Unsteady- and steady-state gas permeation through active packaging walls

Steady‐ and unsteady‐state gas permeation rates through packaging walls containing active (scavenger) materials are determined as functions of the system's physical parameters and the scavenger load. With the simplifying assumptions of constant scavenger concentration and first‐order reaction kinetics, steady‐state analysis shows that there is a minimum quantity of scavenger that must be added to the packaging wall if any reduction of gas permeation is to be achieved. Unsteady‐state studies have established the dependence of the time needed to reach stationary behaviour on the system's physical parameters. Copyright © 2007 John Wiley & Sons, Ltd.