The practical advantages and disadvantages of plastic beverage bottles are discussed with particular reference to PET, which is superior to most of the other plastics used (or proposed to be used) for bottle production in many respects, but has the disadvantage (especially in relation to beverages susceptible to oxidative deterioration, such as beer) of being relatively permeable to gases. The development of potential solutions to that problem (including laminated bottles having a layer of a gas barrier material, such as nylon, sandwiched between layers of PET, the incorporation of oxygen scavenging substances, as layers or additives, into PET bottles and the use of plasma coating technology to apply a thin layer of either a carbon based or a silicon based impervious material to the interior surfaces of PET bottles) is briefly described and the respective advantages and disadvantages of the different available technologies are compared. From the viewpoints of both product shelf life and ease of recycling, the author regards plasma coating with silicon dioxide as the best gas barrier treatment for PET bottles available at the time of writing.
