Patent Publication Number: US-2002008517-A1

Title: Octagon shaped flexible intermediate bulk container and method of manufacture

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
     [0001] This is a continuation-in-part application under 37 C.F.R. §1.63 of application Ser. No. 09/771,270 filed Jan. 26, 2001, currently pending, which is a continuation application of Application Serial No.  09 / 515 , 631  filed Feb. 29, 2000, now U.S. Pat. No. 6,244,443, which is a continuation-in-part of application Ser. No. 09/458,362 filed Dec. 9, 1999, now U.S. Pat. No. 6,220,755, which is a continuation-in-part of application Ser. No. 09/390,403 filed Sep. 3, 1999, now U.S. Pat. No. 6,203,198. 
    
    
     
       TECHNICAL FIELD  
       [0002] The present invention relates generally to flexible intermediate bulk containers, and more particularly to an octagon shaped flexible intermediate bulk container formed from a unitary length of woven fabric comprising alternating stiffening panel receiving pockets and high strength sections.  
       BACKGROUND AND SUMMARY OF THE INVENTION  
       [0003] U.S. Pat. No. 6,244,443 granted Jun. 12, 2001 to Nickell, et al. and assigned to the assignee hereof discloses and claims an octagon shaped stackable flexible intermediate bulk container a.k.a. bulk bag, and a method of manufacturing the octagon shaped bulk bag. In accordance with the method of the &#39;443 patent, two substantially identical sheets of woven polypropylene fabric are positioned one on top of the other with the sides and ends of the sheets in alignment. The sheets are joined by seven transversely extending sew lines and the opposite ends of the sheets are sewn together to define eight stiffening panel receiving pockets. A bottom wall is attached to one end of the resulting construction by sewing, a stiffening panel is inserted into each of the stiffening panel receiving pockets, and the tops of the stiffening panel receiving pockets are thereafter closed by sewing.  
       [0004] The present invention comprises an octagon shaped flexible intermediate bulk container a.k.a. bulk bag and a method for manufacturing the octagon shaped bulk bag which incorporates a substantial improvement over the octagon shaped bulk bag and the manufacturing method of the &#39;443 patent. In accordance with the present invention an octagon shaped bulk bag is fabricated from a unitary length of woven fabric comprising alternating stiffening panel receiving pockets and high strength sections. More particularly, the stiffening panel receiving pockets comprise spaced apart woven polypropylene fabric sections each comprising perpendicularly extending warp and woof polypropylene tapes or filaments. The alternating high strength sections comprise the same polypropylene tapes or filaments which are utilized in the fabrication of the woven polypropylene fabric sections comprising the stiffening panel receiving pockets, but which are woven together to define integral high strength sections having approximately twice the density and substantially greater strength as compared with the woven polypropylene fabric panels of the stiffening panel receiving pocket.  
       [0005] The use of the high strength sections in the fabrication of the octagon shaped bulk bag of the present invention comprises at least two distinct advantages over the prior art as represented by the octagon shaped bulk bag and method of manufacture of the &#39;443 patent. First, the use of the high strength sections of the present invention eliminates the necessity of forming transversely extending sew lines to define the stiffening panel receiving pockets of an octagon shaped bulk bag. Second, the use of the high strength sections of the present invention provides a convenient location for the attachment of lift loops which are commonly employed in bulk bag manufacture. Other advantages deriving from the use of the method of the present invention will readily suggest themselves to those skilled in the art.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0006] A more complete understanding of the present invention may be had by reference to the following Detailed Description, when taken in conjunction with the accompanying Drawings, wherein:  
     [0007]FIG. 1 is a perspective view illustrating an octagon shaped flexible intermediate bulk container constructed in accordance with the invention in which certain parts have been broken away more clearly to illustrate certain features of the invention;  
     [0008]FIG. 2 is an illustration of the major component part of the octagon shaped flexible intermediate bulk container of FIG. 1 in which certain parts have been broken away more clearly to illustrate certain features of the invention;  
     [0009]FIG. 3 is an enlargement of a portion of FIG. 2 in which certain parts have been broken away more clearly to illustrate certain features of the invention; and  
     [0010]FIG. 4 is a top view of the octagon shaped flexible intermediate container of FIG. 1 in which certain component parts have been broken away more clearly to illustrate features of the invention.  
    
    
     DETAILED DESCRIPTION  
     [0011] Referring now to the Drawings, and particularly to FIGS. 1 and 4, there is shown an octagon shaped flexible intermediate bulk container  10  incorporating in the present invention. As is well known by those skilled in the art, flexible intermediate bulk containers are commonly known as bulk bags. The bulk bag  10  comprises eight substantially identical stiffening panel receiving pockets  12 . The pockets  12  are separated by substantially identical high strength sections  14 . The bulk bag  10  further includes a bottom wall  16  which is secured to the stiffening panel receiving pockets  12  and the high strength sections  14  by sewing as indicated by the sew line  18 .  
     [0012] Each of the stiffening panel receiving  12  receives a stiffening panel  22 . The stiffening panels  22  of the present invention may be manufactured from plastic panels of the type sold by Coroplast of Dallas, Tex., under the trademark COREX(TM). Other types of plastic panels may also be used, depending upon the requirements of particular applications of the invention. The stiffening panels  22  may also be formed from various types of paperboard; fiberboard, including medium density fiberboard (MDF); cardboard; plywood; and other materials depending upon the ability of stiffening panels formed from such materials to resist bending. After the stiffening panels  22  are positioned in the pockets  12 , each of the pockets  12  may be closed at its upper end by sewing, as indicated by the sew line  24 . Alternatively, the stiffening panels  22  may be removably retained in the pockets  12  by snaps, hook-and-loop fasteners, etc., thereby facilitating folding of the bulk bag  10  for the storage or shipment.  
     [0013] Referring particularly to FIG. 1, the bulk bag  10  may be provided with a plurality of lift loops  30  depending upon the requirements of particular applications of the invention. If used, the lift loops  30  are preferably secured to the high strength sections  14  by sewing as indicated at  32 . The bulk bag  10  may also be provided with tabs  34  which are fastened to the bottom wall  16  by sewing and which are utilized to secure the bulk bag  10  to a pallet P. The tabs  34  may be used in addition to or in lieu of the lift loops  30  depending upon the requirements of particular applications of the invention. Those skilled in the art will appreciate the fact that the bulk bag may be provided with other types and kinds of lifting and/or securing apparatus, if desired.  
     [0014] The method of the present invention is illustrated in FIGS. 2 and 3. The stiffening panel receiving pockets  12  and the high strength sections  14  comprise unitary subassembly  40 . The stiffening panel receiving pockets  12  of the subassembly  40  each comprise spaced apart single layer panels  12 A and  12 B. The single layer panels  12 A and  12 B comprising the stiffening panel receiving pockets  12  comprise warp and woof fibers which may comprise either tapes or filaments formed from polypropylene, polyethylene or other plastic materials depending upon the requirements of particular applications of the invention. The warp and woof fibers are woven in the conventional manner to form spaced apart single layer panels  12 A and  12 B comprising each stiffening panel receiving pocket  12 .  
     [0015] The high strength sections  14  of the subassembly  40  are fabricated utilizing the same warp and woof fibers that are utilized in the fabrication of the single layer panels comprising the stiffening panel receiving pockets  12 . However, within the high strength sections  14  the warp and woof fibers utilized in the fabrication of the spaced apart panels comprising the stiffening panel receiving pockets  12  are woven into an integrated structure having substantially twice the density and considerably more strength as compared with one of the single layer panels comprising the stiffening panel receiving pockets  12 .  
     [0016] The subassembly  40  includes high strength end sections  42  which are formed identically to the high strength sections  14 . The end sections  42  are joined together by sewing as indicated by the sew line  44  (FIGS. 1 and 4). If used, the lift loops  30  are preferably secured to the high strength sections  14  prior to the joinder of the end sections  42 . As will be appreciated by those skilled in the art, the increased density and strength of the high strength sections  14  provides a superb attachment point for the lift loops  30 .  
     [0017] The increased density and strength of the high strength sections  14  of the subassembly  40  as compared with that of the single layer panels comprising the stiffening panel receiving pockets  12  is diagrammatically illustrated in FIG. 3 wherein the lift loops  30  are omitted for clarity. As is indicated above, and as will be appreciated by those skilled in the art, the same warp and woof fibers which are utilized in the construction of the single layer panels comprising the stiffening panel receiving pockets  12  are utilized in the construction of the high strength sections  14 . Therefore, in actual practice, there is not a clear line of demarkation between the single layer panels comprising the pockets  12  and the integral construction of the high strength sections  14 .  
     [0018] Additional embodiments of the invention are diagrammatically illustrated in FIG. 2. In the embodiment of the invention hereinabove, the subassembly  40  comprises eight stiffening panel receiving pockets  12  having reference to the dashed line  46 , a second embodiment of the invention comprises two subassemblies  40  each comprising four stiffening panel receiving pockets  12 . In accordance with a third embodiment of the invention, four subassemblies  40  are provided each comprising two stiffening panel receiving pockets  12 . As will be appreciated by those skilled in the art, an end section  42  is provided at each end of each subassembly  40  regardless of how many subassemblies  40  are utilized in the construction of a bulk bag.  
     [0019] It will therefore be understood that the present invention comprises an improvement over the octagon shaped bulk bag and the method of manufacturing octagon shaped bulk bags disclosed and claimed in U.S. Pat. No. 6,244,443. In particular, the method of the present invention eliminates the sewing step which is necessary to separate the stiffening panel receiving pockets of the bulk bag of the &#39;443 patent. In lieu thereof, the method of the present invention provides high strength sections interposed between the stiffening panel receiving pockets which provides superior strength and afford a convenient location for the attachment of the lift loops.  
     [0020] Although preferred embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.