The differences between semi-tempered glass and tempered glass

Tempered glass is actually a type of prestressed glass. In order to increase the strength of the glass, chemical or physical methods are usually used to form compressive stress on the surface of the glass. When the glass is subjected to external force, the surface stress is first offset, thereby improving the bearing capacity and improving the tensile strength. There are main two advantages of tempered glass. The first is that the strength is several times higher than that of ordinary glass, the bending strength is 3 to 5 times that of ordinary glass and the impact strength is 5 to 10 times that of ordinary glass.This improvement for the strength also means higher security. Safety is the second major advantage of physical tempered glass. Its increased load carrying capacity improves the fragile nature. Even if the tempered glass breaks down, it will show small fragments without sharp angles which means the damage to the human body is greatly reduced. The quenching and heat resistance of tempered glass is 2 to 3 times higher than that of ordinary glass, and generally can withstand temperature difference changes of 150 C or more, which has obvious effects on preventing thermal cracking.

Semi-tempered glass is also called heat strengthened glass which is between ordinary flat glass and tempered glass. It has the characteristics of high strength of tempered glass. At the same time, it is more flat than tempered glass and not easy to self-explode. It also avoid the disadvantages of overall crushing if broken. When the semi-tempered glass breaks, it is radially radial cracked along the crack source, and generally there is no tangential crack propagation, so the whole does not collapse after the damage. Semi-tempered glass is suitable for curtain wall and exterior window in buildings. It can be made into semi-tempered coated glass with image distortion better than tempered glass. However, it should be noted that semi-tempered glass is not included into the safety glass range. As it is broken, there are still sharp fragments that may injure people and cannot be used in skylights and occasions where human impact may occur. The surface compressive stress of semi-tempered glass is between 24MPa and 69Mpa, and the surface pressure of tempered glass should be greater than 69MPa. The production process of semi-tempered glass is the same as that of tempered glass. The wind pressure is only different in the quenching station, and the resistance to quenching and heat is less than that of tempered glass.