Automotive safety glass is divided into laminated glass, tempered glass and tempered glass of the three regions, from the original glass to the secondary processing. Automotive front windshield commonly used better security laminated glass, in addition to the front windshield, the automotive glass are tempered glass.
Simply put, the original piece of glass after heating, blowing cold air and other processes that produce after the glass. Ordinary glass after the steel, not only increased strength, and the internal structure has changed. When the case of destructive external shocks, resulting in glass rupture, it will not form a sharp knife-edge, but the fragmentation of many small pieces, each piece is the original cold air formed when the steel point. Technically, the size of these debris is required, they can not be too big nor too small, too large to form sharp edges and corners, do not achieve the security role; too small will form a powder, hurt the eyes of passengers.
Laminated glass, as the name implies, is made of two or more layers of glass, which is safe because there is a layer of PVB film between the glass (a kind of adhesive, highly flexible polymer material). When the glass fragmentation, so that the glass fragments will not be scattered and hurt, and to ensure that the driver has a certain field of vision to deal with emergencies. In addition, after adding PVB film laminated glass flexibility, enhanced penetration resistance, which to some extent to prevent the driver in the emergency brake due to inertia is too large and the head out of the window.
Regional tempered glass is a kind of tempered glass, use it as the car front windshield, security than flat glass, but the car manufacturers in terms of lower cost. Ordinary tempered glass is not suitable for the front windshield, because it will be broken into a pile of broken end, like waterfalls generally diarrhea, blocking the driver's attention, is not conducive to emergency treatment. In this way, some middle and low-grade cars on the use of regional tempered glass, due to the principle of regional steel, when the glass fragmentation, the driver vision part of the glass will form a lens-like fragments, to ensure that the driver has a vision, Accident occurred.