Absorbent members having low density and basis weight acquisition zones

• US 5,047,023 A
• Filed: 02/11/1991
• Issued: 09/10/1991
• Est. Priority Date: 07/18/1986
• Status: Expired due to Term

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Berg, Charles J.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): REICHLE, KARIN M
• Application Number:
  US07/656,101
• Time in Patent Office: 211 Days
• Field of Search: 604/358, 604/364, 604/365, 604/367, 604/368, 604/371, 604/372, 604/374, 604/378-382, 604/385.1, 604/385.2
• US Class Current: 604/368
• CPC Class Codes: A61F 13/511 Topsheet, i.e. the permeable cover or layer facing the skin
• CPC Class Codes: A61F 13/533 having discontinuous areas of compression
• CPC Class Codes: A61F 13/53747 the layer is facing the topsheet layer is part of the topsheet A61F13/511
• CPC Class Codes: A61F 13/53752 the layer is embedded in the absorbent core
• CPC Class Codes: A61F 2013/1543 with a density gradient in the horizontal plane
• CPC Class Codes: A61F 2013/15536 with a capillarity gradient in the vertical or horizontal plane
• CPC Class Codes: A61F 2013/530445 by defining a target or acquisition or vulnerability zone
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61F 2013/53051 being only in particular parts or specially arranged
• CPC Class Codes: A61F 2013/53795 being a surge management layer

Abstract

An absorbent article wherein the deposition region of its absorbent member comprises a storage zone and an acquisition zone having a lower average density and a lower average basis weight per unit area than the storage area. The acquisition zone is positioned toward the front of either the absorbent member or the absorbent article so that the acquisition zone may most effectively and efficiently rapidly acquire discharged liquids. The absorbent member comprises a mixture of hydrophilic fibrous material and discrete particles of absorbent gelling material having a particular size distribution so as to enhance the absorbent capacity and acquisition rate of the absorbent member. The particles of absorbent gelling material are selected to have a mass median particle size greater than or equal to about 400 microns with the amounts of very large and very small particles preferably kept below certain minimum concentrations.

Claims

1. An absorbent member having a back section and a front section contiguous with said back section, said front section having an end region and a deposition region contiguous with said end region and said back section so that said deposition region is positioned between said end region and said back section, the absorbent member comprising:

a storage zone positioned in at least said deposition region of the absorbent member; and

an acquisition zone positioned in at least said deposition region of the absorbent member, said acquisition zone having a lower average density and a lower average basis weight per unit area than said storage zone, said storage zone at least partially laterally surrounding the perimeter of said acquisition zone so as to be in liquid communication with at least a portion of the lateral area of said acquisition zone; and

a mixture of hydrophilic fibrous material and discrete particles of absorbent gelling material, said particles of absorbent gelling material having a mass median particle size ranging from about 400 microns to about 1680 microns.

2. The absorbent member of claim 1 wherein said particles of absorbent gelling material have a mass median particle size ranging from about 400 microns to about 1410 microns.

3. The absorbent member of claim 2 wherein no more than about 16% by weight of said particles have a particle size less than 200 microns.

4. The absorbent member of claim 3 wherein no more than about 16% by weight of said particles have a particle size greater than 1410 microns.

5. The absorbent member of claim 1 wherein said particles of absorbent gelling material have a mass median particle size ranging from about 400 microns to about 1190 microns.

6. The absorbent member of claim 5 wherein said particles of absorbent gelling material have a mass median particle size greater than or equal to about 420 microns.

7. The absorbent member of claim 5 wherein said particles of absorbent gelling material have a mass median particle size greater than or equal to about 500 microns.

8. The absorbent member of claims 1, 2, 5, 6, or 7 wherein said acquisition zone is completely positioned within said deposition region, comprises less than about 35% of the top surface area of said front section, and is transversely centered within said deposition region.

9. The absorbent member of claim 1 wherein no more than about 16% by weight of said particles have a particle size less than 200 microns.

20. An absorbent article comprising:

a liquid pervious topsheet;

a liquid impervious backsheet associated with said topsheet; and

an absorbent member according to claims 1, 3, 10, or 14 positioned between said topsheet and said backsheet.

10. An absorbent member having a back section and a front section contiguous with said back section, said front section having an end region and a deposition region contiguous with said end region and said back section so that said deposition region is positioned between said end region and said back section, the absorbent member comprising:

a storage zone positioned in at least said deposition region of the absorbent member;

an acquisition zone positioned in at least said deposition region of the absorbent member, said acquisition zone having a lower average density and a lower average basis weight per unit area than said storage zone, said storage zone at least partially laterally surrounding the perimeter of said acquisition zone so as to be in liquid communication with at least a portion of the lateral area of said acquisition zone; and

a mixture of hydrophilic fibrous material and discrete particles of absorbent gelling material, said particles of absorbent gelling material having a mass median particle size ranging from about 841 microns to about 1680 microns.

11. The absorbent member of claim 10 wherein said acquisition zone is completely positioned within said deposition region, comprises less than about 35% of the top surface area of said front section, and is transversely centered within said deposition region.

12. The absorbent member of claim 11 wherein said storage zone and said acquisition zone extend through only a fraction of the total thickness of the absorbent member so as to form a dusting layer.

13. The absorbent member of claim 12 wherein said dusting layer and said acquisition zone have the same density and basis weight, and both said dusting layer and said acquisition zone consist essentially of hydrophilic fibrous material.

14. The absorbent member of claims 10, 11, or 12 wherein between 0% and about 20% by weight of said particles have a particle size less than about 841 microns.

15. The absorbent member of claims 10, 11, or 12 wherein said particles of absorbent gelling material have a mass median particle size ranging from about 841 microns to about 1410 microns.

16. The absorbent member of claims 10, 11, or 12 wherein said particles of absorbent gelling material have a mass median particle size ranging from about 841 microns to about 1190 microns.

17. The absorbent member of claim 16 wherein between 0% and about 20% by weight of said particles have a particle size less than about 841 microns, and no more than about 16% by weight of said particles have a particle size greater than about 1190 microns.

18. The absorbent member of claim 11 wherein the top surface area of said acquisition zone has a triangular shape.

19. The absorbent member of claim 11 wherein the top surface of said acquisition zone is fox-shaped.

21. An absorbent article having a front waistband region, a back waistband region and a crotch region, said absorbent article comprising:

a liquid pervious topsheet;

a liquid impervious backsheet associated with said topsheet; and

an absorbent member positioned between said topsheet and said backsheet, said absorbent member comprising a storage zone and an acquisition zone having a lower average density and a lower average basis weight per unit area than said storage zone, said acquisition zone being positioned with respect to the absorbent article such that the top surface area of said acquisition zone is at least partially positioned in said crotch region, said absorbent member comprising a mixture of hydrophilic fibrous material and discrete particles of absorbent gelling material, said particles of absorbent gelling material having a mass median particle size ranging from about 400 microns to about 1190 microns.

22. The absorbent article of claim 21 additionally comprising an absorbent acquisition core positioned between said topsheet and said absorbent member.

23. The absorbent article of claim 22 wherein said absorbent member is generally oblong and has a top surface area that is from about 0.25 to about 1.0 times that of said absorbent acquisition core, said absorbent member being positioned relative to said backsheet and said absorbent acquisition core in a manner such that at least 75% of the absorbent gelling material in said absorbent member is found within the front two-thirds portion of the absorbent article.

24. The absorbent article of claim 21 wherein said particles of absorbent gelling material have a mass median particle size greater than or equal to about 420 microns.

25. The absorbent article of claim 21 wherein said particles of absorbent gelling material have a mass median particle size greater than or equal to about 500 microns.

26. The absorbent article of claims 24 or 25 wherein no more than about 16% by weight of said particles have a particle size less than 210 microns, and no more than about 16% by weight of said particles have a particle size greater than about 1190 microns.