Engineering plastics have excellent comprehensive properties, high rigidity, small creep, high mechanical strength, good heat resistance, good electrical insulation, and can be used in harsh chemicals and physics. It long-term use in the environment, can replace metal as an engineering structural material, occupying an important position in the field of materials. Compared with general-purpose plastics, engineering plastics can achieve higher requirements in terms of mechanical properties, durability, corrosion resistance, heat resistance, etc., and are more convenient to process and can replace metal materials.   Engineering plastics are widely used in electrical and electronic, automotive, construction, office equipment, machinery, aerospace and other industries. With the improvement of materials technology and design technology, the application of engineering plastics instead of metal materials is increasing, and plastics are used to replace steel.   Engineering plastics has become the fastest growing field in the plastics industry in the world. Its development not only supports the national pillar industries and modern high-tech industries, but also promotes the transformation of traditional industries and product structure. Engineering plastics are increasingly used in the automotive field, mainly for interiors such as bumpers, fenders, fuel tanks, instrument panels, body panels, doors, lampshades, fuel pipes, radiators, and engine-related components. In the field of machinery, engineering plastics can be used for mechanical parts such as bearings, gears, screw nuts, seals and other mechanical parts such as housings, covers, handwheels, handles, fasteners and pipe joints. In the field of electronic appliances, engineering plastics can be used for wire and cable coating, printed circuit boards, insulating films and other insulating materials and electrical equipment structural parts.