Fabric crepe and in fabric drying process for producing absorbent sheet
A method of making a cellulosic web includes: forming a nascent web from a papermaking furnish, the nascent web having a generally random distribution of papermaking fiber; b) transferring the web having a generally random distribution of papermaking fiber to a translating transfer surface moving at a first speed; drying the web to a consistency of from about 30 to about 60 percent including compactively dewatering the web prior to or concurrently with transfer to the transfer surface; fabric-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a creping fabric with a patterned creping surface, the fabric creping step occurring under pressure in a fabric creping nip defined between the transfer surface and the creping fabric wherein the fabric is traveling at a second speed slower than the speed of said transfer surface, the fabric pattern, nip parameters, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping fabric such that the web has a plurality of fiber-enriched regions arranged in a pattern corresponding to the patterned creping surface of the fabric, optionally drying the wet web while it is held in the creping fabric. Preferably, the formed web is characterized in that its void volume increases upon drawing.
1. A method of making a fabric-creped absorbent cellulosic sheet comprising:
a) forming a nascent web from a papermaking furnish, the nascent web having a generally random distribution of papermaking fiber;
b) transferring the web having a generally random distribution of papermaking fiber to a translating transfer surface moving at a transfer surface speed;
c) drying the web to a consistency of from about 30 to about 60 percent including compactively dewatering the web prior to or concurrently with transfer to the transfer surface;
d) fabric-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a creping fabric with a patterned creping surface, the fabric creping step occurring under pressure in a fabric creping nip defined between the transfer surface and the creping fabric wherein the fabric is traveling at a fabric speed slower than the speed of said transfer surface, the fabric pattern, nip parameters, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping fabric such that the web has a plurality of fiber-enriched regions of high local basis weight arranged in a pattern corresponding to the patterned creping surface of the fabric,
e) retaining the wet web in the creping fabric;
f) drying the wet web while it is held in the creping fabric to a consistency of at least about 90 percent; and
g) drawing the dried web, the step of drawing the dried web being effective to increase the void volume thereof by at least 5%.
2. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is dried with a plurality of can dryers while it is held in the creping fabric.
3. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is dried with an impingement-air dryer while it is held in the creping fabric.
4. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is drawn on-line.
5. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is drawn between a first roll operated at a machine direction velocity greater than the creping fabric velocity and a second roll operated at a machine direction velocity greater than the first roll.
6. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the dried web is calendered on-line.
7. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is drawn at least about 10% after fabric-creping.
8. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is drawn at least about 15% after fabric-creping.
9. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is drawn at least about 30% after fabric-creping.
10. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is drawn at least about 45% after fabric-creping.
11. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the web is drawn up to about 75% after fabric-creping.
12. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a fabric crepe of from about 10% to about 300% and a crepe recovery of from about 10% to about 100%.
13. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a crepe recovery of at least about 20%.
14. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a crepe recovery of at least about 30%.
15. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a crepe recovery of at least about 40%.
16. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a crepe recovery of at least about 50%.
17. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a crepe recovery of at least about 60%.
18. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a crepe recovery of at least about 80%.
19. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a crepe recovery of at least about 100%.
20. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a fabric crepe of from about 10 to about 100%.
21. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a fabric crepe of at least about 40%.
22. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a fabric crepe of at least about 60%.
23. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , operated at a fabric crepe of at least about 80%.
24. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web until it achieves a void volume of at least about 6 gm/gm.
25. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web until it achieves a void volume of at least about 7 gm/gm.
26. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web until it achieves a void volume of at least about 8 gm/gm.
27. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web until it achieves a void volume of at least about 9 gm/gm.
28. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web until it achieves a void volume of at least about 10 gm/gm.
29. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the dried web and increasing its void volume by at least about 10%.
30. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the dried web and increasing its void volume by at least about 25%.
31. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the dried web and increasing its void volume by at least about 50%.
32. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web and preferentially attenuating the fiber-enriched regions of the web.
33. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the orientation of fibers in the fiber-enriched regions is biased in the CD.
34. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , wherein the fiber-enriched regions have a plurality of microfolds with fold lines extending transverse to the machine direction, and wherein drawing the web in the machine direction expands the microfolds.
35. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web and increasing its bulk.
36. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web and reducing the sidedness of the web.
37. The method of making a fabric-creped absorbent cellulosic sheet according to claim 1 , including drawing the web and reducing the TMI Friction value of the fabric side of the web.
38. A method of making a fabric-creped absorbent cellulosic sheet comprising:
a) compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber;
b) applying the dewatered web having the apparently random fiber distribution to a translating transfer surface moving at a transfer surface speed;
c) fabric-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent, the creping step occurring under pressure in a fabric creping nip defined between the transfer surface and the creping fabric wherein the fabric is traveling at a fabric speed slower than the speed of said transfer surface, the fabric pattern, nip parameters, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping fabric to form a web with a drawable reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber-enriched regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions;
d) drying the web; and
e) drawing the web,
wherein the web is can-dried in a two-tier can drying section such that both the fabric side of the web and the opposite side of the web contact the surface of at least one dryer can and wherein the void volume is increased by at least by at least 5%.