PLA Recycling Within PET Stream Debated

The debate whether bioplastics, specifically polylactic acid (PLA), can be recycled with mainstream PET continues to rage on. Released studies seem to contradict each other, with one indicating PLA does not contaminate the PET recycling stream and another indicating it does.

Bioplastics are used to create products typically made from petroleum-based products. They are biopolymers, derived from renewable biomass sources such as corn starch or vegetable oil. PLA is one form of bioplastic, produced from glucose.

The National Association for PET Container Resources (NAPCOR) recently announced its concern for potential contamination of the PET recycling stream associated with PLA bottles. The trade association for the PET plastic industry in the U.S. and Canada cited its concerns involving cost of separation, increased contamination, yield loss and impact on recycled PET (RPET) quality and processing.

Bioplastics often take the place of Polyethylene terephthalate (PET), but they aren’t compatible with this plastic resin when it comes to recycling. Bioplastics are often categorized as #7 plastic, which applies to anything that has a mixture of plastic resins. Photo: csrplus.co.uk

“We don’t doubt that PLA can be recycled,” said Tom Busard, NAPCOR Chairman, “but there are unquestionably some big issues yet to overcome.”

NAPCOR’s Technical Director, Mike Schedler, added, “The entire premise 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.”

On the other side of the debate are the manufacturers of PLA bioplastics. NatureWorks, LLC, a commercial manufacturer of PLA bioplastics, released the findings of a two-year bioplastics recycling study earlier this year, concluding that automated systems currently being used in the recycling industry are capable of sorting bioplastic bottles from petroleum-based bottles with an accuracy of nearly 100 percent.

“Demonstrating that natural plastic bottles can be brought seamlessly into the recycling stream through the use of automated sorting equipment available today is a major finding and another step toward greater sustainability,” said NatureWorks director of communications and public affairs, Steve Davies.

A mixed plastics recycling study, Domestic Mixed Plastics Packaging Waste Options, conducted by U.K. based Waste & Resources Action Programme (WRAP), also found that current NIR (near-infrared) recycling systems can effectively sort PLA from a mixed packaging stream.