We use glass in countless household and industrial items, and most of the time we don’t even realise it’s there. 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 are the stages of glass production.
1.) Sand is well known to be the main ingredient in glass, although other materials are needed. Not any old sand will do and most often Silica is used, in combination with certain amounts of soda ash and also 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.) This mix of minerals is heated up to approximately 1800oC. At such a high temperature all the elements become liquid and all flow together into one mix. This heat is very difficult to achieve and requires powerful specialized furnaces. Although there are now electric furnaces, most glass blowers still prefer to use coals. When the glass mix is in a molten state, it can easily be manipulated and sculpted or blown in to specific shapes. The skills involved in manual glass making takes years to learn and are often passed on through generations.
3.) Once the glass has been shaped it is left 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