Polyurethane (PU) is commonly used in the industry of Bullet Resistant Glass (BRG) to adhere the anti-splinter protection layer, made of polycarbonate (PC), on the whole "package" of glass layers.

At Óptima we have decided to use polyurethane (PU) as a sole bonding material in our formulas for every layer (crystal-crystal and crystal-PC) while our competitors are using polyvinyl butyral (PVB) to bond layers of curved crystal. PVB´s less adherence makes delamination easier and its composition causes an instant “Haze” effect. The darker the tone of PVB, the most notorious its lack of transparency.

The following comparison explains better the differences between the characteristics and performance of these two materials when used in armoured glass.