Plastic is a kind of material with polymer synthetic resin as the main component, which has plasticity and fluidity under certain temperature and pressure, can be molded into a certain shape, and can keep the shape unchanged under certain conditions. General plastics: large output, wide use, good formability and low price; Special plastics: good mechanical properties, high and low temperature resistance, good dimensional stability; Engineering plastics: outstanding high temperature resistance, self-lubricating and other special functions.

1、 Plastic definition

Plastic is a kind of material with polymer synthetic resin as the main component, which has plasticity and fluidity under certain temperature and pressure, can be molded into a certain shape, and can keep the shape unchanged under certain conditions.

Plastic composition: synthetic resin+auxiliary materials

Auxiliary materials: plasticizer, filler, stabilizer, lubricant, colorant, foaming agent, reinforcement, etc.

Auxiliary material function: improve the use and processing properties of materials.

Synthetic resin: generally refers to a class of high molecular weight polymers formed by polymerization or condensation of monomers.

2、 Classification of plastics

(1) Classification according to use characteristics: general plastics, special plastics, engineering plastics

General plastics: large output, wide use, good formability and low price;

Special plastics: good mechanical properties, high and low temperature resistance, good dimensional stability

Engineering plastics: outstanding high temperature resistance, self-lubricating and other special functions

(2) Classification according to physical and chemical properties: thermosetting plastics, thermoplastics

Thermosetting plastics: hardening after heating, hardening and cooling

Thermoplastic: It can be softened and flow when heated, hardened when cooled, and softened when reheated

(3) Classification according to processing method: molding, blistering, compression molding, extrusion molding, injection molding, blow molding, calendering, foaming molding