The unique low specific gravity, high tensile strength, wear resistance, good self-lubrication, excellent impact toughness, with both rigid and flexible performance and win people's attention, coupled with its simple processing, high efficiency, light specific gravity (only 1/7 of the metal), can be processed into a variety of products to replace metal, widely used in the automobile and transportation industry. Typical products are pump impeller, fan blade, valve seat, bushings, bearings, various instrument panels, automotive electrical instruments, hot and cold air regulating valves and other parts, about each car consumption of nylon products up to 3.6 ~ 4 kg. The consumption proportion of polyamide in the automobile industry is the largest, followed by electronic and electrical.