| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealing method which is simple, and can be produced at a low cost, and is easily openable by a method wherein the surface of a flange part of a plastic container main body, by which a lid member is heat- sealed, a downward slope from the internal edge to the external edge, is provided at a location where the container main body is opened upward, and the downward slope is made a surface to be heat-sealed. SOLUTION: As a surface to be heat-sealed 3 where a lid member is heat- sealed on a flange part 1, on the surface of the flange part 1, a slope which descends from the internal edge 7 (closer to a container main body) to the external edge 5 (away from the container main body), is provided. Or, a protruding part of which the cross sectional surface has a triangular protuberance, is provided, and the external slope is made the surface to be heat-sealed 3. By heat-welding the lid member on these slopes, the peeling strength from the internal side of the main body lid becomes larger than that from the external side, and an unsealing from the external side becomes easier. The material of the container main body may be anything as long as it is a material which is welded on the opening flange part 1 with the container main body, and a special processing is not required. |
