複合中空纖維熔融紡絲之研究

The Study of the Processing of Conjugated Hollow Fibers

吳嵐櫻(Lan-Ying Wu)

指導教授 ： 蘇淵源

國立臺北科技大學/工程學院/化學工程研究所/碩士(2007年)

摘要

近年來，紡織業者紛紛投入功能型纖維之開發，如異形纖維、複合纖維以及中空纖維。結合兩種纖維以上特性之複合中空纖維，在生產加工過程中，有一定的困難度。為了提高產品開發成功的機率，本研究分別以兩種不同幾何形狀之模具如4T型模具和S/C型模具，模擬熔融複合高分子出模具後之流動行為，並找出成型的關鍵因素。
首先，以含有親水性官能基的Nylon、PET或CO-PET當作鞘層材料，而芯層材料則採用疏水性之PP系列。利用平板式流變儀及毛細管式流變儀，獲得材料的穩態及動態流變特性資料。在電腦模擬的部分，我們採用的是有限元素法，搭配optimesh-3D re-meshing的技巧來計算自由表面問題。數值方法的選用有牛頓疊代法、Picard疊代法，以及EVSS/SU。使用四種材料本質方程式如牛頓流體、Cross model、Maxwell model以及PTT model，來描述材料特性，進而探討黏度、黏度減稀性、彈性與流量對黏合情形和適紡性之影響。
我們發現黏合是成型的關鍵因素，影響黏合的要素除了融體的偏轉，另一項則是模口膨脹。控制融體偏轉的主因有流量比、黏度比和彈性度比，從中整理出如何減少偏轉程度的操作準則。另外，我們也探討了模口膨脹受彈性的影響。最後，我們將模擬結果和實驗結果做比較。

關鍵字

複合中空纖維 ； 4T型模具 ； S/C型模具 ； 黏度 ； 彈性

並列摘要

In recent years, the textile industry puts more and more investments on the research and design of functional fibers, such as profiled fibers, conjugated fibers and hollow fibers. However, there are some difficulties in the manufacturing of conjugated hollow fibers, possessing two or more kinds of fiber characteristics. In order to increase the successful chance of developing products, we chose two kinds of the die geometry, such as 4-T typed spinneret and sheath/core spinneret, to simulate the flow behavior of conjugated molten polymers co-extruding from the spinneret, and to find the key factors of forming fibers.
First, Nylon, PET, or CO-PET with hydrophilic function is the sheath layer material and a series of hydrophobic PP are respectively arranged as the core material. The rheological data of materials used in the study are measured by the parallel plate rheometer and the capillary rheometer. For the parts of computer simulation, we utilized the numerical approach of finite element method with optimesh-3D re-meshing to solve a free surface problem. The numerical algorithms used in the computations include Newtonian iteration, Picard iteration and EVSS/SU. To study viscosity, shear thinning and elasticity effects on the spinning behavior of the conjugated hollow fiber, four appropriate constitutive equations, for instance, Newtonian fluid, Cross model, Maxwell model and PTT model, are adopted in our simulations.
We find that the gluing is the key factor on forming fiber. Moreover, not only the die swell but also the deflection of molten streams is demonstrated to be the major factors, affecting the gluing process. For the polymer stream deflection, flow rate ratio, viscosity ratio and elasticity ratio are proved to be the controlling factors. From these factors, the operating windows are found to lessen the extent of deflection. In addition, we also confirm that the elasticity can influence the die swellings. Finally, the simulation results are compared with experimental data.

並列關鍵字

Conjugated Hollow Fiber ； 4-T typed spinneret ； Sheath/Core typed spinneret ； viscosity ； elasticity

參考文獻

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