Relief decorating of ceramic articles using screen printing processes

Abstract

A process for a production basis relief decorating of ceramic articles. In place of conventional, manual application of relief features, the process provides for a special technique for screen printing of relief features onto the surface of a transfer decal sheet, typically a decal sheet that has previously been printed with a conventional, two-dimensional primary design. The new process includes a screen printing stencil of unusual thickness, at least 0.015' and up to as much as 0.125', characterized by having unrestricted non-convergent through openings. Ceramic inks are formulated to heavy viscosity, having a characteristic comparable to peanut butter, with a viscosity in excess of one million cps. The ink is flow resistant in character, and is forced through the stencil openings by a slow-moving squeegee. The squeegee action is such as to provide increased dwell time of the ink with the surface of the transfer decal paper, before lifting of the stencil. The printed design is transferred to a ceramic article from the decal sheet, and is then fused to the ceramic article by kiln firing in the usual way. The relief design elements stand out prominently in three dimensions on the ceramic article. Extraordinary production economies can be realized by the practice of the invention.