A Comparison of the Sealing, Forming and Moisture Vapour Transmission Properties of Polylactic Acid (PLA), Polyethene (PE) and Polyethylene Terephthalate (PET) Coated Boards for Packaging Applications

Due to the waste problems associated with plastic packaging and the desire to reduce fossil fuel-based packaging, many retailers and brand owners have set ambitious targets to reduce the use of non-renewable polymers. One aspect of this trend has been an increase in the use of bio-coated boards as an alternative to boards coated with traditional petroleum-based polymers such as PE and PET. This paper identifies the polymers used in a number of commercial boards coated with conventional or biopolymers and compares their performance in terms of the moisture vapour barrier, sealing behaviour, and their ability to be folded without cracking. It was found that PLA was the biopolymer used to coat the two bioboards studied, and while it compares favourably to PE and PET coated boards in terms of heat sealing capabilities, it has potential conversion issues due to it’s brittleness and has inferior moisture barrier properties compared to traditional petroleum-based coated boards.