Theoretical Analysis of Water-Quenched Air Gap Melt Spinning and Air Gap Effect on Fiber Formation

Abstract

Theoretical and experimental studies on the dynamics of water-quenched air gap melt spinning were performed. The calculated spinning tension in the air region increases rapidly with decreasing air gap length. In particular, in the case of air gap lengths less than 2cm, high spinning tension can be obtained. It might be thought that high spinning tension during the spinning process leads to high molecular orientation of super fibers such as Aramid fibers. The maximum deformation rate in spinning processes with narrow air gaps appears at the boundary between air and water, which may be also related to the development of high molecular orientation.Draw resonance experiments were performed using air gap melt spinning on Poly (ethylene terephthalate). With decreasing air gap length, the draw resonance instability was suppressed. This might be related to the results of numerical simulation in which larger Weissenberg numbers in the draw resonance analysis for the Maxwell fluid model and higher spinning tension in the air in the case of short air gap lengths lead to the stabilization of the spinning process.