| 摘要 |
PROBLEM TO BE SOLVED: To provide a lid member having adaptability to printing, high barrier property, sealability, unsealability and a retort adaptability of high rate of conversion into paper. SOLUTION: This lid member is composed of a dropping lid 24 comprising a top plate 23, a peripheral wall 22 vertically arranged at a peripheral edge of the top plate such that it can be in close contact with an inner wall of a barrel section of a cylindrical container, and a seal flange 21 arranged at an upper edge of the peripheral wall outwardly in parallel with the top plate, a top plate sheet section 25 where an end edge is positioned to the inside of an end edge of the seal flange to cover the entire top plate and form a space 26 between the sheet section and the top plate, and a lid material sheet section 27 mounted on the top plate sheet section with its peripheral edge being located outwardly from the peripheral edge of the top plate sheet section. When the peripheral edge of the lid material sheet, the peripheral edge of the top plate sheet, and the seal flange of the dropping lid member are heat welded the lid material sheet and the seal flange are directly heat welded near the end edge of the seal flange, and the lid material sheet, the top plate sheet and the seal flange are heat welded to each other near the peripheral wall of the seal flange. |
