DRYING OF A PAPER COATING : EXPERIMENTAL STUDY AND MODELLING

Abstract

This research deals with the physical mechanisms that occur during drying of a paper coating. A study at the local scale of the drying of a paper coating coupled with natural binder (starch) migrations is carried out. In this aim, drying experiments have been realized and lead to the determination of drying kinetics, time evolution of moisture content profiles, and starch concentration distribution at the end of drying. The results obtained allow the modelling to be validated. This model, which is based on diffusive liquid transport, takes into account the shrinkage of the coating and the migration of the different solid components during drying. It leads us to suggest that starch migration occurs until the coating is totally consolidated.

Key words and Phrases:

• pigment coating
• starch migration
• consolidation
• shrinkage
• gel point
• diffusive model