(updated) Report - Batch 4.pdf

EXPERIMENTAL INVESTIGATION OF HYBRID COMPOSITES LACED WITH LEATHER WASTE, BEACH SAND AND USED TEA POWDER A PROJECT REPORT

Submitted by

JAGADISH KUMAR M.

412815114061

JEGAN M.

412815114062

MADHAVA PANDIYAN C.N.

412815114076

MOHAMED SAMEER

412815114080

in partial fulfillment for the award of degree of

BACHELOR OF ENGINEERING in MECHANICAL ENGINEERING

VALLIAMMAI ENGINEERING COLLEGE KATTANKULATHUR, CHENNAI - 603 204

ANNA UNIVERSITY: CHENNAI 600 025 APRIL – 2019

BONAFIDE CERTIFICATE This is to certify that the project entitled “Experimental investigation of hybrid composites laced with leather waste, beach sand and used tea powder” is a bonafide work carried out by the following students whose names are given below

JAGADISH KUMAR M. JEGAN M. MADHAVA PANDIYAN C.N. MOHAMED SAMEER

412815114061 412815114062 412815114076 412815114080

who successfully completed the project work under my direct supervision.

SIGNATURE

SIGNATURE

Dr. K. SIVAKUMAR, M.E, Ph.D,

Mr . S. SIVALINGAM, M.E,

HEAD OF THE DEPARTMENT

SUPERVISOR

Mechanical Engineering

ASSISTANT PROFESSOR

Valliammai Engineering College

Mechanical Engineering

Kattankulathur, Chennai - 603 204

Valliammai Engineering College Kattankulathur, Chennai - 603 204

Submitted for the Viva voce examination held on………………

Internal Examiner

External Examiner ii

ACKNOWLEDGEMENT

I

sincerely express my deep sense of gratitude

Pachamuthu, chairman and

to Dr. T.R.

Dr. T.P. Ganesan,

Director

of

Valliammai Enginering College for providing all necessary facilities to earn knowledge from the institution. I convey my sincere thanks to the principal Dr. B. Chidambararajan, M.E., Ph.D., Valliammai Engineering College for his encouragement and support extended throughout the course of our study. We wish to express our profound thanks with gratitude to our head of the department Dr. K. SIVAKUMAR, M.E., Ph.D., for providing us to do this project.

We take this opportunity to express our deep sense of gratitude and indebtedness to our Project Supervisor Mr. S. SIVALINGAM, M.E, for his

excellent

guidance,

continuous

motivation,

and

constant

encouragements given to us to do this project successfully.

We bestow our sincere thanks to our Project Coordinator Mr. P. RAMU, M.E, without whose invaluable guidance, patient and constant encouragement, anything would not have been materialized.

Lastly we would like to thank all our friends living in different parts of the world & all our family members for their moral and financial support during the tenure of our project.

iii

ABSTRACT

The leather industry is one of the prominent growing industries in the world. This industry places a footprint on huge amount of wastes as pollutants. This project describes a new approach of usage of leather used tea powder and beach sand. Beach sand comprises mainly of silica which can be a versatile material as fillers in composites due to its high modulus, stiffness and chemical inertness. This project is aimed to study the various properties of the mentioned materials, test their use in the preparation of hybrid composites through hand layup method. The flexural, bending, hardness and impact tests of the specimens are tested and their results compared. It was found that Sample 1 (4.1 % LW, 15.07 % GF) was found to be the best, followed by the Sample 3 (18 % LW, 21.7 % STL, 9.9% GF) and Sample 2 (23.5 % LW, 54.5 % S).

iv

TABLE OF CONTENTS CHAPTER No.

1

TITLE

PAGE No.

ABSTRACT

iv

LIST OF TABLES

viii

LIST OF FIGURES

ix

LIST OF SYMBOLS

xi

INTRODUCTION

1

1.1 Introduction

1

1.2 What composites are

1

1.3 Why composites

2

1.4 Classification of composite material

2

1.5 Phases of composite materials

4

1.5.1 Matrix Phase

4

1.5.1.1 Polymer matrix composites

5

1.5.1.2 Metal matrix composites

6

1.5.1.3 Ceramic matrix composites

7

1.5.2 Matrix selection 1.5.2.1 Functions of a matrix 1.5.3 Reinforcement phase

7 8 8

1.5.3.1 Fibre reinforced composites

9

1.5.3.2 Laminar composites

10

1.5.3.3 Particulate reinforced composites

10

1.5.3.4 Leather Composites

11

1.5.4 Advantages of composites

12

2

3

LITERATURE REVIEW

13

2.1 Overview

13

COMPOSITE MATERIALS

17

3.1 Leather waste

17

3.1.1 Leather

17

3.1.2 Tanning methods

17

3.1.3 Leather grades

19

3.1.4 Leather waste

21

3.2 Epoxy resin LY 556 and hardener HY 951

21

3.2.1 Introduction

21

3.2.2 Epoxy Resin LY 556

22

3.2.3 Hardener HY 951

23

3.3 Beach Sand

25

3.4 Tea waste

26

3.5 Glass fibre

27

4

PROJECT WORK PLAN

28

5

EXPERIMENTAL PROCEDURE

29

6

5.1 Mould making

29

5.2 Composite preparation

31

5.3 The tests

35

5.3.1 Flexural Test

35

5.3.2 Tensile Test

36

5.3.3 Impact Test

37

5.4.4 Hardness Test

38

CALCULATIONS

39

7

RESULTS AND DISCUSSION

41

7.1 Flexural Test

41

7.2 Tensile Test

46

7.3 Impact Test

51

7.4 Hardness Test

53

7.5 Overall Comparison

55

8

COST ESTIMATION

56

9

CONCLUSION

57

10

APPENDIX

58

11

REFERENCES

65

vii

LIST OF TABLES

TABLE NUMBER

CONTENT

PAGE NUMBER

3.1.4

Properties of leather waste

21

3.2.2

Properties of epoxy LY 556

23

Properties of hardener HY 951

24

3.3

Properties of beach sand

26

3.4

Properties of tea waste

26

3.5

Properties of glass fibre

27

6.1

Specification of slabs

39

6.2

Tabulation of results

40

7.3.1

Impact Test Values

52

7.4.1

Hardness test values

54

7.5.1

The observed values of the specimens

55

Cost Estimation table

56

3.2.3

10.1

viii

LIST OF FIGURES

FIGURE NUMBER 1.4.1

CONTENT

PAGE NUMBER

First level of composite classification

3

First classification of matrix phase

5

Second classification of matrix phase

6

5.1.1

Demarcating Process

29

5.1.2

Cutting Process

30

5.1.3

The prepared mould

31

5.2.1

Laying the filler materials

32

5.2.2

Applying resin onto filler material

32

1.4.2

1.4.3

5.2.3

Weight placed onto apparatus

5.2.4

One of the prepared composites

34

The prepared composites for hardness testing

34

5.3.1

Flexural Test Machine

36

5.3.2

Tensile Testing Machine

37

7.1.1

Specimen dimensions for flexural/bending test (mm)

41

5.2.5

33

7.1.2

The prepared samples (after testing)

41

7.1.3

Flexural Test Graph

45

7.2.1

Specimen dimensions for tensile test (mm)

46

The prepared samples (after testing)

46

7.2.3

Tensile Test Graph

50

7.3.1

Specimen dimensions for Izod test

51

7.2.2

7.3.2

The prepared samples (after testing)

51

7.3.3

Impact Test Graph

52

7.4.1

Shore D hardness test

53

7.4.3

Hardness test graph

54

7.5.1

Overall Values Graph

55

x

LIST OF SYMBOLS

SERIAL NUMBER

SYMBOL`

1

C

2

WLB

3

ABBREVIATION

PAGE NUMBER

Degree Celsius

6

Waste Leather Base

14

BC

Before Christ

17

4

STL

Spent Tea Leaf

26

5

ASTM

American Society for Testing and Materials

35

6

Dia

Diameter

39

7

LW

Leather Waste

57

8

S

Sand

57

9

GF

Glass Fibre

57

xi

CHAPTER 1 INTRODUCTION 1.1 INTRODUCTION In today’s world of modern engineering, we find a wide variety of materials that are being used to manufacture and produce articles that we use in our day-to-day lives. These materials have become integral, in a way akin to food, air and water; as the human body needs them in order to survive, similarly the industries as well as ourselves are dependent on these materials for satiating the needs of the day. Many materials such as steel, plastics, etc. are some of the most commonly used engineering materials; however, the modern engineering industry is on the lookout for new recruits of materials that are lighter and much stronger than the conventional engineering materials. It is for this reason that the birth of composite materials was very much inevitable. Composites have become one of the aspiring and promising engineering materials that could replace conventional engineering materials in the days to come. The composites industry is an exciting industry to work in because new materials, processes and applications are being developed all the time – like using hybrid virgin and recycled fibres, faster and more automated manufacturing. The global composites materials market is growing at about 5% per year, with carbon fibre demand growing at 12% per year. 1.2 WHAT COMPOSITES ARE Composite material is a material composed of two or more distinct phases (matrix phase and reinforcing phase) and having bulk properties significantly different from those of any of the constituents. Many of the common materials (metals, alloys, doped ceramics and polymers mixed with additives) also have a

1

small amount of dispersed phases in their structures, however they are not considered as composite materials since their properties are similar to those of their base constituents (physical property of steel are similar to those of pure iron) . Favorable properties of composites materials are high stiffness and high strength, low density, high temperature stability, high electrical and thermal conductivity, adjustable coefficient of thermal expansion, corrosion resistance, improved wear resistance etc. 1.3 WHY COMPOSITES These are the criteria that are required to satisfy the uses of composites:  Weight reduction in manufacturing of components and parts  Resistance to thermal and chemical interactions  Ease of machinability while retaining their superior properties Composites are able to meet the various design requirements with significant weight savings as well as high strength-to-weight ratio as compared to conventional materials. 1.4 CLASSIFICATION OF COMPOSITE MATERIALS Composite materials are commonly classified at following two distinct levels: • The first level of classification is usually made with respect to the matrix constituent. The major composite classes include Organic Matrix Composites (OMCs), Metal Matrix Composites (MMCs) and Ceramic Matrix Composites (CMCs). The term organic matrix composite is generally assumed to include two classes of composites, namely Polymer Matrix Composites (PMCs) and carbon matrix composites commonly referred to as carbon-carbon composites.

2

Fig 1.4.1 First level of composite classification

• The second level of classification refers to the reinforcement form - fibre reinforced composites, laminar composites and particulate composites. Fibre Reinforced composites (FRP) can be further divided into those containing discontinuous or continuous fibres. • Fibre Reinforced Composites are composed of fibres embedded in matrix material. Such a composite is considered to be a discontinuous fibre or short fibre composite if its properties vary with fibre length. • Laminar Composites are composed of layers of materials held together by matrix. Sandwich structures fall under this category. • Particulate Composites are composed of particles distributed or embedded in a matrix body. The particles may be flakes or in powder form. Concrete and wood particle boards are examples of this category.

3

1.5 PHASES OF COMPOSITE MATERIALS Composites mainly constitute of two phases:  Matrix phase  Reinforcement phase 1.5.1 MATRIX PHASE The matrix is the monolithic material into which the reinforcement is embedded, and is completely continuous. This means that there is a path through the matrix to any point in the material, unlike two materials sandwiched together. In structural applications, the matrix is usually a lighter metal such as aluminum, magnesium, or titanium, and provides a compliant support for the reinforcement. In high temperature applications, cobalt and cobalt-nickel alloy matrices are common. The composite materials are commonly classified based on matrix constituent. These three types of matrices produce three common types of composites: 1. Polymer matrix composites (PMCs), of which GRP is the best-known example, use ceramic fibers in a plastic matrix. 2. Metal-matrix composites (MMCs) typically use silicon carbide fibers embedded in a matrix made from an alloy of aluminum and magnesium, but other matrix materials such as titanium, copper, and iron are increasingly being used. Typical applications of MMCs include bicycles, golf clubs, and missile guidance systems; an MMC made from silicon-carbide fibers in a titanium matrix is currently being developed for use as the skin (fuselage material) of the US National Aerospace Plane.

4

3. Ceramic-matrix composites (CMCs) are the third major type and examples include silicon carbide fibers fixed in a matrix made from a borosilicate glass. The ceramic matrix makes them particularly suitable for use in lightweight, hightemperature components, such as parts for airplane jet engines. 1.5.1.1 POLYMER MATRIX COMPOSITES (PMC)/CARBON MATRIX COMPOSITES/CARBON-CARBON COMPOSITES (CCC)

Fig 1.4.2 First classification of matrix phase

A small quantum of shrinkage and the tendency of the shape to retain its original form are also to be accounted for. But reinforcements can change this condition too. The advantage of thermoplastics systems over thermosets are that there are no chemical reactions involved, which often result in the release of gases or heat. Manufacturing is limited by the time required for heating, shaping and cooling the structures. Thermosets are the most popular of the fiber composite matrices without which, research and development in structural engineering field could get truncated. Aerospace components, automobile parts, defense systems etc., use a great deal of

5

this type of fiber composites. Epoxy matrix materials are used in printed circuit boards and similar areas.

Fig 1.4.3 Second classification of matrix phase

Direct condensation polymerization followed by rearrangement reactions to form heterocyclic entities is the method generally used to produce thermoset resins. Water, a product of the reaction, in both methods, hinders production of void-free composites. These voids have a negative effect on properties of the composites in terms of strength and dielectric properties. Polyesters phenolic and Epoxies are the two important classes of thermoset resins. Epoxy resins are widely used in filament-wound composites and are suitable for moulding prepress. They are reasonably stable to chemical attacks and are excellent adherents having slow shrinkage during curing and no emission of volatile gases. These advantages, however, make the use of epoxies rather expensive. Also, they cannot be expected beyond a temperature of 140ºC. 1.5.1.2 METAL MATRIX COMPOSITES (MMC) Metal matrix composites, at present though generating a wide interest in research fraternity, are not as widely in use as their plastic counterparts. High strength,

6

fracture toughness and stiffness are offered by metal matrices than those offered by their polymer counterparts. They can withstand elevated temperature in corrosive environment than polymer composites. Most metals and alloys could be used as matrices and they require reinforcement materials which need to be stable over a range of temperature and non-reactive too. However the guiding aspect for the choice depends essentially on the matrix material. Light metals form the matrix for temperature application and the reinforcements in addition to the aforementioned reasons are characterized by high moduli.

1.5.1.3 CERAMIC MATRIX COMPOSITES (CMC) Ceramics can be described as solid materials which exhibit very strong ionic bonding in general and in few cases covalent bonding. High melting points, good corrosion resistance, stability at elevated temperatures and high compressive strength, render ceramic-based matrix materials a favourite for applications requiring a structural material that doesn’t give way at temperatures above 1500ºC. Naturally, ceramic matrices are the obvious choice for high temperature applications. 1.5.2 MATRIX SELECTION The matrix plays a minor role in the tensile load-carrying capacity of a composite structure. However, selection of a matrix has a major influence on the interlaminar shear as well as in-plane shear properties of the composite material. The interlaminar shear strength is an important design consideration for structures under bending loads, whereas the in-plane shear strength is important under torsion loads. The matrix provides lateral support against the possibility of fibre buckling

7

under compression loading, thus influencing to some extent the compressive strength of the composite material. The interaction between fibres and matrix is also important in designing damage tolerant structures. Finally, the processability and defects in a composite material depend strongly on the physical and thermal characteristics, such as viscosity, melting point, and curing temperature of the matrix.

1.5.2.1

FUNCTIONS OF A MATRIX

In a composite material, the matrix material serves the following functions: • Holds the fibres together. • Protects the fibres from environment. • Distributes the loads evenly between fibres so that all fibres are subjected to the same amount of strain. • Enhances transverse properties of a laminate. • Improves impact and fracture resistance of a component.

1.5.3 REINFORCEMENT PHASE The role of the reinforcement in a composite material is fundamentally one of increasing the mechanical properties of the neat resin system. All of the different fibres used in composites have different properties and so affect the properties of the composite in different ways. However, individual fibres or fibre bundles can only be used on their own in a few processes such as filament winding. For most other applications, the fibres need to be arranged into some form of sheet, known as a fabric, to make handling possible. Different ways for assembling fibres into sheets and the variety of fibre

8

orientations possible lead to there being many different types of fabrics, each of which has its own characteristics. Reinforcements for the composites can be fibers, fabrics particles or whiskers. Fibers are essentially characterized by one very long axis with other two axes either often circular or near circular. Particles have no preferred orientation and so does their shape. Whiskers have a preferred shape but are small both in diameter and length as compared to fibers. A reinforcement that embellishes the matrix strength must be stronger and stiffer than the matrix and capable of changing failure mechanism to the advantage of the composite. This means that the ductility should be minimal or even nil the composite must behave as brittle as possible.

1.5.3.1

FIBER

REINFORCED

COMPOSITES/FIBRE

REINFORCED

POLYMER (FRP) COMPOSITES Fibers are the important class of reinforcements, as they satisfy the desired conditions and transfer strength to the matrix constituent influencing and enhancing their properties as desired. Glass fibers are the earliest known fibers used to reinforce materials. Ceramic and metal fibers were subsequently found out and put to extensive use, to render composites stiffer more resistant to heat. Fibers fall short of ideal performance due to several factors. The performance of a fiber composite is judged by its length, shape, orientation, and composition of the fibers and the mechanical properties of the matrix. The orientation of the fiber in the matrix is an indication of the strength of the composite and the strength is greatest along the longitudinal directional of fiber.

9

This doesn’t mean the longitudinal fibers can take the same quantum of load irrespective of the direction in which it is applied. Optimum performance from longitudinal fibers can be obtained if the load is applied along its direction. The slightest shift in the angle of loading may drastically reduce the strength of the composite. Unidirectional loading is found in few structures and hence it is prudent to give a mix of orientations for fibers in composites particularly where the load is expected to be the heaviest. Short-length fibers incorporated by the open- or close-mould process are found to be less efficient, although the input costs are considerably lower than filament winding. 1.5.3.2

LAMINAR COMPOSITES

Laminar composites are found in as many combinations as the number of materials. They can be described as materials comprising of layers of materials bonded together. These may be of several layers of two or more metal materials occurring alternately or in a determined order more than once, and in as many numbers as required for a specific purpose. Clad and sandwich laminates have many areas as it ought to be, although they are known to follow the rule of mixtures from the modulus and strength point of view. Other intrinsic values pertaining to metal-matrix, metal-reinforced composites are also fairly well known. 1.5.3.3

PARTICULATE REINFORCED COMPOSITES (PRC)

Microstructures of metal and ceramics composites, which show particles of one phase strewn in the other, are known as particle reinforced composites. Square, triangular and round shapes of reinforcement are known, but the dimensions of all

10

their sides are observed to be more or less equal. The size and volume concentration of the dispersoid distinguishes it from dispersion hardened materials. The dispersed size in particulate composites is of the order of a few microns and volume concentration is greater than 28%. The difference between particulate composite and dispersion strengthened ones is, thus, oblivious. The mechanism used to strengthen each of them is also different. The dispersed in the dispersionstrengthen materials reinforces the matrix alloy by arresting motion of dislocations and needs large forces to fracture the restriction created by dispersion. Three-dimensional reinforcement in composites offers isotropic properties, because of the three systematical orthogonal planes. 1.5.3.4

LEATHER COMPOSITES

Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have been discussed. Use of chrome leather particles has been found to improve the consumption of scrap rubber powder in natural rubber formulations. Polymer composites based on leather wastes as fillers are reported to be useful for many applications such as in construction materials, automobile interior moldings, heat and sound insulating boards, shoe soles, flooring materials and moldings with good anti-static properties, air permeability and good appearances. When waste leather fibers are added to elastomers, the former could function as short fiber reinforcement for the matrix provided the inherent fibrous nature of the

11

former is retained during processing. Since processing of elastomers is carried out relatively at high temperatures, retention of the fibrous nature in leather under such conditions however is very difficult. It is therefore prudent to use and consider the leather waste in the particulate form and study its effectiveness either as filler or as a processing aid in elastomer formulations.

1.5.4 ADVANTAGES OF COMPOSITES Summary of the advantages exhibited by composite materials, which are of significant use in aerospace industry are as follows: • High resistance to fatigue and corrosion degradation. • High ‘strength or stiffness to weight’ ratio. As enumerated above, weight savings are significant ranging from 25-45% of the weight of conventional metallic designs. • Due to greater reliability, there are fewer inspections and structural repairs. • Directional tailoring capabilities to meet the design requirements. The fibre pattern can be laid in a manner that will tailor the structure to efficiently sustain the applied loads. • Fibre to fibre redundant load path. • Improved dent resistance is normally achieved. Composite panels do not sustain damage as easily as thin gauge sheet metals. • It is easier to achieve smooth aerodynamic profiles for drag reduction. Complex double-curvature parts with a smooth surface finish can be made in one manufacturing operation. • Composites offer improved torsional stiffness. • Improved friction and wear properties as well as resistance to impact damage.

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CHAPTER 2 LITERATURE REVIEW 2.1 OVERVIEW Literally the term composite means a solid material that results when two or more different substances, each with own characteristics are combined to create a new substance whose properties are superior to those of the original components for any specific application. The term composite more specifically refers to a structural material with in which a reinforcement material is embedded. And the engineering definition would also go along side - A material system composed of a mixture or combination of two or more constituents that differ in form or material composition and air essentially insoluble in each other. In principle, composites can be fabricated out of any combination of two or more materials-metallic, organic, or inorganic; but the constituent forms are more restricted. The matrix is the body constituents, serving to enclose the composite and give it a bulk form. Major structural constituents are fibres, particulates, laminates or layers, flakes and fillers. When two or more materials are interspersed, there is always a contiguous region. Simply this may be the common boundary of the two phases concerned, in which case it is called an interface. A composite having a single interface is feasibly fabricated when the matrix and reinforcement are perfectly compactable. On the other end, there may an altogether separate phase present between the matrix phase and the reinforcement phase. The matrix is body constituent, serving to enclose the composite and give it a bulk form. Major structural are fibres, particulates, laminates or layers, flakes and fillers.

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[1] “Processing and characterization of waste leather based polycaprolactone biocomposites” –Seena Joseph, Tushar Ambone, E. Deenadayalan, et al (December 2015) It infers that addition of leather powder to polycaprolactone (PCL) resulted in improvement of tensile modulus of neat PCL and reduction in percentage crystallinity of PCL matrix was observed with increase in WLB content.

[2] “Polymer sand composites based on the mixed and heavily contaminated thermoplastic waste” – I. Slieptsova, B. Savchenko, N. Sova, A. Slieptsov (2015) This paper gives an idea of the represents production and characterization of highly filled polymer composites based on recycled plastics and sand as a filler. With increase of filling degree from 50% to 80% decrease in tensile strength and increase in compressive and bending strength is observed.

[3]

“Epoxy-silica

particulate

nanocomposites:

Chemical

interactions

reinforcement and fracture toughness” - G. Ragostaa, M. Abbatea, et al (August 2005) The paper discusses that the curing behavior of the epoxy matrix was not adversely affected by the inorganic phase. A conspicuous increase of modulus and yield strength was found by increasing the silica content.

[4] “Natural rubber/leather waste composite foam: A new eco-friendly material and recycling approach” - Nelissa Garcia, Deuber Lincon Agostini, et al (November 2014)

14

This paper inferred that the mechanical parameters were found to depend on the leather dust concentration. Moreover, the stiffness rose with the increase of leather shavings.

[5] “Preparation and characterization of leather polymer composites” – Om Kumar, A. Suresh Babu, Jacob Moses Anbiah (August 2015) This work deals with the utilization of industrial leather wastes, with Poly Vinyl Butyral (PVB) and post-consumer milk pouches, by preparing a composite material as a product that has commercial value and applications.

[6] “Utilization of Spent Tea Leaves and Waste Plastics for Composite Boards” – Juanito P Jimenez Jr., Erlinda Mari, Edgaro M. Vilena, Rico J. Cabangon (January 2013) This paper deals with the use of used tea leaves and waste plastics as composites. The materials exhibited remarkable dimensional stability.

[7] “Effects of spent tea leaf powder on the properties and functions of cellulose green composite films” - J. Duan, K. Obi Reddy, B. Ashok, et al (March 2016) This paper concludes that the used tea leaves along with cellulose as the matrix showed excellent mechanical properties as well as excellent adsorption.

[8] “Physical and Sound Absorption Properties of Spent Tea Leaf Fiber Filled Polyurethane Foam Composite” - Qumrul Ahsan, Chia Pooi Ching, Mohammed Yuhazri bin Yaakob (October 2014)

15

The paper shows that the spent tea leaves provide the best sound absorption coefficient and for composites using granulated fibers from any grade have lower sound absorption coefficient. Also, tea leaves are rich in tannin, which contribute towards high durability, high resistance to fungal and termites, and high resistance to fire. [9] “Natural rubber: leather composites” – K. Ravichandran, N. Nachimuthu (June 2005) This journal infers that suitably neutralized leather wastes can assist the addition of large quantities of scrap rubber into a virgin rubber matrix without affecting the vulcanization characteristics seriously. The natural rubber-scrap rubber compositions containing treated leather could be processed safely in the temperature range of 140 - 150 °C without much reversion in the matrix. Morphological studies of treated leather particles have revealed a loosely bound structure when compared with the closely knitted fibrous structure of the untreated leather.

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CHAPTER 3 COMPOSITE MATERIALS The following materials were used in the preparation of composite samples: 3.1 LEATHER WASTE 3.1.1 LEATHER Leather is a collective term for all hides and skins which have been tanned. These can come from any type of animal. Because it is a by-product of the meat industry most leather is produced from cow, sheep, goat and pigskin. There are smaller amounts of deerskin and exotic leathers such as crocodile, lizard and the like. The majority of leather products are made from cow-hide especially in the upholstery trade as these provide the skin area needed to cut the largest panels. The most common raw material is cattle hide. It can be produced at manufacturing scales ranging from artisan to modern industrial scale. Leather is used to make a variety of articles, including footwear, automobile seats, clothing, bags, book bindings, fashion accessories, and furniture. It is produced in a wide variety of types and styles and decorated by a wide range of techniques. The earliest record of leather artifacts dates back to 2200 BC. 3.1.2 TANNING METHODS Leather is mainly produced by tanning. The different tanning methods are: 

Vegetable-tanned leather is tanned using tannins extracted from vegetable matter, such as tree bark prepared in bark mills. It is the oldest known method. It is supple and brown in color, with the exact shade depending on the mix of materials and the color of the skin. The color tan derives its name from the appearance of undyed vegetable-tanned leather. Vegetable-tanned leather is not

17

stable in water; it tends to discolor, and if left to soak and then dry, it shrinks and becomes harder. This is a feature of oak-bark-tanned leather that is exploited in traditional shoemaking. In hot water, it shrinks drastically and partly congeals, becoming rigid and eventually brittle. Boiled leather is an example of this, where the leather has been hardened by being immersed in hot water, or in boiled wax or similar substances. Historically, it was occasionally used as armor after hardening, and it has also been used for book binding. 

Chrome-tanned leather, invented in 1858, is tanned using chromium sulfate and other chromium salts . It is also known as "wet blue" for the pale blue color of the undyed leather. The chrome tanning method usually takes approximately one day to complete, making it best suited for large-scale industrial use. This is the most common method in modern use. It is more supple and pliable than vegetable-tanned leather and does not discolor or lose shape as drastically in water as vegetable-tanned. However, there are environmental concerns with this tanning method, as chromium is a heavy metal.



Aldehyde-tanned

leather is

tanned

using glutaraldehyde or oxazolidine compounds. It is referred to as "wet white" due to its pale cream color. It is the main type of "chrome-free" leather, often seen in shoes for infants and automobiles. Formaldehyde has been used for tanning in the past; it is being phased out due to danger to workers and sensitivity of many people to formaldehyde. 

Chamois leather is a form of aldehyde tanning that produces a porous and highly water-absorbent leather. Chamois leather is made using marine oils

18

(traditionally cod oil) that oxidize to produce the aldehydes that tan the leather. 

Brain tanned leathers are made by a labor-intensive process that uses emulsified oils, often those of animal brains such as deer, cattle, and buffalo. They are known for their exceptional softness and washability.



Alum leather is transformed using aluminium salts mixed with a variety of binders and protein sources, such as flour and egg yolk. Alum leather is not actually tanned; rather the process is called "tawing", and the resulting material reverts to rawhide if soaked in water long enough to remove the alum salts.

3.1.3 LEATHER GRADES In general, leather is produced in the following grades: 

Top-grain leather includes the outer layer of the hide, known as the grain, which features finer, more densely packed fibers, resulting in strength and durability. Depending on thickness, it may also contain some of the more fibrous under layer, known as the corium. Types of top-grain leather include: 

Full-grain leather contains the entire grain layer, without any removal of the surface. Rather than wearing out, it develops a patina during its useful lifetime. It is usually considered the highest quality leather. Furniture and footwear are often made from full-grain leather. Full-grain leather is typically finished with a soluble aniline dye. Russia leather is a form of fullgrain leather.



Corrected grain leather has the surface subjected to finishing treatments to create a more uniform appearance. This usually involves buffing or sanding away flaws in the grain, then dyeing and embossing the surface.

19



Nubuck is top-grain leather that has been sanded or buffed on the grain side to give a slight nap of short protein fibers, producing a velvet-like surface.



Split leather is created from the corium left once the top-grain has been separated from the hide, known as the drop split. In thicker hides, the drop split can be further split into a middle split and a flesh split. 

Suede is made from the underside of a split to create a soft, napped finish. It is often made from younger or smaller animals, as the skins of adults often result in a coarse, shaggy nap.



Bicast leather is split leather that has a polyurethane or vinyl layer applied to the surface and embossed to give it the appearance of a grain. It is slightly stiffer than top-grain leather but has a more consistent texture.



Patent leather is leather that has been given a high-gloss finish by the addition of a coating. Dating to the late 1700s, it became widely popular after inventor Seth Boyden developed the first mass-production process, using a linseed oil-based lacquer, in Newark, New Jersey, in 1818. Modern versions are usually a form of bicast leather.



Bonded leather, also called reconstituted leather, is a material that uses leather scraps that are shredded and bonded together with polyurethane or latex onto a fiber mesh. The amount of leather fibers in the mix varies from 10% to 90%, affecting the properties of the product.

20

3.1.4 LEATHER WASTE The leather processing industry produces large amounts of solid organic wastes in the form of un-tanned (trimmings , fleshings, splits) and tanned (trimmings, splits and shavings) waste from raw hides and skins, semi-provessed leather, as well as sludge as a result of wastewater treatment. If these solid wastes are not properly treated and disposed of, they can cause environmental damage to soil and groundwater as well as emissions of odour and poisonous greenhouse gases into the atmosphere. Young’s

Density

Poisson’s

Tensile load

Melting

Modulus

(kg/m3)

Ratio

(N/mm2)

temperature

(GPa)

(°C)

0.51

108

0.81

24.3

117

Table 3.1.4 Properties of leather waste

3.2 EPOXY RESIN LY 556 AND HARDENER HY 951 3.2.1 INTRODUCTION Epoxy is either any of the basic components or the cured end products of epoxy resins, as well as a colloquial name for the epoxide functional group. Epoxy resins, also

known

as polyepoxides,

are

a

class

of

reactive prepolymers and polymerswhich contain epoxide groups. Epoxy resins may be reacted (cross-linked) either with themselves through catalytic homopolymerisation, or with a wide range of co-reactants including polyfunctional amines, acids (and acid anhydrides), phenols, alcohols and thiols (usually called mercaptans). These co-reactants are often referred to as hardeners or curatives, and

21

the cross-linking reaction is commonly referred to as curing. Reaction of polyepoxides

with

themselves

or

with

polyfunctional

hardeners

forms

a thermosetting polymer, often with favorable mechanical properties and high thermal and chemical resistance. Epoxy has a wide range of applications, including metal coatings, use in electronics/electrical components/LEDs, high tension electrical insulators, paint brush manufacturing, fiber-reinforced plastic materials and structural adhesives. 3.2.2 EPOXY RESIN LY 556 Epoxy LY 556 is a Bisphenol – A based resin. It is commonly called Araldite LY 556. It sets by the interaction with a hardener, often amine-based. Heat is not necessary although warming will reduce the curing time and improve the strength of the bond. After curing, the joint is impervious to boiling water and all common organic solvents. Important epoxy resins are produced from combining epichlorohydrin and bisphenol A to give bisphenol A diglycidyl ethers. Increasing the ratio of bisphenol A to epichlorohydrin during manufacture produces higher molecular weight linear polyethers with glycidyl end groups, which are semi-solid to hard crystalline materials at room temperature depending on the molecular weight achieved. This route of synthesis is known as the "taffy" process. More modern manufacturing methods of higher molecular weight epoxy resins is to start with liquid epoxy resin (LER) and add a calculated amount of bisphenol A and then a catalyst is added and the reaction heated to circa 160 °C (320 °F). This process is known as "advancement". There are numerous patents and articles on this process which has been popular for over 20 years. As the molecular weight of the resin increases, the epoxide content reduces and the

22

material behaves more and more like a thermoplastic. Very high molecular weight polycondensates (ca. 30 000 – 70 000 g/mol) form a class known as phenoxy resins and contain virtually no epoxide groups (since the terminal epoxy groups are insignificant compared to the total size of the molecule). These resins do however contain hydroxyl groups throughout the backbone, which may also undergo other cross-linking reactions, e.g. with aminoplasts, phenoplasts and isocyanates.

Visual Aspects

Clear/Pale

Colour

Epoxy

Viscosity

Density

Flash

Storage

(Gardner, Content

at 25 °C

at 25 °C

Point

Temperature

ISO 4630)

(eq/kg)

(mPa s)

(g/cm3)

(°C)

(°C)

<=2

5.30 –

10000 -

1.15 –

>200

2 - 40

5.45

12000

1.20

yellow liquid

Table 3.2.2 Properties of Epoxy LY 556

3.2.3 Hardener HY 951 It is an amine-based hardener. It is commonly called Aradur HY 951. It is compatible with epoxy Araldite LY 556, which is to be mixed in the ratio 10:1. It can be used at room temperature. On their own, epoxy resins are very stable fluids with relatively long shelf lives. It is only when mixed with an epoxy hardener that they can cure properly. If applied onto a floor without the hardener, the resin would remain a near liquid indefinitely and could not transform into a durable flooring system. Unlike paints, which rely on the evaporation of moisture to eventually harden into a thin film, an epoxy floor coating achieves its high

23

performance protective characteristics by undergoing a controlled chemical reaction that occurs between carefully calibrated resin and hardener components. Once the different elements of the floor coating are mixed together, some may require “induction”, wherein they are left for 15-30 minutes to react to each other and allow the chemical process to take place before installation. Still other systems may have very short pot lives that demand the blended liquid be immediately “ribboned” out onto the prepared concrete substrate and spread, since leaving the mixed product as a mass in the bucket would further accelerate the reaction speed. When this does occur, the container and contents can becomes very hot and in some cases even begin to emit smoke as a result of the extreme molecular activity. While individual component may be kept on the shelf for months or longer, once the epoxy coating and hardener have been mixed, the contractor may have only 15 minutes to install the combined material. Multiple layers of product may be installed, with the next coating being applied within a recoat window typically falling within the 4 to 12 hour range. The method of application may vary, based on the specific formula’s chemical makeup, thickness, and cure time.

Visual Aspects

Viscosity at 25 Density at 25 °C (mPa s)

°C (g/cm3)

Flash Point

Storage

(°C)

Temperature (°C)

Clear/Pale

10 - 20

0.98

110

yellow liquid Table 3.2.3 Properties of Hardener HY 951

24

2 - 40

3.3 BEACH SAND Sand is a loose granular material blanketing the beaches, riverbeds and deserts of the world. Composed of different materials that vary depending on location, sand comes in an array of colors including white, black, green and even pink. The most common component of sand is silicon dioxide in the form of quartz. The Earth's landmasses are made up of rocks and minerals, including quartz, feldspar and mica. Weathering processes — such as wind, rain and freezing/thawing cycles — break down these rocks and minerals into smaller grains. Unlike some other minerals, quartz is hard, insoluble in water and doesn't decompose easily from the weathering processes. Streams, rivers and wind transport quartz particles to the seashore, where the quartz accumulates as light-colored beach sand. (Although continental sand is composed mostly of quartz, it also contains bits of feldspar and other rock fragments.) Tropical islands, such as the Hawaiian Islands, don't have a rich source of quartz, so the sand is different in those locations. The beach sand on tropical islands often looks white because it is made up of calcium carbonate, which comes from the shells and skeletons of reef-living marine organisms, including corals, mollusks and microorganisms called foraminifera. Sand forms when the reef breaks down, either by mechanical forces — such as waves and currents — or from bio-erosion caused by grazing fish, urchins and other marine life. The famous pink sand of Bermuda is also composed of eroded calcium carbonate; the sand gets its ruddy hue from the abundant red foraminifera, Homotrema rubrum. Tropical beaches

25

may also have black sand, which is composed of black volcanic glass. Sometimes, erosive forces separate the mineral olivine from other volcanic fragments, leading to green sand beaches, such as Hawaii's Papakōlea Beach. Specific

Particle Size

Minimum dry

Maximum

Critical state

Gravity

d10, d50, d60

density

dry density

friction angle

(mm)

(kg/m3)

(kg/m3)

(°)

0.10, 0.19,

1461

1774

30

2.65

0.22 Table 3.3 Properties of Beach Sand

3.4 TEA WASTE Tea is one of the most popular beverages in the world and is professed as being healthy. Statistics indicate that the annual tea production in the world reached about 4.5 million tons. Mainly tea is obtained from the leaves of Camellia sinensis L. Spent tea leaves (STL) remain after the preparation of tea and result as a solid waste product. Waste tea not only pollutes the environment but also represents a loss of valuable resource. To tackle this problem, during the past few decades, some researchers investigated the possibility of exploiting STL as adsorbents for synthetic dyes and toxic metals, bio-energy, and as reinforcing filler for construction and polymer composites. Moisture Content

Specific Surface

(%)

Area (m2/g)

11.85

174.8

Specific gravity

True bulk Density (g/cm3)

0.286

Table 3.4 Properties of Tea waste

26

1.02

3.5 GLASS FIBRE Glass fiber also called fiberglass. It is material made from extremely fine fibers of glass Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes. Glass is the oldest, and most familiar, performance fiber. Fibers have been manufactured from glass since the 1930s. They have been one of the most frequently used filler materials in composites due to their low weight and high tensile strength as well as resistance to chemical and thermal attack. The type used in the project is class E fibre, due to its low cost and nigh - chemical resistive nature. Tensile

Compressive

Density

Thermal

Softening

Strength

Strength

(g/cm3)

Expansion

Temperature

(MPa)

(MPa)

(μm/m°C)

(°C)

3445

1080

5

846

2.58

Table 3.5 Properties of Glass fibre

27

CHAPTER 4 PROJECT WORK PLAN

Literature & Journal references

Site Selection

Material Purchase

Mould making

Preparation of composite (using hand layup)

Testing

Calculations and Analysis

Result compilation

Report Generation

28

CHAPTER 5 EXPERIMENTAL PROCEDURE 5.1 MOULD MAKING The prerequisite of any composite preparation process lies within the process of mould making. It is important to satisfy the various parameters of the mould to ensure that the composite formed is free of any irregularity or crevices. The mould is made out of mild steel sheets. The preparation stage consists of the following stages: 

DEMARCATING

The sheet metal of the required length is demarcated along its length to be ready for the cutting operation.

Fig. 5.1.1 Demarcating process

29

 CUTTING After marking, the sheet metal is cut along the marked contours using a cutting vice.

Fig. 5.1.2 Cutting process

 BENDING The cut sheet metal is again marked along the edges to be bent. It is then bent to the required dimensions using a vice and mallet. A minimum of four moulds had been prepared for the composite making process.

30

Fig. 5.1.3 The prepared mould

5.2 COMPOSITE PREPARATION The composite was prepared using hand layup method. Initially, the mould is prepared by cleaning its inner surfaces off dirt and oils using wet wipes. It is then placed on a smooth wooden work surface and the base is taped using cello tape to prevent the resin mixture from seeping out and also to hold the mould into place. The mould is coated with a layer of buffing wax and butter paper is placed onto it to aid in easier removal of the composite.

31

Fig. 5.2.1 Laying the filler materials

The resin and hardener are mixed thoroughly in the ratio 10:1 in batches and the first layer of resin is poured into the mould. The mould set up is tilted along the sides to distribute the resin evenly. Then, calculated amounts of the filler materials are laid up onto the resin, followed by another layer of resin mixture. It is to be kept in mind that the resin mixture is to soak the filler materials thoroughly, otherwise this could lead to formation of air bubbles and eventually weaken the composite internally.

Fig. 5.2.2 Applying resin onto filler material

32

The layers of resin-filler materials are laid up until the mixture reached a thickness of about a centimeter, the last layer of resin is poured and the surface is smoothened using a roller. It is then shaken moderately to remove any air bubbles. A slab of brick is placed onto the composite mixture to compress it and remove further air bubbles.

Fig. 5.2.3 Weight placed on apparatus

The set up is left to cure at ambient temperature where a temperature rise is observed, within the range of 90 – 140 °C, hot to the touch but insufficient enough to burn the filler materials. The curing time lasted for about two days to yield better results. Similarly, the other composites of varying filler materials were prepared.

33

Fig. 5.2.4 One of the prepared composites

For the hardness testing and study purpose, a separate batch of samples (using a combination of leather waste and other fillers without glass fibre) were prepared, this time using a plastic disposable cup as the mould. The samples were about 5 cm in diameter and approximately 1 cm thick.

Fig. 5.2.5 The prepared composites for hardness testing

34

The samples were subjected to the following tests:  Flexural Test  Tensile test  Impact Test  Hardness test 5.3 THE TESTS 5.3.1 FLEXURAL TEST Flexural test, or compression test, is designated by the code ASTM D790. These test methods cover the determination of flexural properties of unreinforced and reinforced plastics, including high-modulus composites and electrical insulating materials in the form of rectangular bars molded directly or cut from sheets, plates, or molded shapes. These test methods are generally applicable to both rigid and semi-rigid materials. However, flexural strength cannot be determined for those materials that do not break or that do not fail in the outer surface of the test specimen within the 5.0 % strain limit of these test methods. These test methods utilize a three-point loading system applied to a simply supported beam. The flexural testing machine for three point loading system is shown below.

35

Fig. 5.3.1 Flexural Test Machine

5.3.2 TENSILE TEST It is designated by the code ASTM D638. This test method is designed to produce tensile property data for the control and specification of plastic materials. These data are also useful for qualitative characterization and for research and development. Some material specifications that require the use of this test method, but with some procedural modifications that take precedence when adhering to the specification. Therefore, it is advisable to refer to that material specification before using this test method. Tensile properties are known to vary with specimen preparation and with speed and environment of testing. Consequently, where precise comparative results are desired, these factors must be carefully controlled. The tensile testing machine apparatus is shown below.

36

Fig. 5.3.2 Tensile Testing Machine

5.3.3 IMPACT TEST One of the most common tests, of the physical characteristics of plastic materials is the notched Izod impact test as specified by ASTM D 256 Standard Test Method for Determining the Izod Pendulum Impact Resistance of Plastics. This test fixes one end of a notched specimen in a cantilever position by means of a vice. A striker on the arm of a pendulum or similar energy carrier then strikes the specimen. The energy absorbed by the specimen in the breaking process is known as the breaking energy. The breaking energy can be converted into an indication of a materials impact resistance using such units as foot-pounds or joules. While use of the data generated from a test for designing a part is not necessarily recommended, it still provides reasonable service as a quality control tool. Most US resin manufacturers have years of Izod test data and many customers are accustomed to selecting product based on the data.

37

5.3.4 HARDNESS TEST Shore hardness is a measure of the resistance of a material to penetration of a spring loaded needle-like indenter. Hardness of Polymers (rubbers, plastics) is usually measured by Shore scales. Hardness of hard elastomers and most other polymer materials (Thermoplastics, Thermosets) is measured by Shore D scale. Shore hardness is tested with an instrument called Durometer, which utilizes an indenter loaded by a calibrated spring. The measured hardness is determined by the penetration depth of the indenter under the load. Two different indenter shapes (see the picture below) and two different spring loads are used for two Shore scales (A and D). The loading forces of Shore A: 1.812 lb (822 g), Shore D: 10 lb (4536 g). Shore hardness value may vary in the range from 0 to 100. Maximum penetration for each scale is 0.097-0.1 inch (2.5-2.54 mm). This value corresponds to minimum Shore hardness: 0. Maximum hardness value 100 corresponds to zero penetration.

38

CHAPTER 6 CALCULATIONS 6.1 GENERAL SPECFICATIONS The various amounts of materials used were weighed using a beaker and portable digital weighing machine and the values were tabulated and calculated. Parameters

Composite Slab

Composite Pellets

Dimensions (cm)

23 x 23 x 0.7

5 (dia) x 1 (thickness)

Volume (m3)

370.3 x 10-6

1.57 x 10-6

Table 6.1 Specifications of slabs

Weight of 1 L resin bottle Resin density

= =

1.071 kg

Mass/Volume =

1.071/1x10-5

=

1071 kg/m3

6.2 LEATHER WASTE + GLASS FIBRE COMPOSITE SLAB (SAMPLE 1) Weight of slab

=

398 g

Weight of resin used

=

321.3 g

% weight of resin in slab

=

321.3x100/398

=

80.72 %

Weight of glass fibres of size 23x23 cm

=

60 g

% weight of glass fibre

=

60/398

39

=

15.07 %

Weight of leather waste used

=

16.67 g

% weight of leather waste

=

16.67/398

=

4.1 %

=

4.1 : 15.07 : 80.72

Ratio L:G:E

Simplified ratio (with respect to leather waste)

=

1 : 3.67 : 19.68

6.3 BEACH SAND + LEATHER WASTE COMPOSITE SLAB (SAMPLE 2) Using the same formula, the ratio was calculated to be 1 : 2.44 : 0.68 6.4 LEATHER WASTE + GLASS FIBRE + TEA WASTE COMPOSITE SLAB (SAMPLE 3) Using the same formula, the ratio was calculated to be 1 : 1.2 : 0.55 : 3.01 Table 6.2 TABULATION OF RESULTS Composite

Sample 1 Sample 2 Sample 3

Percentage of fillers used (% by weight) Leatherwaste Beach Tea Glass Resin Sand Waste Fibre 4.1 23.5 18

57.5 -

21.7

40

15.07 80.72 16 9.9 54.2

Weight of slab (g) 398 902 603.2

Ratio (With respect to leather waste) 1 : 3.67 : 19.68 1 : 2.44 : 0.68 1: 1.2 : 0.55 : 3.01

CHAPTER 7 RESULTS AND DISCUSSION 7.1 FLEXURAL TEST The flexural tests were carried out using computerized universal testing machine as per ASTM standards. The machine utilizes a three point loading system applied on a specimen of simply supported configuration. Three specimens are used for the test and the value is tabulated and the graph is generated. Fig. 7.1.1 shows the ASTM D790 standard dimensions, which is used for the testing purpose.

Fig 7.1.1 Specimen dimensions for flexural/bending test (mm)

And accordingly, the samples are prepared to dimensions as shown in fig 7.1.2.

Fig 7.1.2 The prepared samples (after testing)

41

The flexural tests of the three composite slabs are observed in the following results accordingly: SAMPLE 1

42

SAMPLE 2

43

SAMPLE 3

44

The flexural tests of the three composite slabs are summarized in the graph below:

Flexural Load (kN) 1.2 1

0.95

0.98

0.8

0.72

0.6 Flexural Load (kN) 0.4 0.2 0 Sample 1

Sample 2

Sample 3

Fig. 7.1.3 Flexural Test Graph

From the graph, it can be seen that the sample 2 (beach sand + leather waste) has a higher value of flexural load as compared to the samples 1 (leather waste + glass fibre) and samples 3 (Leather waste + glass fibre + tea waste) The addition of tea waste causes a reduction in the flexural load, while the inclusion of sand contributes to the higher flexural durability. Furthermore, the reason for the reduction in the flexural durability in sample 3 could be due to the presence of milk particles, which easily break down and cause weakening of the resin-fibre bond. Since complete purification of the tea waste is a tedious and expensive process, it is used powdered and untreated.

45

7.2 TENSILE TEST The tensile tests were carried out using computerized universal testing machine as per ASTM standards. Three samples of each specimen are used for each test and average value is reported. The fig. 7.2 shows the ASTM D638 standard dimensions, which is used for the testing purpose.

Fig 7.2.1 Specimen dimensions for tensile test (mm)

And accordingly, the samples are prepared to dimensions as shown in fig 7.2.2.

Fig 7.2.2 The prepared samples (after testing)

46

The tensile tests of the three composite slabs are observed in the following results accordingly: SAMPLE 1

47

SAMPLE 2

48

SAMPLE 3

49

The tensile tests of the three composite slabs are summarized in the graph below: 60 51.75

Tensile Test Parameters

50

40

30

Fmax (kN) UTS (MPa) 18.71

20

9.18

10 3.51

2.39

1.61

0 Sample 1

Sample 2

Sample 3

Fig. 7.2.3 Tensile Test Graph

From the graph, it can be seen that the sample 1 (Leather waste + glass fibre) has a higher value of tensile strength as compared to the samples 2 (beach sand + leather waste) and samples 3 (Leather waste + glass fibre + tea waste), while Fmax also tends to vary respectively in the samples. The inclusion of beach sand or tea waste did not contribute to higher tensile durability. Instead the beach sand contributed its brittle nature in sample 2, which has the lowest value of tensile durability.

50

7.3 IMPACT TEST The load is applied as an impact blow from a weighted pendulum hammer that is released from a position at a fixed height h. The specimen is positioned at the base and with the release of pendulum, which has a knife edge, strikes and fractures the specimen at the notch. The dimensions of a standard specimen for ASTM D256 are 63.5 × 12.7 × 3.2 mm (2.5 × 0.5 × 0.125 in). The most common specimen thickness is 3.2 mm (0.13 in), but the width can vary between 3.0 and 12.7 mm (0.12 and 0.50 in).

Fig 7.3.1 Specimen dimensions for Izod test

And accordingly, the samples are prepared to dimensions as shown in fig 7.2.2.

Fig 7.3.2 The prepared samples (after testing)

51

The impact tests of the three composite specimens are observed in the following results accordingly: Parameter

Sample 1

Sample 2

Sample 3

Impact Values

12

2

10

(Joules) Table 7.3.1 Impact Test values

The impact tests of the three composite slabs are summarized in the graph below:

Impact Values (Joules) 14 12

12 10

10 8

Impact Values (Joules)

6 4 2

2 0 Sample 1

Sample 2

Sample 3

Fig. 7.3.3 Impact Test Graph

From the above data, it can be seen that sample 1 (Leather waste + Glass fibre) has the highest impact strength of 12 J as compared to sample 3 (Leather waste + Glass fibre + tea waste) and sample 2 (beach sand + leather waste). The brittle nature of the sand caused the sample 2 to break off easily at just 2 J. The tea waste in sample 3 added to the toughness and was able to hold the sample together until 10 J.

52

7.4 HARDNESS TEST Durometer Hardness is used to determine the relative hardness of soft materials, usually plastic or rubber. The test measures the penetration of a specified indentor into the material under specified conditions of force and time. The hardness value is often used to identify or specify a particular hardness of elastomers or as a quality control measure on lots of material. The specimen is first placed on a hard flat surface. The indenter for the instrument is then pressed into the specimen making sure that it is parallel to the surface. The hardness is read within one second (or as specified by the customer) of firm contact with the specimen. The test specimens are generally 6.4mm (¼ in) thick. It is possible to pile several specimens to achieve the 6.4mm thickness, but one specimen is preferred.

Fig 7.4.1 Shore D hardness test

53

The hardness tests of the three composite specimens are observed in the following results accordingly: Parameter

Sample 1

Shore D hardness 52

Sample 2

Sample 3

42

44

Table 7.4.1 Hardness Test values

The hardness tests of the three composite slabs are summarized in the graph below:

Shore D hardness 60 50 40 30

Shore D hardness

20 10 0 Sample 1

Sample 2

Sample 3

Fig. 7.4.3 Hardness Test Graph

From the above data, it can be seen that sample 1 (Leather waste + Glass fibre) has the highest hardness of 52 as compared to sample 3 (Leather waste + Glass fibre + tea waste) and sample 2 (beach sand + leather waste). The inclusion of beach sand reduced the toughness of the material, while the tea waste contributed to the high hardness value of the sample 3 due to the rich tannin content in it.

54

7.5 OVERALL COMPARISON The overall comparison of the various parameters of the three composite specimens can be summarized as follows: Parameter

Sample 1

Sample 2

Sample 3

Tensile load (kN)

3.51

1.61

2.39

Tensile Strength

51.75

9.18

18.71

0.95

0.98

0.72

12

2

10

52

42

44

(MPa) Flexural Load (kN) Impact values (Joules) Shore D hardness

Fig 7.5.1 The observed values of the specimens

The graphs of the above data can be summarized as follows: 60 52

51.75 50

44

42 40

Tensile Load (kN) Tensile Strength (MPa)

30

Flexural Load (Kn) 18.71

20 12 10 3.51

0.95

Shore D Hardness 9.18 1.61

2.39

0.98

0 Sample 1

Impact Values (J)

Sample 2

0.72 Sample 3

55

CHAPTER 8 COST ESTIMATION

S. No

DESCRIPTION

QUANTITY

1

Epoxy Resin LY

2 kg

556

COST (Rs.)

1320

2

Hardener HY 951

200 g

3

Glass fibre fabric

1 (1.5 m x 1.5 m)

500

4

Leather waste

1 kg

Collected from tannery

5

Roller

1

50

6

Brush

1

20

7

Buffing Wax

200 g

150

8

Measuring Cup

1

88

(500 ml) 9

Polythene Sheets

2

40

10

Gloves

6

160

11

Testing

3 specimens

3100

Total

5428

Table 10.1 Cost Estimation table

56

CHAPTER 9 CONCLUSION

The present investigation dealt with the preparation of leather waste, sand and used tea powder composites through the hand layup method. The flexural, bending, hardness and impact tests of the specimens were tested and their results were compared. The conclusions based on the current work on the preparation and analysis of composites laced with leather waste, beach sand and tea waste are as follows: The inclusion of beach sand in the composite resulted in the increase in flexural load and composite weight but reduction in other properties such as tensile strength, hardness etc. The addition of tea waste and leather waste to the composite resulted in a slight enhancement of strength properties. The tea waste increased the hardness of the composite but at the same time, decreased the flexural load. The use of leather waste and glass fibre alone was sufficient as there was enormous increase in the tensile strength as compared to the other two samples. The use of leather waste in the composite led to the increase in mechanical properties. Sample 1 (4.1 % LW, 15.07 % GF) had an impact energy of about 12 J, which can be compared to the impact strength of steel (16 J), followed by sample 3 (18 % LW, 21.7 % STL, 9.9% GF) having impact energy of 10 J and sample 2 (23.5 % LW, 54.5 % S) the lowest of the three with impact energy of 2 J. Thus the Sample 1 composite was found to be the best, when compared with the other two samples. The resulting composite can be implemented in the use of floor tiles, as heat seals in refrigerators and air conditioners, as well as wall linings in theatre halls.

57

CHAPTER 9 APPENDIX

58

59

60

61

62

63

64

CHAPTER 10

REFERENCES

1. “Processing

and

characterization

of

waste

leather

based

polycaprolactone biocomposites” –Seena Joseph, Tushar Ambone, E. Deenadayalan, et al (December 2015) 2. “Polymer sand composites based on the mixed and heavily contaminated thermoplastic waste” – I. Slieptsova, B. Savchenko, N. Sova, A. Slieptsov (2015) 3. “Epoxy-silica particulate nanocomposites: Chemical interactions reinforcement and fracture toughness” - G. Ragostaa, M. Abbatea, et al (August 2005) 4. “Natural rubber/leather waste composite foam: A new eco-friendly material and recycling approach” - Nelissa Garcia, Deuber Lincon Agostini, et al (November 2014) 5. “Preparation and characterization of leather polymer composites” – Om Kumar, A. Suresh Babu, Jacob Moses Anbiah (August 2015) 6. “Utilization of Spent Tea Leaves and Waste Plastics for Composite Boards” – Juanito P Jimenez Jr., Erlinda Mari, Edgaro M. Vilena, Rico J. Cabangon (January 2013)

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7. “Effects of spent tea leaf powder on the properties and functions of cellulose green composite films” - J. Duan, K. Obi Reddy, B. Ashok, et al (March 2016 8. “Physical and Sound Absorption Properties of Spent Tea Leaf Fiber Filled Polyurethane Foam Composite” - Qumrul Ahsan, Chia Pooi Ching, Mohammed Yuhazri bin Yaakob (October 2014) 9. https://www.florock.net/2017/09/epoxy-hardeners-use/ 10.http://www.mdp.eng.cam.ac.uk/web/library/enginfo/cueddatabooks/material s.pdf 11.http://www.neumannleathers.com/leatherinfo.htm

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