ABSTRACT
An analytical model is presented that describes the water vapour permeability of a perforated foil in dependence of pinhole dimension, degree of perforation and water vapour permeability of the contacting media. A comparison of analytical solutions with numerical results indicates a good agreement when the degree of perforation is not too large. The differences are smaller than 15% in case the ratio of pinhole surface area to total area is less than 5%. Experimental data obtained by others are generally well described by the model, but differences are seen for foils attached to a solid material.
