Each type of glass is made in a different way. A piece of very thin glass is made in a different way from a strong glass bottle. The liquid glass may be cooled down quickly or slowly to make different kinds of glass. Glass can be shaped in many ways.
Flat, clear glass is called ‘float glass’.
In a factory, ingredients are measured and mixed and then heated up in a furnace (hot oven). As the mixture cools, it is shaped. To make glass for a window, the glass mix is spread over hot liquid metal. It is called float glass because it floats on the liquid metal. The contact between the glass and the metal is perfectly flat.
Glass is shaped when the mix is still runny and hot.
Glass cools quickly so it needs to be shaped before it sets and hardens. Glass can be shaped either by craft workers or special machines.
This bottle was shaped by a mould.
Liquid glass is poured into a mould. As it cools down, air is forced in to make the hollow. The glass hardens and is taken out of the mould.
Glass-making is skilled work.
Glass ornaments are often made by heating, joining and shaping several pieces of glass.
You can blow glass up like blowing up a balloon!
