ABSTRACT
Permeability is a process that involves adsorption (dissolu-
tion) of a low-molecular-weight gas (e.g., oxygen or car-
bon dioxide) or vapor (e.g., water vapor or food aroma)
onto one side of a plastic polymer (e.g., polyethylene) film,
diffusion through the film, and then desorption (evapora-
tion) from the other side of the film. The net transfer of the
gas or vapor (permeant) is from the film side where it is at
higher partial pressure to the film side where it is at lower
partial pressure.
