3. PLASTIC
• Any non-metallic material that can be moulded
to desired shape.
• Raw materials of plastic:
The basic raw materials for plastic are the following natural
substance.
(1)Coal (2)Petrolium
(3)Limestone (4)Salt
(5)Sulphur (6)Air
(7)Water (8)Cellulose.
4. CONSTITUENTS OF PLASTIC
• Binder: Pollymeric compound use as binder.
• Fillers: The material added to the plastic to
improve their mechanical properties and then
ecnomical are called fillers.
• Plasticizers:Plasticizers are added to make them
soft and to improve their toughness to make then
flexibal like vegitable oil etc.
• Colouring matter:Chromium oxide and altrmrine
are added for colour in plastic.
5. CLASSIFICATION OF
PLASTIC
• Thermoplastic:Those plastic which are soften on
the application of heat with or without pressure
and require cooling to be set a shape.
• Uses:Toys,combs,toilet,goods, photographic
films,insulting tapes,electric insulation.
6. • Thermosetting:Those plastic which require heat
and pressure to mould them into a shape is called
Thermosetting.
• Uses:Telephone receivers,electric
plugs,radio and T.V cabinats, camera,automobiles
parts etc.
7. PROPERTIES OF PLASTIC
• Durability:Corrision resistance allowing to survive
outside In any wheather.
>Cost Effectiveness: Many plastic maerial are
very economical.
>Recycling:Unlike metals some plastic can be
recycle with out lossing any chemical properties so
we can use over and over again.
>Safety:Plastic material are much lighter then
metal.
