Absorbent article and absorbent core forming channels when wet

• US 10,071,002 B2
• Filed: 06/05/2014
• Issued: 09/11/2018
• Est. Priority Date: 06/14/2013
• Status: Active Grant

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Bianchi, Ernesto Gabriel, Ehrnsperger, Bruno Johannes, Hollenberg, Doris, Rinnert, Thorsten
• Primary Examiner(s): Stephens, Jacqueline
• Application Number:
  US14/296,483
• Publication Number:
  US 20140371701A1
• Time in Patent Office: 1,559 Days
• CPC Class Codes: A61F 13/5323 having absorbent material located in discrete regions, e.g. pockets
• CPC Class Codes: A61F 13/534 having an inhomogeneous composition through the thickness of the pad A61F13/538, A61F13/539 take precedence; homogeneous cores with tissue wrapping A61F13/53
• 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 13/53743 characterised by the position of the layer relative to the other layers
• CPC Class Codes: A61F 13/53747 the layer is facing the topsheet layer is part of the topsheet A61F13/511
• CPC Class Codes: A61F 2013/530445 by defining a target or acquisition or vulnerability zone
• CPC Class Codes: A61F 2013/530452 having chemically-stiffened fibres
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61F 2013/5349 being a tissue-wrapped core
• CPC Class Codes: A61F 2013/53778 with grooves

Abstract

An absorbent article for personal hygiene comprising a liquid permeable topsheet, a liquid impermeable backsheet, an absorbent core and a fibrous layer. The absorbent core comprises a core wrap and an absorbent material with superabsorbent polymers. The core wrap comprises a top side and a bottom side bonded to one other through one or more areas substantially free of absorbent material. The fibrous layer is at least partially bonded to one of the sides of the core wrap in the area substantially free of absorbent material. When the absorbent material swells, the core wrap forms one or more channels along the area substantially free of absorbent material. The formation of the channel in the absorbent core causes the formation of one or more corresponding ditches in the fibrous layer.

Claims

1. An absorbent article comprising:

a liquid permeable topsheet,

a liquid impermeable backsheet,

an absorbent core between the topsheet and backsheet, the absorbent core comprising a core wrap enclosing an absorbent material, the absorbent material comprising a superabsorbent polymer,

wherein the core wrap comprises a top side and a bottom side,

wherein the absorbent core comprises one or more areas substantially free of absorbent material through which the top side of the core wrap is attached to the bottom side of the core wrap, so that when the absorbent material swells the core wrap forms one or more channels along the areas substantially free of absorbent material, and wherein the absorbent core is void of areas substantially free of absorbent material which are transversely oriented; and

the absorbent article further comprising a fibrous layer, wherein the fibrous layer is at least partially bonded to the top side or the bottom side of the core wrap in the area substantially free of absorbent material such that the fibrous layer at least partially fills the area substantially free of absorbent material, so that the formation of the channel in the absorbent core as the absorbent material swells causes the formation of one or more corresponding ditches in the fibrous layer.

2. An absorbent article according to claim 1 wherein the fibrous layer is between the topsheet and the absorbent core, and the fibrous layer is at least partially bonded to the top side of the core wrap in the area substantially free of absorbent material.

3. An absorbent article according to claim 1 wherein the absorbent material comprises at least about 50% of superabsorbent polymer by weight of the absorbent material.

4. An absorbent article according to claim 3 wherein the absorbent material comprises from about 80% to about 100% of superabsorbent polymer by weight of the absorbent material.

5. An absorbent article according to claim 1 wherein the absorbent core comprises from about 10 g to about 50 g of superabsorbent polymer.

6. An absorbent article according to claim 1 wherein the absorbent core comprises at least a pair of areas substantially free of absorbent material and wherein these areas are symmetrically disposed relative to the longitudinal axis.

7. An absorbent article according to claim 1 wherein at least one of the areas substantially free of absorbent material has a length projected on the longitudinal axis of the article which is at least about 10% of the length of the absorbent article.

8. An absorbent article according claim 1, wherein at least one of the areas substantially free of absorbent material has a width in at least in some part of the area of at least about 2 mm.

9. An absorbent article according claim 8, wherein the width is from about 4 mm to about 14 mm.

10. An absorbent article according to claim 1 wherein the core wrap comprises a first nonwoven substantially forming the top side of the core wrap and a second nonwoven substantially forming the bottom side of the core wrap.

11. An absorbent article according to claim 10 wherein the first nonwoven forms a C-wrap around the second nonwoven.

12. An absorbent article according to claim 1 wherein the fibrous layer comprises at least about 50% by weight of cross-linked cellulose fibers.

13. An absorbent article according to claim 1 wherein the topsheet is directly or indirectly attached to the fibrous layer in the area of the one or more ditches.

14. An absorbent article according to claim 1, wherein the periphery of the absorbent material within the core wrap defines an absorbent material deposition area, and wherein the absorbent material deposition area is rectangular or is shaped with a width narrower at the crotch point than the maximum width of the absorbent material deposition area in the rest of the core, wherein the crotch point is defined as the point placed at a distance of two fifth of L from the front edge of the absorbent article on the longitudinal axis.

15. An absorbent article according to claim 1 wherein the absorbent core comprises a first absorbent layer and a second absorbent layer, the first absorbent layer comprising a first substrate and a first layer of superabsorbent polymers, the second absorbent layer comprising a second substrate and a second layer of superabsorbent polymers, and a fibrous thermoplastic adhesive material at least partially bonding each layers of superabsorbent polymers to their respective substrate, the first substrate and the second substrate forming the core wrap.

16. An absorbent article according to claim 1 wherein the absorbent core has an absorbent material loss of no more than about 70% according to the Wet Immobilization Test described herein.

17. An absorbent article according to claim 1 comprising an additional layer between the topsheet and the fibrous layer.

18. An absorbent article according to claim 17 wherein the additional layer is an acquisition layer and the topsheet is attached to the additional layer in one or more attachment areas that at least partially overlap with the area substantially free of absorbent material of the core.

19. An absorbent article according to claim 1 wherein the core wrap bond of the channels of the absorbent core opens in a controlled manner during use, so that when the absorbent core is immersed in a saline solution at 0.9% by weight at 37°

C. according to the Channel Delamination Dunk Test described herein;

less than about one third of the core wrap bond'"'"'s initial length delaminates at 10 min;

from about one third to about two thirds of the core wrap bond'"'"'s initial length delaminates at 20 min; and

at least about two thirds of the core wrap bond'"'"'s initial length delaminates at 60 min.

20. An absorbent article according to claim 1 wherein the core wrap bond of the channels of the absorbent core opens in a controlled manner during use, so that when the absorbent core is immersed in a saline solution at 0.9% by weight at 37°

C. according to the Channel Delamination Dunk Test described herein;

less than about one third of the core wrap bond'"'"'s initial length delaminates at 10 min; and

at least about two thirds of the core wrap bond'"'"'s initial length delaminates at 60 min.