Differences of glass molding processes

Glass is one of the oldest materials known to mankind. Glass was first produced by hand in Mesopotamia and Egypt in 3,000 BC. At that time, glass was mainly used to make small vessels and jewelry. Glass is a material made of quartz sand, limestone and soda with a certain technology by mixing them together. The types of glass differ in the methods of production and the elements added to the basic materials during the manufacturing process. Each epoch and culture had developed its own method and so, over time, the most diverse types of glass were created.

How is glass made?

The individual glass manufacturing components are stored as raw materials in their own silos and barrels. Before the mixing process, the required components are then weighed and automatically mixed in a large basin. In most cases, old glass shards are additionally added to the raw material to save raw materials and, above all, energy. By recycling glass, the melting process of the starting material mixture requires less time and lower temperatures. After the material mixing process has been successfully completed, the mixed materials are transferred to heating furnaces, which are operated with gas or oil, and the melting process is initiated. In this process, the mixture is heated to a very high temperature, blown into the desired shape and then cooled. Such a process can take up to 24 hours.

Shaping glass

The right choice of glass-forming method mostly depends on the target product. We consider the four famous methods known to all manufacturers: Blowing, casting, pressing and drawing. The purpose of each manufacturing process is to give the glass more strength and rigidity.


With this method, the craftsman begins while the molten glass is still in the furnace. Through a tube, the glass is slowly inflated and at the same time formed into the desired shape. Because it is soft, the manufacturer can easily shape, squeeze and cut the glass. During this phase, he puts the glass in the furnace from time to time to keep it soft until the desired shape is achieved. Finally, the craftsman separates the tube from the finished glass with special tongs.


Another way to shape the glass is the pressure method. In this method, the craftsman presses the molten glass into a finished mold with a plunger until the mold is evenly filled. After solidification, the plunger is pulled out again. Typical press items include baking pans, mugs and lighting fixtures.


The buoyancy method or drawing is used to produce flat glass or glass fibers. In this process, the molten glass is introduced in a continuous furnace onto a bath of liquid tin, on which it then floats and spreads evenly. The surface tension of the tin and the liquid glass thus creates a smooth surface. The glass then passes through an annealing furnace where it is cooled down and cut after a visual quality control. The best-known products of float glass include window panes, vehicle panes and safety panes.


In this method, the craftsman uses a special tool to pour the hot liquefied glass into a prefabricated mold and allows it to cool slowly until it solidifies. It is a popular method, which mainly melts used glass to obtain new shapes from it. The best-known products manufactured in this way are lamps and glass products from the chemical and medical industries.  Do you already know our large selection of glass vases? Check us out and get inspired by the great craftsmanship!

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