Conversion Of Aluminium Oxide Coated Films For Food Packaging Applications—From A Single Layer Material To A Complete Pouch

Transparent barrier films based on vacuum deposited aluminium oxide (AlOₓ) layers are continuing to create large interest in the market with regards to their use as food and healthcare packaging materials. Nevertheless, their post-metalliser conversion to the final packaging material still presents challenges to current AlOₓ producers and the wider converting industry. In this work, AlOₓ coated polyethylene terephthalate (PET) films have been converted in long duration industrial-scale trials via topcoating, printing, lamination and finally pouch making. Throughout this process, each conversion step has been investigated for its effects on the barrier performance. It was found that the printing processes, especially, induce significant damage to the ceramic barrier layer. However, by the use of a protective topcoat prior to any conversion step, the barrier properties of the AlOₓ coated film were preserved, or could even be significantly enhanced, depending on the topcoat material. Furthermore, for a barrier topcoat, remarkable stretch- and flex-durability properties were achieved in the final laminate.