High brightness non-wood pulp

Patent metadata

Field	Value
Publication number	US-2025146219-A1
Application number	US-202519011926-A
Country	US
Kind code	A1
Filing date	Jan 7, 2025
Priority date	Nov 6, 2020
Publication date	May 8, 2025
Grant date	—

Abstract

Disclosed are non-wood pulps having a fiber length greater than about 1.70 mm and a brightness of about 80% or greater. The relatively high degree of brightness is achieved without a loss fiber length or pulp yield. The high degree of brightness and relatively long fiber length makes the pulps well suited for the manufacture of wet-laid fibrous products, particularly wet-laid tissue products. The pulps may be prepared from plants of the family Asparagaceae by mechanical pulping and more preferably by a chemi-mechanical pulping using a sodium hydroxide alkaline peroxide solution where the primary pulp is cleaned to reduce debris prior to bleaching. Preferably the cleaned primary pulp has less than about 5% debris prior to bleaching.

First claim

We claim:

1 . A method of manufacturing a non-wood pulp comprising the steps of:
a. providing a non-wood biomass derived from a plant of the family Asparagaceae; b. cutting the non-wood biomass to a nominal length; c. extracting water soluble solids from the cut biomass to produce bagasse; d. impregnating the bagasse with a first sodium hydroxide alkaline peroxide and maintaining the impregnation for a first reaction time to produce impregnated bagasse; e. feeding the impregnated bagasse to a refiner comprising a refining disc encased in a housing having an inlet and an outlet; f. refining the impregnated bagasse under first refining conditions to produce a primary pulp; g. discharging the primary pulp out of the refining housing through the outlet and adding a second sodium hydroxide alkaline peroxide solution to the discharged primary pulp; h. cleaning the primary pulp to yield a cleaned primary pulp having less than about 5% debris; i. delivering the cleaned primary pulp to a bleaching vessel; and j. adding a third sodium hydroxide alkaline peroxide solution to the cleaned primary pulp in the bleaching vessel to yield a bleached primary pulp having a fiber length greater than about 1.70 mm and a brightness of about 80% or greater.

2 . The method of claim 1 wherein the first sodium hydroxide alkaline peroxide solution comprises at least about 2% peroxide, at least about 1.5% sodium hydroxide, and at least about 1% stabilizer, based upon the dry weight of the bagasse, the second sodium hydroxide alkaline peroxide solution comprises at least about 3% peroxide, at least about 2% sodium hydroxide, and at least about 2% stabilizer, based upon the dry weight of the primary pulp, and the third sodium hydroxide alkaline peroxide solution comprises at least about 5% peroxide and 4% sodium hydroxide, based upon the dry weight of the cleaned primary pulp.

3 . The method of claim 1 wherein the biomass is derived from one or more plants of the genus Hesperaloe.

4 . The method of claim 3 wherein the one or more plants are selected from H. funifera, H. parviflora, H. nocturna, H. chiangii, H. tenuifolia, H. engelmannii and H. malacophylla.

5 . The method of claim 1 further comprising the step of compressing and macerating the bagasse using a plug screw having a compression ratio of at least 2:1.

6 . The method of claim 1 wherein the refiner housing comprises a superatmospheric casing and the step of refining comprises feeding the impregnated bagasse having a consistency from about 20 to about 60% to the refiner and refining at a pressure of at least about 240 kP.

7 . The method of claim 1 wherein the primary pulp temperature is at least about 80° C. when the second sodium hydroxide alkaline peroxide solution is added.

8 . The method of claim 1 further comprising the step of mixing the sodium hydroxide alkaline peroxide solution and the primary pulp after the second sodium hydroxide alkaline peroxide solution is added.

9 . The method of claim 8 wherein the sodium hydroxide alkaline peroxide solution and the primary pulp are mixed for at least one hour.

10 . The method of claim 1 further comprising the steps of washing the bleached primary pulp, thickening the bleached primary pulp and adding a fourth sodium hydroxide alkaline peroxide solution to the washed and thickened bleached primary pulp.

Assignees

• Kimberly Clark Co

Inventors

• Shannon Thomas G
• Ackerly Samantha C
• Yu Zhiying
• Paulson David J
• Wei Ning

Classifications

• D21H11/14

  Secondary fibres (working-up waste paper D21C5/02) · CPC title

• D21D1/20

  Methods of refining · CPC title

• D21C9/163

  with peroxides · CPC title

• D21C3/222

  Use of compounds accelerating the pulping processes · CPC title

• D21C1/02

  with water or steam · CPC title