Wave of PLA applications puts strain on limited supplies

A wave of first-time applications for polylactide (PLA) in peelable and die-cut lidding, laminated boards, pouch materials and sandwich packs is set to delight consumers, while also putting supply of the biopolymer under severe strain.

Films converter Rockwell Solutions says that tests are underway on a number of applications for food. These include a fully compostable pack combining an ovenable tray, derived from sugar cane material, with Rockwell's PLA Biopeel lidding film. This is available in two different peel strengths, says md Zain Okhai. The combination is apparently currently undergoing testing for use inside the EU.

Amcor Flexibles, which markets a microperforated version of the peelable film for fresh produce, is expected to announce the first application for a pre-packed salad.

Manufacturer shelf-life tests are being undertaken for folding box board laminated with the PLA film. According to Okhai, this gives a moisture-resistant pack which is not only fully compostable but also "100% heat sealable". For heat seal requirements, Rockwell applies a biodegradable coating to the PLA. "Yoghurt producers are also looking at using this type of laminate in place of the biopolymer on its own," he reports.

Rockwell is among those working with Marks & Spencer on PLA packaging. Okhai says: "This retailer has clearly said that it expects use of these materials to increase sales. People are using environmentally responsible packaging as a marketing tool."

But converters are still dependent on a limited global supply of PLA. Rockwell sources all its material from NatureWorks in the US, which is not expected to resolve a serious production bottleneck until 2008. "When a supermarket makes contact with us, they'll seek confirmation of an allocation of PLA from NatureWorks," says Okhai. The US company will then reciprocate by seeking undertakings on volume requirements.

One of the applications that has already received advance allocations from NatureWorks is an all-compostable sandwich pack which uses a thermoformed PLA "wedge", Rockwell's peelable film and a label. Other "firsts" in the pipeline include a self-venting PLA pouch for microwave steaming.