COMPOSITE CLOSURE HAVING AN INSERT WITH A PERIPHERAL CURL

摘要

A composite closure (10) for a standard 40 mm opening is configured to form a cavity (40) to house a curl (52) of the insert disc. The shell (12) of the closure extends vertically to provide the cavity, and a transition (36) of the shell is thickened to provide strength for the shell's retaining ring. Employing a curl on the insert disc enables the insert disc to be formed of conventional coated steel. Because the channel of the retaining ring (30) is not semi-toroidal or like shape, the container may be formed by a blow trim process without an extra reaming step for preparing the internal portion of the container neck.