A coalition of recycling associations and nonprofit recyclers continues to pressure NatureWorks LLC to place a moratorium on the use of corn-based polylactide resin to make plastic bottles, even as the company continues to have discussions with the recyclers.
NatureWorks said it has not made a decision on the moratorium request - a slightly different stance than its initial reaction, which was that it intended to pursue bottle applications and that the marketplace should decide whether it wanted PLA bottles.
Now advocates of the moratorium are encouraging the public to get involved. The Web site of the Plastic Redesign Project (plastic redesignproject.org), a multistate coalition of public recycling officials, has added information on the problems PLA presents for sorting and recycling, and questions the likelihood of whether PLA products will be composted at the end of their life cycle. The site also gives visitors a chance to get involved in a letter-writing campaign to NatureWorks.
Contamination, biodegradability and compostability are the main points of disagreement.
NatureWorks points out that optical infrared sorting equipment can separate PLA and PET bottles with a 97.5 percent accuracy rate. But the coalition said that still would leave enough PLA in the recycling stream to cause contamination problems.
``NatureWorks' own tests indicate just one-tenth of 1 percent of PLA remaining in PET bales will contaminate the load,'' said the Web site.
In addition, the cost of sorting equipment is between $100,000 and $200,000 - an investment recyclers said is difficult to justify for the limited amount of PLA now being produced.
``If you are recycling less than 20 million pounds, the fixed costs are too high,'' said Dave Cornell, technical director for the Association of Postconsumer Plastic Recyclers in Washington.
``It is not a terribly good return on your money.''
Compostability is another issue that needs to be resolved. The Web site notes that while PLA theoretically can be composted, ``there are only a limited number of industrial-scale compost facilities'' and that ``unfavorable economics place near-insurmountable roadblocks in front of PLA composting.''
Peter Anderson, staff director of the Madison, Wis.-based Plastic Redesign Project, said it does not make sense to jeopardize the PET recycling stream, which pays recyclers 20-25 cents per pound for the 1 billion pounds of PET resin recycled annually.
``With what we know, [PLA] is neither compostable nor recyclable at present, and it will degrade significantly the successful PET recycling program we have today,'' said Anderson, who also is executive director of the Center for a Competitive Waste Industry, also in Madison.
NatureWorks spokeswoman Mary Rosenthal agreed that ``there are a limited number'' of composting facilities that accept PLA and that ``there are difficulties today.''
``But we expect to get over these hurdles as we go down the road. We are trying to create that road map for the long-term end-of-life vision'' for PLA.
She said Minnetonka, Minn.-based NatureWorks is continuing its dialogue with the recycling coalition ``to identify the hurdles ... in recycling PLA-based bottles. It is a major company focus to solve this problem and create a pathway to success'' for PLA.
Regarding the Plastic Redesign Project's Web site, Rosenthal said: ``The coalition has done an excellent job of outlining the problems and has made some valid points.
``The identification [and] sorting issue is a very valid point. We are listening well to understand their needs. We need to understand all of their economics and are working through what that model needs to be for PLA. It is very important for us to connect with key stakeholders like this coalition.''
Still, the recycling challenge will remain a daunting one.
``It is not causing great consternation at this point, but it could become a problem,'' said APR's Cornell. ``The trick is to turn the potential problem into an opportunity. NatureWorks does understand their product stewardship responsibility, but they are facing a tough task.''
Coincidentally, the stepped-up effort by the coalition comes at the same time that other reports indicate PLA trays entering the recycling stream are causing problems for PET recyclers.
``We are finding that there is a big increase in PLA trays in the recycling stream and that they are problematic because they degrade at low temperatures,'' said a recycler who is not a member of the coalition. ``It is an issue and I am concerned that it will become a bigger issue before it gets resolved.''
Another recycler echoed the same thought. ``PLA is a low-melting amorphous material and causes problems ... because PET recycling processes tend to operate at higher temperatures. So if you get even 1 percent of PLA in the dryers used in PET recycling, it makes a sticky mess.''