The Rate of Setting of Glass during Working

JSGT_1934_V18_T323_T335

The effects of temperature coefficient of viscosity, heat capacity, thermal conductivity and infra-red radiation were considered. A study had been made of the comparative rate of setting of two colourless glasses and of one of these glasses with four others of similar composition except that they were coloured respectively with 2% of cobalt, ferrous, ferric and manganese oxides. Because of their greater radiating powers, the surface of glasses' containing cobalt, ferrous and ferric oxides set quicker than that of the corresponding colourless parent glass; but the glass containing manganese oxide differed little from the colourless glass. For the purpose of characterising the rate of setting of glass, the symbol Z was proposed, corresponding to the time interval during which the viscosity changes from its initial to its final value while the glass is being worked.

I. I. Kitaigorodsky & N. W. Solomin