The main plastic material of the car (2)
Second, engineering plastics
Engineering plastics are widely used in the automotive field due to their good comprehensive mechanical properties. In this paper, polyamide (PA), polymethacrylate (PMMA), polyoxymethylene (POM), polyamide (PU) are mainly introduced. ), polycarbonate (PC).
Polyamide, commonly known as nylon, is widely used in industrial applications. PA6, PA66 and PA610 are commonly used. The water absorption rate is 100%, and it can absorb 8% when it is saturated with moisture absorption. The suitable wall thickness is 2 to 3.5 mm.
PA is mainly used in the automotive field to manufacture hoses (brake hoses, fuel pipes), combustion oil filters, air filters, oil filters, water pump housings, water pump impellers, fans, brake fluid tanks, power steering fluid tanks. , white leaf window, headlight shell, seat belt.
Polymethacrylate, commonly known as plexiglass, is resistant to outdoor aging and has excellent transparency. Suitable plastic products: transparent structural parts with certain strength requirements.
PMMA is widely used in automotive lighting signs, door glass and lamp glass covers due to its good light transmission properties.
POM uses and manufactures instrument panel glove box accessories, various valves (drain valves, air conditioner valves, etc.), various impellers (water pump impellers, heater blades, oil pump wheels, etc.), various electrical switches and electrical instruments. Small gears, various handles and door pins.
Polycarbonate has outstanding impact toughness and creep resistance, good heat resistance and good cold resistance. The addition of PC to glass fiber can improve its shrinkage, mechanical strength and temperature resistance. The long-term use of steel at 100 °C will increase, and the internal stress can be improved by annealing.
Introduction to the main synthetic PC-ABS:
PC-ABS is a blend of PC and ABS, which is usually supplied in pellet form after blending. If only two materials are simply mixed, direct injection molding, the effect is very poor, there will be stratification; PC has the advantage of being rigid and tough, the disadvantage is stress cracking, high viscosity; ABS has the advantage of good fluidity, but the surface The hardness is low; the blended material PC-ABS retains the advantages of both; PC-ABS has high surface hardness, high rigidity and toughness, and high resistance to stress cracking; its mechanical properties Between the two.
In the automotive field, PCs are mainly used in the manufacture of lampshades, left and right wheel cover guards, instrument baffle bodies (PC+ABS), left and right windshield covers, intermediate windshield covers (PC+ABS), and rear bumper cushions.
Polyurethane is generally classified into a rigid polyurethane and a flexible polyurethane depending on the polymerization product.
Polyurethane foam is widely used in automotive interiors and vibration absorbing parts, such as coating materials, polyurethane rigid plastic sheets, polyurethane elastomers, seat soft foam materials, decorative parts, sofa leather, roof ornaments; It is a variety of soft and rigid polyurethane foam materials, it has vibration isolation, sound insulation, noise reduction, thermal insulation; PU can also be made into automotive polyurethane coatings, adhesives, sealants and so on. The PU on the car represents the instrument panel, rear view mirror, bumper, seat cushion, headrest, steering wheel, instrument panel anti-vibration pad, pillar trim, front roof lining, window frame, ceiling and side top Frame decoration, door lining, sun visor, rear top frame decoration, etc.