Tempered Glasses

This type of glass, in other names as reinforced glass safety glass, is more resistant to cracking compared to regular type of glass. Regular glass can cause injuries falling into sharp pieces after cracking. Tempered glasses, however, break apart into small blunt pieces. Therefore, injury risk is minimized. Tempered glasses are 5 times more resistant than regular glasses that has the same thickness. Its heat resistance is also higher than those of regular glasses.

Tempering is, heating the glasses with 600°C - 650°C with special heating systems then exposing them to air at once, thus cooling them. With the heat decreasing, the surface of the glass hardens. With the cooling of the outer side then the inner sides, there is pressure stress on the glass surface, tensile stress in the inner side of the glass.  

After the glasses are tempered, no cutting, reboring, metal removing can be done on the glass surface. Heat treatments that are done, do not change the volume, color, clarity chemical structure of the glass.

While the glass that is tempered can resist 300°C thermal shock, the glass that is not tempered can crack when exposed to 40°C thermal shock.

‘’Dropping a marble from the height experiment’’ is applied on mechanically testing of the tempered glasses. While a 6 mm tempered glass cracks with the effect of 500 gram steel marble dropped from 5 meters high, a regular glass which is not tempered, cracks with the same amount of marbles but only dropped from 30 cm high in the same experiment. 

Except from full tempered glasses, partially tempered glasses are also resistant to external force heat stress. Partially tempering is also done in the same heaters in the same heat as the fully tempering is done. The only difference in this process is that cooling is done relatively more slowly. Pre stress on the surface the cracking risk of glasses  that are cooled more slowly is lower. Since partially tempered glasses can break into bigger pieces during cracking, they can stay in the cutting space their cracking risk is lower, full tempered glasses are preferred in curtain walls.

     They are used in the glasses used for exterior walls of the buildings, in furnace doors, vehicle glasses, shower bath glasses, table glasses, glass railings, glass furniture, plates cooking pans.