Bags, Method of Making Bags and Method of Use Thereof for Enveloping Rectangular Bales

Abstract

A continuous web of closed, preformed end-to-end bags for enclosing bales of material are made by forming an elongate sheet into a helix tube, flattening the tube into first and second elongate bag walls and securing the bag walls at closure seams located along the flattened helix tube. The helix tube is formed by nesting the elongate sheet side edges into U-shapes and sewing. The bag walls are secured to one another by nesting them into U-shapes and sewing. Bales are enveloped by severing the web and thereby providing a bag with an open end, separating the bag walls, inserting a bale therein, closing the bag and severing from the remaining web. Each bag is located along the web with a pair of sensors which provide a locating signal responsive to the bag closure seams.

What is claimed is: 
     
         1 . A method of making a plurality of preformed bags for enveloping bales of material, wherein said plurality of bags are closed and arranged end-to-end, said method of making the plurality of closed, preformed end-to-end bags comprising the steps of:
 providing an elongate sheet of material having opposing ends and first and second opposing side edges extending between said opposing ends;   forming a helix tube by twisting said elongate sheet opposing ends in relative opposite directions and securing said first and second side edges to one another;   flattening said tube and forming opposing first and second elongate bag walls joined at opposing side fold edges; and,   securing said opposing first and second elongate bag walls to one another at desired spaced distances between said opposing ends for thereby making said plurality of closed preformed end-to-end bags.   
     
     
         2 . The method of  claim 1  wherein said securing said opposing first and second elongate bag walls to one another further comprises the steps of:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; and, 
 sewing the legs of said nested U-shapes to one another. 
 
     
     
         3 . The method of  claim 1  wherein said securing said first and second side edges to one another further comprises the steps of:
 forming said first side edge into an outer U-shape and said second side edge into an inner U-shape; 
 nesting said inner U-shape within said outer U shape; and, 
 sewing the legs of said nested U-shapes to one another. 
 
     
     
         4 . The method of  claim 3  wherein said securing said opposing first and second elongate bag walls to one another further comprises the steps of:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; and, 
 sewing the legs of said nested U-shapes to one another. 
 
     
     
         5 . The method of  claim 4  wherein said elongate sheet of material comprises polypropylene having a thickness of less than 0.006 inch. 
     
     
         6 . The method of  claim 1  wherein said flattening said tube and forming opposing first and second elongate bag walls joined at opposing side fold edges further comprises the steps of:
 folding said first and second bag walls and forming gussets at said side fold edges; 
 wherein each of said gussets comprise a pair of gusset walls; and, 
 wherein at each side fold edge one of said gusset walls is joined to said first bag wall, the other one of said gusset walls is joined to the second bag wall and said gusset walls are joined to one another. 
 
     
     
         7 . The method of  claim 6  wherein said securing said opposing first and second elongate bag walls to one another further comprises the steps of:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; 
 sewing the legs of said nested U-shapes to one another; and, 
 at said gussets, forming said gusset walls into gusset U-shapes, sandwiching said gusset U-shapes between said outer and inner U-shapes and sewing the legs of said outer U-shape, inner U-shape and gusset U-shapes together. 
 
     
     
         8 . The method of  claim 7  wherein said securing said first and second side edges to one another further comprises the steps of:
 forming said first side edge into an outer U-shape and said second side edge into an inner U-shape; 
 nesting said inner U-shape within said outer U shape; and, 
 sewing the legs of said nested U-shapes to one another. 
 
     
     
         9 . The method of  claim 8  wherein said elongate sheet of material comprises polypropylene having a thickness of less than 0.006 inch. 
     
     
         10 . The method of  claim 1  further wherein bales of material are enveloped in said bags with a method comprising the steps of:
 severing said plurality of closed, preformed end-to-end bags between two closed ends and providing a first bag having an open end and a closed end; 
 separating said opposing first and second elongate bag walls at said open end; 
 inserting a bale into said bag through said open end; 
 closing said open end for thereby enveloping the bale in said bag; and, 
 severing said plurality of closed, preformed end-to-end bags between said first bag closed end and another bag prior to inserting a bale in said another bag. 
 
     
     
         11 . The method of  claim 10  wherein said securing said opposing first and second elongate bag walls to one another further comprises the steps of:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; and, 
 sewing the legs of said nested U-shapes to one another. 
 
     
     
         12 . The method of  claim 10  wherein said securing said first and second side edges to one another further comprises the steps of:
 forming said first side edge into an outer U-shape and said second side edge into an inner U-shape; 
 nesting said inner U-shape within said outer U shape; and, 
 sewing the legs of said nested U-shapes to one another. 
 
     
     
         13 . The method of  claim 10  wherein said flattening said tube and forming opposing first and second elongate bag walls joined at opposing side fold edges further comprises the steps of:
 folding said first and second bag walls and forming gussets at of said side fold edges; 
 wherein each of said gussets comprise a pair of gusset walls; and, 
 wherein at each side fold edge one of said gusset walls is joined to said first bag wall, the other one of said gusset walls is joined to the second bag wall and said gusset walls are joined to one another. 
 
     
     
         14 . The method of  claim 13  wherein said securing said opposing first and second elongate bag walls to one another further comprises the steps of:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; 
 sewing the legs of said nested U-shapes to one another; and, 
 at said gussets, forming said gusset walls into gusset U-shapes, sandwiching said gusset U-shapes between said outer and inner U-shapes and sewing the legs of said outer U-shape, inner U-shape and gusset U-shapes together. 
 
     
     
         15 . The method of  claim 1  further comprising the step of spirally winding said closed, preformed end-to-end bags into a roll. 
     
     
         16 . The method of  claim 1  wherein said elongate sheet of material comprises polypropylene having a thickness of less than 0.006 inch. 
     
     
         17 . A method of enveloping bales of material with closed preformed end-to-end bags provided in an elongate web, wherein the web includes opposing first and second elongate bag walls joined at opposing side edges along the elongate web and includes bag closure seams at spaced distances along the web whereat the opposing first and second elongate bag walls are secured to one another thereby defining said plurality of closed preformed end-to-end bags, said method of enveloping comprising the steps of:
 severing said elongate web between two closed ends and providing a first bag having an open end and a closed end;   separating said opposing first and second elongate bag walls at said open end;   inserting a bale into said bag through said open end;   closing said open end for thereby enveloping the bale in said bag; and,   severing said elongate web between said first bag closed end and another bag closed end prior to inserting a bale in said another bag.   
     
     
         18 . The method of  claim 17  wherein said step of severing said elongate web between said first bag closed end and another bag closed end occurs between said steps of separating and inserting. 
     
     
         19 . The method of  claim 17  further comprising the step of locating each closed preformed end-to-end bag by sensing the closure seams. 
     
     
         20 . The method of  claim 19  wherein said sensing the closure seams comprises providing a pair of sensors, each of said sensors providing a locating control signal responsive to a closure seam, and wherein said step of locating comprises the presence of the substantially simultaneous control signals from both said pair of sensors. 
     
     
         21 . The method of  claim 20  wherein said sensors each comprise a pivotable sensor arm having a terminal end adapted to engage the closure seams and a sensor adapted to sense the movement of said pivotable sensor arms. 
     
     
         22 . The method of  claim 21  wherein said closure seams are made by:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; and, 
 securing the legs of said nested U-shapes to one another. 
 
     
     
         23 . The method of  claim 19  wherein said closure seams are made by:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; and, 
 securing the legs of said nested U-shapes to one another. 
 
     
     
         24 . The method of  claim 17  wherein said closure seams are made by:
 forming said first bag wall into an outer U-shape and said second bag wall into an inner U-shape; 
 nesting said inner U-shape within said outer U-shape; and, 
 securing the legs of said nested U-shapes to one another.