The document discusses various topics related to plastics manufacturing including types of plastics, polymerization processes, properties of thermoplastics and thermosets, and common shaping processes. It describes how thermoplastics can be softened by heat and reshaped, while thermosets undergo a chemical change and maintain their shape after heating. Common industrial manufacturing techniques for plastics are also summarized, such as injection molding, blow molding, rotational molding, extrusion, and thermoforming.

1. MANUFACTURING OF PLASTIC COMPONENTS
Types of plastics - Characteristics of the forming and shaping processes –
Moulding of Thermoplastics – Working principles and typical applications
of - Injection moulding – Plunger and screw machines – Compression
moulding, Transfer moulding – Typical industrial applications –
Introduction to Blow moulding – Rotational moulding – Film blowing –
Extrusion - Thermoforming, - Bonding of Thermoplastics.

2. ORGANIC MATERIALS
 Natural – Wood, Coal, Petroleum &
Natural Rubber
 Synthetic – Plastics, Synthetic rubber,
Ceramics & Glass
 Organic material - Polymers

3. Polymers
 Poly means ‘Many’ & ‘Mers’ means ‘Parts’
 Polymer built of several repeating
units(Monomer)
 Monomer – small molecules
 Polymer is made up of thousands of
monomers jointed together to form large
molecule.
 Plastics – Organic polymer
 The Main raw material for making plastic is
resin.
 Resin – acrylic resin, polyethylene resin

4. Polymerization process
 A Polymer is made up of linking thousands
of monomer and thus obtaining large
molecule is called Polymerization process
 Additives – Plasticizers (liquid form) –
Water, Organic solvents & resins
 Catalyst – Promote faster & complete
Polymerization
 Dyes – Impart desired colour
 Initiators – Initiate the reaction (H2O2)
Hydrogen peroxide

5.  Addition polymerization:
 Similar monomers of large numbers are added
chemically one by one
 These monomers form a long chain molecule.
 Polyethylene is produced by addition polymerization,
 Condensation polymerization :
 Two or more unlike monomers are linked and there is a
repetitive elimination of smaller molecules to form a by-
product. During this process, by-product such as water or
ammonic is formed.

6. Plastics
 Can be moulded into required shape
with the help of pressure or heat or
both heat and pressure
 Resin – liquid form of plastics, also raw
material for making plastics
 Types of resin: acrylic resin,
Polyethylene resin & amino resin –
Produced by polymerization process
 Catalysts, Binders & Lubricants added
with resin to form plastics

7.  Modifiers – To improve the mechanical
properties of plastics
 Lubricants – To reduce friction during processing ,
Avoid sticking to mould walls(Oils, Soaps and
waxes)
 Solvents – Dissolve fillers or Plasticizers & Allow
the processing in fluid state(Alcohol)
 Fillers – Mica, Cloth fiber
 Elastomers – To enhance the elastic properties

8. Properties of Plastics
 Elongation
 Heat resistance
 High rigidity
 Surface hardness
 High viscosity
 Density
 Chemical resistance

9. Thermosetting Plastics
 Thermosetting - Plastics which are hardened by
heat effecting non reversible chemical change .
 Plastics do not soften on reheating and cannot be
reworked.
 Molecules are formed by condensation
polymerization process.
 All the molecules have three dimensional
network and very strong binding force between
molecules
 Bakelite, Polyester resin, Epoxy resin(Araldite),
Silicones, Urea formaldehyde(Amino resin) &
Alkyds

10.  Phenol formal dehyde: Reaction of phenol with
formaldehyde.
 Produced dark colour and it has high strength, stability
and rigidity.
 Uses: plugs, knobs, pulleys, bottle caps, tooling and
forming die.
 Polyster resin: Low moisture, good electrical resistance
and variety of colours.
 It is used in paper mat, TV parts and car bodies.
 Main drawback is polyster is high cost.
 Epoxy resin: most popular variety of epoxy resins is
Araldite. Good chemical and electrical resistance.
 Mostly available in the form of liquid.
 Good resistance to wear and impact.

11. Thermo Plastics
 Have separate long and large size molecule arranged
side by side
 When thermoplastics are heated it becomes very soft
and rehardens on cooling
 During heating the linear bonding links between
molecules are breakup and separated. Relinking takes
place on cooling and retains their hardness.
 Cellulose nitrate – pen bodies, Table tennis balls, Frames
 Ethyl cellulose – Jigs, Fixtures, hose nozzles
 Cellulose acetate - Radio cabinets, steering wheels,
Insulating tapes

12. Synthetic resins
 Polyethylene – Fabrics, tray, pipes, tubing chemical
containers & corrosion resistant coatings
 Polystyrene - Battery boxes, radio parts, toys
 Vinyles(PVC) – Tarpaulin, Water roofing, raincoats, tubes
 Polytetra fluroethylene (Teflon)- Gaskets, Greaseless
bearing, Electrical insulators, Chemical containers
 Polyamide(Nylon) – Gears, wire insulation, combs,
Bearings and couplings

13. S.
No
Thermoplastics Thermosetting plastics
1 Softened by heating Cannot be softened by
heating
2 Structure is made of linear
chain molecule
Structure is made of cross-
linked molecule
3 Produced by addition
polymerization process
Produced by condensation
polymerization process
4 Can be reproduced by
heating and cooling
Cannot be reproduced
5 When the temp increases
the plasticity also
increases
Plasticity is stable at high
temperature
6 Softer and less strong Harder and strong
7 Scrap can be reused Scrap can not be reused

14. INJECTION MOULDING
1) RAM OR PLUNGER TYPE INJECTION MOULDING

15. THERMOPLASTICS - INJECTION MOULDING
2) SCREW TYPE INJECTION MOULDING

16. THERMOPLASTICS – INDUSTRIAL APPLICATION
2) BLOW MOULDING

17. THERMOPLASTICS – INDUSTRIAL APPLICATION
3) ROTATIONAL MOULDING

18. THERMOPLASTICS – INDUSTRIAL APPLICATION
4) FILM BLOWING

19. THERMOPLASTICS – INDUSTRIAL APPLICATION
5) SHEET MAKING

20. THERMOPLASTICS – INDUSTRIAL APPLICATION
6) EXTRUSION PROCESS

21. THERMOPLASTICS – INDUSTRIAL APPLICATION
7) VACUUM FORMING PROCESS ( THERMO FORMING)

22. THERMOSETS
1) COMPRESSION MOULDING

23. THERMOSETS
2) TRANSFER MOULDING

24. BONDING OF THERMOPLASTICS