Nowadays, plastic has become an inevitable trend to replace expensive metal materials in automobile industry. High strength engineering plastics not only reduce the cost of parts processing, assembly and maintenance, but also make the automobile lighter, energy-saving and environmental protection. According to the data, plastics and their composites are the most important lightweight materials for automobiles. It can not only reduce the quality of parts by about 40%, but also reduce the purchasing cost by about 40%. Therefore, in recent years, the consumption of automobile has increased rapidly and become the “new favorite” of automobile manufacturing.
At present, the most commonly used plastics in automobile plastics are polypropylene (PP), ABS resin, polyvinyl chloride (PVC) and polyethylene (PE). Polyolefin materials constitute the main automotive plastic parts, below are the types of plastic commonly found in automobiles.
PP can be used as a variety of automotive parts, and now in typical passenger cars, PP plastic parts account for more than 60. The main varieties of PP auto parts are: bumper, instrument panel, door trim panel, air conditioner parts, battery shell, cooling fan, steering wheel, among which the first five kinds account for more than half of the total PP consumption of the whole car.
Application: automotive bumpers, chemical tanks, cable insulation, gas cans, carpet fibres.
A series of modified PE alloy materials with good flexibility, weather resistance and coating properties were obtained by grafting and filling toughening modification of high density PE and low density PE resin. PE mainly uses blow molding method to produce fuel tank, vent pipe, deflector and various storage tanks.
In recent years, the amount of PE in the automobile has not increased. It is worth noting that the development trend of automobile lightweight has promoted the plasticization of fuel tank. Plastic fuel tank is officially used in European cars, and its main material is high molecular weight high density polyethylene (HMWHDPE).
Application: car bodies (glass reinforced), electrical insulation.
It has excellent friction and wear resistance, long-term sliding characteristics, forming fluidity, beautiful surface and luster, and is also suitable for insert molding. Polyoxymethylene type three-layer composite material is widely used in automobile chassis lining, such as steering knuckle bushing, various bracket bushing, front and rear leaf spring bushing, brake bushing, etc. it is a three-layer composite material with cold-rolled steel plate as matrix, sintered porous bronze powder as intermediate layer and modified Polyoxymethylene as friction reducing layer on the surface. The special properties of the oil storage pit are determined by its structure: the mechanical strength and rigidity of steel, and the excellent friction and wear resistance characteristics under boundary lubrication conditions. Other applications include door handles, seat belt mechanical components, combination switches and mirrors.
Application: interior and exterior trims, fuel systems, small gears.
Acrylonitrile Butadiene Styrene is a copolymer made by polymerizing styrene and acrylonitrile in the presence of polybutadiene. The styrene provides the copolymer with a shiny, tough exterior. The rubbery butadiene supplies a resilience down to very low temperatures. A wide variety of adjustments can be made to enhance impact resistance, durability and heat resistance. In recent years, the amount of ABS resin used in automobiles has not increased greatly, which is mainly due to the fierce competition between ABS resin and PP resin, and the defects of poor weatherability, discoloration and flammability of ABS itself, so it is used in the main parts of automobile, such as dashboards and wheel covers.
Application: automotive body parts, dashboards, wheel covers.
Polyamide, commonly known as nylon, has high impact strength, friction and wear resistance, heat resistance, chemical resistance, lubricity and dyeability. As a structural part of automobile, the amount of PA is increasing and can be used in harsh environment around the engine.
Application: gears, bushes, cams, bearings, weather proof coatings.