2. Specific strength and specific stiffness: The absolute strength of plastic is not as high as that of metal, but the density of plastic is small, so the specific strength (σb/ρ) and specific stiffness (E/ρ) are quite high. In particular, reinforced plastics made of various high-strength fibrous, flake and powdery metals or non-metal fillers have higher specific strength and specific stiffness than metals.

3. Good chemical stability: Most plastics have good acid, alkali, salt, water and gas properties. Under normal conditions, they do not chemically react with these substances.

4. Electrical insulation, heat insulation and sound insulation performance are good.

5. Good wear resistance and self-lubricating property: plastic has small friction coefficient, good wear resistance, good self-lubricating property, high specific strength and low transmission noise. It can be used in liquid medium, semi-dry or even dry friction. Work effectively under conditions. It can be made into machine parts such as bearings, gears, cams and pulleys, which is very suitable for occasions where the speed is not high and the load is not large.

6. Strong bonding ability.

7. Good molding and coloring performance.