Patent ID: 8679391

Claim:
A method for making apertures in a web, said method comprising: a. providing a precursor web material having a first side and a second side; b. providing a pair of counter-rotating, intermeshing rollers which define a nip therebetween, said rollers comprising: (1) a first roller having a first axis about which said first roller rotates and said first roller comprises circumferentially-extending ridges and grooves that are aligned perpendicular to said first axis, wherein said ridges have a base located where the ridges extend outward from the surface of the first roller, and said ridges extend radially outward to a tip, wherein said ridges have a generally triangular cross-section having a cross-sectional width which is larger at the base of the ridges and the ridges taper to a smaller width at the tip of said ridges; and (2) a second roller having a second axis about which said second roller rotates, said second roller comprising teeth, said teeth each having a base where they are joined to said second roller and a single tip, said teeth being tapered from said base to said tip, wherein the base of each tooth has a cross-sectional length dimension measured in a direction perpendicular to the second axis, which is greater than a cross-sectional width dimension measured parallel to the second axis; and c. moving said web material through the nip between said counter-rotating, intermeshing rollers; d. wherein apertures are formed in said precursor web material as said teeth on one of said rollers intermesh with grooves on the other of said rollers, wherein the tip of a tooth forms a single aperture in said precursor web material.