INVESTIGATION ON ENAMEL CLAYS1

Functions of clay in enameling and requirements of enamel clays are enumerated. The investigation deals with twelve representative enamel clays, which were examined for water of plasticity, drying shrinkage, modulus of rupture and properties when fired to 1000°C. Using these clays in enamel slips, viscosity, suspension test, and hydrogenion concentration by the indicator method were run. Fineness test, petrographic examination and chemical analyses were made on the clays. They were then tested in a cover coat enamel, subjecting the test pieces to impact test and thermal shock. The results of all the tests are summarized and conclusions drawn therefrom.