CPC B26F 1/10 (2013.01) [B26D 1/385 (2013.01); B26D 1/626 (2013.01); B26D 7/1854 (2013.01); B26D 7/1863 (2013.01)] | 23 Claims |
1. A method of perforating a web, the method comprising:
rotating a cylinder about a longitudinal cylinder axis to form a boundary layer of air flow, the cylinder comprising an outer circumferential surface, wherein a plurality of anvil blocks are disposed in respective recesses of the cylinder and extend by anvil block heights beyond the outer circumferential surface of the cylinder, wherein each of the anvil blocks comprises a plurality of segments that are offset from each other along the longitudinal cylinder axis to define cavities between the anvil block heights of adjacent ones of the plurality of anvil blocks, the cavity comprising a low pressure zone, and wherein each of the plurality of anvil blocks comprises an anvil bead protruding by an anvil bead height therefrom, wherein the anvil bead extends beyond an outer surface of each anvil block, wherein the anvil bead extends longitudinally and continuously along the outer surface of each anvil block, wherein a first half of the anvil bead is positioned on a first half of the anvil block in a rotation direction, and wherein a second half of the anvil bead is positioned on a second half of the anvil block in the rotation direction;
operatively engaging a blade with the anvil beads, wherein the blade is parallel to the longitudinal cylinder axis, and wherein the blade comprises a plurality of teeth;
feeding a web between the anvil bead and the blade while the blade cooperates in contacting relationship with the anvil bead;
perforating the web to form a shaped line of weakness;
generating debris from perforating the web; and
collecting the debris such that the debris is drawn to the low pressure zone of the cavity.
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