Effect of SiO2/Al2O3 Ratio on Porcelain Tile Glazes for Digital Application

Abstract

Production of porcelain tiles has been increasing rapidly with the increasing demand for both technological and aesthetic features for years. Especially tiles produced with digital applications attract much more attention. Digital glazes (glass-ceramic) can be matte or glossy features. In this study, the effect of the SiO₂/Al₂O₃ ratio on technological properties was examined by keeping other oxide ratios constant in matte glaze compositions for digital applications. Seven glass ceramic compositions were prepared and trials were carried out under industrial conditions. The microstructure was measured with the use of a SEM, phases were determined by XRD, and sintering behavior was characterized by heating microscopy. The color and gloss of glazes were measured using a spectrophotometer and a gloss meter. As the SiO₂/Al₂O₃ ratio decreased, especially the amount of anorthite crystal increased, which resulted in the formation of more matte glaze surfaces. Glaze whiteness and hardness increased due to the crystal formation. As the amount of Al₂O₃ increased, the softening and melting temperature points of the glazes also increased. It has been determined that surface properties can be modified for digital applications by changing the SiO₂/Al₂O₃ ratio.