| 摘要 |
A dispensing closure for a product container comprises a plastic closure body. The closure body has a top wall provided with a dispensing opening which is arranged in line with a dispensing passage of the container. The closure comprises a self-closing valve embodied as a membrane made of a plastic foil having a thickness t. The membrane has a valve portion, which in use can assume an open position under influence of product pressure, and an attachment portion surrounding the valve portion. The attachment portion of the valve is sealed to an annular support surface integrally formed in the closure body along the periphery of the opening or being formed on a plastic annular insert part that is connected to the closure body along the periphery of the opening. The seal between the attachment portion and the support surface comprises an annular groove and an inner annular seal zone adjoining the annular groove on a radial inner side, said annular groove being recessed in the support surface and having a depth that is 2 - 5 times the thickness of the membrane. |
