Role of moisturising and pressing pressure on ceramic tile properties

The research work is focussing on the role and effect of moisture content obtained from moisturising process and pressing pressure of various clays at firing temperature of 1200 °C. Clays were evaluated for bulk density, two dimensional shrinkage and water absorption. Overall impact of pressing pressure on the clay properties was noted to be greater than the moisture content. Drying bulk density of clays increased with increased in moisture content and pressing pressure. For correlation analysis, all clays showed similar trend, where increase in fired bulk density led to reduction in diameter shrinkage (fired) and water absorption. Proper controlling of the moisture content and pressing pressure are crucial in obtaining the required final size and water absorption of fired tiles. Furthermore, drying shrinkage of clays was considered insignificant with total shrinkage mainly resulted from firing shrinkage. It was also observed that the fired shrinkage in thickness of all clays was greater than the diameter-based fired shrinkage by 2–3%. Therefore, the outcomes of the study provide an insight into the development ceramic tiles body formulation during raw materials selection. The findings are also crucial in designing mould for pressing operation for industrial applications.