FLOW PROPERTIES OF RAW GLAZE SUSPENSIONS

Abstract

The research deals with the study of the flow properties of raw glaze suspensions used in the application of sanitary ware and porcelain. The relation between the shear stress and strain rate for a certain glaze of a known recipe applying different particle sizes was determined, using different volumetric concentrations. It was deduced that these suspensions follow real plastic fluid behaviour.

Also a relationship between the apparent viscosity, yield stress, concentration and particle size was determined. A study of the effect of the mentioned variables on the constants in the relationship between stress and strain was performed. Also a study on the effect of temperature and aging on that relationship was performed, hence the effect on the apparent viscosity and yield stress on the different suspensions too. The results clarified that a decrease in particle size, increase in volumetric concentration, decrease in temperature and decrease in aging lead to a

higher yield stress and higher viscosity. Also the minimum particle size, and maximum aging and the concentration values were determined such that after these values the variables have no effect. It was also determined that glaze slips aged for 8 weeks followed the generalized friction factor-Re number equation f=16/Re under all conditions investigated during laminar flow.