TYPES OF PLASTICS

Plastics play a vital and key role in our lives. With the increasing utilization of plastic products, new forms of plastic are coming into market day by day. Plastics are divided into two basic types: Thermoplastics and Thermosetting plastics. 

Plastic has become increasingly important in our every day lives. With so many different types of plastics, products meeting a broad range of consumer needs are available. They are organic polymers, which mean they are made of large chain like molecules that contain carbon. These polymers are molded into plastic state. 

Basically, large chainlike molecules are created by hooking together short-chain molecules. The precise process used to create this change, however, results in different types of plastics. Primarily there are two types of plastics. One called thermoplastics and the other as thermosetting plastics. 

Thermoplastic are also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently. Most thermoplastics are high molecular weight polymers whose chains associate through weak Van der Waals forces. 

While thermosetting plastic, also known as a thermoset, is polymer material that irreversibly cures. The cure may be done through heat (generally above 200 °C (392 °F)), through a chemical reaction, or irradiation such as electron beam processing. Scrap created when thermoset plastics are processed, therefore, must be discarded or used as filler in other products. Thermoset plastics are supplied to manufacturers in liquid form or a solid molding powder that has been partially polymerized. They can be formed into their desired shape with or without pressure and heat or chemicals can be used to polymerize them. 

Oddly enough, the line is not clearly drawn between thermoplastics and thermosets. In fact, some types of plastic are made as a combination of the two. 

These two forms of Plastics are further classified into Polyvinyl chloride, Polyethylene, Polypropylene which are thermoplastics and Polystyrene, Polyurethane, Bakelite etc are examples of thermosetting plastics which cannot be remolded.