Digital decoration for ceramic tiles: The effect of glazes particle size distribution on the inkjet decoration

Abstract

After the consolidation of the digital decoration technology in the ceramic tile industry, digital glazing is the next step toward a fully digital decoration line. To make this possible, a key requirement, regarding glaze suspensions characteristics, is the reduction of the actual particle size of the solids. In this context, the objective of this work is to evaluate the effect of the particle size distribution of frits used to produce a transparent glaze on the glaze layer characteristics and the ink behavior over the same. A frit was milled under different conditions. The milling process has mainly reduced the size of the larger particles, leading to narrower particle size distributions. As the distribution curves narrowed, the particles packing efficiency in the glaze layer decreased. For these more porous layers, faster ink absorption into the surface pores and a consequent more limited ink spreading were observed, which leaded to the production of smaller dots. Thus, changes in granulometry of the glaze raw materials affected not only the glaze layer porous structure, but also aspects of the image quality.