# US 2021/0340710 A1 · Layered tissue comprising long, high-coarseness wood pulp fibers

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- Number: US 2021/0340710 A1
- Document ID: US20210340710A1
- Status: Published application
- Kind: A1
- Application number: 17/284,606
- Filed: 2019-01-18
- Published: 2021-11-04
- Earliest claimed: 2019-01-18
- Assignees: Kimberly-Clark Worldwide, Inc.
- Applicants: Kimberly-Clark Worldwide, Inc.
- Inventors: Thomas Gerard Shannon; Stephen Michael Lindsay; Brent Merrik Thompson; Richard Louis Underhill
- Web page: https://patentgrep.com/patent/US20210340710A1

## CPC

- D21H 27/38: at least one of the sheets having a fibrous composition differing from that of other sheets
- D21F 11/14: Making cellulose wadding, filter or blotting paper
- D21H 11/04: Kraft or sulfate pulp
- D21H 15/02: characterised by configuration
- D21H 21/52: Additives of definite length or shape
- 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)}
- D21H 27/30: Multi-ply (for surface covering D21H27/18; making on paper-making machines D21F9/00, D21F11/00)
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21F: PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON

## Abstract

The present invention provides multi-layered tissue webs, and tissue product comprising the same, comprising long, high-coarseness wood pulp fibers selectively deposited in one or more outer layers of the multi-layered web. Surprisingly disposing long, high-coarseness wood pulp fibers in one or more outer layers, even in relatively modest amounts, may improve certain product properties, such as durability, without negatively affecting softness. In certain instances, both the softness and durability may be improved by selectively incorporating long, high-coarseness wood pulp fibers in one or more of the outer layers.

## Claims

### Claim 1

A tissue product comprising at least one multi-layered tissue web having a first and a second outer layer and a middle layer disposed there between, wherein the first and the second outer layers comprise from about 5 to about 20 weight percent (wt %) long, high-coarseness fiber having an average fiber length greater than about 2.0 mm and a coarseness of 20 mg/100 m or greater, the tissue product having a geometric mean tensile (GMT) from about 700 to about 1,200 g/3″ and a TS7 value less than about 12.0 dB V2 rms.

### Claim 2 (depends on 1)

The tissue product of claim 1 wherein the middle layer is substantially free from long, high-coarseness fiber having an average fiber length greater than about 2.0 mm and a coarseness of 20 mg/100 m or greater.

### Claim 3 (depends on 1)

The tissue product of claim 1 wherein the long, high-coarseness fiber is derived from P. taeda, P. elliotti, P. palustris, P. pungens, P. rigida, P. serotina, P. muricata or P. radiata, and combinations thereof.

### Claim 4 (depends on 1)

The tissue product of claim 1 wherein the long, high-coarseness fiber has an average fiber length from about 2.0 to about 3.0 mm.

### Claim 5 (depends on 1)

The tissue product of claim 1 having a GMT from about 700 to about 1,000 g/3″ and a stiffness index from about 5.0 to about 8.0.

### Claim 6 (depends on 1)

The tissue product of claim 1 having a GMT from about 700 to about 1,000 g/3″ and a durability index greater than about 3.75.

### Claim 7 (depends on 1)

The tissue product of claim 1 having a GM Tear from about 10.0 to about 15.0 gf.

### Claim 8 (depends on 1)

The tissue product of claim 1 having a GM TEA from about 9.0 to about 13.0 g*cm/cm2.

### Claim 9 (depends on 1)

The tissue product of claim 1 having Wet Burst of about 100 gf or greater.

### Claim 10 (depends on 1)

The tissue product of claim 1 wherein the tissue product comprises from about 50 to about 70 wt % short, low-coarseness fiber having an average fiber length less than 1.2 mm and a coarseness less than 20 mg/100 m.

### Claim 11 (depends on 10)

The tissue product of claim 10 wherein the short, low-coarseness fiber is a hardwood kraft pulp fiber derived from Acacia, Eucalyptus, Maple, Oak, Aspen, Birch, Cottonwood, Alder, Ash, Cherry, Elm, Hickory, Poplar, Gum, Walnut, Locust, Sycamore or Beech.

### Claim 12 (depends on 1)

The tissue product of claim 1 wherein the long, high-coarseness fiber has a ratio of average fiber length, having units of mm, to coarseness, having units of mg/100 m, of about 0.12 or less.

### Claim 13 (depends on 12)

The tissue product of claim 12 having a TS7 value from about 10.0 to about 12.0 dB V2 rms.

### Claim 14

A method of forming a soft and durable wet laid tissue product comprising the steps of:
a. providing a first fiber furnish consisting essentially of short wood pulp fibers having an average fiber length less than 1.2 mm and long, high-coarseness fiber having an average fiber length greater than about 2.0 mm and a coarseness of 20 mg/100 m or greater;
b. providing a second fiber furnish comprising long, low-coarseness wood pulp fibers having an average fiber length greater than about 2.0 mm and a coarseness less than 20 mg/100 m;
c. depositing the first fiber furnish on a forming fabric to form a first fabric contacting layer;
d. depositing the second fiber furnish adjacent to the first fiber contacting layer to form a middle layer;
e. depositing the first fiber furnish adjacent to the middle layer to form a first air contacting layer;
f. partially dewatering the wet tissue web;
g. drying the tissue web; and
h. converting the tissue web into a tissue product having a GMT from about 700 to about 1,200 g/3″ and a TS7 value less than about 12.0 dB V2 rms.

### Claim 15 (depends on 14)

The method of claim 14 wherein the converting step comprises calendering, embossing, printing, winding, slitting, plying, perforating, or combinations thereof.

### Claim 16 (depends on 14)

The method of claim 14 wherein the long, high-coarseness fiber are kraft pulp fibers derived from P. taeda, P. elliotti, P. palustris, P. pungens, P. rigida, P. serotina, P. muricata or P. radiata, and combinations thereof, and wherein the product comprises from 5 to 20 wt % long, high-coarseness fiber.

### Claim 17 (depends on 14)

The method of claim 14 wherein the drying step comprises through-air drying the tissue web.

### Claim 18 (depends on 14)

The method of claim 14 wherein the drying step comprises pressing the tissue web onto a heated cylinder and creping the dried web from the cylinder.

### Claim 19 (depends on 14)

The method of claim 14 wherein the long, high-coarseness fiber has an average fiber length from about 2.0 to about 3.0 mm and a coarseness from about 22 mg/100 m to 25 mg/100 m.

### Claim 20 (depends on 14)

The method of claim 14 wherein the short wood pulp fibers comprise hardwood kraft pulp fibers and the long, low-coarseness wood pulp fibers comprise northern softwood kraft fibers and wherein the middle layer is substantially free from long, high-coarseness fiber having an average fiber length greater than about 2.0 mm and a coarseness of 20 mg/100 m or greater.