Recycling plastics is one way to keep landfills from over flowing, but the technology is still primitive. Most methods merely chop up plastics, rather than break them down into their molecular building blocks, called monomers. The few processes that do turn plastics back into monomers work on only one kind at a time. As a result, recycled plastics are used mainly as fillers, making up no more than about 10% of the volume of new plastic materials, so that they don't compromise strength and other key properties, says Mark Paisley, a project manager at Battelle Memorial Institute.
Paisley's group has a better way. Mixed, chopped-up plastics are put into a reactor and processed so that they come out as a gas stream made up of the different kinds of monomers. These are separated and recombined to form new plastics that can be made of 100% recycled material without loss of strength or quality. So far, the process works in an experiment that handles about 20 pounds of plastics an hour. Battelle is looking for a development partner to help scale up the process.