Effects of waste glass or boric acid addition on the stain resistance of polished porcelain stoneware

Abstract

This study evaluates the effects of adding waste bottle glass or boric acid as fluxing agents on the stain resistance of a porcelain stoneware tile body Different amounts of waste bottle glass, 5, 10 and 15 wt. %, were replaced with the same amounts of sodium feldspar in body formulation. In addition, 0.1, 0.3 and 0.5 wt. % of boric acid were added to the standard body formulation. These new compositions were sintered at 1210 and 1220 degrees C with a thermal cycle of 45 min. The densification behaviour of the samples was investigated by determining the water absorption, linear shrinkage and bulk density of the fired samples. The results show that the presence of waste bottle glass or boric acid positively influences the sintering behaviour, increases shrinkage, decreases open porosity and improves the stain resistance with respect to standard bodies.