FLOAT GLASS PROCESS The term "float" glass derives from the production method, introduced in the UK by Sir Alastair Pilkington in 1959, by which process 90% of today's flat glass is manufactured. The raw materials (soda lime glass, silica sand, calcium, oxide, soda and magnesium) are properly weighted and mixed and then introduced into a furnace where they are melted at 1500 C. The molten glass then flows from the glass furnace onto a bath of molten tin in a continuous ribbon. The glass, which is highly viscous, and the tin, which is very fluid, do not mix so that the contact surface between these two materials is perfectly flat. When leaving the bath of molten tin the glass has cooled down sufficiently to pass to an annealing chamber called a lehr. Here it is cooled under controlled temperatures, until it is essentially at room temperature.
ROLLED GLASS PROCESS This describes glass made through a rolling process, whereby the semi-molten glass is squeezed between metal ro