Crosslinkable cellulosic fibrous product

• US 6,572,919 B2
• Filed: 08/30/2001
• Issued: 06/03/2003
• Est. Priority Date: 04/26/1999
• Status: Expired due to Fees

• Current Assignee: Weyerhaeuser Company (Weyerhauser)
• Original Assignee: Weyerhaeuser Company (Weyerhauser)
• Inventors: Westland, John A., Elston, Colin
• Primary Examiner(s): Cole, Elizabeth M.
• Application Number:
  US09/943,902
• Publication Number:
  US 20020031971A1
• Time in Patent Office: 642 Days
• Field of Search: 427/179, 156/152, 156/167, 156/180, 156/296
• US Class Current: 427/179
• CPC Class Codes: A61L 15/225 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 15/28 Polysaccharides or their derivatives A61L15/225 takes precedence
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: D04H 1/64 the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
• CPC Class Codes: D21C 9/005 organic compounds
• CPC Class Codes: D21H 11/16 modified by a particular after-treatment
• CPC Class Codes: D21H 25/06 of impregnated or coated paper D21H25/08 takes precedence
• 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 442/241 Coating or impregnation improves snag or pull resistance of the fabric
• CPC Class Codes: Y10T 442/2484 Coating or impregnation is water absorbency-increasing or hydrophilicity-increasing or hydrophilicity-imparting
• CPC Class Codes: Y10T 442/2738 Coating or impregnation intended to function as an adhesive to solid surfaces subsequently associated therewith
• CPC Class Codes: Y10T 442/277 Coated or impregnated cellulosic fiber fabric
• CPC Class Codes: Y10T 442/2828 Coating or impregnation contains aldehyde or ketone condensation product
• CPC Class Codes: Y10T 442/2869 Coated or impregnated regenerated cellulose fiber fabric
• CPC Class Codes: Y10T 442/697 Containing at least two chemically different strand or fiber materials

Abstract

A crosslinkable cellulosic fibrous product that includes cellulosic fibers and a crosslinking agent is disclosed. The crosslinkable cellulosic fibrous product can be formed as a web or sheet that has structural integrity and sheet strength sufficient to permit the fibrous web to be rolled, transported, and used in rolled form in subsequent processes. The crosslinkable fibrous product can be converted into a crosslinked fibrous product by subjecting the product to conditions sufficient to effect intrafiber crosslinking. Alternatively, the web can be fiberized and the resulting individual crosslinkable fibers combined with other fibers and/or other materials to provide a fibrous web containing crosslinkable cellulosic fibers. Subjecting such a web to crosslinking conditions provides a fibrous web that includes, in addition to other fibers or materials, crosslinked cellulosic fibers.

Claims

1. A method for forming a crosslinkable fibrous product comprising:

applying a crosslinking agent to a fibrous cellulosic sheet;

drying the fibrous sheet to provide a fibrous product comprising substantially noncrosslinked cellulosic fibers; and

forming the fibrous sheet into a rolled sheet.

2. A method for forming a crosslinked cellulosic product comprising:

conveying a crosslinkable fibrous sheet into a fiberizer, wherein the crosslinkable fibrous sheet comprises cellulosic fibers and a crosslinking agent, wherein the sheet comprises substantially noncrosslinked fibers, and wherein the sheet is a rolled sheet;

separating the fibrous sheet into individualized fibers in the fiberizer, wherein the individualized fibers comprise fibers coated with the crosslinking agent; and

heating the individualized fibers to cure the crosslinking agent to provide intrafiber crosslinked cellulosic fibers.

3. The method of claim 2 further comprising applying a crosslinking catalyst to the crosslinkable fibrous sheet.

4. A method for forming a crosslinked cellulosic product comprising:

conveying a crosslinkable fibrous sheet into a fiberizer, wherein the crosslinkable fibrous sheet comprises cellulosic fibers and a crosslinking agent, wherein the sheet comprises substantially noncrosslinked fibers, and wherein the sheet is a rolled sheet;

separating the fibrous product into individualized fibers in the fiberizer, wherein the individualized fibers comprise fibers coated with the crosslinking agent;

forming a fibrous sheet comprising the individualized fibers; and

subjecting the fibrous sheet to conditions sufficient to cure the crosslinking agent to provide a fibrous sheet comprising intrafiber crosslinked cellulose fibers.

5. The method of claim 4 wherein forming a fibrous sheet comprises combining the individualized fibers with a fiber selected from the group consisting of groundwood fibers, bleached pulp fibers, unbleached pulp fibers, recycled wood fibers, secondary wood fibers, hemp fibers, bagasse fibers, and cotton fibers.

6. The method of claim 4 wherein subjecting the fibrous sheet to conditions sufficient to form intrafiber crosslinked cellulosic fibers comprises heating to cure the crosslinking agent.

7. The method of claim 4 wherein subjecting the fibrous sheet to conditions sufficient to form intrafiber crosslinked cellulosic fibers comprises applying a crosslinking catalyst to the crosslinkable fibrous sheet and heating to cure the crosslinking agent.

8. The method of claim 4 wherein subjecting the fibrous sheet to conditions sufficient to form intrafiber crosslinked cellulosic fibers comprises adjusting the pH of the crosslinkable fibrous sheet and heating to cure the crosslinking agent.