Discussion of Background Art United States Patent 4,417,700 discloses an arrangement for winding yarns onto pirns in which each pirn is mounted individually on a spindle and a plurality of spindles having different lengths is required to wind a corresponding plurality of yarns.

However, this apparatus is unacceptably tall and excessively costly for winding up the many small packages typical for spandex, since each package is mounted on its own spindle. Spandex winders such as that disclosed in United States Patent 3,165,274 can be stacked one directly on top of the other. The combined spandex threadlines for both the upper and lower winders can be led through a guide at the upper winder and through the traverse guide for the upper winder before dividing the threadlines and directing one threadline to the contact roll of the upper winder and the other to the traverse guide of the lower winder.

The spandex is then wound onto tubecores to form a package. However, this arrangement results in breaks in the spandex, with resulting loss of spinning continuity and increased cost.

SUMMARY OF THE INVENTION The apparatus of the present invention for winding spandex comprises means for independently directing a first plurality spandex threadlines to an upper

winder and a second plurality of spandex threadlines to a lower winder, wherein each winder comprises: a traverse assembly for traversing the spandex along a rotatable contact roll; and a spindle for rotatably supporting, in peripheral contact with the contact roll, a plurality of tubecores onto which the spandex can be wound; the first and second plurality of threadlines being in alternate relationship to each other, and each tubecore mounted on the upper winder being axially displaced from a corresponding tubecore mounted on the lower winder by about 1/2 tubecore length.

The process of the present invention for winding spandex comprises the steps of: directing a first plurality of spandex threadlines to an upper winder; winding the first plurality of threadlines onto a corresponding first plurality of tubecores rotatably mounted on the upper winder; directing a second plurality of spandex threadlines to a lower winder; and winding the second plurality o threadlines onto a corresponding second plurality of tubecores rotatably mounted on the lower winder; wherein the first and second plurality of threadlines are in alternate relationship to each other, and wherein each tubecore mounted on the upper winder is axially displaced from a corresponding tubecore mounted on the lower winder by about 1/2 tubecore length.

A spandex package made by the process is also provided.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A illustrates the apparatus of the present invention from the side, Figure 1B from the top, and Figure 1C from the front.

Figures 2A and 2B show first and second upper guides from the top of the apparatus. Figure 2C shows upper guides from the side.

DETAILED DESCRIPTION OF THE INVENTION Spandex is a manufactured fiber in which the fiber forming substance is a long chain synthetic elastomer comprised of at least 85% by weight of a segmented polyurethane. The synthetic elastomer is generally prepared in a suitable solvent such as dimethylacetamide to form a spinning solution which is extruded through spinneret capillaries into a heated column to remove the solvent. The resulting spandex is then wound onto a tubecore by a winder at the bottom of the column.

The space at the bottom of the spinning column is usually quite limited, and making efficient use of that space, while maintaining high productivity and high package quality, is difficult. Stacking the winders atop each other can save space and afford increased productivity and final package quality without a significant sacrifice of space efficiency. Using the arrangement of this invention can also result in a reduction in breaks during spinning. The apparatus of the present invention also allowed up to 50% lower wind-up stretch, with a resulting reduction in compression within the package so that the spandex was easier to remove during use.

The means of directing the threadlines to the upper and lower winders can be a plurality of fixed guides as shown in Figure 1. The tubecores in Figure 1 are shown with some spandex lc already wound on them.

Turning first to Figure lA, the winding apparatus is seen from the side. Tubecores la mounted on spindle 2a of upper winder 3a are axially displaced from corresponding tubecores 1b mounted on spindle 2b of lower winder 3b. The displacement is about 1/2 tubecore length. Here, the winders are vertically

aligned, and the tubecore displacement is provided by spindle 2b being longer than spindle 2a, but the same result can be obtained by using spindles of substantially equal length and offsetting winder 3a from winder 3b by an appropriate distance along the orientation defined by the spindle axes. Any combination of these methods can be used to provide the necessary tubecore offset.

Upper contact roll 10a and lower contact roll lOb are mounted in such a way to permit the tubecores to be brought into peripheral contact with the appropriate contact roll. E ther the contact rolls can be freely rotating and the spindles driven, or the spindles can be freely rotatif, and the contact r311s driven, as desired.

In Figure 1A, the first upper guides are not shown; a plurality of second upper guides are shown at 5a, and a plurality of lower guides are shown at 5b.

It is preferred that lower guides 5b be self-stringing.

Optionally, the upper and lower winders can be provided with"flipper bars for directing threadlines away from the traverse guides for ease of stringup.

Eight threadlines 4 are shown in Figure 1A, corresponding to the total of eight tubecores in this illustration. The first upper guides direct the first plurality of threadlines 4a to upper winder 3a for winding on upper tubecores la. Second upper guides 5a and lower guides 5b direct second plurality of threadlines 4b past the traverse assembly (not shown) of upper winder 3a to lower winder for winding on lower tubecores lb. The first and second pluralities of threadlines are in alternating relationship to each other.

Figure lb is a top view of the apparatus of the present invention. A plurality of first upper guides 6a direct first plurality of threadlines 4a to upper traverse assembly 7a comprising traverse guide 15a, which traverses the threadlines across contact roll

10a, which in turn passes the threadlines to tubecores la. Similarly, second upper guides 5a direct alternate threadlines to lower guides, where they are traversed by a lower traverse assembly, passed around contact roll lOb, and finally wound on tubecores 1b; these threadlines, lower guides and lower traverse assembly are not seen in this top view.

Figure 1C is a front view of a pair of stacked winders 3a and 3b of the apparatus. First plurality of threadlines 4a are directed by first upper guides 6a to upper traverse assembly 7a comprising traverse guides 15a. The threadlines then pass around contact roll 10a and are wound onto tubecore la. Second plurality of threadlines 4b are directed by second upper guides 5a to lower guides 5b, which in turn direct them to lower traverse assembly 7b comprising traverse guides 15b.

The threadlines pass around contact roll 10b and are wound onto tubecores lb.

All the guides can be fixed, but it is advantageous for second upper guides 5a to be retractable to minimize snagging threadlines 4a and 4b on the second upper guides during stringup. As illustrated in Figure 2, this can be accomplished by mounting each of second upper guides 5a on a spring strip (for example of steel) which can be urged from a first position for stringup to a second position for winding.

Figure 2A shows first upper guides 6a and second upper guides 5a from the top in greater detail. In this Figure, guides 5a are in the retracted, stringup position, and are nearly in alignment with guides 6a.

In Figure 2B, guides 5a are in the running position, having been forced out of alignment with guides 6a by posts 11 mounted on handle bar 12. The handle of the bar has been turned to rotate the bar and urge the posts against steel spring strips 13. Figure 2C shows the first and second upper guides from the front of the apparatus, in the running position with second upper

guides 5a, mounted on steel strips 13, forced away from first upper guides 6a. Posts 11 are obscured by the handle of bar 12, which has been rotated to the running position. Strips 13 are fastened at one end to support 14. In this view, optional additional guides 6aa are also shown; usine these guides can improve the shape of the spandex package being wound.

Although four tubecores are shown on each spindle in the Figures, any suitable number of tubecores can be used, for example eight, twelve, sixteen, eighteen, twenty-one, twenty-four, and so on.

Traverse assemblies 7a and 7b can each comprise a cam box, a cylindrical grooved cam rotatably mounted in the box, a cam follower slidably mounted in the groove, a pair of rails ixedly mounted in the box, and a traverse guide 15 mounted on the cam follower and slidably position between the rails.