Studies on Melt Spinning

Abstract

The stability of melt spinning was analyzed by solving numerically for transients the fundamental equations of melt spinning developed by the author previously. Results were summarized in the form of stability maps in the (t*-St) plane using the cooling air speed as third parameter. Here t* is the air temperature and St is the Stanton number. An experiment was carried out in which a draw resonance was generated in a water quenched melt spinning of PET yarn. The draw resonance was subsequently surpressed by blowing a cooling air current through the air gap between spinneret and water surface.Experimental results agreed closely with simulations derived from the fundamental equations with respect to oscillation periods and stability.These findings lead to the conclusion that insufficient cooling of the thread is the primary cause of spinning instability.