Glass is a necessary part of the doors and windows, the early construction of doors and windows were using single-layer ordinary flat glass only, nowadays,insulating glass, laminated glass, bullet-proof glass are developed for safety purpose, Most of today’s doors and windows are using tempered glass.
First, how to distinguish between tempered glass and ordinary glass?
1, look at the glass logo
See if there are 3c marks(or other markes showed tempered or toughened glass) at the corner of the glass, most tempered glass has 3c marks. generally,the first step of the Tempered glass processing is that float glass is cut into the required size, and then grinding, cleaning, with ink printing the national compulsory certification CCC mark,
after the tempered furnace process, the finished glass can not be cut or driiled or any other processing works. And ink in the general situation after the high temperature is not scrapped off. (If your 3C logos on the glass can be wiped ,that is not tempered glass for sure)
2, to see if there are slight deformation
From the side to see whether the glass is slightly deformed, because the glass through the high temperature firing, there will be a slight deformation of the phenomenon, which can only be seen from the side of the glass, it is not easy to see in the right front of the glass
3, look at the glass fragments
Ordinary glass is broken from large sheet into sharp angles, easy to hurt.while Tempered glass is broken into granular, corners are blunt, not easy to hurt.
Second, Usually tempered glass are in flat shape or curved shape,and more commonly used flat tempered glass thickness are 4,5,6,8,10,12,15,19 mm.
Third, two different methods to make tempered glass:physical and chemical
Physical tempered glass is to use quenching method or air-cooled quenching method to make ordinary flat glass or float glass into tempered glass
Chemical tempered glass is the ordinary flat glass or float glass through ion exchange method, the glass table,the Surface molecules change, so that the surface of the glass layer to form a layer of stress treatment processing.
Fourth, the characteristics of tempered glass:
1, high impact strength
4 to 5 times higher than ordinary glass ; bending strength, 5 times higher than ordinary flat glass; thermal stability, and can withstand the temperature difference of 200 ℃; smooth, transparent, non-cutting and so on. In the case of super impact damage, the fragments were dispersed into Small granular, no sharp edges and corners, it is also known as safety glass.
2, the glass thickness will be slightly thinner after tempered process
The reason is that after the hot-melt softening of the glass, it is cooled by the strong wind force so that the crystal space inside the glass becomes smaller and the pressure becomes larger, so that the glass is thinner than before.
generally speaking,for 4-6mm glass,it is 0.2-0.8mm thinner after tempered,while for 8-19mm it is 0.9-1.8mm, which depends largely by the equipment.