Methods of making fabric-creped absorbent cellulosic sheets

Patent metadata

Field	Value
Publication number	US-11788232-B2
Application number	US-202117231192-A
Country	US
Kind code	B2
Filing date	Apr 15, 2021
Priority date	Jun 8, 2015
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

A method of making a fabric-creped absorbent cellulosic sheet. The method includes compactively dewatering a papermaking furnish to form a web having a consistency of about thirty percent to about sixty percent, creping the web under pressure in a creping nip between a transfer surface and a structuring fabric, and drying the web to form the absorbent cellulosic sheet. The absorbent sheet has SAT capacities of at least about 9.5 g/g and at least about 500 g/m 2 . 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 less than about 25%.

First claim

We claim:

1. A method of making a fabric-creped absorbent cellulosic sheet, the method comprising:
compactively dewatering a papermaking furnish to form a web having a consistency of about thirty percent to about sixty percent;
creping the web under pressure in a creping nip between a transfer surface and a structuring fabric, the transfer surface moving at a transfer surface speed and the structuring fabric moving at a structuring fabric speed, wherein the structuring fabric has (a) machine direction (MD) yarns that form (i) knuckles extending in substantially MD lines along the structuring fabric, and (ii) substantially continuous lines of pockets extending in substantially MD lines along the structuring fabric between the lines of knuckles and (b) cross machine direction (CD) yarns that are located completely below a plane defined by the knuckles of the MD yarns;
defining a fabric creping percentage by the speed of the transfer surface relative to the speed of the structuring fabric such that the fabric creping percentage is less than about 25%;
causing the web to plow onto the knuckles of the structuring fabric and into the pockets between the knuckles, thereby creating folds in the structure of the web and an indented bar between two of such folds in the web; and
drying the web to form the fabric-creped absorbent cellulosic sheet, wherein the absorbent cellulosic sheet has SAT capacities of at least about 9.5 g/g and at least about 500 g/m 2 .

2. The method according to claim 1 , wherein the fabric creping percentage is about 3% to about 25%.

3. The method according to claim 1 , wherein the SAT capacities of the absorbent cellulosic sheet are at least about 10.0 g/g and at least about 500 g/m 2 .

4. The method according to claim 1 , wherein the basis weight of the absorbent cellulosic sheet is less than about 30 lbs/ream.

5. The method according to claim 1 , wherein the absorbent cellulosic sheet is a multi-ply sheet having a caliper of at least about 220 mils/8 sheets.

6. The method according to claim 5 , wherein the absorbent cellulosic sheet has a basis weight of greater than about 35 lbs/ream and a caliper of greater than about 225 mils/8 sheets.

7. The method according to claim 1 , wherein the absorbent cellulosic sheet has a basis weight of less than about 27 lbs/ream and a caliper of less than about 180 mils/8 sheets.

8. The method according to claim 1 , wherein the structuring fabric has cross machine direction (CD) yarns that are completely located below a plane defined by the knuckles of the MD yarns at a top surface of the structuring fabric.

9. The method according to claim 8 , wherein the MD yarns in the top surface of the structuring fabric slope downwards from a plane defined by the MD knuckles to positions below CD yarns of the structuring fabric.

10. The method according to claim 8 , wherein the length of the knuckles in the MD of the structuring fabric is about 2.2 mm to about 7.5 mm.

11. The method according to claim 10 , wherein the length of the knuckles in the MD of the structuring fabric is about 2.2 mm to about 5.6 mm.

12. The method according to claim 8 , wherein a planar volumetric density index of the structuring fabric multiplied by a ratio of the length of the knuckles and the width of the knuckles is about 43 to about 250.

13. The method according to claim 1 , wherein the transfer surface is part of a backing roll or an endless belt.

14. The method according to claim 1 , wherein the absorbent cellulosic sheet has a first side and a second side, and comprises:
(a) a plurality of domed regions projecting from the first side of the absorbent cellulosic sheet, wherein each domed region is positioned adjacent to another domed region such that a staggered line of domed regions extends substantially along the machine direction (MD) of the absorbent cellulosic sheet, and
(b) connecting regions forming a network interconnecting the domed regions of the absorbent cellulosic sheet, wherein each connecting region is substantially continuous with two other connecting regions such that substantially continuous lines of connecting regions extend in a stepped manner along the MD of the absorbent cellulosic sheet.

15. The method according to claim 14 , wherein each of the domed regions includes a plurality of indented bars extending across the domed regions in the cross machine direction (CD) of the absorbent cellulosic sheet.

16. The method according to claim 15 , wherein at least some of the domed regions includes eight indented bars.

17. The method according to claim 14 , wherein each of the domed regions extends a distance of about 2.5 mm to about 3.0 mm in the MD of the absorbent sheet.

18. The method according to claim 14 , wherein the domed regions are rectangular-shaped.

19. The method according to claim 1 , wherein the structuring fabric has an air permeability of about 450 CFM to about 1000 CFM.

20. The method according to claim 1 , wherein the folds are created in the structure of the web, particularly in areas of the web that are moved into the pockets of the structuring fabric.

21. The method according to claim 1 , further comprising forming multiple indented bars in domed regions of the absorbent cellulosic sheet.

22. The method according to claim 21 , wherein the indented bars are spaced apart about 0.5 mm apart along lengths of the domed regions of the absorbent cellulosic sheet.

23. The method according to claim 22 , wherein the indented bars extend to a depth of about 45 microns to about 160 microns below tops of adjacent areas of the domed regions of the absorbent cellulosic sheet.

24. The method according to claim 21 , wherein the domed regions are bilaterally staggered the MD such that substantially continuous lines of the domed regions extend in the MD of the absorbent cellulosic sheet.

25. The method according to claim 24 , wherein the bilaterally staggered domed regions form a continuous, stepped line, substantially along the MD of the absorbent cellulosic sheet.

26. The method according to claim 25 , wherein the indented bars extend an average (mean) of about 90 microns below tops of adjacent areas of the domed regions of the absorbent cellulosic sheet.

27. The method according to claim 24 , wherein substantially continuous lines of connecting regions extend in a stepped manner along the MD of the absorbent cellulosic sheet.

28. The method according to claim 27 , wherein the sizes of the domed regions and the connecting regions of the absorbent cellulosic sheet generally correspond to the pocket and the knuckle sizes in the structuring fabric.

Assignees

• Gpcp Ip Holdings Llc

Inventors

• Sze Daniel Hue Ming
• Fan Xiaolin
• Chou Hung-Liang
• Oriaran Taiye Philips
• Anand Farminder Singh
• Baumgartner Dean Joseph
• Miller Joseph Henry

Classifications

• D21H27/002 Primary

  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 title

• B31F1/07

  Embossing {, i.e. producing impressions formed by locally deep-drawing, e.g. using rolls provided with complementary profiles}({B31F1/128 takes precedence;} corrugating B31F1/20; embossing in combination with printing B41F19/02, B41M1/24; typewriters for embossing B41J3/38; stamping in combination with deforming B41K3/36) · CPC title

• B31F1/16

  by elastic belts {(B31F1/18 takes precedence)} · CPC title

• D21F7/12

  Drying · CPC title

• D21F11/006 Primary

  Making patterned paper · CPC title