Some Observations on Density Changes, their Measurement and Influence on the Quality of Container Glass

JSGT 1949 V33 T199-T219

 Using the physical properties of density, and stresses and strains, aided by a limited number of observations on chemical durability, and on thermal expansions, a system of glass control has been instituted which has proved to be of real assistance in studying, improving and maintaining glass quality. Methods for the speedy determination of density, using a simple form of apparatus, are described, and information given regarding the best methods of correlating changes in density with variations of chemical composition, and in turn of tracking down batch changes. The advantages of using “density spread” as a prior indication or warning of possible glass-making troubles ahead are discussed. Whilst the use of physical properties to supplement chemical analyses in obtaining closer control of glass quality is strongly advocated, the fact should be emphasised that this subject is still in its infancy. Too much should not be expected from these early studies of physical properties.

A. T. Coe