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Optimal Performance Characteristics and Reinforcement Combinations

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Journal of Scientific Research & Reports
9(3): 1-10, 2016; Article no.JSRR.20385
ISSN: 2320-0227
SCIENCEDOMAIN international
www.sciencedomain.org
Optimal Performance Characteristics and
Reinforcement Combinations of Coconut Fibre
Reinforced High Density Polyethylene (HDPE)
Polymer Matrixes
Christopher Chukwutoo Ihueze1, Maduabuchi Kingsley Achike2*
and C. E. Okafor3
1
Department of Industrial/Production Engineering, Nnamdi Azikiwe University, Awka, Nigeria.
2
Federal College of Education (Technical), Umunze, Nigeria.
3
Department of Mechanical Engineering, Nnamdi Azikiwe University, Awka, Nigeria.
Authors’ contributions
This work was carried out in collaboration between all authors. Author MKA designed the study, wrote
the protocol and wrote the first draft of the manuscript. Author CCI plotted the graphs and author CEO
read proof the work and made useful corrections. All authors read and approved the final manuscript.
Article Information
DOI: 10.9734/JSRR/2016/20385
Editor(s):
(1) Mohamed Abd El-Moneim Ramadan, Pretreatment & Finishing of Cellulosic Fibres Department, Textile Research Division,
Egypt.
Reviewers:
(1) Randa M.Osman, National Research Centre, Cairo, Egypt.
(2) Danupon Tonnayopas, Prince of Songkla University, Thailand.
(3) Diene Ndiaye, University of Gaston Berger of Saint Louis, Senegal.
Complete Peer review History: http://sciencedomain.org/review-history/11904
th
Original Research Article
Received 25 July 2015
th
Accepted 6 September 2015
Published 19th October 2015
ABSTRACT
This paper investigated the performance of coconut fibre particles as a filler material and highdensity polyethylene as matrix in polymer matrix composites (PMC). Three different particle sizes
of the filler material were used in formulating the composite samples and the concentration of the
filler material varied up to 40% by volume. The composite samples were prepared by injection
moulding and kept at room temperature for 48 hours prior to testing in order to promote relaxation
of stresses. The test specimens were prepared and tested in accordance with ASTM standards
D638, D790, D256, and D785 for tensile strength, elastic modulus, flexural strength, impact
strength and Rockwell hardness respectively. At optimum condition of volume fractions and particle
sizes of coconut fibre-filler, the coconut fibre reinforced HDPE (CFRP) has 28.6 MPa, 800 MPa,
_____________________________________________________________________________________________________
*Corresponding author: Email: [email protected];
Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
22.3 MPa, 55.0 J/m and 54.0 HR as optimum value for tensile strength, elastic modulus, flexural
strength, impact strength and hardness. It can be concluded from the results obtained that the
Coconut fibre reinforced HDPE showed improved performance for applications of HDPE.
Keywords: Reinforcement combinations; coconut fibre; volume fraction; particle size; archimedes
principle; optimum performance.
of natural fibres for their use in composite
materials such as acetylation, alkali and
isocyanates treatments. These Treatments make
the fibres more hydrophobic. It is important to
indicate that the good cohesion between fibres
and matrix is governed by many parameters
such as the surface area, the roughness and the
surface tensile of fibres.
1. INTRODUCTION
Most of the pressing scientific problems that are
currently faced today are due to the limitations of
the materials that are currently available [1].
Mulinari [2] defined composite materials as
materials made from two or more constituent
materials with significantly different physical or
chemical properties, that when combined,
produce a material with characteristics different
from the individual components. The individual
components remain separate and distinct within
the finished structure. The fact that composites in
general can be custom tailored to suit individual
requirements, have desirable properties in
corrosive environment, provide higher strength to
weight ratio and have lower life-cycle costs has
aided in their evolution [3]. Binshan, Alrik and
Bank [4] observed that these qualities in addition
to the ability to monitor the performance of the
material in the field via embedded sensors give
composites an edge over conventional materials.
The ability of composites to withstand tensile,
compressive and impact loads without failure is a
measure of their reliability [5].
2. METHODOLOGY
The methodology of this research employs
experimental and analytical methods to
investigate tensile strength, elastic modulus,
flexural strength, impact strength and hardness
value of coconut fibre particles reinforced highdensity polyethylene composite at different
volume fractions and particle sizes.
The researchers considered fibre surface
treatment, volume fraction of fibres, and particle
size of fibres as factors controlling the behavior
or characteristics of HDPE matrix filled fillers.
The ASTM specified standard particle sizes are
presented in Table 1. Archimedes principle was
employed to determine the density of coconut
fibre from where the composite samples are
designed following the method of Okafor et al.
[10] and ASTM Standards for mechanical
properties tests. Table 1 shows three grades of
fibre particle sizes and their corresponding sieve
sizes according to ASTM Standard.
To cope with the obvious limitations of polymers,
for example, low stiffness and low strength, and
to expand their applications in different
engineering areas, different types of particulate
fillers are often added to process polymer
composites, which normally combine the
advantages of their constituent phases [6].
Nakamura and Okubo [7] stated that
reinforcement of polymers by particulates plays
an important role in the improvement of
mechanical properties of high performance
materials.
2.1 Coconut
Fibre
Treatment
Extraction
and
It must be noted that because of high processing
viscosity of thermoplastic polymers, a proper
wetting of fibres is difficult. High temperatures of
up to 170°C can also cause unwanted changes
of the fibre surface or even destroy the fibres.
Natural fibres will only act as fillers in
thermoplastic polymers without improving any
quality if compatiblizers are not added.
Treatment is required to turn harvested plants
into fibres suitable for composite processing. The
first step is retting. After retting, hemicellulose
and lignin can be removed by hydro-thermolysis
or alkali reactions. The hemicellulose is
Natural fibre composites offer environmental
advantages such as reduced dependence on
non-renewable energy/material sources, lower
pollutant emissions, lower greenhouse gas
emissions, enhanced energy recovery and end of
life biodegradability of components [8]. Due to
poor compatibility of natural fibres, the surface of
the fibres must be treated to improve the
adhesion between the fibre and matrix. Bledzki
[9] reported many methods to modify the surface
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Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
responsible for a great deal of the moisture
absorption.
ܸோ =
1
2
3
ASTM
number
325
270
200
Sieve size
ܸ௙௥ =
45 micron (0.045 mm)
53 micron (0.053 mm)
75 micron (0.075 mm)
ܸோ =
Source: Annual book of ASTM Standards 2013
S/N Mechanical ASTM
test
standard
1
Tensile test ASTM
D638
2
Elastic
ASTM
Modulus
D638
3
Flexural
ASTM
Strength
D790
4
Impact
ASTM
Strength
D256
5
Hardness
ASTM
(Rockwell)
D785
(7)
Specification
of size
60x6x3 mm
60x6x3 mm
80x12.5x3 mm
120x10x4 mm
80x10x4 mm
Source: Annual Book of ASTM Standard 2013 [12]
(1)
By using volume fraction of fibres 5%, 10%, 15%,
20%, 30%, and 40% and applying ASTM
standard specifications from Table 2 in equations
2 to 7 above, yields Tables 3 to 6.
Calculation of volume of coconut fibre is
achieved following the derivations from rule of
mixtures based on the procedures of Jones and
Barbero [11] and implementation of Archimedes
principle applying equations (2) to (7) as
expressed in Okafor et al. [10].
‫ܯ‬௙
ߩ௙
ܸ௙ (1 − ܸ௙௥ )
ܸ௙௥
Table 2. ASTM standards for mechanical tests
2.2.1 Determination of fibre volume
ܸ௙ =
(6)
‫ܯ‬௙ = Mass of Coconut Fibre, ܸ௙ = Volume of
Coconut Fibre, ߩ௙ =Density of Coconut Fibre,
ܸ௙௥ = Volume Fraction of Fibre, ‫ܯ‬ோ = Mass of
Resin, ܸோ = Volume of Resin, ߩோ = Density of
3
Resin = 0.97 g/cm , ‫ܯ‬௖ = Mass of ASTM
Specified Sample Size, ܸ௖ = Volume of ASTM
Specified Sample Size.
The calculation of the volume of an irregular
object (such as coconut fibre) from its
dimensions is a mirage by traditional method.
Such a volume can be accurately measured
following Archimedes principle that the volume of
water displaced is equal to the volume of the
object immersed [10]. Following Archimedes
Principle, the density of fibre is expressed as:
‫ܯ‬௖ = ‫ܯ‬௙ + ‫ܯ‬ோ
ܸ௙
ܸ௙
=
ܸ௖
ܸ௙ + ܸோ
Where,
2.2 Composite Design
‫ܯ‬௙
ܸ௙
(5)
Equation (7) means that once the volume of fibre
is determined by Archimedes principle and the
volume fraction decision is taken, then volume of
resin can be calculated.
A certain quantity of the coconut fibre extracted
was dried under sun for 5 days and further dried
in an oven at 50oC for 1 hour without surface
treatment. The remaining portion of the fibre was
soaked with 4% NaOH and 2% Na2SO3 solution
for 24 hours. These fibres were washed with
distilled water and dried under sun for days. To
further remove any trace of moisture, the fibres
were further dried in an oven at 50°C for one
hour. The untreated coconut fibre was labeled A
while the treated one was labeled B. Both grades
of fibre were ground to a fine powder using
electrical milling machine and then sieved unto a
set of sieves arranged in descending order of
fineness.
ߩ௙ =
(4)
ܸ௖ = ܸ௙ା ܸோ
Table 1. Sieve sizes
Grade
‫ܯ‬ோ
ߩோ
2.3 Sample Preparation
The aggregates were mixed thoroughly until
even dispersion was achieved. Addition of 1%
weight of chromium catalyst was made and
stirred for 3 minutes, after which 2% weight of
accelerator (Cobalt Octoate) was added and
stirred for another 3 minutes before pouring the
composite mixture into the hopper of the injection
moulding machine where the already prepared
mould is fitted. The mould was cleaned with
(2)
(3)
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Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
acetone and coated with polyvinyl alcohol (PVA)
and allowed to dry before fixing it on the injection
moulding machine. This was done to prevent
particles of the composite sticking to the walls of
the mould which may alter the dimensional
accuracy of the samples produced. The
procedure was repeated for all the samples
produced with changes in the percentage of
ground coconut fibre based on volume fraction
decision and particle sizes. Barrel temperature
set-points of rear zone, middle zone, and nozzle
zone of the injection moulding machine was kept
at 150°C, 180°C and 200°C respectively. Screw
speed was set to 240 rpm and injection speed
was around 1 m/s. All the samples prepared
were kept at room temperature for 48 hours prior
to testing to promote relaxation of stress [1]. The
tensile strength, elastic modulus, flexural
strength, impact strength and hardness value of
each of the samples developed were determined.
Five samples in each case were tested and the
average value recorded.
2.4 Testing Program
2.4.1 Tensile test
The tensile properties investigated in this
research are tensile strength and elastic modulus
using universal tensile testing machine (JJ Lloyd
London, capacity 1- 20 KN) at a crosshead
speed of 10 mm/min and an applied load of 5KN.
The result of tensile strength is presented in
Table 7, Fig. 1 and elastic modulus is presented
in Table 8, Fig. 2.
2.4.2 Flexural test
Flexural properties were investigated using the
same universal testing machine. Three-point
bending test was performed at a crosshead
speed of 12 mm/min considering a beam span of
50 mm. The result of flexural test is presented in
Table 9, Fig. 3.
Table 3. Tensile test composition data
Vfr
0.05
0.10
0.15
0.20
0.30
0.40
Mf (g)
0.0318
0.0636
0.0954
0.1272
0.1908
0.2544
Vf (cm3)
0.054
0.108
0.162
0.216
0.324
0.432
VR (cm3)
1.026
0.972
0.918
0.864
0.756
0.648
MR (cm3)
0.9952
0.9428
0.8905
0.8381
0.7333
0.6286
Table 4. Flexural test composition data
Vfr
0.05
0.10
0.15
0.20
0.30
0.40
Mf (g)
0.0884
0.1767
0.2651
0.3534
0.5301
0.7068
3
Vf (cm )
0.1500
0.3000
0.4500
0.6000
0.9000
1.2000
3
VR (cm )
2.8500
2.7000
2.5500
2.4000
2.1000
1.8000
MR (g)
2.7645
2.6190
2.4735
2.3280
2.0370
1.7460
Table 5. Impact test composition data
Vfr
0.05
0.10
0.15
0.20
0.30
0.40
Mf(g)
0.1414
0.2827
0.4241
0.5654
0.8482
1.1309
Vf (cm3)
0.240
0.480
0.720
0.960
1.440
1.920
4
VR (cm3)
4.560
4.320
4.080
3.840
3.360
2.880
MR (g)
4.4232
4.1904
3.9576
3.7248
3.2592
2.7936
Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
Table 6. Hardness test composition data
Vfr
0.05
0.10
0.15
0.20
0.30
0.40
Vf (cm3)
0.1600
0.3200
0.4800
0.6400
0.9600
1.2800
Mf (g)
0.0942
0.1885
0.2827
0.3770
0.5654
0.7540
VR (cm3)
3.0400
2.8800
2.7200
2.5600
2.2400
1.9200
MR (g)
2.9488
2.7936
2.6384
2.4832
2.1728
1.8624
2.4.3 Impact test
4. DISCUSSION
Charpy impact tester (Changteh China, model
JC-25, pendulum capacity of 4J at a test velocity
of 5 m/s) was used to determine the impact
strength of the specimens. V-notch depth of 2.5
mm and notch angle of 45° was cut on each of
the specimens prior to testing. The energy
transferred to the material can be inferred by
comparing the difference in the height of the
striker (hammer) before and after the fracture as
indicated on the impact meter. The result of
impact test is presented in Table 10, Fig. 4.
Fig. 2 from Table 7 shows that the addition of
coconut fibre particles improved tensile yield
strength but only at certain concentrations.
Improvement up to 15.5% was obtained from
about 24.6 MPa to 28.4 MPa for the untreated
fibre and 18% was obtained from 24.6 MPa to
29.0 MPa for the treated fibre. Tensile strength
did not change much with coconut fibre
concentration up to 10-15%. Significant increase
in strength was obtained with 45 micron and 53
micron coconut fibre particles when their
concentration exceeded 15% for both the
untreated and treated fibre. This reflected the
contribution made by the fibre to impart its own
property to the polymer. Thus, strength increased
with fibre concentration and fibre treatment. This
is possible when there is good adhesion between
the coconut fibre particles and the polymer
matrix. In the case of coconut fibre with the
smallest particle size (45 microns), increased
surface area might have allowed for better fillermatrix interaction thus increasing the chances to
enhance the strength.
2.4.4 Hardness test
Hardness of a material is defined as its
resistance to permanent deformation, indentation
or scratching. The hardness values of the
developed samples were measured using
Rockwell Hardness Tester on M-Scale in
accordance with ASTM D785. The result of
hardness test is presented in Table 11, Fig. 5.
3. RESULTS
Fig. 3 from Table 8 also shows that the tensile
elastic modulus increases with volume fraction
treatment, but with decreased particle size with a
maximum optimum modulus of 800 MPa
The results obtained from the experiments are
shown from Tables 7-11 with their corresponding
graphs.
Table 7. Tensile strength of the 3 grades of untreated and treated coconut fibre filled HDPE
composite samples at specified fibre volume fractions
Vfr (%)
0
5
10
15
20
30
40
G1U
24.6
25.4
25.8
26.1
26.6
26.2
26.0
G2U
24.6
25.0
25.2
25.6
26.0
25.8
25.6
Tensile strength (MPa)
G3U
G1T
24.6
24.6
24.7
26.0
25.0
27.2
25.4
27.8
25.6
28.6
25.4
28.4
25.2
27.6
G2T
24.6
25.5
26.2
27.4
28.2
27.8
27.4
G3T
24.6
24.0
25.0
25.4
24.8
24.4
25.0
Where, ‫ܩ‬1ܷ =Untreated Grade 1 Composite Sample; ‫ܩ‬2ܷ = Untreated Grade 2 Composite Sample
‫ܩ‬3ܷ = Untreated Grade 3 Composite Sample; ‫ܩ‬1ܶ = Treated Grade 1 Composite Sample
‫ܩ‬2ܶ = Treated Grade 2 Composite Sample; ‫ܩ‬3ܶ =Treated Grade 3 Composite Sample
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Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
Tensile Strength (MPa)
29
28
G1U
27
G2U
26
G3U
25
G1T
24
G2T
23
0
10
20
30
40
50
G3T
Vfr (%)
Fig. 1. A plot of tensile strength of the 3 grades of untreated and treated coconut fibre filled
HDPE composite against fibre volume fractions
Table 8. Elastic modulus of the 3 grades of untreated and treated coconut fibre filled HDPE
composite samples at specified fibre volume fractions
Vfr (%)
G1U
480
500
530
580
650
780
610
Elastic Modulus (MPa)
0
5
10
15
20
30
40
Elastic modulus (MPa)
G3U
G1T
480
480
540
520
550
550
600
580
650
670
700
800
750
700
G2U
480
600
640
630
600
730
630
G2T
480
610
670
680
720
750
710
900
800
700
600
500
400
300
200
100
0
G3T
480
570
590
610
680
730
760
GIU
G2U
G3U
G1T
G2T
G3T
0
10
20
30
40
50
Vfr (%)
Fig. 2. A plot of elastic modulus of the 3 grades of untreated and treated coconut fibre against
fibre volume fraction
at volume fraction of 30%. This observation
supports earlier study made by Pukanszkyl [14]
that strength of the interaction between the filler
material and the matrix influences tensile
modulus of the composite. This is because
modulus is a phenomenon involving very small
strain values. Small stresses are produced by
application of small values of strain. Such small
stresses are not sufficient even to break the
weak interactions at the interface. Thus, these
small stresses can easily be transferred from
matrix to filler thereby allowing the filler to
contribute its high modulus to the composite.
Particle size also did not seem to influence the
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Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
elastic modulus. However, fluctuations in the
values of modulus were observed. These
fluctuations were more for highly filled HDPE
composites as is obvious from the graph.
obtained from 17.4 Mpa to 21.8 Mpa for
untreated coconut composite samples while an
increase of 28.5% from 17.4 MPa to 22.3 MPa
was obtained for the treated composite samples.
This could be attributed to the contribution of
high strength coconut fibre particles, thus
strength increased with increasing concentration
of the filler and also with fibre treatment. This
again is only possible if there is stress transfer
from matrix to filler through a fairly strong
interfacial bond. Further improvement in flexural
strength might be obtained by increasing the filler
concentration beyond 40%.
Fig. 4 from Table 9 shows that the flexural
strength of HDPE filled Coconut fiber fillers
increases with treatment, volume fraction, but
with decreased particle size of fillers with
maximum optimum value of 22.3 MPa at volume
fraction of 40%. The increase becomes more
pronounced when filler concentration went above
10%. A maximum of about 25.3% increase was
Table 9. Flexural Strength of the 3 grades of untreated and treated coconut fibre filled HDPE
composite samples at specified fibre volume fractions
Vfr (%)
G1U
17.4
18.3
18.7
20.1
20.0
21.4
21.8
0
5
10
15
20
30
40
Flexural Strenght (MPa)
G3U
G1T
17.4
17.4
17.3
18.4
17.4
18.8
17.8
20.8
19.0
20.6
20.6
21.8
20.8
22.3
G2U
17.4
18.0
18.1
19.6
19.3
20.1
21.3
G2T
17.4
18.0
18.5
19.6
19.5
20.0
21.6
G3T
17.4
17.3
17.5
18.2
19.0
19.8
21.0
Flexural Strenght
(MPa)
25
20
G1U
15
G2U
10
G3U
5
G1T
0
G2T
0
10
20
30
40
50
G3T
Vfr (%)
Fig. 3. A graph of flexural strength of the 3 grades of untreated and treated coconut fibre
against fibre volume fraction
Table 10. Impact strength of the 3 grades of untreated and treated coconut fibre filled HDPE
composite Samples at specified fibre volume fractions
Vfr (%)
0
5
10
15
20
30
40
G1U
48.0
49.0
50.0
51.0
53.0
50.0
48.0
G2U
48.0
49.0
49.2
49.5
50.0
48.0
46.0
Impact strength (J/m)
G3U
G1T
48.0
48.0
48.5
49.0
49.0
51.0
48.0
53.0
46.0
55.0
43.0
52.0
42.0
49.0
7
G2T
48.0
48.5
49.0
50.0
52.0
49.0
47.0
G3T
48.0
48.5
49.0
49.5
48.0
45.0
43.0
Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
Impact Strength
(J/m)
60
50
G1U
40
G2U
30
G3U
20
GIT
10
G2T
0
0
10
20
30
40
50
G3T
Vfr (%)
Fig. 4. A plot of impact strength of the 3 grades of untreated and treated coconut fibre against
fibre volume fraction
Table 11. Hardness value (HR) of the 3 grades of untreated and treated coconut fibre filled
HDPE composite Samples at specified volume fractions
Vfr (%)
0
5
10
15
20
30
40
Hardness values (HR)/Fibre particle sizes
G2U
G3U
G1T
G2T
12.5
12.5
12.5
12.5
14.8
14.3
15.8
15.4
20.5
18.0
23.2
21.4
26.3
24.4
32.0
28.6
32.6
30.2
46.5
36.2
40.4
37.5
52.6
44.8
47.8
43.6
54.0
48.6
G1U
12.5
15.3
22.4
30.5
38.3
46.8
53.4
G3T
12.5
15.0
19.2
26.4
32.4
40.2
42.8
Hardness Values
(HR)
60
50
G1U
40
G2U
30
G3U
20
G1T
10
G2T
0
0
10
20
30
40
50
G3T
Vfr (%)
Fig. 5. A plot of hardness values (HR) of the 3 grades of untreated and treated coconut fibre
filled HDPE composite samples against fibre volume fraction
Also Fig. 5 from Table 10 depicts that impact
strength increases with fibre treatment and
volume fraction but decreases with particle size
of filler at maximum optimum volume fraction of
20% with a value of 55 J/m. At higher fibre
concentrations and larger particle size, impact
strength was found to reduce. Further reductions
were checked probably by generation of
secondary cracks. In order to increase impact
strength of the composite further, suitable
surface treatment of the fibre was made which
increased the strength of the chemical bond
between the filler and the matrix.
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Ihueze et al.; JSRR, 9(3): 1-10, 2016; Article no.JSRR.20385
Table 12. Comparison of experimental results with standard results
Properties
Tensile strength (MPa)
Elastic modulus (MPa)
Flexural strength (MPa)
Impact strength (J/m)
Hardness (HR) Value
Values obtained from experiment at
maximum optimum fibre volume fraction for
the composite samples
G1U G2U
G3U
G1T
G2T
G3T
28.2
780
20.0
53.0
53.4
26.0
730
19.3
50.0
47.8
25.6
700
19.0
46.0
43.6
28.6
800
20.6
55.0
54
•
Furthermore, Fig. 6 from Table 11 clearly shows
that Hardness increases with volume fraction and
fibre treatment, but decreases with particle size.
The maximum optimum value of 54.0 HR was
recorded at 40% volume fraction. The hardness
value of the developed composite samples
increased as filler concentration increases for
both untreated and treated samples. Generally,
treated fibre composite specimens possess
greater hardness value than the untreated
samples. The increase in hardness is related to
the increasing amount of hard and brittle coconut
fibre particles in the polymer matrix and strong
interfacial bond between the fibre and the matrix.
These hard and brittle fibre particles will
continuously
resist
deformation
due
to
indentation. Also the smaller the particle size, the
harder the composite specimens.
•
Average
values
21.4
909
28.2
2.79
48.7
Developed composites can be applied for
applications requiring energy absorbtion
and dissipation such as in brake bands
and clutch plates
Developed composites can be applied for
applications requiring energy absorbtion
and dissipation such as autobodies.
Authors have
interests exist.
declared
that
no
competing
REFERENCES
1.
2.
3.
5. CONCLUSION
4.
It can be concluded that:
•
24.8
730
19.0
48.0
42.8
Range of
values
11.0-43.0
450- 1500
13.8-48.3
20.0-110.0
33.0-66.0
COMPETING INTERESTS
The values of experimental results are compared
with literature data obtained from MatWeb
(WWW.MATWEB.COM) for HDPE injection
molded grade and presented in Table 12 above.
The new material of HDPE shows increased
mechanical properties with volume fraction of
modified coconut fibres.
•
28.2
750
19.5
52.0
48.6
HDPE-Injection
molded (MatWeb)
At optimum condition of volume fraction
and particle size of coconut fibre-filler, the
coconut fibre reinforced HDPE (CFRP) has
28.6 MPa, 720 MPa, 22.3 MPa, 55.0 J/m
and 54.4 HR as optimum value for tensile
strength, elastic modulus, flexural strength,
impact strength and hardness.
Developed composites have shown
improved
mechanical properties as
compared with the unreinforced highdensity polyethylene resin.
5.
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_______________________________________________________________________________
© 2016 Ihueze et al.; This is an Open Access article distributed under the terms of the Creative Commons Attribution
License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any
medium, provided the original work is properly cited.
Peer-review history:
The peer review history for this paper can be accessed here:
http://sciencedomain.org/review-history/11904
10
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