Recycling Flexible Packaging Waste by Solvent-Targeted Recovery and Precipitation (STRAP)

Presented by Reid Van Lehn, University of Wisconsin-Madison

The Solvent-Targeted Recovery and Precipitation (STRAP) process is a platform technology for recycling multicomponent plastic waste, including multilayer plastic films. In this talk, I will describe the basic principles of the STRAP process, in which target polymer components from multilayer plastic films are recovered using sequential solvent washes. Each wash is designed to selectively dissolve a single component from the waste, which can then be recovered after precipitation induced either by addition of an antisolvent or by lowering the temperature. The key technical challenge for STRAP is designing solvent compositions and process steps to achieve efficient and economical polymer recovery while avoiding impurities. We are addressing this challenge by integrating experimental and computational techniques to design possible solvent systems, predict process economics, and characterize recovered material. I will summarize our development of computational tools for solvent selection and their integration with process modeling tools. I will then describe recent experimental applications of STRAP to flexible packaging waste and the properties of films created from recovered materials.