Hanemann Thomas, Klein Alexander, Baumgärtner Siegfried, Jung Judith, Wilhelm David, Antusch Steffen
Institute for Applied Materials, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
Department of Microsystems Engineering, University Freiburg, Georges-Koehler-Allee 102, D-79110 Freiburg, Germany.
Polymers (Basel). 2025 Apr 16;17(8):1069. doi: 10.3390/polym17081069.
Poly(ether ketone ketone) (PEKK), as a representative of high-performance poly(aryl ether ketones), shows outstanding thermomechanical properties, opening up a huge range of different applications in various technical fields. Its appearance as a quasi-amorphous polymer with a certain suppression of the crystallization process facilitates melt processing via additive manufacturing processes like material extrusion (MEX), especially in fused filament fabrication (FFF). The quality of the printing process is proven in this work by tensile testing and surface roughness measurements of suitable specimens. The MEX printing of semicrystalline PEKK faces two major challenges: on the one hand, the very high printing temperature is in contrast to established engineering plastics, and on the other hand, it is difficult to avoid crystallization after printing. The first issue can be addressed by using suitably enhanced MEX printers and the second one by selecting adapted printing parameters. The measured Young's modulus (3.49 GPa) and tensile strength (104 MPa) values are higher than the related vendors' data given for filaments (3.0 GPa and 92 MPa, respectively). In addition, the temperature-dependent thermal conductivity is determined, and the values of well-established PEEK (poly(ether ether ketone)) in the temperature range from 20 to 180 °C are mostly slightly higher in comparison to the related PEKK data. Based on the results, PEKK can be a useful substitute for well-established PEEK because of their comparable properties. However, PEKK has a pronouncedly lower FFF printing temperature, combined with a reduced tendency of the device to warp after printing. A larger printed test part with some surface structures shows the improved printability of PEKK in comparison to PEEK.
聚醚酮酮（PEKK）作为高性能聚芳醚酮的代表，具有出色的热机械性能，在各种技术领域开辟了大量不同的应用。它以准无定形聚合物的形式出现，对结晶过程有一定抑制作用，这有利于通过材料挤出（MEX）等增材制造工艺进行熔融加工，尤其是在熔丝制造（FFF）中。通过对合适试样进行拉伸测试和表面粗糙度测量，证明了该打印工艺的质量。半结晶PEKK的MEX打印面临两个主要挑战：一方面，与成熟的工程塑料相比，打印温度非常高；另一方面，打印后难以避免结晶。第一个问题可以通过使用适当增强的MEX打印机来解决，第二个问题可以通过选择合适的打印参数来解决。测得的杨氏模量（3.49 GPa）和拉伸强度（104 MPa）值高于相关供应商给出的长丝数据（分别为3.0 GPa和92 MPa）。此外，还测定了温度依赖性热导率，在20至180°C温度范围内，成熟的聚醚醚酮（PEEK）的值与相关PEKK数据相比大多略高。基于这些结果，由于性能相当，PEKK可以成为成熟的PEEK的有用替代品。然而，PEKK的FFF打印温度明显更低，且打印后设备翘曲的趋势降低。一个带有一些表面结构的较大打印测试部件显示，与PEEK相比，PEKK的可打印性有所提高。
