Glassmaking Process Research Articles

Current Trends in Glass Technology

Technological developments in glass today are based on increased laboratory research on the nature of the glass-making process, and the use of such tools as phase equilibrium diagrams and petrographic methods. Colorants and their effects upon glass are discussed. The relative protective effect of different colors of commercial glasses indicates the superiority of amber. Glass durability is indicated as having been a problem now under control. Strength is discussed as the most important factor. Automatic inspection for elimination of defects, increased use of coatings for surface protection, better container designs for more efficient use of available material, and new surface treatments indicate a good probability of increased glass strength.

RECENT STUDIES OF THE FUNDAMENTAL PROCESSES UNDERLYING GLASSMELTING*

ABSTRACTIn normal glassmaking processes not one of the alkaline carbonates is decomposed by heat alone, whereas at 800°C their reaction with silica proceeds rapidly. Calcium carbonate, on the other hand, decomposes completely at 610°C; hence it is almost entirely thermal and does not rise by interaction with silica. There is evidence that in mixtures of sodium carbonate, calcium carbonate, and silica the shrinkage and sintering of the mass at 600°C and 750°C are due entirely to reaction of the soda and silica, the calcium acting as it does in the simple calcium carbonate and silica mixtures.