ABSTRACT
This chapter deals with: Molten glass batches produced continuously in 'tanks' consist mainly of sand, soda ash, limestone and dolomite, a small amount of alumina, a few residual materials and broken glass (cullet). Glass is used in building mainly as flat glass, and for products such as lenses, glass fibres and foamed (cellular) glass. Strength in tension is very dependent on minute flaws, particularly those on surfaces, and even glass of uniform manufacture varies very widely in strength so that safe stresses have to be computed from the results of tests on a very large number of samples. Because double glazing provides better thermal insulation from conducted heat than single glazing, condensation is less likely to form on the room side glass surface of the assembly. Glass fibres are used loose, and in quilts and batts as thermal insulation. The use of a low emissivity coating on the inner pane of a double glazing unit improves the thermal insulation value.
