Glass is heated to a temperature below softening temperature at a certain heating rate in a heating furnace, and then the glass is rapidly fed into a cooling device, quenched by low temperature and high speed air flow. The outer layer of the glass shrinks and hardens first. Because the thermal conductivity of the glass is small, the interior is still in a high temperature state. When the glass begins to harden, it hardens. The hardened outer layer will prevent the shrinkage of the inner layer, so that the first hardened outer layer produces compressive stress, and then the hardened inner layer produces tensile stress. Because there is compressive stress on the surface of glass, when the external force acts on the surface, it must first offset this part of the compressive stress, which greatly improves the mechanical strength of glass. Glass products treated by such physical treatment are toughened glass. The forming process of bending steel glass includes bending and hot bending. The bending is to press the hot glass into a certain shape by pressing film. The hot bending is to press the glass heated to softening temperature to the bending die by self-weight or close to the air cushion heating furnace.
Uses: Widely used in buildings, automobiles, ships, aircraft, instruments and furniture.