What are the advantages of engineering plastics over traditional metal materials?

With the development of modern materials science, engineering plastics as a new material is increasingly used in the manufacture of mechanical parts. Engineering plastic parts are increasingly widely used, from hand tools to industrial machinery, from medical equipment to semiconductor equipment, some of the advantages of plastic parts even beyond the metal parts. Engineering plastics compared to metal materials with light weight, high strength, low coefficient of friction, transparent, self-lubricating, processing efficiency is high and other excellent performance, can withstand high mechanical stress and more demanding conditions of use. For example, polycarbonate can be used to make the skylight of supersonic aircraft, which is a high impact resistance transparent material, and can withstand a temperature of 145 ℃; polyformaldehyde is often used to make bearings, bushings, and precision pinion, etc., which has the characteristics of high rigidity, high hardness, self-lubrication, low coefficient of friction, and good fatigue resistance.