Glass production process includes: batching, melting, forming, annealing and other processes.
The following are introduced separately:
1. Ingredients, according to the designed material list, weigh all kinds of raw materials and mix evenly in a mixer.
The main materials of glass are quartz sand, limestone, feldspar, soda ash, boric acid, etc.
2. Melting, the prepared raw materials are heated at high temperature to form uniform glass liquid without bubbles. This is a very complex physical and chemical reaction process. Glass is melted in a furnace. There are two main types of melting kilns: one is crucible kiln, in which glass is stored and heated outside the crucible. A small crucible kiln has only one crucible, and a large crucible can have as many as 20 crucibles. Crucible kiln is a gap type production, now only optical glass and color glass are produced by crucible kiln. The other is a tank kiln, where the glass material is melted in the kiln and the open fire is heated on the top of the liquid glass. The melting temperature of glass is mostly 1300-1600 C. Most of them are heated by flame, but a few are heated by electric current, which is called electric melting kiln. Now, the kilns are continuous production, small kilns can be several meters, large can be more than 400 meters.
3. Forming is the transformation of melted glass into solid products with fixed shape. Forming must be carried out within a certain temperature range. This is a cooling process. Glass is first transformed from viscous liquid to plastic state and then into brittle solid state. Forming methods can be divided into artificial forming and mechanical forming.