Sometimes innovations in the smallest areas can have a big impact. Plastic recycler Greenpath Enterprises hopes the technology it developed to create a closed-loop system for recycling bottle caps can be just such an advancement.
The Colton, Calif.-based company has launched a plastic flake sorting line it says can separate different types of caps into cleaner recycled resin streams that can be used to make new recycled-content bottle caps, a big step up over what happens now.
Traditionally the caps — a mix of polypropylene and polyethylene that is tough to separate — are sold into less valuable markets like plastic lumber or planting pots that can handle mixed grades of materials.
But Greenpath says it's worked with different equipment suppliers, including Germany's Tomra Recycling, to commercialize equipment that can create separate streams of PE and PP from the caps and sort them by color.
In a presentation recorded for the Sept. 18 Plastics News Caps + Closures online conference, Greenpath President Joe Castro said the company's closed-loop cap system allows brand owners to expand their use of recycled content packaging.
The Caps + Closures event is free to PN subscribers who register by Sept. 19.
"The exciting part of that is being able to now, with the advancements, being able to take this material and go towards cap-to-cap opportunities," Castro said.
Based on feedback from equipment suppliers and others in the market, Greenpath believes it has the first cap-to-cap system in North America.
Greenpath and Tomra jointly announced their work on developing some of the equipment in 2023, with a Tomra official saying at the time it was "the genesis of creating a sorting system for caps similar to what is more common today for the bottle."
Greenpath has commercialized the cap technology and is selling post-consumer resin. Castro said the company has modified different equipment to resolve technological hurdles.
Equally importantly, he said the market also needs a demand pull, in the form of voluntary commitments from brand owners or government incentives for recycled content.
"The demand is really what we've seen to be a key component, with the brands to be able to have the demand and motivation to use the recycled content into their packaging," he said. "The sustainability of this program, like many other challenging grades, still is highly dependent on the demand from manufacturers."
He said efforts to build supplies of recycled caps are important. That may cover bottle bills generating a cleaner material stream, education efforts reminding people to leave caps on when putting bottles into recycling bins, or design changes adding tethered caps to bottles.
He said in his presentation that he wasn't "pushing the policies," but noted that incentives to encourage recycled content are important to bolster recycling markets in down times.
"On the downward trends, it's extremely difficult for recycling companies to be able to profitably operate when/if virgin resin is too low and the cost to be able to recycle exceeds those numbers," Castro said. "We need to have programs, I think, to be able to help support, especially during those down turns, to be able to make sure that we're reusing our natural resources instead of throwing them away."
"Brand owner circularity commitments to use [post-consumer recycled resin] and laws supporting recycled content are very important to the recycling industry and this particular program," he said.
He said Greenpath, which has been recycling bottles caps into lower value, more forgiving markets for almost 15 years, saw opportunities in cap-to-cap recycling, both as technology got better and as it saw potential for more demand from brand owners.
"We had tried different equipment in the past, and it had made significant strides," he said. "It was the timing of the demand and the timing of the technology, and it was something we already had experience in. Because of our diversity and our background with light materials such as films, with different types of polyolefins, it really was a good fit."