Glass production: From traditional craftsmanship to industrial processes
Glass production is an old trade which required a great deal of specialist knowledge as well as a high level of manual skill. We are not talking about the manufacturing of flat glass, for example for window panes. Certainly that is an art in itself, as it does not depend only on the right mixing ratio.
The real skill is to turn the liquid glass into a product. But let us look at modern, industrial glass production. It is fully automated and takes place in seven steps.
Let's get started: First the batch is prepared. The glass materials are weighed and mixed well. Then these are transported in a container on a conveyor belt and into the furnace.
In the oven, the batch is melted at about 1,200 degrees Celsius. These high temperatures are required to ensure that all materials react with each other to form the molten glass.
The problem: Bubbles will form. Just a normal part of the process, the experts say, and refine or "fine" the glass. There are special agents for glass fining. Essentially these are based on the principle that small bubbles are swept along by large bubbles which rise more quickly. The fining agent forces this process.
After fining, the glass is shaped. The details of this step depend on the type of glass that is produced. Then the glass is allowed to cool down.
Depending on the glass type and intended use, this takes between half an hour and the length of a football match with one extra time of about 10 minutes. Once cooled, the glass is examined by quality control.
If there are any defects, it's all over for the glass: It is crushed, processed and reintroduced into the manufacturing process. Finally the finishing: There are different ways for glass finishing, including modern laser technology.