Transfer layer for absorbent article
View Patent ↗Three-dimensional formed films particularly useful as transfer layers in absorbent articles comprise a base plane having land areas defining a plurality of protuberances having sidewalls and a bottom wall, a plurality of the protuberances having an aperture in substantially at least one sidewall. In preferred embodiment, the film further comprises a plurality of capillaries, which can originate in the base plane or in a secondary plane spaced from the base plane. In preferred embodiments, the capillaries terminate in a common plane with the bottom surfaces of the protrusions.
1. A three-dimensional formed film comprising protuberances, each protuberance having sidewalls and a bottom wall, the protuberances originating on a first surface of the film, the sidewalls being oriented nominally perpendicular to the first surface of the film and nominally parallel to a z-direction axis of the film, the bottom wall being disposed substantially perpendicular to the sidewalls, a plurality of the protuberances having an aperture in at least one sidewall, the aperture having an average cross-sectional area greater than 0.2 mm 2 and an average hydraulic diameter between 0.55 mm and 1.2 mm; said three-dimensional film further comprising a first plurality of capillaries, said first plurality of capillaries having an average diameter of 50 microns to 400 microns, wherein the average length of the capillaries, as measured in a z-axis direction of the film, is substantially equal to or greater than an average length of the sidewalls.
2. The three-dimensional formed film of claim 1 , wherein the first plurality of capillaries originate from the first surface.
3. The three-dimensional formed film of claim 2 , wherein the first plurality of capillaries terminate in a common plane with the bottom wall of the protuberances.
4. The three-dimensional formed film of claim 1 , wherein at least some of the first plurality of capillaries originate from a surface different from the protuberances.
5. The three-dimensional formed film of claim 4 , wherein the first plurality of capillaries terminate in a common plane with the bottom wall of the protuberances.
6. The three-dimensional formed film of claim 1 , wherein the film further comprises a raised plateau region and wherein said first plurality of capillaries originates from said raised plateau region.
7. The three-dimensional formed film of claim 6 , wherein the plateau region is raised relative to the first surface of the film, said film further comprising a second plurality of capillaries originating from said first surface.
8. The three-dimensional formed film of claim 7 , wherein the first plurality of capillaries, the second plurality of capillaries and the bottom wall of the protrusions all terminate in a common plane.
9. The three-dimensional formed film of claim 1 , wherein no more than 5% of the surface area of the bottom wall is occupied by the aperture.
10. The three-dimensional formed film of claim 1 , said film comprising a thermoplastic polymer.
11. The three-dimensional formed film of claim 10 , wherein the thermoplastic polymer is selected from polyolefins made from olefin monomers having up to 10 carbon atoms; polyesters; plastomers; polyamides (e.g., nylon); polystyrenes; polyurethanes; vinyl polymers; acrylic and/or methacrylic polymers; elastomers (e.g., styrene block copolymer elastomers); polymers from natural renewable sources; biodegradable polymers; and mixtures or blends thereof.
12. The three-dimensional formed film of claim 1 , wherein said film has an energy gradient.
13. The three-dimensional formed film of claim 1 , wherein the formed film comprises two layers, wherein each layer comprises a thermoplastic polymer.
14. The three-dimensional formed film of claim 4 , wherein at least a portion of the capillaries originate from a secondary surface of said film, said secondary surface being spaced from the first surface in a z-direction.
15. The three-dimensional formed film of claim 14 , wherein the first surface comprises continuous lands defining said protuberances and wherein said secondary surface comprises an elevated plateau of discontinuous lands defining said capillaries.
16. An absorbent article, comprising a topsheet; a transfer layer; an absorbent core; and a backsheet; wherein the transfer layer comprises protuberances originating on a first surface of the film, the sidewalls being oriented nominally perpendicular to the first surface of the film and nominally parallel to a z-direction axis of the film, the bottom wall being disposed substantially perpendicular to the sidewalls, a plurality of the protuberances having an aperture in at least one sidewall, the aperture having an average cross-sectional area greater than 0.2 mm 2 and an average hydraulic diameter between 0.55 mm and 1.2 mm; said three-dimensional film further comprising a first plurality of capillaries, said first plurality of capillaries having an average diameter of 50 microns to 400 microns, wherein the average length of the capillaries, as measured in a z-axis direction of the film, is substantially equal to or greater than an average length of the sidewalls.
17. The absorbent article of claim 16 , wherein the capillaries terminate in a common plane with the bottom wall of the protrusions.