Influence of Surface Tension and Surface Shear on Final Coat Thickness in Jet-Stripped Continuous Coating of Sheet Materials

摘要

There are many situations in which a liquid film needs to be wiped off a solid surface, and one of the most common technological stripping mechanisms used for that purpose is a high-speed fluid jet. The industrial importance of this method of film wiping has prompted scientific studies of the process, but so far, these have accounted only for the pressure exerted by the jet on the film. This document gives consideration also to surface tension and tangential stresses, and analyzes under what circumstances they have an important influence on what can be achieved stripping a film with a jet. The equations governing the process in those circumstances are established and analyzed. Numerical results, moreover, are obtained which quantify the extent to which surface tension reduces the wiping effect of the jet. (Author)