Glazing

Soda-lime-silica glazing is the most well-known application and is attributed to economical reasons. Glazing can be produced as flat glass with excellent surface quality, using the float process developed by Pilkington in the1960s. This good surface quality encompasses improved optical and mechanical performance. For safety reasons, in particular in buildings and transportation, glazing are either tempered (strengthened) or laminated, that is, formed by two substrates bonded by a polyvinyl butyral (PVB).Tempered glazing offer more mechanical resistance and eventually break into small harmless pieces. For very high strength levels required for airplanes and trains, chemically tempered glazings are preferred. Laminated glazing are preferred for roofs since, once breakage happens, roofs remain in one single piece thanks to the PVB bond. Optical transparency may be tailored by sanding, etching or rolling the glass. This is very popular in interior architecture. Insulated glasses allow for reducing heat transfer which occurs by radiation, conduction and convection. Through the use of insulated glass units with a low- conductivity gas fill between two or three panes of glass, conductive and convective heat loss can be significantly reduced. Radioactive heat loss requires tinted or coated glazing. In fact, while visual transparency is in most cases required, tailored properties have been developed in infrared (IR) and ultraviolet (UV) domains to reduce heat transfer. For vehicles, glazings with complex shapes are now being fabricated. In fact, glazing is an integral part of the design of new cars. Moreover, glass roofs have become more and more attractive. With increasing glazing surface area, anti solar coatings are required. Such coatings are detected on the wind- screen since they reflect blue (Renault vehicles) or pink (Pontiac vehicles) colours. As mentioned for building applications, IR insulation is now necessary to prevent extreme temperatures in vehicles during summer and at the same time to reduce gas consumption resulting from air-conditioning that equips most vehicles having large glazing areas.