The Difference Between Tempered Glass And Semi-tempered Glass
Tempered glass is a kind of ordinary flat glass formed after heat treatment. It forms a compressive stress layer on the surface of the glass, with increased mechanical strength and heat-resistant impact strength, and a special crumb state. Steeling is the rapid and uniform heating of ordinary glass to near the softening temperature, and then the appropriate cooling rate so that the glass is rapidly and uniformly cooled (hardened), the cooling of its internal molecular structure changes dramatically, the formation of compressive stress on the surface of the glass, the formation of tensile stress; When damaged, the compressive stress on the glass surface should be offset first, thus improving its mechanical strength and increasing the number of broken particles, so that the glass has security. The strength of FRP is several times that of ordinary glass, more than 3 times that of tensile properties, and more than 5 times that of impact resistance. FRP is not easy to break, and even if it breaks, it forms a kind of particle without sharp angle, which greatly reduces the harm to human body.
The processing principle of semi-tempered glass is similar to tempered glass and also cools more slowly than tempered glass. It is stronger than tempered glass, about twice as strong as ordinary glass. However, the fragments are larger when broken, similar to annealed glass, and cannot be used as safety glass.
Compared to tempered glass, semi-tempered glass is more self-extinguishing and has relatively better flatness.
The higher use temperature of semi-tempered glass is about 260℃.
The surface stress of semi-tempered glass is 24-60Mpa (over 90Mpa for tempered glass)
Some parts of the building to install glass does not involve personal safety, but also need to install tempered glass to improve the wind pressure strength and hail ability, but also hope that once the accidental rupture of the glass can not all broken down, or require the glass deformation as small as possible, these parts can be installed semi-tempered glass. But the fragments are larger after breaking, similar to annealed glass, can not be used as safety glass. Semi-tempered glass bending degree disturbance is less than tempered glass, but its resistance to thermal shock, wind load, external object impact and other performance are better than annealed glass.
Tempered and semi-tempered glass shall not be cut, drilled or ground after heat treatment. At the same time, care should be taken when sandblasting or acid etching operations are carried out, as these operations will reduce the thickness of the internal stress layer of the glass, thus weakening the strength of the glass.