Abstract: A system for forming and mounting end closures for peel-top containers, each closure including a peelable sealing membrane, with a folded pull tab, and a separate plastic overcap. The individual sealing membranes are cut from a continuous web and deposited directly on the open ends of cans or containers being fed in a continuing line. Each membrane is retained in properly oriented association with the corresponding container, by adhesive tacking or through a partial vacuum generated within the container, until such time as the container supported membrane is engaged by a chuck to effect a positive sealing of the membrane to the container. After a sealing of the membrane to the container, the container proceeds through a cycle wherein the tab on the membrane is laterally bent, the overcap is applied, and the container with completed end closure is discharged.