Improved design of fused deposition modeling equipment for 3D printing of high-performance PEEK parts

•The temperature uniformity in printing area was improved with HC nozzle module.•The bending and tensile strength of PEEK part increased.•The warpage of PEEK parts edge decreased from 20.4% to 5.0%.•Effects of chamber temperature and HC nozzle on PEEK crystallinity were discussed. Polyether ether ketone (PEEK) is one of the most commonly used materials in medical transplantation, and additive manufacturing is particularly useful for fabricating transplants as it can be used to form complex, customized parts. The main difficulty in forming PEEK parts using additive manufacturing is the high melting temperature of PEEK materials, which makes parts undergo a large temperature change during forming. This produces large internal stress, warpage, and delamination. Several structural design improvements in the regular fused deposition modeling (FDM) equipment are proposed in present work based on results from finite element simulations and experiments. The nozzle is augmented by a heat collector, which can significantly improve the uniformity of the temperature field during printing and increase the final strength of formed parts. Meanwhile, a two-degree-of-freedom platform is designed to reduce warpage of the forming plate caused by the high ambient temperature. XRD results show that the specimens formed using the improved equipment have higher crystallinity. Mechanical tests show that the warpage rate of a specimen can decrease from 20.4% to 5.0%, and the elastic modulus can increase by 20.1%.