Patent Publication Number: US-2005139724-A1

Title: Reusable yarn tube

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority to co-pending U.S. Provisional Patent Application No. 60/527,935, filed Dec. 8, 2003, which is incorporated herein in its entirety. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates to a yarn tube that is reusable. Embodiments of the present invention provide a reusable yarn tube useful for preventing yarn snags on defects in and about the ends of the tube.  
     BACKGROUND OF THE INVENTION  
      A yarn tube is a holder or bobbin of cylindrical shape used as a core for a “yarn package” from which the yarn can be easily unwound for use in knitting, weaving, and other processes. As such, yarn tubes are used in textile manufacturing for providing yarn to a knitting or other machine for processing the yarn. During a knitting or weaving process, yarn is unwound from a tube along the longitudinal axis of the tube such that the yarn moves across the end of the tube as it is unwound. Yarn used in textile manufacturing can be extremely fine, for example, low denier nylon yarns used in fashion hosiery production, and is thus highly susceptible to snagging on unsmooth surfaces. It is important that the end of a yarn tube be smooth so that yarn, particularly fine yarn, is not snagged or picked by imperfections in the tube end as the yarn moves across the tube end at high speed to needles in a knitting machine.  
      Conventional yarn tubes are often made of laminated cardboard and/or similar materials. When yarn is completely unwound from a tube, the tube is removed from a textile manufacturing machine, such as a knitting or weaving machine. During the tube removal process, and at other times, tubes may be handled without attention to protecting the surface integrity of the tube ends. At times, tubes are tossed into a container and may be dropped, causing imperfections, such as nicks or “burrs” in the tube ends. If a damaged tube is then reused at high manufacturing speeds, such damage can even lead to delamination of the tube. As a result of these burrs, yarn tubes would not be suitable for re-use, because such burrs would cause yarn fed across the tube end to snag or even break. When yarn snags on a tube burr, the quality of the yarn in the knitted product may be less than desirable. Importantly, when yarn fed from a tube snags on a burr, the knitting operation often must be stopped, and a worker must repair the yarn feed into the knitting machine. Such disruption in automated, high-speed knitting processes causes increased labor and manufacturing time, adding to the cost of production. Moreover, when yarn being fed to a knitting machine snags on a tube end burr, the worker may determine that the tube is unusable and discard the tube along with the remaining yarn on the tube. Consequently, yarn tube end burrs can cause loss of significant amounts of yarn. As a result, conventional paper winding tubes are generally not reusable.  
      Yarn manufacturers and textile manufacturers use millions of yarn tubes each year. Conventional paper tubes are relatively expensive (50 cents to $1.00 each). Thus the cost of non-reusable yarn carriers is extremely high. Providing a means for reliably and inexpensively overcoming burrs in tube ends in order to make yarn tubes reusable would save much of the annual cost of yarn tubes. In view of the negative cost and manufacturing consequences associated with yarn tube end defects, it is desirable to provide yarn tubes having ends that resist development of burrs from use during the knitting or weaving process and/or from handling before and after use.  
      Various attempts have been made to develop reusable yarn tubes, including modifications to the starting groove and/or starting groove end of a tube. One end of a conventional cylindrical, laminated paper tube includes a starting groove, often an annular groove, cut, or otherwise recessed, into the outer surface near one end of the tube. The starting groove includes a means for “leading in” and locking an initial strand of yarn. During the initial few turns of an automatic winding operation, yarn is wound onto the starting groove. The initial strands of yarn placed in the starting groove are commonly referred to as the “waste bunch.” After a tube has a pre-determined length of yarn wound onto the tube surface, the completed “yarn package” is removed from the winding machine such that the yarn can be further processed, for example, by weaving, knitting, or texturing.  
      One attempt to modify a yarn tube for reuse at least once involved providing a starting groove at each end of the tube. However, paper tubes are often damaged during the automatic placement and removal of the tubes on and off tube mounts. Consequently, using a damaged starting groove end of a tube for unwinding yarn substantially eliminates even a single reuse of the paper tubes.  
      Attempts have also been made to construct yarn tubes having reusable starting groove ends. For example, U.S. Pat. No. 4,901,941 to Powel et al. discloses an end cap and a slidable ring releasably mounted on the end of a yarn tube to form a reusable yarn carrier or winding tube. The opposing walls of the end cap and ring define a starting groove therebetween. When the yarn carrier has been emptied, the end cap and ring are separated from the tube, the residual yarn is removed, and the end cap and ring are replaced on the tube for reuse. The Powell et al. patent is directed to winding tubes in which a yarn transfer tail (or waste bunch) is easily severed and removed from the starting groove once the yarn package has been emptied. However, this patent does not address the reusablility of yarn tubes with respect to providing a smooth surface over burrs and snags in the non-starting groove end of a tube.  
      U.S. Pat. No. 6,073,868 to Stevens et al. discloses a re-usable, cylindrical yarn carrier preferably made of a plastic material, each end of which has a channel. A resilient ring positioned within each channel forms a yarn winding engagement surface. The ring also serves as a protective edge, such that, if the tube is dropped, the ring takes the brunt of the force rather than the tube material itself. Such tubes of polymeric materials alone are undesirable, as they will not withstand conventional winding speeds because of their tendency to develop “creep” and/or to expand at such speeds; they do not provide a thickness suitable for molding or machining a satisfactory starting groove; they are prohibitively expensive to manufacture; and they do not provide a means for a reusably smooth surface over which yarn can be unwound from a tube.  
      In another attempt to provide a reusable yarn tube, various coatings were applied to used tubes by “hot-dipping” the tubes into the coatings. However, tube ends having a surface smooth enough to prevent snags of yarn were not produced by these attempts.  
      Thus, there is a need to provide yarn tubes that have ends that reliably prevent yarn snags in defects in and about the tube ends and are thus reusable. There is also a need for reusable yarn tubes having ends that resist development of burrs from use during a knitting or weaving process and/or from handling before and after use in such processes. There is also a need to provide such reusable yarn tubes that can be made easily and inexpensively.  
     SUMMARY OF THE INVENTION  
      The present invention provides a yarn tube, or bobbin, that is reusable. Embodiments include a reusable yarn tube useful for preventing yarn snags on defects in and about the ends of the tube.  
      In an embodiment of the present invention, a reusable yarn tube comprises a hollow tube having a substantially cylindrical wall, opposite ends, and an outer surface adapted to carry a yarn on the tube surface. The tube includes a starting groove in the outer surface proximate one end of the tube. A pre-formed sleeve having a smooth surface is form-fitted about a portion of the outer surface of the tube and the end of the tube opposite the starting groove end, also referred to as the yarn-unwinding end. In this manner, the sleeve provides a smooth surface for the yarn to be wound onto and unwound from the tube. In preferred embodiments, the sleeve is fitted about the yarn-unwinding end of the tube and across the thickness of the cylindrical wall without contacting the inside surface of the tube.  
      In embodiments of the present invention, a pre-formed sleeve, such as a plastic sleeve, is placed onto a tube over a portion of the tube proximate to the yarn-unwinding end such that the sleeve extends a pre-determined distance beyond the tube end. The sleeve is adaptable to be form-fitted about a portion of the tube and the end of the tube. In a preferred embodiment, the sleeve is capable of being set into a desired form about the tube end by application of heat. In such an embodiment, the tube and sleeve are exposed to heat, such as in a heat tunnel, and the sleeve is heat-shrunk, or thermoset, to form fit about the tube end.  
      In preferred embodiments, the distance that the sleeve extends beyond the tube end prior to thermosetting is such that when the sleeve is form-fitted about the tube and tube end, the distal edge of the sleeve (the edge extending beyond the tube end) is located a distance, for example {fraction (1/16)} inch, just short of the inside surface of the tube. Positioning the sleeve a distance just short of the inside surface of the tube avoids contact of the sleeve with a creel and thus avoids potential problems associated with such contact, such as interference with movement of the tube on the creel and damaging the sleeve. A sleeve that is damaged, such as by cracking when hit against a creel, can undesirably create imperfections or burrs in the tube end that can cause yarn to snag. Thus, positioning a sleeve so as to avoid contact with a creel protects the integrity of the sleeve and maintains the sleeve in a condition suitable for providing a smooth surface over which yarn can be unwound.  
      The distance the form-fitted sleeve extends along the outer surface of the tube from the tube end is sufficient to cover the portion of the tube over which yarn would travel as it is unwound from the tube and fed to a knitting or weaving machine. As such, the sleeve would allow yarn from the tube to travel over a smooth surface as it is fed to a knitting or weaving machine and thereby avoid snagging burrs or other imperfections in the tube near the tube end or in the tube end itself.  
      A sleeve of the present invention comprises a material capable of being form-fitted, such as thermoset, about a tube end: In preferred embodiments, the sleeve is slidably formed about a tube end such that after the sleeve is form-fitted onto the tube end, the sleeve can be removed from the tube by sliding it in a direction along the tube longitudinal axis away from the tube. Preferably, such a sleeve comprises polyvinyl chloride (PVC). When such a removable sleeve begins to show wear from repeated use, the sleeve can be easily slid off of the tube and replaced with another sleeve. In this manner, the same tube can be reused beyond the effective life of a single sleeve.  
      In embodiments of the present invention, a sleeve comprises a thickness and a composition adapted to withstand pressure from yarn wound thereon and from the stress of spinning on a tube mount. In addition, a sleeve of the present invention preferably comprises a composition adapted to avoid absorption of moisture and oils from the yarn wound thereon and from the tube itself. In a preferred embodiment, a sleeve comprises a 3 ml thick PVC plastic, which is capable of both withstanding the stress from yarn winding and spinning and avoiding absorption of moisture and oils. Such a sleeve is thus able to maintain its smooth surface integrity and avoid cracks or burrs that may cause yarn snags.  
      Embodiments of the present invention provide an identification means for distinguishing the yarn to be wound on the outer tube surface. The outer surfaces of yarn tubes often include one or more colors, either as a solid color, in stripes, or in another pattern. Tubes are made having different color schemes that can be used to identify a particular yarn type. In embodiments of the present invention, reusable yarn tubes include sleeves comprising a particular color that can be used to represent a particular type of yarn wound onto the tube. As a result, yarn tubes could have the same color, and colored sleeves could be to identify the yarn type, thus saving the added cost of having smaller quantities of tubes made in different colors.  
      In embodiments of the present invention, reusable tubes comprise paper, which can be wound in a spiral or convolute pattern. Tubes may comprise other materials suitable for yarn tubes, including steel, aluminum, metallic alloys, and fiber reinforced polymeric materials.  
      Embodiments of the present invention include yarn tubes having various dimensions, including various lengths, diameters, and wall thicknesses. Sleeves are preformed to fit the dimensions of the tubes for which they are intended.  
      Another aspect of the present invention includes methods of making a reusable yarn tube. An embodiment of such a method includes first providing a hollow tube having a substantially cylindrical wall, an outer surface adapted to carry a yarn thereon, a starting groove in the outer surface proximate one end of the tube, and an opposite, yarn-unwinding end. A pre-formed sleeve having a smooth surface is fitted about a portion of the outer surface of the yarn-unwinding end. The sleeve is formed about the yarn-unwinding end of the tube so that the sleeve provides a smooth surface for the yarn to be wound onto and unwound from the tube.  
      In an embodiment of such a method, fitting the sleeve about the yarn-unwinding end of the tube includes extending the sleeve a distance beyond the yarn-unwinding end such that when the sleeve is formed about the yarn-unwinding end, the sleeve extends across the thickness of the cylindrical wall of the tube without contacting the inside surface of the tube.  
      In preferred embodiments, methods of the present invention include placing the yarn-unwinding end of the tube having the sleeve fitted thereabout onto a sleeve-forming mold. The mold has a substantially cylindrical outer surface having an outside diameter sized to fittingly receive the tube. The mold further includes a ring projecting outwardly from its outer surface for supporting the tube when the tube is placed onto the mold.  
      In embodiments, the ring has a thickness projecting outwardly from the outer surface of the mold such that the distal edge of the sleeve (extending beyond the tube end) will not contact the ring when the sleeve is formed about the tube and tube end. Accordingly, the outwardly projecting thickness of the mold ring is less than the distance from the inside surface of the tube that the distal edge of the sleeve is located when the sleeve is formed about the tube and tube end. As such, the sleeve will not contact the ring during the form-fitting process, and avoid having its movement interfered by the ring or becoming attached to the ring.  
      In addition, embodiments include a mold, the bottom of which is spaced a distance from the surface below the mold, for example, a mold support base. The distance the bottom of the mold is spaced above the surface below is sufficient for the portion of the sleeve extending beyond the end of the tube to clear the surface below the mold. This clearance distance allows the portion of the sleeve extending beyond the end of the tube to move freely (and not contact the surface below) during the form-fitting process. As such, the sleeve avoids interference by, or attachment to, the surface below.  
      In embodiments of methods of the present invention, fitting the sleeve about an end of the tube includes expanding the sleeve with a cup device and placing the cup device and expanded sleeve onto the yarn-unwinding end of the tube.  
      In preferred embodiments of the present invention, the sleeve is thermosettable, such that the sleeve can be formed about an end of the tube by application of a pre-determined level of heat for a prescribed amount of time sufficient to form the sleeve about the tube end. For example, a sleeve can be formed about a paper yarn tube end by heating a sleeve-forming mold supporting the yarn tube and pre-formed, polyvinyl chloride (PVC) sleeve fitted about the tube end in a heat tunnel. The mold-tube-sleeve assembly is subjected to a temperature and for a period of time sufficient to form the sleeve about the outer surface of the tube and the tube end such that the sleeve is slidably removable from the tube. During the process of preparing yarn tubes for placement into, for example, a heat tunnel, the tubes can be inspected for burrs or other defects.  
      Methods of making a reusable yarn tube of the present invention provide embodiments that include automated processes. For example, computer-based logic, mechanisms, and devices can be applied to such processes in order to automatically make a reusable yarn tube of the present invention.  
      Features of a reusable yarn tube of the present invention may be accomplished singularly, or in combination, in one or more of the embodiments of the present invention. As will be appreciated by those of ordinary skill in the art, the present invention has wide utility in a number of applications as illustrated by the variety of features and advantages discussed below.  
      A reusable yarn tube of the present invention provides numerous advantages over prior yarn tubes. For example, the present invention advantageously provides yarn tubes that are reusable, thereby decreasing the cost of purchasing one-time-use yarn tubes.  
      Another advantage is that the present invention provides a reusable yarn tube that decreases down time during knitting operations due to yarn snags on tube end burrs.  
      Another advantage is that the present invention provides a reusable yarn tube that prevents waste of yarn due to disposal of a tube with unused yarn after a yarn snag occurs on tube end burrs during a knitting operation.  
      Another advantage is that the present invention provides a reusable yarn tube that can be easily made, for example, by using a conventional heat tunnel.  
      Another advantage is that the present invention provides a reusable yarn tube that can be inexpensively made, for example, by utilizing conventional heat tunnels to form a sleeve about a tube end. Plastic sleeves of the present invention can be produced commercially for a cost in the range of 1-1.5 cents per sleeve.  
      Another advantage is that the present invention provides a reusable yarn tube including a sleeve that is removably slidable about a tube end such that after the sleeve has been utilized for its useful life, it can be removed and another sleeve applied. As such, tubes of the present invention can be utilized repeatedly, beyond the useful life of a single sleeve.  
      Another advantage is that the present invention provides a reusable yarn tube including a sleeve having a thickness and a composition adapted to withstand pressure from yarn wound thereon and from the stress of spinning on a tube mount. In addition, such sleeves have a composition adapted to avoid absorption of moisture and oils from the yarn wound thereon and from the tube itself. Consequently, the effective useful life of yarn tubes can be further extended.  
      Another advantage is that the present invention provides sleeves having a particular color that can be used to represent a particular type of yarn wound onto a tube. As a result, a textile manufacturer could purchase all yarn tubes having the same color and save the cost of having multiple smaller portions of tubes made in different colors.  
      As will be realized by those of skill in the art, many different embodiments of a reusable yarn tube according to the present invention are possible. Additional uses, objects, advantages, and novel features of the invention are set forth in the detailed description that follows and will become more apparent to those skilled in the art upon examination of the following or by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side view of a reusable yarn tube having a sleeve formed about an end of the tube in an embodiment of the present invention.  
       FIG. 2  is a view of a smooth, plastic sleeve useful in an embodiment of the present invention, as shown in  FIG. 1 .  
       FIG. 3  is a view of a reusable yarn tube showing a sleeve formed about an end of the tube and yarn wound onto the tube in an embodiment of the present invention.  
       FIG. 4  is a perspective view of the end of a yarn tube having a sleeve fitted about a portion of the outer surface of the tube and extending a distance beyond the tube end in an embodiment of the present invention.  
       FIG. 5  is a perspective view of the end of a yarn tube having a sleeve formed thereabout in an embodiment of the present invention.  
       FIG. 6  is a perspective view of a sleeve-forming mold useful in an embodiment of the present invention.  
       FIG. 7  is a view of a reusable yarn tube having a sleeve formed about an end of the tube and supported on a sleeve-forming mold in an embodiment of the present invention.  
       FIG. 8  is diagrammatic chart illustrating the steps in an embodiment of a method of the present invention. 
    
    
     DETAILED DESCRIPTION  
      The present invention provides a yarn tube that is reusable. Embodiments include a reusable yarn tube useful for preventing yarn snags on defects in and about the ends of the tube.  FIGS. 1-8  illustrate such embodiments.  
      In an embodiment of the present invention, as shown in  FIGS. 1-5 , a reusable yarn tube  10  comprises a hollow tube  11  having a substantially cylindrical wall  12 , and an outer surface  14  adapted to carry a yarn  20  on the tube outer surface  14 . The tube  10  includes a starting groove  16  in the outer surface  14  proximate one end of the tube  10 . The starting groove  16  provides a means for yarn  20  to connect to the tube  10  so that the yarn  20  can be wound onto the tube  10 . The end of the tube  10  near the starting groove  16  is a starting groove end  17 , and the opposite end of the tube  10  is a yarn-unwinding end  18 . A pre-formed sleeve  30  having a smooth surface  31  is fitted about a portion  15  of the outer surface  14  of the tube  10  and an end  17 ,  18  of the tube  10 . In this manner, the sleeve  30  provides a smooth surface  31  for the yarn  20  to be wound onto and unwound from the tube  10 . In preferred embodiments, the sleeve  30  is fitted about the yarn-unwinding end  18  opposite the starting groove end  17 , and across the thickness (t 1 )  13  of the tube  10  cylindrical wall  12  without contacting the inside surface  19  of the tube  10 .  
      Generally, the term “tube end” refers to the surface along the thickness (t 1 )  13  of a tube wall  12  between the inside surface  19  and the outer (outside) surface  14  of the tube  10 . Where reference is made herein to the outer surface  14  of a tube  10  near a tube end together with the surface along the thickness (t 1 )  13  of the tube wall  12  as being the portion of the tube about  10  which a sleeve  30  is fitted, “tube end” refers to both structures  13 ,  14 .  
      In embodiments of the present invention, a pre-formed sleeve  30 , such as a plastic sleeve, is placed onto a tube  10  over a portion  15  of the tube  10  proximate to the yarn-unwinding end  18  such that the sleeve  30  extends a pre-determined distance (d 1 )  32  beyond the tube end  18 . The sleeve  30  is adaptable to be form-fitted about a portion  15  of the tube  10  and the end  18  of the tube  10 . In a preferred embodiment, the sleeve  30  is capable of being set into a desired form about the tube end  18  by application of heat (as discussed below). In such an embodiment, the tube  10  and sleeve  30  are exposed to heat, such as in a heat tunnel (not shown), and the sleeve  30  is heat-shrunk, or thermoset, to form fit about the tube end  18 .  
      In preferred embodiments (as shown in  FIGS. 2, 4 , and  5 ), the distance (d 1 )  32  that the sleeve  30  extends beyond the tube end  18  prior to thermosetting is such that when the plastic sleeve  30  is thermoset to form fit about the tube  10  and tube end  18 , the distal edge  33  of the sleeve (the edge extending beyond the tube end  18 ) is located a distance (d 2 )  34  ( FIG. 5 ) just short of the inside surface  19  of the tube  10 . For example, for a tube  10  having a wall thickness (t 1 )  13  of ⅜ inch, the sleeve  30  is positioned to extend {fraction (5/16)} inch beyond the tube end  18  so that when the sleeve  30  is heated to form fit the tube  10  and tube end  18 , the distal edge  33  of the sleeve  30  is located {fraction (1/16)} inch from the inside surface  19  of the tube  10 . Positioning the sleeve  30  a distance (d 2 )  34  just short of the inside surface  19  of the tube  10  avoids contact of the sleeve  30  with a creel (not shown), or other spool rack, as the tube  10  is placed onto the creel and while the tube  10  spins on the creel as yarn  20  is wound onto the tube  10  and subsequently unwound from the tube  10 . Preventing contact of the sleeve  30  with a creel avoids potential problems associated with such contact, such as interference with movement of the tube  10  on the creel and damaging the sleeve  30 . A sleeve  30  that is damaged, such as by cracking when hit against a creel, can develop more extensive cracks as yarn  20  is wound onto and unwound from the tube  10 . Such cracks in a sleeve  30  can undesirably create imperfections or burrs in the tube end  18  that can cause yarn to snag. Thus, positioning a sleeve  30  so as to avoid contact with a creel protects the integrity of the sleeve  30  and maintains the sleeve  30  in a condition suitable for providing a smooth surface  31  over which yarn  20  can be unwound.  
      The distance (d 3 )  35  the heat-shrunk, form-fitted sleeve  30  extends along the outer surface  14  of the tube  10  from the tube end  18  is sufficient to cover the portion of the tube over which yarn  20  would travel as it is unwound from the tube  10  and fed to a knitting or weaving machine. For example, for a tube  10  having a length  21  of about nine inches, a sleeve  30  would extend approximately one and one half to two inches from the tube end  18  in the direction of the longitudinal axis  22  and along the outer surface  14  of the tube  10 . Accordingly, the sleeve  30  would allow yarn  20  from the tube  10  to travel over a smooth surface  31  as it is fed to a knitting or weaving machine and thereby avoid snagging burrs or other imperfections in the tube  10  near the tube end  18  or in the tube end  18  itself.  
      A sleeve  30  of the present invention comprises a material capable of being form-fitted, such as thermoset, about a tube end  17 ,  18 . In preferred embodiments, the sleeve  30  is formed to be slidably removable about a tube end  17 ,  18  such that after the sleeve  30  is thermoset onto the tube end  17 ,  18 , the sleeve  30  can be removed from the tube  10  by sliding it in a direction along the tube longitudinal axis  22  away from the tube  10 . Preferably, such a sleeve  30  comprises polyvinyl chloride (PVC).  
      In operation, when a sleeve  30  begins to show wear from repeated use, the sleeve  30  can be easily slid off of the tube  10  and replaced with another sleeve  30 . In this manner, the same tube  10  can be reused an even greater number of times, for example, until the tube  10  begins to show interruptions in structural integrity other than burrs in the tube end  17 ,  18  (such as warping of the tube  10 ). Thus, tubes  10  of the present invention can be utilized repeatedly, beyond the useful life of a single sleeve  30 .  
      In embodiments of the present invention, a sleeve comprises a thickness (t 2 )  37  (as shown in  FIG. 2 ) and a composition adapted to withstand pressure from yarn  20  wound thereon and from the stress of spinning on a tube mount. To be reliable on modern winding and yarn processing machinery, yarn tube  10  constructions are required which will resist the stress loads, particularly tensile, or “hoop,” stress, imposed at winding speeds in excess of 18,000-20,000 revolutions per minute (RPM). Further, it is desirable that yarn tubes  10  maintain the same effective outer diameter and inner diameter during repeated use, so as to be compatible with drive rolls and mounting spindles of yarn winding and processing machinery. In a preferred embodiment of the present invention, a sleeve  30  comprises a 3 ml thick PVC plastic, which is capable of withstanding the stress from yarn winding and spinning on a tube mount. The 3 ml PVC plastic sleeve  30  is able to maintain its surface integrity during yarn winding and unwinding operations so as to avoid cracks or burrs that may cause yarn snags.  
      Preferably, a sleeve  30  of the present invention comprises a composition adapted to avoid absorption of moisture and oils from the yarn  20  wound thereon and from the tube  10  itself. In a preferred embodiment, such a sleeve  30  comprise a 3 ml thick PVC plastic.  
      A thickness (t 2 )  37  and a composition of a sleeve  30  adequate to withstand yarn winding pressure and to avoid absorption of moisture and oils from the yarn  20  and the tube  10  provide characteristics, in addition to a smooth (non-burred) surface  31 , to a yarn tube  10  that allow the tube  10  to be reusable. Such characteristics enhance the ability to reuse a tube  10  of the present invention in repeated fashion. Yarn tubes  10  of the present invention can be reused five or more times with the same sleeve  30  without experiencing a reduction in ability to maintain a smooth tube end  17 ,  18  over which yarn  20  can travel.  
      Embodiments of the present invention provide an identification means for distinguishing the yarn  20  to be wound on the outer tube surface  14 . The outer surfaces  14  of yarn tubes  10  often include one or more colors, either as a solid color, in stripes, or in another pattern. Tubes  10  are made having different colors. As such, the color scheme of a tube  10  can be used to identify a particular type of yarn  20 . In embodiments of the present invention, reusable yarn tubes  10  include sleeves  30  comprising a particular color  38  that can be used to represent a particular type of yarn  20  wound onto the tube  10 . As a result, a textile manufacturer could purchase all yarn tubes  10  having no color or the same color, and use colored sleeves  30  to identify the yarn  20  type wound onto a particular tube  10 . In this manner, the textile manufacturer could save the added cost of having multiple smaller portions of the needed number of tubes  10  made in different colors.  
      In embodiments of the present invention, reusable tubes  10  comprise paper  23 . Such a paper tube  10  can be spirally or convolutely wound. Tubes  10  may comprise other materials suitable for yarn tubes  10 . Such materials include steel, aluminum, metallic alloys, and fiber-reinforced polymeric materials, such as epoxides, polyesters, and vinylesters. Such polymeric materials may be reinforced by fibers of glass, carbon, ceramics, aramids, or hybrids thereof. Tubes  10  made from such materials other than paper  23  generally have a wall thickness  13  less that hollow paper tubes  10 .  
      Embodiments of the present invention include yarn tubes  10  having various dimensions, including various lengths  21 , diameters, and wall thicknesses  13 . Sleeves  30  are pre-formed to fit the dimensions of the tubes  10  for which they are intended.  
      Another aspect of the present invention includes methods of making a reusable yarn tube  10 . Referring to  FIGS. 6-8 , an embodiment of such a method  50  includes first providing  51  a hollow tube  10  having a substantially cylindrical wall  12 , an outer surface  14  adapted to carry a yarn  20  thereon, a starting groove  16  in the outer surface  14  proximate one end  17  of the tube  10 , and an opposite, yarn-unwinding end  18 . A pre-formed sleeve  30  having a smooth surface  31  is fitted about a portion  15  of the outer surface  14  of the yarn-unwinding end  18 . The sleeve  30  is formed about the yarn-unwinding end  18  of the tube  10  so that the sleeve  30  provides a smooth surface  31  for the yarn  20  to be wound onto and unwound from the tube  10 .  
      In an embodiment of such a method, fitting the sleeve  30  about the yarn-unwinding end  18  of the tube  10  includes extending  55  the sleeve a distance (d 1 )  32  beyond the yarn-unwinding end  18  such that when the sleeve  30  is formed  58  about the yarn-unwinding end  18 , the sleeve  30  extends across the thickness (t 1 )  13  of the cylindrical wall  12  of the tube  10  without contacting the inside surface  19  of the tube  10 .  
      In preferred embodiments, methods of the present invention include placing  56  the yarn-unwinding end  18  of the tube  10  having the sleeve  30  fitted thereabout onto a sleeve-forming mold  40 . Such a mold  40 , as seen best in  FIG. 6 , can be made of any material suitable for forming a sleeve  30  about a yarn tube  10 , for example, in a heat tunnel. Preferably, such a mold  40  is made from stainless steel. The mold  40  has a substantially cylindrical outer surface  41  having an outside diameter  42  sized to fittingly receive the tube  10 . The mold  40  further includes a ring  43  projecting outwardly from its outer surface  41  for supporting the tube  10  when the tube  10  is placed onto the mold  40 .  
      In embodiments, the ring  43  has a thickness (t 3 )  44  projecting outwardly from the outer surface  41  of the mold  40  such that the distal edge  33  of the sleeve  30  (extending beyond the tube end  18 ) will not contact the ring  43  when the sleeve  30  is formed about the tube  10  and tube end  18 . Accordingly, the outwardly projecting thickness (t 3 )  44  of the mold ring  43  should be no greater than the distance (d 2 )  34  from the inside surface  19  of the tube  10  that the distal edge  33  of the sleeve  30  is located when the sleeve  30  is formed about the tube  10  and tube end  18 . For example, for a tube  10  on which the distal edge  33  of the sleeve  30 , when formed about the tube end  18 , is located {fraction (1/16)} inch from the inside surface  19  of the tube  10 , the ring thickness  44  should be less than {fraction (1/16)} inch. As such, the sleeve  30  will not contact the ring  43  during the form-fitting process. In this manner, the sleeve  30  avoids having its movement interfered by the ring  43  or becoming attached to the ring  43 .  
      In addition, embodiments include a mold  40 , the bottom  45  of which is spaced a distance (d 4 )  46  from a surface below the mold  40 , for example, a mold support base  47  or the top surface of a mold conveyor tray (not shown). The distance (d 4 )  46  the bottom  45  of the mold  40  is spaced above the surface below is sufficient for the portion of the sleeve  30  extending beyond the end  18  of the tube  10  to clear the surface below the mold. This clearance distance (d 4 )  46  allows the portion of the sleeve  30  extending beyond the end  18  of the tube  10  to move freely (and not contact the surface below) during the form-fitting process. For example, in embodiments of the present invention, a pre-formed sleeve  30  having a smooth surface  31  is fitted about a portion  15  of the outer surface  14  of the yarn-unwinding end  18  of a tube  10 . The sleeve  30  is positioned  55  to extend, for example, {fraction (5/16)} inch beyond the tube end  18 . The bottom  45  of the mold  40  is spaced greater than {fraction (5/16)} inch above the top surface of the mold support base  47  below. The tube  10  is placed  56  onto the sleeve-forming mold  40  and supported on the outwardly projecting ring  43  of the mold. When the sleeve  30  is form-fitted  58  about the tube end  18 , the distal edge  33  of the sleeve  30  moves freely of the top surface of the mold support base  47  below and forms about the tube end  18  while avoiding any interference by, or attachment to, the surface below.  
      In embodiments of methods of the present invention, fitting  54  the sleeve  30  about an end  17 ,  18  of the tube  10  includes expanding  53  the sleeve  30  with a cup device (not shown) and placing the cup device and expanded sleeve  30  onto the yarn-unwinding end  18  of the tube  10 .  
      In embodiments of the present invention, the sleeve  30  is thermosettable, such that the sleeve  30  can be formed  58  about an end  17 ,  18  of the tube  10  by application  57  of a pre-determined level of heat for a prescribed amount of time sufficient to form  58  the sleeve  30  about the tube end  17 ,  18 . For example, a sleeve  30  can be formed  58  about a paper yarn tube end  18  by placing a sleeve-forming mold  40  supporting the yarn tube  10  and pre-formed, polyvinyl chloride (PVC) sleeve  30  fitted about the tube end  18  in a heat tunnel (not shown). In one heat tunnel, the mold-tube-sleeve assembly is subjected to a temperature of about 500 degrees Fahrenheit and moved through the tunnel at a relatively slow speed, for example, six feet per minute. In this manner, the PVC sleeve  30  is form-fitted  58  by heat about the end  18  of the tube  10 . Conventional heat tunnels are useful for such a process. In embodiments of automated methods, molds  40  and tubes  10  can be exposed to heat for shorter periods of time, for example, by moving through a heat tunnel at, for example, ten to fifteen feet per minute. In embodiments utilizing different types of heat tunnels, molds  40  and tubes  10  may be exposed to temperatures lower than 500 degrees Fahrenheit to achieve an optimal thermosetting of the sleeve  30  about the tube  10 , so as to create greater efficiency in large scale production.  
      Molds  40  and tubes  10  can be placed onto a tray (not shown), for example, 12 molds  40  on a single tray. In a heat tunnel having an opening that is 16-22 inches wide, a tray carrying 12 molds  40  and tubes  10  can be accommodated. Alternatively, molds  40  and tubes  10  can be placed on a conveyor means in other configurations, for example single file, for moving through a heat tunnel. During the process of preparing yarn tubes  10  for placement into a heat tunnel, the tubes  10  can be inspected  52  for burrs or other defects. At this point, a quality control check can be made to determine whether to reuse a particular tube  10 .  
      In one embodiment of such a method, a pre-formed PVC sleeve  30  having a thickness (t 2 )  37  of about 3 ml fitted  54  about a paper tube end  18  is subjected  57  to a temperature of about 500 degrees Fahrenheit for approximately ten seconds. The sleeve  30  forms  58  about the outer surface  14  of the tube  10  and the tube end  18  such that the sleeve  30  is slidably removable from the tube  10 .  
      In embodiments of methods of the present invention, the sleeve  30  has a color  38  to identify a particular yarn  20  wound onto the tube  10 .  
      Methods of making a reusable yarn tube  10  of the present invention provide embodiments that include automated processes. That is, any or all of the steps in such methods can be automated. For example, with reference to  FIG. 8 , each of the following steps can be automated: (1) providing  51  a cylindrical, hollow yarn tube  10 ; (2) inspecting  52  the tube  10  for burrs or other defects; (3) expanding  53  a pre-formed sleeve  30  with a cup device and placing the cup device and expanded sleeve  30  onto the tube  10 ; (4) fitting  54  the sleeve  30  about a portion  15  of the tube outer surface  14 ; (5) extending  55  the sleeve  30  a distance (d 1 )  32  beyond the end  18  of the tube  10 ; (6) placing  56  the end  18  of the tube  10  having the sleeve  30  fitted thereabout onto a sleeve-forming mold  40 ; (7) applying  57  heat to the tube-sleeve-mold assembly at a pre-determined temperature and time; and/or (8) forming  58  the sleeve  30  about the yarn-unwinding end  18  of the tube  10 . Computer-based logic, mechanisms, and devices can be applied to such processes in order to automatically make a reusable yarn tube  10  of the present invention.  
      Although the present invention has been described with reference to particular embodiments, it should be recognized that these embodiments are merely illustrative of the principles of the present invention. Those of ordinary skill in the art will appreciate that a reusable yarn tube of the present invention may be constructed and implemented in other ways and embodiments. Accordingly, the description herein should not be read as limiting the present invention, as other embodiments also fall within the scope of the present invention.