Effect of Coating Method on Paper Surface Characteristics-A Comparison Between Blade, Film, and Curtain-Coating, 2005 TAPPI Coating Conference

Curtain coating represents a promising high-precision coating technique for a wide variety of applications. It has been applied in the production of speciality papers since the 1970s, but it has only recently been introduced into the production of paper and board grades. This study compares the curtain coating technique with the more traditional blade and film coating techniques in terms of surface characteristics of the coated paper. A 39 g/m² LWC base paper was pilot coated with the three respective coating techniques. The coated papers were analysed using a combination of novel and traditional surface characterisation methods. Optical properties, roughness, coverage, coating mass and thickness distribution as well as compression uniformity were studied. It was found that curtain coating had the highest uniformity in coating thickness and the best coating coverage. Because of the gentle application of the coating onto the base paper, the bulk of the curtain-coated paper was well preserved and the paper was more compressible than the blade- and film-coated papers.