NONWOVEN WEB AND FILTER MEDIA CONTAINING PARTIALLY SPLIT MULTICOMPONENT FIBERS

• US 20100159770A1
• Filed: 12/23/2008
• Published: 06/24/2010
• Est. Priority Date: 12/23/2008
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Myers, David, Reddy, Kiran K., Walser, Susan Kathleen, Frazier, Nina, Zimmerman, Nancy J., Smith, Reginald, Chambers, Leon Eugene JR.
• Granted Patent: US 8,021,996 B2
• Time in Patent Office: Days
• US Class Current: 442/335
• CPC Class Codes: D04H 1/48 in combination with at least one other method of consolidation
• CPC Class Codes: D04H 1/54 by welding together the fibres, e.g. by partially melting or dissolving in combination with needling D04H1/485
• CPC Class Codes: D04H 1/5414 side-by-side
• CPC Class Codes: D04H 1/5418 Mixed fibres, e.g. at least two chemically different fibres or fibre blends
• CPC Class Codes: D04H 3/11 by fluid jet
• CPC Class Codes: D04H 3/153 Mixed yarns or filaments
• CPC Class Codes: D04H 3/16 with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
• CPC Class Codes: Y10T 442/60 Nonwoven fabric [i.e., nonwoven strand or fiber material]
• CPC Class Codes: Y10T 442/608 Including strand or fiber material which is of specific structural definition
• CPC Class Codes: Y10T 442/609 Cross-sectional configuration of strand or fiber material is specified
• CPC Class Codes: Y10T 442/611 Cross-sectional configuration of strand or fiber material is other than circular
• CPC Class Codes: Y10T 442/614 Strand or fiber material specified as having microdimensions [i.e., microfiber]
• CPC Class Codes: Y10T 442/629 Composite strand or fiber material
• CPC Class Codes: Y10T 442/637 Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
• CPC Class Codes: Y10T 442/638 Side-by-side multicomponent strand or fiber material
• CPC Class Codes: Y10T 442/659 Including an additional nonwoven fabric
• CPC Class Codes: Y10T 442/663 Hydroentangled
• CPC Class Codes: Y10T 442/681 Spun-bonded nonwoven fabric
• CPC Class Codes: Y10T 442/689 Hydroentangled nonwoven fabric
• CPC Class Codes: Y10T 442/692 Containing at least two chemically different strand or fiber materials

Abstract

The present invention provides a nonwoven web prepared from multicomponent fibers which are partially split. The partially split multicomponent fibers have at least one component of the multicomponent fiber separated from the remaining components of the multicomponent fiber along a first section of the longitudinal length of the multicomponent fibers. Along a second section of the longitudinal length of the multicomponent fibers the components of the multicomponent fibers remain together as a unitary fiber structure. In addition, part of the second section of the multicomponent fibers is bonded to part of a second section of an adjacent multicomponent fiber.

Claims

1. A nonwoven web comprising multicomponent fibers, the multicomponent fibers having a longitudinal length, each multicomponent fiber having at least a first component and at least a second component, wherein the first component has a lower melting point or glass transition temperature than the second component, a portion of the multicomponent fibers are partially split, where at least one component of the multicomponent fiber has separated from the remaining components of the multicomponent fiber along a first section of the longitudinal length of the multicomponent fibers, along a second section of the longitudinal length of the multicomponent fibers the components of the multicomponent fibers remain together as a unitary fiber structure, and wherein part of the second section of the multicomponent fibers is bonded to part of a second section of an adjacent multicomponent fiber.

2. The nonwoven web according to claim 1, wherein a second portion of the multicomponent fibers are unsplit.

3. The nonwoven web according to claim 1, wherein the nonwoven web is first thermally bonded and then hydroentangled, whereby the hydroentangling of the nonwoven web results in the first portion of multicomponent fibers becoming partially split.

4. The nonwoven web according to claim 3, wherein the multicomponent fibers comprise spunbond fibers, staple fibers or a mixture thereof.

5. The nonwoven web according to claim 3, wherein the multicomponent fibers comprise bicomponent fibers.

6. The nonwoven web according to claim 5, wherein the bicomponent fibers have a side-by-side configuration.

7. The nonwoven web according to claim 5, wherein the bicomponent fibers comprise continuous fibers.

8. The nonwoven web according to claim 3, wherein the portion of the second section of the multicomponent fibers are bonded to an adjacent multicomponent fiber by thru-air bonding.

9. The nonwoven web according to claim 1, wherein the components of the multicomponent fibers are each a thermoplastic polymer selected from the group consisting of polyesters, polyolefins, polyamides, polyacrylates, polymethacrylates, polylactic acid, polyhydroxy alkanates and combinations thereof.

10. The nonwoven web according to claim 5, wherein a first component of the bicomponent fibers is a polyethylene and the second component is a polypropylene.

11. The nonwoven web according to claim 10, wherein the bicomponent fibers comprise 90-10% by weight polyethylene and 10-90% by weight polypropylene.

12. The nonwoven web according to claim 11, wherein the bicomponent fibers comprise 60-40% by weight polyethylene and 40-60% by weight polypropylene.

13. The nonwoven web according to claim 1, wherein the multicomponent fibers are at least partially crimped.

14. The nonwoven web according to claim 1, wherein the multicomponent fibers comprise essentially round fibers.

15. The nonwoven web according to claim 1, wherein the multicomponent fibers comprise shaped fibers.

16. The nonwoven web according to claim 1, wherein the nonwoven web is electret treated.

17. A laminated nonwoven material comprising the nonwoven web according to claim 1 laminated to one or more nonwoven webs selected from the group consisting of spunbond nonwoven webs, meltblown nonwoven webs, bonded carded webs, coform nonwoven webs, and/or hydroentangled nonwoven webs.

35. A method of producing a nonwoven web according to claim 1, said method comprising

forming a nonwoven web comprising multicomponent fibers;

thermally bonding the nonwoven web to form a bonded nonwoven web; and

hydroentangling the bonded nonwoven web at a pressure between about 500 and 3000 psi.

18. A filter media comprising a nonwoven web, the nonwoven web comprising multicomponent fibers, the multicomponent fibers having a longitudinal length, each multicomponent fiber having at least a first component and at least a second component, wherein the first component has a lower melting point or glass transition temperature than the second component, a portion of the multicomponent fibers are partially split, where at least one component of the multicomponent fiber has separated from the remaining components of the multicomponent fiber along a first section of the longitudinal length of the multicomponent fibers, along a second section of the longitudinal length of the multicomponent fibers the components of the multicomponent fibers remain together as a unitary fiber structure, and wherein part of the second section of the multicomponent fibers is bonded to part of a second section of an adjacent multicomponent fiber.

19. The filter media according to claim 18, wherein a second portion of the multicomponent fibers are unsplit.

20. The filter media according to claim 18, wherein the nonwoven web is first thermally bonded and then hydroentangled, whereby the hydroentangling of the nonwoven web results in the first portion of multicomponent fibers becoming partially split.

21. The filter media according to claim 20, wherein the multicomponent fibers comprise spunbond fibers, staple fibers or a mixture thereof.

22. The filter media according to claim 20, wherein the multicomponent fibers comprise bicomponent fibers.

23. The filter media according to claim 22, wherein the bicomponent fibers have a side-by-side configuration.

24. The filter media according to claim 22, wherein the bicomponent fibers comprise continuous fibers.

25. The filter media according to claim 20, wherein the portion of the second section of the multicomponent fibers are bonded to an adjacent multicomponent fiber by thru-air bonding.

26. The filter media according to claim 18, wherein the components of the bicomponent fibers are each a thermoplastic polymer selected from the group consisting of polyesters, polyolefins, polyamides, polyacrylates, polymethacrylates, polylactic acid, polyhydroxy alkanates and combinations thereof.

27. The filter media according to claim 22, wherein a first component of the bicomponent fibers is a polyethylene and the second component is a polypropylene.

28. The filter media according to claim 27, wherein the bicomponent fibers comprise 90-10% by weight polyethylene and 10-90% by weight polypropylene.

29. The filter media according to claim 28, wherein the bicomponent fibers comprise 60-40% by weight polyethylene and 40-60% by weight polypropylene.

30. The filter media according to claim 18, wherein the multicomponent fibers are at least partially crimped.

31. The filter media according to claim 18, wherein the nonwoven web is electret treated.

32. The filter media according to claim 18, wherein the multicomponent fibers comprise essentially round fibers.

33. The filter media according to claim 18, wherein the multicomponent fibers comprise shaped fibers.

34. The filter media according to claim 18, further comprising as least one additional layer laminated to the nonwoven web, the additional layer comprising one or more nonwoven webs selected from the group consisting of spunbond nonwoven webs, meltblown nonwoven webs, bonded carded webs, coform nonwoven webs, and/or hydroentangled nonwoven webs.

36. The method according to claim 33, wherein hydroentangling comprises zoned hydroentangling.

37. The method according to claim 33, wherein thermally bonding comprises thru-air bonding.