Recycled Composites Intermediates Development
ORNL researchers are developing a methodology that processes recycled fibers with recycled resin systems in order to produce new nonwovens and reinforced thermoplastics. Converted thermoplastic can be turned into intermediate materials that are then fed into different manufacturing processes such as polymer additive manufacturing, injection, and compression molding. Research focuses on adapting existing compounding and textile tools for the consistent production of upcycled and recycled composite materials. Shredding and pelletizing equipment modifications produce optimized feedstocks for additive manufacturing, traditional molding processes or extrusions. Polymer properties are adjusted for processability and rheology, thermal stability, melt behavior and mechanical performance and, tailored for compatibility with specific manufacturing processes.
The manufacturing process produces a waste stream of excess polymers, resins or plastics. These unused materials can have extended purpose beyond one-time single use. ORNL researchers are developing techniques to repurpose high value plastics as additive manufacturing and composites feedstock. These techniques focus on pyrolysis and chemical recycling; classification and separation; bulk shredding and sorting; compounding and large-scale additive manufacturing. Research is dedicated to reclaiming high value products such as high- performance fibers, upcycling low-value plastics and recovering energy from non-reusables. Recovered materials can be used for additively manufactured parts and industrial molds such as precast concrete for construction; compression and/or injection molded components for vehicle light weighting, including automotive body paneling; and composite extrusion for infrastructure components such as composite decking.
Recycled Composites Manufacturing
More than 50 million pounds of carbon fiber scrap is landfilled annually in the world and the material has an up to 30 percent scrap rate. ORNL researchers are exploring many avenues for creating a circular process for composites so that materials are put back into use in the manufacturing process. Researchers focus on carbon fiber plastic composite manufacturing, closing the loop on recycled carbon fiber and converting to automotive panel use. Recent projects include recycling woven fiber into thermoplastic pellets and developing an automotive fender made out of recycled carbon fiber. Researchers also demonstrated that reclaimed polycarbonate waste reinforced with bamboo could be deployed in large-scale additive manufacturing to produce a printed utility pole.