Development of plasma polymerised SiO_x barriers on polymer films for food packaging applications

Expensive polymer food packaging consisting of multilayer systems of different polymers will be increasingly replaced by cheap homopolymeric materials. Low-pressure plasma deposition of SiO_x layers provides a promising alternative to achieve barrier properties on homopolymeric materials directly comparable to those of multilayer polymer packaging. Oxygen and HMDSO were applied for depositing SiO_x layers on poly(propylene) (PP) and polyethyleneterephthalate (PET) foil samples by using two different low-pressure microwave plasma sources. Significant improvements of the barrier properties were achieved in the first experiments, e.g. the oxygen permeability could be reduced by a factor of 65.