Abstract: A container such as a metal top can containing a liquid to be dispensed by perforating the can top has an annular metal top having a concentric opening sealed with an easily perforatable thin film material. The thin film material extends across adjacent to the undersurface of the annular metal top and is sandwiched between the container top and the can body at the rim in a usual rim bead crimping operation, which leaves a projecting edge portion of the thin film outside of the rim. This edge of the film is then melted away by a hot sleeve or by spinning the sealed can relative to a hot element. The thin film material, which may be a polyester plastic, is selected to be sufficiently strong to protect the container contents during normal handling yet is more readily perforatable than the container top itself would be.

Abstract: A container such as a metal top can containing a liquid to be dispensed by perforating the can top has an annular metal top having a concentric opening sealed with an easily perforatable thin film material. The thin film material extends across adjacent to the undersurface of the annular metal top and is sandwiched between the container top and the can body at the rim in a usual rim bead crimping operation, which leaves a projecting edge portion of the thin film outside of the rim. This edge of the film is then melted away by a hot sleeve or by spinning the sealed can relative to a hot element. The thin film material, which may be a polyester plastic, is selected to be sufficiently strong to protect the container contents during normal handling yet is more readily perforatable than the container top itself would be.