Improvement of the mechanical and aesthetic properties of a coating by inkjet technology

Different amounts of ink, made up almost entirely of a frit that devitrified abundant small crystals of anorthoclase, were applied by inkjet printing onto a traditional unfired glaze substrate. The rheological properties of the ink and porous texture of the unfired glaze substrate were characterized. The fired coatings were analyzed by SEM–EDX to determine the elemental composition at different surface depths, and their microstructure was observed. The results confirmed the validity of the ink penetration model, developed in a previous study, for describing the composition profile in inkjet coatings as a function of the applied amount of ink and pore size and volume in the unfired glaze substrate relative to average ink particle size. Microhardness and indentation modulus of the fired glaze substrate without an ink application and of the fired ink‐containing coatings were determined. The values of these properties were verified to fit a Weibull distribution function. The coatings containing an ink application at 400 and 600 dots per inch (dpi), respectively, displayed the best mechanical behavior. The study confirmed that inkjet printing a suspension with appropriate physico‐chemical characteristics onto an unfired glaze substrate substantially improved the aesthetic characteristics and mechanical properties of the resulting fired coating.