全新螺桿式粒材進料之聚醚醚酮積層製造機臺開發與應用

積層製造技術又稱三維積層或立體列印(3D printing)，一直被認為是未來科技發展的一大趨勢備受全球矚目，而熔融沉積成型(Fused deposition molding, FDM) 更是其中最被普遍應用、深具經濟價值之技術，其技術在於以擠出方式將半熔融材料列印於基板以實現各式結構。儘管其具有成本低、製程簡單、快速完成等優勢，但其製程仍受諸多材料選擇之限制，例如無法用於具有生物相容性、高機械強度、抗化學性、高熔點及高黏度(>100,000 cP)之聚醚醚酮(polyetheretherketone, PEEK)高分子材料。故本研究旨在開發一可商用FDM型PEEK 3D列印機。目前市售之FDM型3D列印機臺，主要皆以線材送料式擠出，此送料方式在高速列印時易有噴嘴堵塞之問題及線材不穩定挫曲的情形發生(因熔料逆流所導致)，從而限制其列印效率。因此，本研究捨棄線材送料方式，率先成功開發一全新粒材直接進料、輔以射出成型螺桿式擠出之聚醚醚酮3D列印機臺，其特點在於整合供料擠線製程及提供更大穩定扭力，以根本解決熔料逆流與列印不穩定之瓶頸。目前機臺成功突破一般FDM不利快速列印之侷限(一般上限僅約50 mm/s)，在400 μm噴嘴下，可進行370 mm/s之高速列印(列印速度提升7.4倍)，且流量誤差控制於3%下。而憑藉此系統設計之優越與穩定性，本文所列印出的產品，能大幅有效抑制試片內部的孔洞因製程缺陷之產生機率並強化機械強度，其機械強度測試在文獻中已首度可達塊材之96%! 而為擴大機臺功能，本研究也開發出可替換式面型列印模組，用以大面積快速列印，列印出之最小膜厚為58 μm，表面粗糙度(Ra)均可達4 nm以下。而為展現此PEEK列印機臺於微流體平臺應用的特殊價值，本文特別測試了需抗化學反應的光調控分子合成實驗，所製作之微反應器成功證實可改善傳統耗時、低產率(約61%)之批次製造，達到高效反應(95%)與連續生產之成果。最後，本研究也成功列印出高深寬比空心101及內部網狀通道椎間融合器。

關鍵字

積層製造；聚醚醚酮；螺桿式粒材進料擠出；高信賴度列印機臺；抗化學性微反應器應用

並列摘要

Additive manufacturing (AM), also known as 3D printing, has been recognized as the next big thing of future technology in the recent years. Among all the related methods, fused deposition molding (FDM) is one of the most economical way, which extrudes the semi-molten material onto the substrate to construct artificial structures. Despite it has several benefits including of low cost, user-friendly, and rapid printing, it still suffers from a severe limitation on printing material, especially for the high viscous polymer (> 100,000 cP) such as polyetheretherketone (PEEK) with biocompatible, high mechanical strength, and chemical resistant properties. To this end, this study aims for developing the commercial 3D printer based on FDM for PEEK material. In addition, commercial available FDM 3D printer mainly uses the mechanism of filament feeding, which has drawbacks of back-flow induced nozzle clogging and filament bulking phenomenon in high speed printing process, thus restricting its printing efficiency. Therefore, in this study, skipping the commonly used filament feeding in FDM for the first time, we’ve successfully developed pellet-based and screw-typed 3D printer for PEEK material in the injection molding concept with features of easy operation (saving one process on pellet to filament) and maintenance (no more nozzle clogging). Furthermore, the current apparatus supports the printing speed up to 370 mm/s with flow rate error controlled within 3% while conventional method is only 50 mm/s in 400 μm nozzle diameter. On the basis of this approach, we have successfully printed some specimens and the porosity induced by process imperfection can be greatly inhibited and the mechanical strength can be enhanced up to 96% in tensile strength compared to the bulk material in the first time. In addition, we also developed an exchangeable plane-typed printing head for large-area printing. Currently, the minimum dry film has achieved the maximum precision of 58 μm and the best surface roughness Ra has achieved in 1.56 nm. To further demonstrates PEEK printer’s superiorities in the application of microfluidic device. This study also designed and printed the chemical resistant micro-reactor for the synthesis of liquid crystal and optically active molecules. The results show a higher yield (95%) and reaction velocity (180 times) than the conventional batch method (61%). Finally, we have also successfully printed high aspect ratio structure (hollowed Taipei 101) and intervertebral cage with interconnected channel.

並列關鍵字

Additive manufacturing ； polyether-ether-ketone (PEEK) ； pellet-based and screw-typed extrusion ； highly reliability 3D printer ； chemical resistant micro-reactor applications

參考文獻

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全新螺桿式粒材進料之聚醚醚酮積層製造機臺開發與應用

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