Method and apparatus for deforming a web
Methods and apparatuses for deforming a web are disclosed. In one embodiment, the method involves feeding a web into a nip that is formed between at least two intermeshing rolls. The rolls are configured for deforming a web with at least two sets of deformations that are oriented in different directions relative to the surfaces of the web.
1. A process for deforming a web using an apparatus, the process comprising feeding a precursor web into a nip that is formed between two intermeshing rolls comprising:
a) a generally cylindrical first roll, said first roll having a surface, a circumference, and an axis, said first roll comprising:
a plurality of ridges and grooves extending around the circumference of the roll on the surface of the roll, wherein said ridges have a top surface and said grooves have a bottom surface; and
a plurality of first spaced apart forming elements extending outwardly from the top surface of said ridges, said first forming elements having tips, wherein the top surface of said ridges are disposed between the tips of said forming elements and the bottom surface of said grooves; and
b) a generally cylindrical second roll, said second roll having a plurality of second discrete forming elements on its surface, said second forming elements having tips, and
when said web is fed into said nip, the tips of said second forming elements extend inward toward the axis of said first roll to a depth beyond the top of at least some of the ridges on said first roll, and said web is deformed: (i) by said first forming elements in a plurality of spaced apart first locations to form a plurality of spaced apart first features; and (ii) by said second forming elements in different locations than said first locations to form a plurality of spaced apart second features, wherein said second features are distributed between said first features.
2. The process of claim 1 wherein the second roll further comprises:
a plurality of ridges and grooves extending around the circumference of the roll on the surface of the second roll, wherein said ridges have a top surface and the grooves have a bottom surface; and
the second forming elements are spaced apart and extend outwardly from the top surface of said ridges on the second roll, and the top surface of said ridges are disposed between the tips of said second forming elements and the bottom surface of said grooves in said second roll, directionally relative to the axis of said second roll.
3. The process of claim 1 wherein the first roll also forms a nip with an additional roll, said first nip and said second nip are formed on a common roll and the nip between the first roll and the additional roll comprises a first nip, and the nip between the first roll and the second roll comprises a second nip, wherein said precursor web is:
a. first deformed by the first forming elements on the first roll in the first nip between the first roll and the additional roll; and
b. thereafter deformed by the second forming elements on the second roll in the second nip between the first roll and the second roll.
4. The process of claim 1 wherein the first roll also forms a nip with an additional roll, said first nip and said second nip are formed on a common roll and the nip between the first roll and the second roll comprises a first nip, and the nip between the first roll and the additional roll comprises a second nip, wherein said precursor web is:
a. first deformed by the first and second forming elements on the first and second forming rolls in the first nip; and
b. thereafter further deformed in the first regions by the first forming elements on the first roll in the second nip between the first roll and the additional roll.