Effect of Coating Technique on Paper Surface Characteristics – A Comparison Between Blade, Film andCurtain Coating

摘要

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