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Researchers at the Department of Energy’s Oak Ridge National Laboratory (Oak Ridge, TN, US) have developed a renewable 3D printing feedstock using lignin, a biofuels byproduct. 

The group, led by Amit Naskar, reportedly combined a melt-stable hardwood lignin with conventional plastic, a low-melting nylon and carbon fiber to create a composite with the right characteristics for extrusion and weld strength between layers during the printing process, as well as good mechanical properties.

While lignin chars easily and can only be heated to a certain temperature for softening and extrusion from a 3D-printing nozzle, the researchers found that combining lignin with nylon increased the composite’s room temperature stiffness and decreased its melt viscosity. According to ORNL, the scientists were also able to mix in a higher percentage of lignin—40% to 50% by weight. They then added 4% to 16% carbon fiber. 

The lignin-nylon composite is patent-pending and work to refine the material and find other ways to process it continues. The research was funded by DOE’s Office of Energy Efficiency and Renewable Energy’s Bioenergy Technologies Office.