Cap for an aluminium can

摘要

In the case of a can cap made of thin aluminium-alloy sheet which is beaded in a leak-tight manner to a can made of thin aluminium-alloy sheet and forms a frustoconical part that tapers upwards, the cap is provided with a notch to form a separable part and an operating tab is attached to this part. The sheet from which the cap is made has a yield strength of 24 to 29 kgf/mm<2> and an elongation equal to or greater than 6%, the opening ratio, defined as the ratio of the area bounded by the notch to the total area of the cap being equal to or greater than 60%. The notch is in the form of a ring and is at a distance of at least 1 mm from the bottom edge of the frustoconical part of the cap and the inner radius of curvature of the edge is equal to or less than 0.5 mm.