engleski

Effect of temperature and mechanical stress on barrier properties of polymeric films used for food packaging

The permeance of carbon dioxide, oxygen, nitrogen and air through commercial polymers based on polyethylene (PE), biaxially oriented polypropylene (BOPP) and polyamide (PA) used for food packaging is reported. The influence of temperature (from 10 to 60oC) and crease stress cycles (30, 50, 70 and 110) on gas permeance was also analysed. Generally, the highest changes in gas permeance changes with increased stress cycles are observed with films having a metallized layer in the structure, namely BOPPcoex/BOPPcoex.met and, to a lesser extent, BOPPcoex.met/PE laminate. The lowest crease stress influence on barrier properties was obtained for PE film. In this case, the highest activation energy for the permeability coefficient (P) is obtained. Normal progressions of activation energies for P are: N2=Air CO2 O2.

Crease strains; Gas permeance; Laminates; Monofilms

nije evidentirano