PROBLEM TO BE SOLVED: To make four or six sheets superposed packaging film part easily unsealable while appropriately keeping the rigidity and preventing the packing film during the bag-making process from cracking, by providing a thick-and-thin face part in a fine sand state at only a part which can not be torn easily. ;SOLUTION: A thin film part is embossed in a fine sand state in a packaging film 1 along the vertical body seal part 2 to form a thick-and-thin face part 11. This thic-and-thin face part 11 may be formed over the whole area of the body seal part 2 or may be formed along the inner end of the seal part 2. The notch formed at the lower part of the upper seal part 3 area is used as the starting point for the tearing line and the part near the body from the lower end of the seal part 3 is unsealed laterally along the tearing and unsealing line L-L. In this time, the upper heat seal part 3 in which four sheets of superposed packaging materials are positioned, can be almost linearly torn and unsealed by interposing a thin film part easily torn in the thick-and-thin face part 11.;COPYRIGHT: (C)1998,JPO
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