JNS  TECH

What is Tempered glass ?

• Tempered glass/tempered glass belongs to safety glass. Because during the manufacturing process, compressive stress is formed on the surface of the glass. Whenever the glass is subjected to external forces, it first counteracts the surface stress of the glass itself, thereby improving its load-bearing capacity and pressure resistance. Therefore, it is also known as high-strength glass.

Production process:

• Tempered glass and semi tempered glass are glass obtained by heating ordinary glass or coated glass to the softening point, usually around 700 degrees, and rapidly cooling it to obtain a glass surface with strong and uniform compressive stress, and mechanical strength doubled. Tempered glass with a compressive stress of over 90 MPa.

• 1. Physical tempered glass is also known as quenched tempered glass. It is a process of heating ordinary flat glass in a heating furnace to a temperature close to the softening temperature of glass (600 ℃), eliminating internal stress through its own deformation, and then removing the glass from the heating furnace. Then, high-pressure cold air is blown towards both sides of the glass using a multi head nozzle to rapidly and uniformly cool it to room temperature, thus producing tempered glass. This type of glass is in a stress state of internal tension and external compression. Once local damage occurs, stress release occurs, and the glass is broken into countless small pieces. These small fragments have no sharp edges and are not easy to injure people.

• 2. Chemical tempered glass is strengthened by changing the chemical composition of the glass surface, usually using ion exchange method for tempering. The method is to immerse silicate glass containing alkali metal ions into molten lithium (Li+) salt, causing Na+or K+ions on the surface of the glass to exchange with Li+ions, forming a Li+ion exchange layer on the surface. Due to the smaller expansion coefficient of Li+compared to Na+and K+ions, the outer layer shrinks less and the inner layer shrinks more during the cooling process. When cooled to room temperature, the glass is also in a state of inner layer tension and outer layer compression, similar to the effect of physically tempered glass.

• 3. Place the tempered glass in a heating furnace with a temperature of 500-550 ℃ for 340-360s; Then the heating temperature is set to 700-720 ℃, and the heating time is also 340-360s. When the softening degree is reached, bending is carried out. Finally, rapid cooling is used to generate compressive stress on the glass to enhance its strength.

• Thickness: 5-15mm,
  Min size:220×420mm, Max size 2000 x 3500mm