Method of making a fabric-creped absorbent cellulosic sheet

• US 8,328,985 B2
• Filed: 02/22/2012
• Issued: 12/11/2012
• Est. Priority Date: 10/07/2002
• Status: Expired due to Term

• Current Assignee: GPCP IP Holdings LLC
• Original Assignee: Georgia-Pacific Consumer Products LP (KOCH Industries Incorporated)
• Inventors: Edwards, Steven L., Super, Guy H., McCullough, Stephen J., Reeb, Ronald R., Chou, Hung Liang, Yeh, Kang Chang, Dwiggins, John H., Harper, Frank D.
• Primary Examiner(s): Fortuna, Jose A
• Application Number:
  US13/402,132
• Publication Number:
  US 20120145344A1
• Time in Patent Office: 293 Days
• Field of Search: 162/109, 162111-113, 162115-117, 162123-133, 162/193, 162/197, 162204-207, 156/183, 264282-283, 226/7, 226/91, 226/97.3, 341/14, 341/17, 341/22, 343/59, 344/44
• US Class Current: 162/111
• CPC Class Codes: D21F 11/006 Making patterned paper
• CPC Class Codes: D21F 11/14 Making cellulose wadding, filter or blotting paper
• CPC Class Codes: D21F 11/145 including a through-drying process
• CPC Class Codes: D21H 21/20 Wet strength agents
• CPC Class Codes: D21H 25/005 Mechanical treatment D21H25/08, D21H25/18 take precedence
• CPC Class Codes: D21H 27/40 at least one of the sheets being non-planar, e.g. crêped crêping or corrugating paper B31F
• CPC Class Codes: Y10T 428/24455 Paper
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24612 Composite web or sheet

Abstract

A method of making a fabric-creped absorbent cellulosic sheet includes compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber, applying the nascent web having the apparently random fiber distribution to a translating transfer surface that is moving at a transfer surface speed, and fabric-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping fabric, the fabric-creping step occurring under pressure in a fabric creping nip defined between the transfer surface and the creping fabric, the web being creped from the transfer surface and wherein the creping fabric is adapted to contact the transfer surface and applies pressure to the web against the transfer surface such that the fibers of the web are redistributed on the creping fabric to form a web with a drawable reticulum.

Claims

1. A method of making a fabric-creped absorbent cellulosic sheet, the method comprising:

(a) compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber;

(b) applying the nascent web having the apparently random fiber distribution to a translating transfer surface that is 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 utilizing a patterned creping fabric, 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 that is slower than the speed of the transfer surface, the web being creped from the transfer surface and wherein the creping fabric is adapted to contact the transfer surface and applies pressure to the web against the transfer surface such that the fibers of the web are 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 a high local basis weight having a plurality of microfolds with fold lines extending transverse to the machine direction, interconnected by way of (ii) a plurality of lower local basis weight linking regions,

wherein the drawable reticulum of the web is characterized in that it comprises a cohesive fiber matrix capable of increases in void volume when dried and subsequently drawn;

(d) drying the web to form a dried web; and

(e) drawing the dried web in the machine direction to expand the plurality of microfolds.

2. The method according to claim 1, wherein the drawing step increases the bulk of the web.

3. The method according to claim 1, wherein the drawing step decreases the sided-ness of the web.

4. The method according to claim 1, wherein the drawing step attenuates the fiber-enriched regions of the web.

5. The method according to claim 1, further comprising controlling the fabric creping and processing parameters such that the orientation of fibers in the fiber-enriched regions is biased in the cross-machine direction (CD).

6. The method according to claim 1, wherein the fabric-creping step is operated at a fabric crepe of from about 10 to about 300%.

7. The method according to claim 1, wherein the fabric-creping step is operated at a fabric crepe of at least about 40%.

8. The method according to claim 1, wherein the fabric-creping step is operated at a fabric crepe of at least about 60%.

9. The method according to claim 1, wherein the fabric-creping step is operated at a fabric crepe of at least about 80%.

10. The method of according to claim 1, wherein the fabric-creping step is operated at a fabric crepe of at least 100%.

11. The method according to claim 10, wherein the fabric-creping step is operated at a fabric crepe of at least about 125%.

12. The method according to claim 1, wherein the creping fabric is adapted to contact a creping roll over a nip width of at least about ⅛

″

.

13. The method according to claim 1, wherein the creping fabric is adapted to contact a creping roll over a nip width of at least ½

″

.

14. The method according to claim 1, wherein the creping fabric is adapted to contact a creping roll over a nip width of from about ⅛

″

to about 2″

.

15. The method according to claim 1, wherein the creping fabric is adapted to contact a creping roll over a nip width of from ½

″

to 2″

.

16. The method according to claim 1, wherein the fabric-creping step takes place under a pressure of at least 20 pounds per linear inch.

17. The method according to claim 1, wherein the fabric-creping step takes place under a pressure of from 20 to about 200 pounds per linear inch.

18. The method according to claim 1, wherein the fabric-creping step takes place under a pressure of from 40 to about 70 pounds per linear inch.

19. A method of making a fabric-creped absorbent cellulosic sheet, the method comprising:

(a) compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber;

(b) applying the nascent web having the apparently random fiber distribution to a translating transfer surface that is 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 utilizing a patterned creping fabric, 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 that is slower than the speed of the transfer surface, the web being creped from the transfer surface and wherein the creping fabric is adapted to contact the transfer surface and applies pressure to the web against the transfer surface such that the fibers of the web are 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 a high local basis weight having a plurality of microfolds with fold lines extending transverse to the machine direction, interconnected by way of (ii) a plurality of lower local basis weight linking regions;

(d) applying the web to a drying cylinder;

(e) drying the web on the drying cylinder to form a dried web;

(f) removing the dried web from the drying cylinder;

wherein steps (d), (e) and (f) are performed so as to substantially preserve the drawable fiber reticulum, and

(g) drawing the dried web in the machine direction to expand the plurality of microfolds.

20. The method of according to claim 19, wherein the drying cylinder is a Yankee dryer.

21. The method according to claim 20, wherein the dried web is removed from the Yankee dryer without substantial creping.

22. The method according to claim 20, wherein, subsequent to startup, the dried web is removed from the Yankee dryer without a creping blade.

23. The method according to claim 19, wherein the fabric-creping step is operated at a fabric crepe of from about 10% to about 100% and the drawing step is operated at a crepe recovery of from about 10% to about 100%.

24. The method according to claim 19, wherein the drawing step is operated at a crepe recovery of at least about 20%.

25. The method according to claim 19, wherein the drawing step is operated at a crepe recovery of at least about 30%.

26. The method according to claim 19, wherein the drawing step is operated at a crepe recovery of at least about 40%.

27. The method according to claim 19, wherein the drawing step is operated at a crepe recovery of at least about 50%.

28. The method according to claim 19, wherein the drawing step is operated at a crepe recovery of at least about 60%.

29. The method according to claim 19, wherein the drawing step is operated at a crepe recovery of at least about 80%.

30. The method according to claim 19, wherein the drawing step is operated at a crepe recovery of at least about 95%.

31. The method according to claim 19, wherein the web comprises secondary fiber.

32. The method according to claim 19, wherein the web is drawn on-line.

33. The method according to claim 19, wherein the web is drawn between a first roll operated at a machine direction velocity that is greater than the creping fabric velocity and a second roll operated at a machine direction velocity that is greater than that of the first roll.

34. The method according to claim 19, wherein the dried web is calendered on-line.

35. The method according to claim 19, wherein the web is dried to a consistency of at least about 90% prior to drawing.

36. The method according to claim 19, wherein the web is dried to a consistency of at least about 92% prior to drawing.

37. The method according to claim 19, further comprising controlling the fabric creping and processing parameters such that the ratio of percent decrease in caliper/percent decrease in basis weight of the web is less than about 0.85 upon drawing the web.

38. The method according to claim 19, further comprising controlling the fabric creping and processing parameters such that the ratio of percent decrease in caliper/percent decrease in basis weight of the web is less than about 0.7 upon drawing the web.

39. The method according to claim 19, further comprising controlling the fabric creping and processing parameters such that the ratio of percent decrease in caliper/percent decrease in basis weight of the web is less than about 0.6 upon drawing the web.

40. The method according to claim 19, wherein the creping fabric is adapted to contact a creping roll over a nip width of at least about ⅛

″

.

41. The method according to claim 19, wherein the creping fabric is adapted to contact a creping roll over a nip width of at least ½

″

.

42. The method according to claim 19, wherein the creping fabric is adapted to contact a creping roll over a nip width of from about ⅛

″

to about 2″

.

43. The method according to claim 19, wherein the creping fabric is adapted to contact a creping roll over a nip width of from ½

″

to 2″

.

44. The method according to claim 19, wherein the creping step takes place under a pressure of at least twenty pounds per linear inch.

45. The method according to claim 19, wherein the creping step takes place under a pressure of from about 20 to about 200 pounds per linear inch.

46. The method according to claim 19, wherein the creping step takes place under a pressure of from about 40 to about 70 pounds per linear inch.

47. A method of making a fabric-creped absorbent cellulosic sheet, the method comprising:

(a) compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber;

(b) applying the nascent web having the apparently random fiber distribution to a translating transfer surface that is moving at a transfer surface speed; and

(c) fabric-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a creping fabric, 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 that is slower than the speed of the transfer surface, the web being creped from the transfer surface, and wherein the creping fabric is adapted to contact the transfer surface and applies pressure to the web against the transfer surface such that the fibers of the web are 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 a high local basis weight having a plurality of microfolds with fold lines extending transverse to the machine direction, interconnected by way of (ii) a plurality of lower local basis weight linking regions;

(d) applying a vacuum to the web to increase the cross-machine direction (CD) stretch of the web;

(e) drying the web to form a dried web; and

(f) drawing the dried web in the machine direction to expand the plurality of microfolds.

48. The method according to claim 47, further comprising applying a vacuum to the web while the web is held in the creping fabric, and selecting the creping fabric to increase the cross-machine direction (CD) stretch when the vacuum is applied to the web.

49. The method according to claim 47, further comprising applying at least 5 inches Hg of vacuum.

50. The method according to claim 47, further comprising applying at least 10 inches Hg of vacuum.

51. The method according to claim 47, further comprising applying at least 15 inches Hg of vacuum.

52. The method according to claim 47, further comprising applying at least 20 inches Hg of vacuum.

53. The method according to claim 47, further comprising applying at least 25 inches Hg of vacuum.

54. The method according to claim 47, wherein applying the vacuum to the web increases the cross-machine direction (CD) stretch of the web by at least about 7.5 percent with respect to a like web produced by the same means, but without having a vacuum applied thereto after fabric creping.

55. The method according to claim 47, wherein applying the vacuum to the web increases the cross-machine direction (CD) stretch of the web by at least about 10 percent with respect to a like web produced by the same means, but without having a vacuum applied thereto after fabric creping.

56. The method according to claim 47, wherein applying the vacuum to the web increases the cross-machine direction (CD) stretch of the web by at least about 20 percent with respect to a like web produced by the same means, but without having a vacuum applied thereto after fabric creping.

57. The method according to claim 47, wherein applying the vacuum to the web increases the cross-machine direction (CD) stretch of the web by at least about 35 percent with respect to a like web produced by the same means, but without having a vacuum applied thereto after fabric creping.

58. The method according to claim 47, wherein applying the vacuum to the web increases the cross-machine direction (CD) stretch of the web by at least about 50 percent with respect to a like web produced by the same means, but without having a vacuum applied thereto after fabric creping.

59. The method according to claim 47, wherein the creping fabric is adapted to contact a creping roll over a nip width of at least about ⅛

″

.

60. The method according to claim 47, wherein the creping fabric is adapted to contact a creping roll over a nip width of at least ½

″

.

61. The method according to claim 47, wherein the creping fabric is adapted to contact a creping roll over a nip width of from about ⅛

″

to about 2″

.

62. The method according to claim 47, wherein the creping fabric is adapted to contact a creping roll over a nip width of is from ½

″

to 2″

.

63. The method according to claim 47, wherein the creping step takes place under a pressure of at least 20 pounds per linear inch.

64. The method according to claim 47, wherein the creping step takes place under a pressure of from 20 to about 200 pounds per linear inch.

65. The method according to claim 47, wherein the creping step takes place under a pressure of from 40 to about 70 pounds per linear inch.