摘要 |
A package obtained by superposing a sheetlike lid through the medium of a hot melt layer, on a tray provided along the edge of a recess therein with a sheetlike flange part, and then heat sealing the tray and the sheetlike lid at the sheetlike flange part. The heat sealed portion formed between the sheetlike flange part of the tray and the sheetlike lid includes at least one primary joined portion having one of the sheetlike parts strongly pressed down and partially buried in the other sheetlike part, and at least one secondary joined portion adjacent said primary joined portion having said sheetlike parts pressed down less strongly against each other than in the primary joined portion. The secondary portion is at least on the inner side of the primary joined portion toward the tray recess, relative to the direction of the cross section of the heat sealed portion, thus serving to provide protection for the primary joined portion. |