Surgery – Means and methods for collecting body fluids or waste material – Absorbent pad for external or internal application and...
Reexamination Certificate
2000-05-12
2002-10-15
Lewis, Aaron J. (Department: 3761)
Surgery
Means and methods for collecting body fluids or waste material
Absorbent pad for external or internal application and...
C604S385101
Reexamination Certificate
active
06465711
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to sanitary absorbent articles such as sanitary napkins, pantiliners and adult incontinence pads. More specifically, it relates to the construction of the body faceable cover layer of such articles.
BACKGROUND OF THE INVENTION
Sanitary absorbent articles are articles of manufacture that generally are used to absorb and retain bodily exudates; they have both medical and non-medical uses. Conventional sanitary absorbent articles generally comprise several different layers of material joined together to form a laminate. Each of these layers is referred to as a “component layer” and serves a specific function within the article. Each layer is thus usually fabricated from a material different than that of the others, and has different physical properties and characteristics.
The uppermost layer of material, i.e. the layer that is intended to face the body of a wearer of the article when the article is in use is conventionally termed the “cover layer” or “top sheet”. The cover layer is generally relatively soft to the touch so as to avoid discomfort and prevent abrasions to the human tissue with which it is in contact during the time which the article is worn. The cover layer is fluid permeable to permit the ingress of bodily exudate into the article to be absorbed and retained. At the same time, however, the cover layer preferably remains dry to prevent moisture from accumulating against the skin of the wearer causing irritation. In order to meet these desired characteristics, conventional cover layers are manufactured from non-woven fibrous materials or polymeric, preferably thermoplastic, films, having a large number of relatively small apertures per unit surface area. Each of these types of materials is well known in the art.
Neither of these materials is, however, without its drawbacks. Non-woven fibrous materials have the characteristic of planar (lateral) wicking. As described above, it is generally desired that bodily exudate to be absorbed by the article pass through the cover layer to the absorbent layer therebelow. As non-woven cover layers comprise fibrous components, however, some bodily exudate will wick in the plane of a cover layer owing to the capillary action of the fibers thereof. Depending on the quantity of exudate impinging upon the cover layer, such bodily exudate will eventually migrate to the sides of the article and will egress the cover layer and soil the garments (or undergarments) of the wearer. In many non-woven cover materials the fibers are generally oriented all in the same direction, usually either parallel to the longitudinal centerline or to the transverse centerline of the article (these axes are well known to those skilled in art and are also defined below). In these covers the majority of lateral wicking occurs in a direction parallel to that of the fiber direction. As the length of the article in a direction parallel to the transverse centerline is shorter than that in a direction parallel to the longitudinal centerline, this problem is therefore much worse when the fibers are oriented parallel to the transverse centerline, particularly in a central region of the article.
In contrast, apertured thermoplastic films do not gene rally wick fluids within the plane of the film, as they do not comprise fibrous elements, nor are they intrinsically absorbent. Thus, substantially no lateral wicking occurs and substantially the entirety of exudate impinging upon cover layers of these materials passes therethrough to the absorbent layer below. The disadvantage of such materials is that they may feel hot and sticky against the skin of a wearer, and may be thus uncomfortable. In addition, the absorbent core directly below the source of body exudate has a greater tendency to become saturated.
One solution to the potential problem of the hot and sticky feel of the apertured thermoplastic film is a sanitary absorbent article having a composite cover layer as described in International Patent Application Publication No. WO 93/09744. The composite cover layer described therein has a central zone extending longitudinally down the center of the article, and end zones extending laterally (transversely) from the central zone. The central zone comprises an apertured thermoplastic film, while the end zones comprise a non-woven material. The stated purpose of such a construction is to position the non-woven material in areas likely to come into contact with the skin of the wearer, while still retaining some of the benefit of having an apertured thermoplastic portion of the cover layer.
A cover layer of such construction suffers from two distinct problems. The first is that the regions of the cover layer which are near the transverse ends of the article also come into contact with the skin of the wearer, yet they still comprise a thermoplastic film. Thus, these portions may still feel hot and sticky to a wearer of the article. The second problem with such a construction is that the end zones (as described therein) still comprise a non-woven material in their marginal portions, thus any body exudate coming into contact therewith risks being wicked to the longitudinal edge of the article and staining the undergarments of the wearer. Moreover, it has been observed that generally, wearers of such articles would prefer to suffer a minor inconvenience in the form a slight hot and sticky feel rather than have the article fail to retain all of the body exudate impinging on it, and having their garments/undergarments soiled by such exudate.
There is therefore still a need in the art to provide a sanitary article having an improved cover layer construction. There is particularly a need to provide a sanitary absorbent article having reduced incidence of side leakage owing to lateral wicking along the cover layer, while reducing the hot and sticky feel associated with prior art articles having cover layers comprising apertured thermoplastic films.
SUMMARY OF THE INVENTION
It is thus an object of the present invention to pro vide a sanitary absorbent article having an improved cover layer construction.
It is another object of the present invention to provide a sanitary absorbent article having reduced incidence of side leakage owing to lateral wicking along the cover layer, while reducing, to some extent, the hot and sticky feel associated with prior art articles having cover layers comprising apertured thermoplastic films.
In accordance with the present invention, there has been provided a sanitary absorbent article adapted to be worn in a crotch portion of wearer's undergarment having a main body portion with two opposing longitudinal sides, two opposing transverse sides, an imaginary longitudinal centerline and an imaginary transverse centerline; the main body comprising:
(A) a fluid-pervious cover layer, the cover layer facing towards a wearer's body when the article is in use by a wearer;
(B) a fluid-impervious barrier layer, the barrier layer facing away from the wearer's body when the article is in use by the wearer;
(C) an absorbent system intermediate the cover layer and the barrier layer; the cover layer having:
(1) an intermediate zone located in a centrial region of the main body and adapted for registration with a source of bodily exudate to be absorbed by the article when the article is in use by the wearer, the intermediate zone including marginal portions adjacent the respective longitudinal sides of the main body and extending towards the longitudinal centerline, the marginal portions comprising a material having a higher degree of vertical liquid migration than lateral liquid migration; and
(2) a first terminal zone adjoining the intermediate zone and extending longitudinally away therefrom toward one of the transverse sides of the main body, the first terminal zone comprising a material having a higher degree of lateral liquid migration than vertical liquid migration.
The sanitary napkin of the present invention may optionally be provided with flexible flaps that project laterally outward from t
Barr James P.
Bogart Michael
Johnson & Johnson Inc.
Lewis Aaron J.
LandOfFree
Absorbent article having an improved cover layer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Absorbent article having an improved cover layer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Absorbent article having an improved cover layer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3000542