Absorbent article with a slitted absorbent core

• US 8,785,715 B2
• Filed: 06/12/2008
• Issued: 07/22/2014
• Est. Priority Date: 06/12/2007
• Status: Active Grant

• Current Assignee: Dsg Technology Holding Limited
• Original Assignee: Dsg Technology Holding Limited
• Inventors: Wright, Andrew, Tsang, Patrick King Yu
• Primary Examiner(s): Stephens, Jacqueline F.
• Application Number:
  US12/138,112
• Publication Number:
  US 20090062760A1
• Time in Patent Office: 2,231 Days
• Field of Search: 604/378, 604/379, 604/380, 604/383
• US Class Current: 604/378
• CPC Class Codes: A61F 13/15642 by depositing continuous layers or pads of fibrous material on single sheets or webs
• CPC Class Codes: A61F 13/15723 Partitioning batts; Cutting
• CPC Class Codes: A61F 13/15731 Treating webs, e.g. for giving them a fibrelike appearance, e.g. by embossing
• CPC Class Codes: A61F 13/15747 Folding; Pleating; Coiling; Stacking; Packaging
• CPC Class Codes: A61F 13/4704 having preferential bending zones, e.g. fold lines or grooves
• CPC Class Codes: A61F 13/49001 having preferential bending zones, e.g. fold lines or grooves
• CPC Class Codes: A61F 13/53409 having a folded core
• CPC Class Codes: A61F 13/537 characterised by a layer facilitating or inhibiting flow in one direction or plane, e.g. a wicking layer A61F13/538 takes precedence
• CPC Class Codes: A61F 13/53713 the layer having a promotional function on liquid propagation in the vertical direction
• 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 13/538 characterised by specific fibre orientation or weave
• CPC Class Codes: A61F 2013/15406 Basis weight
• CPC Class Codes: A61F 2013/15504 with a porosity gradient in the vertical or horizontal plane
• CPC Class Codes: A61F 2013/4568 three-dimensional; with split absorbent core
• CPC Class Codes: A61F 2013/530226 with polymeric fibres
• CPC Class Codes: A61F 2013/530343 being natural fibres
• CPC Class Codes: A61F 2013/530489 being randomly mixed in with other material
• CPC Class Codes: A61F 2013/530496 being fixed to fibres
• CPC Class Codes: A61F 2013/5307 characterized by the quantity or ratio of superabsorbent material
• CPC Class Codes: A61F 2013/53782 : with holes
• CPC Class Codes: A61F 2013/53791 : being resilient or elastic
• CPC Class Codes: B32B 2038/045 : Slitting
• CPC Class Codes: B32B 2333/04 : Polymers of esters
• CPC Class Codes: B32B 2367/00 : Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2555/02 : Diapers or napkins
• CPC Class Codes: B32B 38/04 : Punching, slitting or perforating
• CPC Class Codes: Y10T 156/1026 : with slitting or removal of material at reshaping area prior to reshaping
• CPC Class Codes: Y10T 156/1082 : Partial cutting bonded sandwich [e.g., grooving or incising]
• CPC Class Codes: Y10T 29/49826 : Assembling or joining

Abstract

The invention relates to slit absorbent articles and the use of slits in absorbent materials to provide improved liquid intake rate, flexibility and softness compared to the unmodified material. The absorbent material, including superabsorbent materials, are particularly useful as absorbent cores in disposable absorbent articles such as diapers, incontinent products, sanitary napkins and the like.

Claims

1. An absorbent article having a front waist region, a back waist region, and a crotch region extending longitudinally between said front and back waist regions, said article comprising:

a liquid impervious back sheet; and

an absorbent core comprising;

at least one absorbent layer of comprising superabsorbent material and a plurality of slits disposed in the at least one absorbent layer, said plurality of slits extending through at least a portion of the at least one absorbent layer, said plurality of slits facilitating greater liquid intake of said at least one absorbent layer as compared to an identical, but non-slitted, layer, and further facilitating improved flexibility of the at least one absorbent layer in a predetermined direction;

wherein the absorbent core comprises from about 61% to about 97% by weight of a superabsorbent material, from about 3% to about 39% by weight of non-absorbent nonwoven resilient fibers, and 0% by weight of absorbent hydrophilic fibers, wherein the superabsorbent material comprises particles and the non-absorbent nonwoven resilient fibers form a low-density layer and a high-density layer.

2. The absorbent article of claim 1 wherein at least some of the plurality of slits extend from a top surface of the at least one absorbent layer towards the back sheet.

3. The absorbent article of claim 2 further comprising at least one of a top sheet and an acquisition layer.

4. The absorbent article in claim 1 wherein said plurality of slits comprise a slit level greater than 0.1 cm⁻

1 wherein said slit level is determined at least by a total perimeter of said plurality of slits normalized to a planar area of said absorbent core.

5. The absorbent article of claim 1 wherein said absorbent layer has a basis weight from about 50 grams per square meter (gsm) to about 1000 gsm.

6. The absorbent article of claim 5 wherein said absorbent material layer has a basis weight from about 100 gsm to about 500 gsm.

7. The absorbent article of claim 1 wherein the at least one absorbent layer is folded along at least one region of material discontinuity.

8. The absorbent article in claim 1 wherein said at least one absorbent layer is subjected to a mechanical softening process.

9. The absorbent article in claim 1 wherein the at least one absorbent layer is folded along two or more lines of material discontinuity, wherein said two or more lines are oriented in a product longitudinal direction and located about a central region of the absorbent article, thereby defining an hourglass shape.

10. The absorbent article in claim 1 with the absorbent core further comprising:

another absorbent layer comprising superabsorbent material, said another absorbent layer having substantially fewer slits as compared to the at least one absorbent layer.

11. The absorbent article of claim 1 wherein said plurality of slits comprise a slit width of between 1 micron and 1000 microns to support a capillary flow of liquid into an interior of the at least one absorbent layer.

12. The absorbent article of claim 11 wherein more than one of said plurality of slits extend along a substantial portion of a side of the absorbent core.

13. The absorbent article of claim 12 wherein said more than one of said plurality of slits extend longitudinally between said front waist region and said back waist region.

14. The absorbent article of claim 11, wherein the plurality of slits comprises a slit width between about 1 micron and about 500 microns.

15. The absorbent article of claim 1, wherein the plurality of slits comprises a first group of slits in a first bend area and a second group of intersecting slits in a second bend area, wherein the first group is spaced apart from the second group.

16. A disposable absorbent article having a front waist region, a back waist region, and a crotch region extending longitudinally between said front and back waist regions, said article comprising:

an absorbent core comprising;

from about 61% to about 97% by weight of a superabsorbent material, from about 3% to about 39% by weight of non-absorbent nonwoven resilient fibers, and 0% by weight of absorbent hydrophilic fibers;

and a first absorbent layer comprising a modified region, said modified region having a higher fluid intake rate as compared to an unmodified region;

wherein said modified region comprises a plurality of slits disposed in said first absorbent layer, said plurality of slits extending through at least a portion of said first absorbent layer, said slits promoting the higher fluid intake rate in at least the modified region;

wherein the superabsorbent material comprises particles and the non-absorbent nonwoven resilient fibers form a low-density layer and a high-density layer.