The Float Process

Today, almost all flat glass is made using the "float" process. In this process sand, limestone, soda ash, dolomite, iron oxide and salt cake are mixed together and fed into a large furnace, in which they combine, in a process of chemical and physical transformation, to form molten glass. A continuous ribbon of molten glass is fed out of the melting furnace through a "delivery canal" and onto the surface of an enclosed bath of molten tin. The molten glass literally floats on top of the tin, and as it flows along the surface of the tin bath away from the delivery canal, its temperature decreases until it becomes a solid sheet that can be lifted from the tin onto rollers for further cooling, and cutting.

This process produces glass sheets with a uniform thickness and perfectly smooth surfaces that need no further polishing. The resulting glass will then be further treated in various ways to incorporate one or several of the advanced technologies applied to flat glass today, depending on the end-product and application for which it is destined.