| 摘要 |
An easy-opening closure is provided for hermetic sealing of the open end of a packaging container. The closure includes a composite end for being double-seamed to the container and having an interior ledge portion defining a central opening through the closure. The composite end includes at least two polymer layers defining a predetermined peel strength for delamination and a formable substrate layer bonded to the bottom one of the polymer layers and adapting the end member to be double-seamed to the container. The end member has a notch cut into the top polymer layer in the ledge portion which is spaced from and surrounds the central opening. A lidding member covers the central opening and has a portion overlapping and bonded to the top polymer layer in the ledge portion of the end member to define a predetermined bond strength greater than the peel strength of the two polymer layers of the end member. With this construction, the force required to open the closure from the inside of the container is greater than the force required to open the closure from the outside of the container since the closure is easily-opened by upward pulling of the bonded overlapping portions of the lidding member to cause delamination and peeling of the portion of the top polymer layer bonded to the lidding member from the bottom polymer layer beginning at the notch and continuing to the central opening.
|
