IP Library Granted Patent US 11,473,242
Granted Patent B2
US 11,473,242 · App. 16/372,317 · Granted Oct 18, 2022

Treated pulp and methods of making and using same

Inventor: Andre Stephan Hajnal (Anderson Island, WA)
Assignee: INTERNATIONAL PAPER COMPANY
D21C9/002D21C9/18D21H17/06D21H21/06
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Quick Facts
Patent No.
US 11,473,242
App. No.
16/372,317
Granted
Oct 18, 2022
Kind
B2
Abstract

Treated pulp sheets comprising cellulose pulp fibers treated with a densifying agent and having a relatively low moisture content. In certain embodiments, the treated pulp sheets are used to produce fiberized pulp having low knot content, while maintaining density and softness properties usually associated with similarly treated pulp that is fiberized at higher moisture content. Methods of making fiberized pulp from the treated pulp sheets, as well as products comprising the treated pulp sheets or fiberized pulp from the treated pulp sheets, are also provided.

Claims (25)

1. A pulp sheet comprising:

hydrogen-bonded cellulose pulp fibers treated with a densifying agent,

wherein the densifying agent is glycerin,

wherein the densifying agent is present in the pulp sheet in an amount from 1 to 9 weight percent,

wherein the pulp sheet, when fiberized at a moisture content from 0 to 9 percent in accordance with a fiberization test, produces a fiberized pulp having a knots level of less than 11.2%, wherein the fiberization test is performed using a laboratory scale Kamas Laboratory Mill, Model H01 hammermill instrumented to measure power necessary to fiberize a given weight of pulp, equipped with a screen having 19 millimeter (mm) round holes, breaker bar clearance of the hammermill is set to 4.0 mm, rotor speed is adjusted to 3024 revolutions per minute (rpm), and pulp feed rate is 2.80 grams/second at 5.0 cm wide pulp sheet, and

wherein a pad of the fiberized pulp has a Carver density equal to or greater than 0.2 g/cm 3 at 150 psi.

2. The pulp sheet of claim 1 , wherein the densifying agent is present in the pulp sheet in an amount from 5 to 9 weight percent.

3. The pulp sheet of claim 1 , wherein the densifying agent is present in the pulp sheet in an amount from 7 to 9 weight percent.

4. The pulp sheet of claim 1 , wherein said knots level is exhibited when the pulp sheet is fiberized at a moisture content from 5 to 9 percent in accordance with the fiberization test.

5. The pulp sheet of claim 4 , wherein said knots level is exhibited when the pulp sheet is fiberized at a moisture content from 6 to 8 percent in accordance with the fiberization test.

6. The pulp sheet of claim 1 , wherein the pulp sheet has a basis weight of at least 300 g/m 2 .

7. The pulp sheet of claim 1 , wherein the pad of the fiberized pulp has a Carver density from 0.2 to 0.3 g/cm 3 at 150 psi.

8. The pulp sheet of claim 1 , wherein a pad of the fiberized pulp has a cantilever stiffness from 4.0 to 8.0 cm, as tested with a basis weight of 600-700 gsm, the pad formed without SAP, and a pad density of 0.12 g/cc.

9. A pulp product, comprising:

the pulp sheet of claim 1 , wherein the pulp sheet is packaged in packaging configured to maintain the moisture content of the pulp sheet at a desired level from 0 to 9 percent.

10. The pulp product of claim 9 , wherein the moisture content of the pulp sheet is from 0 to 9 percent.

11. The pulp product of claim 9 , wherein the moisture content of the pulp sheet is from 5 to 9 percent.

12. A pulp sheet comprising:

hydrogen-bonded cellulose pulp fibers treated with a densifying agent,

wherein the densifying agent is glycerin,

wherein a pad of fiberized pulp of the pulp sheet has a Carver density equal to or greater than 0.2 g/cm 3 at 150 psi,

wherein the pad of fiberized pulp of the pulp sheet has a property selected from the group consisting of a Carver density from 0.2 to 0.3 g/mm3 at 150 psi and a Cantilever stiffness from 4.0 to 8.0 cm, wherein the pad has a basis weight of 600-700 gsm, wherein the pad is formed without SAP, and wherein the pad has a density of 0.12 g/cc,

wherein the densifying agent is present in the pulp sheet in an amount from 1 to 9 weight percent, and

wherein the pulp sheet has a moisture content from 0 to 9 percent.

13. The pulp sheet of claim 12 , wherein a fiberized pulp produced by fiberizing the pulp sheet according to a fiberization test has a knots level of about 3% to about 11.2%, wherein the fiberization test is performed using a laboratory scale Kamas Laboratory Mill, Model H01 hammermill instrumented to measure power necessary to fiberize a given weight of pulp, equipped with a screen having 19 millimeter (mm) round holes, breaker bar clearance of the hammermill is set to 4.0 mm, rotor speed is adjusted to 3024 revolutions per minute (rpm), and pulp feed rate is 2.80 grams/second at 5.0 cm wide pulp sheet.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 14, 2025
From: INTERNATIONAL PAPER COMPANY
To: GCF US HOLDINGS LLC
Reel/Frame 073563/0717 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 9, 2021
From: HAJNAL, ANDRE STEPHAN
To: INTERNATIONAL PAPER COMPANY
Reel/Frame 056485/0780 →
Continuity (1)
Related Publication 20200308766A1 · Oct 1, 2020