Method of making spun yarn packages multiple individually separable yarn ends

#The present invention generally relates to the field of synthetic filament production. In its preferred form, the present invention relates to the production of melt-spun yarns which am helically wound to form a generally cylindrical yarn package.

#Yarns composed of multiple filaments are traditionally produced by melt-spinning techniques whereby a melt-spinnable polymer is extruded through relatively small-sized orifices in a spin pack to form a stream of filaments which are substantially immediately solidified in a quench cabinet and converged after solidification to form a yarn composed of multiple filaments. The yarn is thereafter continuously taken up by a high speed winder to form a generally cylindrical yarn package. Depending on the intended end use, the yarn may be flat (undrawn) or may be subjected to a drawing step prior to being taken up to form the package.

#During take-up, the yarn end is guided through a traversing arm associated with the high speed winder. The traversing arm reciprocates at relatively high speed linearly parallel to the longitudinal axis of a rotating yarn package core. As a result, the traversing arm causes the yarn end guided thereby to be wound in alternating layers of reverse helical directions about the core as the yarn package is "built" (i.e., as the radial dimension of the yarn package increases due to the yarn end being wound thereabout in alternating reverse helical layers).

#Reference will hereinafter be made to the accompanying drawings wherein like reference numerals throughout the various FIGURES denote like structural elements, and wherein;

#FIG. 1 is a schematic front elevational view of a yarn spinning and winding system according to the present invention;

#FIG. 2 is a schematic side elevational view of a high speed winder that is employed in the system depicted in FIG. 1; and

#An exemplary spinning apparatus 10 for making melt-spun synthetic filaments is depicted schematically in accompanying FIG. 1. As shown, the yarn spinning apparatus 10 generally includes a polymer extruder 12 which melts and blends a melt-spinnable polymer (e.g., nylons such as nylon-6 and nylon-6,6, polyesters, and polyolefines such as polypropylene) and feeds a flow of the polymer melt to a spin pack 14. The spin pack is conventional in that it includes a plurality of grouped orifices through which the polymer melt is forced so as to form a corresponding plurality of yarn ends 16a-16f. In this regard, each of the yarn ends 16a-16f itself includes a plurality of individual filaments corresponding in number to the number of orifices in an orifice grouping within the spin pack 14. Furthermore, six yarn ends 16a-16f each composed of multiple (e.g., preferably six to twelve or more) individual filaments just happen to be depicted in FIG. 1. Thus, more or less than the depicted six yarn ends 16a-16f may be present for any given melt spinning apparatus 10.

#The individual filaments forming the yarn ends 16a-16f quickly solidify within the quench cabinet 18 downstream of the spin pack 14 and are brought into contact with a spin finish applicator 19 where a liquid finish oil is applied to the filaments to improve subsequent filament processing. The yarn ends 16a-16f are then passed through a conventional filament interlacer 20 which serves to increase the filament-to-filament cohesion between the individual filaments in each of the yarn ends 16a-16f. In this regard, it is preferred that the filament interlacer 20 be supplied with a pressurized fluid (e.g., air, steam, nitrogen or the like) which is brought to bear against each of the yarn ends 16a-16f within the interlacer 20 so as to cause the individual filaments of each yarn end 16a-16f to become intimately commingled with one another. It will be understood, however, that the yarn ends 16a-16f are not commingled with one another within the interlacer 20, but instead exit the interlacer 20 as coherent individually identifiable yarn ends.

#Multiple ones of the yarn ends 16a-16f are then converged at the notched convergence bar 22 to form yarn end ribbons 24a-24c, respectively. In the embodiment shown, yam ends 16a and 16b are converged with one another to form yarn end ribbon 24a, while yarn ends 16c, 16d and 16e, 16f are converged to form yarn end ribbons 24b and 24c, respectively. Thus, in the embodiment shown, each of the yarn end ribbons 24a-24c will be comprised of a pair of the yarn ends 16a-16f. However, more than a pair of such yarn ends 16a-16f may be converged, in which case a lesser number of yarn end ribbons will be formed. Thus, for example, three of the yarn ends 16a-16f may be converged to form two yarn end ribbons.