Surface characteristics of coating layers formed by coating pigments with different particle sizes and size distribution

The effects of coating color raw material variables were tested on absorbing and non-absorbing base materials. The particle size of the coating pigments was the main variable affecting the gloss of the non-absorbing base materials. Adding binders and increasing the drying temperature has a negative effect on the gloss development of both calendered and uncalendered coating layers. On calendered layers, coating layer films showed more gloss development than for coated papers, especially with coarse particles. Uncalendered calcium carbonate-coated papers have a higher PPS roughness than calendered clay-coated papers. The effectiveness of calendering, as described by “calenderability,” showed an increase in gloss with increasing number of nips, irrespective of size, and size distribution of pigment particles.