Take high quality sand, soda ash, limestone, saltcake and dolomite and melt at white heat to a highly viscous consistency. Let the mixture digest for a time - and you are well on the way to making one of the world's most important materials. This is the basic composition of float glass, one of the greatest of all industrial process inventions, comparable with Bessemer's innovations in steel manufacturing. In fact, this is the formula for many types of mass-produced glass; except that float demands highly exacting standards of quality, care and control unheard of in other everyday uses of glass.
Material
|
Glass Composition
|
Reason for Adding
|
Sand
|
72.6
|
-
|
Soda Ash
|
13.0
|
Easier melting
|
Limestone
|
8.4
|
Durability
|
Dolomite
|
4.0
|
Working & weathering properties
|
Alumina
|
1.0
|
-
|
Others
|
1.0
|
-
|
