A University of Wisconsin-Madison professor and a Green Bay company are working together to upscale a new recycling technique that could help keep flexible plastics out of landfills. The project is still in the early stages — with hopes to open a commercial demonstration facility in Green Bay by 2025 at the earliest. UW-Madison chemical and biological engineering professor George Huber is helping lead the project. He said a lot of plastics can’t be recycled using traditional methods because they’re composed of a mixture of several types of plastic. Those are typically used for “flexible packaging,” like the plastic wrapped around a string cheese stick or Ziploc bags.
Wisconsin has a robust packaging industry that employs 43,000 people — 25,000 of which are in flexible packaging — Huber said. That’s why researchers developed a plastic recycling process called “solvent-targeted recovery and precipitation,” or STRAP, he said. That research was supported by a grant from the U.S. Department of Energy. “What we do with STRAP is pick a solvent that will selectively dissolve one plastic. We then keep that hot while it’s dissolved, we separate the solvent from the undissolved plastic and then we cool it down,” Huber said. “The plastic precipitates and then you get the pure plastic back that you can use to reuse your original material or remake your original material.”
He said efforts to market STRAP have been aided by a partnership with Amcor, a global packaging company based in the Fox Cities. Amcor liked the STRAP technology and asked for samples of the material produced by the process that exceeded what researchers could produce in a lab, Huber said.That led to another partnership, this time with Michigan Technological University, to design a system that could produce larger volumes of material, Huber said. Through Michigan Tech, Huber came in contact with Green Bay-based Convergen Energy to expand STRAP.