Laminated is a type of safety glass which holds together when shattered. In the event of breaking, the glass is held in place by an interlayer, such as CIP or EVA (explained below), between the layers of glass. The interlayer keeps the layers of glass bonded even when broken, and its high strength prevents the glass from breaking up into large sharp pieces, which produces a characteristic “spider web” cracking pattern when the impact is not enough to completely pierce the glass. It is often used in applications such as building facades, shop front windows, security screens, walk on floors, overhead canopies, domes etc.
i) Cast in place (CIP)
The edges of the glasses are taped using translucent double-sided adhesive tape. The tape retains the liquid and determines the thickness of the resin interlayer. The liquid resin is pumped, into the envelope, where it spreads evenly – even between irregular surfaces. All the air is removed out and corners and drilled holes are sealed with a translucent silicone to prevent the resin from escaping. The glass is put beneath UV lamps for approximately 20 minutes. CIP is ideal for curved and domed glass, where exceptional optical quality is required.
ii) Ethylene vinyl acetate (EVA)
A sheet film of EVA (to a maximum width of 2.4 meters) is placed between two sheets of glass, a vacuum is applied to force the glasses together and then it is heated to soften the film and make it adhere to the glass.
EVA has a high tensile strength, excellent transparency, outstanding cohesion properties, good resilience to temperature changes, humidity, durability and long-term reliability. It is ideal for areas prone to moisture such as shower screens and wet rooms. It is often used for increased safety, security and sound insulation for various indoor and outdoor applications.
Laminated safety glass is considerably more impact resistant than conventional glass. Tests have shown it is some 30 times more intruder-resistant than conventional toughened glass. It is strong enough to withstand a vigorous attack from a heavy or sharp weapon. It can resist an aggressive attack for 20 to 30 seconds compared to toughened glass which would resist a similar attack for only one or two seconds.
Tower Glass can also produce multiple lites laminated together for use in high security applications such as banks, jewellery shops, computer rooms and other areas where a high impact or even bullet resistant glass is required. Any combination of glasses from our extensive range including toughened can be used to produce laminated glass.