Surgery – Means and methods for collecting body fluids or waste material – Absorbent pad for external or internal application and...
Patent
1997-06-17
1999-08-24
Clarke, Robert A.
Surgery
Means and methods for collecting body fluids or waste material
Absorbent pad for external or internal application and...
604358, 604374, 6043851, A61F 1315
Patent
active
059418630
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to an absorbent article which includes a liquid-permeable casing sheet disposed on a first article surface, a liquid-impermeable casing sheet disposed on a second article surface, and an absorbent body which is enclosed between the two casing sheets and which includes a receiving space in which body liquid is taken up, said space consisting in at least one cavity or one region of lower density than those parts of the absorbent body which border on the receiving space and which lie generally in the same plane.
Hitherto, the problem encountered with absorbent articles, such as diapers, pants-type diapers, incontinence guards, sanitary napkins or like articles which are intended to repeatedly receive and absorb body liquid, or fluid, discharged by a user is that the rate at which the liquid is able to penetrate into the article decreases considerably with each new wetting occasion. This problem is particularly pronounced in diapers and incontinence guards that are intended for children and adults, since in these cases the quantities of liquid that the article will receive and absorb are relatively large and are discharged within the space of only a few seconds. It is therefore not unusual, particularly after a first wetting of the article, that the liquid which is not immediately released into the article will instead flow over the surface of the article and leak past the edges thereof. Such leakage of body liquid is naturally highly undesirable, since it is liable to soil the clothes, bed linens and mattresses used by the wearer, and even stain and destroy such commodities.
The reason why the body liquid penetration rate decreases with repeated wetting of the article is because the absorbent body of the article becomes saturated with body liquid temporarily within a limited area around the area on the article surface in which the body liquid first impinges, the so-called primary wetting area. The absorbent articles are normally comprised of one or more layers of hydrophilic fibres, for instance cellulose fluff pulp, and often also include a powerful absorbing hydrocolloidal material, so-called superabsorbents. Liquid is transported relatively slowly through such materials, since transportation of the liquid is mainly caused by the capillary forces acting in the cavities located between fibres and particles in the absorbent body of the article. Liquid is transported within the hydrocolloidal materials by diffusion, which is a still slower process than the process generated by the capillary forces. The liquid will therefore remain in the primary wetting area of the article for a relatively long period of time and will then gradually be transported out to surrounding parts of the absorbent body.
The problem has been accentuated in recent years, since development has tended towards absorbent bodies which have been compressed to greater and greater degrees of compression with the intention of reducing packaging volume and for reasons of transportation, storage and environment.
It is known to provide the article with liquid-transporting means in the form of compressed patterns, for instance compressed stripes, which function to disperse the liquid in the longitudinal direction of the article, so as to steer the transportation of liquid away from the primary wetting area to parts of the absorbent body in which absorbent material is still unused. An article possessing such compressed stripes is earlier known from PCT/SE94/00835. Liquid transportation in the article is mainly the result of the differences in capillary forces acting between the compressed stripes and surrounding material. Even though a positive effect is obtained in this case in the form of a directed liquid flow in the absorbent body, the rate at which liquid is transported in the article is much too slow in relation to the rate at which body liquid is discharged to the article. Consequently, there is a risk that the liquid will not be absorbed quickly enough, but instead will run along the surface of the article and out
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Buschka Anette
Guidotti Ted
Gustafsson Anders
Widlund Urban
Clarke Robert A.
Peppers, III Miley Craig
SCA Molnlycke AB
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