How Is Glass Made? | Types and Properties of Glass

Whether in wine glasses, in the windows, in the car, or the thin fiber optic cable, we don’t often realize how many things in our life are made of Glass. Glass has always been considered fragile, but nowadays, even bulletproof Glass are available. But how is Glass made? How sand turns into something that is almost liquid. Let’s find out.

Glass is a completely uniform substance, a solidified melt in which the molecules do not form crystal lattices and have no order. It is precisely this lack of structure that owes its transparency to Glass.

Chemically, Glass cannot be put into formulas because it is made up of mixtures of different compounds. How is Glass made was known thousands of years before we realized what Glass really is.

For our ancestors, it was magic, which radiated through the refraction of light. It was so precious for a long time that ordinary people couldn’t afford glass windows. They covered their windows with sacks or built wooden shutters with small openings in front of them. Only in churches, there used to be stained glass windows. 

In the Middle Ages, Glass was made from quartz sand and wood ash. Lime was used for high-quality Glass along with Quartz sand and potash(washed and evaporated wood ash).

How is Glass made Today is also very similar to how it was made earlier. It usually consists of three basic materials, quartz sand, which contains silicates that are chemical compounds containing silicon and oxygen, lime (calcium carbonate), and soda (sodium carbonate).

Strictly speaking, Glass is not really a solid material at all but is in a state between solid and liquid with special chemical properties. 

Glass is a melting product that is produced at a temperature of around 1600° C. Its special properties include transparency, hardness, and durability. Humans have constantly used glass for 7,000 years.

In the beginning, it was used as jewelry, for the production of elaborate luxury objects and the interior decoration of cultural buildings and palaces.

Today it fulfills important tasks in architecture, technology, science, and everyday life. After all, the raw materials required to produce Glass are almost inexhaustible. In many cases, Glass is, therefore, replacing materials that have become scarcer, such as copper in telecommunications.

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All the ingredients are heated together to 1600° C in the melting furnace of the glass factory until they melt. This liquid is then also called Glass Melt. The hot, liquid glass slides into a huge tub that is 250 meters long and six meters wide so that it does not become a huge lump of Glass, but a windowpane.

This giant tub is filled with liquid tin. Being lighter than tin, the liquid Glass floats like a grease film on top of the tin and cools down very slowly. It creates a long, wide, and completely smooth glass ribbon in the factory and that is how glass is made. It is transported on large rolls and finally cut into large panes by an automatic machine.

We know today that Glass is a hypothermic, solidified liquid. It is melted at around 1600° C, but it is liquid at 1000° C. At normal room temperatures, it is practically a solid body.

It is one of the special characteristics of Glass that the individual states can be repeated as often as required, from solid to liquid. This property allows recycling, reusing used Glass by melting it down.

This property allows the glass artists to use it in almost inexhaustible combinations. The rediscovered technique of fusing glass, in which different glass colors are fused together and in several layers.

This creates luminous glass objects such as glass angels, bowls and jewelry. But also large objects such as door panels and windows. In combination with the oldest and best-known technology, lead glazing, and stained glass, glass fusion is also used.

How is glass made might be the same but there are various new treatments done to enhance the properties of glass, a special process of cooling glass slowly is called Annealing. It also makes Glass more break-resistant. It is used for glass furniture, large glass doors, and car windows.

There is another process called Tempering, which changes the properties of the Glass in such a way that it can no longer be cut or ground. And if it does break, it crumbles into tiny crumbs. It is much more practical because nobody gets injured if the glass breaks.

At the jewelry stores, banks, and also in the cars of politicians or pop stars, the window panes are often made of bulletproof glass. This is not just an insanely thick glass pane. Bulletproof Glass consists of many layers of super tear-resistant film and normal glass panes.

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The film and Glass are always on top of each other in alternation. Then the layers are baked together in the oven. The baked foil-glass sandwich becomes so firm that it cannot even be shot through by a bullet. That is how bulletproof glass is made.