Plastic raw materials according to the scope of application can also be divided into general-purpose plastics, engineering plastics, special plastics.

General-purpose plastics are common: PP, PVC, PE, PS, etc.

Engineering plastics are common: ABS, PC, PMMA, POM, PA6, PA66, PET, PBT, SAN and so on.

Speciality plastics are common: PPS, PEI, etc..

Engineering plastic granules are often obtained by some general plastic modification. Such as changing some of the molecular structure, add other components such as glass fibre and other auxiliary materials.

Engineering plastic is used as industrial parts or shell material of industrial plastics, its strength, impact resistance, heat resistance, hardness and aging resistance are superior plastics.

The Japanese industry defines it as "a high-performance plastic that can be used for structural and mechanical parts, with a heat resistance of over 100°C, and is mainly used in industry".

Its properties include

a. Thermal properties: high glass transition temperature (Tg) and melting point (Tm), high heat distortion temperature (HDT), high long-term operating temperature (UL-746B), wide operating temperature range, and low coefficient of thermal expansion.

b. Mechanical properties: high strength, high mechanical modulus, low latent change, wear resistance, fatigue resistance.

c. Others: chemical resistance, excellent electrical resistance, flame resistance, weather resistance, good dimensional stability.