A technology partnership headed up by composites specialist Nathan Armstrong, formerly founder and president of Motive Industries (maker of the Kestrel biocomposite car) who has been involved with 3-D printing since 1995 and ran a 3-D printing company in California, is working to develop a 3-D printing technology that will produce composite parts with continuous fiber reinforcement. Further, the technology, says Armstrong, would allow composites design engineers to bypass the traditional design iteration process and bring parts to fruition faster.
One of the limitations of 3-D printing to date, as far as composites have been concerned, has been that additive manufacturing systems – by virtue of their layered build-up production process — could only produce composite parts reinforced with discontinuous fibers. This limited the application potential of the technology and locked 3-D printing out of high-performance markets like aerospace, auto racing, robotics and medical applications.
Armstrong says the technology on which he is working employs a proprietary process that uses carbon fiber-reinforced thermoplastic filament that is “placed optimally and continuously” in a 6-axis printer in “free space” that allows the machine to produce, ultimately, a continuous fiber structure. The system also allows for more complex parts to be built with multiple parts that are subsequently consolidated together. Further, additional heads will allow in-process stitching and weaving of fibers.
Parts coming out of the 3-D printer might be considered “green” and thus could require time in a pressurized tool with a heat cycle for consolidation. However, says, Armstrong, this process is still being tested and might only be required for high-performance parts.
The design aspect of this 3-D system also features innovations that Armstrong believes could change substantially how composite components are manufactured. Armstrong envisions the design process starting in any of a number of the structural optimization software packages on the market today. This design then would be fed into “feedback loop” software Armstrong has developed that iteratively calculates part optimization vs. fiber placement to make the part manufactureable in a 3-D free space. Once this feedback loop process is complete, the 3-D printing process can begin.
Armstrong argues that his feedback loop software obviates the need for typical design optimization. “It skips the entire traditional engineering design process and produces highly optimised parts with zero material waste,” he says. “I believe this is the future of manufacturing structural composite parts.”
This combined design/3-D printing system, Armstrong estimates, will come to market in a three- to five-year timeframe. In the meantime, he is seeking software partners to help finish developing the design process. He’s also seeking financial partners who want to invest in the effort. Armstrong can be reached at email@example.com.