glasframställning

Glasframställning, or glassmaking, is the process of producing glass. This ancient craft involves heating a mixture of silica sand, soda ash, and limestone to very high temperatures until it melts into a molten liquid. The exact composition can be varied to achieve different properties in the final glass. Other materials may be added to impart color, such as metal oxides.

Once molten, the glass can be shaped in several ways. Traditional methods include blowing, where a gather of molten glass is inflated with air using a blowpipe, or pressing, where the molten glass is forced into a mold. For flat glass, such as window panes, the float glass process is commonly used, where molten glass is poured onto a bed of molten tin, allowing it to spread and cool into a perfectly flat sheet. Glass can also be cast or drawn into fibers.

After shaping, the glass is typically annealed, a controlled cooling process that relieves internal stresses and prevents cracking. This is often done in a lehr. Various finishing techniques can then be applied, including cutting, grinding, polishing, and decorating. The versatility of glass, from its transparency and inertness to its strength and aesthetic appeal, has made glasframställning a vital industry for millennia, serving purposes ranging from everyday containers to intricate works of art and essential building materials.