Paper products and pulps with surface enhanced pulp fibers and increased absorbency, and methods of making same

Patent metadata

Field	Value
Publication number	US-11441271-B2
Application number	US-201916267755-A
Country	US
Kind code	B2
Filing date	Feb 5, 2019
Priority date	Feb 5, 2018
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

Paper products such as tissues can be made using a furnish comprising surface enhanced pulp fibers (“SEPF”). In some embodiments, SEPF have a weighted average fiber length of at least 0.3 millimeters (mm) and an average hydrodynamic specific surface area of at least 10 square meters per gram (m2/g). In some embodiments, a furnish or a paper product can comprise at least 2 % SEPF by dry weight. In some embodiments, a paper product comprising SEPF can be formed from a furnish having a freeness of 650 ml Canadian Standard Freeness (CSF) or less, optionally 600 ml CSF or less.

First claim

The invention claimed is:

1. A method of manufacturing tissue, the method comprising:
mixing at least a first pulp and a second pulp to generate a furnish, wherein:
the first pulp comprises surface enhanced pulp fibers having a length weighted average fiber length of at least 0.3 millimeters (mm) and an average hydrodynamic specific surface area of at least 10 square meters per gram (m 2 /g);
the second pulp comprises softwood fibers; and
mixing is performed such that the furnish comprises from 10% to 25% surface enhanced pulp fibers by dry weight of fiber in the furnish; and

beating, with a refiner, the furnish such that the furnish has a freeness less than or equal to 650 milliliters Canadian Standard Freeness (ml CSF).

2. The method of claim 1 , wherein beating is performed such that the furnish has a freeness of 600 ml CSF or less.

3. The method of claim 2 , wherein beating is performed such that the furnish has a freeness between 550 ml CSF and 600 ml CSF.

4. The method of claim 1 , wherein mixing is performed such that the furnish comprises between 5% and 25% surface enhanced pulp fibers by dry weight of fiber in the furnish.

5. The method of claim 1 , comprising forming one or more sheets of tissue using the furnish such that the sheet(s) have a grammage between 20 and 45 grams per square meter (g/m 2 ).

6. The method of claim 1 , wherein the softwood fibers of the second pulp comprise Northern bleached softwood kraft fibers.

7. The method of claim 1 , wherein beating is performed such that a decrease in the freeness of the furnish is less than or equal to 300 ml CSF.

8. The method of claim 7 , wherein beating is performed such that a decrease in the freeness of the furnish is less than or equal to 150 ml CSF.

Assignees

• Pande Harshad
• Coffin Douglas W
• Alinejad Mona
• Domtar Paper Co Llc
• Univ Miami

Inventors

• Pande Harshad
• Coffin Douglas W
• Alinejad Mona

Classifications

• D21H27/007

  relating to absorbency, e.g. amount or rate of water absorption, optionally in combination with other parameters relating to physical or mechanical properties · CPC title

• D21H27/002

  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 title

• D21H11/10 Primary

  Mixtures of chemical and mechanical pulp · CPC title

• D21D1/00

  Methods of beating or refining; Beaters of the Hollander type (knotter screens D21F) · CPC title

• D21H15/02

  characterised by configuration · CPC title