| Hollow fibers are widely used in many chemical operation's of exchange and separation, and medical application's such as hemodialysis and blood oxygenation. However, little information is available in the literature in regard to understanding of the spinning process of hollow filaments.;This research was to establish a mathematical model for the solution dry-spinning process of hollow filaments, using polyacrylonitrile (PAN)-dimethylformamide (DMF) solution as an example material; and to further utilize the model to predict the behavior of the spinline and the properties of spun hollow filaments under a variety of processing conditions.;The investigation included a theoretical modeling part and an experimental part needed to obtain appropriate input data for modeling and for comparison of the model prediction with actual experiment results. The model is based on the fundamental equations of fluid mechanics, heat and mass transfer and spinning dynamics. It includes the equations of continuity, force balance, energy balance as well as mass transfer.;A "thick walled" model was developed, which treats hollow filament as a thick walled cylinder under the triaxial stress state during spinning. A "thin walled" model was also developed on the assumption that the variation in the hoop stress with radial position in the filament could be neglected. |
