Laminated glass is produced these days using one of two different methods: either the PVB interlayer, or so-called "cast in place" resins. However, both types of interlayers play a crucial part in the final properties of the laminated glass unit.
Polyvinyl butyral (PVB) is a special tough and resilient material which is sandwiched between two layers of glass and then permanently bonded using high temperatures and pressure.
Generally, the PVB interlayer is 0.38 mm thick, although for auto or extra strength interlayers 0.76 mm thicknesses are used. In the ‘cast in place’ process liquid resins are poured or cast between two sheets of glass and then polymerised with U.V. radiation or by catalysis.
The major benefits of the "cast in place" process is that it can produce a wide variety of designs and thicknesses while maintaining the benefits of laminated glass. Therefore, the "cast in place" process is used mostly for non-standard dimensions of laminated glass.
These resin systems can be also used for laminating glass to plastic, or plastic to plastic as PVB is limited only to glass to glass laminating.
Liquid resins are mostly used in internal areas, where safety performance would normally be of secondary importance. Information about both types of processes is available on the selected links.