The additive manufacturing industry shows annual growth of more than 10 %. Therefore, the requirements for produced components are increasing, especially for individual medical technology applications printed from poly(ether ether ketone) (PEEK). This paper focuses on an investigation of an uninterrupted nozzle system for printing the high-performance thermoplastic PEEK with short fiber reinforcements. A custom-made nozzle design with variable outlet angle is presented and the achievable fiber length distribution and fiber orientation in the printed material are investigated. The applied nozzle angles are 60 °, 90 ° and 120 °. The geometric shape of the tip of the custom-made nozzles is comparable to that of a reference nozzle. With regard to the height profile, the inner surface is up to three times smoother. With a decreasing nozzle angle, a lower degree of fiber damage caused by deposition can be demonstrated. Thus, the process-induced shortening of the fibers decreases. The enhanced flow profile for small angles outweighs the simultaneous disadvantageous due to friction loss, shear stress and pressure drop. A clear result for the fiber orientation cannot be deduced. © 2021 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.

中文翻译：

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不同喷嘴形状的印刷碳纤维/聚（醚醚酮）的纤维形成

增材制造行业的年增长率超过 10%。因此，对生产组件的要求越来越高，尤其是对于由聚醚醚酮 (PEEK) 打印的单个医疗技术应用。本文重点研究用于打印具有短纤维增强材料的高性能热塑性 PEEK 的不间断喷嘴系统。提出了具有可变出口角度的定制喷嘴设计，并研究了打印材料中可实现的纤维长度分布和纤维取向。适用的喷嘴角度为 60°、90° 和 120°。定制喷嘴尖端的几何形状与参考喷嘴的几何形状相当。就高度轮廓而言，内表面最多平滑三倍。随着喷嘴角度的减小，可以证明沉积引起的纤维损伤程度较低。因此，过程引起的纤维缩短减少。由于摩擦损失、剪切应力和压降，小角度增强的流动剖面超过了同时带来的不利影响。不能推导出纤维取向的明确结果。© 2021 作者。由 John Wiley & Sons Ltd 代表工业化学学会出版的Polymer International。