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FLEXURAL TEST OF UNTREATED ELAIS GUINEESIS POLYMER COMPOSITES
Saiful Adli Bin Yaman
'fA Bachelor of Engineering with Honours 455 (Mechanical Engineering and Manufacturing Systems) 5132
20062006
UNIVERSITI MALAYSIA SARA W AK
RI3a BORANG PENGESAHAN STATUS TESIS
Judul: FLEXURAL TEST OF UNTREATED ELAIS GUlNEESlS POLYMER COMPOSITES
SESI PENGAJIAN : 2005/2006
Saya SAIFUL ADLI BIN YAMAN
(HURUF BESAR)
mengaku membenarkan tesis* ini disimpan di Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dengan syarat-syarat kegunaan seperti berikut:
I. Tesis adalah hakmilik Universiti Malaysia Sarawak. 2. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat salinan untuk tujuan
pengajian sahaja. 3. Membuat pendigitan untuk membangunkan Pangkalan Data Kandungan Tempatan. 4. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat salinan tesis ini
sebagai bahan pertukaran antara institusi pengajian tinggi. 5. ** Sila tandakan ( '" ) di kotak yang berkenaan.
D SULIT (Mengandungi maklumat yang berdarjah keselamatari atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972).
D TERHAD (Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasilbadan di mana penyelidikan dijalankan).
TIDAK TERHAD
(TANDATANGAN PENULlS)
Alamat tetap : NO.86 TAMAN SRI SENA 2 JALAN SEMARIANG 93050 KUCHING SARAW AK PUAN MAHSHURI YUSOF
Nama Penyelia
~ C_C___Tarikh : __.J_c _1_1_?---'-'O_-b_ _____ Tarikh : _t-(----,b{_'
Catatan * Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah, Sarjana dan Sarjana Muda. ** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasalorganisasi
berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai SULIT dan TERHAD.
This Final Year Project attached here:
: Flexural Test of Untreated Elais Guineesis Polymer Composites Title
Author's Name : Saiful Adli Bin Yaman
Matric Number : 9191
Has been read and approved by:
Date
Project Supervisor
P.I<HIDMAT MAI<LUMAT AI<ADEMII< UNIMAS
1/111111 "IIIIII" 1111111111 1000165780
FLEXURAL TEST OF UNTREATED ELAIS GUINEESIS
POLYMER COMPOSITES
SAIFUL ADLI BIN YAM AN
This project is submitted in partial fulfillment of the requirements for the degree of Bachelor of Engineering with Honours
(Mechanical Eo.gineering & Manufacturing System}
Faculty of Engineering UNIVERSITI MALAYSIA SARA W AK
2006
To my family
ACKNOWLEDGEMENT
I would like to express my gratitude to my supervisor, Madam Mahshuri Bt. Yusof for
her guidance and advice to accomplish this final year project. Your support and kindness
is greatly appreciated. I would like to thank to the mechanical laboratory technicians for
their cooperation and valuable support. I also would like to thanks the Timber Research
Laboratory for their environment and facilities. All your cooperation is highly
appreciated. Last but not least, a special thanks to my family for their continuous moral
support. Finally, thanks to my entire friend who have given advices and suggestions on
completing this report. Thanks everyone.
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!
ABSTRACT
The empty fruit bunch (EFB) fibre, natural fibre was combined with unsaturated
polyester resin matrix, to produce advance structural composite. The composites were
fabricated using random lamination with different fibre volume fraction of 40%, 50%,
and 60%. An experimental investigation has been carried out to measure the behavior of
empty fruit bunch (EFB) reinforced unsaturated polyester composites when subjected to
flexure or three-point loading. A number of tests were carried out and the result was
obtained according to the load deflections data. The largest fibre volume fraction
demonstrates a high flexural stress and flexural modulus value.
III
ABSTRAK
Gentian yang diperolehi daripada hampas kelapa sawit teJah diperkukuhkan dengan resin
poliester yang tidak tepu untuk menghasilkan komposit gentian semulajadi. Komposit ini
telah dibuat dengan menggunakan campuran gentian secara ram bang, pada berIainan
pecahan isipadu gentian, iaitu 40%, 50%, dan 60%. Eksperimen telahpun dijalankan bagi
rnenentukan sifat-sifat komposit gentian kelapa sawit bersama poliester tidak tepu ini
berdasarkan kepada ujian pelenturan atau ujian pada bebanan tiga titik. Sebilangan
eksperimen telah dijalankan dan hasil eksperimen yang diperolehi adalah berdasarkan
kepada data daya pemesongan. Pecahan isipadu gentian yang paling besar menunjukkan
nilai tekanan dan modulus pelenturan yang paling tinggi.
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Pusat Kbidmat MakJumal ~ademl UNlVERSJTI MALAYSlA SARAWAK.
LIST OF CONTENTS
CONTENTS
DEDICATION
ACKNOWLEDMENTS
ABSTRACT
LIST OF CONTENT
LIST OF TABLE
LIST OF FIGURE
NOMENCLATURE
CBAPTERONE
INTRODUCTION
1.1 Introduction
1.2 Scope and Objective
PAGE
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iii
v
IX
XI
Xlll
2
v
CHAPTER TWO
LITERATURE REVIEW
2.1 Natural Fibres
2.2 Polymers Matrix Composite
2.2.1 Thermosets
2.2.2 Unsaturated Polyester Resins
2.3 Flexural Testing
2.3.1 Flexural Test Usages and Advantages
2.3.2 Testing Configuration (ASTM 0790)
2.3.3 Flexural Properties
2.3.3.1 Stress-Strain Behavior
2.3.3.2 Flexural Strength
2.3.3.3 Flexural Modulus
2.3.3.4 Failure Modes
CHAPTER THREE
METHODOLOGY
3.1
3.2
3.3
Introduction
Fibre Extraction
Fibre Volume Fraction
3
4
5
6
8
9
10
12
13
18
22
25
27
27
29
VI
l r
3.4 Composite Specimen Production
3.5 Specimen Dimension and Testing Configuration (ASTM 0790)
CHAPTER FOUR
RESULT AND DISCUSSION
4.1 Introduction
4.2 Loads at Break and Deflection
4.3 Deflection at Break
4.4 Loads, deflection, and Strain at Yield
4.5 Stresses at Break
4.6 Stress-Strain
4.7 Flexural Properties
4.8 Flexure Failure
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
5.1 Conclusion
5.2 Recommendation
VII
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29
31
36
37
38
39
41
42
44
45
47
49
51
54
REFERENCES
APPENDICES
viii
LIST OF TABLE
Table Page
2.1 Relative Proportions of the Major Constituents and 4
Properties of Some the Common Natural Fibres
3.1 Possibilities for Dimensional, Support & Loading 32
Nose Radii, Span-to-Thickness Ratios & Loading
Rate for Flexure Specimens in Several Specifications
3.2 Dimensions and Testing Configuration of Random Orientation 33
for Flexure Test as specified by ASTM 0790
4.1 Result Summaries of Load, Deflection, and Strain at Yield 40
5. J Flexural Properties of 40%,50%, and 60% Fibre Volume Fraction 48
5.2 Mechanical Properties of 40%,50%, and 60% Fibre Volume Fraction . 48
Al Collected Experimental Data and Stress Value for 40% Fibre 54
Volume Fraction
A2 Collected Experimental Data and Stress Value for 50% Fibre 55
Volume Fraction
A3 Collected Experimental Data and Stress Value for 60% Fibre 55
Volume Fraction
BI Collected Experimental Data and Modulus Value for 40% Fibre 56
Volume Fraction
IX
82 Collected Experimental Data and Stress Value for 50% Fibre 57
Volume Fraction
83 Collected Experimental Data and Stress Value for 60% Fibre 57
Volume Fraction
x
LIST OF FIGURE
Figure Page
2.1 Three-Point Flexure Loading Configuration to
2.2 Normal Stress «(J'xx) Distribution in Various Layers of 13
(a) [90/0/ (90)60/90] and (b) [0°/90°/ (0°) J900/0 0]
2.3 Variation in Normal Stress and Shear Stress in a Flexure Test 14
2.4 Stress in a Beam Subjected To Three-Point Flexure 16
2.5 Three-Point Flexure Test Shear Force and Bending Moment 17
Diagrams
2.6 Flexural Stress-Strain Response of [Oh2 CarbonlEpoxy Test 20
Specimen
2.7 Face Involved in Bending a Simple Beam 21
2.8 Load Deflection Diagrams for Various 0° Unidirectional 24 ~.
Laminates in Three-Point Flexure Tests
2.9 Schematic of Possible Failure Modes in Three-Point Flexure 26
Tests
3.1 The Empty Fruit Bunch (EFB) Fibres 28
3.2 The Composite Specimen Surface after the Hot Pressing and 30
Hot Curing
3.3 The Test Specimen Cut from Composite Board 31
xi
3.4 Schematic Diagram of Rectangular Test Specimen 33
Dimension as Described in ASTM 0790
3.5 Testometric Machine 34
3.6 The Three point Bending Heads with The Adjustable Span 34
for Flexure Test
4.1 Load Deflection Curves of 40%, 50%, and 60% EFB 37
Reinforced Unsaturated Polyester Composite
4.2 Stress Break of Random Laminated EFB Unsaturated 40
Polye ter Composite
4.3 Stress-Strain Curves of 40%, 50%, and 60% EFB-Reinforced 42
Unsaturated Polyester Composite
4.4 Flexural Stress and Flexural Modulus of Random Laminated 43
EFB Composites
4.5 The Flexure Failure of Random EFB-Reinforced Unsaturated 46
Polyester Composite
xii
NOMENCLATURE
b pecimen width
D Deflection of the beam
Er Flexural modulus
Fs Shear force
h Thickness
L Span length
m Initial slope
M Bending moment
N Newton
p ForcelLoad
pr Fibre density
Pm Fibre matrix
Vr Fibre volume fraction .....
Wr Fibre weight
Wm Matrix weight
0 Centre deflection
t Shear stress
(J Normal stress
xiii
CHAPTER!
INTRODUCTION
1.1 Introduction
There are various kinds of natural fibres that suitable and easily can be found,
such as wool, silk, cotton, hemp, jute, sisal, and flax. All these fibres are in fact comes
from animal or plant product, which are widely used for textiles, twine, rope and clothes
nowadays.
The natural fibres from the local plant will be extracted and used in this study.
The oil palm crop waste is the type of plant that has been identified as a potential fibre for
particle reinforced composite. ··Oil palm, or its scientific name Elais guineensis, is
originated from West Africa and introduced to Malaysia in 1987 as an ornamental plant
(Gurmit et. all 1999). The oil palm empty fibre bunch (EFB) is the one of the fibre
sources from the oil palm crops that will be used in this study. These empty fruit bunches
are obtained at first stages of the milling process and the strand from the empty fruit
bunches are preferred because it can be obtained during regular harvest and oil palm
processing.
According to Sirim Berhad Malaysia, the empty fruit fibres (EFB) was identified
as the first series of standards on oil palm fibres because the EFB has the highest fibre
yields and is the only material commercially utilised for fibre extraction. Compare with
the other fibres from other wood species, the EFB fibres are characteristically compatible,
clean and biodegradable. These EFB fibres are suitable for the manufacture of mattress,
insulation, particleboard, car seat, and composite panel product.
1.2 Scopes and Objective
Objectively, the flexural test is a test method for measuring behaviour of materials
that subjected to three-point loading. To perform the flexural test in this study, the
untreated Elais guineensis were used as a materials test specimen. The fibres from Elais
guineensis or specifically known as oil palm empty fruit bunch (EFB) are extracted
through a few processes before performing the flexural test without treated them with
chemical solution. To achieve the objective mentioned before, ASTM D790-00 will be
utilized to obtain the data regarding to flexural test properties of these natural fibres
reinforced polymer composites.
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CHAPTER 2
LITERATURE REVIEW
2.1 Natural Fibres
According to Ghosh (2004), the natural fibres are basically classified into three
groups of their origin: vegetable origin, animal or insect origin, and mineral origin.
Among these, natural fibres are important in terms of production volume, industrial
activity, and usage patterns. The fibres that were used in this study were the natural fibres
ofthe local plant; oil palm empty fruit bunch (EFB) fibres.
The EFB fibres that were used in this study are the natural structure made of
cellulose fibres. The strands ofcellulose fibres in different plants are associated with
different amounts of other natural substances such as hemicelluloses, lignin, pectinous
matter, waxes, and gums (Ghosh, 2004). According to Matthew and Rawlings (1999),
the fibres extracted from plants are essentially micro-composites consisting of cellulose
fibres in an amorphous matrix of lignin and hemicelluloses and often have a high length
to diameter ratio, called the aspect ratio, of greater than 1000. Table 2.1 shows the
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relative proportion of the major constituents and properties of some of the common
natural fibres.
Table 2.1: Relative Proportions of the Major Constituents and Properties of Some
Common Natural Fibres (Matthew and Rawlings, 1999)
Density Cellulose Hemicellulose Lignin Young's Tensile Specific Specific
(Mglm3) (%) (%) (%) Modulus Strength Modulus Strength
(GPa) (MPa) [(GPa)/ [(MPa)/
I (Mg/m3)] (Mglm3)]
Wood 1.5 40 40 20 - 500 - 333
Jute 1.3 72 14 14 55.5 442 43 340
Hemp - 71 22 7 - 460 - -I I
Sisal 0.7 74 - 26 17 530 'I
24 757
2.2 Polymers Matrix Composites
Polymers are the most common matrix materials for composites and classified
into three classes, which are thermoplastic, thermosets and rubbers (Matthew and
Rawlings, 1999). lrfan (1998) defined polymer as a macromolecule formed by the
chemical combination of identical units called monomers. The process by which
polymers are formed is known as polymerization, which occurs via addition reaction or
condensation reaction. According to Matthew and Rawlings (1999), the mechanical
properties of polymers are generally inadequate for many structural purposes. The
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strength and stiffness of polymers are lower than metals and ceramics. This means there
is B considerable benefit to be gained by reinforcing polymers and the reinforcement
without having exceptional properties.
%.2.1 Thermosets
In this study, only the thermosets polymer will be adopted. McGrum et. al. (1997)
mentioned that thermosets polymers are those whose precursors are heated to an
appropriate temperature for a short time, so that they will flow as a viscous liquid with
the reaction of chemical cross-linking then causes the liquid to solidifY to form an
infusible mass. The used of thermosets polymer as matrices in reinforced plastics have
some reason such as low viscosity at the precursors liquids that prior to cross-linking.
Economical forming is possible for large component and the high softening points can be
achieved in materials of only moderate cost. According to Matthew and Rawlings (1999),
thennosetting polymers or thermosets are resins, which readily cross-link during curing.
Furthermore, the application of heat and pressure or the additions of a curing agent or
hardener are involved in the curing,process.
Harper (2000) has defined reSInS as any class of solid, semi solid, or liquid
organic material, generally the product of natural or synthetic origin with a high
molecular weight and with no melting point. By gluing bundles of fibres together with
resin matrices, materials are made were strong, stiff fibres are able to carry most of the
stress whilst the matrix distributes the external load to all fibres as well as affording
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According
protection and preventing fibre buckling under compressive forces (Hollaway, 1994).
to Harper (2000), the important beneficial factor lies in the inherent
enhancement of thermoset resins is in their physical, electrical, thermal, and chemical
properties when they are exposed to severe environmental conditions. There is various
kind of thermosets resin such as epoxies, polyester, phenolics, polyurethanes, polyimides,
bismaleimides and vinyl ester. Only the unsaturated polyester resin will be used for fibre
reinforcement polymer in this study.
2.2.2 Unsaturated Polyester Resins
Historically, the first polyester product produced by reacting tartaric acid with
glycerol in 1847 and then prepared with well-defined polymeric structure in 1920. The
commercial application of unsaturated polyester was made in 1941 and like many other
fields of research and development, the development of polyester accelerated during and
after the Second World War (Irfan, 1998). The thermosets polyester has been the most
popular family of polymers for many years. This polyester is versatile, inexpensive, used
extensively with glass fibre rejpforcement and often in substantial plastic component
(McGrum et. al 1997).
According to McGrum et. al (1997), thermosetting polyester is derived from the
condensation effects of combining an unsaturated maleic anhydride or fumaric acid with
a polyhdric alcohol. When utilised as a molding compound, this unsaturated polyester
resin is dissolved in a cross linking monomer such as styrene with the addition of an
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inhibitor such as phenolic derivatives to prevent cross linking until the compound is
ready for use in the molding process. The compounds are further enhanced with additives
and use the free radical addition to polymerize the resin. The catalyst such as benzoyl
pen> ide and methylethyl ketone peroxide becomes the source for the free radical and
with elevated temperature the heat decomposes the peroxide, producing free radicals.
Irfan (1998) has stated that the cross linking of unsaturated polyester occurs via
free radical polymerisation, after addition of vinyl monomer such styrene and catalyst.
The catalyst is added in concentrations of 0.5%-2.0% to initiate formation of free
radicals, the amount depending on the temperature and the type of catalyst. In order to
obtain a high quality product, it is desirable that the styrene and fumerate radicals react
either alternately or in the proportion existing before cross-linking occurs. In
commercially available unsaturated polyester, 30% styrene or vinyl monomer is present.
The curing reaction converts the viscous resin to a hard thermoset within a few hours. In
the absence accelerator, oxygen in the air has an inhibiting effect on the curing process,
resulting in a softer surface on the product, despite the hardening of the inner portion.
The use of accelerator such as cobalt naphthenate eliminates such an effect.
Hollaway (1994) stated that the polyester resins are cured via a free radical co
polymerisation reaction, which can be initiated at room temperature with the organic
peroxides, by heat or radiation, such as ultra violet and visible light. It is able to cold-cure
polyester resins from liquid that makes them more suitable than any other resin system
for the manufacture of very large structures. The catalyst system consists of organic
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