Abstract: The invention relates to a metal cap, the thickness of the skirt of which is 0.06 to 0.4 mm, with at least one tearing ling which includes a cut or tear line and alternating transverse reliefs and external recesses, each recess ending in the tearing line or at least within 0.5 mm thereof, the thickness of the bottom wall of the tear line being 20 to 70% of the thickness of the skirt, and the tearing line having a bottom thickness which is at most equal to 70% of the thickness of the skirt. The invention also relates to a method of producing the cap. The invention is applicable to obtaining tearable tabs for metal caps which tabs tear entirely along the rear line provided without dangerous edges.

Abstract: According to the invention, a metallic product of a thickness less than or equal to 1 mm is compressed between a narrow elongated relief (2, 3) and an alternating succession of reliefs (10) and hollows (11) disposed opposite this narrow relief (2, 3), the differences in level between the said alternating reliefs (10) and hollows (11) being transverse in respect of the said narrow relief (2, 3), the compression stress being such that the minimum thicknesses of the said metallic product after compression are comprised between 0.01 and 0.15 mm. This method makes it possible to obtain tearing lines which have no injurious rough portions. The invention likewise relates to the products obtained and is particularly interesting in the field of packaging.

Abstract: The object of the invention is an aluminium or an alloy closure capsule adapted to be crimped onto the neck of a bottle and of which the ring comprises a shoulder, the skirt of this capsule comprising a retaining ring or peripheral rib which, after the capsule has been crimped onto the neck, will define with the portion of the skirt covering the top edge of the said shoulder of the neck an annular groove permitting guidance of a blade for cutting the capsule, and also a line of weakness consisting of a thinned peripheral zone situated in the bottom of the said groove. The invention also relates to the method of producing this capsule which is used for any closure of a bottle which has to have its capsule removed by means of a knife.