Study: To improve recycling, don’t crush containers
Recycling would be well served if Americans reconsidered a long-held approach to how they handle their plastics and other recyclables.
Crushing recyclables, including plastic bottles and containers, is an easy way to make more room in the recycling container. But that simple and time-tested practice actually can lead to a more difficult time for today’s material recycling facilities, says the new MRF Material Flow Study report commissioned by a handful of trade groups.
“If we keep the containers looking like containers, they are less likely to wind up in the paper stream. So the less flat they are the better, the more likely they are to get to their intended place,” said Resa Dimino, director of public policy at the National Association for PET Container Resources.
NAPCOR is one of five trade groups that commissioned the report by Resource Recycling Systems Inc. of Ann Arbor, Mich., in conjunction with Reclay StewardEdge Inc. and Moore Recycling Associates Inc.
Keeping containers looking like containers, and not crushing them, certainly is a change in the approach that recyclers historically have suggested. Curbside recycling started out with hand-held bins, where space has always been a premium.
But this is not 1985 anymore, or 1995, or even 2005.
While those bins certainly still are used in many communities around the country, they also are giving way to larger roll-out carts with much more room for citizen recyclers. That extra room, where available, means consumers do not have to be so worried about finding enough room for all of their recyclables in the container.
“I think that some of the most significant finds are that we can impact the success rate of our recycling efforts through some fairly simple and straightforward actions,” Dimino said.
Reeducating longtime recyclers to no longer crush their plastic bottles or steel cans, for that matter, might be challenging.
But Dimino said that times have changed for recycling over the years, and education about best practices for modern recycling equipment needs to be in place.
“A lot of our education and outreach is still focused on the MRFs of the early ‘90s, the dual stream MRFs. … For efficiency sake, you wanted to crush everything and get that through. But in today’s facilities, it doesn’t work that way anymore,” she said.
Today’s MRFs are designed to best handle and separate materials when they are in their original shape, the report finds.
“The study found that three-dimensional objects [packages in their original form] vs. two-dimensional [flattened/crushed objects] have a higher likelihood of making it through the system to the appropriate container lines and bales,” said Jim Frey, CEO of Resource Recycling Systems, in a statement.
“This is not only a helpful finding but an actionable one which illustrates that even everyday actions in the home can help boost recovery,” he said.
That’s because the flattened containers have more of a chance of being mistaken for paper by sorting equipment.
The compaction issue is not limited to just the home.
Waste and recycling collection companies rely on compaction to create efficiencies on routes that can easily have more than a thousand customer stops during a single shift.
Dimino said that recycling routes, unlike garbage routes, do not typically run up against truck capacity issues, however.
“We’ve learned over the years that recycling trucks are rarely filled to capacity. They run out of time before they run out of space,” she said.
“I think for the carting community, the waste handling community, it’s worth a look at how much do we really need to compact in the collection truck and what’s the least compaction you can get away with and still run an efficient route,” she said.
And once the material does end up at the MRF, Domino said, there are compaction opportunities there as well. Recyclables are typically emptied onto what is called a tipping floor at the front of the recycling line. That’s where front-end loaders are used to feed the material onto the recycling lines.
But those multi-ton loaders also can end up running over the mixed recycling stream as well during the process.
“Once it gets to the MRF, there’s a lot of things that get run over by a front-end loader as the machine is pushing material around, so often just being more careful and thoughtful about not compacting the materials through various MRF operating techniques,” she said.
The report also suggests that form, material type and rigidity “have a significant effect on a product’s ‘sortability’ in the MRF.”
“Lightweighting of plastics can decrease recovery in a single-stream MRF due to loss to the paper streams,” the report states.
Lighter weight bottles these days are simply easier to crush compared to their counterparts from years ago, Dimino said.
Adding equipment, and properly maintaining disc screens that are designed to separate paper from heavier recyclables, also can help separate two-dimensional recyclables, think paper, from three-dimensional materials, think containers.
“MRFs who maintain those screens where that separation happens, maintains them more actively, have better outcomes as well,” Dimino said. “You can start to see how some of the financial investment in things like maintenance might pay off in terms of additional material value.”
Disc screens are designed to allow paper to ride along on top and separate from other recyclables that fall through. But when these disc screens become clogged, they also end up routing more than just paper along to the fiber sorting portion of the MRF.
The increased use of plastic bags and other films have been a particular nemesis to MRFs in recent years as they become entangled in these screens and block the containers and bottles and such from falling through to their own sorting line.
A total of five MRFs in the United States were selected to examine both single-stream recycling, where all recyclables are placed in the same bin by customers, and dual-stream recycling, where the paper fraction is kept separate. The different MRFs also represented different throughputs and recycling material options.
Aside from NAPCOR, other groups behind the report are the Carton Council, the American Chemistry Council, the Association of Postconsumer Plastic Recyclers and the Foodservice Packaging Institute.
Having all of those groups come together to examine the issue, Dimino said, “is a very good sign for our industry moving forward.”
“I think it’s a great indicator of the kind of collaboration that’s happening across industry groups these days,” she said.
Municipalities can help by regularly communicating with their MRFs to understand the behavior of materials while they are being sorted, the report states. Municipalities also must continually educate their residents regarding contamination gas the list of acceptable materials continues to grow.
Municipalities also can plan a role in educating consumers to not crush their recyclables to improve the likelihood of their recovery once they hit the MRF, the report states.