Perforation anvil

A method of perforating a web comprising,

• providing a web,
• passing the web through a nip, wherein the nip is defined as a contact point between a cutting edge and an anvil surface, the cutting edge comprising a portion of a knife roll and the anvil surface comprising a portion of an anvil roll, the anvil roll being adapted to rotate about an anvil roll axis, the knife roll being adapted to rotate about a knife roll axis, the anvil surface comprising a plurality of grooves separated by a plurality of lands, the plurality of grooves being angled and having variable groove widths, and
• perforating the web in the nip at a first machine direction cutting position by pressing the cutting edge against the web and the anvil surface to cut the web at the lands and to maintain the web at the grooves.

An anvil roll comprising an anvil surface wherein the anvil surface includes a plurality of angled grooves having a variable cross-machine direction groove width, wherein the anvil surface is part of an insert and wherein the anvil surface is made of cobalt sub-micron HIP carbide and wherein the grooves have a groove angle of about 25 degrees to 45 degrees.

A perforation apparatus comprising,

• a knife roll adapted to be rotated about a knife roll axis, the knife roll comprising at least one cutting edge;
• an anvil roll adapted to be rotated about an anvil roll axis, the anvil roll axis being parallel with the knife roll axis, the anvil roll having an outer surface wherein at least a portion of the outer surface defines an anvil surface which includes a plurality of angled grooves, wherein a majority of the grooves have a variable groove width, and
• a cutting nip defined by the point wherein the cutting edge contacts the anvil surface.