Around the mid-1920s, Henry Ford was slightly injured by a shard of windshield, which prompted Ford to invent laminated safety glass. Benefiting from the development of the gradually expanding plastics industry, Ford suddenly had an idea to sandwich two pieces of glass together, separated by a layer of PVC plastic to make a kind of sandwich. This technique is still in use. The idea is perfect for windshield requirements because the plastic interlayer prevents the glass from shattering and raining down on occupants in the car like a shower. Another benefit is that this layer of plastic gives the windshield energy-absorbing and shock-absorbing properties that help protect passengers in the event of an accident.