Starbucks and WestRock completed a pilot to recycle fiber from 25 million coffee cups for new cups.

Recycled paper company Sustana invested in pulping equipment to remove polyethylene liners from the cups and save the fiber, which was mixed into paperboard at WestRock’s mill in Evadale, Texas. Large rolls went to Seda packaging company for printing, cutting and forming.

Recycling operations typically do not have the resources to pull cups from the waste stream or the equipment to separate plastic liners, meaning tens of billions of cups go to landfills every year in the U.S., according to industry estimates.

“We’ve been working together for many years to advance the potential to recycle cups, and it’s so great to demonstrate its viability,” WestRock Public Policy Director Rhea Hale says in a video explaining the venture.

The project demonstrates the use of closed-loop circular economy.

“If we can pull off this execution seamlessly and we can repeat it each and every time, we’re solving this problem of landfill and pollution and all this waste that’s really degrading the environment,” Rebecca Zimmer, Starbucks global director of environment, says in the video.