Film casting is used for viscous coatings. Coating layers approximately
100 microns up to even 4 millimeters can be applied using a gap between a web and metering rod. Currently cast coatings are carried out
using a manual feed but the facility will be developed to include a feeding pump designed for viscous dispersions in order to produce thin coatings continuously on the webs.
Cast coating can be used to, e.g., produce thin films or thin coating layers from cellulose nanofibrils and other bio-based nanoparticles for high-performance applications, such as membranes or filters with special functionalities, e.g. metal ion capturing, thermo-responsive, or anti-fouling performance. The challenges are related to cost efficient drying strategies of these biomaterials
due to their high initial water content. The thinnest applied coating layers are in the size-range of
1-2 Ám and self- standing films up to about
15 Ám or above.
Cast coating applicator. Smooth films made from translucent and transparent cellulose nanofibrils (CNFs).