Method and system for folding and sealing bags

Abstract

A system including multiple bags each having a first adhesive material on a first panel, and second adhesive material on a stepped construction of the bag, and a third section of each bag being free of adhesive, further including a hot air manifold along which the bag is conveyed after the bag has been filled with contents and closed, which heats the first adhesive material and the second adhesive material to their adhesive states; a section of the hot air manifold along which the third section free of adhesive is conveyed, which minimizes adhesive contamination; a blade to bias the stepped construction of the bag to follow along the manifold; and a trailing end of the blade to fold the bag along its third section without displacing or expelling adhesive from the third section, which minimizes adhesive contamination of surfaces of the bag.

1 . A bag to be filled with contents, comprising:
 a polymeric tube having a first panel, a second panel and side gussets;   the first panel having a first section and a second section;   an end of the tube having a stepped construction, which includes the second section, portions of the side gussets extending beyond the second section and a portion of the second panel extending beyond the side gussets;   first adhesive material on the first section and second adhesive material on the stepped construction, which attain adhesive states by heating to a temperature below the softening point temperature of the polymeric material;   the tube having a third section between the first section and the second section, wherein the first adhesive material and the second adhesive material are absent from the third section, and wherein the third section is free of adhesive;   the end of the tube being closed; and   the tube being folded along the third section without displacing or expelling adhesive from the third section in order to minimize adhesive contamination on surfaces of the tube, and the adhesive material on the stepped construction and the adhesive material on the first section meet in contact and under pressure below the third section and provide an adhesive-to-adhesive seal at the end of the tube.   
     
     
         2 . The bag of  claim 1 , wherein the tube is creased to provide a fold line along the third section, and the tube being folded along the fold line wherein the fold line is free of adhesive while the tube is folded along the fold line. 
     
     
         3 . The bag of  claim 1 , wherein the tube comprises a woven polymeric layer and a nonwoven polymeric layer. 
     
     
         4 . The bag of  claim 1 , wherein each of the side gussets includes a first gusset portion joining the first panel and a second gusset portion joining the second panel, wherein the first gusset portion and the second gusset portion extend the same length beyond the second section. 
     
     
         5 . The bag of  claim 1 , wherein each of the side gussets includes a first gusset portion joining the first panel and a second gusset portion joining the second panel, wherein the first gusset portion and the second gusset portion extend at different lengths beyond the second section. 
     
     
         6 . The bag of  claim 1 , wherein the tube comprises, a further stepped construction at a further end of the bag through which the bag is to be filled with contents, wherein the further stepped construction includes a further second section of the first panel, further portions of the side gussets extending beyond the further second section and a further portion of the second panel extending beyond the further portions of the side gussets;
 the first panel having a further first section and the further second section;   further adhesive material on the further first section and still further adhesive material on the further stepped construction, which attain adhesive states by heating to a temperature below the softening point temperature of the polymeric material;   the further end of the tube being closable after the bag has been filled with contents;   the tube having a further third section between the further first section and the further second section;   the tube being foldable along the third section after the bag has been filled with contents, for the further adhesive material and the still further adhesive material to meet in contact and under pressure while in their adhesive states to provide an adhesive-to-adhesive seal; and   the further adhesive material and the still further adhesive material being absent from the further third section, wherein the further third section between the further first section and the further second section is free of adhesive.   
     
     
         7 . A bag constructed of polymeric material and adapted to be closed and sealed after being filled with contents, comprising:
 a polymeric tube closed at one end to provide a bag having a closed end;   the bag having a first panel, a second panel and side gussets;   the first panel having a first section and a second section;   another end of the bag having a stepped construction through which the bag is to be filled with contents, wherein the stepped construction includes the second section, portions of the side gussets extending beyond the second section and a portion of the second panel extending beyond the portions of the side gussets;   first adhesive material on the first section and second adhesive material on the stepped construction, which attain adhesive states by heating to a temperature below the softening point temperature of the polymeric material;   the first panel having a third section between the first section and the second section;   the first adhesive material and the second adhesive material being absent from the third section, wherein the third section is free of adhesive;   said another end of the bag being closable and the bag being foldable along the third section without displacing or expelling adhesive from the third section in order to minimize adhesive contamination on surfaces of the bag, wherein the first adhesive material and the second adhesive material meet in contact and under pressure below the third section and provide an adhesive-to-adhesive seal.   
     
     
         8 . The bag of  claim 7 , wherein the bag is creased to provide a fold line along the third section, and the tube being foldable along the fold line. 
     
     
         9 . The bag of  claim 7 , wherein the bag comprises a woven polymeric layer and a nonwoven polymeric layer. 
     
     
         10 . The bag of  claim 7 , wherein each of the portions of the side gussets includes a first gusset portion joining the first panel and a second gusset portion joining the second panel, wherein the first gusset portion and the second gusset portion extend the same length beyond the second section. 
     
     
         11 . The bag of  claim 7 , wherein each of the portions of the side gussets includes a first gusset portion joining the first panel and a second gusset portion joining the second panel, wherein the first gusset portion and the second gusset portion extend at different lengths beyond the second section. 
     
     
         12 . A method for closing and sealing an end of bag taken from multiple bags each made of polymeric material, wherein the bag has a first adhesive material on a first section of a first panel, and has a second adhesive material on a stepped construction, which includes a second section of the first panel, portions of side gussets extending beyond the first panel and a portion of a second panel extending beyond the side gussets, the method comprising:
 heating the first adhesive material and the second adhesive material to their adhesive states, while conveying the bag along a hot air manifold after the bag has been filled with contents, and the bag closed and creased, wherein the first adhesive material and the second adhesive material are absent from a third section of the first panel, and wherein the third section is free of adhesive;   conveying the third section free of adhesive along a section of the hot air manifold, which minimizes adhesive contamination;   folding the bag along the third section without displacing or expelling adhesive from the third section, which minimizes adhesive contamination of surfaces of the bag; and   applying pressure to contact the first adhesive material and the second adhesive material and form an adhesive-to adhesive seal, which seals the end of the bag through which the bag has been filled with contents.   
     
     
         13 . The method of  claim 12 , comprising:
 heating the adhesive material to its adhesive state while having a dimension up to 3.81 cm (1.5 inches) in width on the first section of the first panel, and heating the adhesive material to its adhesive state while having a dimension up to 3.81 cm (1.5 inches) in width on the stepped construction of the bag.   
     
     
         14 . The method of  claim 12  comprising:
 conveying the bag continuously along the hot air manifold, while heating the adhesive material to its adhesive state. 
 
     
     
         15 . The method of  claim 12 , comprising:
 biasing the stepped construction of the bag toward the top wall of the hot air chamber while heating the adhesive material on the stepped construction to its adhesive state.   
     
     
         16 . The method of  claim 12 , comprising:
 spacing the adhesive material from the top wall of the hot air chamber to prevent contact therebetween while heating the adhesive material to its adhesive state.   
     
     
         17 . The method of  claim 12 , comprising:
 spacing the adhesive material from the back wall of the hot air chamber to prevent contact therebetween while heating the adhesive material to its adhesive state.   
     
     
         18 . The method of  claim 12 , comprising:
 creasing the bag by creasing along the third section of the first panel to provide a fold line, followed by conveying the bag continuously along the hot air manifold, while heating the adhesive material to its adhesive state; and   folding the bag along the fold line, wherein the adhesive material on the stepped construction meets the adhesive material on the first section of the first panel to form an adhesive-to-adhesive seal below the fold line.   
     
     
         19 . The method of  claim 12 , comprising:
 folding the bag along the fold line, wherein the adhesive material on the second panel is spaced from the fold line and forms an adhesive-to-adhesive seal with the adhesive material on the first section of the first panel below the fold line.   
     
     
         20 . A system for performing the method of  claim 12 , comprising:
 a bag taken from multiple bags each made of polymeric material and closed at one end, and the bag has first adhesive material on a first section of a first panel, and has second adhesive material on a stepped construction of the bag, and the stepped construction of the bag includes a second section of the first panel, portions of side gussets and a portion of a second panel, wherein the first adhesive material and the second adhesive material are absent from a third section of the first panel, and wherein the third section is free of adhesive;   a hot air manifold along which the bag is conveyed after the bag has been filled with contents and closed, and the bag creased to provide a fold line, wherein the hot air manifold heats the first adhesive material and the second adhesive material to their adhesive states;   a section of the hot air manifold along which the third section free of adhesive is conveyed, which minimizes adhesive contamination;   a blade to bias the stepped construction of the bag to follow along the manifold while the bag is being conveyed; and   a trailing end of the blade to fold the bag along its third section without displacing or expelling adhesive from the third section, which minimizes adhesive contamination of surfaces of the bag, and to be followed by a pinch closing apparatus applying clamping pressure to form an adhesive-to-adhesive seal, which seals the end of the bag through which the bag has been filled with contents.   
     
     
         21 . The system of  claim 20 , comprising:
 a creasing apparatus to crease the bag along a fold line, while the bag is being conveyed after the bag has been filled with contents through the end of the bag.   
     
     
         22 . The system of  claim 20 , comprising:
 a pinch closing apparatus following the trailing end of the blade and applying clamping pressure to form an adhesive-to-adhesive seal.