鞘芯型複合纖維及非等溫4C型中空纖維熔融紡絲之數值模擬分析

Simulation Analysis of Sheath/Core Conjugated Fibers and Non-isothermal Hollow Fibers

蔡政諺(Cheng-Yan Tsai)

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(2010年)

摘要

本研究是利用有限元素法搭配optimesh-3D re-meshing及EVSS /SU數值技巧，針對鞘芯型複合纖維及非等溫中空纖維做模流分析。模擬所使用的材料分別為Co-Pet、Co-Nylon、Pet、Nylon6與聚丙烯，其材料參數則使用平板流變儀與毛細管流變儀測得之流變數據，經由polymat契合而獲得。
第一部分為複合纖維紡絲模流分析，此類導電纖維在紡紗中的偏心度不易控制進而影響紗線之收束性不佳。因此本文針對材料參數及紡絲條件對纖維偏心度之影響做討論。模擬結果得知，當材料黏度比提高，其末端纖維偏心度也會隨之變大，當流量比提高則反之，而紡絲板粗糙度增加也會使得纖維偏心度提高。
經由4C型紡嘴製作中空纖維模擬，此方法為現今中空纖維重要製程之一，紡絲過程中非等溫的邊界條件對材料性質的影響，使得紡出中空纖維之強度及中空率的掌控不易，乃致影響其後續應用之效能。因此針對流變性質、模溫、4C裂縫寬度及吐絲量對黏合長度、黏合溫度以及中空率的影響作有系統的探討。結果發現當紡嘴溫度提高，吐絲量大者黏合長度有縮短的趨勢，吐絲量小者則反之。且增加吐絲量有助於提高黏合溫度，能有較佳的黏合效果。而材料黏度較低者，其黏合溫度較低；在低吐絲量時，黏合長度需較長。中空率的變化中，一出紡口即會驟降，之後再緩緩上升。

關鍵字

偏心度 ； 鞘芯纖維 ； 黏彈性 ； 4C型 ； 中空纖維

並列摘要

Our study analyzes the fluid stimulation (FS) of sheath/core conjugated fibers and non-isothermal hollow fibers by utilizing the finite element method as well as, optimesh-3D re-meshing and EVSS/SU numerical techniques. Co-Pet, Co-Nylon, Pet, Nylon6 and polypropylene were separately used in the stimulation. According to the rheological data obtained by both plate and capillary rheometers, each material parameter would be presented via polymat fitting.
In the FS analysis for the conjugated fiber spinning, the eccentric percentage (EP) of the conductive fiber was hard to control and further led to the low level of manufacture in yarn. Therefore, the objective of this research is to discuss the effects of the material parameters and spinning conditions on the EP of fibers. Based on the FS consequence, the increase of material viscosity ratio and die roughness, lead to elevate EP in the end of fiber. However, higher flow rate ratio has opposite effects of EP.
4C type spinneret used in hollow fiber, this method so far is an important process in hollow fiber formation. Material properties regulated by non-isothermal boundary condition influence the follow-up efficiency in application; these may due to both hollow fiber intensity and hollow percentage are uncontrolled. Furthermore, rheological properties, spinneret temperature, 4C gap, and the effects of spinning flow rate on fissure length, fissure temperature, and hollow percentage, are studied systematically. Taken together, high spinning flow rate causes the trend toward shortening fissure length and vice versa during increasing the spinneret temperature. Additionally, raising spinning flow rate helps to increase the fissure temperature leading to better viscosity. The fissure temperature of lower material viscosity is decreased; nevertheless, lower spinning flow rate needs to extend fissure length. In terms of hollow rate changes, this decrease immediately out of yarn terminal and elevates gradually after that.

並列關鍵字

Eccentric percentage ； sheath/core fibers ； viscoelasticity ； 4C type ； non-isothermal ； hollow fiber

參考文獻

[5] J. C. Slattery, S. H. Lee , “Analysis of melt spinning”, J. Non-Newtonian Fluid Mech., 89, (2000), 273-286.

[6] F. S. Mark, “Hollow fiber microfiltration membranes from poly(ether ether ketone)(PEEK)”, J. appl. Polym. Sci., 72, (1999), 175-181.

[7] M. S. Lee, S. Y. Kim, “Effects of initial structure on the deformation behavior of PP hollow fiber in continuous drawing”, J. appl. Polym. Sci., 81, (2001), 2170-2182.

[8] T. H. Oh, M. S. Lee, S. Y. Kim, H. J. Shim, “Studies on melt-spinning process of hollow fibers”, J. appl. Polym. Sci., 68, (1998), 1209-1217.

[9] J. Sun, S. Subbiah, J. M. Marchal, “Numerical analysis of nonisothermal viscoelastic melt spinning with ongoing crystallization”, J. Non-Newtonian Fluid Mech., 93, (2000), 133-151.