Abstract: A method for melt spinning thermoplastic filament yarn is disclosed, wherein a plurality of filaments are withdrawn from a spinneret, and combined to form an advancing yarn.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: The invention provides an improved method for winding synthetic yarns and wherein the yarn is wound about a core at a substantially constant rate while the yarn is guided onto the core by a traversing yarn guide. The speed of the traversing yarn guide is proportional to the rotation of the package to define a substantially constant winding ratio during a series of sequential steps, and the speed of the traversing yarn guide is rapidly increased at the beginning of each of the sequential steps to produce a stepped precision wind. The upper and lower values of the traversing speed are both changed in a predetermined manner during the winding cycle, and so as to form a cylindrical package without harmful yarn patterns or bulges.