本論文研究主要分為兩大類，首先是熔融沈積成型中使用的線材。原料聚乳酸3D870擠出成型為線材時受擠出參數的影響很大。因此，必須適當選擇參數以增強最終產品的特性。本研究通過實驗和統計研究了各種擠出參數，針對烘料溫度、烘料時間、擠出機溫度、擠出速度等對聚乳酸線材拉伸強度的影響。根據田口法的組合參數選取L9正交表的三水準四因子模型設計，擠出9種不同因子混合參數的線材。每種線材列印5個試片，試片規格為ISO-527-5A，共9組45個試片。將試片使用IMADA MX2電動拉力試驗座上進行拉伸試驗。拉伸試驗產出的數據使用Minitab軟體中的（Design of Experiment）DOE實驗設計田口法望大特性，輸入拉伸強度數據，得到最大訊噪比擠出溫度185°C，擠出速度每分鐘1195mm，烘料溫度50°C，烘料時間3小時的組合與標準差以及變異數分析。因為訊噪比越大，越穩健。從實驗結果可以證實，擠出溫度與擠出速度對聚乳酸線材的拉伸強度影響最大。
後者將原先拉斷試片及線材剪碎，剪碎後的聚乳酸3D870使用最佳化的參數擠出線材。三次回收的線材列印各5個試片並使用電動拉力試驗座上進行拉伸試驗。比較原始線材與三次回收線材在拉伸數據應力應變及模型尺寸精度上的差異。實驗結果表明，回收三次聚乳酸3D870線材使用最佳化參數情況下拉伸強度下降<3%內。證實優化線材製造參數可避免拉伸強度大幅度下降是成立的。

The study is divided into two categories mainly, The first is used in fused deposition modeling of the wire material. The raw material polylactic acid 3D870 is affected greatly by extrusion parameters when it is extruded into a wire. Therefore, parameters must be properly selected to enhance the properties of the final product. In this study, various extrusion parameters were investigated by experiment and statistic, aiming the influence of baking temperature, baking time, extruder temperature, extrusion speed, etc. on the tensile strength of PLA filament. According to the combination parameters of the Taguchi method, it's selected three-levels and four-factors model design of the L9 orthogonal table, and extrude filament with 9 different factor blend parameters. 5 test pieces are printed for each wire, the test piece specification is ISO-527-5A, a total of 9 groups of 45 test pieces. The test pieces were subjected to tensile tests using an IMADA MX2 Electric tensile test stand. The data produced by the tensile test used the (Design of Experiment) DOE experimental design by the Minitab software, and the data of the tensile strength was input to obtain the maximum signal-to-noise ratio extrusion temperature is 185°C, the extrusion speed is 1195mm per minute, the baking temperature is 50°C, and the baking time is 3 hours combination standard deviation and variance analysis. Because the higher the signal-to-noise ratio, the more robust. It can be seen from the experimental results that the extrusion speed has the greatest influence on the tensile strength of the PLA filament.
The second will cut the original broken test piece and wire into pieces, and the shredded 3D870 uses the optimized parameters to extrude the filament. 5 test pieces were printed out of the three times recycled filament rod and tensile test was carried out on a electric tensile test stand. Comparing the difference between the original filament rod and the three times recycled filament rod in tensile data stress strain and model dimensional accuracy. The experimental results show that the tensile strength of the 3D870 PLA 3D870 wire recycled three times is less than <3% when the optimized parameters are used. It is established that optimizing the wire manufacturing parameters can avoid a large drop in tensile strength.

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