In addition to maintaining its original protective function, the front and rear bumpers of sedans should also pursue harmony and unity with the body shape, and pursue their own lightweighting. The front and rear bumpers of a sedan are all made of plastic, known as plastic bumpers. The plastic bumper of a typical car is composed of three parts: the outer panel, cushioning material, and crossbeam. The outer panel and buffer material are made of plastic, and the crossbeam is stamped with cold-rolled thin sheets to form U-shaped grooves; The outer panel and cushioning material are attached to the crossbeam.