Recycling more PP requires more focus in design, collection, sorting

National Harbor, Md. — Polypropylene is just as big in packaging as PET but it is recycled at a fraction of PET. Only 8 percent of 1.2 million tons of post-consumer PP is recycled.

But getting this material into a circular economy will support companies aiming for ways to meet extended producer responsibility (EPR) requirements while also meeting recycling targets.

Panelists at the Plastics Recycling Conference in National Harbor discussed the growing popularity of PP and how optimizing collection starts with design and a focus on sorting.

For consumers, polypropylene does not get recycled much. Edward Kosior, president at Nextloop Americas, notes that the shapes of PP containers are usually pots, tubs, trays and only a few bottles. Bottles are what an average consumer recognizes as recyclable, which means they overlook the variety of other forms in which the material is recyclable.

A lot of companies are choosing PP due to performance characteristic benefits that come along with the material and being able to process well, the clarity, heat resistance, stiffness and impact resistance.

Jeff Snyder, senior vice president of recycling at Rumpke Waste and Recycling, said the Cincinnati-based company and others must continue to inform end users on what materials and items are recyclable.

Other panelists agreed with Snyder. Neil Darin, senior director of resiliency and holistic packaging at consulting group TMS, encourages companies that are making more developments and investing in new techniques to bring the consumers along for the journey and keep them informed.

"We've seen actually consumers getting more engaged in recycling, only to see that rescind a bit," Darin said. "We've got opportunities to invest in all of the great new technologies and infrastructure, We've got to bring the consumer along in that journey and make them care and want to recycle."

With PP gaining popularity in the recent years, the industry still sees itself trying to catch up. Rumpke, a waste and recycling company, was fortunate enough to have the space to jump on the trend faster than others, Snyder said. The company was quickly able to get the equipment that was needed to sort the material.

Snyder saw that a lot of cups ended up being under collected and made more of a point for Rumpke to start collecting cups from end users.

"It was kind of a no-brainer to keep this thing evolving as we moved forward," Snyder said. "And the latest of being able to put a camera imaging on top of NIR, just takes sorting to another level."

A big breakthrough in the industry has been in sorting, being able to separate food from non-food grade PP using AI and using decontamination technologies. AI has made advancements within the sorting industry has made collection easier and optimized how much material recyclers are able to get.

Compared with the development of recycled PET and high density polyethylene, PP has grown in popularity quickly over the past couple years due to the end markets that really opened up. The sort ability for the material is high and food grade of the material is over 75 percent of recycled polypropylene.

The panelists said brands are coming together more and providing money towards material recovery facilities, or MRFs.

Kosior said companies must design for recycling, stating that many products are made to be used once. With the more demand of polypropylene, there must be a mindfulness within the industry of the stabilization and reprocessing of those materials.

To design for a more circular economy, company can be using stereotypical attributes in products to lead to AI systems being able to identify them.

"If you use a totally radical design and say it's food grade PP, the machine won't recognize it because it doesn't have those attributes," Kosior said. "Businesses making packaging have to stick to broad design rules to make sure that the AI can pick it up."

If companies want to use different designs, there must be more AI system learning so that those items are learned and recycled properly.

Design advancements don't just stop at packaging. Panelists said they also must design MRFs for more success. By group items into broad categories, upping AI sorting

Another new development is how 2D and 3D objects are sorted in a MRF. By using more optical scanners and ballistic optic separators, small format PP material is being recycled more frequently.

"We're starting to get those smaller formats," Snyder said. "They would have traditionally either went out as trash or ended up in the glass stream. ... There are ways of designing your facility to be able to capture at a very high rate."

For the future of the industry, Kosior sees a new phase of companies being more careful of material selection, stabilization and design packaging so that MRFs pick things up as food packaging.