Views:6 Author:Site Editor Publish Time: 2019-01-02 Origin:Site
The glass is mainly divided into two major categories: flat glass and deep-processed glass. Want to know if the glass stove cracking will hurt people, and how to avoid blasting the tempered glass, let us take a look.
1.Reduce the stress value
The distribution of stress in the tempered glass is that the two surfaces of the tempered glass are compressive stress, the core layer is in tensile stress, and the stress distribution on the glass thickness is similar to a parabola. The center of the glass thickness is the apex of the parabola, that is, the tensile stress is extremely large; the two sides are close to the two surfaces of the glass are compressive stress; the zero stress surface is located at about 1/3 of the thickness. By analyzing the physical process of tempering and quenching, it can be seen that the surface tension of the tempered glass and the internal tensile stress have a roughly proportional relationship, that is, the tensile stress is 1/2 to 1/3 of the compressive stress. Domestic manufacturers generally set the surface tension of tempered glass to about 100 MPa, and the actual situation may be higher. The tensile stress of the tempered glass itself is about 32 MPa to 46 MPa, and the tensile strength of the glass is 59 MPa to 62 MPa. As long as the tension generated by the expansion of the nickel sulfide is 30 MPa, it is sufficient to cause self-explosion. If the surface stress is lowered, the tensile stress of the tempered glass itself is reduced accordingly, which helps to reduce the occurrence of self-explosion.
2. Uniform stress
The uneven stress of the tempered glass will significantly increase the self-explosion rate, which has reached a level that cannot be ignored. The self-explosion caused by uneven stress sometimes manifests itself very concentrated. In particular, the self-explosion rate of a specific batch of curved tempered glass can reach a shocking severity, and self-explosion may occur continuously. The main reason is the local stress unevenness and the deviation of the tension layer in the thickness direction, and the quality of the original glass film also has a certain influence. Uneven stress will greatly reduce the strength of the glass, which is equivalent to increasing the internal tensile stress to a certain extent, so that the self-explosion rate is improved. If the stress of the tempered glass can be evenly distributed, the self-explosion rate can be effectively reduced.
3. Hot dip treatment
Hot dip treatment is also called homogenization treatment, commonly known as "detonation". The hot dip treatment is to heat the tempered glass to 290 °C ± 10 °C, and keep it for a certain period of time, so that the nickel sulfide can quickly complete the crystal phase transformation in the tempered glass, so that the tempered glass which can be self-explosive after the original use is artificially broken in advance in the factory. In the hot dip furnace, thereby reducing the self-explosion of the tempered glass in use after installation. This method generally uses hot air as a heating medium, which is called "Heat Soak Test" in foreign countries, referred to as HST, and is literally translated as hot dip.