The Grindability and Optical Properties of Glass-Ceramic Frits for Inkjet Printing

Decoration is the most critical feature in determining the final quality of ceramic tiles. Traditional decoration techniques, such as screen printing and rotocolor, have been transitioned to inkjet printing due to technological improvements in the ceramic industry. Inkjet technology has enabled an unlimited variety of decorative designs, facilitated the efficient storage of designs, and made it possible to apply decoration without direct contact with the product. Additionally, inkjet decoration enhances the natural appearance of the image. Inkjet printers use inks in which inorganic particles are suspended in a carrier medium. Recently, effect materials that provide surface properties such as matte and gloss have also been utilized. The prepared effect material exhibits an average particle size (d50) of 0.3-0.6 μm, which is required to prevent clogging of the nozzle head in the inkjet printer. Effect materials are needed to demonstrate optimum viscosity, density, and particle size distribution, ensuring their suitability for use in inkjet printers. This study examines the particle size distribution, milling behavior, rheological properties, and morphological characteristics (as observed by SEM) of transparent, opaque, and matte glass-ceramic frits used in wall and floor tiles. Furthermore, optical properties were measured using gloss meters and colorimetric devices. The results demonstrate that the investigated frits fulfill the particle size and rheological requirements for jetting in inkjet printers, achieving d90 values below 1 μm to prevent nozzle clogging and post-dilution viscosities within the ideal range of 15–25 mPa·s. The frits were determined to be suitable for application on wall and floor tiles.