Researchers from the University of Delaware are combining thermoset polymers with carbon fiber to make a composite for their new technique: localized inplane thermal assisted (LITA) 3D printing. Carbon fibers are strategically positioned with spaces to be filled with a liquid polymer that “wicks” into the material structure. Polymers may also fill the fibers if they are porous enough. The fibers are then heated, curing the liquid polymer and allowing for a 3D printed structure to form.
“Heating also decreases the viscosity of the polymer, changing its physical properties, and helps the polymer flow easily. Heating also helps the polymer to completely wet the fibers without forming voids,” author Lakshmi Supriya, PhD. explains in her paper, “Cost Efficient LITA 3D Printing Technology for Polymer Composites.”
With the strength of the carbon fibers, the polymer is improved; however, in most cases up until Supriya and her research team created their new technique, thermoplastics have been relied on as they melt easily when exposed to higher temperatures. They often do not exhibit good mechanical properties though—and especially if reinforcement fibers are not continuous, leading Supriya and the research team to expect much better results with this composite, bolstered by continuous carbon fibers. Other effective composites being used in 3D printing too may rely on other metal fillers and fibers or inorganic molecules. The whole point is usually to make a stronger part that is also lightweight.
One of the most beneficial and unique aspects of LITA 3D printing is that because curing occurs earlier in the process, it is not required later—meaning new savings in time and energy for users; in fact, up to several hours could be saved in eliminating that step. The process is faster overall too, as well as offering “reliability and repeatability in making complex shapes.”
Robotics are also employed here in a system comprised of a printhead that holds carbon fibers, a Joule heater, and distributes resin. A robotic arm is responsible for all movement of the printhead, working on substrates or in free space. The researchers 3D printed a variety of samples during the study, to include a 2D substrate, a 3D star, and conformal printing on a cylindrical rod. Ultimately, they reported having the best success in terms of tensile strength with industrial-grade carbon fibers and liquid epoxy.
These materials and the new technique may prove to be promising in applications in infrastructure such as building bridges, as well as aeronautics in creating parts for planes. The researchers expect that this new technique will also cut down on labor, tooling, and costs associated with defects.
While the majority of carbon fiber 3D printing processes on the market rely on thermoplastics, LITA is not the first technology to combine thermosets with continuous carbon fiber reinforcement. In particular, Continuous Composites uses a seven-axis robotic arm to cure a thermoset resin as printing takes place.[Source / Images: “Cost Efficient LITA 3D Printing Technology for Polymer Composites” ; AZO Materials]
You May Also Like
ICAM 2021: Keynotes on 3D Printing in Healthcare & Aerospace
At last month’s International Conference on Additive Manufacturing (ICAM) 2021 in Anaheim, California, hosted by ASTM International’s Additive Manufacturing Center of Excellence (AMCOE), a wide variety of topics were covered,...
3D Printing Unicorns: Gelato Gets $240M in Funding, Expands into 3D Printing
On-demand printing platform Gelato, based in Oslo, Norway, achieved the coveted unicorn status after a new funding round. On August 16, 2021, the company announced it had raised $240 million...
US Army and Raytheon to Use 3D Systems Metal 3D Printing to Heat-Optimize Munitions
3D Systems (NYSE: DDD) has been chosen by defense contractor Raytheon and the U.S. Army’s central laboratory to help with a design optimization project. To do that, the 3D Systems’...
Raytheon Receives Funding for Aerospace 3D Printing of Optical Components
This spring, Ohio-based America Makes, the leading collaborative partner in additive technology research, discovery, and innovation for the US, announced its latest Project Call for AXIOM, or Additive for eXtreme Improvement...
View our broad assortment of in house and third party products.