2. What is PLASTIC?
“The plastic is an
organic substance and it
consists of natural or
synthetic binders or
resins with or without
moulding compounds.”

3. “Plastics are compounds of
carbon with other elements such
as hydrogen , nitrogen ,
oxygen.”
“Plastics are polymers.”

4.  Theyprove to be economical as
compare to other
conventional materials.
 They should not be bent too
much to avoid any stresses
in them.
 They are available in various
colours, but it is advisable
to avoid red and black
colours on external expose
surfaces.
 They should provide wood
heat resistance .

5. They should not be affected by
chemicals , salts, acids easily.
Their shape and size should not be
distorted easily.
 Their colours should not be
fedded easily.
 They should durable with good
resistance to cracks and breaks.
 They should possess good strength.

6. 1. THERMO PLASTIC
2. THERMOSETTING PLASTIC

7. “THERMOPLASTIC IS A POLYMER
THAT TURNS INTO A LIQUID
WHEN HEATED AND FREEZES
INTO A VERY GLASSY STATE
WHEN COOLED SUFFICIENTLY.”

8.  They have linear or chain
structure.
 They are produced by
addition polymerisation.
Ex:
Acrylic, PVC, polystyrene,
polyethelene, nylons,etc.

9.  This plastic has cross linked or
network structure.
 It is produced by condensation
polymerisation.
 This plastics need a large prssure and
momentary heat while moulding
which becomes hard on cooling.
remoulding is impossible .

10.  Compare to thermoplastics , this
have high strength.
 Telephone receivers, radio & T.V
cabinets, camera body’s ,
switches, circuit breakers etc
are made from thermosetting
plastic.
Ex :
Bakelite, epoxy, polyesters,
melamine's, etc.

11. It is light in weight.
Specific gravity of plastic is 1.40.
It is easy to cast , mould , blow, saw,
drill. It has good machinability.
It is easy to fix them in any position.
They have high tensile and compressive
strength.
They have low thermal conductivity.
They have low electrical conductivity.
They can absorb shocks.
They are free form corrosion .
They are no attacked by vermin,
insects, etc.
They can be manufactured in wide
range of colours.
It is possible to manufactured plastic
colourless and transparent as well
as non transparent.

12. They are use to make:-
 Furniture like sofa , table ,
chair,etc.
 Optical lenses, spectacles,
frames.
 Handles of tools cases of
machines , covers.
 Electrical and heat insulators ,
electrical appliances and
accessories.
 Cooking wears, table wears.
 Water proof doors, bags.
 Sanitary fittings like taps ,
pipes, valves etc.

14. THE END