Gas Barrier Improvement of PET Bottles by Diamond-Like Carbon Film

Abstract

The unique properties of diamond like carbon (DLC) film, including its chemical inertness and impermeability, make it possible for new applications in food and beverage. In this paper, I summarize and review the recent progress of gas barrier enhancement of polyethylene terephthalate (PET) bottles for beverage from the view point of the application of DLC coating. A unique technique of plasma CVD method has been developed to deposit DLC layer on the inside surface of PET bottles. The DLC-coated PET bottle exhibits extremely high gas barrier properties against oxygen, carbon dioxide and flavors compared to conventional bottles. For the practical use of PET bottles as a commodity, machines have been introduced for soft drink, wine, Japanese sake, edible oil, seasonings and others.