Closure Bag with Reinforced Handles

Abstract

A method of forming bag precursors and individual bags from a supply of polymer sheeting is disclosed. The method includes the steps of folding a polymer sheet in half to form a bottom edge at the fold, two sheet faces, and a top edge opposite the fold; inserting a pre-closed zipper into the top edge between the two folded sheets and fixing the zipper to the inside surfaces of each sheet and with a header space between the zipper and the top edge of the sheet; thereafter opening the zipper and separating the sheets at the zipper; maintaining the open zipper portions and sheets in alignment and applying reinforcing patches to the interior of each sheet at the opening; and thereafter reclosing the aligned zipper portions

1 . A method of forming bag precursors and individual bags from a supply of polymer sheeting, the method comprising the steps of:
 folding a polymer sheet in half to form a bottom edge at the fold, two sheet faces, and a top edge opposite the fold;   inserting a pre-closed zipper into the top edge between the two folded sheets and fixing the zipper to the inside surfaces of each sheet and with a header space between the zipper and the top edge of the sheet;   thereafter opening the zipper and separating the sheets at the zipper;   maintaining the open zipper portions and sheets in alignment and applying reinforcing patches to the interior of each sheet at the opening; and   thereafter reclosing the aligned zipper portions.   
     
     
         2 . A method according to  claim 1  further comprising cutting the handle openings through the reinforcing patches following the reclosing step. 
     
     
         3 . A method according to  claim 2  comprising die cutting the handle openings. 
     
     
         4 . A method according to  claim 2  comprising cutting and sealing the sheets perpendicularly to the top and bottom edges to form individual bags. 
     
     
         5 . A method according to  claim 4  comprising heat cutting and sealing the sheets. 
     
     
         6 . A method according to  claim 5  comprising cutting and sealing the sheets between the patch handle portions to define one handle per finished bag. 
     
     
         7 . A method according to  claim 1  comprising adding patches that have at least one dimension smaller than the header space defined by the zipper and the top edge 
     
     
         8 . A method according to  claim 1  comprising:
 folding a moving supply of polymer sheeting; and 
 thereafter carrying out the zipper inserting, zipper opening and patch applying steps on the folded moving supply of polymer sheeting 
 
     
     
         9 . A method according to  claim 1  comprising inserting a press-to-close zipper with pre-closed male and female profile portions, and fixing each of the profile portions to one of the respective folded sheets. 
     
     
         10 . A method of forming bag precursors and individual bags from a supply of polymer sheeting, the method comprising the steps of:
 folding a moving thermoplastic polymer sheet in half over a triangular frame to form a bottom edge at the fold, two sheet faces, and a top edge opposite the fold;   inserting a pre-closed zipper into the top edge between the two moving folded sheets and heat sealing the zipper to the inside surface of each moving sheet and with a header space between the zipper and the top edge of the moving folded sheets;   thereafter opening the zipper and separating the moving sheets at the zipper;   maintaining the open zipper portions and sheets in alignment and applying reinforcing patches to the interior of each sheet at the opening; and   thereafter reclosing the aligned zipper portions on the moving sheets.   
     
     
         11 . A method according to  claim 10  further comprising forming a die cut opening in the precursor at the patch positions. 
     
     
         12 . A method according to  claim 10  wherein the step of heat sealing the zipper comprises applying an amount of heat that is sufficient to fasten the zipper to the sheets, but without melting the male and female portions of the zipper into one another. 
     
     
         13 . A method according to  claim 10  wherein the step of opening the zipper comprises separating the moving sheets and opening the zipper with an opening arm as the sheets and zipper pass over and are directed by at least one guide. 
     
     
         14 . A method according to  claim 10  wherein the step of maintain the sheets and the zipper in alignment comprises:
 directing the moving sheets over a bag opening pin that keeps the sheets separated while the reinforcing patches are being inserted by the patch heat sealer; and 
 directing the moving sheets over pair of guide pins to help maintain the moving sheets oriented properly with respect to a patch heat sealer. 
 
     
     
         15 . A method according to  claim 10  wherein the step of reclosing the aligned zipper comprises directing the moving sheets and zipper through a set of pinch rollers. 
     
     
         16 . A method according to  claim 10  comprising collecting the bag precursors on a stock roll for later separation. 
     
     
         17 . A method according to claim  20  comprising separating the bag precursors to form the final bag. 
     
     
         18 . In a method of forming bag precursors and individual bags from a supply of polymer sheeting by folding a polymer sheet in half to form a bottom edge at the fold, two sheet faces, and a top edge opposite the fold; and inserting a pre-closed zipper into the top edge between the two folded sheets and fixing the zipper to the inside surfaces of each sheet and with a header space between the zipper and the top edge of the sheet;
 and forming a die cut opening in the header space;   the improvement comprising:   opening the zipper and separating the sheets at the zipper;   maintaining the open zipper portions and sheets in alignment and applying reinforcing patches to the interior of each sheet at the opening; and   thereafter reclosing the aligned zipper portions.