Lignin is a complex organic polymer that is an important part of the cell walls of many plants, making them woody and rigid. It’s also a 3D printable material, much like cellulose, another building block in plant cells. Oak Ridge National Laboratory (ORNL), a research organization that has done a great deal of important work with 3D printing, has developed a new 3D printing material using lignin.
[Image: Ngoc Nguyen/Oak Ridge National Laboratory, U.S. Dept. of Energy]
The material is made by combining lignin, rubber, carbon fiber and ABS. Components 3D printed with the material have 100 percent improved weld strength between layers compared to ABS alone.
“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 details of the patent-pending process have been published in a paper entitled “A general method to improve 3D-printability and inter-layer adhesion in lignin-based composites,” which you can access here. Authors of the paper include Ngoc A. Nguyen, Christopher C. Boland, and Amit K. Naskar.
More of ORNL’s 3D printing expertise was in the spotlight recently as Secretary of Energy Rick Perry traveled to the facility to dedicate Summit, the world’s fastest and smartest scientific supercomputer. Perry didn’t stand at any ordinary wooden podium – he stood behind a futuristic 3D printed podium, courtesy of ORNL. With the exception of the microphone and the wiring, every part of the podium was 3D printed, using different technologies and materials.
The top of the podium was 3D printed with 20% carbon fiber ABS, using a Blue Gantry large-scale polymer deposition system. The printing took six hours, and then the piece was coated with a Tru-Design sand coat with clear paint and a flattening agent. The pedestal was 3D printed with 30% bamboo reinforced with 70% PLA, also using a Blue Gantry System and Tru-Design clear paint and a flattening agent. The component took three hours to 3D print. The Department of Energy seal on the podium was 3D printed from a titanium alloy using an Arcam electron beam melting system. It took nine hours and 44 minutes to print.
The podium is a showcase of the speed and effectiveness of 3D printing, no matter what the technology used. The complex DOE seal traditionally would have to be cast, but 3D printing it was much faster and did not require the use of a die. Attendees at the presentation were able to see how ORNL’s Manufacturing Demonstration Facility saved money, time and reduced waste through its use of technology. The final product is attractive, with a twisting, multi-sided brown pedestal and a silvery top with the DOE seal prominently displayed. It’s also a highly functional podium, sturdy and durable, with the advanced coatings applied to it making it resistant to rain, sun, or other outdoor elements.
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[Sources/Images: ORNL, Department of Energy]
