Color, ceramic pigments and decoration techniques

Contact person: Michele Dondi, Davide Gardini
Involved persons: Chiara Zanelli, Chiara Molinari

Decoration has a growing importance, as a means to add value to ceramic products, as fundamental is innovation in the application techniques and materials used by the industry.

CNR-ISTEC is contributing to set up new decoration technologies (e.g. ink jet printing) by developing inks, powders and their functionalization and synthesis procedures, in order to improve yield, stability and durability in the ceramic process . Ceramic pigments are coloured crystals that are dispersed into a vitreous matrix, in which are insoluble, to impart colour by heterogeneous mixture. Ceramic pigments are widely used to colour tiles, tableware, sanitaryware, glazes and glasses.

CNR-ISTEC is developing novel pigments, in collaboration with universities and companies in Italy and abroad, in order to improve optical properties, stability in the ceramic process, industrial manufacturing and cost, health and safety.

Equipment and processes

Decoration techniques: characterization of composition, particle size distribution, chemico-physical and rheological properties of products for ceramic decoration (inks, powders, grains, vehicles, ecc.) in order to understand and improve their technological behaviour. Rheological tests (viscosity, thixotropy, yield stress, viscoelasticity); measurement of zeta potential, electrical conductivity, stability over time, surface tension; particle size distribution (Sedigraph and DLS); specific surface; chemical analysis ICP-OES; colourimetry; simulation of the tilemaking process.

Ceramic pigments: combined characterization of crystal structure, optical properties, microstructural features and behaviour in the ceramic process in order to comprehend the relationships between structure, colour and technological performance. X-ray diffraction (XRPD and HT-XRD) with full profile Rietveld refinement (synchrotron light and neutron diffraction too); optical spectroscopy and colourimetry (DRS); scanning electron microscopy (SEM) and microanalysis (EDS); application in glazes and glassy coatings by simulating the manufacturing process of ceramic tiles and sanitarywares.

Main collaborations

Department of Physics and Earth Sciences, University of Ferrara;
Department of Chemistry and Earth Sciences, University of Modena and Reggio Emilia;
UJI Universitat Jaume Castellon de la Plana Spain.