High borosilicate glass: The thermal expansion coefficient is extremely low, about one third of that of ordinary glass. Strain temperature: 520℃; Annealing temperature: 560℃; Softening temperature: 820℃.
Tempered glass: Good thermal stability, able to withstand three times the temperature difference of ordinary glass and 300℃ temperature difference change.
Second, the application fields are different.
High borosilicate glass: widely used in solar energy, chemical industry, pharmaceutical packaging, electric light source, craft ornaments and other industries.
Tempered glass: widely used in doors and windows, glass curtain wall, indoor partition glass, lighting ceiling, sightseeing elevator passage, furniture, glass guardrail and so on.
Extended data:
Development history of tempered glass;
The development of tempered glass can be traced back to the middle of17th century. A prince named Robert from the Rhine once did an interesting experiment. He put a drop of molten glass into cold water and made a very hard glass.
The first patent for glass tempering was obtained by the French in 1874. Tempering method is to heat the glass to near the softening temperature and immediately put it into a relatively low temperature liquid tank to improve the surface stress. This method is the early liquid tempering method.
In 1930s, Saint-Gobain Company of France, Triplex Company of the United States and pilkington Company of the United Kingdom all began to produce large-area flat tempered glass for automobile windshields. Japan also industrialized the production of tempered glass in 1930s. Since then, the world has begun the era of mass production of tempered glass.
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