Types of Plastics

There are two types of plastics primarily:

a. Thermosetting and

b. Thermoplastic.

1. Thermosetting Plastics: It requires momentary heated condition and during shaping great pressure. When heated cross linkage is established between the molecules and chemical reaction occurs. Shape can be changed during this stage with pressure. This change is irreversible. The scrap of such type of plastic is not reusable. Bakelite is an instance of such plastic.

2. Thermoplastic: the linkage between the molecules is very loose in this variety. By heating repeatedly they can be softened. This property is helpful for reuse of waste plastic. These plastic require time to cool down and harden. These plastics are to be kept in moulds until cooling takes place fully. Bitumen, cellulose and shellac are the instance of this variety of plastics.