Considerations for Thermally Engineered Coated Printing Papers: Focus on Electrophotography

摘要

This work considers the thermal properties of the coating layer and illustrates its role in respect to toner adhesion as a print quality parameter in the electrophotography process. Three types of coating pigments are studied: ground calcium carbonate, a very porous modified calcium carbonate (MCC) and talc. Temperature gradients within the coating and base sheet substrate, and fusing nip conditions, are studied adopting finite element simulation. Toner adhesion is measured by a tape test on laboratory coated paper samples. The simulation of the fusing nip shows advantages of having a thermally insulating MCC coated substrate. The local temperature gradients are beneficial for the fusing process and the base paper is shielded, thus minimizing heat losses. It is recognized that a smooth and even printing surface, in combination with an insulating coating structure, could be used to lower the specific energy required to fuse toner, provided the surface continuity is sufficient.