fabrication and testing of palm fiber reinforced composite
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Transcript of fabrication and testing of palm fiber reinforced composite
CHAPTER 1
1.1 COMPOSITES:
INTRODUCTION
Composite materials are microscopic mixture of two or more
different materials, one typically being the continuous phase (matrix), and the
other being the discontinuous phase (reinforcement). A clear definition is,
Loose terms like “materials composed of two or more distinctly identifiable
constituents”. The main advantages of composite materials are their high
strength and stiffness, combined with low density, when compared with bulk
materials, allowing for a weight reduction in the finished part.
The composite materials derived from natural, renewable sources have
received significant interest in recent years due to increased environmental
awareness, concern about the depletion of non-renewable resources. The
primary advantages of natural fibers over synthetic fibers have been their low
cost, light weight, high specific strength, and biodegradability show in fig 1.1
Figure. 1.1 Composite material 1
1.1.1 NEED OF COMPOSITE MATERIAL:
There is unabated thirst for new material with improved desired
properties. All the desired properties are difficult to find in a single material.
For example, a material which needs high fatigue life may not be cost
effective.
The life of the desired properties depending upon the requirement of the
application is given below,
1. Strength
2. Stiffness
3. Toughness
4. High corrosion resistance
5. High wear resistance
6. High chemical resistance
7. Reduced weight
8. High fatigue life
9. Thermal& electrical insulation or conductivity
10. Energy dissipation
11. Reduced cost
The list of desired properties are in-exhaustive. It should be noted that
the most important characteristics of composite material is that their
properties are satisfied, that is one can design the required properties.
2
1.1.2 TYPES OF COMPOSITES
Particle-reinforced
(i) Large – particle
(ii) Dispersion - strengthened
Fiber - reinforced
(i) Continuous
(ii) Discontinuous
(a) Aligned
(b) Randomly oriented
Structural
(i) Laminates
(ii) Sandwich panels
Particulate composite
Particulate composites are composed of particle of one or more
material is suspended in a matrix of another material to make the material
stronger.
Fiber reinforced composite
Fiber reinforced composite are the long fiber of one material is
embedded in the matrix of other material which turns out to be extremely
strong.
3
Structural composite
Structural composite are layer of two or more different material
are bonded together by sandwiching two layers of strong.
1.1.3 APPLICATION OF COMPOSITE:
Piping for chilled water will need much less insulation or even none
in some cases.
Low mass skips and hoisting ropes.
Low mass and high capacity breathing apparatus in cylinders
Corrosion resistant air handling equipment.
Slurry transport.
Ventilation ducting.
Thermal insulation cladding.
Hydro power piping.
Corrosive fluid handling and storage.
Corrosion resistant cable trays and gratings.
Blast protection.
Water hydraulics.
Air actuators.
Chemical resistant piping and tanks for platinum refining.
Insulation cladding for chilled water transport.
Ventilation ducting.
The coal mining industry makes extensive use of GRP composite
pipes for fresh water, acid water and slurries. GRP replaced mild
steel and wood incapable of handling corrosion associated with
4
sulfuric acid. Successful installations can be found at Eastern
Associated Coal, Consolidated Coal, North American Coal, Carbon
Fuel and many others.
1.2 FIBER
Fibers are the principal constituents in a fiber-reinforced composite
material. They occupy the largest volume fraction in a composite laminate
and share the major portion of the load acting on a composite structure.
Proper selection of the fiber type, fiber volume fraction, fiber length, and fiber
orientation is very important, since it influences the following characteristics
of a composite laminate:
(i) Density
(ii) Tensile strength and modulus
(iii) Compressive strength and modulus
(iv) Fatigue strength as well as fatigue failure mechanisms
Fibers that make up fabrics used in every- day life can be best
understood as the building blocks of textile and clothing goods. The
durability and success of fabrics used in clothing and home furnishings
depend on the fiber used. Fibers resemble a fine, hair-like structure that is
able to with- stand the rigorous manufacturing required from design to
distribution (Cohen & John- son, 2010). For thousands of years individual-
also and families have been using natural fibers for clothing, cording, home
furnish- INS, and much more
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If the fibers used in a composite are very long and unbroken or cut then
it forms a continuous fiber composite. A composite, thus formed using
continuous fiber is called as fibrous composite.
The fibers are chopped into small pieces when used in fabricating a
composite. A composite with short fibers as reinforcements is called as short
fiber composite show in fig 1.2.
Figure. 1.2 Fiber
1.2.1 TYPES OF FIBERS
The fiber is classified into two types as follows,
• Synthetic fiber
• Natural fiber
6
1.2.1.1 Synthetic Fiber:
Synthetic fibers made from cellulose and manufactured from
chemicals derived from petroleum. These are made from synthesized
polymers or small molecules. The main raw materials are petroleum based
chemicals or petrochemicals. Their main properties are heat sensitive,
resistant to most chemicals, low moisture absorbency, easy to wash and
maintain, flame resistant. They are more expensive but can supply the world‟s
demand.
The synthetic fiber include that is various fibers as follow,
a. Glass fiber
b. Carbon fiber
c. Boron fiber
d. Ceramic fiber
e. Silicon carbide
f. Aramid fiber
g. Quartz and silica
1.2.1.2 Natural Fibers:
Example of natural fiber is jute, flax, sisal, hemp, hemi, cotton fiber,
coconut fiber (coir), and banana fiber (abaca). All these fibers are growth in
agricultural plants in various parts of the world and are commonly used for
making ropes, carpet backing, bags, and so on. The components of natural
fibers are cellulose micro fibrils dispersed in an amorphous matrix of lignin
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and hemicellulose. Depending on the type of the natural fiber, the cellulose
contents is in the range of 60-80 wt.% and the lignin content is in the range of
5-20 wt.%. In addition, the moisture content in natural fibers can be up to
20%.
1. Plant fiber:
Seed fiber (Cotton)
Leaf fiber (Sisal, Pineapple)
Bast fiber (Flax, Ramie, Hemp)
Fruit fiber (Coir)
Stalk fiber (Rice)
2. Animal fiber:
Animal hair
Silk fiber
3. Mineral fiber:
Amosite , Crocidolite, Tremolite, Actinolite, Anthophylite,
Chrysolite
1.2.2 Classification of Natural Fibers
Fibers are a class of hair-like material that are continuous
filaments or are in discrete elongated pieces, similar to pieces of thread.
8
They can be spun into filaments, thread, or rope. They can be used as a
component of composites materials. They can also be matted into sheets to
make products such as paper or felt. Fibers are of two types: natural fiber
and manmade or synthetic fiber. Figure 1 shows the classification of natural
fibers show in fig 1.3.
Figure. 1.3 Classification of natural fiber
1.2.3 Applications of Natural Fiber Composites
The natural fiber composites can be very cost effective material for
following applications:
Building and construction industry: panels for partition and false
ceiling, partition buildings which can be used in times of natural calamities
such as floods, cyclones, earthquakes, etc.
Storage devices: post-boxes, grain storage silos, bio-gas containers, etc.
Furniture: chair, table, shower, bath units, etc.
Electric devices: electrical appliances, pipes, etc.
Everyday applications: lampshades, suitcases, helmets, etc.
9
Transportation: automobile and railway coach interior, boat, etc.
The reasons for the application of natural fibers in the automotive
industry include:
Low density: which may lead to a weight reduction of 10 to 30%?
Acceptable mechanical properties, good acoustic properties.
Favorable processing properties, for instance low wear on tools, etc.
Options for new production technologies and materials.
Properties
Chemical analysis of palm fiber shows high cellulose content as
seen from Table 1. The hemi- cellulose content is quite low when
compared with other natural fibers. Cellulose content is responsible for
long fiber chain that ranges (28-53) % for palm fibers.
Table No:1.1
FIBER
CHEMICAL PROPERTIES
HEMI CELLULOSE
%
CELLULOSE
%
LIGNIN %
WAX
%
PALM LEAF
STALK
PALM LEAF
SHEATH
PALM
PETIDE
40-52 40-43 - -
28 25 45 -
30 14 28 -
PALM FRUIT 53 12 21 0.8
PINE APPLE LEAF 70-83 - 5-12.7 -
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Physical properties
The Physical properties of natural fibers in comparison with
palm fibers were presented in the
Table No:1.2
Physical properties
Fiber
Density
(g/cm3)
Elongation
(%)
Tensile
strength
(MPa)
Young’s
modulus
(GPa)
2.50-
Palm leaf stalk 1-1.2 2-4.50 97-196 5.40
Palm leaf sheath 1.20-1.30 2.84 220 4.8
Palm petiole 0.7-1.55 25 248 3.24
Palm fruit 1.09 28 423 6.-8.
Coir 1.15-1.2 30 175 4.-6.
Pineapple leaf 0.80-1.60 14.5 144 400-627
3.3.1. Fiber density.
Fiber Vs Density
2
1.5
1
0.5
0
1.2 1.3
1.55
1.09 1.2
1.6 palm leaf stalk
palm leaf sheath
palm petiole
palm fruit
Coir
Pineapple leaf
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Tensile strength
Figure 4 shows the tensile strength of palm fibers and few
natural fibers. The tensile behavior of the palm fibers increases with
increase in gauge lengths from 10 mm to 40 mm. As the gauge
length increases the deviation from the mean value for various
samples increases, which was expected for any natural fiber
characterization. The variation in Young‟s modulus was rather high
which is due to artifacts.
Fiber Vs Tensile strength
500
450
400
350
300
250
200
150
100
50
0
196
220
248
Fiber
423
175
144
palm leaf stalk
palm leaf sheath
palm petiole
palm fruit
Coir
Pineapple leaf
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1.3 RESIN:
Composites are a combination of fiber reinforcement and a
resin matrix. The resin system holds everything together, and transfers
mechanical loads through the fibers to the rest of the structure. In addition
to binding the composite structure together, it protects from impact,
abrasion, corrosion, other environmental factors and rough handling.
Resin systems come in a variety of chemical families, each designed and
designated to serve industries providing certain advantages like economic,
structural performance,resistance to various factors, legislation
compliance, etc. Only the most common resins of the below. Those are
Polyester (orthophthalic and isophthalic), vinyl ester, epoxy, and phenolic.
Fibermax Composites carries only epoxy resin systems thermoses family
and the ones mostly used in composite construction are described show in
fig 1.4
Figure. 1.4 Resin with hardener
13
1.3.1 TYPES OF RESIN
1.3.1.1 Polyesters:
Unsaturated polyester resins are the simplest, most economical
resin systems that are easiest to prepare and show good performance.
Millions of tons of this material is used annually around the world.They
are manufactured by the condensation polymerization of various idols
(alcohols) and dibasic acids (e.g. malefic anhydride or numeric acid) to
give esters, a very viscous liquid that is then dissolved in styrene, a
reactive monomer. Styrene lowers the viscosity to a level suitable for
impregnation or lamination. Applications include transportation markets
(large body parts for automobiles, trucks, trailers, buses), marine (small
and large boat hulls and other marine equipment), building (panels,
bathtub and shower shells), appliances etc.
1.3.1.2 Orthophthalic:
Is also referred to as Roth or General Purpose Polyester
(GP) was the original polyester developed. It has the lowest cost and is
still very widely used in FRP industry . It is commonly used in
applications where high mechanical properties, corrosion resistance, and
thermal stability are not required. Although the upper temperature limit is
only 50oC, it performs satisfactory in water and sea water. It is normally
not recommended for use in contact with chemicals.
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1.3.1.3 Isophthalic:
Often referred to as ISO, it is improved polyester. It has a slightly
higher cost, improved strength, thermal stability(55oC) and mild resistance
to corrosion conditions. Improved resistance to water permeation has
prompted its use as a gel barrier coat in marine applications. Improved
chemical resistance has led them to extensive use in underground
petroleum tanks (in gas stations) with satisfactory service life. They are
also used in salts and mild acids.
1.3.1.4 Vinylester:
Even further improved polyester, it is biphenyl chlorinated, or a
combination of polyester and epoxy. Its curing, handling and processing
characteristics are those of polyester, and it exhibits higher test results in
corrosion temperature resistance and strength and has higher cost.
Modifications of the molecule have produced even higher properties.
1.3.1.5 Phenolic:
Phenolic resin is a reaction of phenol and formaldehyde. It can be
cured via heat and pressure, without the use of catalysts or curing agents.
It is one of the oldest thermosetting resins available and sells at a very
reasonable cost. Cured phenolic resins are fire resistant without the use of
mineral fillers or fire retardant additives. Phenolic composites have
excellent high-temperature properties and if properly formulated and
cured, they can form carbon to carbon composites with outstanding
temperature resistance. Phenolics are also unique in their chemical
resistance. The use of phenolic resins in composites is growing, primarily
15
due to regulative legislation on flame spread, smoke generation, and
smoke toxicity. It is used extensively in automobiles, appliances,
electronics, and as an industrial adhesive both in higher and lower
temperature applications.
1.3.1.6 Epoxy :
Epoxy resins are a broad family of materials. The most common ones are
prepared from the reaction of bis-phenol A and epichlorohydrin and contain a
reactive functional group in their molecular structure. Epoxy resin systems
show extremely high three dimensional crosslink density which results to the
best mechanical performance characteristics of all the resins. The most
demanding strength/weight applications use epoxy almost exclusively. It has
excellent strength and hardness, very good chemical heat and electrical
resistance. Also, often heat curing is required.) Epoxy systems are used in
applications like aerospace, defense, marine, sports equipment, adhesives,
sealants, coatings, architectural, flooring and many others .More information
about epoxies and Fibermax Composites systems.
1.3.1.7 Gel coats
Gel coats are prepared from a base resin and additives. The base resin
can be polyester, vinyl ester, phenolic or epoxy. Additives are thyrotrophic
agents, fillers, pigments and other. The gel coat, as the name implies, has a gel
texture. This makes the gel coat capable to “stay” on vertical surfaces of
molds without draping. It is placed f irst in the mold, so it becomes the outer
surface.
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1.3.2 APPLICATION
It is applicable for joining the slabs.
It is mixed with the paint for painting.
Resins are used in reinforced composite material for joining
purpose.
There also used for connecting pipe lines.
1.3.3 Properties:
Epoxy resins are stronger than polyester resin and vinyl ester
resin. Epoxy resin having a matrix chain linkage structure so it provides high
bonding strength.
• Some of the most important properties include:
• Water and chemical resistance
• Electrical stability
• Thermal stability
• Toughness
• Low volatiles during manufacture
• Low shrinkage
Features
• MeetsUL94V-0 approval
• Low shrinkage
• Good chemical and water resistance
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• Non-toxic
• Free of abrasive fillers, low wear on dispensing machinery
Typical Properties:
Liquid Properties: BaseMaterial
Epoxy
Density Part A-Resin(g/ml) 2.25
Density Part B-Hardener(g/ml) 0.94
Part A Viscosity (mPa 23°C) 200000
Part B Viscosity (mPa 23°C) 58
Mix Ratio (Weight) 17.31:1
Mix Ratio (Volume) 7.23:1
Usable Life(20°C) 90mins Gel Time(23°C)5hours
Cured System: Thermal Conductivity(W/mK) 1.26
Cured Density (g/ml) 2.09
Mixed System Viscosity (mPa 23°C) 16700
Temperature Range(°C) -40to+130
Max Temperature Range (Short Term °C / 30 Mins)
(Application and Geometry Dependent) +150
Dielectric Strength(kV/mm) 10
Volume Resistivity (ohm-cm) 1015
Shore Hardness D80
Colour (Mixed System) White
Flame Retardency Yes 18
Tensile Strength(MPa) 82
Compressive Strength(MPa) 120
Deflection Temperature(°C) 60
1.3.4 HARDENER
A substance mixed with paint or other protective covering to make the
finish hardener or more durable. A chemical used to raise the melting point of
an emulsion show in fig 1.5
Figure. 1.5 Hardener
19
CHAPTER 3
WORKING METHODOLOGY
3.1 PREPARATION OF PALM FIBER:
The palm fibers are easily available in all places. The palm tree
were extracted by either retting in water and/or mechanical processing or hand
picking methods are used. The fiber were cleaned with water after soaking for
two weeks. The fiber were further dried in natural sunlight to remove
moisture content and long uniform fiber were obtained. Then the fiber is
separate in the equal dimensions for producing a composite material. The
palm fibers were available plenty from INDIA fibers . The fibers were
further dried in natural sunlight to remove moisture content and long
uniform fibers were obtained (Fig. 3.1).
Palm leaf stalk fiber Palm fruit fiber
Palm leaf sheath fiber Palm petiole fiber
Figure. 3.1 Fiber extraction
25
3.2 PREPARATION OF RESIN:
When in Resin pack form, the resin and hardener are mixed by
removing the clip and moving the contents around inside the pack until
thoroughly mixed. To remove the clip, remove both end caps, grip each
end of the pack and pull apart gently. By using the removed clip, take
special care to push unmixed material from the corners of the pack.
Mixing normally takes from two to four minutes depending on the skill of
the operator and the size of the pack. Both the resin and hardener are
evacuated prior to packing so the system is ready for use immediately after
mixing. The corner may be cut from the pack so that it may be used as a
simple dispenser show in fig 3.2.
Figure. 3.2 Preparation of resin
26
3.3 MOULD BOX:
In our project the molding box is manually prepared .The mould box
is made in the natural wood . This type of mould is prepared for medium size
jobs and its smooth surface show in fig 3.3 .
Figure. 3.3 Molding box
Dimension of Molding Box :
Length : 45 cm
Breath : 40 cm
Height : 3 cm
27
3.4 WORKING:
The mounding box is manually prepared by using sheet metal. And
the wax is coated bottom side .The resin is mixed with the hardener due to the
increasing the hardness properties of resin. The palm is fiber is collected
manually and it is cut required size. The wax is used for easily removing the
composite material from the mould box.
Inside the mould box the resin and fiber are pasted alter natively like
a layer .The wax is pasted before the first layer and also after the last layer .It
takes 24hr for complete the work in atmosphere .After completion of work the
job is includes the test of temperature, hardness and impact.
Mold preparation:
The composite were manufactured in a metal mold of 900mm X
450mm X 10mm. The fabrication of the composite material was carried
out through the hand-layup technique. The top and bottom plate surface of the
mold and the walls were coated with remover and allowed to dry. The top and
bottom plates are to be covered and press the fiber after the epoxy resin is
applied.
Product Description
ER2074 is a flame retardant, thermally conductive , two part potting
and encapsulating compound. The flame retardant technology used is of a
„clean‟ type leading to relatively low toxicity fumes and low smoke
emission.
28
Fiber density
The fiber density is calculated by using pycnometer having to line as
density comparing element, the density of palm fiber is(1-1.2 g/cm3). The
investigated palm fiber was found to have an average density of (0.7-1.55
g/cm3) which is significantly lower than wield used synthetic fibers such as
E-glass fiber(2.5 g/cm3) and carbon fiber (1.4-1.8 g/cm3).
Tensile strength of fiber
The tensile test was conducted using UTM as per the ASTM standard
for all fibers. The fibers with gauge length of 20mm, 30mm, 40mm and
50mm are tested. A constant cross head speed of 0.1mm/min was used for the
testing.
Fiber reinforcement composite:
Fiber reinforced composite material consist of fibers of high strength
and modules embedded in or bonded with distinct interfaces (boundaries)
between them. Common fiber reinforced composites are composed of fibers
and a matrix. Fibers are the reinforcement and the main source of strength
while matrix glues all the fibers together in shape and transfers stresses
between the reinforcing fibers. Sometimes, filler might be added to smooth
the manufacturing process, impact special properties to the composites, and or
reduce the product cost. The principal fibers in commercial use are various
types of glass and carbon as well as Kevlar 49. Other fibers, such as boron,
silicon carbide, and aluminum oxide, are used in limited quantities.
29
Fiber orientation in each layer as well as the stacking sequence of
various layers in a composite laminate can be controlled to generate a wide
range of physical and mechanical properties for the composite laminate.
3.5 CHARACTERISTICS OF PALM FIBER:
Palm fibers are a composite material designed by nature. The
fibers are basically a rigid, crystalline cellulose micro fibril-reinforced
amorphous lignin and/or with hemi cellulosic matrix. Most plant fibers are
composed of cellulose, hemicelluloses, lignin, waxes, and some water-
soluble compounds. The percentage composition of each of these
components varies for different fibers. Generally, the fiber contains 60-80
% cellulose, 5-20% lignin and up to 20% moisture. During the biological
synthesis of plant cell walls, polysaccharides such as cellulose. This
lignification‟s process causes a stiffening of cell walls and the carbohydrate
is protected from chemical and physical damage show in fig 3.4.
Figure .3.4 Palm fiber
30
CHAPTER 4
TESTING METHODS
4.1 HARDNESS TEST:
Hardness is the property of a material that enables it to resist plastic
deformation, usually by penetration. However, the term hardness may also
refer to resistance to bending, scratching, abrasion or cutting.
Measurement of Hardness:
Hardness is not an intrinsic material property dictated by precise
definitions in terms of fundamental units of mass, length and time. A hardness
property value is the result of a defined measurement procedure.
Hardness of materials has probably long been assessed by resistance to
scratching or cutting. An example would be material B scratches material C,
but not material A. Alternatively, material A scratches material B slightly and
scratches material C heavily. Relative hardness of minerals can be assessed by
reference to the Moh's Scale that ranks the ability of materials to resist
scratching by another material. Similar methods of relative hardness
assessment are still commonly used today. An example is the file test where a
file tempered to a desired hardness is rubbed on the test material surface. If
the file slides without biting or marking the surface, the test material would be
considered harder than the file. If the file bites or marks the surface, the test
material would be considered softer than the file.
The above relative hardness tests are limited in practical use and do
not provide accurate numeric data or scales particularly for modern day
metals and materials. The usual method to achieve a hardness value is to
31
measure the depth or area of an indentation left by an indenter of a specific
shape, with a specific force applied for a specific time. There are three
principal standard test methods for expressing the relationship between
hardness and the size of the impression, these being Brinell, Vickers, and
Rockwell. For practical and calibration reasons, each of these methods is
divided into a range of scales, defined by a combination of applied load and
indenter geometry.
Hardness Test Methods:
Rockwell Hardness Test
Rockwell Superficial Hardness Test
Brinell Hardness Test
Vickers Hardness Test
Microhardness Test
Moh's Hardness Test
Scleroscope and other hardness test methods
4.1.1 Rockwell Hardness Test
The Rockwell hardness test method consists of indenting the test
material with a diamond cone or hardened steel ball indenter. The
indenter is forced into the test material under a preliminary minor load F0
usually 10 kgf. When equilibrium has been reached, an indicating device,
which follows the movements of the indenter and so responds to changes
in depth of penetration of the indenter is set to a datum position. While
the preliminary minor load is still applied an additional major load is
applied with resulting increase in penetration. When equilibrium has
again been reach, the additional major load is removed but the
32
preliminary minor load is still maintained. Removal of the additional
major load allows a partial recovery, so reducing the depth of penetration
The permanent increase in depth of penetration, resulting from the
application and removal of the additional major load is used to calculate
the Rockwell hardness number.
HR = E - e
F0 = preliminary minor load in kgf
F1 = additional major load in kgf
F = total load in kgf
e = permanent increase in depth of penetration due to major load F1
measured in units of 0.002 mm
E = a constant depending on form of indenter: 100 units for diamond
indenter, 130 units for steel ball indenter
HR = Rockwell hardness number
D = diameter of steel ball
33
Diagram of Rock Well Hardness Testing Machine
Figure. 4.1 Rockwell Hardness test
CALCULATION:
Table No:4.1
Specimen Indenter Load RHN Average
Composite
material 1/16
100 65
100 75
100 67
67.3
34
4.1.2 The Brinell Hardness Test
The Brinell hardness test method consists of indenting the test
material with a 10 mm diameter hardened steel or carbide ball subjected
to a load of 3000 kg. For softer materials the load can be reduced to 1500
kg or 500 kg to avoid excessive indentation. The full load is normally
applied for 10 to 15 seconds in the case of iron and steel and for at least
30 seconds in the case of other metals. The diameter of the indentation
left in the test material is measured with a low powered microscope. The
Brinell harness number is calculated by dividing the load applied by the
surface area of the indentation.
The diameter of the impression is the average of two readings at right
angles and the use of a Brinell hardness number table can simplify the
determination of the Brinell hardness. A well structured Brinell hardness
number reveals the test conditions, and looks like this, "75 HB
10/500/30" which means that a Brinell Hardness of 75 was obtained
using a 10mm diameter hardened steel with a 500 kilogram load applied
for a period of 30 seconds. On tests of extremely hard metals a tungsten
carbide ball is substituted for the steel ball. Compared to the other
hardness test methods, the Brinell ball makes the deepest and widest
indentation, so the test averages the hardness over a wider amount of
material, which will more accurately account for multiple grain structures
and any irregularities in the uniformity of the material. This method is
the best for achieving the bulk or macro-hardness of a material,
particularly those materials with heterogeneous structures.
35
Diagram of Brinell Hardness Testing Machine
Figure. 4.2 Brinell hardness test
Table No:4.2
Specimen Load Diameter of
Specimen
Area
In mm^2
BHN
Composite 100
100
100
1.3 0.676 147.84
36
CALCULATION:
BHN= P/A
A= (πD)/2 (D- (D^2-d^2))
D=1.5mm
d=1.3
BHN=56 Kgf
4.1.3 Vickers Hardness Test
The Vickers hardness test method consists of indenting the test
material with a diamond indenter, in the form of a right pyramid with a
square base and an angle of 136 degrees between opposite faces
subjected to a load of 1 to 100 kgf. The full load is normally applied for
10 to 15 seconds. The two diagonals of the indentation left in the surface
of the material after removal of the load are measured using a microscope
and their average calculated. The area of the sloping surface of the
indentation is calculated. The Vickers hardness is the quotient obtained
by dividing the kgf load by the square mm area of indentation.
F = Load in kgf d = Arithmetic mean of the two diagonals, d1 and d2 in
mm
HV = Vickers hardness
37
When the mean diagonal of the indentation has been determined
the Vickers hardness may be calculated from the formula, but is more
convenient to use conversion tables. The Vickers hardness should be
reported like 800 HV/10, which means a Vickers hardness of 800, was
obtained using a 10 kgf force. Several different loading settings give
practically identical hardness numbers on uniform material, which is
much better than the arbitrary changing of scale with the other hardness
testing methods. The advantages of the Vickers hardness test are that
extremely accurate readings can be taken, and just one type of indenter is
used for all types of metals and surface treatments. Although thoroughly
adaptable and very precise for testing the softest and hardest of materials,
under varying loads, the Vickers machine is a floor standing unit that is
more expensive than the Brinell or Rockwell machines.
There is now a trend towards reporting Vickers hardness in SI units
(MPa or GPa) particularly in academic papers. Unfortunately, this can
cause confusion. Vickers hardness (e.g. HV/30) value should normally be
expressed as a number only (without the units kgf/mm2). Rigorous
application of SI is a problem. Most Vickers hardness testing machines
use forces of 1, 2, 5, 10, 30, 50 and 100 kgf and tables for calculating
HV. SI would involve reporting force in newtons (compare 700 HV/30 to
HV/294 N = 6.87 GPa) which is practically meaningless and messy to
engineers and technicians. To convert a Vickers hardness number the
force applied needs converting from kgf to newtons and the area needs
converting form mm2 to m2 to give results in pascals using the formula
above.
38
4.2 IMPACT TEST:
An impact test is a technique for determining the behavior of
material subjected to shock loading in bending , tension and torsion. The test
designed to determine how a specimen of a known material will respond to a
suddenly applied stress .The test ascertains whether the material is to tough or
brittle. Impact test is also known as ASTM E23. The impact test is a method
for evaluating the toughness ,impact strength , and notch sensitivity of
engineering materials. They are basically two types of impact test ,pendulum
and drop weight show in fig 4.3.
Figure. 4.3 Impact test
39
CALCULATION:
1. Charpy
Table No:4.3
S.No Energy stored in
pendulum chamber
before striking the
specimen
(J)
Energy forced in
pendulum
(J)
Energy
absorbed by
the specimen
(J)
Impact
strength
(J/mm^2)
1 300 180 120 1.2
Material = composite
Size of the specimen = 10mm×10mm=100mm^2
Length of the specimen = 75mm
Breath of the specimen = 10mm
Thickness of the specimen = 10mm
Formula:
I = K/A
A = (d-d1)×b
I = 1.2 J/mm^2
40
2. Izod
Table No:4.4
S.No Energy stored in
pendulum chamber
before striking the
specimen
(J)
Energy forced in
pendulum
(J)
Energy
absorbed by
the specimen
(J)
Impact
strength
(J/mm^2)
1 164 152 12 0.12
CALCULATION:
Material = composite
Size of the specimen = 10mm×10mm=100mm^2
Length of the specimen = 75mm
Breath of the specimen = 10mm
Thickness of the specimen = 10mm
Formula:
I = K/A
A = (d-d1)×b
I = 0.12 J/mm^2
41
4.3 TEMPERATURE TEST:
Table No:4.5
S.No Area of specimen
mm^2
Minimum
Temperature
C
Maximum
Temperature
C
1 100 160 250
4.4 DEFLECTION TEST:
The deflection distance of a member under a load is directly
related to the slope of the deflected shape of the member under that load and
can be calculated by integrating the function that mathematically describes the
slope of the member under that load.
Deflection can be calculated by standard formula (will only give the
deflection of common beam configurations and load cases at discrete
locations), or by methods such as virtual work, direct
integration, Castiglione‟s method, Macaulay's method or the direct stiffness
method, amongst others show in fig :4.4
42
UTM MACHINE
Figure. 4.4 Deflection test
Calculation:
Table No:4.6
S.No Length of specimen
Energy absorbed by
mm the specimen Kg
1 52 77
43
CHAPTER 5
COMPARISION
Tensile Testing
The tensile test specimens were prepared according to
ASTMD 638. For testing the specimen was mounted in the grips of the
Instron universal tester with 10 mm gauge length. The stress strain
plotted during the test for the determination of ultimate tensile
strength and elastic modulus.
The tensile strength of palm fibers and few natural fibers. The
tensile behavior of the palm fibers increases with increase in gauge
lengths from 10 mm to 40 mm. As the gauge length increases the
deviation from the mean value for various samples increases,
which was expected for any natural fiber characterization. The
variation in Young‟s modulus was rather high which is due to artifacts.
Tensile strength, also known as Ultimate Tensile Strength (UTS),
44
FIBER COMBINATION vs PERCENTAGE
ELONGATION
13
12.5
12
11.5
11
10.5
10
9.5
palm coir
FIBER COMBINATION
Figure 1 Comparison of effect of fiber combination on percentage elongation
FIBER COMBINATION vs ULTIMATE STRESS
(N/mm2)
176
174
172
170
168
166
164
palm coir
FIBER COMBINATION
Figure 2 Comparison of effect of fiber combination on ultimate stress.
Flexural Properties
Figures 3 shows the flexural strength of palm based composite
and the coir based composite. From the results of flexural test, the palm
matrix composite shows better flexural property than coir matrix
composite.
45
FIBER COMBINATION vs FLEXURAL STRENGTH
N/mm2
124 123 122 121 120 119 118 117 116 115
palm coir
FIBER COMBINATION
Figure 3 Comparison of effect of fiber combination on flexural strength.
Impact Properties
The impact responses of both composites were presented in Figure
4. The Palm based composite posses higher impact strength that leads to
the higher toughness in the material. The Charpy impact test, also known as
the Charpy V-notch test, is a standardized high strain-rate test which
determines the amount of energy absorbed by a material during fracture.
This absorbed energy is a measure of a given material's
notch toughness and acts as a tool to study temperature-dependent ductile-
brittle transition.
46
FIBER COMBINATION vs IMPACT STRENGTH
8.1
8
7.9
7.8
7.7
7.6
7.5
7.4
7.3
7.2
palm coir
FIBER COMBINATION
Figure 4 Comparison of effect of fiber combination on Impact length.
Wear Properties
The figur represents the effect of fiber combination on the
weight loss of the specimen. It was observed that palm specimen
holding superior wear resistance on comparison with coir specimen.
Also the weight loss on coir based composite was higher than palm
based composites.
Wear can also be defined as a process where interaction
between two surfaces or bounding faces of solids within the working
environment results in dimensional loss of one solid, with or without
any actual decoupling and loss of material. Aspects of the working
environment which affect wear include loads and features such as
unidirectional sliding, reciprocating, rolling, and impact loads, speed,
temperature.
47
Rate of Weight loss due to wear
3
2.5
2
1.5
1
0.5
0
0.7 0.5
0.89
1.45
2.6 2.4
palm
coir
90 180 270 360
Time(sec)
Figure 5 Comparison of effect of fiber combination on rate of weight loss due to wear.
Moisture absorption Test
Figure 6 shows the comparison of rate of absorption of
moisture content between the two com- posites. It was observed that
Palm fiber composites absorbed less moisture on comparing with
coir fiber composites and holds a better result that they can be used in
areas where the require- ment is dry.
48
Rate of absorbtion of moisture content
0.2
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
7.3 15 22.3 30 37.3 45
palm
coir
49
COMPOSITION:
CALCULATION
Volume of mould = Area x Thickness
=40 x 45 x 1.4 c.m
=2520 c.m3
F=30% R =60% P=10%
Volume of fiber = 1716 X30/100 =514.8 c.m3
Volume of resin =1716 X60/100 =1029.6c.m3
Weight:
Volume of Powder = 1716 X10/100 =171.6c.m3
Weight of fiber = 200g
Weight of Resin
= 2 Kg
Weight of power
= 70g
Total weight = 2.270Kg
50
6. COST ESTIMATION
RESIN - 1500
HARDNER - 500
MOLDING BOX - 200
FIBER,BRUSH,WAX - 500
REPORT - 1200
TRANSPORT - 1000
TOTAL - 4900
51
7. CONCLUSION:
In our project contains 60% of resin 30% fiber and 10% of neem
powder . It is with stand up to 75kg of load . So it suitable for alternative of
slab in kitchen and shelf and also a coir applications.
52
REFRENCES:
[1] Wallenberger, F. T. & Weston, N. (2004) Natural. Fibers, Plastics
and Composites Natural,. Mate- rials Source Book from
C.H.I.P.S. Texas
[2] Satyanarayana, K. G., K. Sukumaran, P. S. Mukherjee, C.
Pavithran and S. G. K. Pillai. (1990), Natural Fiber–Polymer
Composites, J. Cement and Concrete Composites, 12(2) pp. .
[3] Satyanarayana, K.G., Sukumaran, K. Kulkarni, A.G. , Pillai,
S.G.K. andRohatgi, P.K. (1986). Fabri- cation and Properties of
Natural Fiber-reinforced Polyester Composites , Composties , 17:
[4] Gowda, T. M. Naidu, A. C. B. Chhaya, R. (1999) Some
Mechanical Properties of Untreated Jute Fabric-Reinforced
Polyester Composites, Journal of Composites Part A: Applied
Science and Manu- facturing, 30(3), pp. .
[5] Sastra, H, Siregar, J, Sapuan, S and Hamdan, M (2006),'Tensile
properties of Arenga pinnata fiber- reinforced epoxy composites,
Polymer-Plastics Technology and Engineering, vol. 45, no. 1, pp.
[6] Kazuya Okubo, Toru Fujii, & Yuzo Yamamoto. (2004).
Development of bamboo-based polymer composites and their
mechanical properties, Composites Part A: Applied Science
and Manufac- turing, 35 (3), 2004, .
[7] Antich, A. Vázquez, I. Mondragon and C. Bernal (2006).
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53