CHAPTER1

INTRODUCTION

3

1.1 Fabrication

The polymer material are converted into plastics and used as tubes, sheets,

foams, rods, adhesives, etc., The theological properties, softening, tempering,

stability, the size and shape are important in describing the method. These

methods are different kinds of plastics. Broadly speaking the method may be

discussed under the following headings,

a. Moulding Process

b. Foaming Process

1.1.1. Moulding process:

In this process the plastics are fabricated under the effect pressure and

heat and both thermoplastics and thermosetting plastics may be starting materials.

Thermoplastics are produced by this method. In this the material is softened by

heating and the hot softened plastic is forced under high pressure into the mold,

when it is set by cooling and the mold is.

1.1.2 Foaming process:

This involves the blowing of a volatile organic liquid, which is entrapped into a

polymer network resulting in the formation of foamed plastics. Foamed

polystyrene are produced in this process.

1

CHAPTER2

2.1 Components

The main components of the pneumatic injection moulding

machine are,

• Pneumatic Double acting Cylinder

• Hooper

• Barrel

• Heating Coil and regulator

• Direction control Valve

• Flow control valve

• L-Angle

• Nozzle

• Die and

• Hose connectors

a. Pneumatic Double Acting

Cylinders:

A double acting cylinder is employed in control systems with the full

pneumatic cushioning and it is essential when the cylinder itself is required to

retard heavy messes.

This can only be done at the end positions of the piston stock. In all

intermediate position a separate externally mounted cushioning derive most be

provided with the damping feature.

The normal escape of air is out off by a cushioning piston before the end

of the stock is required. As a result the sit in the cushioning chamber is again

2

compressed since it cannot escape but slowly according to the setting made on

reverses. The air freely enters the cylinder and the piston stokes in the other

direction at full force and velocity.

b. Hooper:

The hopper is used to pour the plastic raw materials in to the barrel.

c. Barrel:

The barrel is used to hold the molten and unmated plastic raw materials.

d. Heater and Regulator

The heating coil is used to melt the plastic raw materials to the molten

Form which is inside the barrel

The heating coil regulator is used to regulate the temperature of heating coils

according to the type of plastic raw materials used.

e. Direction Control Valve:

To control the to and fro motion of cylinder, the fluid energy has

to be regulated, controlled and reversed with a predetermined sequence in a

pneumatic system.

Similarly one may have to control the quantity of pressure and flow

rateto generate the desired level of force and speed of actuators. To achieve these

functions, valves are used. Valves are fluid power elements used for controlling

and regulating the working medium.

The main functions of the valves are,

• Start and stop the fluid energy

• Control the direction of flow of compressed air

• Control the flow rate of the fluid

• Control the pressure rating of the fluid

3

f. Flow Control Valve:

These are used to control the rate of flow of a fluid through the valve.

A directional control valve on the receipt of some, external signal, which might be

mechanical, electrical or a fluid pilot signal, changes the direction of stops, or

starts the flow of fluid in some part of the pneumatic/hydraulic circuit. They can

be used to carry out such functions as:

1. Controlling the direction of motion of an actuator

2. Selecting alternative flow paths for a fluid.

3. Stopping and starting the flow of fluid

Purpose: This valve is used to speed up the piston movement and also it acts as a

one way restriction valve which means that the air can pass through only one way

and it can’t return back.

By using this valve the time consumption is reduced because of the faster

movement of the piston.

g. L-angle:

Mild steel ‘L’ type angle is used to fabricate the frame to mount

the all the parts of the injection molding unit.

h. Nozzle:

The nozzle is used to inject the molded plastic material into the die.

i. Die:

The die is used to produce the required product. By using different

Types of die different products can be formed.

4

j. Hose connector:

In our pneumatic system there are two types of connectors used; one is

the hose connector and the other is the reducer.

Hose connectors normally comprise an adapter (connector) hose nipple and

cap nut. These types of connectors are made up of brass or Al or hardened steel.

Reducers are used to provide inter connection between two pipes or hoses of

different sizes. They may be fitted straight, tee, “V” or other configurations.

These reducers are made up of gunmetal or other materials like hardened steel etc.

Hoses used in this pneumatic system

are made up of polyurethane. These hoses can with stand at a maximum pressure

level of 10 kg/cm2.

2.2 Technical Data

2.2.1 Double Acting Pneumatic Cylinder

Stroke length : Cylinder stoker length 160 mm = 0.16 m

Piston rod : 18 mm = 18 × 10¯³ m

Quantity : 2

Seals : Nitride (Buna-N) Elastomer

End cones : Cast iron

Piston : EN – 8

Media : Air

Temperature : 0-80 º C

Pressure Range : 8 × 105 N/m²

5

2.2.2 Solenoid Valve

Size : 0.635 × 10 ¯² m

Part size : 0.635 × 10 ¯² m

Max pressure range : 10 × 10 ⁵ N/m²

Quantity : 2

2.2.3 Flow Control Valve

Port size : 0.635 × 10 - ² m

Pressure : 0-8 × 10 ⁵ N/m²

Media : Air

Quantity : 1

Max working pressure: 10 × 10 ⁵ N/m²

Temperature : 0-100 ºc

Fluid media : Air

Material : Brass

2.2.4 Hoses

Max pressure : 10 ×10 ⁵ N/m²

Outer diameter : 6 mm = 6 × 10 ¯ ³m

Inner diameter : 3.5 mm = 3.5 × 10 ¯ ³m

6

2.3General Machine

Specifications

a. Drill unit

Short capacity : 0.635 × 10 -² m

Barrel diameter (ID) : 40 mm = 40 × 10¯ ³m

b. Clamping unit

Clamping : Auto clamping

Max Clamping Size : 100 mm = 0.1m

c. Pneumatic unit

Type of cylinder : Double acting cylinder

Type of valve : Flow control valve & solenoid valve

Max air pressure : 8 × 10⁵ N/m²

d. General unit

Size of machine (L x H) : 0.4 m x 0.8 m

Weight : 441.45 N

7

2.4 Design Calculation

Pressure applied :8 × 105N/m²

Diameter of piston rod (D)

Area of cylinder (A)

:

:

4 × 10-2 m

12.56 × 10⎯⁴ m²

Force exerted in the piston (F) : Pressure applied x Area of cylinder.

= 8 N/m2 ×12.56 × 10-4m2

= 10.48 × 102N

8

2.5 DESIGN DRAWINGS

FIG 1

L-BEAM

9

FIG 2

10

BARREL

FIG 3

11

SUPPROT FOR BARREL

FIG 4

12

SUPPORT FOR VICE

FIG 5

13

ROTATING HANDLE FOR FIXTURE

FIG 6

14

PNUEMATIC CYLENDER

FIG 7

15

ASSAMBLY VIEW

FIG 8

16

LAYOUT DIAGRAM

17

CHAPTER-3

FACTORS INFLUENCING THE DESIGN

The following are the factors influencing the fabrication work,

a. Working Stress

b. Working strain

c. Elasticity

d. Hooke’s Law

e. Bulk Modulus

f. Poisson Ratio

g. Factor of Safety

a. Working Stress:

The internal resistance must be equal to the external load if the body is to be in

equilibrium. This internal resistance per unit area is called intensity of stress or simple

stress.

Stress = Internal resistance / Area of cross section.

b. Working Strain:

The deformation per unit length is called strain. Strain has no unit since it is only a

ratio. Strain = Change in length / Original length

c. Elasticity:

The property of a material body to regain its original condition on the removal

of the deformation forces is called elasticity.

18

d . Hooke’s law:

It states that when a material is loaded with in its elastic limit the stress is proportion

to the strain.

Stress / Strain is a constant.

e. Bulk modulus:

The ratio of the change in the volume to the original volume of the body is known

as the volume strain or the bulk strain.

The ratio of the bulk stress to the bulk strain of a body is called the bulk modulus.

f. Poisson’s ratio:

With in the elastic limit the lateral strain bears a constant ratio with the linear

strain. The ratio is called the Poisson’s ratio and is denoted by 1/m

Poisson’s ratio 1/m = Lateral strain / Linear

strain. The value of 1/m lies between 0.25 to 0.

g. Factor of Safety:

The ratio of ultimate stress to working stress is known as factor of safety.

Factor of safety = Ultimate stress / Working stress.

19

CHAPTER4

INTRODUCTION TO POLYMERS

The term polymer denotes a molecule made up of the repetition of simple unit

monomers. Plastics are produced from the polymers by the combination of latter with

compounding of the plastics.

The importance of the polymers relates to it existence as a material, when

converted into plastics.

A polymer is produced from the monomers characterized by reactive centers, as

a result of polymerization reaction. This polymerization reaction consists of the use of a

catalyst, high temperature & high press. Depending on these conditions one gets a

polymer. In the modern age, the human beings make use of one or stowed other

material made up of plastics in their daily routine.

For one thing, they are complex and giant molecules and are different from

low molecular weight compounds like common salt. A polymer like polyethylene does

not melt sharply at one particular temperature into a clean liquid. Instead, it becomes

increasingly softer sand, ultimately, turns into a very viscous, tacky molten mass.

Further heating of this hot, viscous molten polymer does convert it into various gases but

they are no longer polyethylene.

4.1 Important Polymers

4.1.1 Polyethylene:

This polymer is obtained from ethylene, which is a by product in petroleum

industries. The imperial chemical industries produced polyethylene by polymerization of

ethylene.

There are two types they are,

20

a. Low density

polyethylene.

b. High density

polyethylene.

4.1.2 Polypropylene:

The polymer is obtained from polymerization of propylene using co-ordination

catalyst with the press up to 5 atmospheres & at temperature range (40-110) yield

polypropylene.

4.1.3 PolymethylMethacrylate:

Polymethylmethacrylate is produced by radial polymerization of methyl

methacrylate which is produced from acetone.

4.1.4 Polyvinyl Chloride:

The monomer is prepared from the reaction of acetylene with HC 1,

Polymerization is carried out in suspension or emulsion method. The emulsion

polymerization is carried out at low temperature.

4.1.5 Polyhedral Fluor ethylene:

The monomer Tetrafluoro ethylene is prepared from the dechlorination of

system dichloride tetra fluroethane. The monomer is subjected to emulsion method of

polymerization using peroxide using the indicator.

21

CHAP

TER5

CLASSIFICATION OF POLYMERS

5.1 Thermoplastics and Thermosetting Plastics

Plastics are formed by the combination of polymers with compounding

ingredients. These are classified as

a. Thermoplastics

b. Thermosetting plastics.

Thermoplastics are materials that can be softened by heat and then

formed. Thermosetting plastics are permanently hardened when formed. During

heating followed by cooling of thermoplastics, the bonds soften but the destruction of

materials do not take place on the other hand, in thermosetting plastics, heating affects the

chemical structure and the plastics crumble to powder. Thermoplastics are produced

generally by addition polymerization while thermosetting plastics are produced by

condensation polymerization. Thus the processing of these materials has to be done in

different manners.

The following materials are thermoplastics:

Polyethylene, Polypropylene, Polyvinyl Chloride, Ply Acrylics, Polyamides, Nylon,

Polystyrene

Celluloses, Polyesters.(Saturated).

22

5.2 Components of plastics

The following materials are thermosetting plastics:

Phenol-Formaldehyde Resins, Urea Formaldehyde Resins, Mel Amine-Formaldehyde

Resins, Polyesters (Unsaturated) Epoxy Resins Silicon.

To produce plastics, it is essential to have polymers blended with some external

materials. These external materials are termed “compounding ingredients”. For the

purpose of processing of polymers two plastics these are added to give not only the

required property to plastics but also sturdiness and economical aspects to virgin polymers.

The components of compound of plastics:

• Fillers

• Plasticizers

• Colorants

• Lubricants

• Sterilizer

• Anti Oxidants.

5.2.1 Fillers:

They are added to the polymers to impart special properties and also to reduce the

cost of finished products.

5.2.2 Plasticizers:

They are added to the polymers to increase plastic property and induce more

flexibility to the plastics.

5.2.3 Colorants:

23

They are added to provide pleasing colors to the plastics. These decorative

colors are provided by both organic dye stuff and inorganic salts.

5.2.4Lubricants:

These substances are used to get a good finishing. These are added to most of

the polymers to improve flow within processing machineries and to reduce friction.

5.2.5 Stabilizers:

The polymers may undergo degradation with the formation of conjugated double

bonds along the chain, which result in declaration of the polymer. To avoid this suitable

materials are added, called stabilizers.

5.2.6 Antioxidants:

Polymers are protected against oxidative degradation by incorporating certain

compounds called antioxidants.

24

CHAPTER6

POLYMER PROCESSING

Whether we want to make a toy or fabricate a spacecraft, polymers would

often have some crucial role to play. But how does one convert a polymer into a broad

spectrum of useful shapes and structures? To answer this question, we need to look at

another branch of polymer technology called “polymer processing” which it’s the theme

of this chapter.

In a very broad sense, polymer processing may be defined as an engineering

specialty used to convert polymeric materials into useful end products. Most of the

available techniques now employed in processing technology of polymers are basically

refined versions of those used in ceramic or metal industries. In fact, the need to

understand finer aspects of polymer processing surfaced as conventional materials

were required to be substituted by those with better finish and elegant. They black

ebony or the costly ivory keys in a harmonium or a piano gave way to wooden keys with a

covering of celluloid.

25

26

CHAPTER7

PROCESSING TECHNIQUES

The very fact that polymeric materials are used in many forms such as rods, tubes,

sheets, foams, coatings or adhesives and also as moulded and fabricated articles implies

that there must be a variety of ways in which the compound resins can be processed and

converted in then finished products. A majority of the articles are either moulded or

fabricated, while many others are made by casting liquid pre polymers into a mould and

allowing them to cure of cross-link. Fibers are made by a process known as spinning.

Today, there are many processes and automatic machines for this purpose, the

important ones being calendaring, casting, compression moulding, injection moulding,

extrusion moulding, blow moulding, cold forming, thermoforming, foaming, reinforcing,

melt spinning, dry spinning and wet spinning.

26

CHAPTER8

INJECTION MOULDING PROCESS

8.1 injection moulding

The injection moulding process is best suited for producing articles made of

thermoplastic materials. Here, the equipment cost is relatively high but the main

attraction is the amenability of the injection moulding process to a high production rate.

In injection molding, a definite quantity of molten thermoplastic material is injected

under pressure into a relatively cold mold where it solidifies to the shape of the mould.

The injection moulding machine is shown in the process consists of feeding the

compounded plastic material as granules, pellets or powder through the hopper at

definite time intervals into the hot horizontal cylinder where it gets softened. Pressure is

applied through a hydraulically driven piston to push the molten material through a

cylinder into a mould fitted at the end of the cylinder. The molten plastic material from

the cylinder is then injected through a nozzle material from the cylinder is then injected

through a nozzle into the mould cavity.

The mould used, in its simplest form, is a two-part system. One is a movable part

and the other stationary. The stationary part is fixed to the end of the cylinder while

the movable part can be opened or locked on to the stationary part. The locking device

has to be very skillfully designed in order to withstand high operating pressures.

Furthermore, a proper flow of the molten material to the interior regions of the mold is

achieved by preheating the mould to an appropriate temperature. Usually, this

temperature is slightly lower than the softening temperature of the plastic material

undergoing moulding.

27

After the mould’s filled with the molten material under pressure, then it is either

cooled by cold water circulation or air and then opened so as to eject the molded article.

The whole cycle could be repeated several time either manually of in an automated mode.

28

CHAPT

ER-9

WORKING PRINCIPLE

The Pneumatic injection moulding process is best suited for producing articles

made of thermoplastic materials. Here, the equipment cost is relatively high but the main

attraction is the amenability of the pneumatic injection moulding process to a high

production rate. In pneumatic injection molding, a definite quantity of molten

thermoplastic material is injected under pressure into a relatively cold mold where it

solidifies to the shape of the mould.

The pneumatic injection moulding machine is shown in the process consists of feeding

the compounded plastic material as granules, pellets or powder through the hopper at

definite time intervals into the hot molten plastics. Pressure is applied through a

pneumatically driven piston to push the molten material through a barrel into a mould

fitted at the bellow the nozzle. The molten plastic material from the Hooper is then

injected through a nozzle material. The mould used, in its simplest form, is a two-part

system. One is a movable part and the other stationary. The stationary part is fixed to the

end of the cylinder while the movable part can be opened or locked on to the stationary

part.

By using a mechanical locking device, the mould is proper held in position as the

molten plastic material is injected under a pressure as high as 15×10-2 N/m2. The

locking device has to be very skillfully designed in order to withstand high operating

pressures. Furthermore, a proper flow of the molten material to the interior regions of

the mold is achieved by preheating the mould to an appropriate temperature. Usually,

29

this temperature is slightly lower than the softening temperature of the plastic material

undergoing moulding.

After the mould is filled with the molten material under pressure, then it is cooled

by cold water circulation and then opened so as to eject the molded article. The whole

cycle could be repeated several times by the same procedure. The double acting

pneumatic cylinder is used to inject the molten plastic material into the die.

The flow control valve is used to control the flow of air in to the cylinder. The

direction control valve is used to control the direction of piston movement. These all

valves are already explained in the above chapter.

30

CHAPTER-10

FABRICATION OF MECHINE

The injection moulding is widely used in the modern age. The human beings

make use of one or other material made up of plastics in their routine life. The frame is

designed like a chassis frame with the help of L angle. The frame is finished accurately

& it has provisions to mount the components. There is also a provision to mount the

channels on which the die locking & Die setting system works

The threads are formed on the shafts. The two shafts are mounted on the either

side of the channel. On one side square thread is made & thread is made on another side.

The shafts are tightened by using of hardware. The two shafts hold two plates by drilling

& boring the plate according to the required size. The plates are fixed up and down on

the shafts. There is also two shafts to hold two plates rigidly. The upper plate holds

the Rack & pinion gear mechanism, Rotating wheel, plunger. The bottom plate holds

Hooper, spring, Barrel, nozzle, Heating Coil, Heating Coil Regulator is used to regulate

the temperature of Heating coil.

10.1 Rack And Pinion

Gear:

The rocker & pinion is the main part of the Injection system in injection molding.

The plastic cannot be injected without Rack & Pinion. The Rack & Pinion makes the

operation of Injecting system.

31

10.1.1 Classification of

Gears:

a. Spur gear

b. bevel gear

c. worm and worm wheel

d, helical gear

10.1.2 Construction of

Gears:

The following are the term used in gears.

a. Pitch Circle:

The pitch cycles are the outlines of the imaginary smooth rollers or discs.

b. Pitch Circle Diameter

The pitch circle die is the diameter of an imaginary dix which would produce

the same motion as that produced by the gear, by poor rolling.

c. Addendum Circle:

A circle passing through the tips of the teeth is called addendum circle.

d. Addendum:

The part of the tooth out side the pitch circle is called the addendum.

e. Dedendum Circle:

A circle passing through the roots of the teeth is called dedendum circle.

32

f. Dedendum:

The distance between center to center of two teeth measured along the arc of the

pitch circle is called his circular pitch.

g. Module:

Module is the length of the pitch circle dia per tooth & is given by.

10.1.3 Working:

A gear whose pitch circle dia is infinity is called as rack. The small gear which

meshes with rock is called the pinion. Rock & pinion gear arrangement is used to

convert the linear motion into rotary one & vice versa.

Rotating wheel:

The rotating wheel is arranged with the pinion. The Bearings are attached on

either side of the pinion to give the support to the wheel rod. By rotating of the wheel.

The plunger moves up & down.

Plunger:

The plungers are attached with the rack. By making external threads on rack and internal

threads on plunger. The plunger is used to compress the molten plastic.

10.2 Types Of Springs:

Two types of springs are in common use.

a. Helical spring.

b. Leaf spring.

33

a. Helical spring:

A Helical spring is formed by bending a wire around a mandrel in the form of a

helix. The coil in a helical spring is subjected to torsion and hence its known as Torsion

spring. Helical spring of two types.

• Closely coiled helical spring.

• Open coiled helical spring.

Closely Coiled Helical Spring:

In a closely coiled helical spring the gap between successive turns is so small that

each turn is practically a plan at right angles to the axis of the helix and the wire is subject

to torsion. The bending stress is negligible compared to the tensional stress. This spring

can take up tensile load only.

Open Coiled Helical Spring:

In a open coiled helical spring there is a large gap between the two consecutive

turns. As a result of this the spring can take up compression load also.

10.3 Thread:

When the job is rotated the tool is automatically moved by the lead screw in the

longitudinal direction. The longitudinal feed should be equal to the pitch of the thread to

be cut per revolution of the work. The lead screw has a fixed pitch. So, a ratio between

the rotation of the head stock spindle and the longitudinal feed is found out. The lead

screw is connected by carriage by engaging the half nut lever. So, when the head stock

spindle rotates the lead screw rotates at same speed the pitch of the work will be equal to

the pitch of the lead screw. So far obtaining different pitches on the work, the speed of the

lead screw can be changed by fixing proper change gears between head stock spindle and

leadscrew.

34

CHAPTER11

BILL OF MATERIALS

Sl. No. Name of The Parts Material Quantity

1 Pneumatic cylinder EN-8 1

2 Direction control Valve Aluminum 1

3 Flow Control Valve Aluminum 1

4 Barrel C.I 1

5 L-stand Mild steel 1

6 Vice C.I 1

7 Heating coil Copper 1

8 Hooper C.I 1

9 Connector Polyurethane 5 meter

10 Hose collar Aluminium 4

11 Reducer Aluminium 2

12 Nozzle C.I 1

Table 1.Component

35

CHAPTER12

COST ESTIMATION

12.1Material Cost:

Sl. No. Name Of The Parts Quantity Amount In Rs

1 Pneumatic cylinder 1 2000

2 Direction control Valve 1 550

3 Flow Control Valve 1 600

4 Barrel 1 2000

5 L-stand 1 200

6 Vice 1 300

7 Heating coil 1 1500

8 Hopper 1 300

9 Connector 5 meter 100

10 Nozzle 1 50

Table 2. Cost of Components Total =Rs. 7600

12.2 Total Cost

Total cost = Material Cost Charges

= Rs 7600

Total Cost of Machine = RS 7600

36

CHAPTER13

ADVANTAGES AND APPLICATIONS

13.1 Advantages

• This product is an alternative for plastic cups and plates.

• Cheaper and easily available material is used.

• The pneumatic arm is more efficient in the technical field.

• Quick response is achieved

• Simple in construction.

• Easy to maintain and repair.

• Cost of the unit is less when compared other moulding machine.

• No fire hazard problem due to over loading.

• Comparatively the operation cost is less.

• Continuous operation is possible without stopping.

• It reduces the manual work.

• It reduces the production time.

• Occupies less floor space.

• Less skilled operator is sufficient.

• Different shape of the components can be made according to the die what are

used.

• Adjustable Temperature setting is done with the help of thermo stator.

37

13.2Applications

• The daily using plastic components can be easily made.

• It is very useful in small scale moulding industry

• Textile products can be produced.

• By changing proper die, we can produce any shape of plastic materials with low

cost.

13.3 Disadvantages

• Initial cost is high

• Cylinder stroke length is constant

• Need a separate compressor

38

CHAPTER14

CONCLUSION

Due to it’s low cost, this working model can be successfully inducted in small

scale moulding units and can be used to manufacture small plastic component at an

acceptable cycle rate within an effective cost component.

Existing market machine cost 45000.00

Component cost 22500.00

Total cost 67500.00

Table 3. Cost evaluation of existing machine

Fabricated machine cost 7600.00

Component cost 7600.00

Total cost 7600.00

Table 4. Cost estimation of fabricated machine

39

As exhibited in the above tables, the newly fabricated machine has brought in a

considerable reduction in the cost component when compared to existing cheapest

machine available in the market

Thus we have successfully fabricated a machine which can remove the initial

starting cost hurdle and on basic standards cater to the needs of a small scale industry.

After the completion of fabrication the machine is tested with a wide variety of acrylic

plastic materials over a variable temperature range and plastic ring as the standard product

from the die is manufactured.

This prototype can be subjected to further improvement in product cycle time with

the compromise of the cost based component. A few of the changes which can be brought

about are:

• Introduction of a pneumatic based clamping system instead of the manual

clamping system in order to decrease the cycle time and increase the overall

production rate.

• Manual temperature control system can be replaced with a sensor based

temperature range control system in order to make the process continuous and

improve the cycle time.

40

REFERE

NCES

1. Donald V. Rosado, Marlene G. Rosado. 2000 Concise Encyclopedia of Plastics.

Springer,

2. Douglas M. Bryce. 1996. Plastic Injection Molding: Manufacturing Process

Fundamentals.

SME,

3. International Journal of Engineering, Science and Technology, Minimization of

sink mark defects in injection molding process –Taguchi approach

4. McGraw Hill Book Company, Compressed Air Operations Manual, ISBN 0-07-

147526-5.

5. Oswald, Tim A; Lih-Sheng Turng, Paul J.Gramamn2007. Injection Molding

Handbook

2nd Ed.HanserVerlag.,

6. R.K. Rajput, Heat and Mass Transfer

7. R.S.Khurmi, Machine Design

8. Society for Plastic Engineer s , Journal of Injection Molding Technology, ISSN: 1533-

905X.

9. Stephen Fenichell, 1996,Plastic: The Making of a Synthetic Century, Harper

Business,ISBN

0887307329.