Tempered glass is also known as toughened glass. The cut-to-size glass sheets are fed into the furnace until it reaches approximately 650°C. Then the glass moves into the quench where it is rapidly cooled by blasting both sides with air. The rapid quenching induces compressive stresses to the glass surface while the centre remains in tension. Even though the physical characteristics remain unchanged, the additional stresses created within the glass increases its strength by 4 – 5 times that of annealed glass of equal thickness. In addition to clear glass, it also offer various tints, Low-E glass, hard-coat reflective glass and some temperable soft-coat reflective glass. In the event of breakage, the panel will fracture into relatively small harmless particles.
Tempered glass has greater resistance to thermal stress when compared to annealed glass (temperatures 70°C to 290°C). Thanks to its mechanical strength, it is ideal for creating a frameless or ‘transparent structure’ concept in all glass assemblies, shop front, curtain wall. It is recommended for doors, side panels, glass balustrades, shower screens, glass walled squash courts. It is also used in automotive and furniture applications.