What is the manufacturing process of glass?

1. Ingredients, in accordance with the design of a good material list, will be a variety of raw materials weighed in a mixer mixer. The main raw materials of glass are: quartz sand, limestone, feldspar, soda ash, boric acid and so on.

2. Melting, the matched raw materials after high-temperature heating, the formation of uniform bubble-free glass liquid. This is a very complex physical and chemical reaction process. Glass melting in the kiln. There are two main types of kilns: one is the crucible kiln, the glass material in the crucible, outside the crucible heating. A small crucible kiln holds only one crucible, while a large one can hold up to 20 crucibles. Crucible kiln is a gap production, now only optical glass and color glass using crucible kiln production. Another is the pool kiln, glass material in the kiln pool melting, open flame in the glass surface of the upper part of the heating. Most of the glass melting temperature in 1300 ~ 1600 ゜ C. Most of the flame heating, there are a small number of electric current heating, known as electric melting kiln. Now, the kiln are continuous production, small kiln can be a few meters, large can be as large as more than 400 meters 2.

3. Forming, is the melted glass liquid into a solid product with a fixed shape. Forming must be in a certain temperature range can be carried out, this is a cooling process, the glass first from the viscous liquid state into a plastic state, and then into a brittle solid state.

4. Annealing, glass in the molding over into the intense temperature changes and shape changes, this change in the glass left thermal stress. This thermal stress will reduce the strength and thermal stability of glass products. If the direct cooling, it is likely that in the cooling process or later storage, transportation and use of their own rupture (commonly known as glass cold burst). In order to eliminate the cold burst phenomenon, glass products must be annealed after molding. Annealing is in a certain temperature range of insulation or slow cooling for a period of time to eliminate or reduce the thermal stress in the glass to the permissible value. In addition, some glass products in order to increase its strength, can be stiffened. Including: physical stiffening (quenching), used for thicker glasses, desktop glass, automotive windshields, etc.; and chemical stiffening (ion exchange), used for watch watch glass, aviation glass, etc.. The principle of stiffening is to generate compressive stress on the surface layer of glass to increase its strength.