? The first patent of tempered glass 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. Frederick Siemens of Germany obtained a patent in 1875, and Geovge E. Rogens of Massachusetts of the United States applied the tempering method to glass and lamp posts in 1876. In the same year, HughO'heill of New Jersey received a patent.
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.
Following 1970, British Triplex Company successfully toughened glass with a thickness of 0.75~ 1.5mm with liquid medium, ending the history that physical tempering cannot toughen thin glass, which is a major breakthrough in toughened glass technology.
The history of tempered glass in China began at 1955, with trial production in Hua Yao glass factory and trial production in Qinhuangdao tempered glass factory at 1958. 1965, Qinhuangdao Hua Yao glass factory began to produce military tempered glass. In 1970s, Luoyang Glass Factory took the lead in introducing Belgian tempering equipment. At the same time, the chemically toughened glass of Shenyang Glass Factory was put into production.
Since 1970s, toughened glass technology has been widely promoted and popularized all over the world. Tempered glass has been used in automobile, architecture, aviation, electronics and other fields, especially in architecture and automobiles.