Method of producing interiorly sterile packages possessing superior barrier properties

Abstract

A method of producing an interiorly sterile package possessing superior barrier properties, in which method a package is produced by blow moulding by means of gaseous blow moulding medium, whereafter the blow-moulded package is provided on its inner walls with a coating of a silicon compound by vacuum deposition, the coating acting as a barrier. According to one preferred embodiment of the method, the vacuum deposition is carried out in accordance with conventional chemical plasma deposition by means of a process gas which is identical with the gaseous blow moulding medium employed in the blow moulding operation. As gaseous blow moulding medium and process gas, respectively, use is made of a gas mixture containing oxygen gas and vaporized organic silicon compound, the mixing ratio between the gas components being controlled in such a manner that the coating which is formed in the chemical plasma deposition process consists of a silicon oxide of the general chemical formula SiO.sub.x, where x may vary from between 1,8 and 2,2. The chemical plasma deposition is discontinued when the produced coating has achieved a thickness of less than 2000 .ANG..

Dependencies are inferred from the claim text.