Qinhuangdao Aohong Glass co.,ltd

How to Solve the Explosion of Tempered Glass?

publisher: AoHong Glass
Time: 2018-05-16
Summary: Tempered glass is actually a kind of prestressed glass. In order to increase the strength of glass, chemical or physical methods are usually used to form compressive stress on the glass surface. When the glass receives external force, it first counteracts the stress of the surface layer, thereby increasing the carrying capacity and strengthening the glass's own resistance. Wind pressure, cold and heat, impact and so on.

How to Solve the Explosion of Tempered Glass?

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Tempered glass is actually a kind of prestressed glass. In order to increase the strength of glass, chemical or physical methods are usually used to form compressive stress on the glass surface. When the glass receives external force, it first counteracts the stress of the surface layer, thereby increasing the carrying capacity and strengthening the glass's own resistance. Wind pressure, cold and heat, impact and so on.

Hot dip treatment, also known as homogeneous treatment, commonly known as 'detonation'. The hot-dip treatment is to heat the tempered glass to 280°C-300°C and hold it for a certain period of time, prompting the nickel sulfide to quickly complete the crystal phase transformation in the tempered glass, so that the tempered glass that may be used for explosion after being used is artificially broken in advance in the factory. In a hot dip furnace, the self-explosion of the tempered glass in use after installation is reduced. This method generally uses hot air as a heating medium, and is called 'Heat Soak Test' abroad, abbreviated as HST, and is literally translated as hot dip treatment.

In principle, hot-dip treatment is neither complicated nor difficult. However, it is very difficult to actually achieve this process index. Studies have shown that there are many specific chemical structural formulas for nickel sulfide in glass, such as Ni7S6, iS, NiS1.01, etc. Not only do the ratios of various components vary but they may be doped with other elements. Its phase change speed is highly dependent on the temperature level. Studies have shown that the phase change rate at 280°C is 100 times that at 250°C, so it must be ensured that each piece of glass in the furnace experiences the same temperature regime. On the other hand, on the one hand, the temperature of the glass with low temperature is insufficient for the holding time, nickel sulfide cannot completely phase change, and the effect of hot dipping is weakened. On the other hand, when the temperature of the glass is too high, it may even cause reverse phase transition of the nickel sulfide, resulting in a greater risk. Both of these conditions will lead to hot dip treatment and even counterproductive. The uniformity of the temperature during the operation of the hot dip furnace is so important that the temperature difference in the furnace during the hot dip insulation of most domestic hot dip furnaces even reaches 60°C. It is not uncommon for the imported furnace to have a temperature difference of about 30°C. Therefore, although some toughened glass is treated by hot dipping, the rate of self-detonation is still high.

In fact, hot-dip processes and equipment have also been continuously improved. The holding time of the German standard DIN 18516 in the 90th edition is 8 hours, while the prEN 14179-1:2001(E) standard reduces the holding time to 2 hours. The effect of the hot dip process under the new standard is very significant, and there are clear statistical indicators: one case of bleed can be reduced to 400 tons of glass after hot dipping. On the other hand, the hot dip furnace is also constantly improving the design and structure, heating uniformity has also been significantly improved, and basically can meet the requirements of the hot-dip process.

Although the hot-dip treatment does not guarantee that the self-explosion will never occur, it does reduce the occurrence of self-detonation and actually solves the problem of self-detonation that plagues all parties involved in the project. Therefore, hot dipping is the most effective way to completely solve the problem of self-detonation in the world.

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