| 摘要 |
<p>A method of closing a container with a "roll-on" type of screw threaded closure, comprises taking a closure blank with a moulded resilient gasket on the inner face of the end wall, the gasket being profiled so as to have a central circular panel and an adjoining annular bead which, when viewed in an axial cross-section through the closure, consists of a hump projecting above the level of the central panel of the gasket and terminating just short of the skirt of the closure, with the centre of area of the hump disposed closer to the skirt of the closure than is the centre of the base line of the hump. The closure and container neck are depressed axially together to close the bottle-neck and to compress the hump-shaped bead of the closure axially and to deform the hump-shaped bead radially outwardly towards the skirt of the closure. The closure is reformed y diametral contraction of the root of the closure skirt above the threads of the container neck under "tight" reform conditions so that the bead of the gasket acts as at least a partial side seal against the upper part of the neck of the container. The closure skirt is then deformed radially inwardly against the threads of the bottle neck to for threads in the closure skirt corresponding to the threads on the container neck.</p> |
