Glass Making Revealed
admin | November 27, 2009
Glass has been used for hundreds of years in millions of different items and it is an amazing material that is often taken for granted. We use it in our cars, buildings, light bulbs and wine glasses, but few people know exactly how glass transforms from raw materials into the functional molded end products. Here is a breakdown of the steps required in glass making.
1.) Sand is well known to be the main ingredient in glass, although other materials are needed. The most common form of sand used is called Silica, and this is combined with specific amounts of soda ash and limestone. The quantities of the ingredients effects the qualities of the glass, and other materials can be added to change the colour of the glass or alter its strength etc. For example, a glass blower might add a small amount of red dye to the mix to make pink champagne glasses.
2.) Around 1700oC is the temperature that the mixture is heated to. When it reaches this temperature it forms a fluid liquid and all the added elements blend into one. This heat is very difficult to achieve and requires powerful specialized furnaces. Traditionally the glass mix was heated in coal-powered furnaces, however electric furnaces are increasing in number all the time. When the glass mix is in a molten state, it can easily be manipulated and sculpted or blown in to specific shapes. This is a skill that takes years to master and is very easy to get wrong.
3.) After the glassblower has shaped the piece, it is then allowed to cool down. This is a very important step as the rate at which the glass cools has a large influence on the refractive index of the glass and the density of the glass. For example, whisky glasses are often cooled slowly as this makes them less susceptible to scratches, although the refractive index is slightly lower than other types of glass
