1. Study on effect of Reinforcement
of Keratin Fiber (human hair)
on HDPE
Bachelor of Technology
In
Plastic Technology
Central Institute of Plastics Engineering &
Technology, Lucknow UP 226008

2. Study on effect of Reinforcement of
Keratin Fiber (Human Hair) on HDPE
Bachelor of Technology
In
Plastic Technology
UNDER SUPERVISION OF: SUBMITED BY:
Mr. SANJAY CHAUDHARY SHUBHAM KR. GAUTAM
Mr. CHANDRASHEKHAR SHARMA
Central Institute of Plastics Engineering &
Technology, Lucknow UP 226008

3. ACKNOWLEDGEMENT
We avail this opportunity to extend my hearty indebtedness to my guide
Prof. Sanjay Chaudhary for their invaluable guidance, motivation, untiring
efforts and meticulous attention at all stages during Our course of work.
We also express my sincere gratitude to Mr. Maan Singh, Mr. Ravi Shukla,
Testing Department for their timely help during the course of work.
Our special thanks to Prof. Chandrashekhar Sharma for his support. I am also
grateful to all staff members of Processing department at C.I.P.E.T. Lucknow
for their co-operation.

4. ABSTRACT
Natural fibers have recently attracted the attention of scientists and
technologists because of the advantages that these fibers provide over
conventional reinforcement materials, and for which the development of natural
fibers composites has been a subject of interest for the past few years. These
natural fibers are low-cost fibers with low density and high specific properties.
These are biodegradable and non-abrasive, unlike other reinforcing fibers.
However certain drawbacks such as incompatibility with the hydrophobic
polymer matrix, the tendency to form aggregates during processing and poor
resistance to moisture greatly reduce the potential of natural fibers to be used as
reinforcement in polymer matrices.
The primary purpose of the study is to investigate the reinforcement
effect of Keratin Fiber (Human Hair) on High Density Polyethylene (HDPE).
In the present piece of research work, we have used Keratin fiber(Human
Hair) which are light. Short fibers obtained from human hair are found to
possess high impact resistance, strength, stiffness and hydrophobic nature.
Their low cost, low density and large aspect ratio can make them good
reinforcing materials in polymer matrix to make composites. Randomly
oriented short Keratin fibers with 1% weight percentage are reinforced into
HDPE matrix to prepare composite sheet. Flexural strength, Tensile strength of
keratin fiber composite are also evaluated.
Keywords: Natural fiber, Keratin fiber, Polymer Composite

5. TABLE OF CONTENT
LIST OF TABLES
LIST OF FIGURES
Chapter 1. Introduction
1.1 Motivation
1.2 Relevance of the Present Study
1.3 Background
1.4 Types of Composite Materials
1.5 Reinforcement
1.6 Types of Polymer Composites
1.7 Bio Fiber Reinforced Composites
1.8 Bio Fibers
1.9 Types of Bio Fibers
1.10 Mechanical Properties of Bio Fibers
1.11 Matrix Resins
Chapter 2. Literature Review
2.1 Natural Bio-Fiber Reinforced Composites
2.2 Keratin fiber
2.3 Structure and Properties
2.4 Polymer Keratin based fiber Composite

6. Chapter 3. Materials & Methods
3.1 Matrix Materials
3.1.1 Low Density Polyethylene
3.1.2 High Density Polyethlene
3.2 Composite Processing
3.2.1 Compression Molding
Chapter 4. Experimental Details & Results
4.1 Tensile Test of LDPE Film ASTM D882
4.2 Tensile Test of HDPE Sheet ASTM D638
4.3 Flexural Test of Reinforced HDPE Sheet ASTM D790
Chapter 5. Conclusions
5.1 Conclusions
5.2 Recommendation for future work
REFERNCES

7. LIST OF TABLES
1.4 Comparative properties of metals and polymeric matrix compositesa
(Mallick, 1993, p. 13)
1.10 Mechanical Properties of Bio Fibers (Source Ref. 9).
1.11 Property/process characteristics for thermoplastic and thermosetting
matrix systems.
1.11c Typical unfilled thermoplastic resin properties (Mazumdar, 2002, p. 53).
1.11b Typical unfilled thermosetting resin properties (Mazumdar, 2002, p. 48).

8. LIST OF FIGURES
2.3 Structure of hair at various length-scales.
4.1a Sample 1 of LDPE Reinforced film
4.1b Sample 2 of LDPE Reinforced film
4.1c Sample 3 of LDPE Reinforced film
4.1d Sample 4 of LDPE film

9. Chapter 1
Introduction

10. Chapter 1
Introduction
1.1 Motivation
Until the beginning of the nineteenth century, the materials developed,
manufactured and used, whether homogeneous or composite, were basically
inorganic in nature. Complex organic substances such as coal and oil were
subjected to destructive processes to produce simpler chemicals such as coal
gas and gasoline. However, during the twentieth century, organic chemists have
developed the means of reversing this destructive process and of creating from
the by-products materials that do not occur naturally. Most important among
these new substances are the ‗super-polymers‘, commonly called ‗plastics‘, a
term which in many cases is misleading, and the production of these materials
has increased dramatically since the Second World War.
The possibilities of using these plastic materials in engineering situations
are now being extensively examined, and in the field of structural engineering
such development is taking place mainly in their use as glass fiber-reinforced
plastics, the plastic material most widely used being polyester resin. A large
number of materials, e.g. jute, asbestos, carbon and boron, have been used for
the fiber reinforcement of the plastic matrix, the main function of the fibers
being to carry the majority of the load applied to the composite and to improve
the stiffness characteristics of the polymer matrix. The most widely used
material for the reinforcement of polymer is glass fiber in all its various forms,

11. partly because of its high strength and its low specific gravity, partly because of
its chemical inertness, and partly because of its being relatively inexpensive to
produce. Notwithstanding these, development of new higher modulus fibers
such as boron, graphite, silicon carbide, and beryllium gives us reinforcements
having several times the modulus of elasticity of glass fibers with densities as
low as or lower than glass and strengths close to that of glass fibers. In addition
to having available new chemical types of fibers, there are also a number of
options with regard to fiber diameter, fiber length, and grouping of filaments
into strands, roving, and yarn. These types and forms of fibers give us a new
degree of freedom in terms of being able to select the most appropriate type
fiber for a given application.
1.2 Relevance of the Present Study
A key feature of fiber composites that makes them so promising as
engineering materials is the opportunity to tailor the materials through the
control of fiber and matrix combinations and the selection of processing
techniques. Matrix materials and fabrication processes are available that do not
significantly degrade the intrinsic properties of the fiber. In principle, an infinite
range of composite types exists, from randomly oriented chopped fiber based
materials at the low property end to continuous, unidirectional fiber composites
at the high-performance end. Composites can differ in the amount of fiber, fiber
type, fiber length, fiber orientation, and possibly fiber hybridization. In general,
short-fiber composites are used in lightly loaded or secondary structural
applications, while continuous fiber-reinforced composites are utilized in
primary applications and are considered high-performance structural materials.

12. By nature, continuous-fiber composites are highly anisotropic. Maximum
properties can be achieved if all the fibers are aligned in the fiber-axis direction.
The properties, such as modulus and strength, decrease rapidly in directions
away from the fiber direction.
One of the outstanding characteristics of the rapidly increasing
technology of composite materials is the almost unlimited freedom of choice
that presents itself to the designer. Since not only the number of constituent in a
composite materials but also their distribution and orientation within a given
structural shape are subject to choice and can possibly lead to identical
performance characteristics, it is one of the foremost requirements for
developing the technology to also provide avenues for making this choice an
intelligent one.
1.3 Background
The most primitive composite materials were straw and mud combined to
form bricks for building construction. The ancient brick-making process can
still be seen on Egyptian tomb paintings in the Metropolitan Museum of Art.
The most advanced examples perform routinely on spacecraft in demanding
environments. The most visible applications pave our roadways in the form of
either steel and aggregate reinforced Portland cement or asphalt concrete. Those
composites closest to our personal hygiene form our shower stalls and bath tubs
made of fiberglass. Solid surface, imitation granite and cultured marble sinks
and counter tops are widely used to enhance our living experiences.

13. The recognition of the potential weight savings that can be achieved by
using the advanced composites, which in turn means reduced cost and greater
efficiency, was responsible for this growth in the technology of reinforcements,
matrices and fabrication of composites. If the first two decades saw the
improvements in the fabrication method, systematic study of properties and
fracture mechanics was at the focal point in the 60‘s. There has been an ever-
increasing demand for newer, stronger, stiffer and yet lighter- weight materials
in fields such as aerospace, transportation, automobile and construction sectors.
Composite materials are emerging chiefly in response to unprecedented
demands from technology due to rapidly advancing activities in aircrafts,
aerospace and automotive industries. These materials have low specific gravity
that makes their properties particularly superior in strength and modulus to
many traditional engineering materials such as metals. As a result of intensive
studies into the fundamental nature of materials and better understanding of
their structure property relationship, it has become possible to develop new
composite materials with improved physical and mechanical properties. These
new materials include high performance composites such as Polymer matrix
composites, Ceramic matrix composites and Metal matrix composites etc.
Continuous advancements have led to the use of composite materials in more
and more diversified applications. The importance of composites as engineering
materials is reflected by the fact that out of over 1600 engineering materials
available in the market today more than 200 are composite.

14. 1.4 Types of Composite Materials
Broadly, composite materials can be classified into three groups on the
basis of matrix material. They are:
a) Ceramic Matrix Composites (PMC)
b) Metal Matrix Composites (MMC)
c) Polymer Matrix Composites (CMC)
a) Ceramic Matrix Composites:
Ceramic fibers, such as alumina and SiC (Silicon Carbide) are
advantageous in very high temperature applications, and also where
environment attack is an issue. Since ceramics have poor properties in tension
and shear, most applications as reinforcement are in the particulate form (e.g.
zinc and calcium phosphate). Ceramic Matrix Composites (CMCs) used in very
high temperature environments, these materials use a ceramic as the matrix and
reinforce it with short fibers, or whiskers such as those made from silicon
carbide and boron nitride.
b) Metal Matrix Composites:
Metal Matrix Composites have many advantages over monolithic
metals like higher specific modulus, higher specific strength, better
properties at elevated temperatures, and lower coefficient of thermal
expansion. Because of these attributes metal matrix composites are

15. under consideration for wide range of applications viz. combustion chamber
nozzle (in rocket, space shuttle), housings, tubing, cables, heat exchangers,
structural members etc.
c) Polymer matrix Composites:
Most commonly used matrix materials are polymeric. The reasons for
this are twofold. In general the mechanical properties of polymers are
inadequate for many structural purposes. In particular their strength and
stiffness are low compared to metals and ceramics. These difficulties are
overcome by reinforcing other materials with polymers. Secondly the
processing of polymer matrix composites need not involve high pressure
and doesn‘t require high temperature. Also equipment required for
manufacturing polymer matrix composites are simpler. For this reason polymer
matrix composites developed rapidly and soon became popular for structural
applications. Polymer composites are used because overall properties of the
composites are superior to those of the individual polymers. They have a greater
modulus than the neat polymer but aren‘t as brittle as ceramics.
The most significant advantage of polymer matrix composites (PMCs)
derives from the fact that they are lightweight materials with high strength and
modulus values. The light weight of PMCs is due to the low specific gravities
of their constituents. Polymers used in PMCs have specific gravities between
0.9 and 1.5, and the reinforcing fibers have specific gravities between 1.4 and
2.6 (Mallick, 1993). Depending on the types of fiber and polymer used and their

16. relative volume fractions, the specific gravity of a PMC is between 1.2 and 2,
compared to 7.87 for steel and 2.7 for aluminum alloys. Because of their low
specific gravities, the strength-to-weight ratios of PMCs are comparatively
much higher than those of metals and their composites (Table 2.1). Although
the cost of PMCs can be higher than that of many metals, especially carbon or
boron fibers are used as reinforcements, their cost on a unit volume basis can
be competitive with that of the high performance metallic alloys used in the
aerospace industry.
A second advantage of PMCs is the design flexibility and the variety of
design options that can be exercised with them. Fibers in PMC can be
selectively placed or oriented to resist load in any direction, thus producing
directional strengths or moduli instead of equal strength or modulus in all
directions as in isotropic materials such as metals and unreinforced polymers.
Similarly, fiber type and orientation in a PMC can be controlled to produce a
variety of thermal properties such as the coefficient of thermal expansion.
PMCs can be combined with aluminum honeycomb, structural plastic foam, or
balsa wood to produce sandwich structures that are stiff and at the same time
lightweight. Two or more different types of fibers can be used to produce a
hybrid construction with high flexural stiffness and impact resistance (Mallick,
1997).
There are several other advantages of PMCs that make them desirable in
many applications. They have damping factors that are higher than those of
metals, which means that noise and vibrations are damped in PMC structures

17. more effectively than in metal structures. They also do not corrode. However,
depending on the nature of the matrix and fibers, their properties may be
affected by environmental factors such as elevated temperatures, moisture,
chemicals, and ultraviolet light.
Table 1.4 Comparative properties of metals and polymeric matrix compositesa (Mallick,
1993, p. 13)

18. 1.5 Reinforcements
The most common reinforcements are glass, carbon, aramid and boron
fibers. Typical fiber diameters range from 5 µm to 20 µm. The diameter of a
glass fiber is in the range of 5 to 25 µm, a carbon fiber is 5 to 8 µm, an aramid
fiber is 12.5 µm. Because of this thin diameter, the fiber is flexible and easily
conforms to various shapes. In general, fibers are made into strands for weaving
or winding operations. For delivery purposes, fibers are wound around a bobbin
and collectively called a ―roving‖. An untwisted bundle of carbon fibers is
called ―tow‖. In composites, the strength and stiffness are provided by the
fibers. The matrix gives rigidity to the structure and transfers the load the fibers.
Fibers for composite materials can come in many forms, from continuous
fibers to discontinuous fibers, long fibers to short fibers, organic fibers to
inorganic fibers. Some of the common types of reinforcements include:
• Continuous carbon tow, glass roving, aramid yarn
• Discontinuous chopped fibers
• Woven fabric
• Multidirectional fabric (stitched bonded for three dimensional properties)
• Stapled

19. 1.6 Types of Polymer Composites
Broadly, polymer composites can be classified into two groups on the
basis of reinforcing material. They are:
a) Fiber reinforced polymer (FRP)
b) Particle reinforced polymer (PRP)
a) Fiber Reinforced Composite
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. The fibers carry the loads along their longitudinal directions.
Sometimes, filler might be added to smooth the manufacturing process, impact
special properties to the composites, and / or reduce the product cost.
Common fiber reinforcing agents include asbestos, carbon / graphite
fibers, beryllium, beryllium carbide, beryllium oxide, molybdenum, aluminium
oxide, glass fibers, polyamide, bio fibers etc. Similarly common matrix
materials include epoxy, phenolic resin, polyester, polyurethane, vinyl ester etc.
Among these resin materials, polyester is most widely used. Epoxy, which has
higher adhesion and less shrinkage than polyesters, comes in second for its high
cost.

20. b) Particle Reinforced Composite
Particles used for reinforcing include ceramics and glasses such as small
mineral particles, metal particles such as aluminum and amorphous
materials, including polymers and carbon black. Particles are used to
increase the modules of the matrix and to decrease the ductility of the matrix.
Particles are also used to reduce the cost of the composites. Reinforcements
and matrices can be common, inexpensive materials and are easily processed.
Some of the useful properties of ceramics and glasses include high melting
temperature, low density, high strength, stiffness, wear resistance, and
corrosion resistance. Many ceramics are good electrical and thermal insulators.
Some ceramics have special properties; some ceramics are magnetic
materials; some are piezoelectric materials; and a few special ceramics are
even superconductors at very low temperatures. Ceramics and glasses have one
major drawback: they are brittle. An example of particle – reinforced
composites is an automobile tire, which has carbon black particles in a matrix
of poly-isobutylene elastomeric polymer.
Over the past few decades, we find that polymers have replaced
many of the conventional metals/materials in various applications. This is
possible because of the advantages polymers offer over conventional materials.
The most important advantages of using polymers are the ease of
processing, productivity and cost reduction. Polymer composites have
generated wide interest in various engineering fields, particularly in
aerospace applications. Research is underway worldwide to develop newer
composites with varied combinations of fibers and fillers so as to make them

21. useable under different operational conditions. In most of these applications,
the properties of polymers are modified using fillers and fibers to suit the high
strength/high modulus requirements. Fiber-reinforced polymers offer
advantages over other conventional materials when specific properties
are compared. These composites are finding applications in diverse fields from
appliances to spacecraft.
1.7 Bio Fiber Reinforced Composites
A bio-composite is a material formed by a matrix (resin) and a
reinforcement of bio fibers (usually derived from plants or cellulose). With
wide-ranging uses from environment-friendly biodegradable composites
to biomedical composites for drug/gene delivery, tissue engineering
applications and cosmetic orthodontics, they often mimic the structures of the
living materials involved in the process in addition to the strengthening
properties of the matrix that was used but still providing bio
compatibility. Bio-composites are characterized by the fact that the bolsters
(glass or carbon fiber or talc) are replaced by bio fiber (wood fibers, hemp, flax,
sisal, jute...). These bio/bio- fiber composites (bio-Composites) are
emerging as a viable alternative to glass-fiber reinforced composites
especially in automotive and building product applications. The combination of
bio-fibers such as kenaf, hemp, flax, jute, henequen, pineapple leaf fiber, and
sisal with polymer matrices from both nonrenewable and renewable resources
to produce composite materials that are competitive with synthetic composites
requires special attention. Bio fiber–reinforced polypropylene composites have
attained commercial attraction in automotive industries. Bio fiber-

22. polypropylene or bio fiber- polyester composites are not sufficiently eco-
friendly because of the petroleum-based source and the non-biodegradable
nature of the polymer matrix. Using bio fibers with polymers based on
renewable resources will allow many environmental issues to be solved. By
embedding bio-fibers with renewable resource–based biopolymers such as
cellulosic plastics; polylactides; starch plastics; polyhydroxyalkanoates
(bacterial polyesters); and soy-based plastics, the so-called green bio-
composites are continuously being developed.
1.8 Bio Fibers
Bio fibers have recently attracted the attention of scientists and
technologists because of the advantages that these fibers provide over
conventional reinforcement materials, and the development of bio fiber
composites has been a subject of interest for the past few years. These bio fibers
have low-cost with low density and high specific properties. These are
biodegradable and nonabrasive, unlike other reinforcing fibers. Also, they are
readily available and their specific properties are comparable to those of other
fibers used for reinforcements. However, certain drawbacks such as
incompatibility with the hydrophobic polymer matrix, the tendency to form
aggregates during processing, and poor resistance to moisture limit the potential
of bio-fibers to be used as reinforcement in polymers. Another important aspect
is the thermal stability of these fibers. These fibers are lingo-cellulosic and
consist of mainly lignin, hemi-cellulose, and cellulose. The cell walls of the
fibers undergo pyrolysis with increasing processing temperature and contribute
to char formation. These charred layers help to insulate the lingo- cellulosic

23. from further thermal degradation. Since most thermoplastics are processed at
high temperatures, the thermal stability of the fibers at processing temperatures
is important. Thus the key issues in development of bio reinforced composites
are
(i) Thermal stability of the fibers,
(ii) Surface adhesion characteristics of the fibers, and
(iii) Dispersion of the fibers in the case of thermoplastic composites.
1.9 Types of Bio Fibers
Bio fibers are grouped into three types: seed hair, bast fibers, and leaf fibers,
depending upon the source. Some examples are cotton (seed hairs), ramie, jute,
and flax (bast fibers), and sisal and abaca (leaf fibers). Of these fibers, jute,
ramie, flax, and sisal are the most commonly used fibers for polymer
composites. On the basis of the source which they are derived from bio fibers
can also be grouped as:
a) Fibers obtained from plant/vegetable. (cellulose: sisal, jute, abaca,
bagasse)
b) Fibers obtained from mineral. (minerals: asbestos)
c) Fibers derived from animal species. (sheep wool, goat hair, cashmere,
rabbit hair, angora fiber, horse hair, human hair)
d) Fibers from bird / aqueous species. (feather, sea snels etc.)

24. Numerous reports are available on the bio fiber composites. The research
works on development of bio/bio-fiber reinforced polymer composites have
been extensively reviewed also. Many researchers have been conducted to study
the mechanical properties, especially interfacial performances of the
composites based on bio fibers due to the poor interfacial bonding between the
hydrophilic bio fibers such as sisal, jute and palm fibers and the hydrophobic
polymer matrices.
1.10 Mechanical Properties of Bio Fibers
The tensile strength of glass fibers is substantially higher than that of
bio fibers even though the modulus is of the same order. However, when
the specific modulus of bio fibers (modulus/specific gravity) is considered,
the bio fibers show values that are comparable to or better than those of glass
fibers. These higher specific properties are one of the major advantages of using
bio fiber composites for applications wherein the desired properties also include
weight reduction.
Table 1.10 Mechanical Properties of Bio Fibers (Source Ref. 9).

25. 1.11 Matrix Resins
Thermosets Vs Thermoplastics
Nowadays both thermoplastic and thermosetting resins are used as
matrices for composites. Each type exhibits particular advantages and
disadvantages with respect to processability and service performance, as
illustrated in Table 1.11. Although a wide range of different chemistries exists
within each type, some general features can be distinguished, which have
determined their area of application.
Table 1.11a Property/process characteristics for thermoplastic and thermosetting matrix
systems.
Some of the basic properties of selected thermoset and thermoplastic
resins are shown in Table 1.11b and Table 1.11c, respectively.

26. Table 1.11b Typical unfilled thermosetting resin properties (Mazumdar, 2002, p. 48).
In general the crosslinked structure of thermosetting polymers provides
potential for higher stiffness and service temperatures than thermoplastics. The
upper limit of service temperature for advanced composites is most often
determined by the glass transition temperature.
On the other hand, toughness and elongation to break may be
considerably for thermoplastic resins. This may be a particular advantage in
applications where impact strength is a major requirement. Most high-
performance thermoplastics offer outstanding interlaminar fracture toughness
and acceptable post-impact compression response. This feature of thermoplastic
materials has been the major reason for their increased use in composite
structures.

27. Table 1.11c Typical unfilled thermoplastic resin properties (Mazumdar, 2002, p. 53).
From a processing viewpoint, the high melt viscosities of thermoplastics
generally create considerable difficulties during fiber wet-out and impregnation.
Thus, thermoplastic based composites generally require higher processing
temperatures and pressures to ensure sufficient flow during the final forming
process.
The higher processing temperatures and pressures needed for the forming
of thermoplastic-based composites generally impose stricter requirements on
the processing equipment, and more advanced engineering is needed
for tool construction. The higher processing temperatures may also induce
considerable difficulties in mismatch of thermal contraction between the matrix
and fibers during the processing cycle.
The longer relaxation times for thermosetting materials may be a
disadvantage, due to a reduced ability to relax process-induced internal stresses.
In anisotropic composites in particular, the potential of the polymer to relax

28. internal stress fields is important for the elimination of process-induced defects.
Such defects, in the form of voids, microcracking, fiber buckling, warpage, and
residual stresses may diminish the durability and long-term performance of the
composite.
Thermoplastic-based composites offer potential for lower conversion
costs from intermediate material forms into final end-use parts by process
automation. Furthermore, thermoplastics also offer the advantage of having
almost indefinite storage life, which facilitates the logistics of the
manufacturing procedure.
Finally, thermoplastics may be post formed and/or reprocessed by the
reapplication of heat and pressure, which gives a potential for recyclability. The
increased awareness, in these last years, about material Recyclability has
brought about a heightened interest in thermoplastic matrix composites,
especially in large volume areas such as the automobile industry.

29. Chapter 2
Literature Review

30. Chapter 2
Literature Review
During the last decades, particulates with fibers and fillers features so
called reinforce plastics are utilized to improve the physical and mechanical
properties of polymers and composites. Among the natural, inorganic and
organic fibers and fillers have been widely studied. In this study, keratin fiber
(human hair) use as organic natural fibers. Both filler and fiber are low cost,
higher thermal stability, excellent mechanical properties and abundance
provoked us to use these with plastics material. Natural fibers have received
much attention as reinforcing materials for polymers because of their
potentially high aspect ratio and unique intercalation / exfoliation
characteristics. Keratin fiber based composites has the lower density and good
mechanical properties as compare to material. Keratin fiber enhance mechanical
properties like impact, tensile, fracture etc, and reduce density.
2.1 Natural Bio-Fiber Reinforced Composites
Synthetic fibers such as glass, nylon, carbon, Kevlar and boron are
generally used to make composite materials for specific purposes even though
they are expensive and are non-renewable resources. This is because of their
very high specific strength properties which do not deteriorate appreciably with
time. On the other hand, there is a growing interest in the development of new
materials which enhance optimal utilization of natural resources, and
particularly, of renewable resources. The natural fibers like Keratin, cotton, jute

31. and sisal have also attracted the attention of scientists and technologists for
applications in consumer goods, low cost housing and civil structures where the
prohibitive cost of synthetic fibers restricts their use. These natural fiber
composites possess characteristic properties such as high electrical and impact
resistance, good thermal and acoustic insulating properties and high work of
fracture in addition to specific strengths comparable to synthetic fiber
reinforced polymer composites. Accordingly, manufacturing of high-
performance engineering materials from renewable resources has been pursued
by researchers across the world owning to renewable raw materials are
environmentally sound and do not cause health problem.
It is known that natural fibers are non-uniform with irregular cross
sections which make their structures quite unique and much different with man-
made fibers such as glass fibers, carbon fibers etc. Saheb and Jog have
presented a very elaborate and extensive review on the reported work on natural
fiber reinforced composites with special reference to the type of fibers, matrix
polymers, treatment of fibers and fiber-matrix interface. Many researchers have
been conducted to study the mechanical properties.
The matrix phase plays a crucial role in the performance of polymer
composites. Both thermosets and thermoplastics are attractive as matrix
materials for composites. In thermoset composites, formulation is complex
because a large number of components are involved such as base resin, curing
agents, catalysts, flowing agents, and hardeners. These composite materials are
chemically cured to a highly cross-linked, three-dimensional network structure.

32. These cross-linked structures are highly solvent resistant, tough, and creep
resistant. The fiber loading can be as high as 80% and because of the alignment
of fibers; the enhancement in the properties is remarkable. Thermoplastics offer
many advantages over thermoset polymers. One of the advantages of
thermoplastic matrix composites is their low processing costs. Another is design
flexibility and ease of molding complex parts. Simple methods such as
extrusion and injection molding are used for processing of these composites. In
thermoplastics most of the work reported so far deals with polymers such as
polyethylene, polypropylene, polystyrene, and poly (vinyl chloride). This is
mainly because the processing temperature is restricted to temperatures below
200ºC to avoid thermal degradation of the natural fibers. For thermoplastic
composites, the dispersion of the fibers in the composites is also an important
parameter to achieve consistency in the product.
Thermoplastic composites are flexible and tough and exhibit good
mechanical properties. However, the percentage of loading is limited by the
process ability of the composite. The fiber orientation in the composites is
random and accordingly the property modification is not as high as is
observed in thermoset composites. Properties of the fibers, the aspect ratio of
the fibers, and the fiber–matrix interface govern the properties of the
composites. The surface adhesion between the fiber and the polymer plays an
important role in the transmission of stress from matrix to the fiber and thus
contributes toward the performance of the composite. Another important aspect
is the thermal stability of these fibers. Since most thermoplastics are processed
at high temperatures, the thermal stability of the fibers at processing

33. temperatures is important. Thus the key issues in development of natural
reinforced composites are
(i) Thermal stability of the fibers,
(ii) Surface adhesion characteristics of the fibers,
(iii) Dispersion of the fibers in the case of thermoplastic composite.
2.2 Keratin fiber
Hair is composed of proteins, lipids, water, and small amounts of trace
elements. All proteins in animal and human bodies are built from permutations
of amino acid molecules in a polypeptide string. The polypeptide chains of
protein keratin are organized into filaments in hair cells. Hair is one of the most
difficult proteins to digest or solubilize. Among the most common dissolving
procedures for hair are acidic, alkaline, and enzymatic hydrolysis. For the
analysis of hair, the solid samples are transferred by solubilization via digestion
into a liquid phase. Small molecular solvents and molecules with hydrophobic
groups appear to have higher affinity for hair. A good solvent attacks the
disulfide bonds between cystine molecules and hydrates the hair shaft.
Consequently, the hair becomes a jelly-like mass.
2.3 Structure and Properties
Hair is a biological material consisting of polypeptide chains of keratin
arranged into filaments. In most mammals, hair increases the sensitivity of the
skin surface and forms an insulating and protective coat. Hair reduces heat loss

34. from the body and often provides camouflage. For humans, hair is important
only for personal adornment and display. In lower animals (e.g., insects), hairs
(whiskers) have a sensory function. Some stems, leaves, and plants also possess
hairs on their roots. Hair is a complex tissue and grows from the hair follicle
embedded in the inner layer (dermis) in the skin where the germination center is
formed by matrix cells that are in active build-up to layers of the hair shaft,
including the cuticle, cortex, and medulla. The cortex forms the bulk of the hair
shaft and is located immediately beneath the cuticle. The medulla is the
innermost region of hair and consists of scattered cells and hollow space.
Human hair is not homogeneous. In the outer layers of hair, the surface
composition may vary rapidly.
Figure 2.3 Structure of hair at various length-scales: (a) filament protein with globular end
group and alternating helical/linker sections; (b) coiled coil of filament proteins; (c)
intermediate filament with 16 coils; (d) filament embedded in matrix; (e) macrofibril; (f)
cortical call enclosed by cell-membrane complex; (g) cross-section of a hair fiber with cells,
nuclear remnants and pigment granules, enclosed by the cuticle.

35. The basic elemental composition of hair is:
49.0% carbon
14.5% nitrogen
30.0% oxygen
3.0% sulfur
Trace elements barium, calcium, chromium, copper, iron, manganese,
nickel, lead, titanium, zinc
Hair is a poor electrical and thermal conductor. Hair densities vary from
1.3 to 1.47 g/cm3. Hair diameters have a mean and standard deviation of 67.1 ±
12.0 μm. Protein keratin is made up of chains of amino acids, especially
arginine, cystine, and serine. As noted above, the softer keratins occur in the
external layers of skin, hair, wool, and feathers, while the harder types
constitute nails, claws, and hoofs.
The polypeptide chains of keratin are organized into filaments in hair
cells. Keratin gives a characteristic diffraction pattern. This pattern shows that
hair and wool possess a repeating structural unit along the long axis of the hair.
Consequently, the polypeptide chains in the fibrous proteins are coiled in some
regular way. Four kinds of fibrous proteins (keratins, collagen, and elastin) are
responsible for the structure of cells, tissues, and organisms. The chief
structural component of hair is protein keratin. Keratin in the cortex comprises
85% or more of the mass of the hair shaft. Cortical keratin is composed of two
types of structural proteins: matrix and fibrous. Matrix proteins have a high

36. sulfur content and contain polypeptides with a molecular weight of
approximately 10–28 kDa. The sulfur content of human hair is high compared
with other animal species. Fibrous proteins are embedded in matrix proteins and
are characterized by a low sulfur content.
Two types of proteins can be classified according to their
structure/shapes: fibrous and globular. The fibrous proteins are long and stringy
molecules with the polypeptide chains extended along one axis rather than
folded into a globular shape. In globular proteins, the polypeptide chains are
tightly folded into compact spherical or globular shapes. Nearly all enzymes,
antibodies, and blood transport proteins are globular proteins. The hydrophilic
or polar groups of globular proteins are exposed on the outer surface and
therefore are soluble in water, e.g., serum albumin.
2.4 Polymer Keratin based Fiber Composite
Polymer composites are widely used in areas of automotive, aerospace,
construction, and electronic industries because of their improved mechanical
(e.g., stiffness, strength) and physical properties over pure polymers. These
composites are made using micron-sized particulates and long fibers to
reinforce the weak polymer matrices. In recent years polymer composites have
drawn a great deal of interest because of a high potential of achieving property
improvement by a small addition of nanoparticles in the polymer matrices.
Furthermore, this significant improvement in variety of properties is achieved
without sacrificing the lightweight of polymer matrices.

37. Essentially, this technology can be used in any application where
improving polymer properties would be of value – either by improving existing
materials or by reducing the amount of material required to match current
physical capabilities.
Future developments include:
• Adapting the technology for different types of polymers;
• Biodegradable composites;
• Self-healing materials; and
• Potential use for electrical purposes. Many of the electrical and conductive
properties of keratin have not been explored in detail but our work so far
indicates.

38. Chapter 3
Materials and Methods

39. Chapter 3
Materials and Methods
This chapter describes the materials and methods used for the processing
of the composites under this investigation.
3.1 Matrix material
3.1.1 Low-Density Polyethylene (LDPE)
LDPE is a semi-rigid, translucent material, and was the first of the
polyethylene to be developed. It is primarily used at ‗normal‘ operating
temperatures. Its qualities include toughness, flexibility, resistance to chemicals
and weather, and low water absorption. It is easily processed by most methods
and has a low cost. It is also resistant to organic solvents at room temperature.
Its use is not advisable in situations where extreme temperatures are found. It is
a corrosion-resistant, low density extruded material that provides low moisture
permeability. LDPE has a fairly low working temperature, soft surface, and low
tensile strength. It is an excellent material where corrosion resistance is an
important factor, but stiffness, high temperature, and structural strength are not
important considerations.
LDPE resins are re-emerging as a valuable product family, combining
superior clarity with a stiffness and density favoured by converters for down
gauging. Ease of processing beyond most linear low-density PE (LLDPE)

40. resins, combined with improved product performance, continues to give cost-
competitive solutions to converters in a wide variety of fi lm applications.
These range from complex food packaging structures to shopping bags, coated
paperboards, liners, overwraps, consumer bags, heavy-duty sacks, clarity shrink
and collation films, lamination films, agricultural films, extrusion coatings, caps
and closures, and a variety of durable products such as power cables and toys.
In packaging applications Dow LDPE resins offer excellent aesthetics,
printability, strength, tear resistance, and elasticity. In cost-sensitive health and
hygiene markets LDPE resins can improve processing efficiencies, and can be
used for wire, cable, pipes, and other goods.
LDPE is lightweight and formable, has a high impact resistance and
excellent electrical properties, and is machinable and weldable. LDPE can be
processed by all conventional methods: hot gas welded fusion and butt welded,
ultrasonically sealed, die cut, machined with wood- or metal-working tools,
vacuum formed, and thermoformed. The long side-chain branching of the
LDPE molecules produces a more amorphous polymer having a lower melting
point and higher clarity compared to LLDPE. LDPE is also differentiated from
LLDPE by poorer physical properties as regards tensile strength, puncture and
tear resistance, and elongation. LDPE has very good flow behaviour and
excellent resistance to chemicals. It is flexible and tough at low temperatures,
transparent in thin films, and has very good environmental stress crack
resistance (ESCR). UV-stabilized LDPE is used in agricultural/building
components and sheeting film.

41. The disadvantages of LDPE are its low strength, stiffness, and maximum
operating temperature, flammability, poor UV resistance, high gas permeability
(particularly CO2), and susceptibility to environmental stress cracking.
3.1.2 High-Density Polyethylene (HDPE)
HDPE is more rigid and harder than lower density materials with a
molecular weight below 300,000 g/mol. It also has a high tensile strength and
has high compressive strength.
The extremely high molecular weight of HDPE combined with its very
low coefficient of friction produces an excellent abrasion-resistant product
which is resistant to gouging, scuffing, and scraping. HDPE has exceptional
impact strength, being one of the best impact-resistant thermoplastics available,
and has excellent machinability and self-lubricating characteristics. Its
properties are maintained even at extremely low temperatures. HDPE has stress
cracking resistance and very good chemical resistance to corrosives (with the
exception of strong oxidizing acids at elevated temperatures). Certain
hydrocarbons cause only a light surface swelling at moderate temperature.
Moisture and water (including saltwater) have no affect on HDPE. It can be
used in freshwater and saltwater immersion applications. HDPE can be hot gas
welded, fusion and butt welded, ultrasonically sealed, die cut, machined with
wood- or metalworking tools, vacuum formed, and thermoformed.

42. Representing the largest portion of PE applications, HDPE offers
excellent impact resistance, is of low weight, has low moisture absorption, and
has high tensile strength. HDPE is stronger and stiffer but its impact strength is
not as good at low temperatures. It is also more prone to warpage due to its
higher crystallinity, which makes it very sensitive to differential cooling rates
across the walls of rotomoulded products. HDPE also has higher shrinkage than
LDPE.
HDPE does have certain disadvantages. It is susceptible to stress
cracking, has lower stiffness compared to polypropylene (PP), high mold
shrinkage, and poor UV resistance. It is also available in a UV-stabilized form
that has better UV resistance, but the tensile strength and elongation at break
are reduced compared with unmodified HDPE. HDPE may give off dangerous
fumes if strongly heated and dense smoke is formed when it burns. Dust can be
an irritant to the eyes, skin, and respiratory system.
3.2 Composite Processing
3.2.1 Compression Molding
Compression molding is a method of molding in which the molding
material, generally preheated, is first placed in an open, heated mold cavity. The
mold is closed with a top force or plug member, pressure is applied to force the
material into contact with all mold areas, while heat and pressure are
maintained until the molding material has cured. The process employs
thermosetting resins in a partially cured stage, either in the form of granules,

43. putty-like masses, or preforms. Compression molding is a high-volume, high-
pressure method suitable for molding complex, high-strength fiberglass
reinforcements. Advanced composite thermoplastics can also be compression
molded with unidirectional tapes, woven fabrics, randomly oriented fiber mat or
chopped strand. The advantage of compression molding is its ability to mold
large, fairly intricate parts. Also, it is one of the lowest cost molding methods.
However, compression molding often provides poor product consistency
and difficulty in controlling flashing, and it is not suitable for some types of
parts. Fewer knit lines are produced and a smaller amount of fiber-length
degradation is noticeable when compared to injection molding. Compression-
molding is also suitable for ultra-large basic shape production in sizes beyond
the capacity of extrusion techniques.

44. Chapter 4
Experimental Details & Result

45. Chapter 4
Experimental Details & Result
4.1 Tensile Test of 0.5 mm Thick LDPE Sheet prepared by
Reinforcing Keratin Fiber (Human Hair)
Testing standard-ASTM D 882
Significance and Use
Tensile properties determined by this test method are of value for the
identification and characterization of materials for control and specification
purposes. Tensile properties can vary with specimen thickness, method of
preparation, speed of testing, type of grips used, and manner of measuring
extension. Consequently, where precise comparative results are desired, these
factors must be carefully controlled. This test method shall be used for referee
purposes, unless otherwise indicated in particular material specifications. For
many materials, there can be a specification that requires the use of this test
method, but with some procedural modifications that take precedence when
adhering to the specification.

46. Tensile properties can be utilized to provide data for research and
development and engineering design as well as quality control and
specification. However, data from such tests cannot be considered significant
for applications differing widely from the load-time scale of the test employed.
The tensile modulus of elasticity is an index of the stiffness of thin plastic
sheeting. The reproducibility of test results is good when precise control is
maintained over all test conditions. When different materials are being
compared for stiffness, specimens of identical dimensions must be employed.
The Tensile Energy to Break (TEB) is the total energy absorbed per unit
volume of the specimen up to the point of rupture. In some texts this property
has been referred to as toughness. It is used to evaluate materials that are
subjected to heavy abuse or that can stall web transport equipment in the event
of a machine malfunction in end-use applications. However, the rate of strain,
specimen parameters, and especially flaws can cause large variations in the
results. In that sense, caution is advised in utilizing TEB test results for end-use
design applications. Materials that fail by tearing give anomalous data which
cannot be compared with those from normal failure.

47. Scope
1.1 This test method covers the determination of tensile properties of Plastics
in the form of thin sheeting and films (less than 1.0 mm (0.04 in.) in thickness).
Note 1—Film is defined in Terminology D883 as an optional term for sheeting
having a nominal thickness no greater than 0.25 mm (0.010 in.).
Note 2—Tensile properties of plastics 1.0 mm (0.04 in.) or greater in thickness
shall be determined according to Test Method D638.
1.2 This test method can be used to test all plastics within the thickness range
described and the capacity of the machine employed.
1.3 Specimen extension can be measured by grip separation, extension
indicators, or displacement of gage marks.
1.4 The procedure for determining the tensile modulus of elasticity is
included at one strain rate.
Note 3-The modulus determination is generally based on the use of grip
separation as a measure of extension; however, the desirability of using
extensometers, is recognized and provision for the use of such instrumentation
is incorporated in the procedure.
1.5 Test data obtained by this test method is relevant and appropriate for use
in engineering design.
1.6 The values stated in SI units are to be regarded as the standard. The
values in parentheses are provided for information only.
1.7 This standard does not purport to address all of the safety concerns, if
any, associated with its use. It is the responsibility of the user of this standard to

48. establish appropriate safety and health practices and determine the applicability
of regulatory limitations prior to use.
Note 4—this test method is similar to ISO 527-3, but is not considered
technically equivalent. ISO 527-3 allows for additional specimen
configurations, specifies different test speeds, and requires an extensometer or
gage marks on the specimen.
Sample Size for the test sample:
There were four samples out of which three samples are being prepared
by reinforcing hair and one sample is a standard sample for comparison of
tensile and other properties:
S. No. Thickness (mm) Width (mm) Length (mm)
1 0.35 25 150
2 0.24 25 150
3 0.32 25 150
4 0.22 25 150
Specimen Preparation
The specimen is prepared by laying the hair one by one into the plastic
sheet of LDPE. There is no particular gap between two hairs. The hairs are
being arranged in the longitudinal direction. After laying the hair the next step
is to compress the sheet in pneumatic compression molding machine. The

49. temperature which is set is 180˚C. The sheet is compressed into the machine for
ten minutes and then taken out and the samples of prescribed dimensions are cut
by the cutter.
Machine Used
1. Compression Molding
2. Cutter
Pictures of prepared samples are given below
Sample 1
Fig. 4.1a

50. Sample 2
Fig. 4.1b
Sample 3
Fig. 4.1c

51. Sample 4
fig. 4.1d
Procedure Used
The samples are tested in universal testing machine. Two marks of each
50 mm made from both side for gripping the specimen in UTM. The specimens
are then attached in the UTM machine for testing. The operating speed of
machine is 50mm/min .by minutely viewing it can be seen that the load is first
transferred to the keratin (human hair) fiber and then to the sheet. Since these
hairs are embedded into the sheet the hair break in the alignments direction and
then the sheet got stretched.

52. Data
The following calculations can be made from tensile test results
1. Tensile strength (at yield and at break)
2. Tensile modulus
3. Strain
4. Elongation and percent elongation at yield
5. Elongation and percent elongation at break
The results of the tested samples are as follows
S.
No.
Max.
Load
Tensile
Strength
(PSi)
Modulus
(Automatic)
(MPa)
Tensile at
Max.
Erosion
(%)
Tensile
strain at
Max.
Load (%)
Speed
(mm/min)
1. 68.23 7.8 76.41 366.31 43.49996 50
2. 40.88 6.81 145.84 87.83985 16.33353 50
3. 82.31 10.29 105.66 160.5266 44.16673 50
4. 49.27 8.96 109.24 158.21327 62.16672 50

55. S. No. Data Avg. values of
Hair reinforced
sheet
Avg. values of
sheet w/o Hair
1. Max. Load (N) 63.80 49.27
2. Tensile Strength
(PSi)
8.3 8.96
3. Modulus 109.30 109.24
4. Tensile Strain at
Max. Extension
(%)
204.80 158.213
5. Tensile Strain at
Max. Load (%)
34.66 62.1672
6. Speed 50 50
Thus from the compared data it is clear that after reinforcing the keratin
fiber of length 15 mm, the values of load, modulus, tensile strain at maximum
extension got increased by a considerable amount. And the load is first
transferred to the hair which break at some stage of stretching of the sheet and
the main load is transferred to the sheet after breaking of the hairs.

56. 4.2 Tensile Test of the Plastic Sheet (3-4 mm) Thick made from
HDPE Material reinforced with disintegrated Human Hair
Standard- ASTM D638
Scope
Tensile tests measure the force required to break a specimen and the
extent to which the specimen stretches or elongates to that breaking point.
Tensile tests produce a stress-strain diagram, which is used to determine tensile
modulus. The data is often used to specify a material, to design parts to
withstand application force and as a quality control check of materials. Since
the physical properties of many materials (especially thermoplastics) can vary
depending on ambient temperature, it is sometimes appropriate to test materials
at temperatures that simulate the intended end use environment.
Test Procedure
Specimens are placed in the grips of the Instron at a specified grip
separation and pulled until failure. For ASTM D638 the test speed is
determined by the material specification. For ISO 527 the test speed is typically
5 or 50mm/min for measuring strength and elongation and 1mm/min for
measuring modulus. An extensometer is used to determine elongation and
tensile modulus.

57. Elevated or Reduced Temperature Test Procedure
A thermal chamber is installed on the Instron universal test machine. The
chamber is designed to allow the test mounts from the base and crosshead of the
Instron to pass through the top and bottom of the chamber. Standard test
fixtures are installed inside the chamber, and testing is conducted inside the
controlled thermal environment the same as it would be at ambient temperature.
The chamber has internal electric heaters for elevated temperatures and uses
external carbon dioxide gas as a coolant for reduced temperatures. The size of
the chamber places a limitation on the maximum elongation that can be
reached, and extensometers are generally limited to no more than 200° C.
Specimen Size
The most common specimen for ASTM D638 is a Type I tensile bar.
Whose dimensions are as per standard, and is being prepared by punch die.
Data
The following calculations can be made from tensile test results:
1. Tensile Strength (at yield and at break)
2. Tensile Modulus
3. Strain
4. Elongation and % Elongation at yield
5. Elongation and % Elongation at break

58. Machine used in the Preparation of Sample
The machine used in the preparation of material for specimen is two toll
mill .the material preparation conditions are given below:
1. Two Roll Mill
Front roll mill temp-180˚C
Load - 1.4 rpm
S .V- 15.0
P.V- 15.0
Rear roll mill temp- 200˚C
Load - 1.5 rpm
S.V-12.0
P.V- 12.0
Nip Gap (roll gap): 0.58 mm
1: Extensometers
2: Instron Universal Tester
Procedure
A fixed amount of material is taken (200 gm) and taken in two roll mill
in order to melt the material and also to disperse the hair of size about 1mm.
The conditions used or employed are given above.

59. S. No. Wt. of HDPE (gm) % of Hair
1. 200 1
2. 200 0
After proper dispersion of disintegrated hair the material is being ready
for preparing for the sheet. The sheet is prepared by compression molding at a
temperature of 180ºC. When the sheet is prepared then the final testing sample
are cut with the help of punch and die assembly.
Test Details
Results of Tensile Test of Hair Reinforced HDPE Material
S.
No.
Max.
Load
(N)
Tensile
Strength
(MPa)
Modulus
(Automatic)
(MPa)
Tensile
Strain at
Max.
Extension
(%)
Tensile
Strain at
Max.
Load
(%)
Speed
(mm/min)
Tensile
Stress at
Yield
(Zero
slope)
(MPa)
1. 515.10 22.36 449.56 688.85932 14.66589 50 22.35693
2. 481.79 24.11 472.22 170.04633 14.33346 50 24.11366
3. 693.49 24.08 414.21 160.006971 16.66668 50 24.07948
4. 686.55 23.69 417.11 60.31994 16.33353 50 22.35693

60. Graphs for the Tests
Sample 1
Sample 2

61. Sample 3
Sample 4

62. The sample number 1 & 2 are the samples which are hair reinforced and
sample number 3&4 are the samples which are prepared by pure HDPE
material. The thicknesses of samples are given below:
Sample 1. 3.84 mm
Sample 2. 3.33 mm
Sample 3. 4.805 mm
Sample 4. 4.83 mm
Comparission of Values
S. NO. Data Avg. Value for
Sample w/o Hair
Avg. Value for
Sample with
Hair
1. Maximum Load (N) 498.44 690.02
2. Tensile Strength (MPa) 23.235 23.885
3. Modulus (Automatic) (MPa) 460.89 415.66
4. Tensile strain at Maximum
Extension (%)
429.44 110.16
5. Tensile strain at Maximum
Load (%)
14.49967 16.50554
6. Speed (mm/min) 50 50
7. Tensile stress at Yield
(Zero Slope) (MPa)
23.235 23.250

63. Thus from above compared results it is clear that the value of maximum
load, tensile strength and tensile strain at maximum load got increased in the
case of hair reinforced composite with HDPE material. While the value of
tensile stress at yield remained almost constant and the value of modulus and
tensile strain at maximum extension got decreased in the case of reinforced hair
composite.

64. 4.3 Flexural Test of Reinforced Sheet of HDPE Material
Standard- ASTM D790
Scope
The flexural test measures the force required to bend a beam under three
point loading conditions. The data is often used to select materials for parts that
will support loads without flexing. Flexural modulus is used as an indication of
a material‘s stiffness when flexed. Since the physical properties of many
materials (especially thermoplastics) can vary depending on ambient
temperature, it is sometimes appropriate to test materials at temperatures that
simulate the intended end use environment.
Test Procedure
Most commonly the specimen lies on a support span and the load is
applied to the center by the loading nose producing three point bending at a
specified rate. The parameters for this test are the support span, the speed of the
loading, and the maximum deflection for the test. These parameters are based
on the test specimen thickness and are defined differently by ASTM and ISO.
For ASTM D790, the test is stopped when the specimen reaches 5% deflection
or the specimen breaks before 5%. For ISO 178, the test is stopped when the
specimen breaks. Of the specimen does not break, the test is continued as far a
possible and the stress at 3.5% (conventional deflection) is reported.

65. Elevated or Reduced Temperature Test Procedure
A thermal chamber is installed on the universal test machine. The
chamber is designed to allow the test mounts from the base and crosshead of the
universal tester to pass through the top and bottom of the chamber. Standard
test fixtures are installed inside the chamber, and testing is conducted inside the
controlled thermal environment the same as it would be at ambient temperature.
The chamber has internal electric heaters for elevated temperatures and uses
external carbon dioxide gas as a coolant for reduced temperatures.
Specimen Size
A variety of specimen shapes can be used for this test, but the most
commonly used specimen size for ASTM is 3.2 mm x 12.7 mm x 125 mm
(0.125" x 0.5" x 5.0") and for ISO is 10 mm x 4 mm x 80 mm.
Data
Flexural stress at yield, flexural strain at yield, flexural stress at break,
flexural strain at break, flexural stress at 3.5% (ISO) or 5.0% (ASTM)
deflection, flexural modulus. Stress/Strain curves and raw data can be provided.

66. Equipment Used
1. Universal Tester
2. Flexural test fixtures
Procedure for Sample Preparation
The sheet which is used for preparing the tensile test is also used for
preparing the flexural test sample.
A fixed amount of material is taken (200 gm) and taken in two roll mill
in order to melt the material and also to disperse the hair of size about 1mm.the
conditions used or employed are given above.
S. No. Wt. of HDPE (gm) % of Hair
1. 200 1
2. 200 0
After proper dispersion of disintegrated hair the material is being ready
for preparing for the sheet. The sheet is prepared by compression molding at a
temperature of 180ºC. When the sheet is prepared then the final testing sample
are cut with the help of punch and die assembly.

67. Test Details
S. No. Max.
Flexural
Load
Modulus (Automatic) (MPa) Flexural Stress
at Max. Flexure
Load (MPa)
1. 52.15 737.56835 20.41042
2. 53.45 756.14239 20.91792
3. 37.91 861.05640 21.38298
4. 41.63 877.53622 23.48303

68. Graphs of Flexural Test
Sample 1
Sample 2

69. Sample 3
Sample 4

70. The sample number 1 & 2 are the samples which are hair reinforced and
sample number 3&4 are the samples which are prepared by pure hdpe material.
The thicknesses of samples are given below:
Sample 1. 4.83 mm
Sample 2. 4.68 mm
Sample 3. 3.35 mm
Sample 4. 3.40 mm
The length and width of the sample are as per the standard.
Comparison of Values
S. No. Data l Avg. Value for w/o
Hair HDPE
Material
Avg. Value for w/o
Hair Reinforced
HDPE Material
1. Max. Flexure
Load (N)
39.77 52.80
2. Modulus
(Automatic)
(MPa)
869.29631 746.85537
3. Flexure Stress at
Max. Flexure
Load (MPa)
22.43305 20.66417

71. From the above results it can be seen that the maximum flexure load
wear by the virgin material i.e. HDPE is 39.77 and by the composite prepared
by reinforcing 1% keratin fiber(human hair) material is 52.80.thus it is clear
that the flexure load wearing capacity of reinforced material is more as
compared to virgin material.
The value for modulus of the virgin material is more than that of
reinforced composite and also the flexure stress at maximum flexure load is
also more than that of with hair composite.

72. Chapter 5
CONCLUSIONS

73. Chapter 5
CONCLUSIONS
5.1 Conclusions
The experimental investigation and statistical analysis on Keratin fiber
reinforced HDPE matrix composites has led to the following conclusions:
Keratin fibers (Human Hair) bears high aspect ratio and hence are good
reinforcement material for fabrication of randomly oriented short fiber
reinforced HDPE composites. By incorporating Keratin fiber, density of the
composites decreases and possess very low amount of porosity. However,
Flexural strength and hardness of these composite increases with weight % of
feather fiber, but not aggressively.

74. 5.2 Recommendation for Future Work
The present work leaves a wide scope for future investigators to explore
many other aspects of bio-fiber reinforced polymer composites. Some
recommendations for future areas of research include:
1. To increase mechanical strength of these composites for their use in
different sectors can be studied.
2. Environmental study of Keratin fiber reinforced polymer composites i.e.
the effect of different environmental conditions like alkaline medium,
acidic medium, freezing temperature etc. on the properties and/or
degradation of these composites is to be evaluated.
3. Possible use of other fibers/flakes obtained from bio-wastes in the
development of new composites.
4. Other polymers can be tried as the matrix material for fabrication of
Human Hair reinforced composites.

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