Rheological Effects on Forward Deformable Roll Coating
The role of fluid rheology in forward deformable roll coating was experimentally studied using coating liquids exhibiting a wide range of rheological properties. The emphasis was put on the understanding of the film splitting mechanism and the ejection of droplets at the exit of the coating nip. The flow visualization downstream the coating nip revealed the presence of a meniscus extending from the nip to form a series of filaments, which in some cases broke up ejecting misting droplets. A strong effect of the liquid rheology was observed on the pressure distribution measurements carried out by a dynamic pressure sensor mounted on the rigid roll. It was shown that viscoelastic liquids develop high pressures into the nip and very low pressures at the exit. Elasticity was shown to retard misting.
- Journal of chemical engineering of Japan
Journal of chemical engineering of Japan 41(4), 217-226, 2008-04-01
The Society of Chemical Engineers, Japan