At first glance, bulletproof glass looks identical to an ordinary piece of glass, but that’s where the similarities end. Ordinary glass shatters when struck by a single bullet. Bulletproof glass, more accurately known asbullet resistant glass, is designed to withstand one or several rounds of bullets depending on the thickness of the glass and the weapon being fired at it. So, what gives this bullet-resistant glass the ability to stop bullets?
Different ballistic glass manufacturers make different variations of bullet-resistant glass. It’s basically made by layering a polycarbonate material between pieces of ordinary glass in a process called lamination. This process creates a glass-like material that is thicker than normal glass. Polycarbonate is a tough transparent plastic — often known by the brand name Lexan, Tuffak or Cyrolon. Bulletproof glass is between 7 millimeters and 75 millimeters in thickness. A bullet fired at a sheet of bullet-resistant glass will pierce the outside layer of the glass, but the layered polycarbonate-glass material is able to absorb the bullet’s energy and stop it before it exits the final layer.
Although the layers of glass within bulletproof glass can break, the polycarbonate layers which are bonded to the glass prevent them from shattering and flying apart, and so the whole structure remains intact, unlike normal glass where the pieces fly everywhere.