The ability of multi-functional plastics to be integrated in car body parts

Plastic Surface Quality Requirements Regardless of which coating process is used, the surface quality of the bodywork must meet Class A requirements. Therefore, the plastic must have good processing fluidity. In addition, in order to ensure the smallest possible gap size between components under extreme temperature conditions, the coefficient of thermal expansion of the body plastic part must be small. If the body plastic part is used as the skin of the metal substrate, the appearance quality can be guaranteed only if the thermal expansion coefficients of the substrate and the surface layer are close to each other. In general, thermoplastics have a much larger thermal expansion coefficient than steel, and their thermal expansion coefficient is generally reduced by the addition of fillers. However, the addition of fillers will always reduce the surface quality. Fiber-reinforced thermosetting plastics mostly meet the requirements of body structural parts in terms of strength and rigidity, but their surface quality is often difficult to meet Class A requirements. In addition, the fiber-reinforced plastic paint is also very difficult.

Another option to solve this problem is to use an injection-composite process that combines highly filled plastics with already colored high surface quality films/sheets by injection. The composite components produced no longer need to be painted and can meet Class A surface quality requirements. BASF co-operated with other companies to study the production of long-fiber-reinforced ABS, co-extruded poly(methyl methacrylate) and ASA co-extruded film for the production of the car's tailgate (baggage compartment lid); GE produced a polycarbonate Extruded sheet (Model: Sollx), already used in the production of body parts for mini-vehicles 2 Status of application of plastics in car bodies 2.1 Plastics for body parts Light weight, good processability, high design freedom, multi-function The ability of plastics to be integrated in the application of car body parts is the most interesting aspect of plastic as a body material. Especially in today's era of personalization, the style of the car has a great influence on the customer's desire to buy. The plastics currently used as bodywork are mainly sheet-type molding compounds (SMC), reinforced-resin-injection polyurethanes (PUR-RRIM) and glass-reinforced thermoplastics. The use of glass fiber reinforcement in all three types is mainly to meet the rigid requirements of the body.