Solving the Impossible-Recycling Challenges
It has been known for over a decade that Solid-State Shear Pulverization (SSSP) can overcome many of the key challenges that face recycling post-consumer polymer waste. Major problems surrounding recycling post-consumer waste include incompatibility between the different polymers, viscosity mismatch, and contamination. Prior to 2014, there has been very little success in converting post-consumer waste streams back into useable materials. This work, for the first time, describes the successful commercialization of SSSP and its implementation in solving some of the most "impossible" recycling challenges, which include post-consumer laminated film (PCR), K-Cup (or single serve coffee), and ocean plastic waste.
Municipal recycling factories (MRFs) are struggling to find a solution to the growing post-consumer recycled laminated film (PCR) waste streams. The inability to recycle these streams is due to cross-contamination of various polymers and impurities in the waste steam. Furthermore, current technologies implemented at MRFs are not set up to handle and separate film based materials. Part of this project focused on processing uncleaned, unsorted PCR film back into recycled resin. It was shown that SSSP can successfully recycle PCR film back into useable pellets with good mechanical and flow properties, comparable to recycled high density polyethylene. Overall, this work led to the development of an injection mold grade PCR resin available for commercial use.
The convenience of a Keurig K-Cup comes at a price. Billions of non-recyclable Keurig K-Cups end up in landfills every year resulting in harmful effects on the environment. Co-founder John Sylvan stated, "I feel bad sometimes that I ever [invented the K-Cup]." Another part of this research utilized SSSP to recycle Keurig K-Cups back into usable materials. Ultimately, K-Cups were successfully converted at ~10 wt% into a PLA 3D printing filament.
Another environmental plague is that of ocean and beach plastic, which continues to accumulate across the planet. It is currently estimated that eight million tons of plastic ends up in the ocean every year. SSSP was also utilized to convert ocean and beach plastic into new, useful materials. Ocean and beach plastic was successfully converted back into low value plastic value resin at 10-40 wt%. Injection molded closures and 3D printed filament were produced.
Overall, SSSP has demonstrated the first commercially viable process to solve some of the biggest recycling challenges that face the planet.
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