Novel thin functional coatings for paper by foam coating

Conventional coating methods are currently being challenged by newly developed technologies that can result in products with interesting properties and competitive prices. Versatile foam coating is one such promising technology. Foam coating is carried out using different foam application methods, and the viscoelastic nature of the foam allows the use of a large variety of materials. Paper was coated with nanomaterials on a pilot scale using a method based on slot die application combined with foam destruction by absorption and infrared drying. A thin layer of titanium dioxide/zinc oxide (TiO2/ZnO) functionalized cellulose nanofibrils (CNF) creates antimicrobial properties in the paper, and a thin layer of CNF-TiO2 alone has substantial ability to oxidize nitric oxide (NO) and nitrogen oxides (NOx). These results illustrate methods that can be used to create novel functional properties for different end-use applications. Thin functional layers could bring added value to current products and also create opportunities to introduce novel products for several industrial areas using web-type manufacturing processes.