Adhesion at Toner/Paper Interface in Electrophotographic Printing

In all printing processes, the quality of ink adhesion is of primary importance to ensure the legibility and permanence of the transmitted information. However, contrary to the other processes, which use a fluid ink penetrating the support, electrophotography consists in depositing a fine layer of powder containing pigments and to fuse it onto the paper surface. The mechanisms involved in obtaining good adhesion at the toner/paper interface have thermal, rheological and physico-chemical origins. In this paper, the three main mechanisms of adhesion are reviewed: mechanical anchoring, adsorption and diffusion. Experimental modifications of paper roughness, surface energy and diffusion potential are described and analysed in order to determine which parameter is prevalent to achieve good toner adhesion.