Ballistic Glass

Ballistic glass is not a single pane but a lay-up. Hard tempered glass plies on the attack side meet the bullet, deform it and use up part of its energy as they fracture; interlayers bond the plies and limit crack growth. A polycarbonate layer on the protected side flexes to absorb the remaining energy and helps keep glass fragments from flying inward. The result is armor that stays transparent. Because each layer has its own role, ballistic glass must be installed the right way round, with its attack face outward.

The protection class is expressed from BR1 to BR7 under EN 1063; the higher the class, the more severe the test threat, and the thicker and heavier the glass. A bank counter must keep eye contact and voice communication with customers, a VIP vehicle needs glass that fits its door and body structure, and a control tower needs a wide, uninterrupted view. In every application, class, size and frame are therefore designed together: glass mounted in a frame of a lower level becomes the weak link in the chain.