PLA does not endanger PET recycling

Biobased plastics, such as PLA, and an increase in recycling, are key to achieve a circular economy, and decouple from fossil feedstock. To this end, PLA should be integrated in waste management systems, without disturbing existing recycling streams.

Due to its functional and sustainability properties, PLA is mainly used in packaging applications. To answer concerns on the impact of PLA on the PET recycling stream, the Dutch University of Wageningen conducted a study in collaboration with TotalEnergies Corbion. The results were published this January, under the title: “Effect of poly lactic acid trays on the optical and thermal properties of recycled poly (ethylene terephthalate)” .

The study concludes that considering current industrial methods for sorting and recycling, PLA has little to no influence on recycled PET (rPET). The current concentration of PLA in the Dutch recycled PET was estimated to be between 0% and 0.019%. Even with an increase of PLA consumption, the near-infrared sorting technology allows to keep this concentration below 1%. PLA food trays were added to PET bottles in concentrations from 0.1 up to 1%. At 1% and bellow, the influence of PLA on optical and thermal properties of PET was negligible. Conversely, 0.1% of PVC already showed a negative impact on recycled PET.

The authors Eggo van Velzen, Sharon Chu, Karin Molenveld and Vladislav Jašo conclude that

“In case the sorting and recycling facilities maintain their current careful operation, no negative impact of PLA on PET recycling can be foreseen, and further integration of biobased plastics in the plastic waste management system can be pursued.”