Tube cores for packaging elastomeric filaments

This application claims benefit of priority from Provisional Application No. 60/971,428, filed Sep. 11, 2007. This application hereby incorporates by reference Provisional Application No. 60/971,428 in its entirety.

1. Field of the Invention

The present invention generally relates to tube cores for winding of thread/fiber/yam into packages, and more particularly to improved paper tube cores for winding elastomeric fibers, such spandex thread/fiber/yam, and the like, into packages for subsequent use in continuous running over-end-take-off (OETO) applications.

2. Discussion of the Background

Textile yam tube cores are employed in the textile industry for winding and supporting yam packages. Modem high speed yarn manufacturing processes typically employ an automated system that winds the yarn onto a tube core to a specified package size. Once full package size is achieved, the fully wound tube core is automatically moved out of position, while an empty tube core is simultaneously moved from an idle position to the winding position, where the winding of a new package is initiated on the empty tube core. This type of winding operation may be carried out on a turret-type winder known in the textile industry. For example, a take-up winder may be employed, which can switch two tube core holders between a winding position and a standby position by rotating a turret. The tube core in the winding position is rotationally driven, such that the moving threadline exiting a fiber manufacturing process in tangential contact with the tube core is wound onto the core. A traverse device traveling parallel to the axis of the tube core moves the threadline back and forth along the length of the tube core so that the package is evenly built as winding proceeds. A contact roll in contact with the outer periphery of the building package senses when the radial dimension of the wound package has reached its specified full size. At that time, the turret rotates bringing the empty standby tube core into the winding position. The moving threadline is engaged with the empty rotating tube core to begin the winding of a fresh package while simultaneously the threadline between the completed package, rotated to the standby position, and the new package is cut. The completed package is removed from the standby position and replaced with an empty tube core.

Over-end-take-off (OETO) delivery of fiber or yarn from a package produced, as described above, is often preferred to rolling take-off, especially with certain elastomeric fibers, such as spandex, and the like. FIG. 1 illustrates an exemplary OETO apparatus 100 having a plurality of packages 102 for OETO delivery (e.g., as further described in commonly-assigned U.S. Pat. No. 6,676,054, U.S. Published Patent Application Nos. 2005/0133653 A1, and 2006/0011771 A1, and PCT Published Patent Application No. WO2006/025955, incorporated by reference herein). One advantage of OETO is that the package remains stationary during unwinding and therefore allows continuous operation of a manufacturing process, because the terminating end (referred to as the “transfer tail”) of the fiber wound on an active package can be attached to the leading end of the fiber wound on a standby package.

Various methods have been reported for forming a transfer tail as the winding of a package begins, such that the transfer tail can be easily located and separated from the package, when the fiber is to be subsequently unwound so that it may be fed to some manufacturing process.

Methods for forming an accessible transfer tail have included providing the surface of the tube core with a slip resistant coating. Several rotations of the tube core prior to starting the traverse mechanism will form a transfer tail wound in a location near the edge of one end of the tube core and displaced from that region of the tube core on which the remainder of the packaging will be built once the traverse mechanism is started. The slip resistant coating aids in preventing sliding of the transfer tail along the surface of the tube core so as to become entrapped under the building package. The slip resistant coating also is effective in preventing movement, parallel to the axis of rotation of the tube core, of the first several winds of yarn that are laid down in the traverse region.

Another method reported for producing useable transfer tails is to provide a circumferential groove or recess in the outer surface of a tube core and located near one end of the tube core and displaced from that region of the tube core on which the remainder of the packaging will be built once the traverse mechanism is started. The groove also helps prevent movement of the transfer tail that might render it unusable.

It is known to use colloidal silica, which changes the surface friction between yarn and the tube core used to wind the yarn, to improve the yarn release characteristics. U.S. Pat. No. 4,057,201, entitled “Yarn Core Including Slip Resistant Transfer Coating,” discloses a method which was used to treat tube cores to increase the coefficient of friction.

It is known to use a groove or slot in a tube core, which facilitates the transfer tail formation process. U.S. Pat. No. 5,441,208, entitled “Textile Core Having Transfer Tail Engagement,” discloses a design of a groove which was used to increase gripping of yarn.

However, as provided in the prior art, a tube core with a 360 degree groove cut, and a smooth surface, does not provide the best groove and surface characteristics for the production of wound spandex packages and the unwinding of such packages to provide continuous delivery of elastomeric fibers, such spandex thread/fiber/yarn, and the like, via OETO technology, and the like, in one cohesive design.

OETO delivery of fiber to a manufacturing process may still experience process interruptions even if the transfer tail formation and recovery has been successful. When initiating the winding of a new package, the length of fiber between the transfer tail winds and the cut that was made to sever the threadline from the previously completed package may become embedded underneath the building package. If long enough, it may even wrap itself around the tube core underneath the package to be wound. During the unwinding process, such defects can result in the last few layers of a nearly exhausted package to separate from the tube core all at once (e.g., in a clump), leading to a fouling of the threadline and possible process interruption.

Therefore, there is a need for a tube core that does not suffer from the above and other deficiencies of prior tube cores and so as to improve consistency of transfer tail formation and to ensure efficient and continuous over-end-take-off (OETO) yarn delivery performance for elastomeric fiber (e.g., spandex, and the like) producers, customers in the hygiene industry, and the like. The above and other problems are addressed by the exemplary embodiments of the present invention, which provide ideal tube core characteristics for the winding and subsequent unwinding of elastomeric fiber (e.g., spandex, and the like), for example, as follows.

An exemplary cylindrical tube core is provided that combines (1) a non-continuous circumferential groove or recessed channel traversing less than 360° of the tube core circumference, for example, having a depth less than the thickness of the tube core wall, oriented perpendicular to the axis of the tube core, and located near one end of the tube core; and (2) a slip resistant outer surface. Thus, the non-continuous groove or recessed channel is formed in the outer wall of the tube core and located proximate to one end of the tube core, with a slip-resistant coating or surface on the outer wall of the tube core. The non-continuous groove or channel, aligned perpendicular to the axis of rotation of the tube core and proximate to one end of the tube core, traverses a total of less than 360° and in the range of 180° to 355° of the circumference of the outer wall of the tube body. The less than 360° angular range covered by the groove can be in one uninterrupted segment. Alternatively, the less than 360° groove can include alternating segments of grooved and non-grooved surface aligned in a single circumferential line proximate to one end of the tube core such that cumulative angular range traversed by the grooved segments is less than 360°. The exemplary features respectively promote the formation of a well defined transfer tail that can be easily located and captured and the avoidance of yarn slippage/entanglement at the tube core when the last winds of yam are removed. The non-continuous groove anchors the fiber of the transfer tail below the outer wall surface of the tube core around most of the tube core circumference, but leaves a circumferential segment or segments where the transfer tail is lying on top of the outer wall of the tube core, and advantageously, avoiding the problem of having to extract the transfer tail from the recessed groove.

Accordingly, in exemplary aspects of the present invention there is provided a tube core for production and delivery of elastomeric filaments, including a tube body, a non-continuous groove or recessed channel formed in an outer wall of and proximate to one end of the tube body, and a slip-resistant coating or surface on the outer wall of the tube body. The total angular range traversed by the groove or channel is less than 360° or in the range of 180° to 355° of the circumference of the outer wall of the tube body. The slip-resistant coating or surface includes a colloidal silica, such as a Ludox®, coating or surface. The tube body is constructed from paper. The elastomeric filaments include spandex. The tube core is adapted for over-end-take-off (OETO) applications.

Advantageously, the improved tube core of the exemplary embodiments provides for improved transfer tail formation efficiency during production of a wound package and ease of capturing the transfer tail when preparing for unwinding. The latter is advantageous when mounting the package on an unwinding creel and splicing the transfer tail to the leading yam end of a standby package to ensure continuous, reliable unwinding performance at the customer. The exemplary embodiments thus provide the dimensions and placement of a groove cut into the tube for the purpose of receiving the transfer tail during winding, and the slip resistant character of the tube surface, advantageously, resulting in more efficient transfer tail formation on, and removal from, the wound elastomeric fiber (e.g., spandex thread/fiber/yarn, and the like) package, as well as more reliable yam delivery from the tube surface during the unwinding of the package.

Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, by illustrating a number of exemplary embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention is also capable of other and different embodiments, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive.