The Structure and Material of a Car Bumper

The front and rear ends of the car are fitted with bumpers. They not only serve a decorative function but also, more importantly, absorb and soften the impact of external forces. In short, the car bumper is a safety device that protects the body and the occupants.

The structure of a car bumper

The outer panel and the cushioning material are made of plastic. The crossbar is made of a cold-rolled sheet with a thickness of about 1.5 mm. And it is stamped into a U-shaped groove. The outer plate and the cushioning material are attached to the crossbar. And it is screwed to the longitudinal beam of the frame and can be removed at any time. The plastic used in this type of bumper is largely made of polyester and polypropylene and is made by injection molding.

Materials of car bumpers

• At present, domestic front and rear bumpers are generally made of toughened (modified) polypropylene (PP) as the raw material for injection molding. Polypropylene (PP) plastic (commonly known as PP material) has a high melting point (up to 167 degrees Celsius), is heat resistant, and has a density (0.90g/cm3), making it the lightest of the general-purpose plastics available.

• It has a high corrosion resistance (sheet strength of 30 MPa). The strength, stiffness, and transparency of its products are relatively good. The disadvantage is the poor low temperature resistance (by the impact-resistant polypropylene copolymer, styrene elastomer, and polyolefin rubber 3 compositions of the blend of modified materials.

• With high stiffness, impact resistance, scratch resistance, and applicability. Injection molded bumper load-bearing, subject to 8 km/h collision without breaking, and with recovery elasticity. It has similar properties to polyurethane and costs 10% to 20% less.