Abstract: A method for melt spinning thermoplastic filament yarn is disclosed, wherein a plurality of filaments are withdrawn from a spinneret, and combined to form an advancing yarn. The advancing yarn is traversed onto a rotating bobbin to form a wound package, and the traversing speed is periodically rapidly changed so as to avoid the formation of undesirable patterns or ribbons. In addition, the advancing yarn is heated so as to lower its modulus of elasticity, so that the yarn tension and yarn denier remain within an acceptable range of variation during each change of the traversing speed.

Abstract: A method and apparatus for producing a ribbon free randomly wound yarn package is disclosed, and wherein a plurality of critical winding ratios at which undesirable pattern formations or ribbons would normally occur are determined and stored in a microprocessor control unit. During the winding operation, the spindle speed and traversing frequency are monitored by sensors and are transmitted to the control unit, and the control unit computes the optimum time for rapidly changing the traversing frequency so that the actual winding ratio moves rapidly through each of the approaching critical winding ratios. The original traversing frequency is re-established after having passed beyond each of the critical winding ratios.