As the name suggests, laminated glass comprises layers of glass in a sandwich type arrangement. In this case, the normal configuration is a layer of flexible polymeric material sandwiched between two layers of glass. Laminated glass is produced using one of two methods:
• Poly Vinyl Butyral (PVB) laminated glass
• Cast in Place (CIP) laminate
PVB laminated glass is produced using a heat and pressure process, sandwiching a flexible interlayer between layers of glass. Generally, the interlayer has a thickness of 0.38mm, except for applications such as automotive windscreens, which use a 0.76mm thick interlayer.
CIP laminated glass is manufactured by pouring resin into the cavity between two adjacent panes of glass. Interlayer thicknesses of 1.0 to 1.5mm are common for CIP laminated glasses.
Laminated glass has the advantage over standard glass in that it will not shatter as the polymeric interlayer is not subject to brittle failure as is the glass. Furthermore, the interlayer provides a barrier against penetration. Tinted interlayer materials can be used to help minimise heat transmission, while the polymeric material also acts as a sound deadening layer, damping sound transmission in a manner equivalent to glass twice as thick.