| 摘要 |
PURPOSE:To prevent milk from spilling when a pack is opened by forming the pack in such a manner that the inner pressure of the pack is under a slightly reduced condition from atmospheric pressure at room temperature. CONSTITUTION:When a container member (a'), for which milk is packed in a container main body (a), and a lid member (b'), which is placed over the container member (a'), are conveyed and stop at a sealing part (j), the container main body (a) is fitted in a storage port 15 on a lower die 10 by ascending of the lower die 10. A soft drum part 4 is pressed by an arc shaped head part 17 of a pressing bar 18 for a pressing member unit (p), which is provided on a tilted surface 16 of the storage port 15. By doing this, the soft drum part 4 is depressed and deformed. Under this condition, an upper die 11 descends, and the lid member (b') is pressed to a collar part 2 of the container main body (a) by a heated sealing projecting strap 30 which is provided on the lower surface of the upper die 11, and the lid member (b') is annularly sealed. When the sealing is completed, the upper die 11 ascends, the lower die 10 descends, and the drum part 4 of the container main body (a) is released from pressing by the pressing bar 18. Therefore, the inwardly deformed drum part 4 returns to the original state. Since the internal volume of the sealed container main body (a) is increased by a portion which is deformed by pressing, the inside of the container main body (a) gives a slightly pressure reduced condition from atmospheric pressure. |
