Effect of Heat Transfer Coefficient on the Temperature Gradient for Hollow Fiber

The heat transfer coefficient h caused by blowing affects the heat transfer of fiber greatly. Especially, unsymmetrical blowing forms the unsymmetrical temperature gradient on the fiber cross-section. Based on the results of spuming simulation by computer, the changes of heat transfer coefficient on the cross-section along the spinning line and the effects on distributions of temperature gradients were discussed. It is showed that for the spuming simulation of hollow fiber under strong blowing condition, the heat transfer coefficient should be modified as :     

Computer Simulation of Unsymmetry of the Melt - spinning Hollow Fiber

Unsymmetrial cooling always exists in melt - spinning process with circle blowing or lateral blowing cooling, especially for hollow fiber. In melt spinning processes, due to this unsymmetrical cooling, the thermal conductivity is different in each direction. It is certain that in these regions the unsymmetrical structure is formed. In this paper, the computer simulation of unsymmetrical cooling in melt spinning system is researched. The results show that the maximum temperature difference is up to45℃. The point of the highest temperature is not in the center of fiber but near to lower thermal conductivity side. The throughput affects the formation along the spinning line and at lateral direction. The take - up velocity affects the axial formation but affects the lateral structure little.