Absorbent members having improved fluid distribution via low density and basis weight acquisition zones

• US 5,348,547 A
• Filed: 04/05/1993
• Issued: 09/20/1994
• Est. Priority Date: 04/05/1993
• Status: Expired due to Term

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Payne, Michael, Perkins, Robert W., Moore, Danny R.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): CLARKE, ROBERT A
• Application Number:
  US08/042,950
• Time in Patent Office: 533 Days
• Field of Search: 604/358, 604/383, 604/378, 604/379
• US Class Current: 604/378
• CPC Class Codes: A61F 13/49009 with elastic means
• CPC Class Codes: A61F 13/51 characterised by the outer layers wicking or transfer layers A61F13/537
• CPC Class Codes: A61F 13/535 inhomogeneous in the plane of the pad, e.g. core absorbent layers being of different sizes A61F13/5323, A61F13/537 take precedence
• CPC Class Codes: A61F 13/53717 the layer having a promotional function on liquid propagation in the horizontal direction
• CPC Class Codes: A61F 13/53747 the layer is facing the topsheet layer is part of the topsheet A61F13/511
• CPC Class Codes: A61F 13/5376 characterised by the performance of the layer, e.g. acquisition rate, distribution time, transfer time
• CPC Class Codes: A61F 13/58 Adhesive tab fastener elements A61F13/5611, A61F13/5616, A61F13/66 take precedence
• CPC Class Codes: A61F 2013/15406 Basis weight
• 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 2013/4581 with absorbent core in separated pieces
• CPC Class Codes: A61F 2013/49082 being a complex shape not covered by the other groups A61F2013/49068-A61F2013/4908
• CPC Class Codes: A61F 2013/51409 being a film
• CPC Class Codes: A61F 2013/51411 being impervious to fluids but not for air or vapours
• CPC Class Codes: A61F 2013/530007 being made from pulp
• CPC Class Codes: A61F 2013/530131 being made in fibre but being not pulp
• CPC Class Codes: A61F 2013/530357 of wool
• CPC Class Codes: A61F 2013/53043 with different ratio of components
• CPC Class Codes: A61F 2013/530445 by defining a target or acquisition or vulnerability zone
• CPC Class Codes: A61F 2013/530459 being curled
• CPC Class Codes: A61F 2013/530467 : being twisted
• CPC Class Codes: A61F 2013/530474 : being cross-linked
• CPC Class Codes: A61F 2013/530481 : having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61F 2013/530569 : characterized by the particle size
• CPC Class Codes: A61F 2013/5307 : characterized by the quantity or ratio of superabsorbent material
• CPC Class Codes: A61F 2013/530905 : being hydrophilic
• CPC Class Codes: A61F 2013/53726 : on the top layer
• CPC Class Codes: A61F 2013/53795 : being a surge management layer
• CPC Class Codes: A61F 2013/588 : on waist panels

Abstract

An absorbent article having a dual-layer absorbent member, wherein the deposition region of its upper acquisition layer comprises a distribution zone and an acquisition zone having a lower average density and a lower average basis weight per unit area than the distribution zone. 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 lower storage layer 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 dual-layer absorbent member. The upper acquisition layer comprises a homogeneous composition of stiffened, twisted, and curled cellulose fibers which provide enhanced wicking action in the densified distribution zone. The upper acquisition layer serves to rapidly and evenly distribute fluids to the lower storage layer for storage, while freeing the acquisition zone for the next discharge of fluid.

Claims

1. A multi-layer 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) at least one storage layer comprising a mixture of hydrophilic fibrous material and discrete particles of absorbent gelling material, said storage layer having a first top surface area; and

(b) at least one acquisition layer positioend in fluid communication with said storage layer, said acquisition layer havinq a front edqe at least partially overlying said front section and a back edqe at least pattially overlying said back section, said acquisition layer further having two opposed side edqes extendinq between said front edge and said back edge, said acquisition layer comprising a homogeneous composition of hydrophilic fibrous material, said homogeneous composition comprising stiffened, twisted, and curled cellulose fibers, said acquisition layer comprising an acquisition zone for acquiring fluids having a first density and a first average basis weight, said acquisition zone being positioned at least pattially within said deposition region, said acquisition layer further comprising a densified distribution zone for distributing fluids in liquid communication with said acquisition zone at a density interface, said density interface extending generally transversely across said acquisition layer from one side edge to the opposite side edge, said distribution zone having a second average density which is at least about 2.0 times said first average density and a second average basis weight which is at least about 2.0 times said first average basis weight, and said acquisition layer having a second top surface area which is between about 0.7 and about 1.0 times said first top surface area;

whereby fluid introuduced into siad acquisiton layer via said acquisition zone is drawn across said density interface and into said distribution zone via capillary action and subsequently distributed to said storage layer.

2. The absorbent member of claim 1, wherein said storage layer comprises between about 30% and about 60% by weight of said particles of absorbent gelling material.

3. The absorbent member of claim 2, wherein said storage layer comprises about 40% by weight of said particles of absorbent gelling material.

4. The absorbent member of claim 1, wherein said second average density is at least about equal to 2.5 times said first average density.

5. The absorbent member of claim 4, wherein said second average density is about equal to 3.0 times said first average density, and wherein said acquisition layer has a uniform overall thickness.

6. The absorbent member of claim 1, wherein said acquicition zone comprises less than about 50% of said second top surface area.

7. The absorbent member of claim 6, wherein said acquisition zone comprises less than about 35% of said second top surface area.

8. The absorbent member of claim 7, wherien said acquisiton zone comprises about 30% of said second top surface area.

9. The absorbent member of claim 1, wherein said acquisition layer consists essentially of a homogeneous composition of stiffened, twisted, and curled cellulose fibers.

10. 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.

11. A multi-layer 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 betwee said end region and said back section, the absorbent member comprising:

(a) at least one storage layer comprising a mixture of hydrophilic fibrous material and discrete particles of absorbent gelling material having a mass median particle size ranging from about 400 microns to about 1410 microns, said storage layer having a first top surface area; and

(b) at least one acquisition layer positioned in overlying spaced relation to said storage layer so as to be positioned between a wearer and said storage layer, said acquisition layer havinq a front edge at least partially overlying said front section and a back edqe at least partially overlying said back section, said acquisition layer further havinq two opposed side edges extending between said front edqe and said back edge, said acquisition layer comprising a homogeneous composition of hydrophilic fibrous material, said homogeneous composition comprising stiffened, twisted, and curled cellulose fibers, said acquisition layer comprising an acquisition zone for acquiring fluids having a first density and a first average basis weight, said acquisition zone being positioned at least partially within said deposition region, said acquisition layer further comprising a densified distribution zone for distributinq fluids in liquid communication with said acquisition zone at a density interface, said density interface extending generally transversely across said acquisition layer from one side edge to the opposite side edge, said distribution zone having a second average density which is about 3.0 times said first average density and a second average basis weight which is about 3.0 times said first average basis weight, and said acquisition layer having a second top surface area which is about 0.75 times said first top surface area, said acquisition zone comprising about 30% of said second top surface area, said acquisition layer further having a uniform overall thickness;

whereby fluid introduced into said acquisition layer via said acquisition zone is drawn across said density interface and into said distribution zone via capillary action and subsequently distributed to said storage layer.

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

(a) a backsheet; and

(b) a multi-layer absorbent member positioned adjacent to said backsheet, said absorbent member comprising at least one storage layer comprising a mixture of hydrophilic fibrous material and discrete particles of absorbent gelling material, said storage layer having a first top surface area, said absorbent member further compri sing at least one acquisition layer positioned in fluid communication with said storage layer, said acquisition layer having a front edge generally adjacent to said front waistband region and a back edge generally adjacent to said back waistband region, said acquisition layer further having two opposed side edges extending between said front edge and said back edge said acquisition layer comprising a homogeneous composition of hydrophil ic fibrous material, said homogeneous composition comprising stiffened, twisted, and curled cellulose fibers, said acquisition layer comprising an acquisition zone for acquiring fluids, said acquisition zone being positioned with respect to the absorbent article such that said acquisition zone is at least partially positioned in said crotch region, said acquisition zone having a first density and a first average basis weight, said acquisition zone being positioned in said deposition region, said acquisition layer further comprising a densified distribution zone for distributing fluids in 1 iquid communication with said acquisition zone at a density interface, said density interface extending general ly transversely across said acquisition layer from one side edge to the opposite side edge, said distribution zone having a second average density which is at leust about 2.0 times said first average density and a second average basis weight which is at least about 2.0 times said first average basis weight, and said acquisition layer having a second top surface area which is between about 0.7 and about 1.0 times said first top surface area;

whereby fluid introduced into said acquisition layer via said acquisition zone is drawn across said density interface and into said distribution zone via capillary action and subsequently distributed to said storage layer.

13. The absorbent article of claim 12, wherein said storage layer comprises between about 30% and about 60% by weight of said particles of absorbent gelling material.

14. The absorbent article of claim 13, wherein said storage layer comprises about 40% by weight of said particles of absorbent gelling material.

15. The absorbent article of claim 12, wherein said second average density is at least about equal to 2.5 times said first average density.

16. The absorbent article of claim 15, wherein said second average density is about equal to 3.0 times said first average density, and wherein said acquisition layer has a uniform overall thickness.

17. The absorbent article of claim 12, wherein said acquisition zone comprises less than about 50% of said second top surface area.

18. The absorbent article of claim 17, wherein said acquisition zone comprises about 30% of said second top surface area.

19. The absorbent article of claim 12, wherein said absorbent article further comprises a topsheet associated with said backsheet such that said absorbent member is positioned between said topsheet and said backsheet.

20. The absorbent article of claim 12, wherein said particles of absorbent gelling material have a mass median particle size ranging from about 400 microns to about 1410 microns.