Open-easiness closed housing and its production manner

摘要

PURPOSE:To facilitate the interlayer release of a multilayer container main body and to select an arbitrary seal width condition at the time of heat-sealing, by providing an annular slit to the flange part inside a heat seal part and forming a recessed seal layer to the outer end of the heat seal part under pressure through a lid material. CONSTITUTION:The multilayer sheets 1, 2 constituting a container is constituted of a material making the interlayer bonding strength of said sheets 1, 2 lower than the heat seal strength of a lid material 4 and the multilayer container main body and generating release between the layers of the multilayer container main body when the lid material is opened to make the opening of the lid material easy. A recessed seal part 10 is formed to the outer end of the heat seal part of a flange part 3. When a tab part 8 is raised, release is started between the innermost layer 1 and the layer 2 brought into contact therewith from the part of the recessed seal layer 10 and, in succession thereto, the innermost layer of the outer edge of the heat seal part is cut and release advances between the innermost layer 1 and the layer 2 brought into contact therewith and the innermost layer is released up to the part of a slit 6 to release the lid material. Therefore, even when the lid material and the multilayer container main body are heat-sealed in a hermetically sealed and hardly released state, the container can be easily opened.