| 摘要 |
The method comprises: a) supplying a strip or sheet of aluminium alloy, known to those skilled in the art as a "textured" strip or sheet, typically coated on at least one of its two faces, generally the face intended to be on the inside of the cap, with a coat of deep-drawing boundary lubricant, b) a first operation of cutting into disks known as blanks, c) a step of deep drawing said metal in blank form, in one or more passes typically using a deep-drawing boundary lubricant, so as to form a drawn pre-form, comprising a head and a skirt, typically exhibiting symmetry of revolution about an axial direction, d) a step of degreasing said drawn preform, which step is intended typically to eliminate remains of boundary lubricant so as to form a degreased preform that can be lacquered, e) a possible step of applying a protective and decorative lacquer, and is characterized in that it comprises, after the deep-drawing step and prior to the lacquering step, at least one ironing step consisting in passing the drawn preform through ironing rings in order to stretch out and thin the metal. The invention also relates to a closure cap thus produced. Advantages: the textured appearance is maintained over the entire surface of the head of the cap whereas a smooth or bright appearance is obtained over the entire height of the skirt or wall of the cap. |
