The use of glass has increased dramatically over the years. Modern structural design considerations, aesthetic taste, energy saving and comfort awareness require that the glasses have enhanced strength, safety and thermal performance. This situation requires an increase in the use of heat treated glass.

Principle of heat treatment

        The basic goal of the heat treatment process is to create initial conditions for surface and edge compression. This condition is achieved by first heating the glass and then rapidly cooling the surface. This makes the center of the glass hotter than the surface. As the center cools, it forces the surface and edges into a compressed state. Therefore, this glass can only become Brocken after overcoming this extra surface of compression.

        The heat-treated glass is broken into small, relatively harmless pieces by a tensile force released from the center core of the glass, and this phenomenon of breaking the glass into small particles is called cutting.

Heat treatment process

        The annealed float glass is cut to the desired final size, the edges are stitched or polished and washed. There are two main manufacturing methods for heat treatment. One process heats it in a horizontal position, while the second method moves the glass through the furnace in a vertical position, with each lamp being held by a metal pliers. It is then heated to about 650 degrees Celsius. After the hot glass is taken out of the tempering furnace, it is rapidly cooled (quenched) by uniformly blowing a carefully controlled gas flow from a fixed or reciprocating or rotating nozzle onto both surfaces of the glass.

Response of glass properties to heat treatment

        After heat treatment, color, solar energy, chemical composition, hardness, specific gravity, coefficient of thermal expansion, softening point, thermal conductivity and stiffness remain unchanged. The only physical properties of the change are improved bending and tensile strength, as well as improved thermal and thermal shock resistance. The heat treatment changes the fracture mode of the glass. The fully tempered glass is broken down into relatively small, harmless pieces.