Development of lightweight porcelain stoneware tiles using foaming agents

Recent market trends for porcelain stoneware tiles indicate that there is a growing interest for lightweight products, to be used vertically, in internal walls or ventilated facades. The decorative and structural functions have now been coupled with additional features, such as thermal insulation. The optimization of all functionalities depends on a careful control of porosity, in terms of overall amount, size and morphology. In this paper, we propose fundamental correlations between mechanical properties, water absorption, porosity and technological aspects, and particle size and the amount of foaming agent (SiC). The data indicate that the addition of SiC powder with a size < 10 μm enables the fabrication of tiles possessing a suitable strength, negligible water absorption and a weight reduced by 26%. The loss of mechanical strength of the tiles and their pyroplastic deformation controls the maximum attainable decrease in weight.