Don’t mix recycled PLA and PET: plastics organization

A trade organization for the PET plastics industry in Canada and the U.S. is publicly questioning the mixing of bio-based polylactic acid (PLA) containers with recycled PET products.

Citing concerns over cost of separation, increased contamination and yield loss, and impact on recycled PET quality and processing, the National Association for PET Container Resources (NAPCOR) has refuted claims that PLA containers can be successfully mixed in to the existing stream of recycled PET containers.

“We don’t doubt that PLA can be recycled, but there are unquestionably some big issues yet to overcome,” said Tom Busard, chairman of the Sonoma, Calif.-based NAPCOR. “The current reality is that these issues transfer significant system costs and logistics burdens to the PET recyclers, impacting the viability and continued sustainability of their businesses.”

The PLA fraction will likely be mixed with other out-sorts from the PET stream, including PVC, PS and other resins, further complicating the marketing of the material, Busard also noted.

PLA and PET containers are not readily distinguishable by sight, Busard said, meaning that some type of autosort technology is necessary. Recent tests conducted by Primo Waters using PLA bottles manufactured by NatureWorks LLC, for example, indicate that near infrared sorting systems may be an effective means of sorting out 93 per cent of the PLA from the PET recycling stream.

“When all is said and done, the volumes of PLA that can be separated out at this time are relatively low and do not make up the critical mass required for a viable reclamation business model,” said Dennis Sabourin, executive director of NAPCOR. “The reality is that the PLA container becomes a contributor to PET bale yield loss which is already a big concern for PET reclaimers, as is the additional fraction of marketable PET which will invariably get sorted out along with the PLA. So not only is there an increased cost for sorting and a higher yield loss, but without any practical way to aggregate the sorted material, or markets for it, it’s destined for landfill.”