Bag with thermal welded back seam

Abstract

A bag having a thermal welded back seam is provided. The bag may be formed primarily of a thermoplastic material and may be in the form of a polywoven bag.

1 . A bag comprising:
 a thermoplastic front panel;   a thermoplastic back panel having left and right panel segments;   an overlap of the left and right panel segments; and   a thermal welded back seam which extends along the overlap and is free of a hot melt glue which is different from the front and back panels.   
     
     
         2 . The bag of  claim 1  wherein the front and back panels define therebetween an interior chamber;
 the front panel has an inner surface which faces the interior chamber; 
 the back seam has an inner surface which faces the interior chamber; and further comprising broken welds along the inner surface of the back seam and the inner surface of front panel. 
 
     
     
         3 . The bag of  claim 1  wherein the front panel has opposed first and second side edges and opposed first and second end edges;
 the back panel has opposed first and second side edges and opposed first and second end edges; 
 the first and second side edges of the back panel are respectively adjacent the first and second side edges of the front panel; 
 the first and second end edges of the back panel are respectively adjacent the first and second end edges of the front panel. 
 
     
     
         4 . The bag of  claim 3  wherein the back seam extends from adjacent one of the first and second end edges of the back panel toward the other of the first and second end edges of the back panel. 
     
     
         5 . The bag of  claim 4  wherein the back seam extends from adjacent the one of the first and second end edges of the back panel to adjacent the other of the first and second end edges of the back panel. 
     
     
         6 . The bag of  claim 5  wherein the back seam extends from the one of the first and second end edges of the back panel to the other of the first and second end edges of the back panel. 
     
     
         7 . The bag of  claim 1  further comprising a first fold extending along the first side edges; and a second fold extending along the second side edges. 
     
     
         8 . The bag of  claim 7  further comprising a third fold extending along the first side edges; and a fourth fold extending along the second side edges. 
     
     
         9 . The bag of  claim 8  further comprising a fifth fold extending along the first side edges; and a sixth fold extending along the second side edges. 
     
     
         10 . The bag of  claim 7  wherein the first fold defines the first side edges; and the second fold defines the second side edges. 
     
     
         11 . The bag of  claim 3  wherein the back seam is substantially parallel to the first side edges and the second side edges. 
     
     
         12 . The bag of  claim 1  further comprising
 an interior chamber defined between the front and back panels; 
 a first entrance opening of the interior chamber adjacent the first end edges; and 
 a second entrance opening of the interior chamber adjacent the second end edges. 
 
     
     
         13 . The bag of  claim 12  wherein the back seam extends from adjacent one of the first and second entrance openings toward the other of the first and second end openings. 
     
     
         14 . The bag of  claim 1  further comprising
 an interior chamber defined between the front and back panels; 
 an entrance opening of the interior chamber adjacent the first end edges; 
 an end seam extending from adjacent the first side edges to adjacent the second side edges; 
 wherein the back seam extends from adjacent one of the entrance opening and end seam toward the other of the entrance opening and end seam. 
 
     
     
         15 . The bag of  claim 14  wherein the back seam extends from the entrance opening to the end seam. 
     
     
         16 . The bag of  claim 1  wherein the front and back panels are formed from a single sheet of thermoplastic material. 
     
     
         17 . The bag of  claim 16  wherein the thermoplastic material is a polywoven thermoplastic material. 
     
     
         18 . The bag of  claim 1  wherein each of the front and back panels is formed of a polywoven thermoplastic material. 
     
     
         19 . The bag of  claim 1  further comprising
 a first gusset extending along the first side edges; and 
 a second gusset extending along the second side edges. 
 
     
     
         20 . A bag comprising:
 a tube of thermoplastic sheet material which defines an interior chamber and includes a front panel and a back panel having left and right panel segments; wherein the front panel has an inner surface which faces the interior chamber;   an overlap of the left and right panel segments;   a thermal welded back seam which extends along the overlap and has an inner surface which faces the interior chamber; and   broken welds along the inner surface of the back seam and the inner surface of front panel.