A windscreen or the vehicle glass in the front of your automobile or truck is not composed of a single sheet of manufactured glass. It's really two layers of glass that are divided by a complete layer of polyvinyl butyrate. This layer of PVB generally glues as well as seals the two items of glass with each other. This offers a number of purposes, though the most essential is to keep the honesty of the windshield. In case of damage, the windshield is less most likely to ruin.