Introduction to packaging
Permeability measurements to control the preservation of packaged foods

Packaging is a dense polymeric membrane, single or multi-layered, single or multi-material, which separates two media:

• the external environment ;

• internal environment.

This barrier maintains the food in conditions that "stabilize" or, at the very least, slow down its aging process. Figure 1 shows incoming and outgoing flows for a two-component package (hollow body and its closure system). The two media referred to as "upstream" and "downstream" are defined in the direction of transfer, or the direction of the arrow.