Fabric crepe process for making absorbent sheet

• US 7,399,378 B2
• Filed: 10/06/2003
• Issued: 07/15/2008
• Est. Priority Date: 10/07/2002
• Status: Active Grant

• Current Assignee: GPCP IP Holdings LLC
• Original Assignee: Georgia-Pacific Consumer Products LP (KOCH Industries Incorporated)
• Inventors: Super, Guy H., McCullough, Stephen J., Edwards, Steven L., Eggen, Richard W., Krueger, Jeffrey E., Lomax, David W., Duggan, David P., Baumgartner, Dean J., Jones, Colin A.
• Primary Examiner(s): FORTUNA, JOSE A
• Application Number:
  US10/679,862
• Publication Number:
  US 20040238135A1
• Time in Patent Office: 1,744 Days
• Field of Search: 162/109, 162111-113, 162115-117, 162123-133, 156/183, 264282-283
• 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 428/24446 Wrinkled, creased, crinkled or creped
• CPC Class Codes: Y10T 428/24455 Paper
• CPC Class Codes: Y10T 428/24479 including variation in thickness

Abstract

A process for making absorbent cellulosic paper products such as sheet for towel, tissue and the like, includes compactively dewatering a nascent web followed by wet belt creping the web at an intermediate consistency of anywhere from about 30 to about 60 percent under conditions operative to redistribute the fiber on the belt, which is preferably a fabric. In preferred embodiments, the web is thereafter adhesively applied to a Yankee dryer using a creping adhesive operative to enable high speed transfer of the web of intermediate consistency such as a poly(vinyl alcohol)/polyamide adhesive. An absorbent sheet so prepared from a papermaking furnish exhibits an absorbency of at least about 5 g/g, a CD stretch of at least about 4 percent, and an MD/CD tensile ratio of less than about 1.1, and also exhibits a maximum CD modulus at a CD strain of less than 1 percent and sustains a CD modulus of at least 50 percent of its maximum CD modulus to a CD strain of at least about 4 percent. Products of the invention may also exhibit an MD modulus at break 1.5 to 2 times their initial MD modulus.

Claims

1. A method of making a belt-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) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface, the belt 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 belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions; and

d) drying the web.

wherein the method is further characterized in that;

(i) the web has an absorbency of at least 4.5g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g and a CD stretch of at least about 5% up to about 20%;

or (ii) the velocity delta at the creping nip is at least 100 feet per minute up to about 2000 fpm;

or both (i) and (ii).

2. The method according to claim 1, operated at a Fabric Crepe of at least about 20 percent up to 80 percent.

3. The method according to claim 1, operated at a Fabric Crepe of at least about 40 percent.

4. The method according to claim 1, operated at a Fabric Crepe of at least about 60 percent.

5. The method according to claim 1, wherein the web has a CD stretch of from about 5 percent to about 10 percent.

6. The method according to claim 1, wherein the web has a CD stretch of from about 6 percent to about 8 percent.

7. The method according to claim 1, wherein the web has an MD stretch of at least about 15 percent up to 80 percent.

8. The method according to claim 7, wherein the web has an MD stretch of at least about 30 percent.

9. The method according to claim 7, wherein the web has an MD stretch of at least about 55 percent.

10. The method according to claim 7, wherein the web has an MD stretch of at least about 75 percent.

11. The method according to claim 1, wherein the web has an MD/CD tensile ratio of less than about 1.1 and at least about 0.5.

12. The method according to claim 1, wherein the web exhibits an MD/CD tensile ratio of from about 0.5 to about 0.9.

13. The method according to claim 1, wherein the web exhibits an MD/CD tensile ratio of from about 0.6 to about 0.8.

14. The method according to claim 1, wherein the web is belt-creped at a consistency of from about 35 percent to about 55 percent.

15. The method according to claim 1, wherein the web is belt-creped at a consistency of from about 40 percent to about 50 percent.

16. The method according to claim 1, wherein the creping nip pressure is from about 40 PLI to about 80 PLI.

17. The method according to claim 1, wherein the creping nip pressure is from about 50 PLI to about 70 PLI.

18. The method according to claim 1, wherein the creping belt is supported in the creping nip with a backing roll having a surface hardness of from about 20 to about 120 on the Pusey and Jones hardness scale.

19. The method according to claim 1, wherein the creping belt is supported in the creping nip with a backing roll having a surface hardness of from about 25 to about 90 on the Pusey and Jones hardness scale.

20. The method according to claim 1, wherein the creping nip extends over a distance of at least about 1/16″

up to about 2″

.

21. The method according to claim 1, wherein the creping nip extends over a distance of at least about ⅛

″

up to about 2″

.

22. The method according to claim 1, wherein the creping nip extends over a distance of from about ½

″

to about 2″

.

23. A method of making a belt-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) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt 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 belt,

d) drying the web;

wherein the web has an absorbency of at least 5 g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g.

24. The method according to claim 23, wherein the web has an absorbency of at least about 6 g/g.

25. The method according to claim 23, wherein the web has an absorbency of at least about 7 g/g.

26. The method according to claim 23, wherein the web has an absorbency of at least about 8 g/g.

27. A method of making a fabric-creped absorbent cellulosic sheet comprising:

a) compactively dewatering a papermaking furnish to form a nascent web;

b) applying the dewatered web to the surface of a rotating transfer cylinder rotating at a transfer surface speed such that the surface velocity of the cylinder is at least about 1000 fpm;

c) fabric-creping the web from the transfer cylinder at a consistency of from about 30 to about 60 percent under pressure of 20 pounds per linear inch or more in a high impact fabric creping nip defined between the transfer cylinder and a creping fabric traveling at a fabric speed slower than said surface velocity of the transfer cylinder by at least 100 feet per minute and wherein the fabric speed is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, wherein the web is creped from the cylinder and rearranged on the creping fabric; and

d) drying the web, wherein the web has an absorbency of at least about 5 g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g and a CD stretch of at least about 4 percent up to about 20 percent.

28. The method according to claim 27, wherein the surface velocity of the transfer cylinder is at least about 2000 fpm up to about 6000 fpm.

29. The method according to claim 27, wherein the surface velocity of the transfer cylinder is at least about 4000 fpm up to about 6000 fpm.

30. The method according to claim 27, wherein the web has an absorbency of from about 5 g/g to about 12 g/g.

31. The method according to claim 27, wherein the absorbency of the web (g/g) is at least about 0.7 times the specific volume of the web (cc/g) up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g.

32. The method according to claim 27, wherein the absorbency of the web (g/g) is from about 0.75 to about 0.9 times the specific volume of the web cc/g).

33. The method according to claim 27, wherein the aqueous furnish includes a wet strength resin.

34. The method according to claim 27, wherein the wet strength resin comprises a polyamide-epicholorohydrin resin.

35. The method according to claim 27, wherein the web is dewatered by wet pressing it with a papermaking felt while applying the web to the transfer cylinder.

36. The method according to claim 35, wherein the step of wet-pressing the web with a papermaking felt while applying it to the transfer roll is carried out in a shoe press.

37. The method according to claim 27, wherein the transfer roll is a shoe press roll and the nascent web is further dewatered by wet-pressing the web while applying it to the transfer roll.

38. The method according to claim 27, further comprising the steps of forming a nascent web on a forming fabric, transferring the nascent web to a papermaking felt and dewatering the web by wet pressing it between the papermaking felt and the transfer cylinder.

39. The method according to claim 27, wherein the fabric creping nip extends over a distance corresponding to at least twice the distance between wefts of the creping fabric up to a distance corresponding to 40 times the distance between the wefts of the creping fabric.

40. The method according to claim 27, wherein the fabric creping nip extends over a distance corresponding to at least 4 times the distance between wefts of the creping fabric up to a distance corresponding to 40 times the distance between the wefts of of the creping fabric.

41. The method according to claim 27, wherein the fabric creping nip extends over a distance corresponding to at least 10 times the distance between wefts of the creping fabric up to a distance corresponding to 40 times the distance between the wefts of of the creping fabric.

42. The method according to claim 27, wherein the fabric creping nip extends over a distance corresponding to at least 20 times the distance between wefts creping fabric up to a distance corresponding to 40 times the distance between the wefts of of the creping fabric.

43. A method of making single-ply tissue 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) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt pattern, nip pressure, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions and (iii) wherein the Fabric Crepe is greater than about 25% up to 80%;

d) drying the web to form a basesheet having an MD stretch greater than about 25% up to 80% and a characteristic basis weight; and

e) converting the basesheet into a single-ply tissue product wherein the single-ply tissue product has a basis weight lower than the basesheet prior to conversion and an MD stretch lower than the MD stretch of the basesheet prior to conversion.

44. The method according to claim 43, wherein the product is calendered.

45. The method according to claim 43, wherein the product has a 12-ply caliper (microns) to basis weight (gms/m²) ratio of greater than about 95 and up to about 120.

46. A method of making multi-ply tissue 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) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt 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 belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions and (iii) wherein the Fabric Crepe is greater than about 25% up to 80%;

d) drying the web to form a basesheet having an MD stretch greater than about 25% up to 80% and a characteristic basis weight; and

e) converting the basesheet into a multi-ply tissue product with n plies made from the base sheet, n being 2 or 3, wherein the multiply product has an MD stretch lower than the MD stretch of the basesheet.

47. The method according to claim 46, wherein n=2 such that the tissue product is a two-ply tissue product.

48. The method according to claim 46, wherein the basesheet has an MD stretch of at least about 30%.

49. The method according to claim 46, wherein the basesheet has an MD stretch of at least about 40%.

50. The method according to claim 46, wherein the product is calendered.

51. The method according to claim 46, wherein the product has a 12-ply caliper (microns) to basis weight (gms/m²) ratio of greater than about 95.

52. The method according to claim 46, wherein the product has a 12-ply caliper (microns) to basis weight (gms/m²) ratio of greater than about 95 and up to about 120.

53. A method of making a belt-creped absorbent cellulosic sheet comprising:

a) applying a papermaking furnish to a papermaking felt in contact with a forming roll provided with vacuum;

b) at least partially dewatering the papermaking furnish by application of vacuum from the forming roll on the papermaking felt to form a nascent web having a generally random distribution of papermaking fiber;

c) compactively dewatering the nascent web having a generally random distribution of papermaking fiber;

d) applying the dewatered web having a generally random fiber distribution to a translating transfer surface moving at a transfer surface speed;

e) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt 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 belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased along the direction between pileated regions; and

f) drying the web;

wherein the web has an absorbency of at least about 4.5 g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g and a CD stretch of at least about 5% up to about 20%.

54. The method of claim 53, carried out on a 3-fabric papermachine.

55. The method according to claim 54, wherein the step of drying the web comprises applying the web to a Yankee dryer.

56. The method according to claim 55, wherein the step of applying the web to the Yankee dryer comprises utilizing a poly(vinyl alcohol) containing adhesive.

57. The method according to claim 53, wherein the papermaking felt is inclined upwardly.

58. The method according to claim 53, further comprising a pressure roll configured to urge the papermaking felt against the forming roll.

59. The method according to claim 58, wherein the pressure roll has a surface hardness of from about 20 to about 120 on the Pusey and Jones hardness scale.

60. The method according to claim 58, wherein the pressure roll has a surface hardness of from about 25 to about 90 on the Pusey and Jones hardness scale.

61. A method of making a belt-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) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface, the belt 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 belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions; and

d) drying the web;

wherein the web has a CD stretch of from about 5 percent to about 20 percent, and an absorbency of at least 5 g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g.

62. The method according to claim 61, wherein the web has a CD stretch of from about 5 percent to about 10 percent.

63. The method according to claim 61, wherein the web has a CD stretch of from about 6 percent to about 8 percent.

64. The method according to claim 61, wherein the web has an absorbency of at least about 6 g/g.

65. The method according to claim 61, wherein the web has an absorbency of at least about 7 g/g.

66. The method according to claim 61, wherein the web has an absorbency of at least about 8 g/g.

67. A method of making a belt-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) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface, the belt 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 belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions; and

d) drying the web;

wherein the web has a CD stretch of from about 5 percent to about 20 percent, an absorbency of at least 5 g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g, and an MD/CD tensile ratio of less than about 1.1 and at least about 0.5.

68. The method according to claim 67, wherein the web exhibits an MD/CD tensile ratio of from about 0.5 to about 0.9.

69. The method according to claim 67, wherein the web exhibits an MD/CD tensile ratio of from about 0.6 to about 0.8.

70. The method according to claim 67, wherein the web has a CD stretch of from about 6 percent to about 8 percent.

71. A method of making a belt-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) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface, the belt 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 belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions; and

d) drying the web;

wherein the method is further characterized in that;

(i) the web has an absorbency of from about 5 g/g to about 12 g/g;

or (ii) the velocity delta at the creping nip is at least 100 feet per minute up to about 2000 fpm;

or both (i) and (ii).

72. A method of making a belt-creped absorbent cellulosic sheet comprising:

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

f) applying the dewatered web having the apparently random fiber distribution to a translating transfer surface moving at a transfer surface speed;

g) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt 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 belt,

d) drying the web;

wherein the web has an absorbency of from about 5 g/g to about 12 g/g.