Permeability to oxygen of cellophane laminates

Abstract

The effect of water vapour on the oxygen permeability of Cellophane laminates has been measured. A dimensionally stable coating can restrain the swelling of a water‐sensitive substrate to give a greater oxygen barrier than expected from the sum of the component barriers. This is discussed particularly for Saran on Cellophane. The permeability apparatus that has been designed depends on a commercial Pirani gauge. This allows accurate measurement and is very versatile.