ABSORBENT CORE, ARTICLES COMPRISING SAID CORE, AND METHODS OF MAKING

• US 20190321243A1
• Filed: 12/21/2017
• Published: 10/24/2019
• Est. Priority Date: 12/27/2016
• Status: Active Grant

• Current Assignee: Ontex Nv (Ontex Group NV)
• Original Assignee: Ontex BVBA (Ontex Group NV), Ontex Group NV
• Inventors: WEBER, Ainas, BREU, Manfred, MAILINGER, Christel, HEEGE, Thomas
• Granted Patent: US 10,729,599 B2
• Time in Patent Office: Days
• CPC Class Codes: A61F 13/15634 Making fibrous pads between sheets or webs
• CPC Class Codes: A61F 13/1565 by depositing continuous layers of fibrous material between webs, e.g. wrapping layers of fibrous material
• CPC Class Codes: A61F 13/15658 Forming continuous, e.g. composite, fibrous webs, e.g. involving the application of pulverulent material on parts thereof
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: A61F 13/4756 the means consisting of grooves, e.g. channels, depressions or embossments, resulting in a heterogeneous surface level
• CPC Class Codes: A61F 13/531 having a homogeneous composition through the thickness of the pad A61F13/538, A61F13/539 take precedence
• CPC Class Codes: A61F 13/532 inhomogeneous in the plane of the pad
• CPC Class Codes: A61F 13/533 having discontinuous areas of compression
• 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 13/539 characterised by the connection of the absorbent layers with each other or with the outer layers
• CPC Class Codes: A61F 2013/15926 for vacuum forming
• CPC Class Codes: A61F 2013/423 the alarm being a volume change or a movement of a component
• CPC Class Codes: A61F 2013/530131 being made in fibre but being not pulp
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61F 2013/530868 characterized by the liquid distribution or transport means other than wicking layer A61F13/537 takes precedence
• CPC Class Codes: A61F 2013/53908 with adhesive
• CPC Class Codes: B29D 99/0064 Producing wearing apparel
• CPC Class Codes: B29K 2023/00 Use of polyalkenes or derivatives thereof as moulding material
• CPC Class Codes: B29K 2713/00 Use of textile products or fabrics for preformed parts, e.g. for inserts B29K2105/06 takes precedence
• CPC Class Codes: B32B 37/02 characterised by a sequence of laminating steps, e.g. by adding new layers at consecutive laminating stations
• CPC Class Codes: B32B 37/1018 : using only vacuum
• CPC Class Codes: B32B 37/142 : Laminating of sheets, panels or inserts, e.g. stiffeners, by wrapping in at least one outer layer, or inserting into a preformed pocket
• CPC Class Codes: B32B 37/22 : involving the assembly of both discrete and continuous layers

Abstract

An absorbent core comprising substantially continuous zones of one or more high fluid distribution structures and discontinuous zones of fluid absorption structures surrounding the one or more high fluid distribution structures, wherein the one or more high fluid distribution structures are arranged to distribute fluid across the absorbent core at a speed that is faster than the speed of fluid distribution across the absorbent core by said discontinuous fluid absorption structures, and wherein said continuous zones extend along a path that is substantially parallel to at least a portion of the perimeter of the core, said portion of the perimeter of the core comprising at least a portion of the sides of the core and one of the ends of the core.

Claims

1. An absorbent core (101) comprising:

a front portion (122);

a back portion (124);

a crotch portion (126) position between the front portion (122) and, the back portion (124); and

a longitudinal axis extending along a length of said core (101) and crossing said front, crotch and back portions (122, 126, 124), the absorbent core (101) having a width extending perpendicular to said length and a perimeter comprising at least two opposing ends (102, 103) and at least two opposing sides (104, 105) positioned between said ends (102, 103) characterized in that the absorbent core (101) comprises one or more substantially interconnected channels (106) substantially free of three-dimensional absorbent material extending through the crotch portion (126) along and substantially parallel to the longitudinal axis and thither extending along at least a portion of said width of the core from one side of the core to the other,

wherein at least one of the interconnected channels (106) forms a shape having a closed end in the form of a U-bend, wherein the closed end is positioned proximal to the back portion (124) of the absorbent core (101), and wherein at least one of the interconnected channels (106) forms a shape having an open end in the form of two diverging ends or a funnel-shape, wherein the open end is positioned proximal to the front portion (122) of the absorbent core (101) and distal from said closed end.

2. An absorbent core (101) according to claim 1, wherein at least one of the interconnecting channels (106) comprises:

a first channel portion (107) extending substantially along the longitudinal axis proximal to a first side (104) of the core (101);

a second channel portion (108) extending substantially along the longitudinal axis proximal to a second side (105) of the core (101); and

at least one connecting channel portion (109) in fluid communication with said first and second channel portions (107, 108) and forming said closed, end in the form of a U-bend.

3. An absorbent core (101) according to claim 1 wherein each substantially interconnected channel (106) comprises:

a first channel portion (107) extending substantially along the longitudinal axis proximal to a first side (104) of the core (101);

a second channel portion (108) extending substantially along the longitudinal axis proximal to a second side (105) of the core (101); and

at least one connecting channel portion (109) in fluid communication with said first and second channel portions (107, 108).

4. An absorbent core (101) according to claim 2 wherein the connecting channel portion (109) extends substantially along the width of said core (101), forming a closed end shape within a surface of said core (101) along a plane parallel to the longitudinal axis, and positioned opposite to an open end shape thrilled by non-connected first and second terminal positions (110,111) of the interconnected channel (106) of the first and second channel portions (107, 108) respectively, said non-connected first and second terminal positions (110, 111) being distal to each other and proximal to the first and second sides (104, 105) of said core (101) respectively.

5. An absorbent core (101) according to claim 4 wherein the closed end is substantially curvilinear in shape, forming a convex shape between the first and second channel portions (107, 108), or is substantially linear in shape, forming a straight or triangular shape between the first and second channel portions (107, 108).

6. An absorbent core (101) according to claim 1 having a first distance (d₁) between the first channel portion (107) and the second channel portion (108), a second distance (d₂) between the first channel portion (107) and the second channel portion (108), wherein the first distance (d₁) is proximal to the front portion (102) of the core (101) and the second distance (d₂) is proximal to the back portion (103) of the absorbent core (101), and wherein the first distance (d₁) is greater than the second distance (d₂).

7. An absorbent core (101) according to claim 1 comprising a first nonwoven web;

a second nonwoven web; and

a three-dimensional absorbent material positioned between the first and second nonwoven webs to form an absorbent core laminate, wherein the three-dimensional absorbent material comprises a fibrous web comprising airlaid fibers, and comprises a predetermined amount of super absorbent polymer dispersed therethrough.

8. An absorbent core (101) according to claim 1 wherein the substantially interconnected channels (106) have a regular or irregular depth, said depth being measured on an axis perpendicular to both the longitudinal axis and the axis along the width of the core (101), wherein the cross-section of said channels (106) is selected from the group consisting of curved, polygonal and combinations thereof.

9. An absorbent article (10, 20, 300) comprising a core (101) according to claim 1, said article being selected from disposable diapers or diaper pants;

disposable incontinence diapers or diaper pants;

sanitary napkins; and

panty liners; and

wherein the channels in said core remain visible both before and after use of the article.

12. A process of making an absorbent core (101) according to claim 1 comprising the steps of:

i. providing a mold and comprising a 3D insert therein, said 3D insert being an inverse shape of one or more substantially interconnected channels, wherein substantially the entire surface of the mold is in fluid communication with an under-pressure source except for the 3D insert;

ii. applying a first nonwoven web to said mold;

iii. applying a three-dimensional absorbent material over at least a portion of said nonwoven;

iv. applying a second nonwoven web directly or indirectly over the three-dimensional absorbent material;

v. optionally applying a bonding step to form a laminate comprising said first nonwoven, said second nonwoven and said three-dimensional absorbent material therebetween;

vi. optionally removing said laminate from the mold to form an absorbent core comprising one or more substantially interconnected channels having an inverse shape of said 3D insert; and

wherein at least for the duration of step iii the underpressure source is arranged to provide a vacuum force forcing said three-dimensional absorbent material around the 3D insert such to substantially evacuate the surface thereof from three-dimensional absorbent material and form one or more substantially interconnected channels substantially free of three-dimensional absorbent material.

13. A process according to claim 12 wherein the bonding step comprises applying an adhesive on a surface of the second nonwoven web and joining said web to said first nonwoven web ardor three-dimensional absorbent material, the adhesive being applied in continuous or discontinuous spaced apart stripes aligned with, said channels such that the resulting core laminate comprises adhesive rich and adhesive poor regions, wherein the adhesive rich regions are substantially located along said channels and the adhesive poor regions are located in areas of the core other than said channels.

14. A process according to claim 12 wherein the channels substantially free of absorbent material are formed only by action of said vacuum force and no additional embossing or mating of one or more mating parts or mating strips.

15. An absorbent core (101) according to claim 2, wherein the first and second channel portions (107, 108) diverge away from the longitudinal axis at least, along a portion of the interconnecting channel (106) exiting from the U-bend, thereby at least partially forming a funnel-shaped interconnected channel near the closed end.

16. An absorbent core (101) according to claim 4, wherein said terminal positions (110, 111) face away from each other such to form a funnel-shaped gap therebetween.

17. An absorbent core (101) according to claim 6, wherein the first distance (d₁) is at least 1.5 d₂.

18. An absorbent core (101) according to claim 6, wherein the first distance (d₁) is from 1.8 d₂ to 3 d₂.

19. An absorbent core (101) according to claim 7, wherein the first nomvoven web is in the form of a backsheet and the second nonwoven web is in the form of a topsheet.

20. An absorbent article (10, 20. 300) comprising a core (101) according to claim 9, wherein the channels are more visible, alter use than before use of the article.

10. (canceled)

11. A method of tri-stage fluid distribution in an absorbent article containing a core having substantially interconnected channels, the method comprising:

distributing a first fluid at a first speed, distributing a second fluid at a second speed and distributing a third fluid at a third speed, said first speed being greater or equal to said second speed and said third speed being less than said first speed and less than or equal to said second speed, wherein the first fluid distribution is driven by the substantially interconnected channels, the second fluid distribution is driven by a three-dimensional absorbent material comprised within the core, and the third fluid distribution is driven by an amount of super absorbent polymer dispersed within the three-dimensional absorbent material.