2. PLASTICS
โข It is a organic polymer
โข It can be moulded in to any desired shape with
the help of heat.
โข Properties such as:
โ Low cost
โ Color range
โ Water resistance
โ Low electrical and thermal conductivity.
3. SOURCES OF RAW MATERIALS OF
PLASTICS
โข Animals and vegetables by products.
โข Coal by products (Distillation of coal)
โข Petroleum by products ( refining of crude oil)
4. CLASSIFICATION OF PLASTICS
โข THERMO PLASTICS
โข THERMO SETS
โ THERMO PLASTICS:
โข Plasticity increases with increase in temperature
โข Its liquid when heated hardened when cooled
โข Its are soft and ductile
โ THERMOSETS:
โข Permanent hard , not soften when heated
โข It cannot be remoulded
โข Its harder, stronger, more resistance to heat.
5. COMMODITY AND ENGINEERING
PLASTICS
โข Commodity plastics are used for a commodity
purpose( home).
โข Engineering plastics are used for the
engineering purpose.
โข Both plastics are having
โ Thermo plastics
โ Thermo sets plastics.