Abstract:
A forming tube for supporting glass fiber is disclosed that includes an elongate tube having opposing ends, an outer surface adapted to have glass fiber wound thereon, and an inner surface, the tube defining a central opening extending along a longitudinal axis of the tube for receiving a mandrel, the tube further defining an opening extending between the inner and outer surfaces thereof and located proximate one of the opposing ends, the opening designed to facilitate access to a start-up portion of the glass fiber from at least the central opening of the tube.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention generally relates to processes for forming, collecting, and unwinding of glass fiber, and more particularly to forming tubes for use in forming, storing, and collecting such fibers. In general terms, the process for producing glass fiber includes heating raw materials into a molten glass and directing the molten glass through orifices and bushings to form hundreds of tiny filaments that are attenuated, cooled, and gathered to form strands. A strand is wound around a rotating cylindrical tube that is mounted on a rotating cylinder or mandrel, which is also known in the art as a collet. The rotating tube is known as a forming tube and supplies tension to the fibers to wind the fibers into a package that is also known in the art as a glass cake. After the winding is complete, the glass fiber cake is further processed, and then the forming tube is collapsed and extracted from the interior of the cake so that the strand can be unwound by grasping the interior end or transfer tail.  
         [0002]     One of the difficulties in processing the glass fiber cake is that the transfer tail is often difficult to locate. It is known that a transfer tail can be included in the initial wraps of the glass fiber about the forming tube, which can be located and tied to the outer end of glass fiber on an adjacent glass fiber cake. Therefore, the transfer tail of one glass fiber cake and the connected outer end of glass fiber on an adjacent provide an uninterrupted flow of glass fiber from one glass fiber cake to another.  
         [0003]     However, the transfer tail is often lost when the forming tubes are collapsed and removed from the inside of the glass fiber cake. In order to locate the transfer tail of a particular cake, several layers or wraps of the glass fiber must be removed, which creates unnecessary material waste and requires extra time. In addition, the glass fiber may be damaged by the removal of several layers of glass fiber, which is typically performed by a fingernail, hook device, or other sharp tool. As such, there is a need for capturing the transfer tail of a fiberglass cake that is efficient and avoids damaging the cake. There is also a need for removing a tube from a glass fiber cake that consolidates removal of the forming tube while locating the transfer tail of the glass fiber.  
       SUMMARY OF THE INVENTION  
       [0004]     These and other needs are addressed by a collapsible core or forming tube for supporting glass fiber according to the presently claimed invention. Advantageously, the forming tube defines an opening for locating and accessing glass fiber that is wound about the tube that enables the tube to be removed from the glass fiber while accessing and trapping the glass fiber through the opening, thereby increasing productivity and decreasing waste.  
         [0005]     More particularly, the forming tube for supporting glass fiber according to one embodiment comprises a hollow, elongate tube having opposing ends with an outer surface designed to receive the glass fiber, which is wound about the tube to form a glass fiber cake having a start-up portion. The tube defines a central opening that extends along a longitudinal axis of the tube and is designed to receive a mandrel. The tube can be formed from a variety of materials, such as paperboard, polymeric materials, and metallic materials. The tube further defines an opening that extends through the inner and outer surfaces of the tube and is located proximate one of the opposing ends. The opening is designed to facilitate access to a start-up portion of the glass fiber from at least the central opening of the tube.  
         [0006]     The opening may be positioned in various ways. More specifically, the opening may be positioned inwardly from one of the opposing ends. The opening may also begin at one of the opposing ends, e.g., a notch or half circle that is open at the end of the tube, and extend along the longitudinal axis toward the other end. It is also possible that the tube defines at least one opening at each of the opposing ends.  
         [0007]     Methods of removing the tube from the glass fiber cake are also provided. One method includes the steps of accessing a start-up portion of glass fiber of the glass fiber cake through an opening located proximate one end of the tube. The start-up portion is captured by extending a tool radially outwardly through the opening. The tube is then removed from the glass fiber cake so that the start-up portion is spaced from the glass fiber cake and thereby readily identifiable. To assist with removal of the tube from the glass fiber cake, at least a portion of the tube may be collapsed. One method also includes pushing or pulling the start-up portion through the opening and holding the start-up portion in place while removing the tube. Accordingly, the end of the glass fiber is then available to an operator for connecting with another glass fiber, such as a glass fiber associated with an adjacent glass fiber cake. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)  
       [0008]     Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:  
         [0009]      FIG. 1  is a schematic view of a manufacturing operation for making glass fiber and the like according to one embodiment of the present invention;  
         [0010]      FIG. 2  is a perspective view of a glass fiber cake according to one embodiment of the present invention;  
         [0011]      FIGS. 3   a - 3   d  are perspective views of forming tubes according to the present invention;  
         [0012]      FIGS. 4   a - 4   b  are partial perspective views of a forming tube and glass fiber cake according to the present invention;  
         [0013]      FIG. 5  is a partial, cut-away perspective view of a forming tube with glass fiber according to one embodiment of the present invention;  
         [0014]      FIG. 6  is a partial, cut-away perspective view of a forming tube with glass fiber according to one embodiment of the present invention; and  
         [0015]      FIGS. 7-10  illustrate a method of removing a forming tube from a glass fiber cake according to one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.  
         [0017]     Turning now to the figures,  FIG. 1  illustrates a schematic view of a manufacturing operation for making glass fiber and the like according to one embodiment of the present invention. The manufacturing operation  10  includes one or more batch material hoppers  12  for receiving raw materials or batch ingredients  14 , which can include SiO 2 , Al 2 O 3 , CaO, MgO, and B 2 O 3 . The hoppers  12  release a predetermined mixture of raw materials  14  into a blender  16  to create a more homogenous mass of particles. The raw materials  14  are then directed to a furnace  18  where the materials are reduced to molten glass. The furnace  18  can be one of many types that are known in the art and is capable of reaching temperatures in excess of 2800° F. Heaters  20  can also be used along the channel  22  to maintain a desired temperature of the molten glass particles.  
         [0018]     The molten glass is then directed through a plurality of bushings  28  that contain hundreds of tiny orifices. The molten glass flows through the orifices to form filaments  30  that are attenuated, cooled and gathered together to form strands. In particular, the filaments  30  are directed toward a nip  36  that may also include a twist or other such procedure to form a strand  31 . In one embodiment, a binder applicator or other chemical treatment device  32  applies a chemical  34 , such as sizing or a binder agent, to the filaments  30  to coat the filaments and reduce filament breakage during subsequent processing steps, such as twisting. The glass fiber or strand  31  is then directed to a take-up roll, which is preferably a cylindrical tube or mandrel  38  that is also known in the art as a collet. A forming tube  40  is positioned on the cylindrical mandrel  38 , which is rotated at high speed such as 2000 to 4000 collet rpm (3000 to 4500 m/min. linear speed) so that the strand  31  is wound about the tube to form a glass fiber pack or cake  42 . When a desired length of glass fiber strand  31  is wound about the forming tube  40 , the cake  42  (and other glass fiber cakes, if applicable) is then directed to a dryer  44  or the like. Other processes that are known in the art can also be applied, such as twisting, creeling, warping, texturizing, and the like. These processes typically require that the forming tube  40  be removed from the inside of the glass fiber cake  42 , as discussed further below.  
         [0019]      FIG. 2  shows a finished glass fiber cake  42  having a continuous strand of glass fiber  31  wound about the outer surface  50  of the tube  40 . The cake  42  is formed by a plurality of initial wraps  56  having a starting end that is eventually connected to the transfer tail of an adjacent tube (not shown). The starting end and initial wraps  56  are initially wrapped around the outer surface  50  of the tube  40  while the tube turns at high speed. When the cake  42  is formed, a transfer tail  46  extends to an adjacent tube (not shown) and connects to that tube&#39;s starting end and helps form the initial wraps. As shown in  FIG. 2 , the forming tube  40  includes an opening  60  that extends through the wall of the tube from the outer surface  50  to the inner surface  54 . As shown, the opening  60  is spaced away from an end  52 , although this is not a requirement, as discussed below.  
         [0020]      FIGS. 3A-3D  illustrate various embodiments of forming tubes and openings according to the present invention. More specifically,  FIG. 3A  shows a forming tube  40  having a single opening  60  that is spaced from the end  52  to define a gap  62  therebetween. The opening  60  is shown as having a rectangular shape, although other geometric shapes, including but not limited to polygonal, circular, and oval ( FIG. 3D ), are contemplated by the present invention.  FIG. 3B  illustrates an alternative embodiment, whereby the forming tube  40  includes a plurality of openings that extend from the outer surface  50  of the tube to the inner surface  54  thereof. In this regard, the term “opening” is given a broad meaning, but preferably is defined as extending through the tube  40  so that objects can be extended through an open space defined by the opening.  FIG. 3C  illustrates another alternative embodiment, wherein the opening  60  is positioned proximate the opposite end  53 . While it is possible that the opening  60  could be spaced anywhere along the length of the tube  40 , it is preferable that the opening (or openings) is spaced or located proximate one or both of the ends  52  and  53  of the tube so that glass fiber extending over the opening can be captured, as discussed more fully below.  
         [0021]      FIGS. 4A-4B  illustrate alternative embodiments of the forming tube  40 . In particular,  FIG. 4A  illustrates a partial perspective view of a tube having a plurality of initial wraps  56  wound about the outer surface  50  of the tube  40 . The opening  60  is located at the end  52  and has the form of a “V” that opens to the end to form a notch instead of a closed shape that is spaced away from the end  52 .  FIG. 4B  illustrates an alternative embodiment, whereby the opening  60  has a curved shape instead of a “V” shape, and any other notch or shape that “opens” to one or both ends  52  and  53  is contemplated by the present invention. As shown, the initial wraps  56  of the fiber  31  extend over the openings  60  and can be accessed and are visible from the inside surface  54  of the tube  40 .  
         [0022]      FIGS. 5 and 6  illustrate one method of capturing the initial wraps  56  and preparing the cake  42  for downstream processes. As discussed above, the tube  40  is often removed from the glass fiber cake  42 , and in order to reduce fiber waste and improve efficiency, the initial wraps  56  that extend over the opening  60  are captured by a tool  66  having a hook  67  or the like that is extended through the opening to capture the initial wraps. As shown in  FIG. 5 , the hook  67  of the tool  66  is extended through the opening  60  from the inside surface  54 , although it is contemplated that the hook  67  could be extended through the opening from the outer surface  50  to the inner surface  54 .  FIG. 6  shows the initial wraps  56  being pulled in a radial and/or longitudinal direction through the opening  60  by pulling the tool  66  so that the initial wraps are captured and pulled by the hook  67 . Because the initial wraps  56  are preferably one of the initial wraps of fiber  31  about the tube  40 , the initial strands  56  that are captured by the hook  67  provide an optimized and realistic “end” that maximizes the effective length of the fiber  31  wrapped around the tube  40 .  
         [0023]      FIGS. 7-10  illustrate various method steps of removing a forming tube from a glass fiber cake according to one embodiment of the present invention. In particular, when the initial wraps  56  are pulled through the opening  60  by the tool  66  (not shown for clarity), the tube  40  is collapsed so that the inner surface  54  is pressed toward itself, as shown in  FIG. 8 .  FIG. 9  shows the tube  40  as it is collapsed even further so that the outer surface  50  forms an inner folded surface  51 A and an outer folded surface  51 B. Compressive forces F are applied proximate the folded ends  55  of the tube  40 , such as by pinching the tube together with an operator&#39;s hands or by a tool or machine. As such, the effective diameter of the tube  40  is reduced, thus allowing the tube to be removed from the glass fiber cake  42 .  FIG. 10  illustrates the forming tube  40  being removed from the cake  42 , whereby the initial wraps  56  are shown as extending out one end  52  of the tube so that an operator can easily grasp the initial wraps and to locate an end for tying to an adjacent cake or other such process. The process steps shown in  FIGS. 7-10  are only one method of removing the tube. Variations in the process steps are contemplated by the present invention, as long as the tube  40  is removed and the initial wraps  56  are captured and retained for connection to an adjacent cake.  
         [0024]     Accordingly, the opening  60  provided by the present invention allows an operator to easily locate and capture initial strands or wraps  56  of glass fiber  31  that is wrapped around the forming tube  40  to form a glass fiber cake  42 . The positioning and shape of the opening (or openings)  60  allows for easy access to the initial wraps  56  to quickly and easily locate an end of the fiber  31 , thereby eliminating unnecessary waste and increasing efficiency in downstream processes.  
         [0025]     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.