| 摘要 |
A package (19) comprises: a packaging container (11) having a containing section (14) open at the top and formed by a bottom (12) and by a peripheral wall (13) rising from the peripheral edge of the bottom (12), the packaging container (11) further having a flange (15) formed thereon, the flange (15) being provided along the entire circumference of the peripheral wall and protruding outward relative to the containing section from the upper end of the peripheral wall; a contained object (20) contained within the containing section and producing vapor when heated; and a top seal (21) joined to the flange along the entire circumference thereof to seal the inside of the containing section. The packaging container has a curved section (C) where a part of the peripheral wall is curved toward the containing section. A maximum deformation point (M) is formed in the curved section, the maximum deformation point (M) being the point where the deformation of the peripheral wall is maximum when pressure within the containing section increases to deform the top seal. The deformed top seal and the flange are pulled in the direction in which the deformed top seal and the flange are separated from each other, and when pressure within the containing section exceeds a set value, the top seal is separated from the flange at the maximum deformation point to release vapor within the containing section. |
