Glass is made of a variety of inorganic minerals (such as quartz sand, limestone, feldspar, soda ash, etc.) with a small number of auxiliary materials. Its main components are silica and other oxides. The chemical composition of ordinary glass is Na2SiO3, CaSiO3, SiO2 or Na2O·CaO·6SiO2, etc. The main composition is silicate compound salt, which is a random structure amorphous Solid.
Pyrex glass composition, is a kind of safety glass, use chemistry or physics method, increase the intensity of glass, form compressive stress in the glass surface. When under external force, it will resist eliminating surface stress firstly. So, enhancing the glass itself against wind pressure, heat and cold, impact, etc.
After a little break, the tempered glass will form into different regulated small obtuse angle particle fragments.
However, when the ordinary glass is broken, a sharp like a knife will be formed. Compare with normal glass, the tempered glass is not easy to hurt people. Therefore, it is called a safety glass.
2. Mechanical strength and thermal stability
The defect of common glass quality is bubble, stone, fragile, etc. Air bubbles are hidden inside the glass, which was because of the carelessly dealing during the cooling phase of the manufacturing process. Stone also calls sand grain, It is a solid inclusion in glass, which is an extremely dangerous defect for glass. Not only does it destroy the appearance and optical homogeneity of the glass, and it will greatly reduce the mechanical strength and thermal stability of glass products. Tempered glass is several times stronger than ordinary glass, so tempered glass and ordinary glass prices are different.
3. Tensile strength and impact resistance
Tempered glass is obtained by cutting ordinary annealed glass to the required size, heating it to the near softening point, and then cooling it quickly. After tempered treatment, the surface of the glass forming into compress resisting force stress, and the inside forms tensile stress, so that the performance of the glass can be greatly improved, the tensile degree of resistance is more than 3 times the latter, the impact force of resistance is more than 5 times the latter.
Tempered glass has about five times the bearing capacity than the ordinary glass, but like other kinds of glass, it will break when it is affected by external forces such as collision and scraping. The edge of tempered glass is the part that is more sensitive to external force and it is the weaker area. When tempered glass is broken, it makes a loud noise and the broken particles will drop everywhere. But fragments of tempered glass do not have sharp angles. When ordinary glass breaks, it forms sharp shards and can cause serious damage.
Tempered glass, when the glass is heated to near a softening state, and then instantaneously cool down, a layer of tempered stress is created inside the glass, Increases the resistance of glass surface to pressure and impact. When broken, the glass size as corn gain, it doesn't heart the human body in daily.