Digital Printing of Glass-ceramic Glazes

The outstanding versatility shown by Inkjet printing has turned it into a leading technology in several industrial manufacturing fields of which ceramic tile decoration is a good example. Several papers in literature have set the rheological and fluid dynamics characteristic of the inks and the process parameters required for an optimum ink deposition for ceramic tile decoration. However, there is a lack of studies investigating the conditions for the deposition of glass-ceramic glazes. The glazes considered in the present study are intended for digital injection devices using printheads working in the Drop On Demand (DOD) mode based on piezoelectric elements or other digital injection techniques such as continuous ink jet (CIJ), electrovalves, pistons or others. The purpose of this work is to study experimentally the influence of chemical composition and mineralogy acting on the jettability of a range of glass-ceramic glazes. Relevant parameters like viscosity, surface tension and process parameters such as applied pressure, are discussed on the basis of fluid mechanics parameters and printing diagrams. The specific characteristics of digital glaze deposition technologies (continuous jetting and drop on demand) are discussed and the remaining challenges for future applications of the technology are outlined.