Method for making a shaped nonwoven
A method for making nonwoven fabric. The nonwoven fabric can include three-dimensional features that define a microzone comprising a first region and a second region. The first and second regions can have a difference in values for an intensive property. The nonwoven further has a plurality of apertures, wherein at least a portion of the aperture abuts at least one of the first region and the second region of the microzone.
1. A method for making an apertured nonwoven fabric, the method comprising the steps of:
a. providing a fiber laydown surface in the form of a first side of a continuous belt, the continuous belt comprising a reinforcing member and a pattern of three-dimensional raised elements extending outwardly from the reinforcing member on the first side of the continuous belt, the continuous belt further comprising a plurality of openings, each opening allowing fluid communication between the first side of the continuous belt and a second side of the continuous belt;
b. providing a fiber melt spinning apparatus above the first side of the continuous belt and a vacuum source below the second side of the continuous belt, wherein the continuous belt is moved in a machine direction between the fiber spinning apparatus and the vacuum source;
c. providing a compaction nip between a first pair of rolls, at least one of the rolls of the first pair of rolls being heated;
d. providing an aperturing nip between a second pair of rolls;
e. providing a bonding operation comprising a calendar nip;
f. melt spinning fibers from the melt spinning apparatus onto the fiber laydown surface as the continuous belt moves in the machine direction over the vacuum source to collect the melt spun fibers onto the fiber laydown surface, the collected melt spun fibers forming a nonwoven web having three-dimensional features, each three-dimensional feature defining a microzone comprising a first region and a second region, the first and second regions having a difference in values for an intensive property, wherein the intensive property is one or more of thickness, basis weight, and volumetric density; wherein in each microzone, the second region comprises a portion of the nonwoven web that is formed over the three-dimensional raised element of the continuous belt, and the first region comprises the remainder of the nonwoven web within the particular microzone;
g. moving the continuous belt in the machine direction through the compaction nip to create a compacted nonwoven web, the compaction nip being sized such that the second region of the microzone is compressed and heated to at least partially melt bond at least a portion of the fibers of the second region into frangible bond areas;
h. moving the compacted nonwoven web in the machine direction through the calendaring nip to create a compacted and calendared nonwoven web, the calendaring nip being sized to contact the compacted nonwoven web and impart infrangible thermal bonds to at least some of the fibers therein; and
i. moving the compacted and calendared nonwoven web through the aperturing nip, the aperturing nip forming an aperture at, or directly adjacent to, at least one of the frangible bond areas; and
j. rolling the compacted and calendared nonwoven web into a rolled form.
2. The method of claim 1 , wherein a distal surface of the raised elements have a two-dimensional shape having an aspect ratio of between 2 and 10.
3. The method of claim 1 , wherein the fiber spinning apparatus is a spunbond apparatus.
4. The method of claim 1 , wherein the reinforcing member is a woven reinforcing member and the three-dimensional raised elements comprise cured polymeric resin.
5. The method of claim 1 , wherein the frangible bonds have an aspect ratio of between 2 and 10.
6. The method of claim 1 , wherein the relatively infrangible thermal bonds have an aspect ratio of 1.
7. The method of claim 1 , wherein each roll of the second pair of rolls comprise circumferentially extending ridges that inter-engage in the nip.
8. The method of claim 1 , wherein the aperture is formed adjacent to the frangible bond.
9. The method of claim 1 , wherein the aperture has a perimeter, and a first portion of the perimeter comprises free fibers and a second portion of the perimeter comprises the partially melt bonded fibers of the frangible bond area.
10. The method of claim 1 , wherein the continuous belt comprises a second pattern of three-dimensional raised elements, the second pattern of three-dimensionally raised elements being visually distinct from the first pattern of three-dimensional raised elements.
11. The method of claim 1 , wherein the bonding operation is through-air bonding.
12. The method of claim 1 , wherein the bonding operation is calendar point bonding.
13. A method for making an apertured nonwoven fabric, the method comprising the steps of:
a. providing a fiber laydown surface in the form of a first side of a continuous belt, the continuous belt comprising a reinforcing member, a first pattern of discrete three-dimensional raised elements extending outwardly from the reinforcing member on the first side of the continuous belt, and a second pattern of curvilinear three-dimensional raised elements extending outwardly from the reinforcing member on the first side of the continuous belt, the curvilinear three-dimensional raised elements forming a closed figure, the continuous belt further comprising a plurality of openings, each opening allowing fluid communication between the first side of the continuous belt and a second side of the continuous belt;
b. providing a fiber melt spinning apparatus above the first side of the continuous belt and a vacuum source below the second side of the continuous belt, wherein the continuous belt is moved in a machine direction between the fiber spinning apparatus and the vacuum source;
c. providing a compaction nip between a first pair of rolls, at least one of the rolls of the first pair of rolls being heated;
d. providing a aperturing nip between a second pair of rolls;
e. providing an calendaring nip between a third pair of rolls;
f. melt spinning fibers from the melt spinning apparatus onto the fiber laydown surface as the continuous belt moves in the machine direction over the vacuum source to collect the melt spun fibers onto the fiber laydown surface, the collected melt spun fibers forming a nonwoven web having three-dimensional features, each three-dimensional feature defining a microzone comprising a first region and a second region, the first and second regions having a difference in values for an intensive property, wherein the intensive property is one or more of thickness, basis weight, and volumetric density; wherein in each microzone, the second region comprises a portion of the nonwoven web that is formed over the discrete three-dimensional raised element of the continuous belt, and the first region comprises the remainder of the nonwoven web within the particular microzone;
g. moving the continuous belt in the machine direction through the compaction nip to create a compacted nonwoven web, the compaction nip being sized such that the second region of the microzone is compressed and heated to at least partially melt bond at least a portion of the fibers of the second region into frangible bond areas;
h. moving the compacted nonwoven web in the machine direction through the calendaring nip to create a compacted and calendared nonwoven web, the calendaring nip being sized to contact the compacted nonwoven web and impart infrangible thermal bonds to at least some of the fibers therein;
i. moving the compacted and calendared nonwoven web through the aperturing nip, the aperturing nip forming an aperture at, or directly adjacent to, at least one of the frangible bond areas; and
j. rolling the compacted and calendared nonwoven web into a rolled form.
14. The method of claim 13 , wherein a distal surface of the raised elements have a two-dimensional shape having an aspect ratio of between 2 and 10.
15. The method of claim 13 , wherein the closed figure is in the shape selected from the group consisting of heart-shaped and diamond-shaped.
16. The method of claim 13 , wherein the fiber spinning apparatus is a spunbond apparatus.
17. A method for making an apertured nonwoven fabric, the method comprising the steps of:
a. providing a fiber laydown surface in the form of a first side of a continuous belt, the continuous belt comprising a reinforcing member and a pattern of three-dimensional raised elements extending outwardly from the reinforcing member on the first side of the continuous belt, the continuous belt further comprising a plurality of openings, each opening allowing fluid communication between the first side of the continuous belt and a second side of the continuous belt;
b. providing a fiber melt spinning apparatus above the first side of the continuous belt and a vacuum source below the second side of the continuous belt, wherein the continuous belt is moved in a machine direction between the fiber spinning apparatus and the vacuum source;
c. providing a compaction nip between a first pair of rolls, at least one of the rolls of the first pair of rolls being heated;
d. providing a bonding operation comprising a calendar nip;
e. melt spinning fibers from the melt spinning apparatus onto the fiber laydown surface as the continuous belt moves in the machine direction over the vacuum source to collect the melt spun fibers onto the fiber laydown surface, the collected melt spun fibers forming a nonwoven web having three-dimensional features, each three-dimensional feature defining a microzone comprising a first region and a second region, the first and second regions having a difference in values for an intensive property, wherein the intensive property is one or more of thickness, basis weight, and volumetric density; wherein in each microzone, the second region comprises a portion of the nonwoven web that is formed over the three-dimensional raised element of the continuous belt, and the first region comprises the remainder of the nonwoven web within the particular microzone;
f. moving the continuous belt in the machine direction through the compaction nip to create a compacted nonwoven web, the compaction nip being sized such that the second region of the microzone is compressed and heated to at least partially melt bond at least a portion of the fibers of the second region into frangible bond areas;
g. moving the compacted nonwoven web in the machine direction through the calendaring nip to create a compacted and calendared nonwoven web, the calendaring nip being sized to contact the compacted nonwoven web and impart infrangible thermal bonds to at least some of the fibers therein;
h. rolling the compacted and calendared nonwoven web into a rolled form;
i. providing an aperturing nip between a second pair of rolls; and
j. unrolling and moving the compacted and calendared nonwoven web through the aperturing nip, the aperturing nip forming an aperture at, or directly adjacent to, at least one of the frangible bond areas.
18. The method of claim 17 , wherein a distal surface of the raised elements have a two-dimensional shape having an aspect ratio of between 2 and 10.
19. The method of claim 17 , wherein the aperture has a perimeter, and a first portion of the perimeter comprises free fibers and a second portion of the perimeter comprises the partially melt bonded fibers of the frangible bond area.
20. The method of claim 17 , wherein the continuous belt comprises a second pattern of three-dimensional raised elements, the second pattern of three-dimensionally raised elements being visually distinct from the first pattern of three-dimensional raised elements.