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.

What is claimed is: 
     
         1 . 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.   
     
     
         2 . The method of  claim 1 , 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.   
     
     
         3 . The method of  claim 1  comprising:
 conveying the bag continuously along the hot air manifold, while heating the adhesive material to its adhesive state. 
 
     
     
         4 . The method of  claim 1 , 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.   
     
     
         5 . The method of  claim 1 , 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.   
     
     
         6 . The method of  claim 1 , 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.   
     
     
         7 . The method of  claim 1 , 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.   
     
     
         8 . The method of  claim 1 , 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.   
     
     
         9 . A system for performing the method of  claim 1 , 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.   
     
     
         10 . The system of  claim 9 , 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.   
     
     
         11 . The system of  claim 9 , comprising:
 a pinch closing apparatus following the trailing end of the blade and applying clamping pressure to form an adhesive-to-adhesive seal.