Absorbent core, articles comprising said core, and methods of making
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.
1. An absorbent core ( 101 ) comprising:
a front portion ( 122 );
a back portion ( 124 );
a crotch portion ( 126 ) positioned 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 ) extending through the crotch portion ( 126 ) along and substantially parallel to the longitudinal axis and further extending along at least a portion of said width of the core from one side of the core to the other, wherein said one or more substantially interconnected channels ( 106 ) are substantially free of three-dimensional absorbent material and comprises a first nonwoven web bonded to a second nonwoven web by one or more adhesives, and 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 ), and 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, said closed end being substantially curvilinear in shape forming a convex shape between the first and second channel portions ( 107 , 108 ).
2. The absorbent core ( 101 ) according to claim 1 wherein the closed end is positioned opposite to an open end shape formed by non-connected first and second terminal positions ( 110 , 111 ) of the first and second channel portions ( 107 , 108 ) respectively, of the substantially interconnected channel ( 106 ), wherein said non-connected first and second terminal positions ( 110 , 111 ) are distal to each other and proximal to the first and second sides ( 104 , 105 ) of said core ( 101 ) respectively.
3. The absorbent core ( 101 ) according to claim 2 wherein said terminal positions ( 110 , 111 ) face away from each other to form a funnel-shaped gap therebetween.
4. The absorbent core ( 101 ) according to claim 1 having a first distance (d 1 ) between the first channel portion ( 107 ) and the second channel portion ( 108 ), a second distance (d 2 ) between the first channel portion ( 107 ) and the second channel portion ( 108 ), wherein the first distance (d 1 ) is proximal to the front portion ( 122 ) of the core ( 101 ) and the second distance (d 2 ) is proximal to the back portion ( 124 ) of the core ( 101 ), and wherein the first distance (d 1 ) is greater than the second distance (d 2 ).
5. The absorbent core ( 101 ) according to claim 4 , wherein the first distance (d 1 ) is at least 1.5d 2 .
6. The absorbent core ( 101 ) according to claim 4 , wherein the first distance (d 1 ) is from 1.8d 2 to 3d 2 .
7. The absorbent core ( 101 ) according to claim 1 comprising the first nonwoven web; the second nonwoven web; and a three-dimensional absorbent material positioned between the first and second nonwoven webs to form an absorbent core laminate.
8. The absorbent core ( 101 ) according to claim 7 , wherein the first nonwoven web is in the form of a backsheet and the second nonwoven web is in the form of a topsheet.
9. The absorbent core ( 101 ) according to claim 7 , wherein the three dimensional absorbent material comprises a fibrous web.
10. The absorbent core ( 101 ) according to claim 7 , wherein the three dimensional absorbent material comprises a predetermined amount of super absorbent polymer dispersed therethrough.
11. The absorbent core ( 101 ) according to claim 1 comprising a plurality of substantially interconnected channels.
12. The absorbent core ( 101 ) according to claim 11 wherein the plurality of substantially interconnected channels are arranged in a substantially concentric manner.
13. The absorbent core ( 101 ) according to claim 1 further comprising one or more disconnected channels.
14. The absorbent core ( 101 ) according to claim 13 wherein at least a portion of the one or more disconnected channels are arranged concentrically to the one or more substantially interconnected channels.
15. The absorbent core ( 101 ) according to claim 1 wherein the substantially interconnected channels ( 106 ) have a regular depth, said depth being measured on an axis perpendicular to both the longitudinal axis and the axis along the width of the core ( 101 ).
16. The absorbent core ( 101 ) according to claim 1 wherein the cross-section of said channels ( 106 ) is selected from the group consisting of curved, polygonal and combinations thereof.
17. The absorbent core ( 101 ) according to claim 1 wherein the substantially interconnected channels ( 106 ) have an 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 ).
18. The absorbent core ( 101 ) according to claim 1 , wherein said one or more substantially interconnected channels ( 126 ) are symmetric about the longitudinal axis.
19. The absorbent core ( 101 ) according to claim 1 , wherein said one or more substantially interconnected channels ( 126 ) are asymmetric about the longitudinal axis.
20. An absorbent article ( 10 , 20 , 300 ) comprising a core ( 101 ) according to claim 15 , said article being selected from disposable diapers or diaper pants; disposable incontinence diapers or diaper pants; sanitary napkins; and panty liners.
21. The absorbent article ( 10 , 20 , 300 ) according to claim 20 , wherein the channels remain visible both before and after use of the article.
22. The absorbent article ( 10 , 20 , 300 ) according to claim 20 , wherein the channels are more visible after use than before use of the article.