Scientists at the Department of Energy’s Oak Ridge National Laboratory have created a recipe for a renewable 3D printing feedstock that could spur a profitable new use for an intractable biorefinery byproduct: lignin.
The discovery, detailed in Science Advances, expands ORNL’s achievements in lowering the cost of bioproducts by creating novel uses for lignin—the material left over from the processing of biomass. Lignin gives plants rigidity and also makes biomass resistant to being broken down into useful products.
“Finding new uses for lignin can improve the economics of the entire biorefining process,” said ORNL project lead Amit Naskar.
Researchers combined a melt-stable hardwood lignin with conventional plastic, a low-melting nylon, and carbon fiber to create a composite with just the right characteristics for extrusion and weld strength between layers during the printing process, as well as excellent mechanical properties.
The work is tricky. Lignin chars easily; unlike workhorse composites like acrylonitrile-butadiene-styrene (ABS) that are made of petroleum-based thermoplastics, lignin can only be heated to a certain temperature for softening and extrusion from a 3D-printing nozzle. Prolonged exposure to heat dramatically increases its viscosity—it becomes too thick to be extruded easily.
But when researchers combined lignin with nylon, they found a surprising result: the composite’s room temperature stiffness increased while its melt viscosity decreased. The lignin-nylon material had tensile strength similar to nylon alone and lower viscosity, in fact, than conventional ABS or high impact polystyrene.
The scientists conducted neutron scattering at the High Flux Isotope Reactor and used advanced microscopy at the Center for Nanophase Materials Science—both DOE Office of Science User Facilities at ORNL—to explore the composite’s molecular structure. They found that the combination of lignin and nylon “appeared to have almost a lubrication or plasticizing effect on the composite,” noted Naskar.
“Structural characteristics of lignin are critical to enhance 3D printability of the materials,” said ORNL’s Ngoc Nguyen who collaborated on the project.
Scientists were also able to mix in a higher percentage of lignin—40 to 50 percent by weight—a new achievement in the quest for a lignin-based printing material. ORNL scientists then added 4 to 16 percent carbon fiber into the mix. The new composite heats up more easily, flows faster for speedier printing, and results in a stronger product.
“ORNL’s world-class capabilities in materials characterization and synthesis are essential to the challenge of transforming byproducts like lignin into coproducts, generating potential new revenue streams for industry and creating novel renewable composites for advanced manufacturing,” said Moe Khaleel, associate laboratory director for Energy and Environmental Sciences.
The lignin-nylon composite is patent-pending and work is ongoing to refine the material and find other ways to process it.
The Latest on: 3D printing feedstock
via Google News
The Latest on: 3D printing feedstock
- Additec Introduces New Compact Metal Desktop 3D Printer on December 21, 2018 at 9:38 am
Metal 3D printing is slowly becoming less expensive ... the controller can automatically return to the point of failure, trim the wire feedstock and restart the process. According to Additec ... […]
- New composite advances lignin renewable 3D printing material on December 21, 2018 at 4:41 am
Scientists at the Department of Energy’s Oak Ridge National Laboratory have created a recipe for a renewable 3D printing feedstock that could spur a profitable new use for an intractable biorefinery b... […]
- New composite advances lignin as a renewable 3D printing material on December 20, 2018 at 11:10 am
Scientists have created a recipe for a renewable 3D printing feedstock that could spur a profitable new use for an intractable biorefinery byproduct: lignin. Scientists at the Department of Energy's O... […]
- How Safe are the Titanium Powders Used in 3D Printing? on December 18, 2018 at 9:46 am
Despite the fact that the build phase of metal additive manufacturing is an enclosed process, the researchers point out, 3D printer operators may be exposed through inhalation to metal feedstock ... […]
- Working with refugees to tap creative potential on December 17, 2018 at 8:10 pm
Chan and the team refined plastic waste from discarded plastic bottles to create 3D printing feedstock in the form of filaments. Young people from the camps engaged with the project then designed and ... […]
- New research finds potential health impact from consumer FDM 3D printers on December 17, 2018 at 1:53 pm
Tests employing a standardized emission chamber and data analysis protocol showed that 3D printing produced high concentrations ... For example, the most widely used feedstock material, acrylonitrile ... […]
- Tethers Unlimited Inc. delivers 3D printer, plastic recycler hybrid to NASA on December 17, 2018 at 8:56 am
After which, the integrated 3D printer fabricates new parts from the recycled filament ... “Without a recycling capability, a large supply of feedstock would need to be stowed onboard for long-duratio... […]
- A Guide to the Materials and Methods Required for Additive Manufacturing (AM) on December 9, 2018 at 11:07 pm
H.C. Starck produces wire feedstock from its conventional range of refractory ... achieved due to the fact the printing layers are thicker than those used in the 3D screen printing technique. This met... […]
- 3D printing surging globally and South Africa is making its mark on December 6, 2018 at 2:12 pm
The global takeoff of additive manufacturing (AM, popularly called three-dimensional, or 3D, printing), it is now apparent ... there is now a much wider range of materials that can be used as feedstoc... […]
- Gentle reminder: 3D Printing by DNV GL and Ivaldi 14 November on November 9, 2018 at 7:31 am
Additive manufacturing (AM), also known as 3D printing, progressively builds up products from raw materials such as metal powder feedstock or a wire, can transform the business models of many industri... […]
via Bing News