Experimental study of dynamic wetting in reverse‐roll coating

Abstract

Abstract The movement of the dynamic wetting line in reverse‐roll coating was followed in a series of experiments that gave position, X D , angle, θ D and the critical metering roller speed, V M, cascade , for the onset of cascade. The data were correlated with operating conditions and compared with plunging‐tape air‐entrainment speeds, V* plunging . It was found that there was hydrodynamic assistance of wetting similar in form but smaller in magnitude to that reported in curtain coating. The correlated data for X D and θ D also provide boundary conditions, which can replace the assumptions usually made in the simulations of reverse‐roll coating flows.