Recycling PLA with PET 'Jeopardizes the System,' NAPCOR States

Because PLA and PET containers are not readily distinguishable by sight, some type of autosort technology is necessary, NAPCOR notes.

28 Jul 2009 The National Association for PET Container Resources (NAPCOR) has refuted the premise that polylactic acid (PLA) containers can be successfully mixed into the existing stream of recycled PET (RPET) containers, citing concerns over cost of separation; increased contamination and yield loss; and impact on RPET quality and processing.

“We don’t doubt that PLA can be recycled,” says NAPCOR chairman Tom Busard. “But there are unquestionably some big issues yet to overcome. 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 business. NAPCOR has spent over 20 years helping to build a successful domestic PET recycling infrastructure, and this solution not only jeopardizes the PET system, but is not an effective solution for PLA.”

NAPCOR technical director Mike Schedler adds, “The entire promise that you can simply add PLA containers into the PET recycling stream, successfully sort them out, and eventually find markets for the material is like advocating that mixed ceramic materials can be thrown right in with the recyclable glass stream to be sorted out, and that eventually there will be enough of this mixed material that someone will want to buy it. It’s really no different from this and just isn’t a viable solution from anyone’s point of view.”

Schedler adds that the PLA fraction will likely be mixed with other outsorts from the PET stream, including polyvinyl chloride, polystyrene, and other resins, further complicating the marketing of the material.

Because PLA and PET containers are not readily distinguishable by sight, some type of autosort technology is necessary, NAPCOR notes. Recent tests conducted by Primo Waters using NatureWorks PLA bottles indicate that near infrared (NIR) sorting systems may be an effective means of sorting out 93% of the PLA from the PET recycling stream. NIR systems are not currently used by all recyclers and require a significant investment, typically $200,000 or more. Those who invest in the systems expect them to be able to sort at 95% or better. Other sorting systems were not part of the recent tests, nor were ways to address quality issues, such as PLA getting stuck in the dryers during the PET reclamation process.

“And when all is said and done, the volumes of PET that can be separated at this time are relatively low and do not make up the critical mass required for a viable reclamation business model,” says NAPCOR executive director Dennis Sabourin. “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 higher yield loss, but without any practical way to aggregate the sorted material or markets for it, it’s destined for landfill.”

Sabourin also points out that the thousands of curbside recycling programs rely to varying degrees on the market value for materials. Diluting this value runs contrary to the current need to bolster these programs and related infrastructure—particularly in weaker economic times when some communities are struggling to maintain them. “NAPCOR has no wish to impede the recycling of additional resins, including PLA, but we can’t sanction putting successful programs in jeopardy through the premature inclusion of other resins into the PET system,” he adds.

NAPCOR advocates extreme caution moving forward: Today’s domestic PET recycling system can’t successfully absorb PLA containers, nor does this scenario offer a sustainable model for PLA. NAPCOR calls on brand owners and decision makers to fully consider the impacts and the realities of the current situation when they make the packaging decisions that address their product requirements and sustainability goals.