Abstract: A closure 10 for a container, comprises a substantially circular base 20, a skirt 30 extending from the periphery thereof, a bore seal 50 in the form of an annulus and a rib 70 lying on the surface of the base 20 in a substantially radial direction and in contact with the radially inner surface of the bore seal 50 at one end for transferring any movement of the center of the base 20, relative to the skirt 30, to the bore seal 50 such that the bore seal 50 is pulled radially inward to allow venting of excess pressure within the container, wherein the end of the rib 70 in contact with the radially inner surface of the bore seal 50 is substantially thinner, in a plane parallel to the base 20, than the other end of the rib 70.

Abstract: A plastic closure for a container is provided. The closure includes a top plate with a side skirt depending from the periphery thereof. A sealing strip depends from the top plate and is adapted to sealingly engage a container neck finish. The closure also comprises an abutment member including a guide surface for guiding the sealing strip towards the neck finish as the closure is applied, to increase the strength of the seal. The guide surface includes a guide member that projects from the abutment member, thereby minimizing friction between the strip and the abutment member. The sealing strip is inclined radially towards the neck finish to improve the sealing effect.