Tempered glass safety glass is a kind of prestressed glass, in order to improve the strength of the glass, chemical or physical methods are usually used to form compressive stress on the surface of the glass, so that the glass first counteracts the surface stress when subjected to external force, so as to improve the impact resistance of the glass. The hot soak treatment is also known as the homogenization treatment, commonly known as "detonation". The hot-dip treatment is to heat the tempered glass to 290 °C±10 °C, and keep it warm for a certain time, so as to promote the nickel sulfide to quickly complete the crystalline phase transformation in the tempered glass, so that the tempered glass with defective quality and may self-explode is artificially broken in advance in the hot dip furnace of the factory, so as to reduce the self-explosion of the tempered glass in use after installation. This method generally uses hot air as the heating medium, which is called "HeatSoakTest" in foreign countries, referred to as HST, and literally translated as hot soak treatment.
1.Why should tempered glass safety glass be homogenized?
The main purpose of tempered glass is to reduce the self-explosion rate of tempered glass. In the national standard GB 15763.2-2005, the "self-explosion" of tempered glass is explained, and nickel sulfide crystals appear in the tensile stress zone of tempered glass, and spontaneous explosion will occur when the crystal is transformed. Therefore, glass tempering furnaces are generally used to homogenize the glass, so that the safety of glass use is improved.
2.The process of homogenization treatment
The process of homogenization treatment of tempered glass safety glass includes three stages: 1heat preservation and cooling, which is similar to the process of tempering the original film.
Heating stage: the heating starts from the ambient temperature of the glass, and stops after all the glass reaches 280 °C, the temperature of the glass surface is not allowed to exceed 320 °C, and the time of the glass surface exceeding 300 °C should be shortened as much as possible, which requires us to heat up more uniformly.
Insulation stage: After all glass reaches 280 degrees Celsius, open the insulation, at least two hours, and keep the surface temperature of the glass in the range of 290 °C ± 10 °C.
Cooling stage: After the insulation is completed, enter the cooling stage, let the glass drop to room temperature, when the temperature in the furnace drops to 70 °C, you can open the furnace door to terminate the cooling output.