InterviewPolylactic acid advantages outweigh risks - NatureWorks

05 August 2009 18:03  [Source: ICIS news]

By Landon Feller

HOUSTON (ICIS news)--US biopolymer producer NatureWorks said Wednesday that recent criticism on the viability of sorting polylactic acid (PLA) resins in recycling processes, particularly for polyethylene terephthalate (PET) players, resulted from a misinterpretation of the company's research.

NatureWorks’ public affairs director Steve Davies said a 24 July press release from the National Association for PET Container Resources (NAPCOR) misconstrued parts of the company’s analysis of PLA sorting in plastics recycling.

In addition to the mistaken assertion that NatureWorks wants PLA recycled with other plastics, the NAPCOR statement confused a 93% PLA removal efficiency as a 7% yield loss in bales of recycled PET, Davies said.

Because PLA has gained traction in various packaging markets, NatureWorks teamed with US bottler Primo Water to research whether PLA could be effectively sorted from the post-consumer recycled (PCR) plastic stream, and to determine what levels of PLA contamination were acceptable.

“These are not simple tests or results, some of the statistics can be easily misconstrued,” Davies told ICISnews.

In the end, Davies said NatureWorks agrees with NAPCOR on most points, particularly that sustainable PLA sorting and reclamation remains a goal, and that recycling infrastructures are currently incapable of absorbing all PLA containers.

Aside from engineering the first new packaging polymer in three decades, Davies noted that NatureWorks is the only producer to have actively sought end-of-life solutions from the start.

The company said it wants to answer questions that have been raised on managing the presence of PLA in a recycling stream consisting of mostly oil-based polymers, but depends on groups like NAPCOR and the Association of Postconsumer Plastics Recyclers (APR) to provide a platform to share its findings.

Only two of seven plastics are actively sought for recycling, and roughly 75% of all virgin PET bottles currently end up in a landfill, Davies said.

As the current system is clearly not without flaws, Davies said having a resin producer so actively involved in the process should only speed up the evolution of a more sustainable recycling industry.

Ultimately, there is a place for both traditional polymer recycling and plant-based polymer reclamation that will enhance the economics of both systems, he said.

Davies laid out the company’s vision for a reclamation process that would involve the PLA producer working with recyclers to create a system by which NatureWorks would buy back reclaimed PLA bales, which would then be fully depolymerised back into the raw material lactic acid.

As for the difficulties NAPCOR cited in separating PLA using existing sorting equipment, Davies said a simple, inert additive can be easily included with the PLA resin to make it fluoresce under a blacklight, at negligible additional cost to the recycler.

Compared with the buy-back rates of PET producers who are limited in the amount of recycled content they can blend with virgin resin, the economics of NatureWorks’ model for PLA reclamation only get more efficient as volumes increase, he said.

“This isn’t a battle against the existing market. We think the right questions are being raised and we want to answer them,” Davies said, adding that the burgeoning PLA industry has emerged to meet pre-existing market demand for non-petroleum based polymers.

Going forward, NatureWorks said it will seek to organise a case study in California to explore a system in which the PLA life cycle is properly managed and does not harm the PCR stream or add prohibitive cost to recyclers.

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By: Landon Feller
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