Characterization of thin pigment coating layers produced by foam coating

Foam coating is a promising method for applying a thin pigment layer of nanoparticles on a paper web. The interest in applying a low coat-weight coating layer arises from the need to create new functional surfaces using small amounts of new, typically expensive nanoparticles. The characterisation of thin pigment layer properties is more demanding than analysing traditional pigmented coatings layers because of the low coat weight (0.3-2.0 g/m2) and a corresponding low layer thickness of 1 µm or less. This characterisation requires surface sensitive measuring techniques and a combination of different microscopic and spectroscopic surface analyses. In this study, the pigment layer structure and chemical properties of nanosilica-coated paper were analysed. The results were utilised in the development of the foam coating proces