Surgery – Means and methods for collecting body fluids or waste material – Absorbent pad for external or internal application and...
Reexamination Certificate
2002-11-08
2004-01-13
Lo, Weilun (Department: 3761)
Surgery
Means and methods for collecting body fluids or waste material
Absorbent pad for external or internal application and...
C604S385010
Reexamination Certificate
active
06677498
ABSTRACT:
BACKGROUND OF THE INVENTION
To prevent leakage of body exudates from absorbent articles such as feminine care pads or napkins and disposable diapers, it is desirable that the exudates not reach the edges of the absorbent material in the article. A “center fill” strategy is desirable for leakage control, wherein fluids are preferentially held in a central region of the article. Unfortunately, in traditional absorbent articles, there is generally no barrier to bulk flow or capillary wicking from the target region to the edges of the article, so leaking from the edges of the article is a persistent problem. Thus, in traditional articles, fluid entering the center of the article still has the potential to travel to the sides and leak. Flow from the center to the sides can be especially rapid when the article is compressed, bringing the wet central portion of the article in contact with absorbent material at the sides of the article.
What is needed is an article with good center fill performance that can reduce leakage to the sides of the article. Further, the article should offer excellent body fit through a three-dimensional topography that becomes more pronouncedly three-dimensional when the article is worn and compressed between the legs of the wearer while still maintaining comfort.
SUMMARY OF THE INVENTION
It has been discovered that improved body fit and leakage control can be obtained in absorbent articles by providing an absorbent core comprising an outer absorbent member and a central absorbent member operatively associated with a central rising member. The central rising member, described more fully hereafter, is an element which deflects upwards when laterally compressed from the side. The central absorbent member is operatively associated with the central rising member such that the upward deflection of the central rising member also causes the central absorbent member to deflect upward (i.e., toward the source of fluid exudates to be absorbed). In addition, a wicking barrier is incorporated between the outer absorbent member and central absorbent member. The wicking barrier can be an impermeable film or a liquid pervious web offering substantial resistance to wicking and flow.
Desirably, the wicking barrier has a vertical component spanning a vertical distance between the central absorbent member and the outer absorbent member, and also desirably, has a horizontal component spanning a distance on the body-side surface of the outer absorbent member.
The horizontal component or “ledge” that is part of the wicking barrier in preferred embodiments helps prevent contact between the outer absorbent member and the central absorbent member when the article is bunched together during use. The combination of improved body fit due to the action of the central rising member and the fluid isolation of the central absorbent member by the wicking barrier results in a particularly efficient absorbent article with reduced potential for leakage. The wicking barrier can also help control the geometry of the absorbent article when in use under dynamic conditions, permitting flexure or folding such that the central absorbent member is deflected toward the body. When the outer absorbent member is provided with a central void, as hereinafter described, the wicking barrier desirably lines all or a portion of the walls of the central void.
The ledge can also provide increased stability, strength, and resiliency to an absorbent article. This is particularly so when the ledge is adhesively or otherwise attached to the cover or topsheet of an absorbent article and/or to one or more elements of the absorbent core. A problem in some previous attempts at providing isolated chambers in an absorbent article is that a film or other barrier between adjacent chambers eliminates the fiber—fiber bonding or entanglement between fibers that holds an absorbent core together, resulting in an absorbent core which can come apart in tension or compression or during bending. In preferred embodiments of the present invention, the ledge of the wicking barrier is easily attached to the cover and can further be attached to either or both of the central absorbent member and the outer absorbent member adhesively, by thermal or ultrasonic bonds, or by other attachment means known to one skilled in the art. By geometric considerations alone, a wicking barrier with a ledge can effectively hold the central absorbent member in place between the wicking barrier and the cover when the ledge is attached to the cover or to the surface of the outer absorbent member.
Desirably, the ledge (the horizontal component of the wicking barrier) covers about 30% or more, specifically about 50% or more and most specifically about 80% or more of the body-side surface of the outer absorbent member along the transverse axis of the article, with essentially 100% coverage in the target zone being desirable in many embodiments.
The central absorbent member can be formed from any known absorbent material such as cellulosic fibrous webs and the like. It generally is the primary absorbent component of the article and is at least partially surrounded by an outer absorbent member a width (taken as the total edge-to-edge span in the transverse direction) greater than the width of the central absorbent member.
The outer absorbent member typically serves as a frame or shaping element for the absorbent article, in part by virtue of its ability to remain dry and resilient in use. The outer absorbent member can also serve as a backup absorbent reservoir when the central absorbent member is becoming saturated or threatened with leakage. The outer absorbent member can be both wider and longer than the central absorbent member, and has a central void for receiving at least a portion of the central absorbent member and optionally for receiving the central rising member. In the target zone, folding of the outer absorbent member in use coupled with the upward deflection of the central absorbent member generally results in a W-shaped absorbent article well suited for maintaining good body fit and for absorbing fluids effectively from the body of the wearer.
The central rising member can be operatively associated with the central absorbent member in several ways. The central rising member can be disposed below the central absorbent member, either in direct contact with the central absorbent member or with a wicking barrier or other element disposed therebetween. Alternatively, the central rising member can be a structure embedded within the absorbent material of the absorbent core and specifically within the central absorbent member, capable of upwardly deflecting the central absorbent member or at least the absorbent material in the central absorbent member that lies above the central rising member. Also alternatively, the central rising member itself can be an absorbent component of the central absorbent member or can be the major component of the central absorbent member, forming at least the predominant part of the central absorbent member. Thus, the central rising member can rise toward the body in response to lateral compression and then directly absorb body exudates.
Further improvements in body fit and deformation of the article in use can be achieved by adding additional features to the articles of the present invention. For example, improved deformation can also be promoted or assisted by one or more shaping lines and/or one or more crease lines in the absorbent core. A crease line lies away from the longitudinal centerline and promotes downward folding or bending of the article along the crease line (e.g., a valley fold) during lateral compression from the longitudinal sides of the article. A shaping line resides in the central absorbent member and promotes upward folding or bending (e.g., a mountain fold) during lateral compression from the longitudinal sides of the article. A shaping line coupled with at least two crease lines works to establish a W-fold geometry in the article when laterally compressed, offering good control over the upward deflecti
Bednarz Julie Marie
Chen Fung-jou
DiPalma Joseph
Lindsay Jeffrey Dean
Kidwell Michele
Kimberly--Clark Worldwide, Inc.
Pauley Petersen Kinne & Erickson
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