Patent ID: 7080584

Claim:
A method for perforating a non-woven sheet of fibers or filaments comprising the steps of: fixing on a perforated cylinder at least one insert, including, at one end, a plane surface, and provided with a recess that emerges in said plane surface, that has an inner surface and that has a sharp edge formed by the intersection of the inner surface with the plane surface; bringing the non-woven sheet into contact with the perforated cylinder and with the plane surface of the insert; bringing a perforating member, which is sized to be capable of simultaneously abutting against substantially the entire sharp edge of the insert, to the recess of the insert to locally compress fibers or filaments of the non-woven sheet between the perforating member and the sharp edge of the insert, whereby force between the perforating member and the insert causes the perforating member to translate along a translational axis; and driving the perforating member such that it rotates about an axis of the perforating member that is parallel to the translation axis for cutting out a portion of the non-woven sheet by shearing of the fibers or filaments of the non-woven sheet compressed between the perforating member and the sharp edge of the insert through the combined actions of rotation and pressure.