Sanitary napkin with improved liquid retention capability

• US 6,515,195 B1
• Filed: 01/04/2000
• Issued: 02/04/2003
• Est. Priority Date: 08/16/1999
• Status: Expired due to Term

• Current Assignee: Edgewell Personal Care Brands, LLC (Edgewell Personal Care Company)
• Original Assignee: Johnson & Johnson
• Inventors: Murji, Zulfikar, Mongeau, Sylvain, Nguyen, Vu Hien, Rosenfeld, Leonard G., Lariviere, Christiane, Mohmad, Roya
• Primary Examiner(s): Lewis, Aaron J.
• Assistant Examiner(s): PLUCINSKI, JAMISUE A
• Application Number:
  US09/477,313
• Time in Patent Office: 1,127 Days
• Field of Search: 604/367, 604/370, 604/371, 604/372, 604/374, 604/375, 604/378-380, 604/385.01, 604/385-3-3, 604/385.101, 604/386, 604/387, 604/389, 604/383
• US Class Current: 604/380
• CPC Class Codes: A61F 13/15203 Properties of the article, e.g. stiffness or absorbency chemical aspects A61L15/00

Abstract

The invention provides a sanitary absorbent article, such as a feminine protection device, having a fibrous, liquid permeable body-facing cover layer, and an absorbent system, which exhibits particular rewet characteristics when subjected to mechanical stress. The sanitary absorbent article has a thickness of less than or equal to 5 mm, a capacity of at least 18 grams, a rewet potential of less than or equal to 0.8 grams, and a flexural resistance of less than 700 g.

Claims

1. A sanitary napkin adapted to be worn in a crotch portion of an undergarment comprising a fibrous fluid-permeable, body-facing cover layer and an absorbent system adjacent said cover layer for receiving liquid therefrom, said napkin having a thickness of about 5 mm or less, a capacity of at least 18 grams, a rewet potential of less than or equal to 0.8 grams as measured by the Procedure for Measuring Rewet Potential described herein and a flexural resistance of less than 700 grams.

2. A sanitary napkin as claimed in claim 1, wherein said rewet potential is less than about 0.5 g.

3. A sanitary napkin as claimed in claim 2, wherein said rewet potential is less than about 0.3 g.

4. A sanitary napkin as claimed in claim 1, wherein said absorbent system includes superabsorbent material.

5. A sanitary napkin as claimed in claim 4, wherein said absorbent system includes a blend of cellulosic fibers and superabsorbent material.

6. A sanitary napkin as claimed in claim 5, wherein said absorbent system comprises a first absorbent layer and a second absorbent layer, said second absorbent layer having a basis weight of from about 100 g/m² to about 700 g/m² which has been air-laid as a bottom layer of pulp, a middle layer of pulp intermixed with superabsorbent polymer, and a top layer containing at least some pulp.

7. A sanitary napkin as claimed in claim 6, wherein said second absorbent layer has a density of more than about 0.25 g/cc.

8. A sanitary napkin as claimed in claim 7, wherein said second absorbent layer has a density in the range from about 0.3 g/cc to about 0.5 g/cc.

9. A sanitary napkin as claimed in claim 8, wherein said second absorbent layer has a density in the range from about 0.3 g/cc to about 0.45 g/cc.

10. A sanitary absorbent napkin as claimed in claim 6, wherein the middle layer comprises a first middle layer adjacent the bottom layer and a second middle layer adjacent the top layer.

11. A sanitary napkin as claimed in claim 6, wherein said second absorbent layer includes from about 20 weight percent to about 55 weight percent suberabsorbent polymer.

12. A sanitary napkin as claimed in claim 11, wherein said second absorbent layer includes from about 30 weight percent to about 45 weight percent superabsorbent polymer.

13. A sanitary napkin as claimed in claim 12, wherein said second absorbent layer includes about 40 weight percent superabsorbent polymer.

14. A sanitary napkin as claimed in claim 6, wherein said second absorbent layer has a basis weight in the range from about 150 g/m² to about 350 g/m².

15. A sanitary napkin as claimed in claim 14, wherein said second absorbent layer has a basis weight in the range from about 200 g/m² to about 300 g/m².

16. A sanitary napkin as claimed in claim 15, wherein said second absorbent layer has a basis weight of about 250 g/m².

17. A sanitary napkin as claimed in claim 6, wherein said first absorbent layer is air laid over said second absorbent layer.

18. A sanitary napkin as claimed in claim 17, wherein said first absorbent layer comprises thermoplastic fibers.

19. A sanitary napkin as claimed in claim 17, wherein said first absorbent layer comprises a material having a density in the range from about 0.04 to 0.05 g/cc.

20. A sanitary napkin as claimed in claim 17, wherein said first absorbent layer comprises a material having a basis weight in the range from about 80 g/m² to about 110 g/m².

21. A sanitary napkin as claimed in claim 18, wherein said first absorbent layer has a thickness in the range from about 2 mm to about 3 mm.

22. A sanitary napkin as claimed in claim 6, wherein said second absorbent layer includes from about 5 weight percent to about 60 weight percent superabsorbent polymer.

23. A sanitary napkin as claimed in claim 22, having an elongate channel formation arranged to direct liquid there along for subsequent absorption into said absorbent system, wherein said elongate channel formation is formed by applying pressure to at least one of said cover layer and said absorbent system.

24. A sanitary napkin as claimed in claim 23, wherein said elongate channel formation is formed by applying heat to at least one of said cover layer and said absorbent system.

25. A sanitary napkin as claimed in claim 1, having an elongate channel formation arranged to direct liquid there along for subsequent absorption into said absorbent system.

26. A sanitary napkin as claimed in claim 25, wherein said elongate channel formation is arcuate in a plane parallel to said absorbent system.

27. A sanitary napkin as claimed in claim 25, wherein said elongate channel formation is formed in at least one of said cover and said absorbent system.

28. A sanitary napkin as claimed in claim 25, further comprising a plurality of said elongate channel formations spaced apart from each other.

29. A sanitary napkin as claimed in claim 28, wherein said elongate channel formations intersect each other.

30. A sanitary napkin as claimed in claim 25, wherein said channels comprise a floor and sides, the floor of said channel having a higher density than at least one side of said channel.

31. A sanitary napkin as claimed in claim 1, wherein, at the interface between said cover and said absorbent system, an elongate region is recessed in said absorbent system, said elongate region having a higher density than a second region adjacent thereto.

32. A sanitary napkin as claimed in claim 31, further comprising a plurality of said elongate regions.

33. A sanitary napkin as claimed in claim 1, further comprising a sheet of material disposed adjacent said second absorbent layer and away from said cover layer and being substantially impervious to liquid to be absorbed by said second absorbent layer.

34. A sanitary napkin as claimed in claim 1, wherein the thickness of the sanitary napkin is less than about 3 mm.

35. A sanitary napkin as claimed in claim 34, wherein the thickness of the sanitary napkin is about 2.8 mm.

36. A sanitary napkin as claimed in claim 1, further comprising a fastener for fastening said napkin to a garment of the wearer.

37. A sanitary napkin as claimed in claim 36, wherein said fastener comprises an adhesive fastener.

38. A sanitary napkin as claimed in claim 37, further comprising a flap carrying said adhesive fastener.