METHOD FOR FORMING BAG WITH OPEN MOUTH ZIPPER TYPE GUSSET

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a zipper bag in which part of a gusset caught between fitting zipper elements is relatively thin against parts other than the wall of the bag and to provide a method for practicing in use by a conventional forming/filling/sealing apparatus without adding a remarkably large improvement in a method for forming the zipper bag with the gusset. SOLUTION: A zipper contour is intermittently provided to a carrier web and its thickness is thinner than that of a bag film and the carrier web is fitted on the bag film with a window cut piece arranged in the transverse direction in such a way that the non-contour part of the carrier web covers the window. The part of the bag film with the window covered with the carrier web is folded so as to form the gusset in the bag shape.