METHOD AND MACHINE FOR MAKING A STOPPER FOR THE NECK OF A CONTAINER, AND STOPPER AS PRODUCED BY THIS METHOD

摘要

This method makes a stopper (1) from a tubular skirt (12) suitable for enclosing a neck of a container and provided both with means of permanent retention around the neck and means of removable attachment to the neck. The method involves moving, relative to each other, the skirt and a blade (110) in rotation about the axis (X-X) of the skirt in such a way that the blade cuts into the skirt a peripheral weakening line comprising through slots and, between these slots running around the periphery of the skirt, breakable bridges which connect, in the axial direction, a non-removable part of the skirt that has retention means, to a removable part of the skirt which has means of attachment. In order to improve the method in a simple and economical manner, the skirt and the blade are rotated relative to each other around an angular path strictly greater than 360° while gradually modifying the relative axial position between the skirt and the blade by an axial translation (T). The weakening line thus assumes the form of a helix whose two extreme ends define between themselves a non-breakable segment that permanently connects together the removable and non-removable parts of the skirt.