EASILY OPENABLE PACKAGING BAG AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To form a processed parts for easy opening at the positions same on both sides of a packaging bag, to provide therewith easy openability wherein the direction of opening is fixed and to make excellent the preservability of contents by a method wherein the processed parts for easy opening that do not penetrate through laminnated films are formed at both sides of a part to be opened of the packaging bag with a laser beam applied onto one side of the bag. SOLUTION: With a high-powered laser beam applied to one side of a laminated film constituting a packaging bag 1, a through hole 5 is formed at a plastic film layer 2 whereat the laser beam is easily absorbed. After penetrating through a plastic film layer 3 whereat the laser beam is hardly absorbed at the same side and the plastic film layer 3 of hardly absorbing the laser beam at the opposite side of the packaging bag 1, the laser beam forms a through hole 6 at the plastic film layer 2 of easily absorbing the laser beam at the opposite side. Therefore, processed parts in perforations for easy opening can be formed in the same directions at opposite positions on the plastic film layers 2 of easily absorbing the laser beam at both sides of the packaging bag 1, thus contents become preservable excellently.