DEVELOPMENT OF LOW COST PLASTIC INJECTION

MOULDING MACHINE

A PROJECT REPORT

Submitted by

A.ARUL PATRICK RAJA 21806114005

M.ARVIND 21805114007

B.ASHOK KUMAR 21805114008

V.K. HEMANATHAN 21805114022

In partial fulfillment for the award of the degree

of

BACHELOR OF ENGINEERING

in

MECHANICAL ENGINEERING

SRI MUTHUKUMARAN INSTITUTE OF TECHNOLOGY

Chikkarayapuram, Chennai-600069

ANNA UNIVERSITY: CHENNAI 600 025

APRIL 2010

ANNA UNIVERSITY : CHENNAI 600 025

BONAFIDE CERTIFICATE

Certified that this project report “DEVELOPMENT OF LOW COST PLASTIC

INJECTION MOULDING MACHINE” is the bonafide work of “A. ARUL

PATRICK RAJA, M. ARVIND, B. ASHOK KUMAR, V. K.

HEMANATHAN” who carried out the project work under my supervision.

Submitted for the Anna University Practical Examination held on______________

SIGNATURE SIGNATURE

Prof.S.Mukundan Mr. M. Arsath Rahuman Project Guide

HEAD OF THE DEPARTMENT SENIOR LECTURER

Department of Mechanical Engineering Department of Mechanical Engineering Sri Muthukumaran Institute of Technology Sri Muthukumaran Institute of Technology Chikkarayapuram, Chennai – 600 069 Chikkarayapuram, Chennai – 600 069

ACKNOWLEDGEMENT

We render our profound and heartfelt gratitude to our principal

Dr.M.SUNDAR SRI MUTHUKUMARAN INSTITUTE OF TECHNOLOGY,

CHENNAI-69 for his encouragement and co-operation in accomplishing our

project entitled as “DEVELOPMENT OF LOW COST PLASTIC INJECTION

MOULDING MACHINE”

We thank our head of the department Prof.S.Mukundan for allowing us to

undertake this project. His advices and guidance along with our enthusiasm

showed us the path to achieve our cherished goal.

We are indebted to our guide Mr.M.Arsath Rahuman whose persistent

guidance has helped us to achieve success. We also reveal our sincere thanks to the

faculty members of Mechanical department whose suggestion and teaching

brought the comprehension to complete this project.

We would like to take this opportunity to thank our friends for their

endurance, patience and support in achieving our ambition.

We remain with gratitude to our parents, lecturers, non-teaching staff and

management (SRI MUTHUKUMARAN EDUCATIONAL TRUST) forever.

ABSTRACT

The objective of the project is to develop a low cost plastic injection

moulding machine by using conventional injection moulding process.

Injection moulding is used to produce many parts like bottle caps,

containers, plastic combs, home appliances and most other plastic

products that we use today. Injection moulding is the only technique for

producing many idle products in large volume and the most common

method in part manufacturing. Low labor costs, materials can be used in

wide range, scrap losses are minimal and high tolerances are repeatable

are some of the advantages of the injection moulding techniques.

The basic injection moulding process involves the feeding of

granulated thermoplastic into the hopper, which is then sent to the

heating chamber by a plunger which is operated by a rack and pinion

arrangement. The heating chamber melts the plastic which is then forced

into the die. The die is held by a clamping unit which holds the die while

the molten plastic is forced through the die. The die is removed after

sometime to get the final product.

LIST OF TABLES PAGE NO

Table 1.1 - Types of Thermoplastic Materials

Table 3.1 - Properties of Thermoplastic Materials

Table 4.1 - For Spring

Table 4.2 - For Pinion

Table 4.3 - For Mould

Table 4.4 - For Clamping Force And Torque

Table 4.5 - For Heating coil

LIST OF FIGURES PAGE NO

Fig 1.1 - Plunger Injection Moulding Machine

Fig 1.2 - Screw Type Machine

Fig 1.3 - Two Plate Mould

Fig 1.4 - Three plate mould

Fig 1.5 - Delayed action Mould

Fig 1.6 - Methodology

Fig 3.1 - Injection Moulding Machine

Fig 5.1 - Detailed View Of L – Bracket

Fig 5.2 - Detailed View Of Rack And Pinion Holder

Fig 5.3 - Detailed View Of Clamping Unit Lock Nut

Fig 5.4 - Detailed View Of Rack

Fig 5.5 - Detailed View Of Clamping Unit

Fig 5.6 - Detailed View Of Spring

Fig 5.7 - Detailed View Of Injection Unit

Fig 5.8 - Detailed View Of heating coil

LIST OF ABBREVIATION

DESIGN OF PINION

SYMBOL ABBREVATION

Z1 No of teeth on pinion

Z2 No of teeth on wheel

D Diameter of pinion in ‘mm’

Pc Pitch circle in ‘mm’

d1 Circular Pitch diameter in ‘mm’

V Velocity in m/s

N Pinion speed in rpm

F Plunger force in ‘N’

Ft Tangential plunger force in ‘N’

P Power in watts

σc Compressive stress in N/mm2

σb Bending stress in N/mm2

I Gear ratio`

Ko Shear stress factor

M Module in ‘mm’

Fs Static load in N

B Face width in ‘mm’

Y Form factor

Fd Dynamics load in ‘mm’

Vm Pitch line velocity m/s

E Errors in action in ‘mm’

Q Ratio factor

Fw Wear load in N

K Load stress factor N/mm2

a Centre distance in mm

SPRING SPECIFICATION

P Pitch in ‘mm’

D Diameter of wire in ‘mm’

D Mean diameter of the spring in ‘mm’

C Spring index

K Stiffness in N/mm

L Length of the spring in ‘mm’

Ls Solid length in ‘mm’

∂ Deflection of the spring in ‘mm’

W Axial load on the spring in N

N Number of active coils

G Modulus of rigidity of the spring material in N/mm2

τmax Maximum shear stress induced in the wire N/mm2

α Helix angle in degree

TORQUE :

Fcavity Load applied on the cavity in N

Wcavity Clamping force in N

Pscrew Load applied on the circumference of the screw in N

D0 Outer diameter of the screw in ‘mm’

Di Inner diameter of the screw in ‘mm’

Φ Angle of friction in degree

Pwheel To tangential force to be given on the wheel in N

L Length of the handel in mm

dpitch Pitch diameter in mm

Dwheel Wheel diameter of handel in mm

T Torque in N/mm

D Diameter of the mould in ‘mm’

α Helix angle

P Pitch in ‘mm’

Dwheel Mean circumference of the screw in mm

μ Coefficient of friction

HEATING COIL :

P Power in watts

M Mass of the finished product including loses in Kg

Cp Specific heat capacity in J/KgK

ηcoil Efficiency of the coil

T Time of melting

Tmelt Melting temperature in degree

Tatm Atmospheric temperature in degree

TABLE OF CONTENT

CHAPTER NO TITLE PAGE NO

ABSTRACT 123

LIST OF TABLES

LIST OF FIGURES

LIST OF SYMBOL

1. INTRODUCTION

1.1Evolution Of Injection Moulding

1.2Classification Of Polymers

1.2.1 Thermoplastic Materials

1.2.2 Thermosetting Plastics

1.3 Injection Moulding Machine

1.3.1 Types Of Injection Moulding Machine

1.3.1.1 Plunger Injection Moulding

Machine

1.3.1.2 Screw Type Machine

1.3.1.3 Pre Plasticizing Machine

1.4 Mould

1.4.1 Types Of Mould

1.4.1.1 Two Plate Mould

1.4.1.2 Three Plate Mould

1.4.1.3 Split Mould

1.4.1.4 Delayed Action Mould

1.4.1.5 Runner Less Mould

1.5 Mould Material Selection Criteria

1.6 Injection Moulding Technique Process

1.7 Application of Injection Moulding

1.8 Methodology

2. LITERATURE REVIEW

2.1 Introduction To Plastic Process

2.2 Fundamentals Of Polymers

2.3 Thermoplastic Materials

2.4 Mould Fabrication

2.5 Material Selection Criteria

2.6 Plants Visited

2.6.1 L&T Demag Plastic Division

2.6.2 S.A Plastics

3. SELECTION OF LOW COST PLASTIC INJECTION

MOULDING MACHINE

3.1 Reason For Selection

3.2 Components Of Injection Moulding Machine

3.2.1 Injection Unit

3.2.2 Heating Unit

3.2.3 Clamping Unit

3.2.4 Mould

3.3 Selection Of Mould Material

3.4 Material Considered

3.4.1 High Density Polyethylene

3.4.2 Polypropylene

3.4.3 Mild steel

3.4.4 Stainless Steel

4. DESIGN OF VARIOUS COMPONENTS

4.1 Introduction

4.2 Design Procedure adopted

4.2.1 Design Of Spring

4.2.2 Design Of Pinion

4.2.3 Design Procedure Of Heating coil

4.2.4 Design Of Clamping Force And Torque

4.2.5 Design Of Volume Of Component

4.3 Known Parameters

4.4 Materials Properties For Various Components

4.5 Design Of Pinion

4.6 Volume Of component

4.7 Heating Coil Calculation

4.7.1 Experimental Observation

4.8 Design Of spring

4.9 Torque Calculation

4.10 Specification

5. DRAFTING AND MODELLING

6. FABRICATION OF VARIOUS COMPONENTS

6.1 L- Bracket

6.2 Mould

6.3 Assembly

6.4 Installation

CONCLUSION

RECOMMENDATION FOR FUTURE WORK

CHAPTER 1

INTRODUCTION

1.1 EVOLUTION OF INJECTION MOULDING:

One of the earliest forms of plastic moulding was Compression Moulding.

Here, a fixed amount of plastic is placed in the lower half of a mould and heated

before the upper half of the mould is closed over the top of it. The mould remains

closed while the part cools and when it is taken off the ‘flash’ (excess material that

seeps between the two halves of the mould) is removed.

Transfer Moulding introduces a plunger, or ram, that pushes the plastic

through a barrel and into the mould cavity, which is already closed. Transfer

Moulding reduces the amount of waste and removes the need for de-flashing.

Some waste material is still produced though, in the barrel and interconnecting

parts of the mould (depending on its shape).

Plunger Moulding has the plunger mounted horizontally and the plastic fed

into the barrel from a hopper mounted on top. As the plunger moves along the

barrel it automatically cuts off the supply of granules, leaving a fixed amount of

material in the barrel for injecting. The barrel has a nozzle at its end that connects

to the mould and the mould itself has a ‘sprue’ or narrow channel through which

the plastic moves on its way to the mould cavity.

1.2 CLASSIFICATION OF POLYMERS:

Polymers is a large macromolecule built up of repetition of small and simple

chemical units called monomers. Polymer can be of long chain molecules or

branched long chain molecules or molecules of interconnected three dimensional

networks. The repeat unit of the polymer is equivalent or nearly equivalent to the

monomer or starting material from which the polymer is formed.

Plastics are a family of materials not a single material, each member of

which has its own distinct and special advantage. Whatever their properties of

form, however, most plastics fall into one or two groups they are,

Thermoplastics

Thermosetting plastics

The basis for this classification is the way in which the monomer was

polymerized. Addition polymerization produces thermoplastics materials and

condensation polymerization usually produces, thermosetting materials. Of greater

importance are the properties of threes materials as final products.

1.2.1 Thermoplastics materials:

Thermoplastic polymers are characterized by softening upon heating and

hardening by cooling. Since the giant molecules of these materials have no strong

bends between the individual molecules, they can be softened by heat and

remoulded over and over again. This is an advantage in moulding process such as

extrusion or injection where scrap or rejected products can be reground and mould

again. Some of the thermoplastic materials will burn freely when exposed to an

open flame while others of this group will not support combustion.

Merits of thermo plastic materials:

Thermoplastic materials have the potential to be recyclable since they

can be moulded, extruded and reused.

Thermoplastics also require little or no compounding, with no need to

add reinforcing agents, stabilizers or cure systems.

Hence, batch-to-batch variations in weighting and metering

components are absent, leading to improved consistency in both raw

materials and fabricated articles.

TPEs can be easily colored by most types of dyes. Besides that, it

consumes less energy and closer and more economical control of

product quality is possible.

Demerits of thermoplastics:

TPEs relative to conventional rubber or thermoset are relatively high cost of

raw materials, general inability to load TPEs with low cost fillers such as carbon

black (therefore preventing TPEs from being used in automobile tires), poor

chemical and heat resistance, high compression set and low thermal stability.

Application:

It is used in the automotive sector and in household appliances.

It is widely used for catheters where nylon block copolymers offer a

range of softness ideal for patients.

Styrene block copolymers are used in shoe soles for their ease of

processing, and widely as adhesives.

TPE is commonly used to make suspension bushings for automotive

performance applications because of its greater resistance to

deformation when compared to regular rubber bushings.

TPE is also finding more and more uses as electrical cable

jacket/inner insulation, mostly in Portable Cord.

Examples of Thermoplastics materials :

Polyethylene Low density polyethylene (LDPE)

High density polyethylene (HDPE) Polypropylene

Polystyrene Acrylonitrile butadiene (ABS)

Polyvinyl chloride Polyamides

Nylon 6/6 Polycarbonates

Acetal Acrylics

Cellulose plastics Cellulose acetate butyrate (CAB)

Cellulose nitrate Fluoro plastics (PTFE)

Table 1.1 types of thermoplastics

1.2.2 Thermosetting plastics:

The group of thermosetting polymers numbering less than the thermoplastic

group, possesses quite different characteristic. Because of the irreversible reaction

by which they polymerize they form a rigid, hard and often brittle, infusible mass.

The cross-linking molecular structure with strong chemical bonds between the

polymer chains causes these materials to be rigid and hard as no slippage can occur

between polymer chains. Since all the bonds are strong, when the material is

heated no chain flow or softening can occur. Intensive heating of a thermo set will

cause breakage of the chemical bonds resulting in a charring of the material. They

are not flammable. In general thermosetting plastics can be described as being

hard, strong and rigid, with good heat resistance.

Examples of thermosetting plastics:

Urea-formaldehyde

Bakelite

Melamine resin

Polyesters

Polyimide

Epoxy

Merits of thermosetting plastics:

Some of the merits of the thermosetting plastics are they retain their

strength and shape even when heated. This makes thermosetting plastics well-

suited to the production of permanent components and large, solid shapes.

Additionally, these components have excellent strength attributes (although they

are brittle), and will not become weaker when the temperature increases.

Applications:

Thermosetting plastics have their applications in saxophone mouthpieces,

whistles, cameras, solid-body electric guitars, appliance casings.

Melamine resin is often used in kitchen utensils and plates.

Polyester epoxies are used as powder coatings for washers, driers and other

"white goods".

In the aerospace industry, epoxy is used as a structural matrix material which

is then reinforced by fiber.

Materials like wood, and others that are 'low-tech' are glued with epoxy resin

internally stiffened with foam and completely covered with plywood

1.3 INJECTON MOULDING MACHINE:

From the moment we get up in the morning until the moment we go to bed

at night we are surrounded by products that have been produced, wholly or

partially, on Injection Moulding Machines. The alarm clock, shower head, hair

brush, coffee machine, toaster, toothbrush – even the buttons on your blouse or

shirt, owe their existence in their current form to Injection Moulding. Outside of

our homes injection moulded products are still all around us – the car, bus or train

you ride to work, school or college is full of injection moulded components and

whatever you do, there’s a good chance that you will spend a large portion of your

day tapping the injection moulded keys of an injection moulded computer. At the

end of the day, many of us watch television screens that are encased in injection

moulded plastic; often changing the channels with the injection moulded remote

control that we hold in our hands. Even when we go to bed at the end of the day,

if we look at the switch we use to turn out the light, whether it is on the wall, or in

the lamp on the bedside table, or screwed to the head board; it is a piece of

injection moulded plastic.

Injection Moulding is an important part of our everyday lives, our world

would be very different without it and product designers need to know about it;

they will use it many times during their careers.

Injection Moulding is the process of heating plastic granules to melting point

before injecting them at high pressure through a nozzle into a mould. When the

plastic cools the mould is opened and the newly formed plastic part is removed.

Injection moulding is a major processing technique for converting

thermoplastic materials to useful end products. Whereas the domestic and low

value and low performance commercial items are generally moulded with

conventional and commodity plastics. On the other hand, the industrial

components and engineering articles are being gradually replaced by so called high

performance engineering plastics.

Injection moulding may be described as a batch process, the machine

operating cycles. The brief description of an simple operation without any

problems. Whereas this is far from being the true situation. The collaborative inter

dependence of questions and demands a high degree of technical ability and above

ability. Considerable progress has been made in recent days in the construction of

advance moulding machines, moulds and modified injection moulding methods.

This enables mouldings to be made to very close tolerance, improve the quality of

the mouldings and economical production costs.

1.3.1Types Of Injection Moulding Machine:

1.3.1.1 Plunger injection moulding machine:

Fig 1.1 plunger injection moulding machine

The earlier and simpler type of machine used a heating barrel to soften and

melt the plastics material and a reciprocating ram to inject the material into the

mould.

1.3.1.2 Screw type machine:

Fig 1.2 screw type machine

In the single screw machine, an Archimedean screw is used instead of a

plunger. The screw rotates in the barrel, carrying the plastics material along its

flights to the nozzle end. As the softened material accumulates, it forces the screw

backwards against a pressure pad. When sufficient material to fill the mould has

accumulated, the screw stops rotating. To fill the mould, pressure is applied to the

screw through the pressure pad, causing it is move forward in the barrel and

displace the fluid material through the nozzle into the mould, the distance the

screw travels and hence the amount of fluid material fed into the mould is

regulated by means of limit switches. It is not necessary therefore to meter the

amount of material passing from the feed hopper to the barrel. There is however

the possibility of fluid material passing back along the screw flights but this is

usually avoided by fitting a backflow stop valve on the tip of the screw.

1.3.1.3 Pre plasticizing machine:

The screw plasticizing principle is sometimes used in two barrel machine.

The screw feeds solid granules along a heated plasticizing barrel into an injection

barrel, from which the melt is forced into the mould by means of a plunger, a non

return valve prevents fluid material from passing back into plasticizing barrel. The

plasticizing barrel can be either parallel, with or at an angle to the injection barrel.

1.4 MOULD:

Mostly the plastics products are not produced in a small quality but used to be

produced in large quantities. That means the mould should last longer to produce

more number of components. For this the mould must be made out of good grade

of steel, heat treatment must be given for the core and cavity and the other moving

parts to withstand the wear and tear the mould must be properly constructed with

proper alignment and matching with the mould parts etc.

The mould is made for a particular product with simple and straight forward

design, fabricated with proper mould material, heat treatment with proper concepts,

it is best assured that the mould will give consistent product for longer period and

the product will be readily accepted in any market local or international.

1.4.1 Types of Mould:

Injection moulds are divided into various types depending upon the

moulding shape and size, type of gate, no of impression and the machine to be

used.

1.4.1.1 Two plate mould:

Fig 1.3 two plate mould

This is a simple mould which may be single impression or multi impression

mould. The (gating) feed system will be side grated. This type of mould will have

only one daylight where the mouldings and feed system will be on the same

parting line.

1.4.1.2Three plate mould:

Fig 1.4 three plate mould

This type of mould will have two daylights. When a moulding has to be

gated at the back of cavity and is a multi impression mould, or when a single

impression mould id gated at more than one point from the cavity the mould will

be a three plate type of mould. That is, the feed system will be in between the fixed

half and the floating half. The mould parting line will be between the floating

assembly and moving half of the mould. The ejection of the moulding will be on

the parting line where as the ejection of the moulding will be on the parting line

where as the ejection of the feed system will be between the fixed half and floating

assembly. This type of mould requires careful design of various functional parts of

the mould.

1.4.1.3 Split mould:

Two mould components having continuous external undercut, example

the cavity is split into two pieces. To facilitate the ejection on the moulding the

splits (cavity salves) are required to be moved perpendicular to the axis of the

mould opening. This is achieved by providing suitable cams of hydraulic

cylinders. The design of this type of mould required careful consideration and the

location, movement and alignment of the splits. The ejection mechanism also to

be carefully designed to prevent folding of the ejector pin with splits.

1.4.1.4 Delayed action mould:

Fig 1.5 delayed action mould

Some mouldings warrant the movement of the splits to the delayed for the

certain amount of opening of the mould. This is the splits will be in a closed

condition (delayed) till the mould opens to release the interfering member for the

movement. This type of mould may use cams or sequenced hydraulic cylinders to

the operation of the mould.

1.4.1.5 Runner less mould:

The aim in any manufacturing process is to keep the amount of waste to a

minimum, in injection moulding this means that no material must be lost between

the nozzle and the mould cavity. To bridge this distance one makes of melt flow

way systems which convey the plastic melt from nozzle to the gate

1.5 MOULD MATERIAL SELECTION CRITERIA:

Greater care is necessary whenever we choose the material for the various

parts of the mould. Particularly core, cavity and other melt flow areas must be a

toughened steel which should be heat treated. Similarly guided members, actuating

member level in order to get a good quality moulding with a long service life of the

mould. Generally the selection of the mould materials is based upon the production

requirement of the mouldings id based upon the production requirement of the

mouldings. For shorter run, mild steel is recommended and for a medium run pre

hardened steel is used but for a larger production run, hot die steel with suitable

recommended hardness is essential for long life and also for good quality of the

moulding. The moulding surfaces should be polishes smooth in order to get a good

finish and free ejection of the moulding. Electro plating/chromium plating of core

and cavity may be done after polishing according to the finish required and also the

type of polymer used.

In order to get more consistent, elegant and precision injection, compression

or blow moulded parts for any applications, three factors have to be critically

considered

They are

The moulding machine

The material

The mould

Moulding machine:

The machine which is used for producing injection moulded parts plays a

very important role. The machine must be accurate in giving correct injection

pressure, moulded temperature control system, proper alignment between the two

platen etc. A good injection moulding machine will definitely give consistent good

quality products. The different types of plastics materials used for producing

various products must be of good graded quality. If substandard plastic raw

materials are used good quality plastic components are also assured.

The most important role is played in getting quality and precision moulded part

is by the mould designs and fabrication of mould for particular product. The above

three factors the machine, the material and the mould (3M) are inter related. If

anyone is not proper it is best assured that we will not get any quality moulded

components.

Mould material:

Mould material uses are Good grade of mild steel for bolster or the mould

housing is used for the manufacture of core and cavity special alloy steel are used.

They are hot die steels with 5% chromium En8, En24, En30B, H13, H12, P20 etc.

High carbon and high chromium steel is also used for the manufacturing of core

and cavities. Pre hardened steel is also used (Hardness level) for 30-32RC core and

cavities without heat treatment.

In the case of producing plastics products to have better appearance,

elegance on the products the cavities have to be polished to mirror finish. This

mirror finish or high polish of the cavity can be obtained by two ways that is by

way of electroplating and surface or by using superior quality of alloy steel for

making the cavities.

Mould:

The mould polishing not only gives super finish on the product but helps the

material (plastic) to flow in to the cavity with less pressure and also ejection of the

product from the cavity or core will be very easy without straining the ejection

system provided in the mould.

In order to get good moulded components the mould must function well with

all systems, provided adequately

The systems are:

Feed system

Cooling system

Ejection system

Every care must be taken in providing the above systems effectively in the

mould. All the above systems must be carefully studied at the design stage and

incorporated. Once the mould design is completed, the manufacturing of the mould

must be exactly to the design provided and all the parts (mould elements) including

the core and cavity must be made according to the dimension. Through checking

must be carried out at every stage. Never take a short cut while making the mould,

every part in the mould has to be done as per the requirement. Short cuts will lead

to difficulties at the time of finishing the mould.

1.6 INJECTION MOULDING TECHNIQUE/PROCESS:

The injection moulding machine comprises of a locking unit for keeping the

mould firmly closed against high injection pressure and an injection unit for

heating and plasticizing the material and injection it into the mould. The locking

unit holds the mould closed for a predetermined time to allow the muolded article

to cool and solidify. In the moulding cycle of the plunger injection moulding

machine, the injection mouilding time is generally not more than few seconds,

whereas the dwell period to the solidification of the sprue or on the gate requires

several seconds. The decisive element of the cycle is the cooling time to ejection,

which can take several minutes with large mouldings.

1.7 APPLICATION OF INJECTION MOULDING :

Injection moulding is a manufacturing technique for making parts from

plastic material. Heated, fluid plastic is injected at high pressure into a mould,

which is the inverse of the desired shape. The steel or aluminum mould is

machined with the contours of the final product. Injection moulding is used for

create a variety of parts, like plastic milk cartons, containers, bottle caps,

automotive dashboards, pocket combs, and most other plastic products available

today. Injection moulding is the most common method of part manufacturing. AC

drives will commonly be used to power the hydraulic oil pressure pump for

operating the mould works of an injection-moulding machine. Servo drives can be

used to operate the injection screw, as precision control is often required for the

injection step. Significant energy savings are often realized by replacing hydraulics

with electric drive systems on injection moulding machines.

Injection moulding is used to create many things such as wire spools,

packaging, bottle caps, automotive dashboards, pocket combs, and most other

plastic products available today. Injection moulding is the most common method

of part manufacturing. It is ideal for producing high volumes of the same object.

Some advantages of injection moulding are high production rates, repeatable high

tolerances, the ability to use a wide range of materials, low labour cost, minimal

scrap losses, and little need to finish parts after moulding. Some disadvantages of

this process are expensive equipment investment, potentially high running costs,

and the need to design mouldable parts

1.8 METHODOLOGY:

Fig 1.6 methodology

Development of low cost injection moulding machine

Survey of injection moulding machine

Selection of low cost injection moulding machine

Design of various components

Drafting and modeling

Fabrication of various components

Implementation

Conclusion

CHAPTER 2

LITERATURE REVIEW

From the tailor made training programmed on plastics for engineers book we collect information about

Introduction to plastic process

Fundamentals of polymers

Thermoplastic materials

Mould fabrication

Mould material selection

2.1 INTRODUCTION TO PLASTIC PROCESS:

Injection moulding is a major processing technique for converting

thermoplastic materials to useful end products. Whereas the domestic low value,

low performance commercial items are generally moulded with conventional and

commodity plastics. On the other hand, the industrial components and engineering

articles are being gradually replaced by so called high performance engineering

plastics.

Injection moulding may be described as a batch process, the machine

operating cycles. The brief description of an simple operation without any

problems. Whereas this is far from during true situation. The collaborative inter

dependence of questions and demand a high degree of technical ability.

Considerable progress has been made in recent days in the construction of advance

moulding machines, moulds and modified injection moulding methods. This

enables mouldings to be made to very close tolerance, improve the quality of the

mouldings and economical production costs.

2.2 FUNDAMENTALS OF POLYMERS:

Polymers are a large macromolecule built up of repetition of small and

simple chemical units called monomers. Polymer can be of long chain molecules

or branched long chain molecules or molecules of interconnected three

dimensional networks. The repeat unit of the polymer is equivalent or nearly

equivalent to the monomer or starting material from which the polymer is formed.

2.3 THERMOPLASTIC MATERIALS:

The term plastics refer to a vast range of materials based on macro molecular

organic components. Traditionally plastics have been divided into two major

classes according to their behavior towards heat and consequently this subdivision

is primarily one based on process ability. It must, however, be borne in mind that

difference in properties will also result from the differences in structure. One

clarification attempts to categories plastic on the basis of the chemical structure of

the polymer constituent. Sometimes based on the tonnages of plastics used,

references also made to ‘commodity’ or large-huge plastics and specialty polymers

bit this basis is purely commercial and naturally is bound to vary with time

depending on usage pattern.

2.4 MOULD FABRICATION:

The machine which is used for producing injection moulded parts plays a

very important role. The machine must be accurate in giving correct injection

pressure, moulded temperature control system, proper alignment between the two

platen etc. A good injection moulding machine will definitely give consistent good

quality products. The different types of plastics materials used for producing

various products must be of good graded quality. If substandard plastic raw

materials are used good quality plastic components are also assured.

The most important role is played in getting quality and precision moulded

part is by the mould designs and fabrication of mould for particular product. The

above three factors the machine, the material and the mould (3M) are inter related.

If anyone is not proper it is best assured that we will not get any quality moulded

components.

2.5 MATERIAL SELECTION CRITERIA:

A smaller share of the total plastics production although still measured in the

billions of pounds is reserved for engineering plastics. These class of plastic

materials are capable of High loading for long period of time at elevated

temperature in adverse environments. Behave in a predictable manner when

subjected to design techniques and formulas.

2.6 PLANTS VISITED:

2.6.1 L&T demag plastic division :

L&T Plastics Machinery Limited (formerly L&T-Demag Plastics Machinery

Limited) was a Joint Venture company between Larsen & Toubro Limited, India’s

largest engineering conglomerate and Demag Plastics Group GmbH, Europe

largest manufacturer of injection moulding machines.

As a leader in the manufacture of injection moulding machines in India since

1992, L&T machines are of the finest quality. The performance of our machines

has consistently provided unparalleled results which directly reflect in part quality

and cost effectiveness of the moulding. L&T machines are manufactured at the

state-of-the-art new manufacturing facility in Chennai that is fully equipped for

producing machines in sizes up to clamping force of 1000 Metric Tons. The

factory has advanced facilities for research & development. L&T Injection

Moulding Machines due to its consistent performance and high productivity has

established itself as a preferred choice with plastic moulders. In March 2009, L&T

bought the stake held by Demag in the joint venture company and has become a

fully owned subsidiary of L&T.

Products produced:

Plastic injection moulding machine, plastic cap moulding system, perform

moulding system, packaging moulding machine, house hold articles moulding

machine.

From this visit we collect information about the working of various types of

automatic moulding machine from various divisions.

2.6.2 SA plastics:

From this visit, we get the information about various types of machines, they

are listed below

Manual plunger injection moulding machine

Semi automatic plunger injection moulding machine

Manual plunger injection moulding machine:

In manual injection moulding machine the operation of the injection and the

clamping are done manually.

Semi automatic plunger injection moulding machine:

In this machine injection of plastic is done by hydraulic cylinders and the

other operations are done manually.

Products produced:

Water tap, water tank, hand shower, union etc.

CHAPTER 3

SELECTION OF LOW COST PLASTIC INJECTION MOULDING MACHINE AND MATERIAL

3.1 REASON FOR SELECTION:

The injection moulding machine which are available today are of lower

and higher tonnage machines. In higher tonnage machines injection pressure is

very high and also we require higher clamping force. This type of machine is

required for high end application and the cost of machines are also very high. This

machine are not required for producing components that can be made manually,

and also to stress the importance of recycling process we decided to fabricate low

cost plastic injection moulding machine. In this plastic injection moulding machine

we can produce components which require very less injecting pressure clamping

force and low processing temperature.

Fig 3.1injection moulding machine

3.2 COMPONENTS OF INJECTION MOULDING MACHINE :

3.2.1 Injection unit :

Rack and pinion :

The rack and pinion is used for applying the force which is required for

injecting the the molten plastic material into the die. The force is applied in the

pinion and then transferred to the rack which acts as a plunger.

Barrel:

The barrel acts as a temporary storage where the plastic material is melted.

The barrel contains the hopper and spring. The hopper is used for supplying

material to the barrel, whereas the spring is used for automatic retraction of

plunger.

3.2.2 Heating unit :

In this unit the plastics materials that is added to the barrel is heated by a

heater. The temperature of the heater is controlled by a control box. The heater

heats the barrel which in turn heat the plastics inside the barrel.

3.2.3 Clamping unit:

The clamping unit is mainly used to clamp the mould to the center of the

nozzle. The clamping unit does not allow any movement of the mould during

injection of molten plastics into the mould. It acts against the injection pressure

applied by the injection unit.

3.2.4 Mould:

The mould consists of core and cavity. Cavity is the main part where the

molten plastics fill inside and take the required shape of the mould. Mould consists

of a runner through which the molten plastics enter the cavity. The molten plastics

which stays in runner is removed as waste.

3.3 SELECTION OF MOULD MATERIAL

Material used : EN8MS

EN stands for "Euro-Norm"

Tensile properties can vary but are usually between 500-800 N/mm2

Composition :

C 0.35 - 0.45%;

Si 0.05 - 0.35%;

Mn 0.6 - 1.0%;

S, P < 0.06%;

Yield Stress x 10^6 Pa: 530;

Tensile Stress ,MPa: 660;

Elongation %: 7.

Selected mould material composition :

C. 0.40%

Si. 0.25%

Mn. 0.80%

S. 0.015%

P. 0.015%

MATERIAL INJECTION TEMPERATURE °F

MOULDING PRESSURE P.S.I

POLYSTYRENE(GENERAL PURSOSE)

350-550 10000-25000

Polystyrene (rubber modified ) 375-500 10000-25000Polyethylene (low density) 300-500 10000-25000Polyethylene (high density) 330-530 10000-15000Polypropylene 375-600 10000P.V.C (plasticized) 320-400 10000-25000P.V.C (rigid) 300-400 15000-40000Cellulose acetate 350-440 8000-30000Cellulose acetate butyrate 350-440 8000-30000Polymethylemethacrylate 350-475 10000-20000Nylon 520-650 10000-20000Acrylonitrile butadiene styrene (ABS)Styrene acrylonitrilePolycarbonateAcetal

3.4 MATERIALS CONSIDERED :

3.4.1 High Density Polyethylene:

Hdpe is made by the polymerization of ethane that is ethylene (CH2 = CH2)

in the presence of catalyst.

It is made from petroleum or natural gas feed stocks.

The properties and applications of HDPE vary wide ranges depending on the

molecular weight, the method of manufacture, and differences in structure

and density.

Table 3.1 Properties of Thermoplastic Materials

Characteristics of HDPE:

They have excellent resistance to solvents and chemicals.

They are tough and flexible over a wide range of temperature.

They are non toxic.

They posses good electrical insulation properties.

It is stronger and high tensile strength.

It is made by low pressure technique.

It is harder and more opaque.

It has a high degree of crystallinity.

Density : 0.941-0.959g/cm3.

Specific gravity : 0.94-0.965.

Applications:

Films made from HDPE are widely used for packaging and lamination of

natural fibers.

It is also used for the manufacture of industrial components.

It is used for cable coating and insulating pipes.

Pipes made from HDPE are used for transporting water and various other

chemicals.

Typical applications of HDPE include flexible bottles, toys, buckets, etc.

3.4.2 Polypropylene:

Polypropylene is formed from the monomer propene that is propylene(CH2 =

CH - CH3).

This is also belongs to the group of polyfins like polyethylene and is

manufactured by the low pressure process.

It is similar to HDPE but its mechanical properties make it more suitable for

moulded parts than polyethylene.

Characteristics of polypropylene:

They are stiffer, harder, and often stronger than polyethylene.

They have excellent fatigue resistance and a higher use temperature.

They are lighter in weight.

They have good chemical and thermal resistance.

They are relatively low resistance to ultra-violet light.

It has high temperature resistance in view of higher melting point.

It is reasonably economical.

It is commonly recycled.

Density : 0.855-0.946g/cm3.

Specific gravity : 0.90-0.91.

Applications:

polypropylene is resistant to fatigue, most plastic live hinges, such as those

on flip-top bottles, are made from this material.

Very thin sheets of polypropylene are used as a dielectric within certain high

performance pulse and low loss

High-purity piping systems are built using polypropylene.

Polypropylene is used in washing machines, vacuum sweepers, brief and suit

cases etc.

It also include low cost semi rigid moulded products such as house wars, car

interior components, bottle caps, extruded pipes, carpet fibers, etc.

3.4.3 Mild steel :

Mild steel is a carbon steel typically with a maximum of 0.25% Carbon and

0.4%-0.7% manganese, 0.1%-0.5% Silicon and some + traces of other elements

such as phosphorous, it may also contain lead (free cutting mild steel) or sulphur .

Properties :

The maximum limit is 2 % carbon in the manufacture of carbon steel, the

proportions of manganese (1.65%), copper(0.6%) and silicon (0.6%) are

fixed, while the proportions of cobalt, chromium, niobium, molybdenum,

titanium, nickel, tungsten, vanadium and zirconium are not.

Carbon makes mild steel stronger and stiffer than other type of steel

The calculated average industry grade mild steel density is 7.85 gm/cm3.

It is not brittle

Mild steel is the cheapest and most versatile form of steel and serves

every application which requires a bulk amount of steel.

3.4.4 Stainless steel

Stainless steel does not stain, corrode, or rust as easily as ordinary steel (it

stains less, but it is not stain-proof). It is also called corrosion-resistant steel There

are different grades and surface finishes of stainless steel to suit the environment to

which the material will be subjected in its lifetime. Stainless steel is used where the

properties of steel, and resistance to corrosion are required.

Properties:

stainless steel is the ability to maintain the same surface, colour and

structure i.e. its corrosion resistance.

Pure iron is the main element of stainless steel. Pure iron is prone to

rusting and is highly unstable, as it is extracted from iron ore. Rusting of

iron is due to its reaction with oxygen, in the presence of water.

Chromium forms a transparent and passive layer of chromium oxide,

which prevents mechanical and chemical damage.

CHAPTER 4

DESIGN OF VARIOUS COMPONENTS

4.1 INTRODUCTION :

Engineering design is the process of devising a system, component, or

process to meet desired needs. It is a decision making process in which the basic

sciences and mathematics and engineering sciences are applied to convert

resources optimally to meet a stated objective. Among the fundamental elements of

design process are the establishment of objectives and criteria, synthesis, analysis,

construction, testing and evaluation. The various components that are required to

be designed are listed below.

Plunger force

Pinion

Spring

Heating coil

Clamping force

Mould

4.2 DESIGN PROCEDURE ADOPTED:

4.2.1 Design of spring:

Calculation of maximum deflection:

δmax = L - Ls

Calculation of axial load on spring:

δmax =

Calculation of helix angle:

tanα =

Calculation of shear stress factor:

ks = 1+

Calculation of maximum shear stress:

τ = ks

calculation of spring stiffness:

K =

4.2.2 Design of pinion:

Selection of material

Calculation of pitch circle diameter:

Pc =

Calculation of tangential force:

F =

Calculation of power:

P = Ft × v

Calculation of transmission ratio:

i =

calculation of module:

Ft = where v =

Calculation of static load:

Fs = πm[σb]by b = 10module from PSG data book pg.no.8.50

Calculation of b, d, and v:

b = 10m

d = mZ1

v =

Calculation of accurate Fd using bukinghams : from PSG data book

pg.no.8.51

Check for beam strength:

Fs >= Fd

If not design is not satisfactory by increasing the face width or by increasing the module or by increasing by reducing dynamic load.

Calculation of maximum wear load:

Fw = d1qkb k = 0.5 to 1 from PSG data book pg.no.8.51

Check for wear load :

Fd < Fw

4.2.3 Design procedure for heating coil:

Calculation of heat absorption rate:

Heat absorption rate = ηcoil × heat generation rate

Calculation for time of melting:

Heat absorption rate =

Calculation of effectiveness of the coil:

By experimental observation the time taken for melting is noted

and by using the same formula as mentioned above. The effectiveness of

the coil is calculated.

4.2.4 Design of clamping force and torque:

Calculation of injecting pressure:

Pmax =

Calculation of force developed in the cavity:

Fcavity = Pmax × area of the cavity

Calculation of helix angle of the screw:

tanα = d =

Calculation of angle of friction:

tan Ø = μ the coefficient of friction for screw jack or thread

is assumed as 0.15 to 0.3

Calculation of load applied on the circumference of the screw:

Pscrew = Wclamp × tan(α+Ø) ×

Calculation of torque exerted on the screw:

T = Pscrew ×

Calculation of torque exerted on the wheel:

T = Pwheel ×

4.2.5 Design of volume of component:-

Calculation of total mass of the product:

Calculation of volume of the material:

Density =

4.3 KNOWN PARAMETERS:

Spring:

Pitch = 20mm

Diameter of the coil = 6.36mm

Mean diameter of the coil = 57.3mm

Length of the coil = 45mm

Solid length of the coil = 24mm

Pinion:

Number ot teeth on pinion = 11

Number of teeth on wheel = 22

Diameter of the pinion = 35.6mm

Pinion speed = 10rpm

Heating Coil:

Power of the heater = 500watts

Melting temperature of the plastics = 60ºc

Atmospheric temperature = 25ºc

Efficiency of the coil = 70% assume

Experimentally Observed:

Time taken for melting the plastics = 2sec

Clamping Force:

Plunger area = 19.098mm

Diameter of the cavity = 40mm

Pitch of the screw = 6mm

Outer diameter of the screw = 115mm

Inner diameter of the screw = 110mm

Length of the pinion handle = 220mm

Mould:

Experimentally Observed :

Weight of the product = 3.082gm

4.4 Materials Properties For Various Components:

Pinion:

Mild steel

Maximum bending stress = 140 N/mm2

Maximum compressive stress = 500 N/mm2

Poly Propylene:

Specific heat capacity = 2900 J/kg k

Density = 0.855 – 0.946 g/cm3

High Density Poly Ethylene:

Specific heat capacity = 2100 - 2700 J/kg k

Density = 0.941 – 0.959 g/cm3

Stainless steel

Modulus of rigidity = 70 kn/mm2

4.5 DESIGN OF PINION:

1. To find pitch circle diameter:

Pc =

= π*35.6/11

d1 = 10mm

2. To find velocity:

V =

=

V = 5.235*10-3m/sec

3. To find the tangential force:

F =

Ft = F*cosØ Ø = 20°

= 450*cos20°

Ft = 422.86 N

4. To find the total power:

P = Ft*V

= 422.86*5.235*10-3

P = 2.213 W

5. Selection of material:

Mild steel C45

For C45 mild steel

b = 140 N/mm2 from data book pg.no = 8.5

c = 500 N/mm2

6. To find transmission ratio:

Z1 = 11 , Z2 = 22

Z2 = i*Z1

I= 22/11

I = 2

7. Calculation of module :

Ft =

V =

=

V = 5.759*10-3 m/s

Ft = *1.25

422.86 =

m = 1.136

m ~ 2

8. Calculation of Fs :

Fs = πm[ b ]by from data book pg.no = 8.50

y = 0.154 –

y = 0.154 –

= 0.0711

= π*2*20*140*0.0711

Fs = 1250.856 N

9. Calculation of b, d, and V:

b = 10m

b = 20mm

d = mZ1

d = 22mm

V =

=

V = 0.0115m/sec

10.Calculation of accurate Fd by using buckinghams:

Fd = Ft + from data book pg.no = 8.51

For c value from 8.53 table 41

For 20º full depth cteel and steel the error in action value is 11860e

For e value 2mm module and carefully cut gears e=0.025

The ‘c’ value is

c =11860*0.025

= 296.5 N/mm

= 296.5 kgf/cm

Ft =

=

= 192.17 N

Ft = 19.2173 kgf

Vm = 0.0115m/sec

= 0.0115*60

= 0.60m/min

b = 20mm

b = 2cm

Fd = 19.2173 +

= 21.096979 kgf

Fd = 210.96 N

Satic load is greater than dynamic load

So design is safe.

11.Calculation of wear load:

Fw = d1qkb (assume k=0.68)

Q =

=

= 1.333

= 22*20*1.333*0.68

Fw = 398.8336 N

Wear load is greater than dynamic load

So design is safe.

4.6 VOLUME OF THE COMPONENT:

The mass of the product = 3.64gm

Shrinkage and other losses = 5% of the mass

The total mass of the product = 3.64*(5/100)+3.64

Total mass of the product =3.82gm

For PP the range of density is = 0.855-0.946g/cm3

For maximum density the volume is = 3.822/0.946

Volume of polypropylene =4.04cm3

For HDPE the range of density is = 0.941-0.959g/cm3

For maximum density the volume is = 3.822/0.959

Volume of HDPE = 3.985cm3

4.7 HEATING COIL CALCULATION :

Total Power Consumed by the heater = 500W

Rate of heat generated by the coil = 500 J/sec

Rate of heat absorbed by the plastic is theoretically equal to heat

generation

But while transferring of heat there may b losses ,hence the heat

absorption rate by the plastic is always less than the heat generation

rate of the coil

Let efficiency of the coil is assumed as 70%

Heat absorption rate by the plastics = ᶯcoil * heat generation rate

= 0.7*500

= 350 J/sec

Heat absorbedtion rate =

350 =

Time for melting =

Time for melting = 1.1078sec

Expected time of melting t = 1.1078sec

4.7.1 Experimental observation:

Time of melting = 2sec

Mass of the finished product including losses = 3.82gm

Heat absorbedtion rate =

=

= 193.865 J/sec

Heat absorption rate by the plastics = ᶯcoil * heat generation rate

193.865 = ᶯcoil * 500

Effectiveness of the coil melts the plastic = 38.77%

4.8 DESIGN OF SPRING :

P = 20 mm

d = 6.36 m

D = 57.3 mm.

C =

=

C = 9

ks = 1 + = 1 +

ks =1.05

w.k.t the max deflection is the difference of the total length and solid

length of the spring

δmax = L-Ls

δmax = 45-24

δmax = 21mm

δ =

(For Stainless steel,G=70 kn/mm2)

21 =

Wmax =

Wmax = 456.58 N

Wmax = 45.658 kg

tan α =

=

α = 45.02

Maximum Shear Stress :

τ = Ks *

τ = 1.05*

τ= 271.912 N/mm2

Spring stiffness

K =

=

K = 21.742 N/mm

Total plunger force to be given is 456.58 N or 45.658 kg

4.9 TORQUE CALCULATION:

Fcavity = Pmax * *D2

Pmax =

=

Pmax = 1.59 N/mm2

Pmax =1.59*106 N/m2

Fcavity = 1.59*106 *((π/4)*(0.04)2)

Fcavity = 1998.052 N

Fcavity = 199.8052 kg

Pscrew = Wclamp* tan (α +Φ)

tan α =

= d

πDi = 110 πDo = 115

Di = 35.014 mm Do= 36.6 mm

Di = 0.035 mm Do = 0.036

d =

=

d = 0.0358 m

Pitch = 6 mm

= 6*10-3 m

tan α =

α= 3.053˚

tan Φ = 0.3

Φ =16.7 ˚

Pscrew = Wclamp * tan (α+Φ)

= 1998.052*tan (3.053 +16.7)

Pscrew = 717.492 N

Pwheel = Wclamp *tan (α+Φ) *

Dwheel = L*2

Dwheel = 220*2

Dwheel = 440 mm Dwheel = 440 *10-3 m

Pwheel = Wwheel * tan (α+Φ) *

= 717.492* tan (3.053+16.7) *

Pwheel = 20.96 N

Total Torque excerted on the screw

T = pscrew *d/2

= 717.492 *0.0358/2

T = 12.84 N-m

Also total torque exerted on the wheel

T = Pwheel *

= 20.96 *

T= 4.6112 N-m

4.10 Specifications:

1. Maximum deflection δmax 21mm2. Maximum plunger force Wmax 456.58N3. Helix angle α 45.02º4. Spring stiffness K 21.742N/mm5. Maximum shear stress τmax 271.912 N/mm2

Table 4.1 for spring

1. Pitch circle diameter d 22mm2. Diameter of pinion D 44mm3. Module m 24. Center distance a 33mm5. No.of teeth on pinion Z1 116. No.of teeth on wheel Z2 22

Table 4.2 For pinion

1. Total mass of product m 3.82gm2. Volume of the mould

cavityV 4.04g/cm3

Table 4.3 For mould

1. Force developed in the Fcavity 1998.052

cavity2. Helix angle of the screw α screw 3.053º3. Torque exerted on the

screw Tscrew 12.84N-m

4. Torque exerted on the wheel

Twheel 4.6112N-m

5. Maximum pressure Pmax 1.59N/mm2

Table 4.4 For clamping force and torque

1. Expected time of melting T 1.1078sec2. Effectiveness of the coil η 38.77%

Table 4.5 For Heating coil

CHAPTER 6

FABRICATION OF VARIOUS COMPONENTS

6.1 L-BRACKET:

The plates are in the shape of C-section are cutted to the required

dimensions. The ends at which welding are to be done are surface prepared. The

plates are kept in the desired positions and then using arc welding process the

plates are welded. To give support to the section the

6.2 MOULD:

The work piece is mounted on the lathe machine. Then using facing

operation , the thickness of the work piece is reduced to the required dimension.

Then using the turning operation the work piece is turned to get the cavity of

required dimension. Then using surface grinding operation , The surface of the

work piece is made into a perfectly flat surface. Then engraving operation is done

to the required symbol and shape. Then using milling operation the milling is done

to get the runner of required dimension. Then using drilling operation, drilling is

done at the corners of the work piece and dowel pins are inserted in the drilled

holes.

6.3 ASSEMBLY:

The assembly considered in two different steps. The first is the asse mbly of

injection unit and the second is the assembly of clamping unit. Both the units are

assembled in L-bracket. The injection unit is assembled vertically and the

clamping unit is assembled horizontally. In the injection unit assembly, the rack

and pinion holder is mounted and fastened vertically so that the rack reciprocates

vertically. Then, the injection unit is mounted on the L-bracket vertically with the

help of injection unit holder. The hopper is screwed to the barrel of the injection

unit such that the spring is locked in between them. The clamping unit is fastened

to the L-bracket horizontally with the help of bolts.

6.4 INSTALLATION OF INJECTION MOULDING MACHINE:

The assembled injection moulding machine in mounted on the wooden table

and fastened to it. The process is done by drilling holes on the wooden table and

the L- bracket and fastened with the help of bolts and nuts. The power supply to

the heating coil is given through the temperature controller which controls the

supply and temperature of the heating coil. The injection moulding machine is

installed in such a way that operation or rotation of the pinion and clamp.

Conclusion:

Thus the development of low cost injection moulding machine has been

designed, fabricated, assembled, and installed. It has been tested successfully and

found that for the specified temperature of the plastic material and for 3.82gms of

input, the final output of the finished product was 3.64gms.

Recommendations for Future works:

There is a huge scope for future works by giving automation to the plunger

unit and to a great extent to the clamping unit a center locator can be placed so that

there is no problem of adjusting the center of mould and the injection nozzle. The

temperature controller can digitized to get the precise temperature control and

therefore increases the efficiency of the entire system.

Reference:

Introduction To Plastic Process:

By Mr. K.N. Raghu

Fundamentals Of Polymers:

By Dr. C. Brahatheeswaran

Thermoplastic Materials:

By Dr. K. palanivelu

Mould Fabrication:

By Mr. Fredric Moses

By Ms. Irene Suresh

Internet source

www.wikipedia.com

www.howstuffworks.com

www.youtube.com