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Chemistry, Materials & Packaging
Making a Hot Cup Recyclable:
The Innovation Behind the Scenes at WestRock

In 2019, WestRock’s answer to a recyclable hot cup was named a winner of the NextGen Cup challenge. Here, we go behind the scenes of developing this innovative barrier technology and hear what’s next for the holy grail of the easily recycled hot cup.

As the saying goes, necessity is the mother of all invention; and world-changing ideas start when there is an urgent need to address.

Each year, an estimated 16 billion disposable coffee cups are used globally, the vast majority of which are, contrary to what many people believe, nonrecyclable. As a packaging solutions provider to some of the world’s largest beverage distributers, as well as a recycling facility operator that manages about 8 million tons of product a year, WestRock is in a promising position to help innovate the way forward for the paper hot cup.

The problem with hot cups

When the average consumer goes to his, her or their local coffee shop to pick up the usual, many don’t realize that the sometimes seemingly eco-friendly cup can’t be thrown in the blue bin. This is because most single-use coffee cups are either plastic or paper lined, with plastic to insulate and prevent them from getting soggy and leaky when in use. This multi-layer makeup, although helpful for the drinking experience, requires a more advanced recycling process; and most communities in the United States and Canada aren't equipped to handle this. In addition, these cups do not degrade easily and therefore contribute to microplastic pollution.

That’s why WestRock decided a few years ago to invest in technology to develop a fully recyclable cup. The impact this could have would be massive.

The NextGen Cup Challenge

Initial efforts began several years ago with EnShield® — our existing paperboard technology that withstands oil and grease applications while being fully recyclable — to replace low-density polyethylene, a material commonly used to line paper cups. Our research team began thinking through ways to apply this innovative technology in the curved shape of a paper cup.

Then, in 2018, shortly after we’d already started down this innovation path, the NextGen Consortium announced the NextGen Cup Challenge. It was an open call to answer this question: “How might we design the next generation fiber cup to be recoverable on a global scale, while maintaining the performance standards we know and trust?”

This fueled our mission even more.

Although there were a few different ways of going about this, we ultimately focused our efforts on creating a recyclable coating. This is not an easy task. The coating needs to perform to existing standards and must be recyclable or repulpable — or returned to a state of pulp to be crafted into a new fiber product. We were looking for a chemical makeup that acted like the traditional plastic lining but didn’t negatively impact recyclability when applied to fiber products.

One particularly tricky challenge was that — to be stable — the coating had to seal to itself at a certain temperature during the cup-forming process, but not seal to itself in other parts of the production process or when sitting in hot trucks during transportation. As many packaging experts know, this is a fine line.

Another puzzle was considering all the stresses put on a cup during formation. The material must withstand folding and forming into a specific shape. We worked hard on the barrier chemistry to address all these technical challenges.

From over 480 teams from around the world that entered the NextGen Cup Challenge, WestRock was selected as one of 12 winners for our circular cup — a recyclable paperboard solution for hot or cold beverage cup applications. The solution meets all current specifications in the paper cup and foodservice industry while improving recoverability and enhancing the recycling process for 98 percent fiber yield. Currently, a limited number of paper mills accept poly-lined paper cups in North America. Our solution can be recycled more easily across a broad set of paper mills, helping ensure more high-quality fiber stays in circulation — which is good for the planet and the paper industry.

We had an amazing team on this work — including our barrier scientist, Jay Pang, as the technical team lead and senior researcher Natasha Melton on the innovation team; with Julie Gannon, our director of R&D, heading up the entire project. But many more individuals took part in this team effort, and I’m so thankful to everyone who participated in this challenge.

Bringing the cup to market

Once the technology was developed, our next focus was on bringing the cup to market. Consumer testing is a critical step in our innovation process; we do this through select pilots in partnership with our customers. The learnings from those tests inform subsequent, broader testing — allowing us to ultimately scale the most promising solutions.

We’ve been lucky to work with Tim Hortons as a brand partner for our pilot cup, which is expected to debut soon at select Vancouver restaurants.

Continuing barrier research

WestRock is excited to continue exploring recyclable barrier technologies for a myriad of other food containers. Ice cream pints, lined water cups and yogurt cups, among others, all require specialized technology developed for the item’s specific purpose. Each will have different formation processes and stressors, meaning that the paperboard and coating should be developed and supported slightly differently. We’re looking forward to addressing these challenges over the next few years, ultimately working toward the ability to offer paper alternatives to a wide variety of plastic cup needs.

In the meantime, I know I am not the only member of the team anticipating the moment when we see our prototype out “in the wild,” so to speak. As the project lead, Julie, mentioned recently, “To work on something for multiple years and then to see someone walk out of a store holding it... it will be a tremendous moment.”