By Katharine Webster
When it comes to recycling, getting people to participate is just the first challenge. Turning that recyclable waste into high-quality products is a much bigger problem.
Assoc. Prof. Meg Sobkowicz-Kline of the Department of Plastics Engineering is tackling that challenge as the university’s representative to the REMADE (Reducing Embodied Energy And Decreasing Emissions) Institute.
“We’re trying to increase the recyclability of plastic waste streams,” Sobkowicz-Kline says.
The REMADE Institute was created two years ago under the Manufacturing USA initiative, which brings together universities, corporations and government agencies on research projects that involve innovation in manufacturing.
REMADE recently awarded its first round of grants, including $200,000 to Sobkowicz-Kline and researchers from Michigan State University, the National Renewable Energy Laboratory, the American Chemistry Council and Unilever. They plan to study whether layered films, like those used for packaging food, can be separated into their component materials for recycling, or whether chemical processing and high-speed extrusion can turn some of the films into recycled products, such as adhesives and coatings.
Improvements in plastics recycling are especially urgent because China banned nearly all imports of recyclable plastics at the beginning of 2018, saying the blocks of crushed bottles and containers from other countries were too often contaminated with other undesirable materials, such as Styrofoam and plastic grocery bags.
The U.S. sends about one-third of its recyclable materials overseas, and China was the biggest consumer before Jan. 1. So now, American companies are scrambling to find other markets – and increase the U.S. market, too. In the meantime, some of the plastics Americans put in their recycling bins have effectively become garbage, notes Sobkowicz-Kline.
“We’re starting to landfill our recyclables in this country,” she says. “There’s nowhere else for them to go.”
Sobkowicz-Kline is an expert in plastics manufacturing processes, especially high-speed extrusion. Much of her previous research involves bioplastics – polymers made from natural materials that are biodegradable. Among other projects, she is working on biodegradable plastics for the agriculture industry.
Now she wants to see if high-speed extrusion will conquer two of the biggest problems in plastics recycling: mixed materials and contamination.
Some plastics are easy to recycle because they’re made of a single material that can be melted down and re-formed, she explains. Plastic soda bottles and milk jugs, labeled with a “1” or “2” inside the recycling symbol, are examples of high-quality recyclables.
“In plastics, our paradigm has been: Collect it, melt it down and reuse it,” Sobkowicz-Kline says.
Other plastics are compounds made by mixing materials. Still others are layered, often with paper or foil, like the food wrappings used for many grocery products. These are nearly impossible to recycle using current technology.
Finally, there’s the problem that China complained of: contamination. Even the best-quality plastics are difficult to recycle if they’re not thoroughly sorted and other materials end up in the mix.
Sobkowicz-Kline says high-speed extrusion may keep some mixed materials together or reduce the impact of contamination, compared to the standard extrusion process now used by most manufacturers. High-speed extrusion also uses less electricity, reducing emissions from fossil fuels and reducing energy costs for manufacturers, she says. That’s key to getting industries to adopt it.
Outside of REMADE, Sobkowicz-Kline and plastics engineering Asst. Prof. Javier Vera-Sorroche have obtained an $18,000 grant from the Health Care Packaging Recycling Council for a test project to see if they can apply high-speed extrusion to recycling the plastic wrap that hospitals and medical offices use to keep medical instruments sterile. The wrap never touches patients, but the amount of waste generated is enormous, since virtually every instrument is covered in plastic that’s discarded after each procedure and patient.
“Medical packaging holds a lot of promise,” Sobkowicz-Kline says. “It’s a very clean waste stream.”
Sobkowicz-Kline says she is looking for more partners in industry, as well as UMass Lowell researchers, to come up with proposals for REMADE that meet the institute’s goal: reducing the waste stream by recycling more materials using energy-efficient methods. REMADE isn’t limited to plastics – the institute is also seeking proposals for better recycling of metals, electronic waste and fibers.
“This is a huge opportunity,” she says. “Anybody can apply for this.”
To learn more about issues in plastics recycling, visit Sobkowicz-Kline’s educational website, www.plasticsfacts.com.