| 摘要 |
PURPOSE:To contrive to streamline the heat bonding between a container and a container cover and the formation of a score line for opening seal by a method wherein the thermally adherent resin layer applied onto the inner surface of the metal foil of a container cover is melted and at the same time the thermoplastic resin layer applied onto the outer surface of the metal foil is softened and removed. CONSTITUTION:Firstly, the peripheral wall part 10 of a container cover 2 consisting of a metal foil 6, the outer surface of which is covered with thermoplastic resin layer 7 and the inner surface of which is covered with thermally adherent resin layer 8, is fitted onto the opening part 3, onto which a reinforcing member 24 is coveringly bonded, of a container main body 1 against the holding part 14 of a lifter 11. Secondly, a tapered spindle 17 is lowered so as to insert the container cover 2 onto the container main body 1 by means of a cover-pressing mold 20. Thirdly, the metal foil 6 is heated by flowing electric current through a high frequency coil 15. Fourthly, by raising the spindle 17, the outer surface of the opening part 3 and the inner surface of the peripheral wall part 10 of the container cover 2 are bonded together through the adherent resin layer 8. At the same time, a projecting stripe 23, which is provided on the inner wall 19 of the pressing mold 20 is pressed into a softened thermoplastic resin layer 7 on the peripheral wall part 10 of the container cover 2 so as to remove only the thermoplastic resin layer 7 in order to form a score line 22. |
