THORNTON CLEVELEYS, U.K.—Victrex has developed two new materials—a high strength material for laser sintering (LS) and a filament reported to have better Z-strength than existing polyaryletherketone (PAEK) materials—that the company is preparing for use in additive manufacturing.
The high strength material for laser sintering attains lower refresh rates that result in improved recycling of unsintered powder, the company said in a press release. The filament material, in addition to having what is reported to be higher Z-strength than existing PAEK materials, is said to offer better printability for filament fusion (FF).
“These next-generation VICTREX PAEK materials for additive manufacturing mark a decisive step forward, having potential to transform multiple applications, including aerospace and medical,” said Victrex CEO Jakob Sigurdsson, in the press release. “The exciting progress is based on continued intense R&D at Victrex and excellent collaboration within the Victrex-led consortium of companies and institutions pursuing innovation in additive manufacturing. Through this consortium, we’re already seeing demonstrator parts that show how AM processes, coupled with high-performance materials, transform thinking to create truly innovative parts based on increased design possibilities.”
Advantages of additive manufacturing can be deployed to reduce costs, shorten time to market, and enable the production of parts too complex to be manufactured using traditional methods. Incumbent PAEK materials on the market today, although used in some AM applications, were designed for conventional manufacturing methods, such as machining and injection molding. As a result, they have some features that aren’t optimal for additive manufacturing processes.
A first generation of PAEK material for laser sintering can only be recycled to a very low extent, the company said, and requires nearly a full refreshing of the printing bed with new powder. At the same time, PEEK filaments available for filament fusion have poor interlayer bonding, leading to a loss in Z-strength.
The new polymer grades developed by Victrex are reported to have shown “encouragingly low refresh rates,” which improve recycling of unsintered powder, with similar mechanical properties in laser sintering. In filament fusion, they have shown “good mechanical properties and printability,” according to Victrex.
“Breakthrough technology is paving the way for an exciting future for additive manufacturing [of] PAEK,” said Victrex Chief Scientist John Grasmeder. “The powder recycle work for laser sintering, using the new Victrex development polymer grades, has gone very well, with no measurable loss of properties when test components were made from partially recycled powder. We believe it will be possible to re-use all of the non-sintered powder that is recovered after a build run. This will result in a significant reduction in material costs compared to current PAEK materials, where up to 40 percent of the polymer is wasted and cannot be recycled.”