Silicon Oxide Barrier Coatings Deposited on Polymer Materials for Applications in Food Packaging Industry

Deposition of SiO(x) layers by low-pressure microwave plasmas is an excellent means to add missing barrier functionalities to cheap and material-saving homo-polymeric materials that will increasingly replace expensive multi-layer polymer food packaging. SiO(x) coatings were deposited in an ECR plasma process on polyethyleneterephthalate (PET) foils using two different precursors, HMDSO and HMDSN. O(2) transition rates of less than 1 cm(3) (m(-2).24 h(-1).bar(-1)) were obtained for the best performing SiO(x) coatings deposited from O(2)/HMDSN gas mixtures. First ECR plasma deposition tests on polypropylene (PP) trays show the high barrier potential of SiO(x) coatings even on three-dimensional polymer food packaging.