Glass production process flow

The production process of glass is described as follows:

Ingredients: According to the designed material list, all kinds of raw materials are weighed and mixed evenly in a mixer. The main raw materials of glass are: quartz sand, limestone, feldspar, soda ash, boric acid, etc.
Melting: The prepared raw materials are heated at high temperature to form a uniform bubble-free glass liquid. This is a very complex physical and chemical reaction process. The melting of glass is carried out in the melting kiln. There are two main types of melting kilns: one is the crucible kiln, the glass material is held in the crucible and heated outside the crucible. Small crucible kilns only place one crucible, and large ones can have up to 20 crucible. Crucible kiln is gap production, and now only optical glass and color glass are produced by crucible kiln. The other is the pond kiln, the glass material is melted in the pond, and the open flame is heated on the surface of the glass liquid. The melting temperature of glass is mostly 1300~1600゜C. Most of them are heated by flame, and a small amount are heated by current, which is called electric melting kiln. Now, the pond kiln is continuous production, the small pond kiln can be a few meters, the large can be as large as 400 meters.
Forming: The molten glass liquid is transformed into a solid product with a fixed shape. Forming must be carried out within a certain temperature range, which is a cooling process in which the glass first changes from a viscous liquid to a plastic state and then to a brittle solid state. Forming methods can be divided into two categories: artificial forming and mechanical forming.
Annealing: Glass is subjected to intense temperature changes and shape changes during forming, which leave thermal stress in the glass. This thermal stress will reduce the strength and thermal stability of glass products.