The Effect of Boric Oxide on the Rate of Melting and on some Physical Properties of Colourless Bottle Glasses

JSGT 1929 V13 T248-T262

Up till quite recently the use of substantial proportions of boric oxide in glasses has been confined to those needed for chemical and heat-resisting purposes and for types of optical glass. It is quite true that both in America and in England glass batches containing borax have at times been employed in tank furnaces melting bottle glass, but the amounts have been very limited and no investigation had been vigorously carried out to ascertain if, and how far, boric oxide was of advantage in such glasses. The reason was partly economic. The cost of borax and boric acid has until comparatively recently been too high to permit of its use in mass production glass. The recent very substantial fall in price of boric oxide compounds (the price of borax now being only very approximately one-half of that prevailing 10 years ago) has changed the aspect of the problem, and during the past 18 months or more experiments have been proceeding on the large scale in America to determine the value of borax in melting bottle glass, particularly colourless bottle glass.

Violet Dimbleby, Michael Parkin, W. E. S. Turner & Francis Winks