本研究使用化學熱浸式超音波輔助後處理進行積層製造MJF PA12與SLS TPU之後處理研究，並分別以脊椎側彎背架以及晶格結構鞋墊作為後處理應用。除了探討列印件經過後處理之表面形貌、表面粗糙度以及表面微觀情形，同時也將分析材料之機械性質變化。此外本研究以AMT(Additive Manufacturing Technologies)公司作為比較對象，分析不同後處理製程技術之處理效果差異。
本研究利用漢森溶解度參數查找與PA12和TPU材料溶解度相符之化學溶劑，溶劑包含二甲基乙醯胺和苯氧乙醇。研究結果顯示，兩種溶劑以60/40wt%濃度可得到較佳之表面品質，後續在PA12脊椎側彎背架進行後處理可以成功改善表面粗糙度，以140℃和處理時間5分鐘可以得到最佳的Ra 1.52µm。而TPU方面，則是以90℃和處理時間0.5分鐘可以獲得最好的Ra 0.62µm，並且能成功應用於晶格結構鞋墊。從實驗過程得知，PA12表面平滑機制是由於化學溶劑中的強氫鍵於表面反應形成液態溶劑薄膜；然而TPU表面平滑機制則是以化學溶劑溶解材料表面之後再結晶進而形成平滑表面。在機械性質方面，PA12經過後處理之後雖然拉伸強度略有降低，不過其在斷裂伸長率有所增加，顯示出材料增加其彈性性質。而TPU經過後處理之後，在拉伸強度與斷裂伸長率皆有顯著降低，顯示出材料從原先較為彈性特質轉變為脆性特質。綜合以上結果可以證明本研究開發之化學熱浸式超音波輔助後處理能有效改善粉床式積層製造列印件表面品質，並能應用於較複雜之3D大物件後處理，可望在未來開發出此後處理之商用設備，達成高速積層製造大量生產之目標。

In this study, the post-processing research of MJF PA12 and SLS TPU was carried out by using chemical hot-dipping ultrasonic-assisted post-processing, and the scoliosis back frame and lattice structure insole were used as post-processing applications respectively. In addition to discussing the surface morphology, surface roughness, and surface microscopic conditions of the printed parts after post-processing, the mechanical properties of the materials will also be analyzed. In addition, this study takes AMT (Additive Manufacturing Technologies) as the comparison object to analyze the differences in the treatment effects of different post-processing technologies.
In this study, Hansen solubility parameters were used to find chemical solvents that matched the solubility of PA12 and TPU materials. The solvents included DMAC and Phenoxyethanol. The research results show that the two solvents can obtain better surface quality at the concentration of 60/40wt%, and the subsequent post-treatment on the PA12 scoliosis back frame can successfully improve the surface roughness with the best Ra 1.52µm by 140℃ and a processing time of 5 minutes. As for TPU, the best Ra 0.62µm can be obtained at 90°C and a processing time of 0.5 minutes, and it can be successfully applied to lattice structure insoles. From the experimental process, it is known that the surface smoothing mechanism of PA12 is due to the strong hydrogen bonds in the chemical solvent reacting on the surface to form a liquid solvent film; however, the surface smoothing mechanism of TPU is to dissolve the surface of the material with a chemical solvent and then recrystallize to form a smooth surface. In terms of mechanical properties, although the tensile strength of PA12 is slightly reduced after post-treatment, its elongation at break increases, showing that the material increases its elastic properties. After TPU is post-treated, both the tensile strength and elongation at break are significantly reduced, showing that the material has changed from the original relatively elastic properties to the brittle properties. Based on the above results, it can be proved that the chemical hot-dipping ultrasonic-assisted post-processing developed in this research can effectively improve the surface quality of powder-bed additive manufacturing printed parts, and can be applied to the post-processing of more complex 3D large objects. It is expected to developed post-processing commercial equipment in the future to achieve the goal of high-speed additive manufacturing and mass production.

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