SOFT ABSORBENT SHEETS, STRUCTURING FABRICS FOR MAKING SOFT ABSORBENT SHEETS, AND METHODS OF MAKING SOFT ABSORBENT SHEETS

• US 20170089013A1
• Filed: 12/07/2016
• Published: 03/30/2017
• Est. Priority Date: 06/08/2015
• Status: Active Grant

• Current Assignee: GPCP IP Holdings LLC
• Original Assignee: Georgia-Pacific Consumer Products LP (KOCH Industries Incorporated)
• Inventors: Sze, Daniel Hue Ming, Fan, Xiaolin, Chou, Hung-Liang, Oriaran, Taiye Philips, Anand, Farminder Singh, Baumgartner, Dean Joseph, Miller, Joseph Henry
• Granted Patent: US 10,138,601 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 7/08 Felts
• CPC Class Codes: D21F 7/12 Drying
• CPC Class Codes: D21H 11/00 Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
• CPC Class Codes: D21H 27/002 Tissue paper; Absorbent paper D21H21/22, D21H27/02, D21H27/20 take precedence; toilet paper A47K10/00; absorbent pads for physiological fluids A61L15/16; making on paper-making machines D21F11/00
• CPC Class Codes: D21H 27/005 relating to physical or mechanical properties, e.g. tensile strength, stretch, softness

Abstract

Soft absorbent sheets, structuring fabrics for producing soft absorbent sheets, and methods of making soft absorbent sheets. The soft absorbent sheets have a plurality of projected regions and connecting regions that connect the projected regions. The projected regions include folds that are curved relative to a machine direction of the absorbent sheet, with ends of the curved folds being on opposite sides of the projected regions, and with apexes of the curved folds being positioned downstream in the machine direction of the absorbent sheet. The absorbent sheets can be formed by structuring fabrics that have angled lines of warp yarn knuckles.

Claims

1. An absorbent cellulosic sheet comprising:

a plurality of projected regions projecting from the absorbent sheet, wherein the projected regions are formed in folds that are curved relative to a machine direction of the absorbent sheet, with ends of the curved folds being on opposite sides of the projected regions and such that one of the ends of each of the curved folds is positioned downstream from the other end of the curved folds in the machine direction of the absorbent sheet, and with apexes of the curved folds being positioned downstream in the machine direction of the absorbent sheet; and

connecting regions connecting the projected regions of the absorbent sheet.

2. An absorbent cellulosic sheet according to claim 1, wherein each of the projected regions includes a plurality of the curved folds.

3. An absorbent cellulosic sheet according to claim 2, further including indented bars formed between the curved folds in each projected region.

4. An absorbent cellulosic sheet according to claim 1, wherein an average radius of curvature of the curved folds is about 1.2 mm.

5. An absorbent cellulosic sheet according to claim 1, further including a plurality of folds at positions adjacent to ends of the projected regions that are upstream in the machine direction of the absorbent sheet.

6. An absorbent cellulosic sheet comprising:

a plurality of projected regions projecting from the absorbent sheet, wherein the projected regions are formed in folds that are curved relative to a machine direction of the absorbent sheet, with ends of the curved folds being on opposite sides of the projected regions, the curved folds having a radius of curvature of about 0.5 mm to about 2.0 mm; and

connecting regions connecting the projected regions of the absorbent sheet.

7. An absorbent cellulosic sheet according to claim 6, wherein an average radius of curvature of the curved folds is about 1.2 mm.

8. An absorbent cellulosic sheet according to claim 6, wherein each of the projected regions includes a plurality of the curved folds.

9. An absorbent cellulosic sheet according to claim 8, further including indented bars formed between the curved folds in each projected region.

10. An absorbent cellulosic sheet according to claim 6, further including a plurality of folds at positions adjacent to ends of the projected regions that are upstream in the machine direction of the absorbent sheet.

11. A papermaking web comprising:

a plurality of projected regions projecting from the papermaking web, wherein the projected regions are formed in folds that are curved relative to a machine direction of the papermaking web, with ends of the curved folds being on opposite sides of the projected regions and such that one of the ends of each of the curved folds is positioned downstream from the other end of the curved folds in the machine direction of the papermaking web, and with apexes of the curved folds being positioned downstream in the machine direction of the papermaking web; and

connecting regions connecting the projected regions of the papermaking web.

12. A papermaking web according to claim 11, wherein each of the projected regions includes a plurality of the curved folds.

13. A papermaking web according to claim 12, further including indented bars formed between the curved folds in each projected region.

14. A papermaking web according to claim 12, wherein a radius of curvature of the folds is about 0.5 mm to about 2.0 mm.

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

compactively dewatering a papermaking furnish to form a web;

creping the web under pressure in a creping nip between a transfer surface and a structuring fabric, the structuring fabric including knuckles formed on warp yarns of the structuring fabric, with the knuckles being positioned along lines that are angled relative to the machine direction of the fabric, wherein the angle of lines relative to the machine direction is between about 10° and

about 30°

; and

drying the web to form the absorbent cellulosic sheet.

16. A method according to claim 15, wherein a creping ratio is defined by the speed of the transfer surface relative to the speed of the structuring fabric, and the creping ratio is about 3% to about 25%.

17. A method according to claim 15, wherein the angle of lines relative to the machine direction is between about 15°

.

18. A method according to claim 15, wherein the warp yarns of the structuring fabric are sloped downwards at positions adjacent to downstream ends of the knuckles, and the web is folded at positions adjacent to the downward slopes of the warp yarn.

19. A method according to claim 15, wherein the length of the knuckles in the MD is about 2.4 mm to about 5.7 mm.

20. A method according to claim 15, wherein a planar volumetric density index of the structuring fabric multiplied by the length to width ratio of the knuckles formed on the warp yarns is about 41 to about 123.

21. An absorbent cellulosic sheet made by the method of claim 15, the absorbent cellulosic sheet comprising:

a plurality of projected regions projecting from the absorbent sheet, wherein the projected regions are formed in folds that are curved relative to a machine direction of the absorbent sheet, with ends of the curved folds being on opposite sides of the projected regions, and with apexes of the curved folds being positioned downstream in the machine direction of the absorbent sheet.

22. An absorbent cellulosic sheet comprising:

a plurality of projected regions projecting from the absorbent sheet, wherein the projected regions are formed in folds that are curved relative to a machine direction of the absorbent sheet, with ends of the curved folds being on opposite sides of the projected regions, wherein the absorbent sheet has a normalized fold curvature ratio that is less than about 4; and

connecting regions connecting the projected regions of the absorbent sheet.

23. An absorbent sheet according to claim 22, wherein the normalized fold curvature ratio for the fabric is about 0.5 to about 4.

24. An absorbent sheet according to claim 23, wherein the normalized fold curvature ratio for the fabric is about 2.

25. An absorbent sheet according to claim 22, wherein the average radius of curvature for the curved folds is about 0.5 mm to about 2.0 mm.

26. An absorbent cellulosic sheet according to claim 22, wherein each of the projected regions includes a plurality of the curved folds.

27. An absorbent cellulosic sheet according to claim 26, further including indented bars formed between the curved folds in each projected region.