The porcelain tile dry colouring proces

Abstract

The influence of the variables involved in the dry coloring process on the behavior of porcelain tile bodies and the properties of the fired product during different manufacturing stages was examined. The dry-colored spray-dried powders were prepared in which the spray-dried powder characteristics and pigment characteristic were modified. A polished cross-section of a tile obtained from dry-colored granules is found to consist of a light-colored matrix, corresponding to the cross-section of the spray-dried powder granules. The results also show that pigments are classified as those producing loss of tile mechanical strength below 10% and a second group of pigments with losses of 20%. Small changes are detected in the maximum densification temperature for the compositions with 2.0% pigment, though linear shrinkage and bulk density of tile pieces varied between the different colored compositions