At present, the front and rear bumpers of automobiles in China are generally injection molded with toughened (modified) polypropylene (PP). Polypropylene poly (propylene) plastic has high melting point (up to 167℃), heat resistance and density, and it is the lightest plastic in general use at present, with high internal corrosion resistance.
The strength, rigidity and transparency of its products are good, but the disadvantage is poor low temperature resistance.