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

• Main Authors: Cheng-Yan Tsai, 蔡政諺
• Other Authors: Yuan-Yuan Su
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/x9448w

碩士 === 國立臺北科技大學 === 化學工程研究所 === 98 === 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.