In Tennessee, a scalable processing technique developed by Oak Ridge National Laboratory uses plant-based materials for 3D printing and offers a promising additional revenue stream for biorefineries. Scientists created a new material with excellent printability and performance by tapping into lignin—a current byproduct of the biofuels process.
Credit: Ngoc Nguyen/Oak Ridge National Laboratory, U.S. Dept. of Energy
Lignin is a natural resource with huge potential. It is a class of complex organic polymers that form important structural materials in the support tissues of vascular plants and some algae. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Lignin is also the second most abundant natural polymer in the world, surpassed only by cellulose. Therefore Lignin could become a valuable coproduct with its use as a 3D printing material.
ORNL's method combines lignin, rubber, carbon fiber and acrylonitrile butadiene styrene, or ABS to 3D print structures with 100 percent improved weld strength between the layers over ABS alone.
The micrograph shows a cross-section of the weld area between two 3D-printed layers of a plant-based composite material developed by Oak Ridge National Laboratory. Credit: Christopher Bowland/Oak Ridge National Laboratory, U.S. Dept. of Energy
“To achieve this, we are building on our experience with lignin during the last five years,” said ORNL’s Amit Naskar. “We will continue fine tuning the material’s composition to make it even stronger.” The research team published details about the patent-pending process in a paper entitled “A general method to improve 3D-printability and inter-layer adhesion in lignin-based composites” in Applied Materials Today.