Double-coating external layer also claims to work on polypropylene

The South African Council for Scientific and Industrial Research (CSIR) has patented a coating technology to improve the barrier properties of PET bottles. The Oxyplete technology – which is based on a double-layered external coating system – can be successfully applied to PET as well as polypropylene packaging. It is expected to extend the shelf life of the more oxygen-sensitive beverage products such as juices, teas and flavoured water.

CSIR noted that while polymers such as PET have the best gas barrier properties of all standard polymers, and is a popular packaging format for soft drinks, it has insufficient barrier properties for many demanding food and beverage applications. CSIR claims that Oxyplete performs better than any other passive barriers currently available and has a 30-times better gas barrier than normal PET. It is also suitable for demanding applications such as hot or cold filling for beer and baby food packaging.