproperties are called true tensile properties (that is, true tensile stress, etc.).

A2.19 tensile stress-strain curve—a diagram in whichvalues of tensile stress are plotted as ordinates against corre-sponding values of tensile strain as abscissas.

A2.20 true strain(see Fig. A2.2) is defined by the follow-ing equation foreT:

eT 5 *Lo

LdL/L 5 ln L/Lo (A2.1)

where:dL = increment of elongation when the distance between

the gage marks isL,Lo = original distance between gage marks, andL = distance between gage marks at any time.

A2.21 yield point—the first point on the stress-strain curveat which an increase in strain occurs without an increase instress (Fig. A2.2).

NOTE A2.9—Only materials whose stress-strain curves exhibit a pointof zero slope may be considered as having a yield point.

NOTE A2.10—Some materials exhibit a distinct “break” or discontinu-ity in the stress-strain curve in the elastic region. This break is not a yieldpoint by definition. However, this point may prove useful for materialcharacterization in some cases.

A2.22 yield strength—the stress at which a material exhib-its a specified limiting deviation from the proportionality ofstress to strain. Unless otherwise specified, this stress will bethe stress at the yield point and when expressed in relation tothe tensile strength shall be designated either tensile strength atyield or tensile stress at yield as required in A2.17 (Fig. A2.3).(Seeoffset yield strength.)

A2.23 Symbols—The following symbols may be used forthe above terms:

Symbol TermW Load

DW Increment of loadL Distance between gage marks at any time

Lo Original distance between gage marksLu Distance between gage marks at moment of ruptureDL Increment of distance between gage marks = elongation

A Minimum cross-sectional area at any timeAo Original cross-sectional areaDA Increment of cross-sectional areaAu Cross-sectional area at point of rupture measured after

breaking specimenAT Cross-sectional area at point of rupture, measured at the

moment of rupturet Time

Dt Increment of times Tensile stress

Ds Increment of stresssT True tensile stresssU Tensile strength at break (nominal)

sUT Tensile strength at break (true)e Strain

De Increment of straineU Total strain, at breakeT True strain

%El Percentage elongationY.P. Yield point

E Modulus of elasticity

A2.24 Relations between these various terms may bedefined as follows:

FIG. A2.2 Illustration of True Strain Equation

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s = W/Ao

sT = W/A

sU = W/Ao (where W is breaking load)sUT = W/AT (where W is breaking load)

e = DL/Lo = (L − Lo)/Lo

eU = (Lu − Lo)/Lo

eT = *Lo

L dL/L 5 ln L/Lo%El = [(L − Lo)/Lo] 3 100 = e 3 100

Percent reduction of area (nominal) = [(Ao − Au)/Ao] 3 100Percent reduction of area (true) = [(Ao − AT)/Ao] 3 100Rate of loading = DW/DtRate of stressing (nominal) = Ds/D = (DW]/Ao)/DtRate of straining = De/Dt = (DL/Lo)Dt

For the case where the volume of the test specimen does notchange during the test, the following three relations hold:

sT 5 s~1 1 e! 5 sL/Lo (A2.2)

sUT 5 sU ~1 1 eU! 5 sU Lu /Lo

A 5 Ao /~1 1 e!

SUMMARY OF CHANGES

This section identifies the location of selected changes to this test method. For the convenience of the user,Committee D20 has highlighted those changes that may impact the use of this test method. This section may alsoinclude descriptions of the changes or reasons for the changes, or both.

D 638–02:(1) Revised 9.1 and 9.2.D 638–01:(1) Modified 7.3 regarding conditions for specimen discard.D 638–00:(1) Added 11.1 and renumbered subsequent sections.D 638–99:(1) Added and clarified extensometer classification require-ments.

D 638–98:

(1) Revised 10.3 and added 12.1.8 to clarify extensometerusage.

(2) Added 12.1.14.

(3) Replaced reference to Test Methods D 374 with TestMethod D 5947 in 2.1 and 5.3.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.

FIG. A2.3 Tensile Designations

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This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or [email protected] (e-mail); or through the ASTM website(www.astm.org).

D 638

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Standard Test Methods forFlexural Properties of Unreinforced and Reinforced Plasticsand Electrical Insulating Materials 1


This standard has been approved for use by agencies of the Department of Defense.

1. Scope *

1.1 These test methods cover the determination of flexuralproperties of unreinforced and reinforced plastics, includinghigh-modulus composites and electrical insulating materials inthe form of rectangular bars molded directly or cut from sheets,plates, or molded shapes. These test methods are generallyapplicable to both rigid and semirigid materials. However,flexural strength cannot be determined for those materials thatdo not break or that do not fail in the outer surface of the testspecimen within the 5.0 % strain limit of these test methods.These test methods utilize a three-point loading system appliedto a simply supported beam. A four-point loading systemmethod can be found in Test Method D 6272.

1.1.1 Procedure A, designed principally for materials thatbreak at comparatively small deflections.

1.1.2 Procedure B, designed particularly for those materialsthat undergo large deflections during testing.

1.1.3 Procedure A shall be used for measurement of flexuralproperties, particularly flexural modulus, unless the materialspecification states otherwise. Procedure B may be used formeasurement of flexural strength only. Tangent modulus dataobtained by Procedure A tends to exhibit lower standarddeviations than comparable data obtained by means of Proce-dure B.

1.2 Comparative tests may be run in accordance with eitherprocedure, provided that the procedure is found satisfactory forthe material being tested.

1.3 The values stated in SI units are to be regarded as thestandard. The values provided in parentheses are for informa-tion only.


NOTE 1—These test methods are not technically equivalent to ISO 178.


2.1 ASTM Standards:D 618 Practice for Conditioning Plastics for Testing2

D 638 Test Method for Tensile Properties of Plastics2



D 5947 Test Methods for Physical Dimensions of SolidPlastic Specimens4

D 6272 Test Method for Flexural Properties of Unrein-forced and Reinforced Plastics and Electrical InsulatingMaterials by Four-Point Bending4

E 4 Practices for Force Verification of Testing Machines5

E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method6

3. Terminology

3.1 Definitions—Definitions of terms applying to these testmethods appear in Terminology D 883 and Annex A1 of TestMethod D 638.

4. Summary of Test Method

4.1 A bar of rectangular cross section rests on two supportsand is loaded by means of a loading nose midway between thesupports (see Fig. 1). A support span-to-depth ratio of 16:1shall be used unless there is reason to suspect that a largerspan-to-depth ratio may be required, as may be the case forcertain laminated materials (see Section 7 and Note 8 forguidance).

4.2 The specimen is deflected until rupture occurs in theouter surface of the test specimen or until a maximum strain(see 12.7) of 5.0 % is reached, whichever occurs first.

4.3 Procedure A employs a strain rate of 0.01 mm/mm/min(0.01 in./in./min) and is the preferred procedure for this testmethod, while Procedure B employs a strain rate of 0.10mm/mm/min (0.10 in./in./min).

1 These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.10 on MechanicalProperties.

Current edition approved April 10, 2002. Published June 2002. Originallypublished as D 790 – 70. Last previous edition D 790 – 00.

2 Annual Book of ASTM Standards, Vol 08.01.3 Annual Book of ASTM Standards, Vol 08.02.4 Annual Book of ASTM Standards, Vol 08.03.5 Annual Book of ASTM Standards, Vol 03.01.6 Annual Book of ASTM Standards, Vol 14.02.

1




5.1 Flexural properties as determined by these test methodsare especially useful for quality control and specificationpurposes.

5.2 Materials that do not fail by the maximum strainallowed under these test methods (3-point bend) may be moresuited to a 4-point bend test. The basic difference between thetwo test methods is in the location of the maximum bendingmoment and maximum axial fiber stresses. The maximum axialfiber stresses occur on a line under the loading nose in 3-pointbending and over the area between the loading noses in 4-pointbending.

5.3 Flexural properties may vary with specimen depth,temperature, atmospheric conditions, and the difference in rateof straining as specified in Procedures A and B (see also Note8).

5.4 Before proceeding with these test methods, referenceshould be made to the specification of the material being tested.Any test specimen preparation, conditioning, dimensions, ortesting parameters, or combination thereof, covered in thematerials specification shall take precedence over those men-tioned in these test methods. If there are no material specifi-cations, then the default conditions apply. Table 1 in Classifi-cation System D 4000 lists the ASTM materials standards thatcurrently exist for plastics.

6. Apparatus

6.1 Testing Machine— A properly calibrated testing ma-chine that can be operated at constant rates of crosshead motionover the range indicated, and in which the error in the loadmeasuring system shall not exceed61 % of the maximum loadexpected to be measured. It shall be equipped with a deflectionmeasuring device. The stiffness of the testing machine shall besuch that the total elastic deformation of the system does notexceed 1 % of the total deflection of the test specimen during

testing, or appropriate corrections shall be made. The loadindicating mechanism shall be essentially free from inertial lagat the crosshead rate used. The accuracy of the testing machineshall be verified in accordance with Practices E 4.

6.2 Loading Noses and Supports—The loading nose andsupports shall have cylindrical surfaces. In order to avoidexcessive indentation, or failure due to stress concentrationdirectly under the loading nose, the radii of the loading noseand supports shall be 5.06 0.1 mm (0.1976 0.004 in.) unlessotherwise specified or agreed upon between the interestedclients. When other loading noses and supports are used theymust comply with the following requirements: they shall havea minimum radius of 3.2 mm (1⁄8 in.) for all specimens, and forspecimens 3.2 mm or greater in depth, the radius of thesupports may be up to 1.6 times the specimen depth. They shallbe this large if significant indentation or compressive failureoccurs. The arc of the loading nose in contact with thespecimen shall be sufficiently large to prevent contact of thespecimen with the sides of the nose (see Fig. 1). The maximumradius of the loading nose shall be no more than 4 times thespecimen depth.

NOTE 2—Test data have shown that the loading nose and supportdimensions can influence the flexural modulus and flexural strengthvalues. The loading nose dimension has the greater influence. Dimensionsof the loading nose and supports must be specified in the materialspecification.

6.3 Micrometers— Suitable micrometers for measuring thewidth and thickness of the test specimen to an incrementaldiscrimination of at least 0.025 mm (0.001 in.) should be used.All width and thickness measurements of rigid and semirigidplastics may be measured with a hand micrometer with ratchet.A suitable instrument for measuring the thickness of nonrigidtest specimens shall have: a contact measuring pressure of256 2.5 kPa (3.66 0.36 psi), a movable circular contact foot6.356 0.025 mm (0.2506 0.001 in.) in diameter and a lowerfixed anvil large enough to extend beyond the contact foot inall directions and being parallel to the contact foot within 0.005mm (0.002 in.) over the entire foot area. Flatness of foot andanvil shall conform to the portion of the Calibration section ofTest Methods D 5947.

7. Test Specimens

7.1 The specimens may be cut from sheets, plates, or

NOTE—(a) Minimum radius = 3.2 mm (1⁄8 in.). (b) Maximum radiussupports 1.6 times specimen depth; maximum radius loading nose = 4times specimen depth.

FIG. 1 Allowable Range of Loading Nose and Support Radii

TABLE 1 Flexural Strength

Material Mean, 103 psi

Values Expressed in Units of %of 103 psi

VrA VR

B rC RD

ABS 9.99 1.59 6.05 4.44 17.2DAP thermoset 14.3 6.58 6.58 18.6 18.6Cast acrylic 16.3 1.67 11.3 4.73 32.0GR polyester 19.5 1.43 2.14 4.05 6.08GR polycarbonate 21.0 5.16 6.05 14.6 17.1SMC 26.0 4.76 7.19 13.5 20.4A Vr = within-laboratory coefficient of variation for the indicated material. It is

obtained by first pooling the within-laboratory standard deviations of the testresults from all of the participating laboratories: Sr = [[(s1)2 + (s2)2 . . . + ( sn)2]/n]1/2 then Vr = (Sr divided by the overall average for the material) 3 100.

B Vr = between-laboratory reproducibility, expressed as the coefficient of varia-tion: SR = {Sr

2 + SL2}1/2 where SL is the standard deviation of laboratory means.

Then: VR = (S R divided by the overall average for the material) 3 100.C r = within-laboratory critical interval between two test results = 2.8 3 Vr.D R = between-laboratory critical interval between two test results = 2.8 3 VR.

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molded shapes, or may be molded to the desired finisheddimensions. The actual dimensions used in Section 4.2, Cal-culation, shall be measured in accordance with Test MethodsD 5947.

NOTE 3—Any necessary polishing of specimens shall be done only inthe lengthwise direction of the specimen.

7.2 Sheet Materials (Except Laminated Thermosetting Ma-terials and Certain Materials Used for Electrical Insulation,Including Vulcanized Fiber and Glass Bonded Mica):

7.2.1 Materials 1.6 mm (1⁄16 in.) or Greater in Thickness—For flatwise tests, the depth of the specimen shall be thethickness of the material. For edgewise tests, the width of thespecimen shall be the thickness of the sheet, and the depth shallnot exceed the width (see Notes 4 and 5). For all tests, thesupport span shall be 16 (tolerance61) times the depth of thebeam. Specimen width shall not exceed one fourth of thesupport span for specimens greater than 3.2 mm (1⁄8 in.) indepth. Specimens 3.2 mm or less in depth shall be 12.7 mm (1⁄2in.) in width. The specimen shall be long enough to allow foroverhanging on each end of at least 10 % of the support span,but in no case less than 6.4 mm (1⁄4 in.) on each end. Overhangshall be sufficient to prevent the specimen from slippingthrough the supports.

NOTE 4—Whenever possible, the original surface of the sheet shall beunaltered. However, where testing machine limitations make it impossibleto follow the above criterion on the unaltered sheet, one or both surfacesshall be machined to provide the desired dimensions, and the location ofthe specimens with reference to the total depth shall be noted. The valueobtained on specimens with machined surfaces may differ from thoseobtained on specimens with original surfaces. Consequently, any specifi-cations for flexural properties on thicker sheets must state whether theoriginal surfaces are to be retained or not. When only one surface wasmachined, it must be stated whether the machined surface was on thetension or compression side of the beam.

NOTE 5—Edgewise tests are not applicable for sheets that are so thinthat specimens meeting these requirements cannot be cut. If specimendepth exceeds the width, buckling may occur.

7.2.2 Materials Less than 1.6 mm (1⁄16 in.) in Thickness—The specimen shall be 50.8 mm (2 in.) long by 12.7 mm (1⁄2 in.)wide, tested flatwise on a 25.4-mm (1-in.) support span.

NOTE 6—Use of the formulas for simple beams cited in these testmethods for calculating results presumes that beam width is small incomparison with the support span. Therefore, the formulas do not applyrigorously to these dimensions.

NOTE 7—Where machine sensitivity is such that specimens of thesedimensions cannot be measured, wider specimens or shorter supportspans, or both, may be used, provided the support span-to-depth ratio is atleast 14 to 1. All dimensions must be stated in the report (see also Note 6).

7.3 Laminated Thermosetting Materials and Sheet andPlate Materials Used for Electrical Insulation, IncludingVulcanized Fiber and Glass-Bonded Mica—For paper-baseand fabric-base grades over 25.4 mm (1 in.) in nominalthickness, the specimens shall be machined on both surfaces toa depth of 25.4 mm. For glass-base and nylon-base grades,specimens over 12.7 mm (1⁄2 in.) in nominal depth shall bemachined on both surfaces to a depth of 12.7 mm. The supportspan-to-depth ratio shall be chosen such that failures occur inthe outer fibers of the specimens, due only to the bendingmoment (see Note 8). Therefore, a ratio larger than 16:1 may

be necessary (32:1 or 40:1 are recommended). When laminatedmaterials exhibit low compressive strength perpendicular to thelaminations, they shall be loaded with a large radius loadingnose (up to four times the specimen depth to prevent prematuredamage to the outer fibers.

7.4 Molding Materials (Thermoplastics and Thermosets)—The recommended specimen for molding materials is 127 by12.7 by 3.2 mm (5 by1⁄2by 1⁄8 in.) tested flatwise on a supportspan, resulting in a support span-to-depth ratio of 16 (tolerance61). Thicker specimens should be avoided if they exhibitsignificant shrink marks or bubbles when molded.

7.5 High-Strength Reinforced Composites, Including HighlyOrthotropic Laminates—The span-to-depth ratio shall be cho-sen such that failure occurs in the outer fibers of the specimensand is due only to the bending moment (see Note 8). Aspan-to-depth ratio larger than 16:1 may be necessary (32:1 or40:1 are recommended). For some highly anisotropic compos-ites, shear deformation can significantly influence modulusmeasurements, even at span-to-depth ratios as high as 40:1.Hence, for these materials, an increase in the span-to-depthratio to 60:1 is recommended to eliminate shear effects whenmodulus data are required, it should also be noted that theflexural modulus of highly anisotropic laminates is a strongfunction of ply-stacking sequence and will not necessarilycorrelate with tensile modulus, which is not stacking-sequencedependent.

NOTE 8—As a general rule, support span-to-depth ratios of 16:1 aresatisfactory when the ratio of the tensile strength to shear strength is lessthan 8 to 1, but the support span-to-depth ratio must be increased forcomposite laminates having relatively low shear strength in the plane ofthe laminate and relatively high tensile strength parallel to the supportspan.

8. Number of Test Specimens

8.1 Test at least five specimens for each sample in the caseof isotropic materials or molded specimens.

8.2 For each sample of anisotropic material in sheet form,test at least five specimens for each of the following conditions.Recommended conditions are flatwise and edgewise tests onspecimens cut in lengthwise and crosswise directions of thesheet. For the purposes of this test, “lengthwise” designates theprincipal axis of anisotropy and shall be interpreted to mean thedirection of the sheet known to be stronger in flexure. “Cross-wise” indicates the sheet direction known to be the weaker inflexure and shall be at 90° to the lengthwise direction.

9. Conditioning

9.1 Conditioning—Condition the test specimens at 2362°C (73.46 3.6°F) and 506 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D 618 unless otherwise specified by contract or therelevant ASTM material specification. Reference pre-test con-ditioning, to settle disagreements, shall apply tolerances of61°C (1.8°F) and62 % relative humidity.

9.2 Test Conditions—Conduct the tests at 236 2°C (73.463.6°F) and 506 5 % relative humidity unless otherwisespecified by contract or the relevant ASTM material specifica-tion. Reference testing conditions, to settle disagreements,

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shall apply tolerances of61°C (1.8°F) and62 % relativehumidity.

10. Procedure

10.1 Procedure A:10.1.1 Use an untested specimen for each measurement.

Measure the width and depth of the specimen to the nearest0.03 mm (0.001 in.) at the center of the support span. Forspecimens less than 2.54 mm (0.100 in.) in depth, measure thedepth to the nearest 0.003 mm (0.0005 in.). These measure-ments shall be made in accordance with Test Methods D 5947.

10.1.2 Determine the support span to be used as described inSection 7 and set the support span to within 1 % of thedetermined value.

10.1.3 For flexural fixtures that have continuously adjust-able spans, measure the span accurately to the nearest 0.1 mm(0.004 in.) for spans less than 63 mm (2.5 in.) and to the nearest0.3 mm (0.012 in.) for spans greater than or equal to 63 mm(2.5 in.). Use the actual measured span for all calculations. Forflexural fixtures that have fixed machined span positions, verifythe span distance the same as for adjustable spans at eachmachined position. This distance becomes the span for thatposition and is used for calculations applicable to all subse-quent tests conducted at that position. See Annex A2 forinformation on the determination of and setting of the span.

10.1.4 Calculate the rate of crosshead motion as follows andset the machine for the rate of crosshead motion as calculatedby Eq 1:

R5 ZL 2/6d (1)

where:R = rate of crosshead motion, mm (in.)/min,L = support span, mm (in.),d = depth of beam, mm (in.), andZ = rate of straining of the outer fiber, mm/mm/min (in./

in./min). Z shall be equal to 0.01.In no case shall the actual crosshead rate differ from that

calculated using Eq 1, by more than610 %.10.1.5 Align the loading nose and supports so that the axes

of the cylindrical surfaces are parallel and the loading nose ismidway between the supports. The parallelism of the apparatusmay be checked by means of a plate with parallel grooves intowhich the loading nose and supports will fit when properlyaligned (see A2.3). Center the specimen on the supports, withthe long axis of the specimen perpendicular to the loading noseand supports.

10.1.6 Apply the load to the specimen at the specifiedcrosshead rate, and take simultaneous load-deflection data.Measure deflection either by a gage under the specimen incontact with it at the center of the support span, the gage beingmounted stationary relative to the specimen supports, or bymeasurement of the motion of the loading nose relative to thesupports. Load-deflection curves may be plotted to determinethe flexural strength, chord or secant modulus or the tangentmodulus of elasticity, and the total work as measured by thearea under the load-deflection curve. Perform the necessary toecompensation (see Annex A1) to correct for seating andindentation of the specimen and deflections in the machine.

10.1.7 Terminate the test when the maximum strain in the

outer surface of the test specimen has reached 0.05 mm/mm(in./in.) or at break if break occurs prior to reaching themaximum strain (Notes 9 and 10). The deflection at which thisstrain will occur may be calculated by lettingr equal 0.05mm/mm (in./in.) in Eq 2:

D 5 rL2/6d (2)

where:D = midspan deflection, mm (in.),r = strain, mm/mm (in./in.),L = support span, mm (in.), andd = depth of beam, mm (in.).

NOTE 9—For some materials that do not yield or break within the 5 %strain limit when tested by Procedure A, the increased strain rate allowedby Procedure B (see 10.2) may induce the specimen to yield or break, orboth, within the required 5 % strain limit.

NOTE 10—Beyond 5 % strain, this test method is not applicable. Someother mechanical property might be more relevant to characterize mate-rials that neither yield nor break by either Procedure A or Procedure Bwithin the 5 % strain limit (for example, Test Method D 638 may beconsidered).

10.2 Procedure B:10.2.1 Use an untested specimen for each measurement.10.2.2 Test conditions shall be identical to those described

in 10.1, except that the rate of straining of the outer surface ofthe test specimen shall be 0.10 mm/mm (in./in.)/min.

10.2.3 If no break has occurred in the specimen by the timethe maximum strain in the outer surface of the test specimenhas reached 0.05 mm/mm (in./in.), discontinue the test (seeNote 10).

11. Retests

11.1 Values for properties at rupture shall not be calculatedfor any specimen that breaks at some obvious, fortuitous flaw,unless such flaws constitute a variable being studied. Retestsshall be made for any specimen on which values are notcalculated.

12. Calculation

12.1 Toe compensation shall be made in accordance withAnnex A1 unless it can be shown that the toe region of thecurve is not due to the take-up of slack, seating of thespecimen, or other artifact, but rather is an authentic materialresponse.

12.2 Flexural Stress (sf)—When a homogeneous elasticmaterial is tested in flexure as a simple beam supported at twopoints and loaded at the midpoint, the maximum stress in theouter surface of the test specimen occurs at the midpoint. Thisstress may be calculated for any point on the load-deflectioncurve by means of the following equation (see Notes 11-13):

sf 5 3PL/2bd2 (3)

where:s = stress in the outer fibers at midpoint, MPa (psi),P = load at a given point on the load-deflection curve, N

(lbf),L = support span, mm (in.),b = width of beam tested, mm (in.), and

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d = depth of beam tested, mm (in.).

NOTE 11—Eq 3 applies strictly to materials for which stress is linearlyproportional to strain up to the point of rupture and for which the strainsare small. Since this is not always the case, a slight error will beintroduced if Eq 3 is used to calculate stress for materials that are not trueHookean materials. The equation is valid for obtaining comparison dataand for specification purposes, but only up to a maximum fiber strain of5 % in the outer surface of the test specimen for specimens tested by theprocedures described herein.

NOTE 12—When testing highly orthotropic laminates, the maximumstress may not always occur in the outer surface of the test specimen.7

Laminated beam theory must be applied to determine the maximumtensile stress at failure. If Eq 3 is used to calculate stress, it will yield anapparent strength based on homogeneous beam theory. This apparentstrength is highly dependent on the ply-stacking sequence of highlyorthotropic laminates.

NOTE 13—The preceding calculation is not valid if the specimen slipsexcessively between the supports.

12.3 Flexural Stress for Beams Tested at Large SupportSpans (s f)—If support span-to-depth ratios greater than 16 to1 are used such that deflections in excess of 10 % of thesupport span occur, the stress in the outer surface of thespecimen for a simple beam can be reasonably approximatedwith the following equation (see Note 14):

sf 5 ~3PL/2bd2!@1 1 6~D/L! 2 2 4~d/L!~D/L!# (4)

where:

sf, P, L, b,andd are the same as for Eq 3, andD = deflection of the centerline of the specimen at the

middle of the support span, mm (in.).

NOTE 14—When large support span-to-depth ratios are used, significantend forces are developed at the support noses which will affect themoment in a simple supported beam. Eq 4 includes additional terms thatare an approximate correction factor for the influence of these end forcesin large support span-to-depth ratio beams where relatively large deflec-tions exist.

12.4 Flexural Strength (sfM)—Maximum flexural stresssustained by the test specimen (see Note 12) during a bendingtest. It is calculated according to Eq 3 or Eq 4. Some materialsthat do not break at strains of up to 5 % may give a loaddeflection curve that shows a point at which the load does notincrease with an increase in strain, that is, a yield point (Fig. 2,Curve B),Y. The flexural strength may be calculated for thesematerials by lettingP (in Eq 3 or Eq 4) equal this point,Y.

12.5 Flexural Offset Yield Strength—Offset yield strength isthe stress at which the stress-strain curve deviates by a givenstrain (offset) from the tangent to the initial straight line portionof the stress-strain curve. The value of the offset must be givenwhenever this property is calculated.

NOTE 15—This value may differ from flexural strength defined in 12.4.Both methods of calculation are described in the annex to Test MethodD 638.

12.6 Flexural Stress at Break (sfB )—Flexural stress atbreak of the test specimen during a bending test. It is calculated

according to Eq 3 or Eq 4. Some materials may give a loaddeflection curve that shows a break point,B, without a yieldpoint (Fig. 2, Curve a) in which cases fB = sfM. Othermaterials may give a yield deflection curve with both a yieldand a break point,B (Fig. 2, Curve b). The flexural stress atbreak may be calculated for these materials by lettingP (in Eq3 or Eq 4) equal this point,B.

12.7 Stress at a Given Strain—The stress in the outersurface of a test specimen at a given strain may be calculatedin accordance with Eq 3 or Eq 4 by lettingP equal the load readfrom the load-deflection curve at the deflection correspondingto the desired strain (for highly orthotropic laminates, see Note12).

12.8 Flexural Strain, ef—Nominal fractional change in thelength of an element of the outer surface of the test specimenat midspan, where the maximum strain occurs. It may becalculated for any deflection using Eq 5:

ef 5 6Dd/L2 (5)

where:ef = strain in the outer surface, mm/mm (in./in.),D = maximum deflection of the center of the beam, mm

(in.),L = support span, mm (in.), andd = depth, mm (in.).D = maximum deflection of the center of the beam, mm

(in.),L = support span, mm (in.), and

7 For a discussion of these effects, see Zweben, C., Smith, W. S., and Wardle, M.W., “Test Methods for Fiber Tensile Strength, Composite Flexural Modulus andProperties of Fabric-Reinforced Laminates, “Composite Materials: Testing andDesign (Fifth Conference), ASTM STP 674, 1979, pp. 228–262.

NOTE—Curve a: Specimen that breaks before yielding.Curve b: Specimen that yields and then breaks before the 5 % strain

limit.Curve c: Specimen that neither yields nor breaks before the 5 % strain

limit.FIG. 2 Typical Curves of Flexural Stress ( ßf) Versus Flexural

Strain ( ef)

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d = depth, mm (in.).12.9 Modulus of Elasticity:12.9.1 Tangent Modulus of Elasticity—The tangent modu-

lus of elasticity, often called the “modulus of elasticity,” is theratio, within the elastic limit, of stress to corresponding strain.It is calculated by drawing a tangent to the steepest initialstraight-line portion of the load-deflection curve and using Eq6 (for highly anisotropic composites, see Note 16).

EB 5 L3m/4bd3 (6)

where:EB = modulus of elasticity in bending, MPa (psi),L = support span, mm (in.),b = width of beam tested, mm (in.),d = depth of beam tested, mm (in.), andm = slope of the tangent to the initial straight-line portion

of the load-deflection curve, N/mm (lbf/in.) of deflec-tion.

NOTE 16—Shear deflections can seriously reduce the apparent modulusof highly anisotropic composites when they are tested at low span-to-depth ratios.7 For this reason, a span-to-depth ratio of 60 to 1 isrecommended for flexural modulus determinations on these composites.Flexural strength should be determined on a separate set of replicatespecimens at a lower span-to-depth ratio that induces tensile failure in theouter fibers of the beam along its lower face. Since the flexural modulusof highly anisotropic laminates is a critical function of ply-stackingsequence, it will not necessarily correlate with tensile modulus, which isnot stacking-sequence dependent.

12.9.2 Secant Modulus— The secant modulus is the ratio ofstress to corresponding strain at any selected point on thestress-strain curve, that is, the slope of the straight line thatjoins the origin and a selected point on the actual stress-straincurve. It shall be expressed in megapascals (pounds per squareinch). The selected point is chosen at a prespecified stress orstrain in accordance with the appropriate material specificationor by customer contract. It is calculated in accordance with Eq6 by letting m equal the slope of the secant to the load-deflection curve. The chosen stress or strain point used for thedetermination of the secant shall be reported.

12.9.3 Chord Modulus (Ef)—The chord modulus may becalculated from two discrete points on the load deflection

curve. The selected points are to be chosen at two prespecifiedstress or strain points in accordance with the appropriatematerial specification or by customer contract. The chosenstress or strain points used for the determination of the chordmodulus shall be reported. Calculate the chord modulus,Ef

using the following equation:

Ef 5 ~sf2 2 sf1!/~ef2 2 ef1! (7)

where:

sf2 andsf1 are the flexural stresses, calculated from Eq 3 orEq 4 and measured at the predefined points on the loaddeflection curve, ande f2 and

ef1 are the flexural strain values, calculated from Eq 5 andmeasured at the predetermined points on the load deflectioncurve.

12.10 Arithmetic Mean— For each series of tests, thearithmetic mean of all values obtained shall be calculated tothree significant figures and reported as the “average value” forthe particular property in question.

12.11 Standard Deviation—The standard deviation (esti-mated) shall be calculated as follows and be reported to twosignificant figures:

s 5 =~(X 2 2 nX̄2! / ~n 2 1! (8)

where:s = estimated standard deviation,X = value of single observation,n = number of observations, andX̄ = arithmetic mean of the set of observations.

13. Report

13.1 Report the following information:13.1.1 Complete identification of the material tested, includ-

ing type, source, manufacturer’s code number, form, principaldimensions, and previous history (for laminated materials,ply-stacking sequence shall be reported),

13.1.2 Direction of cutting and loading specimens, whenappropriate,

13.1.3 Conditioning procedure,13.1.4 Depth and width of specimen,13.1.5 Procedure used (A or B),13.1.6 Support span length,13.1.7 Support span-to-depth ratio if different than 16:1,13.1.8 Radius of supports and loading noses if different than

5 mm,13.1.9 Rate of crosshead motion,13.1.10 Flexural strain at any given stress, average value

and standard deviation,13.1.11 If a specimen is rejected, reason(s) for rejection,13.1.12 Tangent, secant, or chord modulus in bending,

average value, standard deviation, and the strain level(s) usedif secant or chord modulus,

13.1.13 Flexural strength (if desired), average value, andstandard deviation,

13.1.14 Stress at any given strain up to and including 5 % (ifdesired), with strain used, average value, and standard devia-tion,

13.1.15 Flexural stress at break (if desired), average value,

TABLE 2 Flexural Modulus

Material Mean, 103 psi

Values Expressed in units of %of 103 psi

VrA VR

B rC RD

ABS 338 4.79 7.69 13.6 21.8DAP thermoset 485 2.89 7.18 8.15 20.4Cast acrylic 810 13.7 16.1 38.8 45.4GR polyester 816 3.49 4.20 9.91 11.9GR polycarbonate 1790 5.52 5.52 15.6 15.6SMC 1950 10.9 13.8 30.8 39.1A Vr = within-laboratory coefficient of variation for the indicated material. It is

obtained by first pooling the within-laboratory standard deviations of the testresults from all of the participating laboratories: Sr = [[(s1)2 + ( s2)2 . . . + (sn)2]/n]1/2 then Vr = (Sr divided by the overall average for the material) 3 100.

B Vr = between-laboratory reproducibility, expressed as the coefficient of varia-tion: SR = {Sr

2 + SL2}1/2 where SL is the standard deviation of laboratory means.

Then: VR = (SR divided by the overall average for the material) 3 100.Cr = within-laboratory critical interval between two test results = 2.8 3 Vr.D R = between-laboratory critical interval between two test results = 2.8 3 VR.

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and standard deviation,13.1.16 Type of behavior, whether yielding or rupture, or

both, or other observations, occurring within the 5 % strainlimit, and

13.1.17 Date of specific version of test used.


14.1 Tables 1 and 2 are based on a round-robin testconducted in 1984, in accordance with Practice E 691, involv-ing six materials tested by six laboratories using Procedure A.For each material, all the specimens were prepared at onesource. Each “test result” was the average of five individualdeterminations. Each laboratory obtained two test results foreach material.

NOTE 17—Caution: The following explanations ofr and R (14.2-14.2.3) are intended only to present a meaningful way of considering theapproximate precision of these test methods. The data given in Tables 2and 3 should not be applied rigorously to the acceptance or rejection ofmaterials, as those data are specific to the round robin and may not berepresentative of other lots, conditions, materials, or laboratories. Users ofthese test methods should apply the principles outlined in Practice E 691to generate data specific to their laboratory and materials, or between

specific laboratories. The principles of 14.2-14.2.3 would then be valid forsuch data.

14.2 Concept of “r” and “R” in Tables 1 and 2—IfSr andSR have been calculated from a large enough body of data, andfor test results that were averages from testing five specimensfor each test result, then:

14.2.1 Repeatability— Two test results obtained within onelaboratory shall be judged not equivalent if they differ by morethan ther value for that material.r is the interval representingthe critical difference between two test results for the samematerial, obtained by the same operator using the sameequipment on the same day in the same laboratory.

14.2.2 Reproducibility— Two test results obtained by dif-ferent laboratories shall be judged not equivalent if they differby more than theR value for that material.R is the intervalrepresenting the critical difference between two test results forthe same material, obtained by different operators using differ-ent equipment in different laboratories.

14.2.3 The judgments in 14.2.1 and 14.2.2 will have anapproximately 95 % (0.95) probability of being correct.

14.3 Bias—No statement may be made about the bias ofthese test methods, as there is no standard reference material orreference test method that is applicable.

15. Keywords

15.1 flexural properties; plastics; stiffness; strength

ANNEXES


A1. TOE COMPENSATION

A1.1 In a typical stress-strain curve (see Fig. A1.1) there is a toe region,AC, that does not represent a property of thematerial. It is an artifact caused by a takeup of slack andalignment or seating of the specimen. In order to obtain correctvalues of such parameters as modulus, strain, and offset yieldpoint, this artifact must be compensated for to give thecorrected zero point on the strain or extension axis.

A1.2 In the case of a material exhibiting a region ofHookean (linear) behavior (see Fig. A1.1), a continuation ofthe linear(CD) region of the curve is constructed through thezero-stress axis. This intersection(B) is the corrected zero-strain point from which all extensions or strains must bemeasured, including the yield offset(BE), if applicable. Theelastic modulus can be determined by dividing the stress at anypoint along the LineCD (or its extension) by the strain at thesame point (measured from PointB, defined as zero-strain).

A1.3 In the case of a material that does not exhibit anylinear region (see Fig. A1.2), the same kind of toe correction ofthe zero-strain point can be made by constructing a tangent tothe maximum slope at the inflection PointH8. This is extendedto intersect the strain axis at PointB8, the corrected zero-strainpoint. Using PointB8 as zero strain, the stress at any point(G8)on the curve can be divided by the strain at that point to obtaina secant modulus (slope of LineB8 G8). For those materialswith no linear region, any attempt to use the tangent through

8 Supporting data are available from ASTM Headquarters. Request RR:D20 – 1128.

NOTE—Some chart recorders plot the mirror image of this graph.FIG. A1.1 Material with Hookean Region

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the inflection point as a basis for determination of an offset

yield point may result in unacceptable error.

A2. MEASURING AND SETTING SPAN

A2.1 For flexural fixtures that have adjustable spans, it isimportant that the span between the supports is maintainedconstant or the actual measured span is used in the calculationof stress, modulus, and strain, and the loading nose or noses arepositioned and aligned properly with respect to the supports.Some simple steps as follows can improve the repeatability ofyour results when using these adjustable span fixtures.

A2.2 Measurement of Span:

A2.2.1 This technique is needed to ensure that the correctspan, not an estimated span, is used in the calculation ofresults.

A2.2.2 Scribe a permanent line or mark at the exact centerof the support where the specimen makes complete contact.The type of mark depends on whether the supports are fixed orrotatable (see Figs. A2.1 and A2.2).

A2.2.3 Using a vernier caliper with pointed tips that isreadable to at least 0.1 mm (0.004 in.), measure the distancebetween the supports, and use this measurement of span in thecalculations.

A2.3 Setting the Span and Alignment of LoadingNose(s)—To ensure a consistent day-to-day setup of the spanand ensure the alignment and proper positioning of the loadingnose, simple jigs should be manufactured for each of thestandard setups used. An example of a jig found to be useful isshown in Fig. A2.3.

NOTE—Some chart recorders plot the mirror image of this graph.FIG. A1.2 Material with No Hookean Region

FIG. A2.1 Markings on Fixed Specimen Supports

FIG. A2.2 Markings on Rotatable Specimen Supports

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SUMMARY OF CHANGES

This section identifies the location of selected changes to these test methods. For the convenience of the user,Committee D20 has highlighted those changes that may impact the use of these test methods. This section mayalso include descriptions of the changes or reasons for the changes, or both.

D 790 – 02:(1) Revised 9.1 and 9.2.D 790 – 00:(1) Revised 12.1.D 790 – 99:(1) Revised 10.1.3.

D 790 – 98:(1) Section 4.2 was rewritten extensively to bring this standardcloser to ISO 178.(2) Fig. 2 was added to clarify flexural behaviors that may beobserved and to define what yielding and breaking behaviorslook like, as well as the appropriate place to select these pointson the stress strain curve.




FIG. A2.3 Fixture Used to Set Loading Nose and Support Spacing and Alignment

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Designation: D 256 – 00 e1 An American National Standard

Standard Test Methods forDetermining the Izod Pendulum Impact Resistance ofPlastics 1


e1 NOTE—Note 2 was editorially added in April 2002. Title of Table 1 was editorially corrected in April 2002.

1. Scope *

1.1 These test methods cover the determination of theresistance of plastics to “standardized” (see Note 1) pendulum-type hammers, mounted in “standardized” machines, in break-ing standard specimens with one pendulum swing (see Note 2).The standard tests for these test methods require specimensmade with a milled notch (see Note 3). In Test Methods A, C,and D, the notch produces a stress concentration that increasesthe probability of a brittle, rather than a ductile, fracture. InTest Method E, the impact resistance is obtained breakage byflexural shock as indicated by the energy extracted from byreversing the notched specimen 180° in the clamping vise. Theresults of all test methods are reported in terms of energyabsorbed per unit of specimen width or per unit of cross-sectional area under the notch. (See Note 4.)

NOTE 1—The machines with their pendulum-type hammers have been“standardized” in that they must comply with certain requirements,including a fixed height of hammer fall that results in a substantially fixedvelocity of the hammer at the moment of impact. However, hammers ofdifferent initial energies (produced by varying their effective weights) arerecommended for use with specimens of different impact resistance.Moreover, manufacturers of the equipment are permitted to use differentlengths and constructions of pendulums with possible differences inpendulum rigidities resulting. (See Section 5.) Be aware that otherdifferences in machine design may exist. The specimens are “standard-ized” in that they are required to have one fixed length, one fixed depth,and one particular design of milled notch. The width of the specimens ispermitted to vary between limits.

NOTE 2—Results generated using pendulums that utilize a load cell torecord the impact force and thus impact energy, may not be equivalent toresults that are generated using manually or digitally encoded testers thatmeasure the energy remaining in the pendulum after impact.

NOTE 3—The notch in the Izod specimen serves to concentrate thestress, minimize plastic deformation, and direct the fracture to the part ofthe specimen behind the notch. Scatter in energy-to-break is thus reduced.However, because of differences in the elastic and viscoelastic propertiesof plastics, response to a given notch varies among materials. A measure

of a plastic’s “notch sensitivity” may be obtained with Test Method D bycomparing the energies to break specimens having different radii at thebase of the notch.

NOTE 4—Caution must be exercised in interpreting the results of thesestandard test methods. The following testing parameters may affect testresults significantly:

Method of fabrication, including but not limited to processingtechnology, molding conditions, mold design, and thermaltreatments;

Method of notching;Speed of notching tool;Design of notching apparatus;Quality of the notch;Time between notching and test;Test specimen thickness,Test specimen width under notch, andEnvironmental conditioning.

1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.


NOTE 5—These test methods resemble ISO 180:1993 in regard to titleonly. The contents are significantly different.


2.1 ASTM Standards:D 618 Practice for Conditioning Plastics for Testing2


D 3641 Practice for Injection Molding Test Specimens ofThermoplastics Molding Extrusion Materials3


D 4066 Specification for Nylon Injection and ExtrusionMaterials3

1 These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.10 on MechanicalProperties.

Current edition approved Nov. 10, 2000. Published January 2001. Originallypublished as D 256 – 26T. Last previous edition D 256 – 97.

2 Annual Book of ASTM Standards, Vol 08.01.3 Annual Book of ASTM Standards, Vol 08.02.

1



D 4812 Test Methods for Unnoticed Cantilever Beam Im-pact Strength of Plastics4

E 691 Practice for Conducting an Interlaboratory Test Pro-gram to Determine the Precision of Test Methods5

2.2 ISO Standard:ISO 180:1993 Plastics—Determination of Izod Impact

Strength of Rigid Materials6

3. Terminology

3.1 Definitions— For definitions related to plastics seeTerminology D 883.

3.2 Definitions of Terms Specific to This Standard:3.2.1 cantilever—a projecting beam clamped at only one

end.3.2.2 notch sensitivity—a measure of the variation of impact

energy as a function of notch radius.

4. Types of Tests

4.1 Four similar methods are presented in these test meth-ods. (See Note 6.) All test methods use the same testingmachine and specimen dimensions. There is no known meansfor correlating the results from the different test methods.

NOTE 6—Test Method B for Charpy has been removed and is beingrevised under a new standard.

4.1.1 In Test Method A, the specimen is held as a verticalcantilever beam and is broken by a single swing of thependulum. The line of initial contact is at a fixed distance fromthe specimen clamp and from the centerline of the notch and onthe same face as the notch.

4.1.2 Test Method C is similar to Test Method A, except forthe addition of a procedure for determining the energy ex-pended in tossing a portion of the specimen. The value reportedis called the “estimated net Izod impact resistance.” TestMethod C is preferred over Test Method A for materials thathave an Izod impact resistance of less than 27 J/m (0.5ft·lbf/in.) under notch. (See Appendix X4 for optional units.)The differences between Test Methods A and C becomeunimportant for materials that have an Izod impact resistancehigher than this value.

4.1.3 Test Method D provides a measure of the notchsensitivity of a material. The stress-concentration at the notchincreases with decreasing notch radius.

4.1.3.1 For a given system, greater stress concentrationresults in higher localized rates-of-strain. Since the effect ofstrain-rate on energy-to-break varies among materials, a mea-sure of this effect may be obtained by testing specimens withdifferent notch radii. In the Izod-type test it has been demon-strated that the function, energy-to-break versus notch radius,is reasonably linear from a radius of 0.03 to 2.5 mm (0.001 to0.100 in.), provided that all specimens have the same type ofbreak. (See 5.8 and 22.1.)

4.1.3.2 For the purpose of this test, the slope,b (see 22.1),of the line between radii of 0.25 and 1.0 mm (0.010 and 0.040in.) is used, unless tests with the 1.0-mm radius give “non-break” results. In that case, 0.25 and 0.50-mm (0.010 and0.020-in.) radii may be used. The effect of notch radius on theimpact energy to break a specimen under the conditions of thistest is measured by the valueb. Materials with low values ofb,whether high or low energy-to-break with the standard notch,are relatively insensitive to differences in notch radius; whilethe energy-to-break materials with high values ofb is highlydependent on notch radius. The parameterb cannot be used indesign calculations but may serve as a guide to the designerand in selection of materials.

4.2 Test Method E is similar to Test Method A, except thatthe specimen is reversed in the vise of the machine 180° to theusual striking position, such that the striker of the apparatusimpacts the specimen on the face opposite the notch. (See Fig.1, Fig. 2.) Test Method E is used to give an indication of theunnotched impact resistance of plastics; however, results ob-tained by the reversed notch method may not always agree withthose obtained on a completely unnotched specimen. (See28.1.)7,8


5.1 Before proceeding with these test methods, referenceshould be made to the specification of the material being tested.Any test specimen preparation, conditioning, dimensions, and

4 Annual Book of ASTM Standards, Vol 08.03.5 Annual Book of ASTM Standards, Vol 14.02.6 Available from American National Standards Institute, 11 W. 42nd St., 13th

Floor, New York, NY 10036.

7 Supporting data giving results of the interlaboratory tests are available fromASTM Headquarters. Request RR: D20-1021.

8 Supporting data giving results of the interlaboratory tests are available fromASTM Headquarters. Request RR: D20-1026.

TABLE 1 Precision Data, Test Method A—Reversed Notch Izod

NOTE 1—Values in ft·lbf/in. of width (J/m of width).NOTE 2—See Footnote 10.

Material Average SrA SR

B IrC IR

D Number ofLaboratories

Phenolic 0.57 (30.4) 0.024 (1.3) 0.076 (4.1) 0.06 (3.2) 0.21 (11.2) 19Acetal 1.45 (77.4) 0.075 (4.0) 0.604 (32.3) 0.21 (11.2) 1.70 (90.8) 9Reinforced nylon 1.98 (105.7) 0.083 (4.4) 0.245 (13.1) 0.23 (12.3) 0.69 (36.8) 15Polypropylene 2.66 (142.0) 0.154 (8.2) 0.573 (30.6) 0.43 (23.0) 1.62 (86.5) 24ABS 10.80 (576.7) 0.136 (7.3) 0.585 (31.2) 0.38 (20.3) 1.65 (88.1) 25Polycarbonate 16.40 (875.8) 0.295 (15.8) 1.056 (56.4) 0.83 (44.3) 2.98 (159.1) 25

A Sr = within-laboratory standard deviation of the average.B SR = between-laboratories standard deviation of the average.C Ir = 2.83 Sr.D IR = 2.83 SR.

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testing parameters covered in the materials specification shalltake precedence over those mentioned in these test methods. Ifthere is no material specification, then the default conditionsapply.

5.2 The excess energy pendulum impact test indicates theenergy to break standard test specimens of specified size understipulated parameters of specimen mounting, notching, andpendulum velocity-at-impact.

5.3 The energy lost by the pendulum during the breakage ofthe specimen is the sum of the following:

5.3.1 Energy to initiate fracture of the specimen;5.3.2 Energy to propagate the fracture across the specimen;5.3.3 Energy to throw the free end (or ends) of the broken

specimen (“toss correction”);

5.3.4 Energy to bend the specimen;5.3.5 Energy to produce vibration in the pendulum arm;5.3.6 Energy to produce vibration or horizontal movement

of the machine frame or base;5.3.7 Energy to overcome friction in the pendulum bearing

and in the excess energy indicating mechanism, and to over-come windage (pendulum air drag);

5.3.8 Energy to indent or deform plastically the specimen atthe line of impact; and

5.3.9 Energy to overcome the friction caused by the rubbingof the striker (or other part of the pendulum) over the face ofthe bent specimen.

5.4 For relatively brittle materials, for which fracture propa-gation energy is small in comparison with the fracture initiationenergy, the indicated impact energy absorbed is, for allpractical purposes, the sum of factors 5.3.1 and 5.3.3. The tosscorrection (see 5.3.3) may represent a very large fraction of thetotal energy absorbed when testing relatively dense and brittlematerials. Test Method C shall be used for materials that havean Izod impact resistance of less than 27 J/m (0.5 ft·lbf/in.).(See Appendix X4 for optional units.) The toss correctionobtained in Test Method C is only an approximation of the tosserror, since the rotational and rectilinear velocities may not bethe same during the re-toss of the specimen as for the originaltoss, and because stored stresses in the specimen may havebeen released as kinetic energy during the specimen fracture.

5.5 For tough, ductile, fiber filled, or cloth-laminated mate-rials, the fracture propagation energy (see 5.3.2) may be largecompared to the fracture initiation energy (see 5.3.1). Whentesting these materials, factors (see 5.3.2, 5.3.5, and 5.3.9) canbecome quite significant, even when the specimen is accuratelymachined and positioned and the machine is in good conditionwith adequate capacity. (See Note 7.) Bending (see 5.3.4) andindentation losses (see 5.3.8) may be appreciable when testingsoft materials.

NOTE 7—Although the frame and base of the machine should besufficiently rigid and massive to handle the energies of tough specimenswithout motion or excessive vibration, the design must ensure that thecenter of percussion be at the center of strike. Locating the strikerprecisely at the center of percussion reduces vibration of the pendulumarm when used with brittle specimens. However, some losses due topendulum arm vibration, the amount varying with the design of thependulum, will occur with tough specimens, even when the striker isproperly positioned.

5.6 In a well-designed machine of sufficient rigidity andmass, the losses due to factors 5.3.6 and 5.3.7 should be verysmall. Vibrational losses (see 5.3.6) can be quite large whenwide specimens of tough materials are tested in machines ofinsufficient mass, not securely fastened to a heavy base.

5.7 With some materials, a critical width of specimen maybe found below which specimens will appear ductile, asevidenced by considerable drawing or necking down in theregion behind the notch and by a relatively high-energyabsorption, and above which they will appear brittle asevidenced by little or no drawing down or necking and by arelatively low-energy absorption. Since these methods permit avariation in the width of the specimens, and since the widthdictates, for many materials, whether a brittle, low-energybreak or a ductile, high energy break will occur, it is necessary

FIG. 2 Relationship of Vise, Specimen, and Striking Edge to EachOther for Test Method E

FIG. 1 Relationship of Vise, Specimen, and Striking Edge to EachOther for Izod Test Methods A and C

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that the width be stated in the specification covering thatmaterial and that the width be reported along with the impactresistance. In view of the preceding, one should not makecomparisons between data from specimens having widths thatdiffer by more than a few mils.

5.8 The type of failure for each specimen shall be recordedas one of the four categories listed as follows:C Complete Break—A break where the specimen

separates into two or more pieces.H Hinge Break—An incomplete break, such that one

part of the specimen cannot support itself abovethe horizontal when the other part is held vertically(less than 90° included angle).

P Partial Break—An incomplete break that does notmeet the definition for a hinge break but has frac-tured at least 90 % of the distance between thevertex of the notch and the opposite side.

NB Non-Break—An incomplete break where the frac-ture extends less than 90 % of the distance be-tween the vertex of the notch and the oppositeside.

For tough materials, the pendulum may not have the energynecessary to complete the breaking of the extreme fibers andtoss the broken piece or pieces. Results obtained from “non-break” specimens shall be considered a departure from stan-dard and shall not be reported as a standard result. Impactresistance cannot be directly compared for any two materialsthat experience different types of failure as defined in the testmethod by this code. Averages reported must likewise bederived from specimens contained within a single failurecategory. This letter code shall suffix the reported impactidentifying the types of failure associated with the reportedvalue. If more than one type of failure is observed for a samplematerial, then the report will indicate the average impactresistance for each type of failure, followed by the percent ofthe specimens failing in that manner and suffixed by the lettercode.

5.9 The value of the impact methods lies mainly in the areasof quality control and materials specification. If two groups ofspecimens of supposedly the same material show significantlydifferent energy absorptions, types of breaks, critical widths, orcritical temperatures, it may be assumed that they were madeof different materials or were exposed to different processing orconditioning environments. The fact that a material showstwice the energy absorption of another under these conditionsof test does not indicate that this same relationship will existunder another set of test conditions. The order of toughnessmay even be reversed under different testing conditions.

NOTE 8—A documented discrepancy exists between manual and digitalimpact testers, primarily with thermoset materials, including phenolics,having an impact value of less than 54 J/m (1 ft-lb/in.). Comparing dataon the same material, tested on both manual and digital impact testers,may show the data from the digital tester to be significantly lower thandata from a manual tester. In such cases a correlation study may benecessary to properly define the true relationship between the instruments.

TEST METHOD A—CANTILEVER BEAM TEST

6. Apparatus

6.1 The machine shall consist of a massive base on which ismounted a vise for holding the specimen and to which isconnected, through a rigid frame and bearings, a pendulum-type hammer. (See 6.2.) The machine must also have a

pendulum holding and releasing mechanism and a pointer anddial mechanism for indicating the excess energy remaining inthe pendulum after breaking the specimen. Optionally, anelectronic digital display or computer can be used in place ofthe dial and pointer to measure the energy loss and indicate thebreaking energy of the specimen.

6.2 A jig for positioning the specimen in the vise and graphsor tables to aid in the calculation of the correction for frictionand windage also should be included. One type of machine isshown in Fig. 3. One design of specimen-positioning jig isillustrated in Fig. 4. Detailed requirements are given insubsequent paragraphs. General test methods for checking andcalibrating the machine are given in Appendix X1. Additionalinstructions for adjusting a particular machine should besupplied by the manufacturer.

6.3 The pendulum shall consist of a single or multi-membered arm with a bearing on one end and a head,containing the striker, on the other. The arm must be suffi-ciently rigid to maintain the proper clearances and geometricrelationships between the machine parts and the specimen andto minimize vibrational energy losses that are always includedin the measured impact resistance. Both simple and compoundpendulum designs may comply with this test method.

6.4 The striker of the pendulum shall be hardened steel andshall be a cylindrical surface having a radius of curvature of0.80 6 0.20 mm (0.0316 0.008 in.) with its axis horizontaland perpendicular to the plane of swing of the pendulum. Theline of contact of the striker shall be located at the center ofpercussion of the pendulum within62.54 mm (60.100 in.)(See Note 9.) Those portions of the pendulum adjacent to thecylindrical striking edge shall be recessed or inclined at asuitable angle so that there will be no chance for other than thiscylindrical surface coming in contact with the specimen duringthe break.

FIG. 3 Cantilever Beam (Izod-Type) Impact Machine

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NOTE 9—The distance from the axis of support to the center ofpercussion may be determined experimentally from the period of smallamplitude oscillations of the pendulum by means of the followingequation:

L 5 ~g/4p 2!p 2

where:L = distance from the axis of support to the center of percussion, m

(or ft),g = local gravitational acceleration (known to an accuracy of one

part in one thousand), m/s2 (or ft/s 2),p = 3.1416 (4p 2 = 39.48), andp = period, s, of a single complete swing (to and fro) determined by

averaging at least 20 consecutive and uninterrupted swings. Theangle of swing shall be less than 5° each side of center.

6.5 The position of the pendulum holding and releasingmechanism shall be such that the vertical height of fall of thestriker shall be 6106 2 mm (24.06 0.1 in.). This will producea velocity of the striker at the moment of impact of approxi-mately 3.5 m (11.4 ft)/s. (See Note 10.) The mechanism shallbe so constructed and operated that it will release the pendulumwithout imparting acceleration or vibration to it.

NOTE 10—

V 5 ~2gh!0.5

where:V = velocity of the striker at the moment of impact (m/s),g = local gravitational acceleration (m/s2), andh = vertical height of fall of the striker (m).

This assumes no windage or friction.

6.6 The effective length of the pendulum shall be between0.33 and 0.40 m (12.8 and 16.0 in.) so that the requiredelevation of the striker may be obtained by raising thependulum to an angle between 60 and 30° above the horizontal.

6.7 The machine shall be provided with a basic pendulumcapable of delivering an energy of 2.76 0.14 J (2.006 0.10

ft·lbf). This pendulum shall be used with all specimens thatextract less than 85 % of this energy. Heavier pendulums shallbe provided for specimens that require more energy to break.These may be separate interchangeable pendulums or one basicpendulum to which extra pairs of equal calibrated weights maybe rigidly attached to opposite sides of the pendulum. It isimperative that the extra weights shall not significantly changethe position of the center of percussion or the free-hanging restpoint of the pendulum (that would consequently take themachine outside of the allowable calibration tolerances). Arange of pendulums having energies from 2.7 to 21.7 J (2 to 16ft·lbf) has been found to be sufficient for use with most plasticspecimens and may be used with most machines. A series ofpendulums such that each has twice the energy of the next willbe found convenient. Each pendulum shall have an energywithin 6 0.5 % of its nominal capacity.

6.8 A vise shall be provided for clamping the specimenrigidly in position so that the long axis of the specimen isvertical and at right angles to the top plane of the vise. (See Fig.1.) This top plane shall bisect the angle of the notch with atolerance of 0.12 mm (0.005 in.). Correct positioning of thespecimen is generally done with a jig furnished with themachine. The top edges of the fixed and moveable jaws shallhave a radius of 0.256 0.12 mm (0.0106 0.005 in.). Forspecimens whose thickness approaches the lower limitingvalue of 3.00 mm (0.118 in.), means shall be provided toprevent the lower half of the specimen from moving during theclamping or testing operations (see Fig. 4 and Note 11.)

NOTE 11—Some plastics are sensitive to clamping pressure; therefore,cooperating laboratories should agree upon some means of standardizingthe clamping force. One method is using a torque wrench on the screw ofthe specimen vise. If the faces of the vise or specimen are not flat andparallel, a greater sensitivity to clamping pressure may be evident. See thecalibration procedure in Appendix X2 for adjustment and correctioninstructions for faulty instruments.

6.9 When the pendulum is free hanging, the striking surfaceshall come within 0.2 % of scale of touching the front face ofa standard specimen. During an actual swing this element shallmake initial contact with the specimen on a line 22.006 0.05mm (0.876 0.002 in.) above the top surface of the vise.

6.10 Means shall be provided for determining energy re-maining in the pendulum after breaking the specimen. Thismay consist of a pointer and dial mechanism which indicate theheight of rise of the pendulum beyond the point of impact interms of energy removed from that specific pendulum. Sincethe indicated remaining energy must be corrected forpendulum-bearing friction, pointer friction, pointer inertia, andpendulum windage, instructions for making these correctionsare included in 10.3 and Annex A1 and Annex A2. Optionally,an electronic digital display or computer can be used in placeof the dial and pointer to measure the energy loss and indicatethe breaking energy of the specimen. If the electronic displaydoes not automatically correct for windage and friction, it shallbe incumbent for the operator to determine the energy lossmanually. (See Note 12.)

NOTE 12—Many digital indicating systems automatically correct forwindage and friction. The equipment manufacturer may be consulted fordetails concerning how this is performed, or if it is necessary to determine

FIG. 4 Jig for Positioning Specimen for Clamping

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the means for manually calculating the energy loss due to windage andfriction.

6.11 The vise, pendulum, and frame shall be sufficientlyrigid to maintain correct alignment of the hammer and speci-men, both at the moment of impact and during the propagationof the fracture, and to minimize energy losses due to vibration.The base shall be sufficiently massive that the impact will notcause it to move. The machine shall be so designed, con-structed, and maintained that energy losses due to pendulum airdrag (windage), friction in the pendulum bearings, and frictionand inertia in the excess energy-indicating mechanism are heldto a minimum.

6.12 A check of the calibration of an impact machine isdifficult to make under dynamic conditions. The basic param-eters are normally checked under static conditions; if themachine passes the static tests, then it is assumed to beaccurate. The calibration procedure in Appendix X2 should beused to establish the accuracy of the equipment. However, forsome machine designs it might be necessary to change therecommended method of obtaining the required calibrationmeasurements. Other methods of performing the requiredchecks may be substituted, provided that they can be shown to

result in an equivalent accuracy. Appendix X1 also describes adynamic test for checking certain features of the machine andspecimen.

7. Test Specimens

7.1 The test specimens shall conform to the dimensions andgeometry of Fig. 5, except as modified in accordance with 7.2,7.3, 7.4, and 7.5. To ensure the correct contour and conditionsof the specified notch, all specimens shall be notched asdirected in Section 8.

7.2 Molded specimens shall have a width between 3.0 and12.7 mm (0.118 and 0.500 in.). Use the specimen width asspecified in the material specification or as agreed uponbetween the supplier and the customer. All specimens havingone dimension less than 12.7 mm (0.500 in.) shall have thenotch cut on the shorter side. Otherwise, all compression-molded specimens shall be notched on the side parallel to thedirection of application of molding pressure. (Due to the draftof the mold, the notched surface and the opposite surface maynot be parallel in molded specimens. Therefore, it is essentialthat the notched surface be machined parallel to its oppositesurface within 0.025 mm (0.001 in.), removing a minimum of

A 10.16 6 0.05 0.400 6 0.002B 32 6 1 1.26 6 0.04C 64 6 2 2.50 6 0.08D 0.25R 6 0.05 0.010R 6 0.002E 12.7 6 0.2 0.500 6 0.008

FIG. 5 Dimensions of Izod-Type Test Specimen

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material in the process, so as to remain within the allowabletolerance for the specimen depth). (See Fig. 5.)

7.2.1 Extreme care must be used in handling specimens lessthan 6.4 mm (0.250 in.) wide. Such specimens must beaccurately positioned and supported to prevent twist or lateralbuckling during the test. Some materials, furthermore, are verysensitive to clamping pressure (see Note 11).

7.2.2 A critical investigation of the mechanics of impacttesting has shown that tests made upon specimens under 6.4mm (0.250 in.) wide absorb more energy due to crushing,bending, and twisting than do wider specimens. Therefore,specimens 6.4 mm (0.250 in.) or over in width are recom-mended. The responsibility for determining the minimumspecimen width shall be the investigator’s, with due referenceto the specification for that material.

7.2.3 Material specification should be consulted for pre-ferred molding conditions. The type of mold and moldingmachine used and the flow behavior in the mold cavity willinfluence the impact resistance obtained. A specimen takenfrom one end of a molded plaque may give different resultsthan a specimen taken from the other end. Cooperatinglaboratories should therefore agree on standard molds con-forming to the material specification. Practice D 3641 can beused as a guide for general molding tolerances, but refer to thematerial specification for specific molding conditions.

7.2.4 The impact resistance of a plastic material may bedifferent if the notch is perpendicular to, rather than parallel to,the direction of molding. The same is true for specimens cutwith or across the grain of an anisotropic sheet or plate.

7.3 For sheet materials, the specimens shall be cut from thesheet in both the lengthwise and crosswise directions unlessotherwise specified. The width of the specimen shall be thethickness of the sheet if the sheet thickness is between 3.0 and12.7 mm (0.118 and 0.500 in.). Sheet material thicker than 12.7mm shall be machined down to 12.7 mm. Specimens with a12.7-mm square cross section may be tested either edgewise orflatwise as cut from the sheet. When specimens are testedflatwise, the notch shall be made on the machined surface if thespecimen is machined on one face only. When the specimen iscut from a thick sheet, notation shall be made of the portion ofthe thickness of the sheet from which the specimen was cut, forexample, center, top, or bottom surface.

7.4 The practice of cementing, bolting, clamping, or other-wise combining specimens of substandard width to form acomposite test specimen is not recommended and should beavoided since test results may be seriously affected by interfaceeffects or effects of solvents and cements on energy absorptionof composite test specimens, or both. However, if Izod test dataon such thin materials are required when no other means ofpreparing specimens are available, and if possible sources oferror are recognized and acceptable, the following technique ofpreparing composites may be utilized.

7.4.1 The test specimen shall be a composite of individualthin specimens totaling 6.4 to 12.7 mm (0.250 to 0.500 in.) inwidth. Individual members of the composite shall be accuratelyaligned with each other and clamped, bolted, or cementedtogether. The composite shall be machined to proper dimen-sions and then notched. In all such cases the use of composite

specimens shall be noted in the report of test results.7.4.2 Care must be taken to select a solvent or adhesive that

will not affect the impact resistance of the material under test.If solvents or solvent-containing adhesives are employed, aconditioning procedure shall be established to ensure completeremoval of the solvent prior to test.

7.5 Each specimen shall be free of twist (see Note 13) andshall have mutually perpendicular pairs of plane parallelsurfaces and free from scratches, pits, and sink marks. Thespecimens shall be checked for compliance with these require-ments by visual observation against straightedges, squares, andflat plates, and by measuring with micrometer calipers. Anyspecimen showing observable or measurable departure fromone or more of these requirements shall be rejected ormachined to the proper size and shape before testing.

NOTE 13—A specimen that has a slight twist to its notched face of 0.05mm (0.002 in.) at the point of contact with the pendulum striking edge willbe likely to have a characteristic fracture surface with considerable greaterfracture area than for a normal break. In this case the energy to break andtoss the broken section may be considerably larger (20 to 30 %) than fora normal break. A tapered specimen may require more energy to bend itin the vise before fracture.

8. Notching Test Specimens

8.1 Notching shall be done on a milling machine, enginelathe, or other suitable machine tool. Both the feed speed andthe cutter speed shall be constant throughout the notchingoperation (see Note 14). Provision for cooling the specimenwith either a liquid or gas coolant is recommended. A single-tooth cutter shall be used for notching the specimen, unlessnotches of an equivalent quality can be produced with amulti-tooth cutter. Single-tooth cutters are preferred because ofthe ease of grinding the cutter to the specimen contour andbecause of the smoother cut on the specimen. The cutting edgeshall be carefully ground and honed to ensure sharpness andfreedom from nicks and burrs. Tools with no rake and a workrelief angle of 15 to 20° have been found satisfactory.

NOTE 14—For some thermoplastics, cutter speeds from 53 to 150m/min (175 to 490 ft/min) at a feed speed of 89 to 160 mm/min (3.5 to 6.3in./min) without a water coolant or the same cutter speeds at a feed speedof from 36 to 160 mm/min (1.4 to 6.3 in./min) with water coolantproduced suitable notches.

8.2 Specimens may be notched separately or in a group.However, in either case an unnotched backup or “dummy bar”shall be placed behind the last specimen in the sample holderto prevent distortion and chipping by the cutter as it exits fromthe last test specimen.

8.3 The profile of the cutting tooth or teeth shall be such asto produce a notch of the contour and depth in the testspecimen as specified in Fig. 5 (see Note 15). The includedangle of the notch shall be 456 1° with a radius of curvatureat the apex of 0.256 0.05 mm (0.0106 0.002 in.). The planebisecting the notch angle shall be perpendicular to the face ofthe test specimen within 2°.

NOTE 15—There is evidence that notches in materials of widely varyingphysical dimensions may differ in contour even when using the samecutter. If the notch in the specimen should take the contour of the cutter,then the contour of the tip of the cutter may be checked instead of thenotch in the specimen for single-tooth cutters. Under the same condition,

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multi-tooth cutters may be checked by measuring the contour of a strip ofsoft metal shim inserted between two specimens for notching.

8.4 The depth of the plastic material remaining in thespecimen under the notch shall be 10.166 0.05 mm (0.40060.002 in.). This dimension shall be measured, with a microme-ter or other suitable measuring device. (See Fig. 6.)

8.5 Cutter speed and feed speed should be chosen appropri-ate for the material being tested since the quality of the notchmay be adversely affected by thermal deformations andstresses induced during the cutting operation if proper condi-

tions are not selected.9 The notching parameters used shall notalter the physical state of the material such as by raising thetemperature of a thermoplastic above its glass transitiontemperature. In general, high cutter speeds, slow feed rates, andlack of coolant induce more thermal damage than a slow cutterspeed, fast feed speed, and the use of a coolant. Too high a feedspeed/cutter speed ratio, however, may cause impacting and

9 Supporting data are available from ASTM Headquarters. Request RR: D20-1066.

NOTE 1—These views not to scale.NOTE 2—Micrometer to be satin-chrome finished with friction thimble.NOTE 3—Special anvil for micrometer caliper 0 to 25.4 mm range (50.8 mm frame) (0 to 1 in. range (2-in. frame)).NOTE 4—Anvil to be oriented with respect to frame as shown.NOTE 5—Anvil and spindle to have hardened surfaces.NOTE 6—Range: 0 to 25.4 mm (0 to 1 in. in thousandths of an inch).NOTE 7—Adjustment must be at zero when spindle and anvil are in contact.

FIG. 6 Early (ca. 1970) Version of a Notch-Depth Micrometer

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cracking of the specimen. The range of cutter speed/feed ratiospossible to produce acceptable notches can be extended by theuse of a suitable coolant. (See Note 16.) In the case of newtypes of plastics, it is necessary to study the effect of variationsin the notching conditions. (See Note 17.)

NOTE 16—Water or compressed gas is a suitable coolant for manyplastics.

NOTE 17—Embedded thermocouples, or another temperature measur-ing device, can be used to determine the temperature rise in the materialnear the apex of the notch during machining. Thermal stresses inducedduring the notching operation can be observed in transparent materials byviewing the specimen at low magnification between crossed polars inmonochromatic light.

8.6 The specimen notch produced by each cutter will beexamined, at a minimum, after every 500 notches. The notch inthe specimen, made of the material to be tested, shall beinspected and verified. One procedure for the inspection andverification of the notch is presented in Appendix X1. Eachtype of material being notched must be inspected and verifiedat that time. If the angle or radius does not fall within thespecified limits for materials of satisfactory machining charac-teristics, then the cutter shall be replaced with a newlysharpened and honed one. (See Note 18.)

NOTE 18—A carbide-tipped or industrial diamond-tipped notchingcutter is recommended for longer service life.

9. Conditioning

9.1 Conditioning—Condition the test specimens at 2362°C (736 3.6°F) and 506 5 % relative humidity for not lessthan 40 h after notching and prior to testing in accordance withProcedure A of Practice D 618, unless it can be documented(between supplier and customer) that a shorter conditioningtime is sufficient for a given material to reach equilibrium ofimpact resistance.

9.1.1 Note that for some hygroscopic materials, such asnylons, the material specifications (for example, SpecificationD 4066) call for testing “dry as-molded specimens.” Suchrequirements take precedence over the above routine precon-ditioning to 50 % relative humidity and require sealing thespecimens in water vapor-impermeable containers as soon asmolded and not removing them until ready for testing.

9.2 Test Conditions—Conduct tests in the standard labora-tory atmosphere of 236 2°C (73 6 3.6°F) and 506 5 %relative humidity, unless otherwise specified in the materialspecification or by customer requirements. In cases of dis-agreement, the tolerances shall be61°C (61.8°F) and6 2 %relative humidity.

10. Procedure

10.1 At least five and preferably ten or more individualdeterminations of impact resistance must be made on eachsample to be tested under the conditions prescribed in Section9. Each group shall consist of specimens with the samenominal width (60.13 mm (60.005 in.)). In the case ofspecimens cut from sheets that are suspected of being aniso-tropic, prepare and test specimens from each principal direc-tion (lengthwise and crosswise to the direction of anisotropy).

10.2 Estimate the breaking energy for the specimen andselect a pendulum of suitable energy. Use the lightest standard

pendulum that is expected to break each specimen in the groupwith a loss of not more than 85 % of its energy (see Note 19).Check the machine with the proper pendulum in place forconformity with the requirements of Section 6 before startingthe tests. (See Appendix X1.)

NOTE 19—Ideally an impact test would be conducted at a constant testvelocity. In a pendulum-type test, the velocity decreases as the fractureprogresses. For specimens that have an impact energy approaching thecapacity of the pendulum there is insufficient energy to complete the breakand toss. By avoiding the higher 15 % scale energy readings, the velocityof the pendulum will not be reduced below 1.3 m/s (4.4 ft/s). On the otherhand, the use of too heavy a pendulum would reduce the sensitivity of thereading.

10.3 If the machine is equipped with a mechanical pointerand dial, perform the following operations before testing thespecimens:

10.3.1 With the excess energy indicating pointer in itsnormal starting position but without a specimen in the vise,release the pendulum from its normal starting position and notethe position the pointer attains after the swing as one reading ofFactorA.

10.3.2 Without resetting the pointer, raise the pendulum andrelease again. The pointer should move up the scale anadditional amount. Repeat (10.3.2) until a swing causes noadditional movement of the pointer and note the final readingas one reading of FactorB (see Note 20).

10.3.3 Repeat the preceding two operations several timesand calculate and record the averageA andB readings.

NOTE 20—FactorB is an indication of the energy lost by the pendulumto friction in the pendulum bearings and to windage. The differenceA – Bis an indication of the energy lost to friction and inertia in the excessenergy indicating mechanism. However, the actual corrections will besmaller than these factors, since in an actual test the energy absorbed bythe specimen prevents the pendulum from making a full swing. Therefore,the indicated breaking energy of the specimen must be included in thecalculation of the machine correction before determining the breakingenergy of the specimen (see 10.7). TheA and B values also provide anindication of the condition of the machine.

10.3.4 If excessive friction is indicated, the machine shall beadjusted before starting a test. If the machine is equipped witha digital energy indicating system, follow the manufacturer’sinstructions to correct for windage and friction. If excessivefriction is indicated, the machine shall be adjusted beforestarting a test.

10.4 Check the specimens for conformity with the require-ments of Sections 7, 8, and 10.1.

10.5 Measure the width and depth to the nearest 0.025 mm(0.001 in.) after notching of each specimen. Measure the widthin the region of the notch. A micrometer or other measuringdevice is necessary for measuring the depth. (See Fig. 6.)

10.6 Position the specimen precisely (see 6.7) so that it isrigidly, but not too tightly (see Note 11), clamped in the vise.Pay special attention to ensure that the “impacted end” of thespecimen as shown and dimensioned in Fig. 5 is the endprojecting above the vise. Release the pendulum and record theexcess energy remaining in the pendulum after breaking thespecimen, together with a description of the appearance of thebroken specimen (see failure categories in 5.8).

10.7 Subtract the windage and friction correction from the

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indicated breaking energy of the specimen, unless determinedautomatically by the indicating system (that is, digital displayor computer). If a mechanical dial and pointer is employed, usethe A and B factors and the appropriate tables or the graphdescribed in Annex A1 and Annex A2 to determine thecorrection. For those digital systems that do not automaticallycompensate for windage and friction, follow the manufactur-er’s procedure for performing this correction.

10.7.1 In other words, either manually or automatically, thewindage and friction correction value is subtracted from theuncorrected, indicated breaking energy to obtain the newbreaking energy. Compare the net value so found with theenergy requirement of the hammer specified in 10.2. If ahammer of improper energy was used, discard the result andmake additional tests on new specimens with the properhammer. (See Annex A1 and Annex A2.)

10.8 Divide the net value found in 10.7 by the measuredwidth of the particular specimen to obtain the impact resistanceunder the notch in J/m (ft·lbf/in.). If the optional units of kJ/m2 (ft·lbf/in.2) are used, divide the net value found in 10.7 by themeasured width and depth under the notch of the particularspecimen to obtain the impact strength. The term, “depth underthe notch,” is graphically represented by Dimension A in Fig.5. Consequently, the cross-sectional area (width times depthunder the notch) will need to be reported. (See Appendix X4.)

10.9 Calculate the average Izod impact resistance of thegroup of specimens. However, only values of specimenshaving the same nominal width and type of break may beaveraged. Values obtained from specimens that did not break inthe manner specified in 5.8 shall not be included in the average.Also calculate the standard deviation of the group of values.

11. Report

11.1 Report the following information:11.1.1 The test method used (Test Method A, C, D, or E),11.1.2 Complete identification of the material tested, includ-

ing type source, manufacturer’s code number, and previoushistory,

11.1.3 A statement of how the specimens were prepared, thetesting conditions used, the number of hours the specimenswere conditioned after notching, and, for sheet materials, thedirection of testing with respect to anisotropy, if any,

11.1.4 The capacity of the pendulum in joules, or footpound-force, or inch pound-force,

11.1.5 The width and depth under the notch of each speci-men tested,

11.1.6 The total number of specimens tested per sample ofmaterial,

11.1.7 The type of failure (see 5.8),11.1.8 The impact resistance must be reported in J/m

(ft·lbf/in.); the optional units of kJ/m2 (ft·lbf/in.2) may also berequired (see 10.8),

11.1.9 The number of those specimens that resulted infailures which conforms to each of the requirement categoriesin 5.8,

11.1.10 The average impact resistance and standard devia-tion (in J/m (ft·lbf/in.)) for those specimens in each failurecategory, except non-break as presented in 5.8. Optional units

(kJ/m2 (ft·lbf/in.2)) may also need to be reported (see AppendixX4), and

11.1.11 The percent of specimens failing in each categorysuffixed by the corresponding letter code from 5.8.

TEST METHOD C—CANTILEVER BEAM TEST FORMATERIALS OF LESS THAN 27 J/m (0.5 ft·lbf/in.)

12. Apparatus

12.1 The apparatus shall be the same as specified in Section6.

13. Test Specimens

13.1 The test specimens shall be the same as specified inSection 7.


14.1 Notching test specimens shall be the same as specifiedin Section 8.

15. Conditioning

15.1 Specimen conditioning and test environment shall bein accordance with Section 9.

16. Procedure

16.1 The procedure shall be the same as in Section 10 withthe addition of a procedure for estimating the energy to toss thebroken specimen part.

16.1.1 Make an estimate of the magnitude of the energy totoss each different type of material and each different specimensize (width). This is done by repositioning the free end of thebroken specimen on the clamped portion and striking it asecond time with the pendulum released in such a way as toimpart to the specimen approximately the same velocity it hadattained during the test. This is done by releasing the pendulumfrom a height corresponding to that to which it rose followingthe breakage of the test specimen. The energy to toss is thenconsidered to be the difference between the reading previouslydescribed and the free swing reading obtained from this height.A reproducible method of starting the pendulum from theproper height must be devised.

17. Report

17.1 Report the following information:17.1.1 Same as 11.1.1,17.1.2 Same as 11.1.2,17.1.3 Same as 11.1.3,17.1.4 Same as 11.1.4,17.1.5 Same as 11.1.5,17.1.6 Same as 11.1.6,17.1.7 The average reversed notch impact resistance, J/m

(ft·lbf/in.) (see 5.8 for failure categories),17.1.8 Same as 11.1.8,17.1.9 Same as 11.1.9,17.1.10 Same as 11.1.10, and17.1.11 Same as 11.1.11.17.1.12 The estimated toss correction, expressed in terms of

joule (J) or foot pound-force (ft·lbf).17.1.13 The difference between the Izod impact energy and

the toss correction energy is the net Izod energy. This value is

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divided by the specimen width (at the base of notch) to obtainthe net Izod impact resistance for the report.

TEST METHOD D—NOTCH RADIUS SENSITIVITYTEST

18. Apparatus


19. Test Specimens

19.1 The test specimens shall be the same as specified inSection 7. All specimens must be of the same nominal width,preferably 6.4-mm (0.25-in.).


20.1 Notching shall be done as specified in Section 8 andFig. 5, except those ten specimens shall be notched with aradius of 0.25 mm (0.010 in.) and ten specimens with a radiusof 1.0 mm (0.040 in.).

21. Conditioning


22. Procedure

22.1 Proceed in accordance with Section 10, testing tenspecimens of each notch radius.

22.2 The average impact resistance of each group shall becalculated, except that within each group the type of breakmust be homogeneously C, H, C and H, or P.

22.3 If the specimens with the 0.25-mm (0.010-in.) radiusnotch do not break, the test is not applicable.

22.4 If any of ten specimens tested with the 1.0-mm(0.040-in.) radius notch fail as in category NB, non-break, thenotch sensitivity procedure cannot be used without obtainingadditional data. A new set of specimens should be preparedfrom the same sample, using a 0.50-mm (0.020-in.) notchradius and the procedure of 22.1 and 22.2 repeated.

23. Calculation

23.1 Calculate the slope of the line connecting the values forimpact resistance for 0.25 and 1.0-mm notch radii (or 0.010and 0.040-in. notch radii) by the equation presented as follows.(If a 0.500-mm (0.020-in.) notch radius is substituted, adjustthe calculation accordingly.)

b 5 ~E2 2 E 1!/~R2 2 R1!

where:E 2 = average impact resistance for the larger notch, J/m of

notch,E1 = average impact resistance for the smaller notch, J/m

of notch,R2 = radius of the larger notch, mm, andR 1 = radius of the smaller notch, mm.

Example:

E1.0 5 330.95 J/m;E0.25 5 138.78 J/m

b 5 ~330.952 138.78 J/m!/~1.002 0.25 mm!

b 5 192.17 J/m 0.75 mm5 256.23 J/mof notch per mm of radius

24. Report

24.1 Report the following information:24.1.1 Same as 11.1.1,24.1.2 Same as 11.1.2,24.1.3 Same as 11.1.3,24.1.4 Same as 11.1.4,24.1.5 Same as 11.1.5,24.1.6 Same as 11.1.6,24.1.7 The average reversed notch impact resistance, in J/m

(ft·lbf/in.) (see 5.8 for failure categories),24.1.8 Same as 11.1.8,24.1.9 Same as 11.1.9,24.1.10 Same as 11.1.10, and24.1.11 Same as 11.1.11.24.1.12 Report the average value ofb with its units, and the

average Izod impact resistance for a 0.25-mm (0.010-in.)notch.

TEST METHOD E—CANTILEVER BEAM REVERSEDNOTCH TEST

25. Apparatus


26. Test Specimens

26.1 The test specimen shall be the same as specified inSection 7.


27.1 Notch the test specimens in accordance with Section 8.

28. Conditioning


29. Procedure

29.1 Proceed in accordance with Section 10, except clampthe specimen so that the striker impacts it on the face oppositethe notch, hence subjecting the notch to compressive ratherthan tensile stresses during impact (see Fig. 2 and Note 21,Note 22, and Note 23).

NOTE 21—The reversed notch test employs a standard 0.25-mm (0.010-in.) notch specimen to provide an indication of unnotched impactresistance. Use of the reversed notch test obviates the need for machiningunnotched specimens to the required 10.26 0.05-mm (0.4006 0.002-in.)depth before testing and provides the same convenience of specimenmounting as the standard notch tests (Test Methods A and C).

NOTE 22—Results obtained by the reversed notch test may not alwaysagree with those obtained on unnotched bars that have been machined tothe 10.2-mm (0.400-in.) depth requirement. For some materials, theeffects arising from the difference in the clamped masses of the twospecimen types during test, and those attributable to a possible differencein toss energies ascribed to the broken ends of the respective specimens,may contribute significantly to a disparity in test results.

NOTE 23—Where materials are suspected of anisotropy, due to moldingor other fabricating influences, notch reversed notch specimens on the faceopposite to that used for the standard Izod test; that is, present the sameface to the impact blow.

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30. Report

30.1 Report the following information:30.1.1 Same as 11.1.1,30.1.2 Same as 11.1.2,30.1.3 Same as 11.1.3,30.1.4 Same as 11.1.4,30.1.5 Same as 11.1.5,30.1.6 Same as 11.1.6,30.1.7 The average reversed notch impact resistance, J/m

(ft·lbf/in.) (see 5.8 for failure categories),30.1.8 Same as 11.1.8,30.1.9 Same as 11.1.9,30.1.10 Same as 11.1.10, and30.1.11 Same as 11.1.11.

31. Precision and Bias

31.1 Table 1 and Table 2 are based on a round robin10 inaccordance with Practice E 691. For each material, all the testbars were prepared at one source, except for notching. Eachparticipating laboratory notched the bars that they tested. Table1 and Table 2 are presented on the basis of a test result beingthe average for five specimens. In the round robin eachlaboratory tested, on average, nine specimens of each material.

31.2 Table 3 is based on a round robin8 involving fivematerials tested by seven laboratories. For each material, all thesamples were prepared at one source, and the individualspecimens were all notched at the same laboratory. Table 3 ispresented on the basis of a test result being the average for fivespecimens. In the round robin, each laboratory tested tenspecimens of each material. (See Note 24.)

NOTE 24—Caution: The following explanations ofIrand IR (see 31.3-31.3.3) are only intended to present a meaningful way of considering theprecision of this test method. The data in Tables 1-3 should not berigorously applied to acceptance or rejection of material, as those data arespecific to the round robin and may not be representative of other lots,conditions, materials, or laboratories. Users of this test method shouldapply the principles outlined in Practice E 691 to generate data specific totheir laboratory and materials, or between specific laboratories. Theprinciples of 31.3-31.3.3 would then be valid for such data.

31.3 Concept of Ir and IR—If Sr andSR have been calculatedfrom a large enough body of data, and for test results that wereaverages from testing five specimens.

31.3.1 Repeatability, Ir (Comparing Two Test Results for theSame Material, Obtained by the Same Operator Using theSame Equipment on the Same Day)—The two test resultsshould be judged not equivalent if they differ by more than theIr value for that material.

31.3.2 Reproducibility, IR (Comparing Two Test Results forthe Same Material, Obtained by Different Operators UsingDifferent Equipment on Different Days)—The two test resultsshould be judged not equivalent if they differ by more than theIR value for that material.

31.3.3 Any judgment in accordance with 31.3.1 and 31.3.2would have an approximate 95 % (0.95) probability of beingcorrect.

31.4 Bias—There is no recognized standards by which toestimate bias of these test methods.

NOTE 25—Numerous changes have occurred since the collection of theoriginal round-robin data in 1973.10 Consequently, a new task group hasbeen formed to evaluate a precision and bias statement for the latestrevision of these test methods.

32. Keywords

32.1 impact resistance; Izod impact; notch sensitivity;notched specimen; reverse notch impact

10 Supporting data are available from ASTM Headquarters. Request RR: D20-1034.

TABLE 2 Precision Data, Test Method C—Reversed Notch Izod



B IrC IR

D Number ofLaboratories

Phenolic 0.45 (24.0) 0.038 (2.0) 0.129 (6.9) 0.10 (5.3) 0.36 (19.2) 15A Sr = within-laboratory standard deviation of the average.B SR = between-laboratories standard deviation of the average.C Ir = 2.83 Sr.D IR = 2.83 SR.

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ANNEXES


A1. INSTRUCTIONS FOR THE CONSTRUCTION OF A WINDAGE AND FRICTION CORRECTION CHART

A1.1 The construction and use of the chart herein describedis based upon the assumption that the friction and windagelosses are proportional to the angle through which these losstorques are applied to the pendulum. Fig. A1.1 shows theassumed energy loss versus the angle of the pendulum positionduring the pendulum swing. The correction chart to be de-scribed is principally the left half of Fig. A1.1. The windageand friction correction charts should be available from com-mercial testing machine manufacturers. The energy lossesdesignated asA andB are described in 10.3.

A1.2 Start the construction of the correction chart (see Fig.A1.2) by laying off to some convenient linear scale on theabscissa of a graph the angle of pendulum position for theportion of the swing beyond the free hanging position. Forconvenience, place the free hanging reference point on theright end of the abscissa with the angular displacementincreasing linearly to the left. The abscissa is referred to asScale C. Although angular displacement is the quantity to berepresented linearly on the abscissa, this displacement is moreconveniently expressed in terms of indicated energy read fromthe machine dial. This yields a nonlinear Scale C with indicatedpendulum energy increasing to the right.

A1.3 On the right-hand ordinate lay off a linear Scale B

starting with zero at the bottom and stopping at the maximumexpected pendulum friction and windage value at the top.

A1.4 On the left ordinate construct a linear Scale D rangingfrom zero at the bottom to 1.2 times the maximum ordinatevalue appearing on Scale B, but make the scale twice the scaleused in the construction of Scale B.

A1.5 Adjoining Scale D draw a curve OA that is the focusof points whose coordinates have equal values of energycorrection on Scale D and indicated energy on Scale C. Thiscurve is referred to as Scale A and utilizes the same divisionsand numbering system as the adjoining Scale D.

A1.6 Instructions for Using Chart:

A1.6.1 Locate and mark on Scale A the reading A obtainedfrom the free swing of the pendulum with the pointer prepo-sitioned in the free hanging or maximum indicated energyposition on the dial.

TABLE 3 Precision Data, Test Method E—Reversed Notch Izod



B IrC IR

D

Acrylic sheet, unmodified 3.02 (161.3) 0.243 (13.0) 0.525 (28.0) 0.68 (36.3) 0.71 (37.9)Premix molding compounds laminate 6.11 (326.3) 0.767 (41.0) 0.786 (42.0) 2.17 (115.9) 2.22 (118.5)acrylic, injection molded 10.33 (551.6) 0.878 (46.9) 1.276 (68.1) 2.49 (133.0) 3.61 (192.8)compound (SMC) laminate 11.00 (587.4) 0.719 (38.4) 0.785 (41.9) 2.03 (108.4) 2.22 (118.5)Preformed mat laminate 19.43 (1037.6) 0.960 (51.3) 1.618 (86.4) 2.72 (145.2) 4.58 (244.6)

A Sr = within-laboratory standard deviation of the average.B SR = between-laboratories standard deviation of the average.C Ir = 2.83 Sr.D IR = 2.83 SR.

FIG. A1.1 Method of Construction of a Windage and FrictionCorrection Chart

FIG. A1.2 Sample Windage and Friction Correction Chart

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A1.6.2 Locate and mark on Scale B the reading B obtainedafter several free swings with the pointer pushed up close to thezero indicated energy position of the dial by the pendulum inaccordance with instructions in 10.3.

A1.6.3 Connect the two points thus obtained by a straightline.

A1.6.4 From the indicated impact energy on Scale C projectup to the constructed line and across to the left to obtain thecorrection for windage and friction from Scale D.

A1.6.5 Subtract this correction from the indicated impactreading to obtain the energy delivered to the specimen.

A2. PROCEDURE FOR THE CALCULATION OF WINDAGE AND FRICTION CORRECTION

A2.1 The procedure for the calculation of the windage andfriction correction in this annex is based on the equationsdeveloped by derivation in Appendix X3. This procedure canbe used as a substitute for the graphical procedure described inAnnex A1 and is applicable to small electronic calculator andcomputer analysis.

A2.2 CalculateL, the distance from the axis of support tothe center of percussion as indicated in 6.3. (It is assumed herethat the center of percussion is approximately the same as thecenter of gravity.)

A2.3 Measure the maximum height,hM, of the center ofpercussion (center of gravity) of the pendulum at the start ofthe test as indicated in X2.16.

A2.4 Measure and record the energy correction,EA, forwindage of the pendulum plus friction in the dial, as deter-mined with the first swing of the pendulum with no specimenin the testing device. This correction must be read on theenergy scale,EM, appropriate for the pendulum used.

A2.5 Without resetting the position of the indicator ob-tained in A2.4, measure the energy correction,EB , forpendulum windage after two additional releases of the pendu-lum with no specimen in the testing device.

A2.6 Calculateb max as follows:

bmax 5 cos21 $1 2 @~hM/L!~1 2 EA/EM!#%

where:EA = energy correction for windage of pendulum plus

friction in dial, J (ft·lbf),EM = full-scale reading for pendulum used, J (ft·lbf),L = distance from fulcrum to center of gravity of

pendulum, m (ft),

hM = maximum height of center of gravity of pendulumat start of test, m (ft), and

b max = maximum angle pendulum will travel with oneswing of the pendulum.

A2.7 Measure specimen breaking energy,Es, J (ft·lbf).

A2.8 Calculateb for specimen measurementEs as:

b 5 cos21 $1 2 @~hM/L!~1 2 Es/EM!#%

where:b = angle pendulum travels for a given specimen, andEs = dial reading breaking energy for a specimen, J (ft·lbf).

A2.9 Calculate total correction energy,ETC, as:

ETC 5 ~EA 2 ~EB/ 2!!~b/bmax! 1 ~EB/2!

where:ETC = total correction energy for the breaking energy,Es,

of a specimen, J (ft·lbf), andEB = energy correction for windage of the pendulum, J

(ft·lbf).

A2.10 Calculate the impact resistance using the followingformula:

Is 5 ~Es 2 ETC!/t

where:Is = impact resistance of specimen, J/m (ft·lbf/in.) of width,

andt = width of specimen or width of notch, m (in.).

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APPENDIXES

(Nonmandatory Information)

X1. PROCEDURE FOR THE INSPECTION AND VERIFICATION OF NOTCH

X1.1 The purpose of this procedure is to describe themicroscopic method to be used for determining the radius andangle of the notch. These measurements could also be madeusing a comparator if available.

NOTE X1.1—The notch shall have a radius of 0.256 0.05 mm (0.0106 0.002 in.) and an angle of 456 1°.

X1.2 Apparatus:

X1.2.1 Optical Device with minimum magnification of603, Filar glass scale and camera attachment.

X1.2.2 Transparent Template, (will be developed in thisprocedure).

X1.2.3 Ruler.X1.2.4 Compass.X1.2.5 Plastic 45°–45°–90° Drafting Set Squares (Tri-

angles).

X1.3 A transparent template must be developed for eachmagnification and for each microscope used. It is preferablethat each laboratory standardize on one microscope and onemagnification. It is not necessary for each laboratory to use thesame magnification because each microscope and cameracombination has somewhat different blowup ratios.

X1.3.1 Set the magnification of the optical device at asuitable magnification with a minimum magnification of 603.

X1.3.2 Place the Filar glass slide on the microscope plat-form. Focus the microscope so the most distinct image of theFilar scale is visible.

X1.3.3 Take a photograph of the Filar scale (see Fig. X1.1).X1.3.4 Create a template similar to that shown in Fig. X1.2.X1.3.4.1 Find the approximate center of the piece of paper.X1.3.4.2 Draw a set of perpendicular coordinates through

the center point.X1.3.4.3 Draw a family of concentric circles that are spaced

according to the dimensions of the Filar scale.

X1.3.4.4 This is accomplished by first setting a mechanicalcompass at a distance of 0.1 mm (0.004 in.) as referenced bythe magnified photograph of the Filar eyepiece. Subsequentcircles shall be spaced 0.02 mm apart (0.001 in.), as rings withthe outer ring being 0.4 mm (0.016 in.) form the center.

X1.3.5 Photocopy the paper with the concentric circles tomake a transparent template of the concentric circles.

X1.3.6 Construct Fig. X1.3 by taking a second piece ofpaper and find it’s approximate center and mark this point.Draw one line through this center point. Label this line zerodegree (0°). Draw a second line perpendicular to the first linethrough this center point. Label this line “90°.” From the centerdraw a line that is 44 degrees relative to the “0°.” Label the line“44°.” Draw another line at 46°. Label the line “46°.”

X1.4 Place a microscope glass slide on the microscopeplatform. Place the notched specimen on top of the slide. Focusthe microscope. Move the specimen around using the platformadjusting knobs until the specimen’s notch is centered and nearthe bottom of the viewing area. Take a picture of the notch.

X1.4.1 Determination of Notching Radius(see Fig. X1.4):X1.4.1.1 Place the picture on a sheet of paper. Position the

picture so that bottom of the notch in the picture facesdownwards and is about 64 mm (2.5 in.) from the bottom of the

NOTE 1—100X reference.NOTE 2—0.1 mm major scale; 0.01 mm minor scale.

FIG. X1.1 Filar Scale

NOTE 1—Magnification = 100X.FIG. X1.2 Example of Transparent Template for Determining

Radius of Notch

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paper. Tape the picture down to the paper.X1.4.1.2 Draw two lines along the sides of the notch

projecting down to a point where they intersect below NotchPoint I (see Fig. X1.4).

X1.4.1.3 Open the compass to about 51 mm (2 in.). UsingPoint I as a reference, draw two arcs intersecting both sides ofthe notch (see Fig. X1.4). These intersections are called 1a and1b.

X1.4.1.4 Close the compass to about 38 mm (1.5 in.). UsingPoint 1a as the reference point draw an arc (2a) above thenotch, draw a second arc (2b) that intersects with arc 2a atPoint J. Draw a line betweenI and J. This establishes thecenterline of the notch (see Fig. X1.4).

X1.4.1.5 Place the transparent template on top of the pictureand align the center of the concentric circles with the drawncenterline of the notch (see Fig. X1.4).

X1.4.1.6 Slide the template down the centerline of the notchuntil one concentric circle touches both sides of the notch.Record the radius of the notch and compare it against theASTM limits of 0.2 to 0.3 mm (0.008 to 0.012 in.).

X1.4.1.7 Examine the notch to ensure that there are no flatspots along the measured radius.

X1.4.2 Determination of Notch Angle:

X1.4.2.1 Place transparent template for determining notchangle (see Fig. X1.3) on top of the photograph attached to thesheet of paper. Rotate the picture so that the notch tip is pointedtowards you. Position the center point of the template on top ofPoint I established in 0° axis of the template with the right sidestraight portion of the notch. Check the left side straightportion of the notch to ensure that this portion falls between the44 and 46° degree lines. If not, replace the blade.

X1.5 A picture of a notch shall be taken at least every 500notches or if a control sample gives a value outside itsthree-sigma limits for that test.

X1.6 If the notch in the control specimen is not within therequirements, a picture of the notching blade should be takenand analyzed by the same procedure used for the specimennotch. If the notching blade does not meet ASTM requirementsor shows damage, it should be replaced with a new blade whichhas been checked for proper dimensions.

X1.7 It is possible that the notching cutter may have thecorrect dimensions but does not cut the correct notch in thespecimen. If that occurs it will be necessary to evaluate otherconditions (cutter and feed speeds) to obtain the correct notchdimension for that material.

FIG. X1.3 Example of Transparent Template for DeterminingAngle of Notch FIG. X1.4 Determination of Notching Radius

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X2. CALIBRATION OF PENDULUM-TYPE HAMMER IMPACT MACHINES FOR USE WITH PLASTICSPECIMENS

X2.1 This calibration procedure applies specifically to theIzod impact machine. However, much of this procedure can beapplied to the Charpy impact machine as well.

X2.2 Locate the impact machine on a sturdy base. It shallnot “walk” on the base and the base shall not vibrate appre-ciably. Loss of energy from vibrations will give high readings.It is recommended that the impact tester be bolted to a basehaving a mass of at least 23 kg if it is used at capacities higherthan 2.7 J (2 ft·lbf).

X2.3 Check the level of the machine in both directions inthe plane of the base with spirit levels mounted in the base, bya machinist’s level if a satisfactory reference surface isavailable, or with a plumb bob. The machine should be madelevel to within tan−1 0.001 in the plane of swing and to withintan −1 0.002 in the plane perpendicular to the swing.

X2.4 With a straightedge and a feeler gage or a depth gage,check the height of the movable vise jaw relative to the fixedvise jaw. It must match the height of the fixed vise jaw within0.08 mm (0.003 in.).

X2.5 Contact the machine manufacturer for a procedure toensure the striker radius is in tolerance (0.806 0.20 mm) (see6.3).

X2.6 Check the transverse location of the center of thependulum striking edge that shall be within 0.40 mm (0.016in.) of the center of the vise. Readjust the shaft bearings orrelocate the vise, or straighten the pendulum shaft as necessaryto attain the proper relationship between the two centers.

X2.7 Check the pendulum arm for straightness within 1.2mm (0.05 in.) with a straightedge or by sighting down theshaft. Allowing the pendulum to slam against the catchsometimes bends the arm especially when high-capacityweights are on the pendulum.

X2.8 Insert vertically and center with a locating jig andclamp in the vise a notched machined metal bar 12.7-mm(0.500-in.) square, having opposite sides parallel within 0.025mm (0.001 in.) and a length of 60 mm (2.4 in.). Check the barfor vertical alignment within tan−1 0.005 in both directionswith a small machinist’s level. Shim up the vise, if necessary,to correct for errors in the plane of pendulum swing, using careto preserve solid support for the vise. For errors in the planeperpendicular to the plane of pendulum swing, machine theinside face of the clamp-type locating jig for correct alignmentif this type of jig is used. If a blade-type jig is used, use shimsor grind the base of the vise to bring the top surface level.

X2.9 Insert and clamp the bar described in X2.8 in avertical position in the center of the vise so that the notch in thebar is slightly below the top edge of the vise. Place a thin filmof oil on the striking edge of the pendulum with an oiled tissueand let the striking edge rest gently against the bar. The striking

edge should make contact across the entire width of the bar. Ifonly partial contact is made, examine the vise and pendulumfor the cause. If the cause is apparent, make the appropriatecorrection. If no cause is apparent, remove the striker and shimup or grind its back face to realign the striking edge with thesurface of the bar.

X2.10 Check the oil line on the face of the bar forhorizontal setting of striking edge within tan−1 0.002 with amachinist’s square.

X2.11 Without taking the bar of X2.8 from the vise of themachine, scratch a thin line at the top edge of the vise on theface opposite the striking face of the bar. Remove the bar fromthe vise and transfer this line to the striking face, using amachinist’s square. The distance from the striking oil line tothe top edge of the vise should be 226 0.05 mm (0.876 0.002in.). Correct with shims or grinding, as necessary, at the bottomof the vise.

X2.12 When the pendulum is hanging free in its lowestposition, the energy reading must be within 0.2 % of full scale.

X2.13 Insert the bar of X2.8 into the vise and clamp ittightly in a vertical position. When the striking edge is held incontact with the bar, the energy reading must be within 0.2 %of full scale.

X2.14 Swing the pendulum to a horizontal position andsupport it by the striking edge in this position with a verticalbar. Allow the other end of this bar to rest at the center of a loadpan on a balanced scale. Subtract the weight of the bar from thetotal weight to find the effective weight of the pendulum. Theeffective pendulum weight should be within 0.4 % of therequired weight for that pendulum capacity. If weight must beadded or removed, take care to balance the added or removedweight without affecting the center of percussion relative to thestriking edge. It is not advisable to add weight to the oppositeside of the bearing axis from the striking edge to decrease theeffective weight of the pendulum since the distributed mass canlead to large energy losses from vibration of the pendulum.

X2.15 Calculate the effective length of the pendulum arm,or the distance to the center of percussion from the axis ofrotation, by the procedure in Note 9. The effective length mustbe within the tolerance stated in 6.3.

X2.16 Measure the vertical distance of fall of the pendulumstriking edge from its latched height to its lowest point. Thisdistance should be 6106 2.0 mm (24 6 0.1 in.). Thismeasurement may be made by blocking up a level on the topof the vise and measuring the vertical distance from the strikingedge to the bottom of the level (top of vise) and subtracting22.0 mm (0.9 in.). The vertical falling distance may be adjustedby varying the position of the pendulum latch.

X2.17 Notch a standard specimen on one side, parallel tothe molding pressure, at 32 mm (1.25 in.) from one end. The

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depth of the plastic material remaining in the specimen underthe notch shall be 10.166 0.05 mm (0.4006 0.002 in.). Usea jig to position the specimen correctly in the vise. When thespecimen is clamped in place, the center of the notch should bewithin 0.12 mm (0.005 in.) of being in line with the top of thefixed surface of the vise and the specimen should be centeredmidway within 0.40 mm (0.016 in.) between the sides of theclamping faces. The notched face should be the striking face ofthe specimen for the Izod test. Under no circumstances duringthe breaking of the specimen should the top of the specimentouch the pendulum except at the striking edge.

X2.18 If a clamping-type locating jig is used, examine theclamping screw in the locating jig. If the thread has a loose fitthe specimen may not be correctly positioned and may tend tocreep as the screw is tightened. A burred or bent point on thescrew may also have the same effect.

X2.19 If a pointer and dial mechanism is used to indicatethe energy, the pointer friction should be adjusted so that thepointer will just maintain its position anywhere on the scale.The striking pin of the pointer should be securely fastened tothe pointer. Friction washers with glazed surfaces should bereplaced with new washers. Friction washers should be oneither side of the pointer collar. A heavy metal washer shouldback the last friction washer installed. Pressure on this metalwasher is produced by a thin-bent, spring washer and locknuts.If the spring washer is placed next to the fiber friction washerthe pointer will tend to vibrate during impact.

X2.20 The free-swing reading of the pendulum (withoutspecimen) from the latched height should be less than 2.5 % ofpendulum capacity on the first swing. If the reading is higherthan this, then the friction in the indicating mechanism isexcessive or the bearings are dirty. To clean the bearings, dipthem in grease solvent and spin-dry in an air jet. Clean thebearings until they spin freely, or replace them. Oil very lightlywith instrument oil before replacing. A reproducible method ofstarting the pendulum from the proper height must be devised.

X2.21 The shaft about which the pendulum rotates shallhave no detectable radial play (less than 0.05 mm (0.002 in.)).An endplay of 0.25 mm (0.010 in.) is permissible when a 9.8-N(2.2-lbf) axial force is applied in alternate directions.

X2.22 The clamping faces of the vise should be parallel in

the horizontal and vertical directions within 0.025 mm (0.001in.). Inserting the machined square metal bar of X2.7 into thevise in a vertical position and clamping until the jaws begin tobind may check parallelism. Any freedom between the metalbar and the clamping surfaces of the jaws of the vise must notexceed the specified tolerance.

X2.23 The top edges of the fixed and moveable jaws of thevise shall have a radius of 0.256 0.12 mm (0.0106 0.005 in.).Depending upon whether Test Method A, C, D, or E is used, astress concentration may be produced as the specimen breaks.Consequently, the top edge of the fixed and moveable jawneeds to be carefully examined.

X2.24 If a brittle unfilled or granular-filled plastic bar suchas a general-purpose wood-flour-filled phenolic material isavailable, notch and break a set of bars in accordance withthese test methods. Examine the surface of the break of eachbar in the vise. If the break is flat and smooth across the topsurface of the vise, the condition of the machine is excellent.Considerable information regarding the condition of an impactmachine can be obtained by examining the broken sections ofspecimens. No weights should be added to the pendulum forthe preceding tests.

X2.25 The machine should not be used to indicate morethan 85 % of the energy capacity of the pendulum. Extraweight added to the pendulum will increase available energy ofthe machine. This weight must be added so as to maintain thecenter of percussion within the tolerance stated in 6.3. Correcteffective weight for any range can be calculated as follows:

W5 Ep/h

where:W = effective pendulum weight, N (lbf) (see X2.13),Ep = potential or available energy of the machine, J (ft·lbf),

andh = vertical distance of fall of the pendulum striking

edge, m (ft) (see X2.16).

Each 4.5 N (1 lbf) of added effective weight increases thecapacity of the machine by 2.7 J (2 ft·lbf).

NOTE X2.1—If the pendulum is designed for use with add-on weight, itis recommended that it be obtained through the equipment manufacturer.

X3. DERIVATION OF PENDULUM IMPACT CORRECTION EQUATIONS

X3.1 From right triangle distances in Fig. X3.1:

L 2 h 5 L cosb (X3.1)

X3.2 But the potential energy gain of pendulumEp is:

Ep 5 hWpg (X3.2)

X3.3 Combining Eq X3.1 and Eq X3.2 gives the following:

L 2 Ep/Wpg 5 L cosb (X3.3)

X3.4 The maximum energy of the pendulum is the potentialenergy at the start of the test,EM, or

EM 5 hMWpg (X3.4)

X3.5 The potential energy gained by the pendulum,Ep, isrelated to the absorption of energy of a specimen,E s, by thefollowing equation:

EM 2 Es 5 Ep (X3.5)

X3.6 Combining Eq X3.3-X3.5 gives the following:

~EM 2 Es!/EM 5 L/hM ~1 2 cosb! (X3.6)

X3.7 Solving Eq X3.6 forb gives the following:

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b 5 cos21$1 2 @~hM/L!~1 2 Es/EM!#% (X3.7)

X3.8 From Fig. X3.2, the total energy correctionETC isgiven as:

ETC 5 mb 1 b (X3.8)

X3.9 But at the zero point of the pendulum potentialenergy:

EB/2 5 m~0! 1 b (X3.9)

or:

b 5 EB/2 (X3.10)

X3.10 The energy correction,EA, on the first swing of thependulum occurs at the maximum pendulum angle,bmax.Substituting in Eq X3.8 gives the following:

EA 5 mbmax1 ~EB/2! (X3.11)

X3.11 Combining Eq X3.8 and Eq X3.11 gives the follow-ing:

ETC 5 ~EA 2 ~EB/2!!~b/bmax! 1 ~EB/2! (X3.12)

X3.12 Nomenclature:

b = intercept of total correction energy straight line,EA = energy correction, including both pendulum wind-

age plus dial friction, J,EB = energy correction for pendulum windage only, J,EM = maximum energy of the pendulum (at the start of

test), J,Ep = potential energy gain of pendulum from the pendu-

lum rest position, J,Es = uncorrected breaking energy of specimen, J,ETC = total energy correction for a given breaking energy,

E s, J,g = acceleration of gravity, m/s2,h = distance center of gravity of pendulum rises verti-

cally from the rest position of the pendulum, m,hM = maximum height of the center of gravity of the

pendulum, m,m = slope of total correction energy straight line,L = distance from fulcrum to center of gravity of pen-

dulum, m,Wp = weight of pendulum, as determined in X2.13, kg,

andb = angle of pendulum position from the pendulum rest

position.

X4. UNIT CONVERSIONS

X4.1 Joules per metre (J/m) cannot be converted directlyinto kJ/m2. Note that the optional units of kJ/m2 (ft·lbf/in.2)may also be required; therefore, the cross-sectional area underthe notch must be reported.

X4.2 The following examples are approximations:

X4.2.1 Example 1:1 ft·lbf/39.37 in. = 1.356 J/m

1 ft·lbf/in. = (39.37)(1.356) J/m1 ft·lbf/in. = 53.4 J/m1 ft·lbf/in. = 0.0534 kJ/m

X4.2.2 Example 2:1 ft·lbf/1550 in.2 = 1.356 J/m2

1 ft·lbf/in.2 = (1550)(1.356) J/m2

1 ft·lbf/in.2 = 2101 J/m2

1 ft·lbf/in.2 = 2.1 kJ/m2

FIG. X3.1 Swing of Pendulum from Its Rest Position

FIG. X3.2 Total Energy Correction for Pendulum Windage andDial Friction as a Function of Pendulum Position

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SUMMARY OF CHANGES

This section identifies the location of selected changes to these test methods. For the convenience of the user,Committee D20 has highlighted those changes that may impact the use of this test method. This section may alsoinclude descriptions of the changes or reasons for the changes, or both.

D 256 – 97:(1) Test Method B (Charpy) has been removed from these testmethods. This test method is being developed as a separatestandard. Research Report D20-1034 will be moved to the newcharpy standard.(2) The designations for Test Methods A, C, D, or E remainunchanged due to potential problems with historical data.(3) These test methods have been extensively revised, edito-

rially and technically, with major emphasis on tolerances andunits.D 256 – 00:(1) Notch depth dimensions in 8.4, Fig. 5, and X2.17 changedto 10.166 0.05 mm.(2) Note 8 added.(3) Deleted former Appendix X4 on Determination of Clamp-ing Load on Izod Specimens.




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Standard Test Method forWater Absorption of Plastics 1


1. Scope

1.1 This test method covers the determination of the relativerate of absorption of water by plastics when immersed. Thistest method is intended to apply to the testing of all types ofplastics, including cast, hot-molded, and cold-molded resinousproducts, and both homogeneous and laminated plastics in rodand tube form and in sheets 0.13 mm (0.005 in.) or greater inthickness.

1.2 The values given in SI units are to be regarded as thestandard. The values stated in parentheses are for informationonly.


NOTE 1—ISO 62 is technically equivalent to this test method.


2.1 ASTM Standards:D 647 Practice for Design of Molds for Test Specimens of

Plastic Molding Materials2

2.2 ISO Standard:ISO 62 Plastics—Determination of Water Absorption3


3.1 This test method for rate of water absorption has twochief functions: first, as a guide to the proportion of waterabsorbed by a material and consequently, in those cases wherethe relationships between moisture and electrical or mechanicalproperties, dimensions, or appearance have been determined,as a guide to the effects of exposure to water or humidconditions on such properties; and second, as a control test onthe uniformity of a product. This second function is particu-larly applicable to sheet, rod, and tube arms when the test ismade on the finished product.

3.2 Comparison of water absorption values of various plas-

tics can be made on the basis of values obtained in accordancewith 7.1 and 7.4.

3.3 Ideal diffusion of liquids4 into polymers is a function ofthe square root of immersion time. Time to saturation isstrongly dependent on specimen thickness. For example, Table1 shows the time to approximate time saturation for variousthickness of nylon-6.

3.4 The moisture content of a plastic is very intimatelyrelated to such properties as electrical insulation resistance,dielectric losses, mechanical strength, appearance, and dimen-sions. The effect upon these properties of change in moisturecontent due to water absorption depends largely on the type ofexposure (by immersion in water or by exposure to highhumidity), shape of the part, and inherent properties of theplastic. With nonhomogeneous materials, such as laminatedforms, the rate of water absorption may be widely differentthrough each edge and surface. Even for otherwise homoge-neous materials, it may be slightly greater through cut edgesthan through molded surfaces. Consequently, attempts tocorrelate water absorption with the surface area must generallybe limited to closely related materials and to similarly shapedspecimens: For materials of widely varying density, relationbetween water-absorption values on a volume as well as aweight basis may need to be considered.

4. Apparatus

4.1 Balance—An analytical balance capable of reading0.0001 g.

4.2 Oven, capable of maintaining uniform temperatures of506 3°C (1226 5.4°F) and of 105 to 110°C (221 to 230°F).

5. Test Specimen

5.1 The test specimen for molded plastics shall be in theform of a disk 50.8 mm (2 in.) in diameter and 3.2 mm (1⁄8 in.)in thickness (see Note 2). Permissible variations in thicknessare 60.18 mm (60.007 in.) for hot-molded and60.30 mm(60.012 in.) for cold-molded or cast materials.

NOTE 2—The disk mold prescribed in the Molds for Disk TestSpecimens Section of Practice D 647 is suitable for molding disk test

1 This test method is under the jurisdiction of ASTM Committee D-20 on Plasticsand is the direct responsibility of Subcommittee D 20.50 on Permanence Properties.

Current edition approved July 10, 1998. Published January 1999. Originallypublished as D 570 – 40 T. Last previous edition D 570 – 95.

2 Discontinued 1994; replaced by D 1896, D 3419, D 3641, D 4703, and D 5227.See 1994Annual Book of ASTM Standards,Vol 08.01.

3 Available from American National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.

4 Additional information regarding diffusion of liquids in polymers can be foundin the following references: (1) Diffusion, Mass Transfer in Fluid Systems,E. L.Cussler, Cambridge University Press, 1985, ISBN 0-521-29846-6, (2) Diffusion inPolymers,J. Crank and G. S. Park, Academic Press, 1968, and (3) “Permeation,Diffusion, and Sorption of Gases and Vapors,” R. M. Felder and G. S. Huvard, inMethods of Experimental Physics,Vol 16C, 1980, Academic Press.

1

Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.

specimens of thermosetting materials but not thermoplastic materials.

5.2 ISO Standard Specimen—The test specimen for homo-geneous plastics shall be 60 by 60 by 1 mm. Tolerance for the60-mm dimension is62 mm and60.05 mm for the 1-mmthickness. This test method and ISO 62 are technically equiva-lent when the test specimen described in 5.2 is used.

5.3 The test specimen for sheets shall be in the form of a bar76.2 mm (3 in.) long by 25.4 mm (1 in.) wide by the thicknessof the material. When comparison of absorption values withmolded plastics is desired, specimens 3.2 mm (1⁄8 in.) thickshould be used. Permissible variations in thickness shall be0.20 mm (60.008 in.) except for asbestos-fabric-base phenoliclaminated materials or other materials which have greaterstandard commercial tolerances.

5.4 The test specimen for rods shall be 25.4 mm (1 in.) longfor rods 25.4 mm in diameter or under and 12.7 mm (1⁄2 in.)long for larger-diameter rods. The diameter of the specimenshall be the diameter of the finished rod.

5.5 The test specimen for tubes less than 76 mm (3 in.) ininside diameter shall be the full section of the tube and 25.4mm (1 in.) long. For tubes 76 mm (3 in.) or more in insidediameter, a rectangular specimen shall be cut 76 mm in lengthin the circumferential direction of the tube and 25.4 mm inwidth lengthwise of the tube.

5.6 The test specimens for sheets, rods, and tubes shall bemachined, sawed, or sheared from the sample so as to havesmooth edges free from cracks. The cut edges shall be madesmooth by finishing with No. 0 or finer sandpaper or emerycloth. Sawing, machining, and sandpapering operations shallbe slow enough so that the material is not heated appreciably.

NOTE 3—If there is any oil on the surface of the specimen whenreceived or as a result of machining operations, wash the specimen witha cloth wet with gasoline to remove oil, wipe with a dry cloth, and allowto stand in air for 2 h to permit evaporation of the gasoline. If gasolineattacks the plastic, use some suitable solvent or detergent that willevaporate within the 2-h period.

5.7 The dimensions listed in the following table for thevarious specimens shall be measured to the nearest 0.025 mm(0.001 in.). Dimensions not listed shall be measured within 0.8mm (61⁄32 in.).

Type ofSpecimen

Dimensions to Be Measured to theNearest 0.025 mm (0.001 in.)

Molded disk thicknessSheet thicknessRod length and diameterTube inside and outside diameter, and wall thickness

6. Conditioning

6.1 Three specimens shall be conditioned as follows:6.1.1 Specimens of materials whose water-absorption value

would be appreciably affected by temperatures in the neigh-borhood of 110°C (230°F), shall be dried in an oven for 24 h

at 506 3°C (1226 5.4°F), cooled in a desiccator, and imme-diately weighed to the nearest 0.001 g.

NOTE 4—If a static charge interferes with the weighing, lightly rub thesurface of the specimens with a grounded conductor.

6.1.2 Specimens of materials, such as phenolic laminatedplastics and other products whose water-absorption value hasbeen shown not to be appreciably affected by temperatures upto 110°C (230°F), shall be dried in an oven for 1 h at 105 to110°C (221 to 230°F).

6.1.3 When data for comparison with absorption values forother plastics are desired, the specimens shall be dried in anoven for 24 h at 506 3°C (1226 5.4°F), cooled in a desic-cator, and immediately weighed to the nearest 0.001 g.

7. Procedure

7.1 Twenty-Four Hour Immersion—The conditioned speci-mens shall be placed in a container of distilled water main-tained at a temperature of 236 1°C (73.46 1.8°F), and shallrest on edge and be entirely immersed. At the end of 24, +1⁄2,−0 h, the specimens shall be removed from the water one at atime, all surface water wiped off with a dry cloth, and weighedto the nearest 0.001 g immediately. If the specimen is1⁄16 in. orless in thickness, it shall be put in a weighing bottle immedi-ately after wiping and weighed in the bottle.

7.2 Two-Hour Immersion—For all thicknesses of materialshaving a relatively high rate of absorption, and for thinspecimens of other materials which may show a significantweight increase in 2 h, the specimens shall be tested asdescribed in 7.1 except that the time of immersion shall bereduced to 1206 4 min.

7.3 Repeated Immersion—A specimen may be weighed tothe nearest 0.001 g after 2-h immersion, replaced in the water,and weighed again after 24 h.

NOTE 5—In using this test method the amount of water absorbed in 24h may be less than it would have been had the immersion not beeninterrupted.

7.4 Long-Term Immersion—To determine the total waterabsorbed when substantially saturated, the conditioned speci-mens shall be tested as described in 7.1 except that at the endof 24 h they shall be removed from the water, wiped free ofsurface moisture with a dry cloth, weighed to the nearest 0.001g immediately, and then replaced in the water. The weighingsshall be repeated at the end of the first week and every twoweeks thereafter until the increase in weight per two-weekperiod, as shown by three consecutive weighings, averages lessthan 1 % of the total increase in weight or 5 mg, whichever isgreater; the specimen shall then be considered substantiallysaturated. The difference between the substantially saturatedweight and the dry weight shall be considered as the waterabsorbed when substantially saturated.

7.5 Two-Hour Boiling Water Immersion—The conditionedspecimens shall be placed in a container of boiling distilledwater, and shall be supported on edge and be entirely im-mersed. At the end of 1206 4 min, the specimens shall beremoved from the water and cooled in distilled water main-tained at room temperature. After 156 1 min, the specimensshall be removed from the water, one at a time, all surfacewater removed with a dry cloth, and the specimens weighed to

TABLE 1 Time to Saturation for Various Thickness of Nylon-6

Thickness, mm Typical Time to 95 % Saturation, h

1 1002 400

3.2 1 00010 10 00025 62 000

D 570

2

the nearest 0.001 g immediately. If the specimen is1⁄16 in. orless in thickness, it shall be weighed in a weighing bottle.

7.6 One-Half-Hour Boiling Water Immersion—For allthicknesses of materials having a relatively high rate ofabsorption and for thin specimens of other materials whichmay show a significant weight increase in1⁄2 h, the specimensshall be tested as described in 7.5, except that the time ofimmersion shall be reduced to 306 1 min.

7.7 Immersion at 50°C—The conditioned specimens shallbe tested as described in 7.5, except that the time andtemperature of immersion shall be 486 1 h and 506 1°C(122.06 1.8°F), respectively, and cooling in water beforeweighing shall be omitted.

7.8 When data for comparison with absorption values forother plastics are desired, the 24-h immersion proceduredescribed in 7.1 and the equilibrium value determined in 7.4shall be used.

8. Reconditioning

8.1 When materials are known or suspected to contain anyappreciable amount of water-soluble ingredients, the speci-mens, after immersion, shall be weighed, and then recondi-tioned for the same time and temperature as used in the originaldrying period. They shall then be cooled in a desiccator andimmediately reweighed. If the reconditioned weight is lowerthan the conditioned weight, the difference shall be consideredas water-soluble matter lost during the immersion test. For suchmaterials, the water-absorption value shall be taken as the sumof the increase in weight on immersion and of the weight of thewater-soluble matter.

9. Calculation and Report

9.1 The report shall include the values for each specimenand the average for the three specimens as follows:

9.1.1 Dimensions of the specimens before test, measured inaccordance with 5.6, and reported to the nearest 0.025 mm(0.001 in.),

9.1.2 Conditioning time and temperature,9.1.3 Immersion procedure used,9.1.4 Time of immersion (long-term immersion procedure

only),9.1.5 Percentage increase in weight during immersion, cal-

culated to the nearest 0.01 % as follows:

Increase in weight, %5wet weight2 conditioned weight

conditioned weight 3100

9.1.6 Percentage of soluble matter lost during immersion, ifdetermined, calculated to the nearest 0.01 % as follows (seeNote 6):

Soluble matter lost, %5conditioned weight2 reconditioned weight

conditioned weight 3 100

NOTE 6—When the weight on reconditioning the specimen after im-mersion in water exceeds the conditioned weight prior to immersion,report “none” under 9.1.6.

9.1.7 For long-term immersion procedure only, prepare agraph of the increase in weight as a function of the square rootof each immersion time. The initial slope of this graph isproportional to the diffusion constant of water in the plastic.The plateau region with little or no change in weight as afunction of the square root of immersion time represents thesaturation water content of the plastic.

NOTE 7—Deviation from the initial slope and plateau model indicatesthat simple diffusion may be a poor model for determining water content.In such cases, additional studies are suggested to determine a better modelfor water absorption.

9.1.8 The percentage of water absorbed, which is the sum ofthe values in 9.1.5 and 9.1.6, and

9.1.9 Any observations as to warping, cracking, or changein appearance of the specimens.


10.1 Precision—An interlaboratory test program was car-ried out using the procedure outlined in 7.1, involving threelaboratories and three materials. Analysis of this data yields thefollowing coefficients of variation (average of three replicates).

WithinLaboratories

BetweenLaboratories

Average absorption above1 % (2 materials)

2.33 % 4.89 %

Average absorption below0.2 % (1 material)

9.01 % 16.63 %

NOTE 8—A round robin is currently under way to more completelydetermine repeatability and reproducibility of this test method.

10.2 Bias—No justifiable statement on the bias of this testmethod can be made, since the true value of the propertycannot be established by an accepted referee method.

11. Keywords

11.1 absorption; immersion; plastics; water

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any suchpatent rights, and the risk of infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsibletechnical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make yourviews known to the ASTM Committee on Standards, at the address shown below.

This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at610-832-9585 (phone), 610-832-9555 (fax), or [email protected] (e-mail); or through the ASTM website (www.astm.org).

5 Supporting data are available from ASTM Headquarters. Request RR: D-20-1064.

D 570

3

LAMPIRAN 2

Tabel.2.1.Data Pengujian Bending Alkali 2 jam

Tebal 2 mm

Jenis No Lebar Tebal Panjang Awal

Luas

komposit Spesimen (mm) (mm) (mm) (mm2)

Volume B/T2-20/1 12.45 2.1 86 1070.7

20% B/T2-20/2 12.75 2.1 86 1096.5

B/T2-20/3 12.5 2.15 86 1075

Volume B/T2-30/1 12.7 2.8 85 1079.5

30% B/T2-30/2 13.3 2.85 84 1117.2

B/T2-30/3 12.95 2.8 86 1113.7

Volume B/T2-40/1 12.55 2.75 85 1066.75

40% B/T2-40/2 13.15 2.75 85 1117.75

B/T2-40/3 12.5 2.7 85 1062.5

Volume B/T2-50/1 13.2 3.35 85 1122

50% B/T2-50/2 12.55 3.45 85 1066.75

B/T2-50/3 13.55 3.3 85 1151.75


Luas


Volume B/T1-20/1 12 1.35 66 792

20% B/T1-20/2 13.05 1.35 66 861.3

B/T1-20/3 12.6 1.35 69 869.4

Volume B/T1-30/1 11.95 1.55 68 812.6

30% B/T1-30/2 12.95 1.8 69 893.55

B/T1-30/3 12.75 1.7 68 867

Volume B/T1-40/1 12.7 2.3 67 850.9

40% B/T1-40/2 12.95 2.25 67 867.65

B/T1-40/3 13.3 2.3 68 904.4

Volume B/T1-50/1 13.65 1.9 68 928.2

50% B/T1-50/2 13.05 1.95 68 887.4

B/T1-50/3 12.9 1.9 67 864.3

Tebal 3 mm


Luas


Volume B/T3-20/1 14.05 3.15 101 1419.05

20% B/T3-20/2 15.05 3.2 101 1520.05

B/T3-20/3 12.15 3.15 102 1239.3

Volume B/T3-30/1 12.65 4.45 100 1265

30% B/T3-30/2 13.3 4.3 100 1330

B/T3-30/3 11.7 4.2 100 1170

Volume B/T3-40/1 12.55 3.55 101 1267.55

40% B/T3-40/2 13.5 3.7 100 1350

B/T3-40/3 14.3 3.7 100 1430

Volume B/T3-50/1 13.15 4.5 100 1315

50% B/T3-50/2 13.25 4.2 100 1325

B/T3-50/3 13.15 4.6 100 1315

Tebal 4 mm


Luas


Volume B/T4-20/1 13.9 4.4 115 1598.5

20% B/T4-20/2 12.95 4.25 114 1476.3

B/T4-20/3 13.75 4.2 114 1567.5

Volume B/T4-30/1 12.7 4.7 114 1447.8

30% B/T4-30/2 13.3 4.6 114 1516.2

B/T4-30/3 12.65 4.7 115 1454.75

Volume B/T4-40/1 13.25 5.35 115 1523.75

40% B/T4-40/2 14.5 5.45 114 1653

B/T4-40/3 13.15 5.55 115 1512.25

Volume B/T4-50/1 13.3 5.15 115 1529.5

50% B/T4-50/2 12.6 5.25 115 1449

B/T4-50/3 12.25 5.05 115 1408.75

Tebal 5 mm


Luas


Volume B/T5-20/1 14 5.4 130 1820

20% B/T5-20/2 13 5.45 130 1690

B/T5-20/3 14.85 5.55 130 1930.5

Volume B/T5-30/1 12.9 5.25 130 1677

30% B/T5-30/2 12.85 5.4 130 1670.5

B/T5-30/3 12.5 5.25 130 1625

Volume B/T5-40/1 12.45 6.05 130 1618.5

40% B/T5-40/2 13.75 5.6 129 1773.75

B/T5-40/3 12.8 5.75 130 1664

Volume B/T5-50/1 13 7.05 130 1690

50% B/T5-50/2 12.4 7 130 1612

B/T5-50/3 13.15 6.8 131 1722.65

Alkali 4 jam

Tebal 1 mm

Jenis No Lebar Tebal Panjang

Awal

Luas


Volume B/T1-20/1 12 1.35 66 792

20% B/T1-20/2 13.05 1.35 66 861.3

B/T1-20/3 12.6 1.35 69 869.4

Volume B/T1-30/1 11.95 1.55 68 812.6

30% B/T1-30/2 12.95 1.8 69 893.55

B/T1-30/3 12.75 1.7 68 867

Volume B/T1-40/1 12.7 2.3 67 850.9

40% B/T1-40/2 12.95 2.25 67 867.65

B/T1-40/3 13.3 2.3 68 904.4

Volume B/T1-50/1 13.65 1.9 68 928.2

50% B/T1-50/2 13.05 1.95 68 887.4

B/T1-50/3 12.9 1.9 67 864.3

Tebal 2 mm


Luas


Volume B/T2-20/1 12.45 2.1 86 1070.7

20% B/T2-20/2 12.75 2.1 86 1096.5

B/T2-20/3 12.5 2.15 86 1075

Volume B/T2-30/1 12.7 2.8 85 1079.5

30% B/T2-30/2 13.3 2.85 84 1117.2

B/T2-30/3 12.95 2.8 86 1113.7

Volume B/T2-40/1 12.55 2.75 85 1066.75

40% B/T2-40/2 13.15 2.75 85 1117.75

B/T2-40/3 12.5 2.7 85 1062.5

Volume B/T2-50/1 13.2 3.35 85 1122

50% B/T2-50/2 12.55 3.45 85 1066.75

B/T2-50/3 13.55 3.3 85 1151.75

Tebal 3 mm


Luas


Volume B/T3-20/1 14.05 3.15 101 1419.05

20% B/T3-20/2 15.05 3.2 101 1520.05

B/T3-20/3 12.15 3.15 102 1239.3

Volume B/T3-30/1 12.65 4.45 100 1265

30% B/T3-30/2 13.3 4.3 100 1330

B/T3-30/3 11.7 4.2 100 1170

Volume B/T3-40/1 12.55 3.55 101 1267.55

40% B/T3-40/2 13.5 3.7 100 1350

B/T3-40/3 14.3 3.7 100 1430

Volume B/T3-50/1 13.15 4.5 100 1315

50% B/T3-50/2 13.25 4.2 100 1325

B/T3-50/3 13.15 4.6 100 1315

Tebal 4 mm


Luas


Volume B/T4-20/1 13.9 4.4 115 1598.5

20% B/T4-20/2 12.95 4.25 114 1476.3

B/T4-20/3 13.75 4.2 114 1567.5

Volume B/T4-30/1 13.3 5.15 115 1529.5

30% B/T4-30/2 12.6 5.25 115 1449

B/T4-30/3 12.25 5.05 115 1408.75

Volume B/T4-40/1 13.25 5.35 115 1523.75

40% B/T4-40/2 14.5 5.45 114 1653

B/T4-40/3 13.15 5.55 115 1512.25

Volume B/T4-50/1 12.7 4.7 114 1447.8

50% B/T4-50/2 13.3 4.6 114 1516.2

B/T4-50/3 12.65 4.7 115 1454.75

Tebal 5 mm


Luas


Volume B/T5-20/1 14 5.4 130 1820

20% B/T5-20/2 13 5.45 130 1690

B/T5-20/3 14.85 5.55 130 1930.5

Volume B/T5-30/1 12.9 5.25 130 1677

30% B/T5-30/2 12.85 5.4 130 1670.5

B/T5-30/3 12.5 5.25 130 1625

Volume B/T5-40/1 13 7.05 130 1690

40% B/T5-40/2 12.4 7 130 1612

B/T5-40/3 13.15 6.8 131 1722.65

Volume B/T5-50/1 12.45 6.05 130 1618.5

50% B/T5-50/2 13.75 5.6 129 1773.75

B/T5-50/3 12.8 5.75 130 1664

Alkali 6 jam

Tebal 1 mm


Luas


Volume B/T1-20/1 12 1.35 66 792

20% B/T1-20/2 13.05 1.35 66 861.3

B/T1-20/3 12.6 1.35 69 869.4

Volume B/T1-30/1 11.95 1.55 68 812.6

30% B/T1-30/2 12.95 1.8 69 893.55

B/T1-30/3 12.75 1.7 68 867

Volume B/T1-40/1 12.7 2.3 67 850.9

40% B/T1-40/2 12.95 2.25 67 867.65

B/T1-40/3 13.3 2.3 68 904.4

Volume B/T1-50/1 13.65 1.9 68 928.2

50% B/T1-50/2 13.05 1.95 68 887.4

B/T1-50/3 12.9 1.9 67 864.3

Tebal 2 mm


Luas


Volume B/T2-20/1 12.45 2.1 86 1070.7

20% B/T2-20/2 12.75 2.1 86 1096.5

B/T2-20/3 12.5 2.15 86 1075

Volume B/T2-30/1 12.7 2.8 85 1079.5

30% B/T2-30/2 13.3 2.85 84 1117.2

B/T2-30/3 12.95 2.8 86 1113.7

Volume B/T2-40/1 12.55 2.75 85 1066.75

40% B/T2-40/2 13.15 2.75 85 1117.75

B/T2-40/3 12.5 2.7 85 1062.5

Volume B/T2-50/1 13.2 3.35 85 1122

50% B/T2-50/2 12.55 3.45 85 1066.75

B/T2-50/3 13.55 3.3 85 1151.75

Tebal 3 mm


Luas


Volume B/T3-20/1 14.05 3.15 101 1419.05

20% B/T3-20/2 15.05 3.2 101 1520.05

B/T3-20/3 12.15 3.15 102 1239.3

Volume B/T3-30/1 12.65 4.45 100 1265

30% B/T3-30/2 13.3 4.3 100 1330

B/T3-30/3 11.7 4.2 100 1170

Volume B/T3-40/1 12.55 3.55 101 1267.55

40% B/T3-40/2 13.5 3.7 100 1350

B/T3-40/3 14.3 3.7 100 1430

Volume B/T3-50/1 13.15 4.5 100 1315

50% B/T3-50/2 13.25 4.2 100 1325

B/T3-50/3 13.15 4.6 100 1315

Tebal 4 mm


Luas


Volume B/T4-20/1 13.9 4.4 115 1598.5

20% B/T4-20/2 12.95 4.25 114 1476.3

B/T4-20/3 13.75 4.2 114 1567.5

Volume B/T4-30/1 12.7 4.7 114 1447.8

30% B/T4-30/2 13.3 4.6 114 1516.2

B/T4-30/3 12.65 4.7 115 1454.75

Volume B/T4-40/1 13.25 5.35 115 1523.75

40% B/T4-40/2 14.5 5.45 114 1653

B/T4-40/3 13.15 5.55 115 1512.25

Volume B/T4-50/1 13.3 5.15 115 1529.5

50% B/T4-50/2 12.6 5.25 115 1449

B/T4-50/3 12.25 5.05 115 1408.75

Tebal 5 mm


Luas


Volume B/T5-20/1 14 5.4 130 1820

20% B/T5-20/2 13 5.45 130 1690

B/T5-20/3 14.85 5.55 130 1930.5

Volume B/T5-30/1 12.9 5.25 130 1677

30% B/T5-30/2 12.85 5.4 130 1670.5

B/T5-30/3 12.5 5.25 130 1625

Volume B/T5-40/1 12.45 6.05 130 1618.5

40% B/T5-40/2 13.75 5.6 129 1773.75

B/T5-40/3 12.8 5.75 130 1664

Volume B/T5-50/1 13 7.05 130 1690

50% B/T5-50/2 12.4 7 130 1612

B/T5-50/3 13.15 6.8 131 1722.65

Alkali 8 jam

Tebal 1 mm


Luas


Volume B/T1-20/1 12 1.35 66 792

20% B/T1-20/2 13.05 1.35 66 861.3

B/T1-20/3 12.6 1.35 69 869.4

Volume B/T1-30/1 11.95 1.55 68 812.6

30% B/T1-30/2 12.95 1.8 69 893.55

B/T1-30/3 12.75 1.7 68 867

Volume B/T1-40/1 12.7 2.3 67 850.9

40% B/T1-40/2 12.95 2.25 67 867.65

B/T1-40/3 13.3 2.3 68 904.4

Volume B/T1-50/1 13.65 1.9 68 928.2

50% B/T1-50/2 13.05 1.95 68 887.4

B/T1-50/3 12.9 1.9 67 864.3

Tebal 2 mm


Luas


Volume B/T2-20/1 12.45 2.1 86 1070.7

20% B/T2-20/2 12.75 2.1 86 1096.5

B/T2-20/3 12.5 2.15 86 1075

Volume B/T2-30/1 12.7 2.8 85 1079.5

30% B/T2-30/2 13.3 2.85 84 1117.2

B/T2-30/3 12.95 2.8 86 1113.7

Volume B/T2-40/1 12.55 2.75 85 1066.75

40% B/T2-40/2 13.15 2.75 85 1117.75

B/T2-40/3 12.5 2.7 85 1062.5

Volume B/T2-50/1 13.2 3.35 85 1122

50% B/T2-50/2 12.55 3.45 85 1066.75

B/T2-50/3 13.55 3.3 85 1151.75

Tebal 3 mm


Luas


Volume B/T3-20/1 14.05 3.15 101 1419.05

20% B/T3-20/2 15.05 3.2 101 1520.05

B/T3-20/3 12.15 3.15 102 1239.3

Volume B/T3-30/1 12.65 4.45 100 1265

30% B/T3-30/2 13.3 4.3 100 1330

B/T3-30/3 11.7 4.2 100 1170

Volume B/T3-40/1 12.55 3.55 101 1267.55

40% B/T3-40/2 13.5 3.7 100 1350

B/T3-40/3 14.3 3.7 100 1430

Volume B/T3-50/1 13.15 4.5 100 1315

50% B/T3-50/2 13.25 4.2 100 1325

B/T3-50/3 13.15 4.6 100 1315

Tebal 4 mm


Luas


Volume B/T4-20/1 13.9 4.4 115 1598.5

20% B/T4-20/2 12.95 4.25 114 1476.3

B/T4-20/3 13.75 4.2 114 1567.5

Volume B/T4-30/1 12.7 4.7 114 1447.8

30% B/T4-30/2 13.3 4.6 114 1516.2

B/T4-30/3 12.65 4.7 115 1454.75

Volume B/T4-40/1 13.25 5.35 115 1523.75

40% B/T4-40/2 14.5 5.45 114 1653

B/T4-40/3 13.15 5.55 115 1512.25

Volume B/T4-50/1 13.3 5.15 115 1529.5

50% B/T4-50/2 12.6 5.25 115 1449

B/T4-50/3 12.25 5.05 115 1408.75

Tebal 5 mm


Luas


Volume B/T5-20/1 14 5.4 130 1820

20% B/T5-20/2 13 5.45 130 1690

B/T5-20/3 14.85 5.55 130 1930.5

Volume B/T5-30/1 12.9 5.25 130 1677

30% B/T5-30/2 12.85 5.4 130 1670.5

B/T5-30/3 12.5 5.25 130 1625

Volume B/T5-40/1 12.45 6.05 130 1618.5

40% B/T5-40/2 13.75 5.6 129 1773.75

B/T5-40/3 12.8 5.75 130 1664

Volume B/T5-50/1 13 7.05 130 1690

50% B/T5-50/2 12.4 7 130 1612

B/T5-50/3 13.15 6.8 131 1722.65

Tabel.2.2.Data Pengujian Tarik Alkali 2 jam

Specimen panjang awal

lebar tebal G (Kgf) ε (mm) luas

20% T1 33 6 1.35 15.11 0.71 198

32 6.5 1.35 17.26 1.25 208

33 7 1.35 10.01 0.61 231

30% T1 31 6 1.55 2.82 0.57 186

32 6 1.8 18.81 0.81 192

33 7 1.7 28.49 1.09 231

40% T1 31 7 1.6 24.74 0.62 217

32 6.5 1.5 18.97 1.12 208

33 6.5 1.5 15.48 0.78 214.5

50% T1 31 6 1.9 45.98 0.83 186

31 7 1.95 18.77 0.73 217

32 7 1.9 28.49 1.09 224

20% T2 32.5 6 2.5 25.65 0.42 195

32 6.5 2 30.55 0.43 208

33 6.4 2.4 28.33 0.39 211.2

30% T2 33.5 6 2.8 42.30 0.43 201

34 5.9 2.5 38.76 0.48 200.6

33 5 2.4 34.10 0.59 165

40% T2 32 6 2.2 74.55 0.60 192

33 6.5 2.4 38.35 0.50 214.5

31.7 7 2.5 45.52 0.42 221.9

50% T2 32.5 6.8 2.3 60.54 0.52 221

32.6 6 2.4 84.13 0.75 195.6

32.5 5.5 2.4 48.84 0.46 178.75

20% T3 33 6.5 3.2 62.75 0.58 214.5

34 6.2 3 43.72 0.32 210.8

33.5 6 3 34.46 0.26 201

30% T3 32 7 3.5 80.07 0.79 224

31.8 6.3 3.5 64.64 0.41 200.34

32.2 7 2.8 55.89 0.30 225.4

40% T3 33.5 7 3 66.77 0.54 234.5

33 6.3 3.4 108.96 0.77 207.9

31.6 5.8 3 114.68 0.08 183.28

50% T3 32 5.5 3.4 127.86 0.64 176

32 6 3.2 125.02 0.86 192

33.6 5.4 3.4 80.02 0.44 181.44

20% T4 33 6 4.4 98.43 0.86 198

34 6.5 3.8 77.49 0.89 221

32.5 6 4.2 94.56 0.78 195

30% T4 31.8 7 3.9 91.53 0.79 222.6

32 6.5 4.2 77.80 0.55 208

32 7 4.5 78.77 0.59 224

40% T4 32.6 6 4 127.72 1.28 195.6

33.2 7 4.6 137.73 1.29 232.4

33.4 6.3 4.8 125.54 1.21 210.42

50% T4 33 6.5 3.5 319.83 1.48 214.5

32 7 4.2 172.29 0.88 224

33.4 7 4.5 309.66 1.49 233.8

20% T5 33 7 4.8 163.42 1.59 231

32.5 7 5 209.19 1.39 227.5

32.6 6.5 5.4 200.10 1.36 211.9

30% T5 33 6.4 6 136.29 1.49 211.2

32 6 5.5 248.40 1.52 192

34 6 4.8 127.59 1.61 204

40% T5 33 6.4 5 158.43 1.43 211.2

32.8 6.5 5.2 251.41 1.49 213.2

33.5 7 5.5 224.02 1.53 234.5

50% T5 33.2 6.8 6 257.15 1.68 225.76

34 6.4 6.2 220.72 1.63 217.6

33.5 6 5.5 345.19 1.25 201

Alkali 4 jam



20% T1 33.5 6.5 1.35 13.70 1.86 217.75

33 6.5 1.35 14.79 0.85 214.5

32 7 1.35 25.21 0.73 224

30% T1 31 6 1.55 11.47 0.73 186

32 6 1.8 15.48 0.78 192

33 7 1.7 20.55 0.85 231

40% T1 31 7 1.6 38.86 0.94 217

32 6.5 1.5 38.82 1.19 208

33 6 1.5 40.79 1.88 198

50% T1 31 6 1.9 27.27 0.57 186

32 7 1.95 30.18 0.78 224

32 6.5 1.9 35.88 0.91 208

20% T2 32 6 2.5 60.34 0.61 192

32 6.5 2 36.52 0.39 208

33 6.4 2.4 13.32 1.40 211.2

30% T2 33 6 2.8 52.00 1.00 198

34 5.9 2.5 20.76 1.21 200.6

33 5 2.4 23.57 1.10 165

40% T2 32 6 2.2 94.98 0.85 192

33 6.5 2.4 65.43 0.59 214.5

32 7 2.5 50.86 0.56 224

50% T2 32.5 6.5 2.3 103.69 0.71 211.25

32 6 2.4 91.18 0.77 192

33 5.5 2.4 89.72 0.57 181.5

20% T3 33 6.5 3.2 43.55 0.33 214.5

32 6.2 3 46.90 0.32 198.4

33 6 3 85.45 0.58 198

30% T3 32 7 3.5 82.52 0.65 224

31.8 6.3 3.5 82.76 0.68 200.34

32.2 7 2.8 85.17 0.58 225.4

40% T3 32 7 3 56.49 0.34 224

33 6.3 3.4 60.89 0.48 207.9

31.6 6 3 79.80 0.86 189.6

50% T3 32 5.5 3.4 155.46 1.04 176

32 6 3.2 144.68 0.81 192

32 5.4 3.4 119.87 0.54 172.8

20% T4 33 6 4.4 66.35 0.35 198

33 6.5 3.8 71.89 0.53 214.5

32.5 6 4.2 112.86 0.61 195

30% T4 31.8 7 3.9 82.94 0.60 222.6

32 6.5 4.2 103.34 0.57 208

32 6.5 4.5 135.73 0.86 208

40% T4 32.6 6 4 120.04 0.68 195.6

33.2 7 4.6 102.73 0.60 232.4

33.4 6.3 4.8 90.39 0.37 210.42

50% T4 33 6.5 3.5 178.03 1.29 214.5

32 7 4.2 157.93 0.65 224

32 7 4.5 135.01 0.60 224

20% T5 33 6.5 4.8 58.43 0.57 214.5

32 7 5 68.37 0.36 224

32 6.5 5.4 70.40 0.34 208

30% T5 33 6.4 6 77.97 0.37 211.2

32 6 5.5 81.95 0.45 192

34 6 4.8 120.52 0.56 204

40% T5 33 6.4 5 111.37 0.47 211.2

32.8 6.5 5.2 102.96 0.71 213.2

32 7 5.5 115.76 0.55 224

50% T5 33.2 6.8 6 233.21 1.14 225.76

33 6.4 6.2 202.29 0.67 211.2

32 6 5.5 180.90 0.66 192

Alkali 6 jam



20% T1 33.5 6 1.35 12.59 0.85 201

33 6 1.35 9.31 0.47 198

32 6.5 1.35 15.46 0.77 208

30% T1 31 6 1.55 24.29 0.80 186

32 6 1.8 21.44 1.45 192

33 6.5 1.7 17.57 0.79 214.5

40% T1 31 7 1.6 34.45 0.58 217

32 6.5 1.5 33.09 1.21 208

33 6 1.5 21.19 1.48 198

50% T1 31 6 1.9 40.85 0.60 186

32 7 1.95 56.25 0.72 224

32 6 1.9 47.83 1.07 192

20% T2 32 6.5 2.5 32.35 0.69 208

32 6 2 49.06 0.58 192

33 6 2.4 31.11 1.01 198

30% T2 33 6 2.8 30.48 0.72 198

34 5.9 2.5 45.75 0.19 200.6

33 5.5 2.4 40.18 0.87 181.5

40% T2 32 6 2.2 139.26 0.83 192

33 6.5 2.4 92.20 0.56 214.5

32 7 2.5 72.02 0.55 224

50% T2 32.5 6.5 2.3 120.13 1.18 211.25

32 6 2.4 90.28 0.88 192

33 7 2.4 125.17 0.95 231

20% T3 33 6.5 3.2 60.03 0.75 214.5

32 6.2 3 49.56 0.39 198.4

33 6 3 61.05 0.48 198

30% T3 32 7 3.5 76.84 0.42 224

31.8 6.5 3.5 83.30 0.62 206.7

32.2 7 2.8 62.99 0.40 225.4

40% T3 32 7 3 132.56 1.00 224

33 6.5 3.4 96.43 0.70 214.5

31.6 6 3 88.11 0.61 189.6

50% T3 32 6 3.4 116.83 0.63 192

32 6 3.2 153.67 0.80 192

32 5.8 3.4 121.47 0.68 185.6

20% T4 33 6.5 4.4 71.09 0.38 214.5

33 6 3.8 65.62 0.48 198

32.5 6 4.2 73.81 0.53 195

30% T4 31.8 7 3.9 99.75 0.58 222.6

32 6.5 4.2 114.03 0.54 208

32 6 4.5 124.88 0.61 192

40% T4 32.6 6 4 180.71 1.04 195.6

33.2 7 4.6 112.29 0.56 232.4

33.4 6.3 4.8 129.32 0.78 210.42

50% T4 33 6.5 3.5 111.72 0.54 214.5

32 7 4.2 106.23 0.52 224

32 7 4.5 144.42 0.75 224

20% T5 33 6 4.8 64.43 0.42 198

32 6.5 5 118.95 0.59 208

32 6 5.4 78.69 0.48 192

30% T5 33 6.5 6 130.66 0.57 214.5

32 6 5.5 108.82 0.64 192

34 6 4.8 125.92 0.62 204

40% T5 33 6.5 5 125.79 0.83 214.5

32.8 6.5 5.2 159.07 0.92 213.2

32 7 5.5 144.85 0.86 224

50% T5 33.2 6.8 6 207.68 0.87 225.76

33 6.5 6.2 186.31 0.64 214.5

32 7 5.5 291.33 1.15 224

Alkali 8 jam

Alkali 8 jam panjang awal


20% T1 33.5 6 1.35 10.27 0.50 201

33 6 1.35 13.35 0.70 198

32 6.5 1.35 13.81 0.90 208

30% T1 31 6 1.55 30.63 0.67 186

32 6 1.8 19.22 0.79 192

33 6.5 1.7 23.46 0.51 214.5

40% T1 31 7 1.6 34.70 0.92 217

32 6.5 1.5 11.78 1.16 208

33 6 1.5 25.72 0.88 198

50% T1 31 6 1.9 45.01 0.73 186

32 7 1.95 33.42 0.48 224

32 6 1.9 29.98 0.42 192

20% T2 32 6.5 2.5 14.72 1.25 208

32 6 2 35.54 0.37 192

33 6 2.4 37.12 0.60 198

30% T2 33 6 2.8 55.00 0.55 198

34 5.9 2.5 41.10 0.49 200.6

33 5.5 2.4 38.10 0.48 181.5

40% T2 32 6 2.2 89.79 0.59 192

33 6.5 2.4 74.64 0.46 214.5

32 7 2.5 68.48 0.58 224

50% T2 32.5 6.5 2.3 80.15 0.50 211.25

32 6 2.4 84.61 0.52 192

33 7 2.4 78.18 0.68 231

20% T3 33 6.5 3.2 45.11 0.35 214.5

32 6.2 3 71.02 0.47 198.4

33 6 3 50.15 0.77 198

30% T3 32 7 3.5 84.17 0.75 224

31.8 6.5 3.5 71.81 0.56 206.7

32.2 7 2.8 65.18 0.47 225.4

40% T3 32 7 3 98.74 0.78 224

33 6.5 3.4 82.27 0.56 214.5

31.6 6 3 91.63 0.56 189.6

50% T3 32 6 3.4 143.88 0.81 192

32 6 3.2 161.82 0.90 192

32 5.8 3.4 144.87 0.79 185.6

20% T4 33 6.5 4.4 73.54 0.47 214.5

33 6 3.8 61.84 0.48 198

32.5 6 4.2 70.59 0.39 195

30% T4 31.8 7 3.9 78.84 0.48 222.6

32 6.5 4.2 92.61 0.58 208

32 6 4.5 89.34 0.57 192

40% T4 32.6 6 4 135.75 0.63 195.6

33.2 7 4.1 131.02 0.62 232.4

33.4 6.3 4.2 103.38 0.45 210.42

50% T4 33 6.5 4 196.27 1.06 214.5

32 6.4 4.2 286.62 1.52 204.8

32 6.5 4.5 159.26 0.87 208

20% T5 33 6 4.8 131.07 0.50 198

32 6.5 5 99.55 0.41 208

32 6 5.4 114.77 0.49 192

30% T5 33 6.5 6 108.42 0.45 214.5

32 6 5.5 128.26 0.53 192

34 6 4.8 141.13 0.62 204

40% T5 33 6.5 5 195.08 0.81 214.5

32.8 6.5 5.2 164.91 0.73 213.2

32 7 5.5 166.88 0.62 224

50% T5 33.2 6 5.5 134.14 0.75 199.2

33 6.5 5 166.02 0.71 214.5

32 6 5 143.77 0.60 192

Tabel.2.3.Data Pengujian Impak Alkali 2 jam

Jenis komposit

No Spesimen

Tebal (mm)

Lebar (mm)

Luas penampang

dibawah takik (mm²)

Harga impak

(J/mm²)

Volume I/T1-20/1 1.25 4.55 5.69 0.4

20% I/T1-20/2 1.3 4.35 5.66 0.4

I/T1-20/3 1.2 5.05 6.06 0.5

Volume I/T1-30/1 1.25 5.5 6.88 0.5

30% I/T1-30/2 1.55 5.7 8.84 0.4

I/T1-30/3 1.5 5.75 8.63 0.5

Volume I/T1-40/1 2.15 5.75 12.36 0.6

40% I/T1-40/2 2.15 4.85 10.43 0.6

I/T1-40/3 2.15 4.9 10.54 0.7

Volume I/T1-50/1 1.95 4.55 8.87 0.8

50% I/T1-50/2 2.2 5.65 12.43 0.7

I/T1-50/3 1.7 5.1 8.67 0.7

Volume I/T2-20/1 2.1 4.8 10.08 0.8

20% I/T2-20/2 2.1 5.3 11.13 1

I/T2-20/3 2.1 5.1 10.71 0.8

Volume I/T2-30/1 2.55 6.15 15.68 0.8

30% I/T2-30/2 2.6 6.15 15.99 0.7

I/T2-30/3 2.65 5.85 15.50 0.8

Volume I/T2-40/1 2.95 5.2 15.34 0.7

40% I/T2-40/2 2.8 5.5 15.40 0.5

I/T2-40/3 3 5.95 17.85 0.6

Volume I/T2-50/1 3.55 5.25 18.64 1

50% I/T2-50/2 3.75 5.25 19.69 0.9

I/T2-50/3 3.75 5.2 19.50 1

Volume I/T3-20/1 3.3 5.35 17.66 1

20% I/T3-20/2 3.15 5.25 16.54 1.1

I/T3-20/3 3.2 4.95 15.84 1.1

Volume I/T3-30/1 4.15 5.15 21.37 1.2

30% I/T3-30/2 3.3 5.4 17.82 1.1

I/T3-30/3 3.4 5.05 17.17 1.1

Volume I/T3-40/1 4.1 5.4 22.14 1.1

40% I/T3-40/2 3.05 5.5 16.78 1.1

I/T3-40/3 4.05 5.15 20.86 1.3

Volume I/T3-50/1 4.35 4.95 21.53 1

50% I/T3-50/2 4.2 5.3 22.26 1.1

I/T3-50/3 3.8 5.8 22.04 1.1

Volume I/T4-20/1 3.95 4.95 19.55 1.4

20% I/T4-20/2 4.05 5.25 21.26 1.4

I/T4-20/3 4.05 5.1 20.66 1.5

Volume I/T4-30/1 4.5 6 27.00 1.1

30% I/T4-30/2 4.4 5.35 23.54 1.1

I/T4-30/3 4.2 5.65 23.73 1.2

Volume I/T4-40/1 4.4 5.85 25.74 1.2

40% I/T4-40/2 4.1 6.2 25.42 1.3

I/T4-40/3 3.95 6.35 25.08 1.3

Volume I/T4-50/1 4.75 5.95 28.26 1.5

50% I/T4-50/2 4.2 5.55 23.31 1.6

I/T4-50/3 4.5 4.45 20.03 1.4

Volume I/T5-20/1 5.2 5.7 29.64 1.7

20% I/T5-20/2 5.4 5.3 28.62 1.7

I/T5-20/3 5 5.25 26.25 1.6

Volume I/T5-30/1 5.3 5.55 29.42 1.6

30% I/T5-30/2 5.5 4.9 26.95 1.7

I/T5-30/3 5.2 5.15 26.78 1.6

Volume I/T5-40/1 5.4 5.2 28.08 1.7

40% I/T5-40/2 5.1 5.25 26.78 1.8

I/T5-40/3 5.2 5.75 29.90 1.7

Volume I/T5-50/1 5.1 5.5 28.05 1.8

50% I/T5-50/2 5 5.55 27.75 1.7

I/T5-50/3 5 6 30 1.6

Alkali 4 jam

Jenis komposit

No Spesimen

Tebal (mm)

Lebar (mm)

Luas penampang


Harga impak

(J/mm²)

Volume I/T1-20/1 1 5 6.24 0.5

20% I/T1-20/2 1.25 4.55 5.69 0.6

I/T1-20/3 1.2 5.05 6.06 0.4

Volume I/T1-30/1 1.25 5.5 6.88 0.5

30% I/T1-30/2 1.55 5.7 8.84 0.5

I/T1-30/3 1.5 5.75 8.63 0.6

Volume I/T1-40/1 2.15 5.75 12.36 0.7

40% I/T1-40/2 2.15 4.85 10.43 0.6

I/T1-40/3 2.15 4.9 10.54 0.7

Volume I/T1-50/1 1.95 4.55 8.87 0.8

50% I/T1-50/2 2.2 5.65 12.43 0.7

I/T1-50/3 1.7 5.1 8.67 0.8

Volume I/T2-20/1 2.1 4.8 10.08 0.8

20% I/T2-20/2 2.1 5.3 11.13 0.8

I/T2-20/3 2.1 5.1 10.71 0.9

Volume I/T2-30/1 2.55 6.15 15.68 0.9

30% I/T2-30/2 2.6 6.15 15.99 0.8

I/T2-30/3 2.65 5.85 15.50 0.7

Volume I/T2-40/1 2.95 5.2 15.34 0.8

40% I/T2-40/2 2.8 5.5 15.40 0.7

I/T2-40/3 3 5.95 17.85 0.6

Volume I/T2-50/1 3.55 5.25 18.64 0.9

50% I/T2-50/2 3.75 5.25 19.69 1

I/T2-50/3 3.75 5.2 19.50 1.1

Volume I/T3-20/1 3.3 5.35 17.66 1.1

20% I/T3-20/2 3.15 5.25 16.54 1.1

I/T3-20/3 3.2 4.95 15.84 1.2

Volume I/T3-30/1 4.15 5.15 21.37 1.3

30% I/T3-30/2 3.3 5.4 17.82 1.1

I/T3-30/3 3.4 5.05 17.17 1.3

Volume I/T3-40/1 4.1 5.4 22.14 1.1

40% I/T3-40/2 3.05 5.5 16.78 1

I/T3-40/3 4.05 5.15 20.86 1.1

Volume I/T3-50/1 4.35 4.95 21.53 1.4

50% I/T3-50/2 4.2 5.3 22.26 1.4

I/T3-50/3 3.8 5.8 22.04 1.5

Volume I/T4-20/1 3.95 4.95 19.55 1.5

20% I/T4-20/2 4.05 5.25 21.26 1.4

I/T4-20/3 4.05 5.1 20.66 1.5

Volume I/T4-30/1 4.5 6 27.00 1.1

30% I/T4-30/2 4.4 5.35 23.54 1.3

I/T4-30/3 4.2 5.65 23.73 1.3

Volume I/T4-40/1 4.4 5.85 25.74 1.4

40% I/T4-40/2 4.1 6.2 25.42 1.6

I/T4-40/3 3.95 6.35 25.08 1.6

Volume I/T4-50/1 4.75 5.95 28.26 1.7

50% I/T4-50/2 4.2 5.55 23.31 1.5

I/T4-50/3 4.5 4.45 20.03 1.5

Volume I/T5-20/1 5.2 5.7 29.64 1.4

20% I/T5-20/2 5.4 5.3 28.62 1.5

I/T5-20/3 5 5.25 26.25 1.5

Volume I/T5-30/1 5.3 5.55 29.42 1.5

30% I/T5-30/2 5.5 4.9 26.95 1.7

I/T5-30/3 5.2 5.15 26.78 1.7

Volume I/T5-40/1 5.4 5.2 28.08 1.8

40% I/T5-40/2 5.1 5.25 26.78 1.7

I/T5-40/3 5.2 5.75 29.90 1.8

Volume I/T5-50/1 5.1 5.5 28.05 1.8

50% I/T5-50/2 5 5.55 27.75 1.7

I/T5-50/3 5 6 30 1.8

Alkali 6 jam

Jenis komposit

No Spesimen

Tebal (mm)

Lebar (mm)

Luas penampang


Harga impak

(J/mm²)

Volume I/T1-20/1 1 5 6.24 0.6

20% I/T1-20/2 1.25 4.55 5.69 0.5

I/T1-20/3 1.2 5.2 6.24 0.5

Volume I/T1-30/1 1.25 5.5 6.88 0.6

30% I/T1-30/2 1.55 5.7 8.84 0.5

I/T1-30/3 1.5 5.75 8.63 0.4

Volume I/T1-40/1 2.15 5.75 12.36 0.5

40% I/T1-40/2 1.75 4.85 8.49 0.6

I/T1-40/3 1.95 4.9 9.56 0.6

Volume I/T1-50/1 1.95 4.55 8.87 0.6

50% I/T1-50/2 2.1 5.65 11.87 0.8

I/T1-50/3 1.7 5.1 8.67 0.7

Volume I/T2-20/1 2.1 4.8 10.08 0.9

20% I/T2-20/2 2.1 5.3 11.13 0.8

I/T2-20/3 2.1 5.1 10.71 1

Volume I/T2-30/1 2.55 6.15 15.68 0.7

30% I/T2-30/2 2.6 6.15 15.99 0.8

I/T2-30/3 2.65 5.85 15.50 0.7

Volume I/T2-40/1 2.95 5.2 15.34 0.7

40% I/T2-40/2 2.8 5.5 15.40 0.8

I/T2-40/3 2.7 5.95 16.07 0.9

Volume I/T2-50/1 2.85 5.25 14.96 1.1

50% I/T2-50/2 2.55 5.25 13.39 1.1

I/T2-50/3 2.56 5.2 13.31 1.2

Volume I/T3-20/1 3.3 5.35 17.66 1

20% I/T3-20/2 3.15 5.25 16.54 1.1

I/T3-20/3 3.2 4.95 15.84 0.9

Volume I/T3-30/1 4.15 5.15 21.37 1.2

30% I/T3-30/2 3.3 5.4 17.82 1.3

I/T3-30/3 3.4 5.05 17.17 1.3

Volume I/T3-40/1 4.1 5.4 22.14 1.3

40% I/T3-40/2 3.05 5.5 16.78 1.3

I/T3-40/3 4.05 5.15 20.86 1.2

Volume I/T3-50/1 4.35 4.95 21.53 1.4

50% I/T3-50/2 4.2 5.3 22.26 1.3

I/T3-50/3 3.8 5.8 22.04 1.3

Volume I/T4-20/1 3.95 4.95 19.55 1.3

20% I/T4-20/2 4.05 5.25 21.26 1.2

I/T4-20/3 4.05 5.1 20.66 1.2

Volume I/T4-30/1 4.5 6 27.00 1.3

30% I/T4-30/2 4.4 5.35 23.54 1.2

I/T4-30/3 4.2 5.65 23.73 1.3

Volume I/T4-40/1 4.4 5.85 25.74 1.6

40% I/T4-40/2 4.1 6.2 25.42 1.5

I/T4-40/3 3.95 6.35 25.08 1.5

Volume I/T4-50/1 4.75 5.95 28.26 1.8

50% I/T4-50/2 4.2 5.55 23.31 1.7

I/T4-50/3 4.5 4.45 20.03 1.7

Volume I/T5-20/1 5.2 5.7 29.64 1.7

20% I/T5-20/2 5.4 5.3 28.62 1.5

I/T5-20/3 5 5.25 26.25 1.5

Volume I/T5-30/1 5.3 5.55 29.42 1.6

30% I/T5-30/2 5.5 4.9 26.95 1.7

I/T5-30/3 5.2 5.15 26.78 1.7

Volume I/T5-40/1 5.4 5.2 28.08 1.7

40% I/T5-40/2 5.1 5.25 26.78 1.6

I/T5-40/3 5.2 5.75 29.90 1.8

Volume I/T5-50/1 5.1 5.5 28.05 1.8

50% I/T5-50/2 5.4 5.55 29.97 1.8

I/T5-50/3 5 5.65 28.25 1.9

Alkali 8 jam

Jenis komposit

No Spesimen

Tebal (mm)

Lebar (mm)

Luas penampang


Harga impak

(J/mm²)

Volume I/T1-20/1 1.50 5.25 7.88 0.4

20% I/T1-20/2 1.25 4.85 6.06 0.6

I/T1-20/3 1.2 5.40 6.48 0.6

Volume I/T1-30/1 1.25 5.5 6.88 0.4

30% I/T1-30/2 1.55 5.7 8.84 0.6

I/T1-30/3 1.5 5.75 8.63 0.6

Volume I/T1-40/1 2.15 5.75 12.36 0.6

40% I/T1-40/2 1.75 4.85 8.49 0.7

I/T1-40/3 1.95 4.9 9.56 0.5

Volume I/T1-50/1 1.95 4.55 8.87 0.8

50% I/T1-50/2 2.10 5.65 11.87 0.9

I/T1-50/3 1.7 5.1 8.67 0.7

Volume I/T2-20/1 2.1 4.80 10.08 0.7

20% I/T2-20/2 2.1 5.3 11.13 0.9

I/T2-20/3 2.1 5.1 10.71 0.9

Volume I/T2-30/1 2.55 6.15 15.68 0.8

30% I/T2-30/2 2.6 6.15 15.99 1.1

I/T2-30/3 2.65 5.85 15.50 1

Volume I/T2-40/1 2.95 5.2 15.34 0.9

40% I/T2-40/2 2.8 5.5 15.40 0.8

I/T2-40/3 2.70 5.95 16.07 0.6

Volume I/T2-50/1 2.85 5.25 14.96 1

50% I/T2-50/2 2.55 5.25 13.39 0.9

I/T2-50/3 2.56 5.2 13.31 0.9

Volume I/T3-20/1 3.3 5.35 17.66 1.1

20% I/T3-20/2 3.15 5.25 16.54 1.1

I/T3-20/3 3.2 4.95 15.84 1.2

Volume I/T3-30/1 4.15 5.15 21.37 1.1

30% I/T3-30/2 3.3 5.4 17.82 1.2

I/T3-30/3 3.4 5.05 17.17 1.2

Volume I/T3-40/1 4.1 5.4 22.14 1.2

40% I/T3-40/2 3.05 5.5 16.78 1.3

I/T3-40/3 4.05 5.15 20.86 1.2

Volume I/T3-50/1 4.35 4.95 21.53 1.4

50% I/T3-50/2 4.2 5.3 22.26 1.3

I/T3-50/3 3.8 5.8 22.04 1.4

Volume I/T4-20/1 3.95 4.95 19.55 1.2

20% I/T4-20/2 4.05 5.25 21.26 1.1

I/T4-20/3 4.05 5.1 20.66 1.1

Volume I/T4-30/1 4.5 6.00 27.00 1.4

30% I/T4-30/2 4.4 5.35 23.54 1.5

I/T4-30/3 4.2 5.65 23.73 1.4

Volume I/T4-40/1 4.4 5.85 25.74 1.5

40% I/T4-40/2 4.1 6.2 25.42 1.4

I/T4-40/3 3.95 6.35 25.08 1.4

Volume I/T4-50/1 4.75 5.95 28.26 1.8

50% I/T4-50/2 4.2 5.55 23.31 1.6

I/T4-50/3 4.5 4.45 20.03 1.7

Volume I/T5-20/1 5.2 5.7 29.64 1.6

20% I/T5-20/2 5.4 5.3 28.62 1.7

I/T5-20/3 5.00 5.25 26.25 1.6

Volume I/T5-30/1 5.3 5.55 29.42 1.7

30% I/T5-30/2 5.5 4.9 26.95 1.6

I/T5-30/3 5.2 5.15 26.78 1.5

Volume I/T5-40/1 5.4 5.2 28.08 1.8

40% I/T5-40/2 5.1 5.25 26.78 1.7

I/T5-40/3 5.2 5.75 29.90 1.5

Volume I/T5-50/1 5.1 5.00 25.50 1.9

50% I/T5-50/2 5.25 5.45 28.61 1.7

I/T5-50/3 5.20 5.50 28.6 1.6

LAMPIRAN III

1. Pengujian Bending (Standart ASTM D 790-02)

Diketahui :

Tebal spesimen (d) : 1,35 mm

Lebar spesimen (b) : 12,00 mm

Panjang span (L) : 25,4 mm

Gaya (P) : 0,05 kN = 50 N

Penambahan panjang (∆L mesin) : 4,68 mm

a. Defleksi

kotak

Lmesin

78,06

68,4

kotak

mm mm (nilai per kotak)

= 2,5 kotak x 0,78 = 1,95 mm

b. Momen bending

Mb = 4

PL

= mm

mmN

4

4,2550

=317,5 N

c. Tegangan bending

22

3

bd

PL

2

35,1122

4,25503

mmmm

mmN

L

½ L

P

P/2 P/2

374,43

.3810

mm

mmN

= 87,1056 N/mm2

d. Modulus elastisitas bending

3

3

4bd

PLE

mmmmmm

mmN

95,135,1124

)4,25(503

3

5

3

2911,230

.2,819353

mm

mmN

= 3557,902 N/mm2

e. Kekakuan bending (Lukasen, 1975)

I = 1/12 x b x h3

= 1/12 x 12 mm x (1,35 mm)3

= 2,460 mm4

D = E x I

= 3557,902N/mm2 x 2,460 mm4

= 8753,773 Nmm2

2. Pengujian Impak (Standart ASTM D 256-00)

Diketahui :

Tebal spesimen (d) : 1,25mm

Lebar spesimen (b) : 4,55mm

Luas (Ao) : 5,7 mm2

Energi Terpasang : 21 J

Sudut α : 300

Sudut β : 29,50

Panjang Lengan (R) : 0,8 m

Percepatan gravitasi (g) : 10 m/s2

Berat Pendulum (m) : 20 kg

a. Esrp = mg.R.(cos β - cos α)

= 20kg. 10 m/s2 0,8 m(cos 29,5- cos 30)

= 160 kgm2/s2 (0,87-0,866)

= 0,69 kgm2/s2= 0,7 J

b. HI = Ao

Eserap

= 27,5

7,0

mm

J

= 0,122 J/mm2

3. Pengujian Tarik ( Standart ASTM D 638-02)

Diketahui :

Tebal spesimen (d) : 1,35mm

Lebar spesimen (b) : 6 mm

Panjang specimen (lo) : 33 mm

Luas (A) : 198 mm2

Beban (P) :148,10 N

Regangan () :0,71 mm/mm

a. Tegangan Tarik

P= σ . A atau σ = P/A

=148,10 N / 198 mm2

=0,748 Mpa

b. Regangan Tarik

= lo

L atau ΔL = x lo

= 0,71 x 33

=23,43 mm

c. Modulus elastisitas tarik

E =

= 0,748 Mpa / 0,71 mm/mm

=1,048 Mpa.

Data Hasil Pengujian Impak Serat Rami Alkali 2 jam

Jenis komposit

No Spesimen

Harga impak

(J/mm²)

Harga impak

rata-rata (j/mm²)

Energi yang

terserap (J)

Energi yang

terserap rata-rata

(J)

Volume I/T1-20/1 0.4 2.28

20% I/T1-20/2 0.4 0.433 2.26 2.522

I/T1-20/3 0.5 3.03

Volume I/T1-30/1 0.5 3.44

30% I/T1-30/2 0.4 0.467 3.53 3.761

I/T1-30/3 0.5 4.31

Volume I/T1-40/1 0.6 7.42

40% I/T1-40/2 0.6 0.700 6.26 7.016

I/T1-40/3 0.7 7.37

Volume I/T1-50/1 0.8 7.10

50% I/T1-50/2 0.7 0.733 8.70 7.289

I/T1-50/3 0.7 6.07

Volume I/T2-20/1 0.8 8.06

20% I/T2-20/2 1 0.867 11.13 9.254

I/T2-20/3 0.8 8.57

Volume I/T2-30/1 0.8 12.55

30% I/T2-30/2 0.7 0.767 11.19 12.047

I/T2-30/3 0.8 12.40

Volume I/T2-40/1 0.7 10.74

40% I/T2-40/2 0.5 0.600 7.70 9.716

I/T2-40/3 0.6 10.71

Volume I/T2-50/1 1 18.64

50% I/T2-50/2 0.9 0.967 17.72 18.619

I/T2-50/3 1 19.50

Volume I/T3-20/1 1 17.66

20% I/T3-20/2 1.1 1.067 18.19 17.757

I/T3-20/3 1.1 17.42

Volume I/T3-30/1 1.2 25.65

30% I/T3-30/2 1.1 1.133 19.60 21.379

I/T3-30/3 1.1 18.89

Volume I/T3-40/1 1.1 24.35

40% I/T3-40/2 1.1 1.167 18.45 23.307

I/T3-40/3 1.3 27.11

Volume I/T3-50/1 1 21.53

50% I/T3-50/2 1.1 1.067 24.49 23.421

I/T3-50/3 1.1 24.24

Volume I/T4-20/1 1.4 27.37

20% I/T4-20/2 1.4 1.433 29.77 29.375

I/T4-20/3 1.5 30.98

Volume I/T4-30/1 1.1 29.70

30% I/T4-30/2 1.1 1.133 25.89 28.023

I/T4-30/3 1.2 28.48

Volume I/T4-40/1 1.2 30.89

40% I/T4-40/2 1.3 1.267 33.05 32.180

I/T4-40/3 1.3 32.61

Volume I/T4-50/1 1.5 42.39

50% I/T4-50/2 1.6 1.500 37.30 35.908

I/T4-50/3 1.4 28.04

Volume I/T5-20/1 1.7 50.39

20% I/T5-20/2 1.7 1.667 48.65 47.014

I/T5-20/3 1.6 42.00

Volume I/T5-30/1 1.6 47.06

30% I/T5-30/2 1.7 1.633 45.82 45.242

I/T5-30/3 1.6 42.85

Volume I/T5-40/1 1.7 47.74

40% I/T5-40/2 1.8 1.733 48.20 48.920

I/T5-40/3 1.7 50.83

Volume I/T5-50/1 1.8 50.49

50% I/T5-50/2 1.7 1.700 47.18 48.555

I/T5-50/3 1.6 48.00


Jenis komposit

No Spesimen

Harga impak

(J/mm²)

Harga impak

rata-rata (j/mm²)

Energi yang

terserap (J)

Energi yang

terserap rata-rata

(J)

Volume I/T1-20/1 0.5 3.12

20% I/T1-20/2 0.6 0.500 3.41 3.188

I/T1-20/3 0.4 3.03

Volume I/T1-30/1 0.5 3.44

30% I/T1-30/2 0.5 0.533 4.42 4.343

I/T1-30/3 0.6 5.18

Volume I/T1-40/1 0.7 8.65

40% I/T1-40/2 0.6 0.700 6.26 7.428

I/T1-40/3 0.7 7.37

Volume I/T1-50/1 0.8 7.10

50% I/T1-50/2 0.7 0.767 8.70 7.578

I/T1-50/3 0.8 6.94

Volume I/T2-20/1 0.8 8.06

20% I/T2-20/2 0.8 0.833 8.90 8.869

I/T2-20/3 0.9 9.64

Volume I/T2-30/1 0.9 14.11

30% I/T2-30/2 0.8 0.800 12.79 12.586

I/T2-30/3 0.7 10.85

Volume I/T2-40/1 0.8 12.27

40% I/T2-40/2 0.7 0.700 10.78 11.254

I/T2-40/3 0.6 10.71

Volume I/T2-50/1 0.9 16.77

50% I/T2-50/2 1 1.000 19.69 19.304

I/T2-50/3 1.1 21.45

Volume I/T3-20/1 1.1 19.42

20% I/T3-20/2 1.1 1.133 18.19 18.873

I/T3-20/3 1.2 19.01

Volume I/T3-30/1 1.3 27.78

30% I/T3-30/2 1.1 1.233 19.60 23.236

I/T3-30/3 1.3 22.32

Volume I/T3-40/1 1.1 24.35

40% I/T3-40/2 1 1.067 16.78 21.357

I/T3-40/3 1.1 22.94

Volume I/T3-50/1 1.4 30.15

50% I/T3-50/2 1.4 1.433 31.16 31.457

I/T3-50/3 1.5 33.06

Volume I/T4-20/1 1.5 29.33

20% I/T4-20/2 1.4 1.467 29.77 30.026

I/T4-20/3 1.5 30.98

Volume I/T4-30/1 1.1 29.70

30% I/T4-30/2 1.3 1.233 30.60 30.384

I/T4-30/3 1.3 30.85

Volume I/T4-40/1 1.4 36.04

40% I/T4-40/2 1.6 1.533 40.67 38.947

I/T4-40/3 1.6 40.13

Volume I/T4-50/1 1.7 48.05

50% I/T4-50/2 1.5 1.567 34.97 37.683

I/T4-50/3 1.5 30.04

Volume I/T5-20/1 1.4 41.50

20% I/T5-20/2 1.5 1.467 42.93 41.267

I/T5-20/3 1.5 39.38

Volume I/T5-30/1 1.5 44.12

30% I/T5-30/2 1.7 1.633 45.82 45.155

I/T5-30/3 1.7 45.53

Volume I/T5-40/1 1.8 50.54

40% I/T5-40/2 1.7 1.767 45.52 49.961

I/T5-40/3 1.8 53.82

Volume I/T5-50/1 1.8 50.49

50% I/T5-50/2 1.7 1.767 47.18 50.555

I/T5-50/3 1.8 54.00


Jenis komposit

No Spesimen

Harga impak

(J/mm²)

Harga impak

rata-rata (j/mm²)

Energi yang

terserap (J)

Energi yang

terserap rata-rata

(J)

Volume I/T1-20/1 0.6 3.74

20% I/T1-20/2 0.5 0.533 2.84 3.206

I/T1-20/3 0.5 3.03

Volume I/T1-30/1 0.6 4.13

30% I/T1-30/2 0.5 0.500 4.42 3.998

I/T1-30/3 0.4 3.45

Volume I/T1-40/1 0.5 6.18

40% I/T1-40/2 0.6 0.600 5.09 5.669

I/T1-40/3 0.6 5.73

Volume I/T1-50/1 0.6 5.32

50% I/T1-50/2 0.8 0.700 9.49 6.962

I/T1-50/3 0.7 6.07

Volume I/T2-20/1 0.9 9.07

20% I/T2-20/2 0.8 0.900 8.90 9.562

I/T2-20/3 1 10.71

Volume I/T2-30/1 0.7 10.98

30% I/T2-30/2 0.8 0.733 12.79 11.541

I/T2-30/3 0.7 10.85

Volume I/T2-40/1 0.7 10.74

40% I/T2-40/2 0.8 0.800 12.32 12.506

I/T2-40/3 0.9 14.46

Volume I/T2-50/1 1.1 16.46

50% I/T2-50/2 1.1 1.133 14.73 15.720

I/T2-50/3 1.2 15.97

Volume I/T3-20/1 1 17.66

20% I/T3-20/2 1.1 1.000 18.19 16.701

I/T3-20/3 0.9 14.26

Volume I/T3-30/1 1.2 25.65

30% I/T3-30/2 1.3 1.267 23.17 23.711

I/T3-30/3 1.3 22.32

Volume I/T3-40/1 1.3 28.78

40% I/T3-40/2 1.3 1.267 21.81 25.206

I/T3-40/3 1.2 25.03

Volume I/T3-50/1 1.4 30.15

50% I/T3-50/2 1.3 1.333 28.94 29.245

I/T3-50/3 1.3 28.65

Volume I/T4-20/1 1.3 25.42

20% I/T4-20/2 1.2 1.233 25.52 25.240

I/T4-20/3 1.2 24.79

Volume I/T4-30/1 1.3 35.10

30% I/T4-30/2 1.2 1.267 28.25 31.399

I/T4-30/3 1.3 30.85

Volume I/T4-40/1 1.6 41.18

40% I/T4-40/2 1.5 1.533 38.13 38.979

I/T4-40/3 1.5 37.62

Volume I/T4-50/1 1.8 50.87

50% I/T4-50/2 1.7 1.733 39.63 41.514

I/T4-50/3 1.7 34.04

Volume I/T5-20/1 1.7 50.39

20% I/T5-20/2 1.5 1.567 42.93 44.231

I/T5-20/3 1.5 39.38

Volume I/T5-30/1 1.6 47.06

30% I/T5-30/2 1.7 1.667 45.82 46.135

I/T5-30/3 1.7 45.53

Volume I/T5-40/1 1.7 47.74

40% I/T5-40/2 1.6 1.700 42.84 48.132

I/T5-40/3 1.8 53.82

Volume I/T5-50/1 1.8 50.49

50% I/T5-50/2 1.8 1.833 53.95 52.704

I/T5-50/3 1.9 53.68


Jenis komposit

No Spesimen

Harga impak

(J/mm²)

Harga impak

rata-rata (j/mm²)

Energi yang

terserap (J)

Energi yang

terserap rata-rata

(J)

Volume I/T1-20/1 0.4 3.15

20% I/T1-20/2 0.6 0.533 3.64 3.273

I/T1-20/3 0.6 3.03

Volume I/T1-30/1 0.4 2.75

30% I/T1-30/2 0.6 0.533 5.30 4.409

I/T1-30/3 0.6 5.18

Volume I/T1-40/1 0.6 7.42

40% I/T1-40/2 0.7 0.667 5.94 6.045

I/T1-40/3 0.5 4.78

Volume I/T1-50/1 0.8 7.10

50% I/T1-50/2 0.9 0.800 10.68 7.949

I/T1-50/3 0.7 6.07

Volume I/T2-20/1 0.7 7.06

20% I/T2-20/2 0.9 0.833 10.02 8.904

I/T2-20/3 0.9 9.64

Volume I/T2-30/1 0.8 12.55

30% I/T2-30/2 1.1 0.967 17.59 15.213

I/T2-30/3 1 15.50

Volume I/T2-40/1 0.9 13.81

40% I/T2-40/2 0.8 0.767 12.32 11.922

I/T2-40/3 0.6 9.64

Volume I/T2-50/1 1 14.96

50% I/T2-50/2 0.9 0.933 12.05 12.997

I/T2-50/3 0.9 11.98

Volume I/T3-20/1 1.1 19.42

20% I/T3-20/2 1.1 1.133 18.19 18.873

I/T3-20/3 1.2 19.01

Volume I/T3-30/1 1.1 23.51

30% I/T3-30/2 1.2 1.167 21.38 21.833

I/T3-30/3 1.2 20.60

Volume I/T3-40/1 1.2 26.57

40% I/T3-40/2 1.3 1.233 21.81 24.468

I/T3-40/3 1.2 25.03

Volume I/T3-50/1 1.4 30.15

50% I/T3-50/2 1.3 1.367 28.94 29.980

I/T3-50/3 1.4 30.86

Volume I/T4-20/1 1.2 23.46

20% I/T4-20/2 1.1 1.133 23.39 23.191

I/T4-20/3 1.1 22.72

Volume I/T4-30/1 1.4 37.80

30% I/T4-30/2 1.5 1.433 35.31 35.444

I/T4-30/3 1.4 33.22

Volume I/T4-40/1 1.5 38.61

40% I/T4-40/2 1.4 1.433 35.59 36.438

I/T4-40/3 1.4 35.12

Volume I/T4-50/1 1.8 50.87

50% I/T4-50/2 1.6 1.700 37.30 40.737

I/T4-50/3 1.7 34.04

Volume I/T5-20/1 1.6 47.42

20% I/T5-20/2 1.7 1.633 48.65 46.026

I/T5-20/3 1.6 42.00

Volume I/T5-30/1 1.7 50.01

30% I/T5-30/2 1.6 1.600 43.12 44.432

I/T5-30/3 1.5 40.17

Volume I/T5-40/1 1.8 50.54

40% I/T5-40/2 1.7 1.667 45.52 46.971

I/T5-40/3 1.5 44.85

Volume I/T5-50/1 1.9 48.45

50% I/T5-50/2 1.7 1.733 48.64 47.617

I/T5-50/3 1.6 45.76

Data Hasil Pengujian tarik Serat Rami Alkali 2 jam

specimen kek tarik Mod Elastisitas kek tarik rata2 Mod Elastisitas rata2

20% T1 0.748 1.048 0.662 0.797

0.813 0.650

0.425 0.694

30% T1 0.148 0.260 0.772 0.850

0.960 1.182

1.209 1.107

40% T1 1.117 1.814 0.906 1.174

0.894 0.801

0.707 0.907

50% T1 2.423 2.937 1.506 1.747

0.848 1.163

1.247 1.142

20% T2 1.289 3.106 1.348 3.297

1.439 3.370

1.314 3.414

30% T2 2.062 4.774 1.994 4.060

1.894 3.962

2.025 3.444

40% T2 3.805 6.300 2.523 4.875

1.752 3.504

2.010 4.821

50% T2 2.685 5.173 3.192 5.565

4.215 5.650

2.678 5.872

20% T3 2.867 4.952 2.193 5.924

2.032 6.432

1.680 6.389

30% T3 3.503 4.462 3.032 6.756

3.162 7.731

2.430 8.074

40% T3 2.790 5.158 4.686 28.560

5.136 6.644

6.132 73.879

50% T3 7.120 11.055 5.941 9.449

6.381 7.403

4.322 9.890

20% T4 4.872 5.685 4.353 5.208

3.436 3.878

4.752 6.061

30% T4 4.030 5.114 3.714 5.899

3.666 6.702

3.446 5.881

40% T4 6.399 5.011 6.018 4.782

5.808 4.520

5.847 4.816

50% T4 14.612 9.880 11.710 9.069

7.538 8.615

12.980 8.711

20% T5 6.933 4.352 8.399 5.884

9.011 6.506

9.254 6.795

30% T5 6.324 4.241 8.377 5.462

12.679 8.325

6.129 3.819

40% T5 7.351 5.148 9.423 6.341

11.556 7.756

9.362 6.119

50% T5 11.162 6.652 12.644 8.731

9.940 6.098

16.830 13.442


Spesimen kek tarik Mod Elastisitas kek tarik rata2 Mod Elastisitas rata2

20% T1 0.617 0.331 0.798 0.878

0.676 0.793

1.103 1.511

30% T1 0.604 0.829 0.755 0.956

0.790 1.013

0.872 1.026

40% T1 1.755 1.877 1.868 1.498

1.829 1.541

2.019 1.077

50% T1 1.437 2.525 1.483 2.025

1.320 1.693

1.690 1.858

20% T2 3.080 5.082 1.806 3.308

1.721 4.401

0.618 0.442

30% T2 2.574 2.579 1.663 1.563

1.014 0.839

1.400 1.272

40% T2 4.848 5.677 3.354 4.921

2.989 5.084

2.225 4.002

50% T2 4.810 6.737 4.769 7.103

4.654 6.013

4.844 8.559

20% T3 1.990 6.122 2.845 6.928

2.316 7.307

4.229 7.356

30% T3 3.610 5.529 3.787 5.942

4.049 5.945

3.703 6.352

40% T3 2.471 7.377 3.155 6.049

2.870 5.979

4.125 4.791

50% T3 8.656 8.316 7.613 10.019

7.385 9.128

6.798 12.613

20% T4 3.284 9.409 4.080 8.275

3.285 6.163

5.672 9.252

30% T4 3.651 6.096 4.972 7.385

4.869 8.587

6.395 7.471

40% T4 6.014 8.884 4.852 9.222

4.332 7.280

4.210 11.503

50% T4 8.134 6.315 6.983 8.919

6.910 10.581

5.907 9.861

20% T5 2.669 4.675 2.992 7.659

2.991 8.403

3.317 9.901

30% T5 3.618 9.884 4.530 9.801

4.183 9.254

5.789 10.265

40% T5 5.168 10.949 4.988 8.909

4.732 6.637

5.065 9.142

50% T5 10.123 8.857 9.581 12.244

9.386 13.927

9.234 13.948


Specimen kek tarik Mod Elastisitas kek tarik rata2 Mod Elastisitas rata2

20% T1 0.614 0.723 0.601 0.886

0.461 0.986

0.728 0.948

30% T1 1.280 1.608 1.059 1.128

1.094 0.756

0.803 1.021

40% T1 1.556 2.701 1.388 1.568

1.559 1.293

1.049 0.710

50% T1 2.152 3.587 2.352 3.096

2.461 3.418

2.441 2.282

20% T2 1.524 2.222 1.856 2.700

2.504 4.347

1.540 1.531

30% T2 1.508 2.110 1.971 5.536

2.235 12.017

2.169 2.482

40% T2 7.108 8.616 4.824 7.293

4.212 7.482

3.151 5.782

50% T2 5.573 4.743 5.164 5.205

4.608 5.266

5.310 5.608

20% T3 2.743 3.657 2.738 5.420

2.448 6.359

3.022 6.243

30% T3 3.362 7.947 3.350 7.040

3.950 6.360

2.739 6.812

40% T3 5.800 5.782 4.920 6.533

4.406 6.339

4.554 7.478

50% T3 5.963 9.421 6.740 9.554

7.843 9.780

6.414 9.460

20% T4 3.248 8.615 3.402 7.451

3.248 6.753

3.709 6.985

30% T4 4.391 7.598 5.379 9.314

5.373 9.913

6.374 10.432

40% T4 9.054 8.731 6.604 8.290

4.735 8.456

6.023 7.682

50% T4 5.104 9.453 5.357 8.917

4.647 8.886

6.319 8.414

20% T5 3.189 7.593 4.270 8.504

5.604 9.499

4.016 8.420

30% T5 5.970 10.473 5.858 9.652

5.554 8.679

6.049 9.804

40% T5 5.747 6.949 6.465 7.410

7.312 7.939

6.337 7.343

50% T5 9.015 10.398 10.091 11.638

8.512 13.404

12.746 11.112


Alkali 8 jam kek tarik Mod Elastisitas kek tarik rata2 Mod Elastisitas rata2

20% T1 0.501 1.011 0.604 0.895

0.661 0.948

0.651 0.725

30% T1 1.614 2.394 1.222 1.908

0.981 1.244

1.072 2.085

40% T1 1.567 1.709 1.132 1.213

0.555 0.478

1.273 1.453

50% T1 2.372 3.253 1.788 3.309

1.462 3.021

1.530 3.652

20% T2 0.693 0.555 1.448 2.825

1.814 4.877

1.837 3.042

30% T2 2.722 4.923 2.262 4.441

2.008 4.131

2.057 4.268

40% T2 4.583 7.716 3.663 6.784

3.410 7.462

2.996 5.174

50% T2 3.718 7.497 3.785 6.919

4.319 8.370

3.317 4.892

20% T3 2.061 5.956 2.684 5.557

3.508 7.480

2.482 3.236

30% T3 3.683 4.884 3.307 5.657

3.405 6.069

2.834 6.017

40% T3 4.320 5.510 4.272 6.898

3.759 6.712

4.736 8.472

50% T3 7.344 9.044 7.751 9.318

8.260 9.177

7.649 9.732

20% T4 3.360 7.088 3.323 7.485

3.061 6.363

3.548 9.004

30% T4 3.471 7.277 4.131 7.596

4.363 7.497

4.560 8.014

40% T4 6.801 10.864 5.713 10.160

5.525 8.868

4.815 10.747

50% T4 8.967 8.467 10.062 8.705

13.715 9.053

7.504 8.595

20% T5 6.487 13.079 5.679 12.173

4.690 11.412

5.858 12.029

30% T5 4.953 11.008 6.093 11.420

6.546 12.282

6.780 10.970

40% T5 8.913 11.058 7.931 11.122

7.580 10.456

7.301 11.852

50% T5 6.599 8.846 7.174 10.558

7.585 10.638

7.338 12.190

Data Pengujian Bending komposit serat rami

Tabel data hasil pengujian bending komposit serat rami pada alkali 2 jam tebal 1mm

Jenis No Spesimen

Defleksi Support span

Beban Momen Bending

Teg Bending Modulus elastisitas

Kekakuan

Komposit (mm) (mm) (N) (Nmm) (MPa) (MPa) (Nmm2)

Volume B/T1-20/1 2.16 25.4 31.89 202.5015 55.55596708 2048.610409 5040.3498

20% B/T1-20/2 2.456 25.4 35.42 224.917 56.74080381 1840.134364 4923.5699

B/T1-20/3 2.512 25.4 33.52 212.852 55.61486707 1763.411557 4555.5864

Volume B/T1-30/1 4.024 25.4 33.53 212.9155 44.49664096 767.1031041 2844.6936

30% B/T1-30/2 3.668 25.4 42.98 272.923 39.02802803 635.6103478 4000.3408

B/T1-30/3 2.945 25.4 31.51 200.0885 32.58107063 699.7571 3652.7758

Volume B/T1-40/1 5.898 25.4 36.35 230.8225 20.61436673 163.4005735 2104.067

40% B/T1-40/2 3.267 25.4 30.92 196.342 17.96923781 262.8537556 3231.099

B/T1-40/3 4.351 25.4 29.85 189.5475 16.16448967 173.6845796 2342.1525

Volume B/T1-50/1 1.309 25.4 95.37 605.5995 73.7389425 3188.011214 24873.222

50% B/T1-50/2 1.458 25.4 90.53 574.8655 69.50847522 2628.825805 21198.001

B/T1-50/3 1.422 25.4 97.36 618.236 79.65419056 3170.090161 23374.422


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T2-20/1 1.408 30 136.21 1021.575 111.6383903 5663.473534 54416.282

20% B/T2-20/2 2.203 30 115.02 862.65 92.05282113 2984.657971 29368.475

B/T2-20/3 1.945 30 127.48 956.1 99.28134127 3561.236609 36867.609

Volume B/T2-30/1 1.601 30 95.02 712.65 42.94452033 1436.976454 33384.603

30% B/T2-30/2 2.663 30 100.22 751.65 41.74702685 825.0889746 21169.264

B/T2-30/3 1.418 30 42.19 316.425 18.69976755 706.4691549 16736.16

Volume B/T2-40/1 1.104 30 92.44 693.3 43.82917915 2165.473278 47099.185

40% B/T2-40/2 1.177 30 64.33 482.475 29.10951199 1349.015771 30743.946

B/T2-40/3 0.803 30 58.17 436.275 28.72592593 1987.403205 40747.976

Volume B/T2-50/1 1.253 30 228.18 1711.35 69.31489095 2476.976723 102435.16

50% B/T2-50/2 2.515 30 205.07 1538.025 61.77784138 1067.989305 45865.557

B/T2-50/3 2.061 30 302.28 2267.1 92.18383093 2033.078182 82500


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T3-20/1 2.284 50 103.94 1299.25 55.91734519 3238.386266 118510.11

20% B/T3-20/2 4.057 50 116.27 1453.375 56.58384811 1816.043519 74633.093

B/T3-20/3 1.589 50 67.42 842.75 41.94233706 3491.458894 110492.71

Volume B/T3-30/1 2.997 50 140.44 1755.5 42.04763143 1313.661709 122031.75

30% B/T3-30/2 2.021 50 148.98 1862.25 45.43606176 2178.485484 191968.7

B/T3-30/3 1.621 50 86.68 1083.5 31.49892436 1927.756502 139253.03

Volume B/T3-40/1 2.391 50 373.12 4664 176.9332114 8685.407299 406385.06

40% B/T3-40/2 2.396 50 346.69 4333.625 140.6906907 6612.498434 376810.74

B/T3-40/3 1.991 50 298.23 3727.875 114.2544453 6462.326264 390075.65

Volume B/T3-50/1 3.318 50 204.37 2554.625 57.56090691 1606.303075 160401.91

50% B/T3-50/2 3.804 50 168.34 2104.25 54.01745604 1408.747268 115243.27

B/T3-50/3 1.371 50 49.73 621.625 13.40411998 885.5881125 94460.4


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T4-20/1 6.888 65 163.21 2652.1625 59.13317899 1373.918196 135566.52

20% B/T4-20/2 6.897 65 163.72 2660.45 68.24309628 1639.400375 135812.69

B/T4-20/3 7.279 65 188.65 3065.5625 75.83333333 1746.685035 148280.46

Volume B/T4-30/1 6.424 65 222.3 3612.375 77.25820997 1801.842035 197985.22

30% B/T4-30/2 7.386 65 150.87 2451.6375 52.26851983 1083.299467 116867.14

B/T4-30/3 6.645 65 177.56 2885.35 61.9531668 1396.838287 152879.4

Volume B/T4-40/1 25.6 65 114.29 1857.2125 29.38254474 151.0675277 25542.717

40% B/T4-40/2 15.276 65 138.43 2249.4875 31.33818412 265.0593562 51846.495

B/T4-40/3 16.03 65 109.69 1782.4625 26.40340474 208.9820045 39150.052

Volume B/T4-50/1 3.912 65 216.27 3514.3875 59.77709379 2089.316262 316297.87

50% B/T4-50/2 5.56 65 459.11 7460.5375 128.893856 3109.378448 472433.62

B/T4-50/3 5.02 65 470.19 7640.5875 146.7435966 4076.050225 535881.18


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T5-20/1 12.038 80 242.78 4855.6 71.36390359 1171.006276 215123.22

20% B/T5-20/2 5.406 80 120.54 2410.8 37.4607162 1356.226594 237839.44

B/T5-20/3 8.947 80 258 5160 67.68439201 1453.941173 307589.14

Volume B/T5-30/1 11.38 80 152.95 3059 51.62052418 921.6150717 143362.62

30% B/T5-30/2 14.523 80 210.32 4206.4 67.35520648 916.1145868 154473.13

B/T5-30/3 11.19 80 205.37 4107.4 71.53023129 1298.760175 195765.27

Volume B/T5-40/1 4.915 80 252.177 5043.54 66.40589268 2382.080566 547281.38

40% B/T5-40/2 3.194 80 198.111 3962.22 55.13293135 3287.886892 661610.52

B/T5-40/3 5.514 80 285.393 5707.86 80.92429112 2722.532174 552084.15

Volume B/T5-50/1 3.415 80 353.189 7063.78 65.59440982 2906.134616 1103177

50% B/T5-50/2 4.715 80 295.63 5912.6 58.38643845 1886.952513 668798.87

B/T5-50/3 5.171 80 289.74 5794.8 57.18025971 1734.568266 597671.63


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T1-20/1 1.922 25.4 36.24 230.124 63.13415638 2616.335371 6437.1661

20% B/T1-20/2 2.557 25.4 38.27 243.0145 61.30633997 1909.664503 5109.6087

B/T1-20/3 2.29 25.4 38.67 245.5545 64.15951401 2231.557068 5764.9906

Volume B/T1-30/1 2.37 25.4 31.42 199.517 41.69652428 1220.494969 4526.0333

30% B/T1-30/2 2.301 25.4 31.62 200.787 28.71256971 745.4167059 4691.4291

B/T1-30/3 2.028 25.4 28.35 180.0225 29.31365764 914.2591641 4772.49

Volume B/T1-40/1 3.013 25.4 39.06 248.031 22.15122873 343.7059392 4425.8126

40% B/T1-40/2 3.004 25.4 68.6 435.61 39.86706707 634.2318141 7796.2203

B/T1-40/3 2.18 25.4 77.13 489.7755 41.76774166 895.7211877 12078.882

Volume B/T1-50/1 6.988 25.4 87.11 553.1485 67.35240936 545.4598915 4255.7394

50% B/T1-50/2 2.591 25.4 74.03 470.0905 56.83985883 1209.670666 9754.393

B/T1-50/3 2.701 25.4 52.86 335.661 43.24692392 906.1356559 6681.3233


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T2-20/1 1.848 30 59.69 447.675 48.92221949 1890.933035 18168.628

20% B/T2-20/2 3.448 30 68.35 512.625 54.70188075 1133.201043 11150.486

B/T2-20/3 3.249 30 101.95 764.625 79.39859383 1704.966691 17650.623

Volume B/T2-30/1 3.748 30 80.83 606.225 36.53131528 522.154415 12130.97

30% B/T2-30/2 2.365 30 100.98 757.35 42.06360777 936.0989824 24017.442

B/T2-30/3 1.902 30 74.95 562.125 33.21989993 935.6664018 22165.812

Volume B/T2-40/1 1.421 30 222.85 1671.375 105.6613217 4055.83731 88214.726

40% B/T2-40/2 1.512 30 186.09 1395.675 84.20626591 3037.74408 69229.911

B/T2-40/3 2.157 30 341.92 2564.4 168.8493827 4348.87402 89165.508

Volume B/T2-50/1 1.859 30 304.98 2287.35 92.64464651 2231.451186 92281.469

50% B/T2-50/2 2.072 30 321.72 2412.9 96.9189405 2033.719584 87339.527

B/T2-50/3 2.225 30 355.54 2666.55 108.4260925 2215.037641 89883.708


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T3-20/1 4.806 50 146.74 1834.25 78.9427673 2172.73512 79512.155

20% B/T3-20/2 2.074 50 129.85 1623.125 63.19267805 3967.315954 163042.93

B/T3-20/3 0.893 50 50.95 636.875 31.69626332 4694.991516 148580.39

Volume B/T3-30/1 0.903 50 86.91 1086.375 26.02078929 2698.121253 250640.23

30% B/T3-30/2 1.375 50 85.42 1067.75 26.05147265 1835.90364 161780.3

B/T3-30/3 1.533 50 138.04 1725.5 50.16280016 3246.228487 234493.91

Volume B/T3-40/1 1.901 50 87.58 1094.75 41.53036732 2564.153739 119975.23

40% B/T3-40/2 3.489 50 172.66 2158.25 70.06736466 2261.52737 128872.29

B/T3-40/3 1.251 50 69.1 863.75 26.47279674 2383.030219 143843.26

Volume B/T3-50/1 0.777 50 186.51 2331.375 52.53062949 6259.906274 625100.55

50% B/T3-50/2 1.854 50 264.48 3306 84.86715441 4541.186924 371494.07

B/T3-50/3 1.482 50 236.11 2951.375 63.64059456 3889.707564 414891.9


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T4-20/1 3.772 65 137.26 2230.475 49.73114484 2109.98593 208195.41

20% B/T4-20/2 2.188 65 95.82 1557.075 39.9404684 3024.491504 250557.66

B/T4-20/3 4.607 65 135.74 2205.775 54.56462585 1985.725175 168573.17

Volume B/T4-30/1 3.598 65 213.36 3467.1 58.9727689 2241.086369 339274.08

30% B/T4-30/2 5.242 65 270.81 4400.6625 76.02915452 1945.356963 295574.19

B/T4-30/3 3.665 65 217.39 3532.5875 67.84616954 2581.281918 339362.94

Volume B/T4-40/1 3.366 65 290.53 4721.1125 74.69166789 2920.651418 493827.99

40% B/T4-40/2 4.4 65 324.33 5270.3625 73.42276425 2156.040999 421728.82

B/T4-40/3 2.082 65 227 3688.75 54.64101446 3329.81809 623797.98

Volume B/T4-50/1 3.327 65 222.3 3612.375 77.25820997 3479.120298 382283.45

50% B/T4-50/2 2.678 65 311.87 5067.8875 108.0465519 6176.15192 666287.8

B/T4-50/3 2.152 65 226.63 3682.7375 79.07437594 5505.174773 602523.46


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T5-20/1 4.921 80 102.43 2048.6 30.10875955 1208.577382 222025.33

20% B/T5-20/2 4.929 80 107.22 2144.4 33.32120451 1323.104344 232030.84

B/T5-20/3 9.253 80 170.22 3404.4 44.65595817 927.5398784 196226.09

Volume B/T5-30/1 7.774 80 186.52 3730.4 62.95037705 1645.217118 255923.16

30% B/T5-30/2 5.365 80 251.82 5036.4 80.64562617 2969.24515 500667.29

B/T5-30/3 7.899 80 191.89 3837.8 66.83515646 1719.104493 259124.78

Volume B/T5-40/1 2.87 80 306.15 6123 56.85830693 2997.447833 1137839.7

40% B/T5-40/2 3.851 80 324.51 6490.2 64.09019092 2535.99697 898841.86

B/T5-40/3 2.012 80 363.2 7264 71.67760864 5588.243764 1925513.6

Volume B/T5-50/1 3.696 80 395.77 7915.4 104.2183076 4971.476635 1142193.4

50% B/T5-50/2 4.579 80 430.72 8614.4 119.8664193 4986.175784 1003351.5

B/T5-50/3 4.303 80 335.82 6716.4 95.22306238 4105.175016 832461.07


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T1-20/1 5.579 25.4 26.87 170.6245 46.81056241 668.2976162 1644.2627

20% B/T1-20/2 2.763 25.4 18.27 116.0145 29.26748971 843.6979693 2257.4471

B/T1-20/3 2.777 25.4 17.53 111.3155 29.08498269 834.2099091 2155.0927

Volume B/T1-30/1 4.705 25.4 22.68 144.018 30.09793669 443.7737212 1645.6722

30% B/T1-30/2 5.722 25.4 28.86 183.261 26.20634921 273.591341 1721.9018

B/T1-30/3 4.661 25.4 33.59 213.2965 34.73177285 471.3191769 2460.3156

Volume B/T1-40/1 2.977 25.4 81.2 515.62 46.04914934 723.1545517 9311.8743

40% B/T1-40/2 3.449 25.4 72.81 462.3435 42.31371943 586.3024007 7207.0536

B/T1-40/3 3.625 25.4 90.62 575.437 49.07289964 632.8809981 8534.4583

Volume B/T1-50/1 2.164 25.4 70.73 449.1355 54.68758942 1430.191215 11158.513

50% B/T1-50/2 1.71 25.4 38.32 243.332 29.4219018 948.7596425 7650.4909

B/T1-50/3 3.405 25.4 88.43 561.5305 72.348193 1202.466965 8866.3


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T2-20/1 4.281 30 110.79 830.925 90.80403246 1515.067115 14557.2

20% B/T2-20/2 4.237 30 92.56 694.2 74.07763105 1248.822129 12288.176

B/T2-20/3 2.244 30 118.08 885.6 91.96062737 2859.116632 29598.93

Volume B/T2-30/1 1.052 30 240.42 1803.15 108.6584043 5533.256602 128551.57

30% B/T2-30/2 1.512 30 308.59 2314.425 128.5443526 4474.531905 114802.83

B/T2-30/3 1.246 30 280.01 2100.075 124.1081278 5335.994947 126409.01

Volume B/T2-40/1 1.163 30 280.99 2107.425 133.2276185 6248.461742 135904.45

40% B/T2-40/2 1.563 30 189.77 1423.275 85.8714766 2996.736228 68295.345

B/T2-40/3 0.931 30 160.13 1200.975 79.07654321 4718.733931 96748.792

Volume B/T2-50/1 1.875 30 393.88 2954.1 119.6500537 2857.314714 118164

50% B/T2-50/2 1.508 30 349.33 2619.975 105.2365208 3034.151794 130303.8

B/T2-50/3 0.92 30 264.59 1984.425 80.68982343 3986.651355 161773.78


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T3-20/1 2.918 50 126.89 1586.125 68.26392083 3094.454818 113242.87

20% B/T3-20/2 3.79 50 112.36 1404.5 54.68101121 1878.60774 77204.266

B/T3-20/3 2.244 50 113.75 1421.875 70.76447406 4171.292409 132007.11

Volume B/T3-30/1 3.453 50 131.37 1642.125 39.33208018 1066.544756 99075.985

30% B/T3-30/2 3.065 50 126.46 1580.75 38.56789079 1219.314427 107446.3

B/T3-30/3 2.401 50 85.02 1062.75 30.89569161 1276.57175 92214.182

Volume B/T3-40/1 2.844 50 411.47 5143.375 195.1187513 8052.483085 376770.91

40% B/T3-40/2 2.94 50 218.27 2728.375 88.57641425 3392.796403 193337.23

B/T3-40/3 2.53 50 224.7 2808.75 86.08447798 3831.698802 231287.06

Volume B/T3-50/1 2.087 50 232.97 2912.125 65.61611041 2911.147953 290700.87

50% B/T3-50/2 1.788 50 191.9 2398.75 61.57746117 3416.596821 279496.41

B/T3-50/3 1.987 50 125.58 1569.75 33.84857001 1543.026503 164585.43


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T4-20/1 2.099 65 116.07 1886.1375 42.05372272 3206.378552 316378.07

20% B/T4-20/2 2.229 65 127.6 2073.5 53.18726537 3953.521691 327521.22

B/T4-20/3 4.263 65 175.63 2853.9875 70.5995671 2776.597178 235712.28

Volume B/T4-30/1 3.311 65 108.46 1762.475 37.69422156 1705.6629 187417.12

30% B/T4-30/2 3.447 65 246.52 4005.95 85.40621402 3792.851316 409175.58

B/T4-30/3 4.819 65 219.54 3567.525 76.6005758 2381.511664 260648.7

Volume B/T4-40/1 4.197 65 198.74 3229.525 51.09359473 1602.319694 270922.55

40% B/T4-40/2 4.188 65 206.2 3350.75 46.6801529 1440.139484 281696.09

B/T4-40/3 4.493 65 101.09 1642.7125 24.33330463 687.1430438 128727.29

Volume B/T4-50/1 2.486 65 291.09 4730.2125 80.45736454 4425.200087 669923.16

50% B/T4-50/2 3.021 65 351.39 5710.0875 98.65176547 4379.96153 665483.83

B/T4-50/3 4.542 65 210.13 3414.6125 65.58036527 2013.310628 264691.36


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T5-20/1 10.054 80 91.67 1833.4 26.94591417 529.4061779 97256.15

20% B/T5-20/2 11.793 80 139.05 2781 43.21314575 717.1727923 125769.52

B/T5-20/3 5.71 80 83.34 1666.8 21.86363267 735.9053403 155684.76

Volume B/T5-30/1 7.825 80 131.97 2639.4 44.53978801 1156.466933 179895.21

30% B/T5-30/2 11.947 80 182.6 3652 58.47784663 966.8686349 163031.17

B/T5-30/3 7.779 80 194.41 3888.2 67.71287075 1768.548097 266577.54

Volume B/T5-40/1 7.748 80 204.74 4094.8 53.91428428 1226.839022 281865.43

40% B/T5-40/2 6.27 80 229.99 4599.8 64.00463822 1944.39548 391264.22

B/T5-40/3 8.619 80 224.45 4489 63.6436673 1369.806413 277773.91

Volume B/T5-50/1 4.486 80 326.01 6520.2 60.54671449 2042.071381 775176.1

50% B/T5-50/2 6.104 80 442.98 8859.6 87.48782093 2184.055943 774102.23

B/T5-50/3 5.239 80 317.59 6351.8 62.67646401 1876.618095 646617.04


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T1-20/1 2.729 25.4 18.88 119.888 32.89108368 959.9686741 2361.8829

20% B/T1-20/2 5.525 25.4 17.74 112.649 28.41846018 409.6855767 1096.1784

B/T1-20/3 4.121 25.4 25.11 159.4485 41.66137566 805.217873 2080.1948

Volume B/T1-30/1 6.338 25.4 54.87 348.4245 72.81630449 797.0047029 2955.5794

30% B/T1-30/2 4.446 25.4 31.45 199.7075 28.55820106 383.7117216 2414.9665

B/T1-30/3 5.834 25.4 46.45 294.9575 48.02890291 520.7190943 2718.1862

Volume B/T1-40/1 4.212 25.4 67.18 426.593 38.09829868 422.8687252 5445.1713

40% B/T1-40/2 2.384 25.4 53.56 340.106 31.12653225 623.9620167 7669.98

B/T1-40/3 3.33 25.4 61.6 391.16 33.35787484 468.3197661 6315.335

Volume B/T1-50/1 2.544 25.4 115.19 731.4565 89.06352927 1981.27781 15458.152

50% B/T1-50/2 2.024 25.4 103.78 659.003 79.68175807 2170.850775 17505.039

B/T1-50/3 1.738 25.4 79.87 507.1745 65.34490756 2127.769394 15688.948


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T2-20/1 2.143 30 74.04 555.3 60.68355053 2022.650174 19434.204

20% B/T2-20/2 3.155 30 92.38 692.85 73.93357343 1673.841373 16470.285

B/T2-20/3 1.765 30 63.64 477.3 49.5627907 1959.132645 20281.87

Volume B/T2-30/1 3.37 30 133.35 1000.125 60.26785714 958.0519893 22257.975

30% B/T2-30/2 1.698 30 102.9 771.75 42.86339116 1328.603037 34087.898

B/T2-30/3 0.815 30 38.2 286.5 16.93128989 1112.924401 26365.031

Volume B/T2-40/1 1.742 30 192.18 1441.35 91.11955484 2853.132914 62055.827

40% B/T2-40/2 1.441 30 248.15 1861.125 112.2885963 4250.404251 96866.325

B/T2-40/3 1.334 30 131.2 984 64.79012346 2698.239358 55322.339

Volume B/T2-50/1 1.924 30 235.52 1766.4 71.54458373 1665.014981 68856.549

50% B/T2-50/2 2.676 30 340.86 2556.45 102.6849125 1668.371231 71649.383

B/T2-50/3 1.972 30 225.25 1689.375 68.69262908 1583.3632 64251.078


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T3-20/1 1.837 50 38.56 482 20.74439899 1493.722439 54663.4

20% B/T3-20/2 1.731 50 7.21 90.125 3.508811773 263.9379162 10846.933

B/T3-20/3 1.774 50 92.92 1161.5 57.80602136 4310.202436 136403.14

Volume B/T3-30/1 2.172 50 130.45 1630.625 39.05663287 1683.696177 156405.87

30% B/T3-30/2 1.194 50 50.61 632.625 15.43508582 1252.636391 110382.64

B/T3-30/3 3.524 50 120.78 1509.75 43.89063318 1235.592929 89254.044

Volume B/T3-40/1 4.77 50 180.02 2250.25 85.36534283 2100.504494 98281.359

40% B/T3-40/2 2.242 50 131.05 1638.125 53.18155994 2671.23747 152219.47

B/T3-40/3 2.881 50 317.77 3972.125 121.7403853 4758.591754 287235.7

Volume B/T3-50/1 1.91 50 286.38 3579.75 80.6590621 3910.173653 390461.39

50% B/T3-50/2 1.959 50 503.47 6293.375 161.5549994 8181.358694 669280.14

B/T3-50/3 1.341 50 237.87 2973.375 64.11498128 4330.735585 461933.72


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T4-20/1 3.019 65 139.2 2262 50.43403294 2673.519593 263800.1

20% B/T4-20/2 4.228 65 111.1 1805.375 46.30960174 1814.774216 150341.17

B/T4-20/3 3.539 65 98.52 1600.95 39.60296846 1876.175022 159273.19

Volume B/T4-30/1 6.815 65 170.63 2772.7375 59.30080237 1303.683937 143247.93

30% B/T4-30/2 7.163 65 200.15 3252.4375 69.3414479 1481.888698 159867.24

B/T4-30/3 4.157 65 137.99 2242.3375 48.1466405 1735.256059 189918.13

Volume B/T4-40/1 4.483 65 257.33 4181.6125 66.15635872 1942.336786 328413.13

40% B/T4-40/2 3.609 65 203.27 3303.1375 46.01685101 1647.437603 322244.3

B/T4-40/3 5.257 65 226.83 3685.9875 54.60009388 1317.764769 246866.04

Volume B/T4-50/1 5.16 65 319.87 5197.8875 88.4121653 2342.774883 354668.52

50% B/T4-50/2 4.643 65 340.38 5531.175 95.56073858 2760.558619 419434.53

B/T4-50/3 3.064 65 254.8 4140.5 79.52161553 3618.932796 475783.63


Jenis No Spesimen


Beban Momen Bending


Kekakuan


Volume B/T5-20/1 3.771 80 126.92 2538.4 37.3074662 1954.223293 359006.45

20% B/T5-20/2 4.359 80 84 1680 26.10502871 1172.113121 205551.73

B/T5-20/3 5.271 80 119.54 2390.8 31.36043496 1143.470071 241907.29

Volume B/T5-30/1 6.094 80 161.59 3231.8 54.53651848 1818.253282 282839.95

30% B/T5-30/2 8.7 80 202.57 4051.4 64.87326064 1472.927728 248361.69

B/T5-30/3 8.717 80 186.63 3732.6 65.00310204 1515.083109 228372.15

Volume B/T5-40/1 5.937 80 345.83 6916.6 91.06758295 2704.394911 621332.88

40% B/T5-40/2 5.277 80 306.08 6121.6 85.17996289 3074.617176 618694.97

B/T5-40/3 3.928 80 186.16 3723.2 52.78638941 2492.937308 505526.14

Volume B/T5-50/1 4.256 80 180.42 3608.4 33.50767838 1191.193529 452180.45

50% B/T5-50/2 5.522 80 226.56 4531.2 44.74522712 1234.755582 437638.54

B/T5-50/3 5.776 80 282.5 5650 55.75144395 1514.079733 521698.98

LAMPIRAN IV

Tabel 4.1. Sifat mekanik dari beberapa jenis serat.( Dieter H. Mueller )

Cotton Flax Jute Kenaf E-Glass Ramie Sisal

Diameter m - 11–33 200 200 5–25 40–80 50–200

Length mm 10–60 10–40 1–5 2–6 - 60–260 1–5

Tensile strength MPa 330–585

345–1035

393–773

930 1800 400–1050

511–635

Young’s modulus GPa 4.5–12.6

27.6–45.0

26.5 53.0 69.0–73.0

61.5 9.4–15.8

Density g/cm3

1.5–1.54

1.43–1.52

1.44–1.50

1.5 2.5 1.5–1.6 1.16–

1.5

Maximum strain % 7.0–8.0 2.7–3.2 1.5–1.8

1.6 2.5–3.0 3.6–3.8 2.0–2.5

Specific tensile strength

km 39.2 73.8 52.5 63.2 73.4 71.4 43.2

Specific stiffness km 0.85 3.21 1.80 3.60 2.98 4.18 1.07

Tabel 4.2. Sifat mekanik dari beberapa jenis material polymers

(Smith, W.F., Hashemi, J., 2006).

Type Density (gr/cm

3)

Ultimate Tensile

Strength (MPa)

Yield Strength

(MPa)

Modulus of

Elasticity (GPa)

% Elongation

at break

Izod Impact

Strength (J)

Epoxy 1.2 70 60 2.25 5 0.3

Phenolic 1.705 56 52 7 1.3 0.18

Polybutylene terepthalate (PBT) 1.355 55 67 12 148 0.27

Nylon 66 1.095 62 63 2.1 152 7

Polyester 1.65 58 70 3.5 2.4 0.22

Polyethylene 0.925 16 16 0.25 350 1.068

Polypropylene (PP) 1.07 50 28 2.25 427 0.16

Polyvinyl Chloride (PVC) 1.305 47 38 3.1 62 5.3

Polymethyl Metharcrylate (PMMA) 1.17 62 69 2.9 15 0.16

LAMPIRAN V

UJI DENSITY SERAT

Tabel 6.1. ASTM D 3800-79.

Tabel 6.2. Hasil Uji Density Serat Kenaf Dengan Kadar Air 10%

(ASTM D 3800 - 79).

ASTM D 3800-79

ρs1 = ( Mu x ρm ) / ( Mu – Mm ) …….....….[1]

ρs2 = (ρs1 – (ρa x wa)) / ws ………………… [2]

ws = (Mu – ρa) / Mu …………………….......[3] ρs1 = massa jenis serat ρs2 = massa jenis serat (kadar air : 0%) ρa = massa jenis udara = 0.08298 gr/cm3

m = massa jenis air = 0.997 Mu = massa serat di udara Mm = massa serat dalam air ws = berat serat, gr

wa = berat udara, gr

Specimen serat

Massa di dalam air Ma

(gr)

Massa di udara Mu

(gr)

Massa jenis air ρu (gr/cm3)

Massa jenis serat ρs

(gr/cm3)

1 30.616 82.324 0.997 1.587

2 30.599 83.654 0.997 1.572

3 30.529 80.645 0.997 1.592

4 30.536 84.398 0.997 1.562

Jumlah total 6.314

Massa jenis serat rata-rata 1.578

Grafik 6.1. Hasil Uji Density Serat Ramie.

Massa jenis

Massa jenis/densitas suatu material merupakan. perbandingan

antara berat dan volume dari material tersebut. Dalam menentukan massa

jenis suatu benda yang bentuknya beraturan dapat mudah kita lakukan

dengan menggunakan persamaan 2.1 ( Tipler, 1991).

ρ = V

gmu ⇒ ρ = V

Wu …………………………………. (2.1)

ρ = massa jenis, gram/cm3 uW = berat di udara, gram

um = massa udara,gram V = volume material, cm3

g = grafitasi,gram/second2 = 9,8 gr/sec2

Untuk benda dengan bentuk yang tidak beraturan, dimana kita

kesulitan untuk menentukan volumenya. Kita dapat menghitung massa

jenis dengan hukum Archimedes,bahwa berat benda di dalam air sama

dengan berat di udara dikurangi dengan gaya ke atas yang diberikan

oleh air. Gaya tekan ke atas merupakan volume dari benda tersebut.

1,587317784

1,572010894

1,592457645

1,562229512

1,578503959

1,5451,55

1,5551,56

1,5651,57

1,5751,58

1,5851,59

1,595

1 2 3 4 Rata-rata

De

nsi

ty (

gr/c

m2 )

Spesimen serat

Density Serat Ramie

Dengan massa jenis air murni ( ρ air) 0,997 gr/cm3 pada suhu 23ºC maka

volume benda dapat kita hitung dengan persamaan 2.2 dan 2.3 sebagai

berikut (Tipler,1991):

Cara I : V = air

au WW

)-(.........................................(2.2)

ρ = V

Wu ⇒ = au

airu

WW

W

-

..................................(2.3)

aW = berat di air, gram uW = berat di udara, gram

air = 0,997 gr/cm3 V = volume material, cm3

Cara II : Dengan Gelas Ukur V = V1 – V2

V= volume benda, cm3

V1= volume benda + volume air

V2= volume air/water

LAMPIRAN VI

Analisa perhitungan fraksi volume serat ramie

Diketahui :

Massa jenis serat (ρf) = 1.578 gr/cm3

Massa jenis matrik Polyester (ρm) = 1.65 gr/cm3

Specimen dengan Vf 20% tebal 1mm

Volume composit (Vc) = 18.75 cm3

Volume serat (Vf) = 20% x Vc

= 0.2 x 18.75 cm3

= 3.75 cm3

Berat serat (Wf) = ρf x Vf

= 1.578 gr/cm3 x 3.75 cm3

= 5.92 gr

Volume matrik (Vm) = 80% x Vc

= 0.8 x 18.75 cm3

= 15 cm3

Berat matrik (Wm) = ρm x Vm

=1.65 gr/cm3 x 15 cm3

= 24.75 gr

Berat composit (Wc) = Wf + Wm

= 5.92 gr + 24.75 gr

= 30.42 gr

Checking fraksi volume (Vf)

%100//

/x

WW

WV

mmff

ff

f

𝑉𝑓 =5.92 1.578

(5.92 1.578) + (24,75 1.65) × 100%

𝑉𝑓 =3.75158

18.75158× 100%

𝑉𝑓 = 0.2 × 100%

𝑉𝑓 = 20%

Tabel perhitungan fraksi volume komposit serat ramie

Perhitungan Fraksi Volume Serat Ramie

20% 30%

1mm 2mm 3mm 4mm 5mm 1mm 2mm 3mm 4mm 5mm

Volume composit Vc (cm3) 18.75 37.50 56.25 75 93.75 18.75 37.50 56.25 75 93.75

Volume serat Vf (cm3) 3.75 7.5 11.25 15 18.75 5.625 11.25 16.875 22.5 28.125

Volume matrik Vm (cm3) 15 30 45 60 75 13.125 26.25 39.375 52.5 65.625

Berat serat Wf (gr) 5.92 11.835 17.7525 23.67 29.5875 8.87625 17.7525 26.62875 35.505 44.38125

Berat matrik Wm (gr) 24,75 39 58.5 78 97.5 17.0625 34.125 51.1875 68.25 85.3125

Berat composit Wc (gr) 30,42 50,84 76,25 101,67 127,09 25,936 51,878 77,82 103,755 129,69

Perhitungan Fraksi Volume Serat Ramie

40% 50% 1mm 2mm 3mm 4mm 5mm 1mm 2mm 3mm 4mm 5mm

Volume composit Vc (cm3) 18.75 37.50 56.25 75 93.75 18.75 37.50 56.25 75 93.75

Volume serat Vf (cm3) 7.5 15 22.5 30 37.5 9.375 18.75 28.125 37.5 46.875

Volume matrik Vm (cm3) 11.25 22.5 33.75 45 56.25 9.375 18.75 28.125 37.5 46.875

Berat serat Wf (gr) 11.835 23.67 35.505 47.34 59.175 14.7938 29.588 44.3813 59.175 73.9688

Berat matrik Wm (gr) 14.625 29.25 43.875 58.5 73.125 12.1875 24.375 36.5625 48.75 60.9375

Berat composit Wc (gr) 26,46 52,92 79,38 105,84 132,3 26,98 53,963 80,94 107,93 134,91

LAMPIRAN VII

Konversi Satuan

LAMPIRAN VIII

Gambar Spesimen

Gambar hasil cetakan komposit serat Ramie dengan matrik polyester

untuk pengujian bending dan impact

Gambar specimen uji bending komposit serat ramie sebelum pengujian.

Gambar specimen uji impact komposit serat ramie sebelum pengujian.

Gambar specimen uji bending komposit serat ramie setelah pengujian.

Gambar specimen uji impact komposit serat ramie setelah pengujian.

Gambar specimen uji tarik komposit serat ramie sebelum pengujian.

Gambar ramie jenis pujon

Gambar mesin pengolahan ramie

Mesin pemisah serat ramie dengan batangnya

Proses Dekortikasi: Proses pemisahan serat dari batang tanaman,

hasilnya serat kasar disebut “China Grass “.

Mesin pemisah ramie

Mesin pembersih ramie

Proses Degumisasi: Proses pembersihan serat dari getah pectin, legnin

wales dan lain-lain, hasilnya serat degum disebut “ Degummed Fiber “.

Mesin pelembut serat ramie

Proses Softening: Proses pelepasan dan proses penghalusan baik

secara kimiawi maupun mekanis agar serat rami tersebut dapat diproses

untuk dijadikan seperti kapas.

Mesin pemotong serat ramie dan membukanya

Proses Cutting dan Opening: Proses mekanisisasi untuk memotong

serat dan membukanya agar serat tersebut menjadi serat individual untuk

serat panjang disebut “Top Rami” dan untuk serat pendek disebut “Staple

Fiber “.

Beberapa benang hasil pengolahan serat ramie

Serat ramie yang telah diproses sampai menyerupai serat kapas sudah

dapat dipintal menjadi benang untuk ditenun menjadi tekstil dari ramie

peringkat No.2 setelah sutera, (cotton nomor 7).