Glass is generally obtained by melting a mix made up of quartz sand, limestone, sodium (or potassium) carbonate and auxiliary materials in special furnaces. The physical properties of the glass are determined by their composition and the heat treatment it is subjected to.
The symbolic name of anti-ex glass refers to safety glass.
Safety glass is used in the structure of machinery (manholes), in glass walls, double glazing or laminated glass etc. – especially for applications that require the following:
Resistance to mechanical shock (glass doors, glass sheets fastened to punctiform supports such as glass railings etc.).
Resistance to heat stress (glass exposed to intense sunlight or mounted near sources of heat such as coloured glass splashbacks etc.)
Protection against the risk of shattering, as well as reducing risk of injury.
Venting blasts from explosions (in this case, the glass sheet is scored beforehand to allow breaking in the direction desired).
Glass hardening is the thermal process of heating it up to 700-740 C˚ and then quickly cooling it to room temperature – through which the material becomes 5 times as hard without losing any of its elasticity. One important feature of safety glass is its behaviour when it shatters; compared to normal glass, safety glass breaks into tiny fragments and not large and jagged pieces.