Free coating of a Newtonian liquid onto a vertical surface

The entrainment of Newtonian liquid films onto a vertical surface which is continuously withdrawn from a bath of the liquid is considered. A new theoretical treatment is presented which is significantly different from previous theoreis and which predicts accurately the relationship between the dimensionless thickness parameter, T₀, and the Capillary Number, Ca, up to a value of Ca of 2. Experimental results have been obtained using a capacitance technique for film thickness measurement for a variety of Newtonian fluids with viscosities ranging from 0·006 to 2·06 N. sec m^?2.