What is the purpose of energy-absorbing foam in a vehicle bumper?

The purpose of energy-absorbing foam in a vehicle bumper is to reduce the severity of injuries to pedestrians and vehicle occupants in low-speed collisions. The foam, typically made of a deformable material like expanded polypropylene (EPP) or polyurethane, is positioned behind the bumper fascia (the outer plastic cover). In a low-speed impact, the foam compresses, absorbing some of the energy from the collision. This reduces the force transmitted to the pedestrian or the vehicle's occupants, minimizing the risk of injuries such as leg fractures, whiplash, and other soft tissue damage. The energy-absorbing foam also helps to protect the vehicle's structural components from damage in minor collisions, reducing repair costs. The foam is designed to crush and deform in a controlled manner to maximize energy absorption.