Process for making a flowable and meterable densified fiber particle

• US 20040079499A1
• Filed: 10/25/2002
• Published: 04/29/2004
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Weyerhaeuser NR Company (Weyerhauser)
• Original Assignee: Weyerhaeuser Company (Weyerhauser)
• Inventors: Dezutter, Ramon C., Hansen, Michael R.
• Granted Patent: US 7,201,825 B2
• Time in Patent Office: Days
• US Class Current: 162/100
• CPC Class Codes: C04B 18/028 temporarily agglomerated, e.g. agglomerates which fall apart during mixing with the other mortar or concrete ingredients
• CPC Class Codes: C04B 18/24 Vegetable refuse, e.g. rice husks, maize-ear refuse; Cellulosic materials, e.g. paper , cork
• CPC Class Codes: C04B 20/02 Treatment
• CPC Class Codes: C04B 20/026 Comminuting, e.g. by grinding or breaking; Defibrillating fibres other than asbestos
• CPC Class Codes: D21B 1/00 Fibrous raw materials or their mechanical treatment pretreatment of the finely-divided materials before digesting D21C1/00; methods of beating or refining pulp D21D1/00; purification of the pulp suspension by mechanical means D21D5/00
• CPC Class Codes: D21B 1/04 by dividing raw materials into small particles, e.g. fibres breaking-up or cutting wood or the like by dry methods B27L; mechanical separation of fibres from plant material D01B1/00; hackling or heckling machines D01B5/00
• CPC Class Codes: D21B 1/14 Disintegrating in mills
• CPC Class Codes: D21F 11/00 Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete

Abstract

Discrete particles of cellulosic material are flowable and meterable. They are easily dispersible in an aqueous or a dry medium. The particles comprise singulated cellulose fibers that have been densified. The particles have a density of at least 0.3 g/cc.

Claims

1. A process for producing a readily dispersible, flowable, and meterable cellulosic product comprising:

singulating cellulose fibers to form a mass of singulated fibers, and

densifying the singulated fibers and forming the fibers into discrete particles, each of said discrete particles comprising a plurality of cellulose fibers mechanically bonded together.

2. The process of claim 1, wherein said fibers are singulated by introducing a sheet of cellulose fibers into a hammermill.

3. The process of claim 1, wherein said fibers are singulated by introducing never dried pulp into a jet drier and drying and singulating the fibers therein.

4. The process of claim 1, wherein said fibers are densified by passing the mass of singulated fibers through a pair of nip rolls to produce a mat of densified fibers.

5. The process of claim 4, wherein said densified fibers are formed into discrete particles by cutting said mat of densified fibers into a plurality of discrete particles.

6. The process of claim 4, wherein said fibers are formed into discrete particles by punching said mat of densified fibers to form discrete particles.

7. The process of claim 1, wherein said fibers are simultaneously densified and formed by introducing said singulated cellulose fibers into a rotary die to form discrete particles.

8. The process of claim 1, wherein said discrete particles have a density of at least 0.3 g/cc.

9. The process of claim 8, wherein said density ranges from 0.3 to 2 g/cc.

10. The process of claim 8, wherein said density ranges from 0.3 to 1 g/cc.

11. The process of claim 8, wherein said particles are generally flat and have a total surface area of at least 10 sq. mm.

12. The process of claim 11, wherein said particles have a surface area of about 10 to about 150 sq. mm.

13. The process of claim 1, further comprising the step of:

dispersing said particles into water, said particles dispersing into singulated fibers in less than one minute with slight agitation.

14. The process of claim 1, wherein said particles have a thickness of 0.5 mm or greater.

15. The process of claim 14, wherein said thickness ranges from 0.5 to 10 mm.

16. The process of claim 1, wherein said cellulose fibers further comprise an adjuvant selected from the group consisting of coupling agents, silicates, zeolites, latices, crosslinkers, debonders, surfactants, dispersants, clays, carbonates, biocides, dyes, antimicrobial compositions, flame retardants, preservatives, synthetic fibers, glass fibers, carbon fibers, and natural fibers.

17. The process of claim 16, wherein the synthetic fibers are selected from the group consisting of polypropylene, polyester, polyamide, polyethylene, rayon, and lyocell.

18. The process of claim 16, wherein the natural fibers are selected from the group consisting of hardwood, softwood, cotton, wool, silk, straw, flax, hemp, jute, bagasse, sisal, kenaf, recycled pulp, OCC, and ONP.