Float glass: perfection produced by floating
The term already explains: Float glass actually describes "floating" glass. This does not refer to a boat made from glass but the manufacturing process of the glass. Float glass simply refers to flat glass literally produced while floating.
Float glass is manufactured continuously. Pure glass melt is introduced into a bath of hot tin at a temperature of 1,100 degree Celsius. One needs to imagine this bath to represent a liquid conveyor belt where the glass is introduced at one end.
The hot pasty glass matter is markedly lighter than tin. It floats on the surface and can spread like an oil film. A so-called glass film then forms on the tin. While travelling from one side of the belt to the other, it cools down to about 600 degree.
The glass is already firm now and can be carefully cooled down in an appropriate "oven". Quite contrary to the common hectic pace, slowness is called for here. Cooling the glass too quickly would cause tensions in it.
At the end of the process, the glass is cut to the standard size for flat glass sheets. The special feature in manufacturing: The surface tension of tin and glass provide for a very smooth and clean glass surface.
Float glass has thus meanwhile become the most used basic glass for nearly any application. It can now be processed further with the various flat glass processing machines.