Laminated glass is made of two or more layers of glass with one or more “interlayer’s” of polymeric material bonded between the glass layers. Laminated glass is produced using one of two methods:
- Poly Vinyl Butyral (PVB) laminated glass is produced using heat and pressure to sandwich a thin layer of PVB between layers of glass. On occasion, other polymers such as Ethyl Vinyl Acetate (EVA) or Polyurethane (PU) are used. This is the most common method.
- For special applications, Cast in Place (CIP) laminated glass is made by pouring a resin into the space between two sheets of glass that are held parallel and very close to each other.
Laminated glass offers many advantages. Safety and security are the best-known of these — rather than shattering on impact, laminated glass is held together by the interlayer, reducing the safety hazard associated with shattered glass fragments, as well as, to some degree, the security risks associated with easy penetration. But the interlayer also provides a way to apply several other technologies and benefits, such as coloring, sound dampening, resistance to fire, ultraviolet filtering, and other technologies that can be embedded in or with the interlayer.
Laminated glass is used extensively in building and housing products and in the automotive and transport industries.
- Safety:Ordinary window glass is brittle, breaking into long sharp pieces which can cause serious injuries. The principal feature of laminated safety glass is that the interlayer absorbs the energy impact and hence resists penetration. Although the glass may break, the glass fragments remain firmly bonded to the interlayer, minimizing the risk of injuries.2. Security: Burglars often try to break windows to get inside the house or a building and here the laminated glass plays an important role in resisting their intrusion. Even if the glass breaks the interlayer continues to safeguard the building until the glass is replaced
- Sound Reduction:Noise gains easiest entry to homes and buildings through windows and doors. Laminated glass proves an excellent barrier to noise; it has better Sound Transmission Loss as compared to glass of similar thickness in the frequency of 125 Hz to 4000 Hz. Also it eliminates the coincidence dip that is associated with the monolithic glass because of the viscoelastic property of the interlayer material.4. Solar Energy Control: While natural light is important for us too much sunlight can also mean too much heat gain inside the building. Laminated glass when used in combination with reflective glass, tinted glass or low e glass provides excellent reduction in the Solar Gains as well as reduction of sound transmission through the window.
5. UV Control: The major cause of deterioration and fading of furnishings and pictures is the chemical reaction caused by short-wavelength UV radiation. UV absorbing additives in the interlayer in laminated glass can screen out almost all these damaging rays.
6. Protection from weather and natural disasters: If broken, laminated glass remains in its frame, preventing interior damage while reducing flying glass protects people both indoors and outdoors. Areas subjected to heavy winds and rain such as hurricanes or cyclones, buildings often need extra protection. Flying debris carried by these winds can shatter the glass and injure people. Laminated glass can be designed to remain intact and in its frame. Buildings that are situated in areas subjected to heavy winds and rains such as hurricane and cyclones often need extra protection.
7. Durability: Laminated glass is durable; it maintains its color and its strength for a very long time.
8. Low visual distortion: Laminated Glass is usually glazed in an annealed form, avoiding the distortion caused by roller waves in the tempered and heat strengthened glass. So the facades having laminated glass have sharp reflected images and fewer distortion.