Analysis of the Processes of Forming and Consolidation in Blade Coating, 1995 Coating Fundamentals Symposium Proceedings

A base paper for lwc was blade coated in a pilot coater. The mass distribution and surface profile of the coating layer were measured. Based on these measurements, the surface profiles of the base paper at the moment of form-ing the coating layer beneath the blade tip and in the dry final coated sheet were calculated. The model for the analysis is outlined. The calculations showed that the compression of the base paper beneath the blade tip was substantial and that the fraction of the coating layer which remained above the peaks in the base paper surface was large. This suggests that blade coating is not a simple void-filling operation where the blade rests on the compressed peaks in the base paper surface during the forming of the coating layer. In the final coated material, the amplitude of the surface pro-file in the base paper was found to be affected both by the compression beneath the blade tip and by the interaction between the water in the wet coating layer and the base paper during the process of consolidation. At a high blade pressure (low coat weight), the compression was the controlling factor. Keywords: Coatings, coated papers, blade coating, form-ing, consolidation, surface roughness, mass distribution, base papers, mathematical model.