| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a film is very thin, and it is very difficult to fix a thin-walled portion to an intermediate portion of the film thickness when the thin-walled portion for tearing is formed by the heat-fusion using a heat roll and the half-cut by laser beams to form the thin-walled portion for tearing on a bag mouth portion. SOLUTION: A thin-walled working device of an easily-unsealable bag is unsealed by tearing a mouth portion. The working device has a pair of abrasive materials 24 and 24 to form narrow straight thin-walled portions 7 and 7 on each outer surface of face and back films 2 and 2 in slidable contact with each outer surface of the face and back films 2 and 2 at a tearing portion 6 of the bag. The thin-walled portion can be easily and correctly formed thereby at low cost. COPYRIGHT: (C)2004,JPO&NCIPI |
