The Wisconsin Alumni Research Foundation is seeking partners interested in supporting pilot operations and commercial development of STRAP technology, which uses targeted solvent washes to separate multilayer plastic films or mixed plastic waste into individual polymers, enabling both recycling and upcycling of materials previously considered unrecyclable.
From preserving food to protecting medical supplies, multilayer plastic packaging plays a vital role in modern life. By combining polymers, manufacturers create films with specialized traits like heat resistance and moisture control. Yet, despite their usefulness, these plastics pose a major environmental challenge.
Each year, the world produces roughly 100 million tons of multilayer thermoplastics, some with up to 12 layers. A staggering 40% of this is discarded during manufacturing, and without a way to separate the layers, nearly all of it is destined for landfills or incineration.
UW-Madison researchers have developed a method for reclaiming the polymers in these materials using solvents that selectively dissolve and separate each plastic type, a technique known as Solvent-Targeted Recovery and Precipitation, or STRAP. By using targeted solvent washes, STRAP breaks down complex plastic films or mixed plastic waste into individual components, known as resins. These resins can be reused to create the same products they came from or even upcycled into higher-quality materials.
Unlike other solvent-based recycling methods, STRAP includes a computational system that suggests appropriate solvents and temperatures for recovery based on the target polymer and the other polymer components.
- Enables recycling of previously unrecyclable multilayer plastics and mixed plastic waste
- Allows multilayer plastic manufacturers to recover plastic waste produced during the production and packaging processes
- Capable of processing a wide range of multilayer materials, including clear rigid films used in food containers, printed packaging films, mixed plastic waste, disposable face masks and plastics collected with municipal solid waste
- Produces high-quality material that is nearly indistinguishable from virgin plastic
- Economically competitive against virgin plastic production while reducing greenhouse gas emissions by up to 70%
- Scalable using mostly standard equipment
The process has already been tested on post-industrial waste samples provided by more than 30 industrial partners through the U.S. Department of Energy-funded Chemical Upcycling of Waste Plastics (CUWP) center. A pilot plant at Michigan Technological University is under construction and slated to begin operation in the coming months, producing 25 kilograms of recycled plastic per hour. Here, the technology will be tested and optimized for industrial-scale use.
- Sánchez-Rivera et al. A solvent-targeted recovery and precipitation scheme for the recycling of up to ten polymers from post-industrial mixed plastic waste. Waste Manag. 2025 Feb 15;194:290-297. doi: 10.1016/j.wasman.2025.01.022. Epub 2025 Jan 21.
- Xu et al. Extraction of Pure Plastic Resins From PCR plastic waste by solvent-targeted recovery and precipitation (STRAP). Journal of Advanced Manufacturing and Processing. 7, no. 3 (2025): e70023. https://doi.org/10.1002/amp2.70023
- Walker et al. Recycling of multilayer plastic packaging materials by solvent-targeted recovery and precipitation. Sci. Adv. 6, eaba7599 (2020). doi:10.1126/sciadv.aba7599
- Fact Sheet: Recycling of Plastic Films through Solvent Targeted Recovery and Precipitation
- UW-Madison researchers map out a promising future for solvent-based plastics recycling
- Mellow the yellow: New techniques clarify recycled plastic, increasing their value
- With innovation and determination, grad students drive new plastics recycling applications
- New solvent-based multi-layer plastic recycling process could cut down on millions of tons of plastic waste