Change in Cross Sectional Shape for Hollow Filament During Winding

Abstract

Methods for obtaining hollow-fiber membranes are limited (due to the small diameter) compared with methods for obtaining other membranes. An important problem in obtaining hollow filaments by any method is development of devices for take-up of the semi-permeable hollow fibers. This is due to the specific characteristics of hollow filaments (the presence of an internal cavity). During winding of hollow filaments, loss of stability can occur under the action of radial pressure arising in the take-up from winding tension. We will consider the critical pressure to be the lowest external pressure at which the initial shape of the hollow filament cannot be recovered when the external pressure is relieved. In this work, we have analyzed the conditions for loss of stability in hollow filaments when they are obtained on equipment for building packages.