Structural printing of absorbent webs

• US 20040099388A1
• Filed: 11/27/2002
• Published: 05/27/2004
• Est. Priority Date: 11/27/2002
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Tirimacco, Maurizio, Chen, Fung-Jou, Lindsay, Jeffrey D., Hunt, Thomas F., Urlaub, John J.
• Granted Patent: US 7,182,837 B2
• Time in Patent Office: Days
• US Class Current: 162/134
• CPC Class Codes: B05C 1/083 being passed between the coating roller and one or more backing rollers
• CPC Class Codes: B05C 1/0834 the coating roller co-operating with other rollers, e.g. dosing, transfer rollers
• CPC Class Codes: B05C 1/165 using a roller or other rotating member which contacts the work along a generating line
• CPC Class Codes: B41M 1/24 combined with embossing printing machines for carrying out printing operations combined with embossing B41F19/02
• CPC Class Codes: B41M 3/00 Printing processes to produce particular kinds of printed work, e.g. patterns printing apparatus or machines of special type or for particular purposes B41F17/00; special designs or pictures per se B44F; manufacturing printed circuits using printing techniques H05K3/12 ; manufacturing organic semiconductor devices using printing techniques H10K71/13
• CPC Class Codes: D21H 23/56 Rolls D21H23/38 takes precedence
• CPC Class Codes: Y10T 428/24455 Paper
• CPC Class Codes: Y10T 428/24479 including variation in thickness

Abstract

The present invention discloses a process and a method which may ‘lock in’ three dimensional texturing added to a paper web by virtue of an adhesive material which is printed onto the surface of the web. Specifically, it has been discovered that certain low pressure printing technologies may be used to deliver an adhesive material to the surface of a paper web such as a tissue, an air laid web, or a fibrous nonwoven web. The adhesive may be applied to the web either before, during or after the web is molded to increase the surface texture. The web may be molded under relatively low pressure so as to increase surface texture without significant deformation of the papermaking fibers. The cured adhesive material prevents the added texture from relaxing back in to a two dimensional state or may contribute additional texture by rising above the surface of the web. This process may not only increase the bulk of the web when dry and wet, but also increase the wet resiliency, the wet strength, and the tactile properties of the web.

Claims

1. A process for printing an adhesive material on a paper web comprising:

providing a paper web;

printing an adhesive material on one side of the web in a pattern;

molding the paper web into a three dimensional state defined by a pattern of raised web portions; and

curing the adhesive material, the adhesive material being located on the web such that the cured adhesive material prevents the three-dimensional state of the web from relaxing into a substantially two dimensional state.

2. The process of claim 1, wherein the printing process is selected from the group consisting of flexographic printing, inkjet printing, and digital printing processes.

3. The process of claim 1 wherein said printing process is a flexographic printing process.

4. The process of claim 3, wherein the flexographic printing process includes guiding the web through a printing nip comprising interdigitating rolls.

5. The process of claim 4, wherein the web is microstrained in the printing nip.

6. The process of claim 1, wherein the adhesive material has a Brookfield viscosity at 20 rpm of about 20 poise or greater.

7. The process of claim 1, wherein the adhesive material is a hot melt adhesive material and has a viscosity of about 1000 centipoise or greater when it is printed on the paper web.

8. The process of claim 1, wherein the printing process exerts a peak pressure on the web of less than about 100 psi.

9. The process of claim 1, wherein the printing process exerts a peak pressure on the web of between about 0.2 and about 30 psi.

10. The process of claim 1, further comprising printing the adhesive material onto the other side of the web by use of a low pressure printing process.

11. The process of claim 1, further comprising printing an additive on the web by use of a low pressure printing process.

12. The process of claim 1, wherein the pattern of adhesive material is heterogeneous across the surface of the web.

13. The process of claim 1, wherein the web is molded into a three dimensional state before the web is printed with the adhesive material.

14. The process of claim 1, wherein the web is molded into a three dimensional state after the web is printed with the adhesive material.

15. The process of claim 1, wherein the web is molded into a three-dimensional state at substantially the same time that the web is printed with the adhesive material.

16. The process of claim 1, wherein the web comprises two or more plies.

17. The process of claim 16, wherein the plies are joined together by mechanical means.

18. The process of claim 16, wherein the plies are joined together by adhesive means.

19. The process of claim 16, wherein the plies are dissimilar.

20. The process of claim 1, wherein the web comprises an uncreped tissue web.

21. The process of claim 1, wherein the web comprises a creped tissue web.

22. A process for producing a paper web comprising:

forming a paper web comprising papermaking fibers;

molding the paper web into a three dimensional state defined by a pattern of raised web portions;

printing an adhesive material in a pattern on one side of the web by use of a low pressure printing process such that the printing process does not substantially densify the web; and

curing the adhesive material, the adhesive material being located on the web such that the cured adhesive material prevents the three-dimensional state of the web from relaxing into a substantially two dimensional state.

23. The process of claim 22, wherein the paper web is molded into the three dimensional state before the adhesive material is printed on the web.

24. The process of claim 22, wherein the paper web is molded into the three dimensional state after the adhesive material is printed on the web.

25. The process of claim 22, wherein the paper web is printed with the adhesive material and molded into the three-dimensional state at substantially the same time.

26. The process of claim 22, further comprising microstraining the web.

27. The process of claim 22, wherein the web is molded by being subjected to a molding pressure which does not cause significant deformation of the papermaking fibers.

28. The process of claim 22, wherein the web is molded into a three-dimensional state by pressing the web against a molding substrate.

29. The process of claim 28, wherein the web is pressed against a molding substrate by a pneumatic force.

30. The process of claim 29, wherein the differential pressure across the web during said molding is between about 1 and about 200 kPa.

31. The process of claim 29, wherein the differential pressure across the web during said molding is between about 5 and about 150 kPa.

32. The process of claim 22, wherein the printing process exerts a peak pressure on the web of less than about 100 psi.

33. The process of claim 22, wherein the printing process exerts a peak pressure on the web of between about 0.2 and about 30 psi.

34. The process of claim 22, wherein the pattern of adhesive material comprises at least a portion of the areas of major curvature of the raised web portions.

35. The process of claim 22, wherein the pattern of adhesive material comprises the base of the raised web portions.

36. The process of claim 22, wherein the printing process is selected from the group consisting of flexographic printing, inkjet printing, and digital printing processes.

37. The process of claim 22, further comprising printing an additive on the web in a second pattern by use of a low pressure printing process wherein the printing process does not substantially densify the web.

38. The process of claim 22, further comprising printing the adhesive material on the second side of the paper web by use of a low pressure printing process wherein the printing process does not substantially densify the web.

39. The process of claim 22, wherein the adhesive material is printed onto one side of the web in a pattern which is heterogeneous across the surface of the web.

40. A process for producing a paper web comprising:

forming a paper web comprising papermaking fibers;

molding the paper web into a three dimensional state defined by a pattern of raised web portions, wherein the web is molded by being subjected to a molding pressure which does not cause significant deformation of the papermaking fibers;

printing an adhesive material on one side of the web in a first pattern by use of a flexographic printing process which exerts a peak pressure on the web of less than about 100 psi; and

curing the adhesive material, the adhesive material being located on the web such that the cured adhesive material prevents the three-dimensional state of the web from relaxing into a substantially two dimensional state.

41. The process of claim 40, wherein the paper web is molded into the three dimensional state before the adhesive material is printed on the web.

42. The process of claim 40, wherein the paper web is molded into the three dimensional state after the adhesive material is printed on the web.

43. The process of claim 40, wherein the web is molded in the flexographic printing nip.

44. The process of claim 40, wherein the flexographic printing nip comprises interdigitating rolls.

45. The process of claim 44 further comprising microstraining the web.

46. The process of claim 40, wherein the web is molded into a three-dimensional state by pressing the web against a molding substrate.

47. The process of claim 46, wherein the web is pressed against a molding substrate by a pneumatic force.

48. The process of claim 47, wherein the differential pressure across the web during said molding is between about 1 and about 200 kPa.

49. The process of claim 47, wherein the differential pressure across the web during said molding is between about 5 and about 150 kPa.

50. The process of claim 40, wherein the flexographic printing process exerts a peak pressure on the web of between about 0.2 and about 30 psi.

51. The process of claim 40, wherein the first pattern of adhesive material comprises the areas of the web at the base of the raised web portions.

52. The process of claim 40, wherein the flexographic printing apparatus does not include an impression cylinder.

53. The process of claim 40, further comprising printing an additive on the web.

54. The process of claim 40, further comprising printing the adhesive material on the second side of the web.

55. The process of claim 54, wherein the adhesive material is printed onto both sides of the web at the same time.

56. The process of claim 54, wherein the adhesive material is printed on the second side of the web in a second flexographic printing process.

57. The process of claim 40, wherein the pattern of adhesive material is heterogeneous across the surface of the web.

58. The process of claim 40, wherein the web comprises two or more plies.

59. The process of claim 58, wherein the plies are dissimilar.

60. The process of claim 40, wherein the web comprises a wetlaid tissue web.

61. The process of claim 40, wherein the web comprises an airlaid web.

62. A process for producing a three-dimensional paper web comprising:

forming a paper web comprising papermaking fibers and having a first Surface Depth on a first side of the paper web;

printing an adhesive material in a first pattern on the first side of the web by use of a flexographic printing process; and

curing the adhesive material to form a printed paper web having a second Surface Depth on the first side of the web, wherein the second Surface Depth is at least 0.04 mm greater than the first Surface Depth.

63. The process of claim 62, further comprising deforming the paper web into a three dimensional state prior to curing the adhesive material, the three-dimensional state defined by a pattern of raised web portions, wherein after curing the adhesive material is effective in retaining the three-dimensional state.

64. The process of claim 63, wherein the raised web portions comprise an elevation of at least about 0.1 mm.

65. The process of claim 63, wherein the three-dimensional state during the step of deforming the paper web has a characteristic peak-to-valley elevation difference, at least 20% of which is retained when the paper web is wetted.

66. The process of claim 62, wherein the adhesive material is present on less than about 80% of the surface area of the paper web.

67. The process of claim 62, wherein curing the adhesive material comprises heating the adhesive material.

68. The process of claim 62, wherein curing the adhesive material comprises applying electromagnetic radiation to the adhesive material.

69. The process of claim 62, wherein curing the adhesive material comprises allowing the adhesive material to cool.

70. A process for producing a three-dimensional paper web comprising:

forming a three-dimensional paper web comprising papermaking fibers and having a first surface with repeating three-dimensional structures having a Surface Depth of at least about 0.2 mm;

printing an adhesive material in a first pattern on the first surface of the web by use of a flexographic printing process; and

curing the adhesive material, wherein the cured adhesive material rises above the surface of the paper web by at least about 0.03 mm.

71. The process of claim 70, wherein the Surface Depth of the paper web increases upon printing the adhesive material on the web.

72. The process of claim 70, wherein the cured adhesive material rises above the surface of the paper web by at least about 0.07 mm.

73. The process of claim 70, wherein the cured adhesive material rises above the surface of the paper web by at least about 0.1 mm.

74. The process of claim 70, said adhesive material having a viscosity of at least about 20 poise.

75. A paper product comprising:

a paper web comprising papermaking fibers;

raised web portions projecting out of the plane of said paper web so as to provide a three dimensional texture to the web; and

an adhesive material applied to a first side of the paper web in a pattern, the pattern of adhesive material comprising areas of major curvature of the raised web portions as measured in the z-direction of the paper web, the cured adhesive material preventing the raised web portions from relaxing into the plane of the paper web.

76. The paper product of claim 75, wherein the paper web has a basis weight of between about 10 and about 200 grams per square meter.

77. The paper product of claim 75, wherein the paper web has a basis weight of between about 30 and about 90 grams per square meter.

78. The paper product of claim 75, wherein the paper web has a bulk of greater than about 3 cubic centimeters/gram.

79. The paper product of claim 75, wherein the paper web has a bulk of between about 3 and about 20 cubic centimeters/gram.

80. The paper product of claim 75, wherein the paper web has a Frazier air permeability of greater than about 10 cubic feet/minute.

81. The paper product of claim 75, wherein the paper web has a Surface Depth of about 0.2 mm or greater.

82. The paper product of claim 75 wherein the adhesive material covers between about 10% and 90% of the surface area of the paper web.

83. The paper product of claim 75 wherein the adhesive material is a hotmelt adhesive material having a Brookfield viscosity at 20 rpm of about 20 poise or greater.

84. The paper product of claim 75 wherein the adhesive material is a hotmelt adhesive material having a Brookfield viscosity at 20 rpm of about 50 poise or greater.

85. The paper product of claim 75 wherein the adhesive material is a hotmelt adhesive material having a Brookfield viscosity at 20 rpm of about 500 poise or greater.

86. The paper product of claim 75 wherein the adhesive material is a hotmelt adhesive material having a Brookfield viscosity at 20 rpm of about 1000 poise or greater.

87. The paper product of claim 75 wherein the adhesive material is applied to the web in a pattern which is heterogeneous across the surface of the web.

88. The paper product of claim 75 wherein the adhesive material is printed on the second side of the paper web in a second pattern.

89. The paper product of claim 75, wherein an additive is printed on a surface of the web.

90. The paper product of claim 75, wherein the paper web is a stratified paper web.

91. The paper product of claim 75, wherein the adhesive material is a latex.

92. The paper product of claim 75, wherein the pattern of adhesive material corresponds to the base areas of the raised web portions.