Compressible wood pulp product

• US 6,719,862 B2
• Filed: 05/30/2003
• Issued: 04/13/2004
• Est. Priority Date: 10/09/1998
• Status: Expired due to Fees

• Current Assignee: Weyerhaeuser Company (Weyerhauser)
• Original Assignee: Weyerhaeuser Company (Weyerhauser)
• Inventors: Hansen, Michael R., Young, Richard H. Sr., Shellhammer, Daniel M., Quick, Robert H.
• Primary Examiner(s): Cole, Elizabeth M.
• Assistant Examiner(s): TORRES VELAZQUEZ, NORCA LIZ
• Application Number:
  US10/449,184
• Publication Number:
  US 20030207641A1
• Time in Patent Office: 319 Days
• Field of Search: 156/60, 156/61, 162/164.1, 162/174, 162/175, 162/179, 162/181.1, 162/181.2, 162/183-185, 442/59
• US Class Current: 156/60
• CPC Class Codes: A61F 13/53 characterised by the absorbing medium A61F13/20 takes precedence
• CPC Class Codes: A61F 13/53747 the layer is facing the topsheet layer is part of the topsheet A61F13/511
• CPC Class Codes: D21H 15/02 characterised by configuration
• CPC Class Codes: D21H 17/06 Alcohols; Phenols; Ethers; Aldehydes; Ketones; Acetals; Ketals
• CPC Class Codes: D21H 17/07 Nitrogen-containing compounds
• CPC Class Codes: D21H 17/14 Carboxylic acids; Derivatives thereof
• CPC Class Codes: D21H 17/15 Polycarboxylic acids, e.g. maleic acid
• CPC Class Codes: D21H 17/53 Polyethers; Polyesters
• CPC Class Codes: D21H 17/55 Polyamides; Polyaminoamides; Polyester-amides
• CPC Class Codes: D21H 17/56 Polyamines; Polyimines; Polyester-imides
• CPC Class Codes: D21H 21/14 characterised by function or properties in or on the paper D21H19/66, D21H27/02 take precedence
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 442/20 Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
• CPC Class Codes: Y10T 442/659 Including an additional nonwoven fabric
• CPC Class Codes: Y10T 442/664 Including a wood fiber containing layer
• CPC Class Codes: Y10T 442/674 Nonwoven fabric with a preformed polymeric film or sheet
• CPC Class Codes: Y10T 442/695 Including a wood containing layer
• CPC Class Codes: Y10T 442/696 Including strand or fiber material which is stated to have specific attributes [e.g., heat or fire resistance, chemical or solvent resistance, high absorption for aqueous compositions, water solubility, heat shrinkability, etc.]
• CPC Class Codes: Y10T 442/699 Including particulate material other than strand or fiber material

Abstract

A highly densifiable wood pulp product is disclosed. In one embodiment, the densifiable product includes fibers having low coarseness, preferably having a fiber coarseness less than about 22 mg/100 m, and a densifying agent. In another embodiment, the densifiable product further includes fibers having coarseness greater than about 22 mg/100 m. Juvenile wood fibers are the preferred source of fibers having low coarseness. A densified pulp product formed by compacting a fibrous composite that includes fibers having a fiber coarseness less than about 22 mg/100 m, a densifying agent, and optionally, fibers having coarseness greater than about 22 mg/100 m is also disclosed. The pulp products can be advantageously incorporated into absorbent articles and can optionally further include superabsorbent material. Methods for forming the densifiable and densified fibrous products are also disclosed.

Claims

1. A method for forming a compressible pulp product comprising applying a densifying agent to wood fibers having a fiber coarseness less than about 22 mg/100 m.

2. The method of claim 1 wherein the wood fibers further comprise wood fibers having a fiber coarseness greater than about 22 mg/100 m.

3. A method for forming a densified pulp product comprising:

applying a densifying agent to wood fibers having a fiber coarseness less than about 22 mg/100 m to provide a fibrous web; and

compacting the fibrous web to provide a densified pulp product.

4. The method of claim 3 wherein the wood fibers further comprise wood fibers having a fiber coarseness greater than about 22 mg/100 m.

5. A method for forming a densified pulp product comprising:

forming a fibrous slurry comprising wood fibers having a fiber coarseness less than about 22 mg/100 m;

depositing the fibrous slurry on a foraminous support to form a wet composite;

applying a densifying agent to the wet composite;

drying the wet composite to form a fibrous web; and

densifying the fibrous web.

6. The method of claim 5 wherein the wood fibers further comprise wood fibers having a fiber coarseness greater than about 22 mg/100 m.

7. A method for forming a fibrous sheet product having increased density comprising:

applying a densifying agent to wood fibers having a fiber coarseness less than about 22 mg/100 m to provide a fibrous web; and

compacting the fibrous web to provide a densified fibrous sheet having a density greater than a fibrous sheet formed from compacting a fibrous web composed of wood fibers having a fiber coarseness greater than about 22 mg/100 m and a densifying agent.

8. The method of claim 7 wherein the wood fibers further comprise wood fibers having a fiber coarseness greater than about 22 mg/100 m.