Double-bottom side-welded bag

Abstract

The present invention relates to flexible double-bottom bags having an outer web which is folded upon itself to form a front panel and a back panel The outer web includes an inward-facing cross-sectional gusset opposite the open mouth of the bag and centered along the width of the bag joining the front panel to the back panel and creating an outer bottom portion of the bag. The bags also have an inner web which is folded upon itself to form a front panel and a back panel.

What is claimed: 
     
         1 . A double-bottom bag having an open mouth, an opposing bottom and a width, comprising:
 a. an outer web having a first side edge, an opposing second side edge and folded upon itself thereby defining:
 i. a front panel having a length; 
 ii. a back panel having a length; 
 iii. an inward-facing cross-sectional gusset opposite the open mouth and centered along the width of the bag which joins the front panel to the back panel and forms an outer bottom portion of the bag; 
   b. an inner web having a first side edge, an opposing second side and folded upon itself thereby defining:
 i. a front panel having a length which is less than the length of the front panel of the outer web; 
 ii. a back panel having length which is less than the length of the back panel of the outer web; 
 iii. an inward-facing cross-sectional gusset opposite the open mouth and centered along the width of the bag which joins the front panel to the back panel and forms an inner bottom portion of the bag; 
   c. a first side-seam affixing the first side edge of both the inner and outer webs together, and affixing the front and back panels of the outer web together along the first side edge;   d. an opposing second side-seam affixing the opposing second side edge of both the inner and outer webs together, and affixing the front and back panels of the outer web together along the opposing second side edge; and   e. wherein the inward-facing cross-sectional gussets of both the inner and outer webs expand to form a square or rectangular cross-sectional bag bottom upon receiving a material to be packaged.   
     
     
         2 . A bag according to  claim 1 , wherein a substantial portion of the front panel of the outer web and a substantial portion of the front panel of the inner web face each other and are unlaminated. 
     
     
         3 . A bag according to  claim 1 , wherein a substantial portion of the back panel of the outer web and a substantial portion of the back panel of the inner web face each other and are unlaminated. 
     
     
         4 . A bag according to  claim 1 , wherein the length of the back panel of the outer web is greater than the length of the front panel of the outer web. 
     
     
         5 . A bag according to  claim 4 , wherein the back panel of the outer web comprises at least one aperture proximal to the open mouth of the bag. 
     
     
         6 . A bag according to  claim 4 , wherein the back panel of the outer web comprises a pair of apertures proximal to the open mouth of the bag. 
     
     
         7 . A bag according to  claim 1 , wherein the outer web comprises a heat-fusible material. 
     
     
         8 . A bag according to  claim 1 , wherein the outer web is a flexible thermoplastic film. 
     
     
         9 . A bag according to  claim 8 , wherein the flexible thermoplastic film is substantially transparent. 
     
     
         10 . A bag according to  claim 8 , wherein the flexible thermoplastic film is a three ply film. 
     
     
         11 . A bag according to  claim 8 , wherein the flexible thermoplastic film comprises polyethylene. 
     
     
         12 . A bag according to  claim 1 , wherein the inner web comprises a heat-fusible material. 
     
     
         13 . A bag according to  claim 1 , wherein the inner web is a flexible thermoplastic film. 
     
     
         14 . A bag according to  claim 13 , wherein the flexible thermoplastic film is substantially opaque. 
     
     
         15 . A bag according to  claim 13 , wherein the flexible thermoplastic film is a three ply film. 
     
     
         16 . A bag according to  claim 13 , wherein the flexible thermoplastic film comprises polyethylene. 
     
     
         17 . A bag according to  claim 1 , wherein the first side-seam is a heat seal. 
     
     
         18 . A bag according to  claim 1 , wherein the second side-seam is a heat seal. 
     
     
         19 . A bag according to  claim 1 , wherein the inner web is embossed. 
     
     
         20 . A bag according to  claim 1 , wherein the bag is a bread bag.