MXPA99003053A - Disposable absorbent article having a profiled absorbent structure being capable of self-shaping in use - Google Patents

Abstract

This invention is a disposable absorbent article (20) for wearing adjacent a body discharge area having a longitudinal centerline, and a lateral centerline orthogonal thereto;and defining longitudinal and lateral directions, respectively. The disposable absorbent article (20) comprises a liquid pervious topsheet (24), a backsheet (26) joined to said topsheet (24), and an absorbent core (28) intermediate the backsheet (26) and the topsheet (24). The absorbentcore (28) comprises an expanding layer (46) for expanding the article (20) into a tridimensional structure while being worn by a user. The expanding layer (46) is activated by body fluids, and has a predetermined profile in Z direction in the dry state prior to use. The expanding layer (46) is capable, upon activation by body fluids, of expanding into the predetermined wet profile.

Description

ABSORBENT DISPOSABLE ARTICLE THAT HAS A PROFILE ABSORBENT STRUCTURE THAT IS ABLE TO BE ABLE TO CONFORM IN USE FIELD OF THE INVENTION The present invention relates to disposable absorbent articles. Disposable absorbent articles are considered to be absorbent devices designed to be used externally to a user's body, and to receive discharged fluids from the body. In particular, the present invention relates to sanitary napkins, catamenial products, incontinence inserts, pantiliners and disposable absorbent diapers comprising an expansion layer for expanding the article into a three-dimensional structure while being worn by a wearer. The expansion layer is activated by bodily fluids and provides the article with a self-training capability during use. The expansion layer further has a predetermined profile in the Z direction before being used, and is capable of expanding to a predetermined wet profile upon activation by body fluids.

BACKGROUND OF THE INVENTION In its basic form, the disposable absorbent articles comprise an absorbent core interposed between a permeable element that contacts the body (alternatively referred to as a topsheet or overwrap) and a protective waterproof barrier (alternatively referred to as a backsheet). The absorbent element is, of course, intended to receive and contain the discharged fluids from the body. The element that contacts the body is intended to provide a comfortable and dry feeling contact with the body surfaces, while allowing free passage of fluids therethrough to the absorbent element. The protective barrier is intended to prevent the fluids that are expelled or escaping from the absorbent element from soiling the users' garments. In addition to the three functional elements mentioned above, the disposable absorbent articles are generally provided with means for supporting the device adjacent to the crotch area of the user, even when the user moves, where they can effectively perform their intended function. Typically, absorbent articles such as sanitary napkins are provided with an adhesive attachment means to secure the device to the inner crotch area of the wearer's undergarments. An improvement in the comfort and convenience of these absorbent articles has been in the development of the absorbent articles that achieve a better fluid intersection by means of a closer contact of the absorbent article by itself with the wearer's body. Although the previously known absorbent articles perform their intended function, each conventional design can be further improved by one or more of the absorption of body fluids, protection against staining of the wearer's garments, physical comfort of the wearer, and / or the ability to provide an anatomically shaped configuration for contact with the narrowest body. With respect to disposable sanitary napkins, many attempts have been made in the art to improve body contact with the user, and thereby absorb fluids upon discharge and thus reduce soiling by providing a sanitary napkin having a configuration anatomically formed, particularly including those that rise up or form a hump in their middle parts to be near or in contact with the pudendal region when used.

In female users this type of sanitary napkins try contact and absorb menstruation immediately that they leave the vestibule. Some articles have also been described in which an anatomically shaped configuration is provided during the time of use, with the advantage of a better fit to the anatomy. United States Patent No. 3No. 736,931 discloses a sanitary napkin having an uncompressed outer layer of fluid absorbent material and an inner core of highly compressed fluid absorbent material which is at least partially enclosed therein! The sanitary napkin is preferably V-shaped in cross section and is arcuate in its longitudinal direction by compression in the mold. When the towel is used, the fluid is first directed towards the inner compressed layer to cause it to swell and expand in all directions to the non-compressed outer layer, thus self-adjusting each user. The sanitary pad expands when absorbing fluids and can self-adjust to the user's anatomy, but because it is not flat before use it can be difficult to pack and manipulate; moreover, the expansion takes place mainly in the lateral direction, thus achieving an effective seal against the outer side of the thighs and both sides of the vaginal orifice; therefore, the structure is not able to achieve close contact with the anatomy of the wearer, particularly in that it does not put the absorbent element in direct contact with the point of fluid release. According to U.S. Patent No. 3,512,530, a sanitary napkin is described in which a compressed regenerated cellulose sponge layer is combined with a larger layer of fiber cellulose to form a multi-layer absorbent core. The regenerated, compressed cellulose sponge layer is placed on the fibrous layer, and is typically centered around it; this is intended as the primary absorbent member of the sanitary napkin, while the fibrous layer acts as a secondary or backup absorber. Therefore, the sanitary napkin can be very thin before being used, as compared to other sanitary products having the same absorbent capacity. Although the regenerated, compressed cellulose sponge layer is capable of expanding in the Z direction upon absorbing the fluid, the structure described is not particularly suited to provide effective body contact with the wearer's anatomy and could cause discomfort to the wearer , due to the characteristics of the regenerated, compressed cellulose sponge material, particularly when it is dry. European patent EP 293 208 B1 discloses the use of multiple layers of regenerated, compressed cellulose sponge sheets in a sanitary napkin as the sole absorbent material instead of the absorbent core of normal cellulose pulp, in order to obtain an article Absorbent strength and shape retention capacity improved in wet conditions, as compared to traditional absorbent articles with lint cores that tend to break or lump during use. The sheets are provided with slits in order to increase their flexibility, with better comfort for the wearer, and to increase the fluid absorbing area. The sanitary napkin described in European Patent EP 293 208 B1 has a structure that is not specifically intended to provide a self-forming capability during use, taking advantage of the swelling of the absorbent material, but instead a better resistance when it is wetted than articles using conventional, fluff-based absorbent cores, and improved flexibility and absorbency rate as compared to articles using the same regenerated cellulose compressed sponge material.

In the European patent application EP 96106721.2 filed on April 29, 1996, absorbent articles comprising means for expanding the article into a three-dimensional structure while being used by the user are described. The media is activated by body fluids and comprises a compressed sponge sheet of regenerated cellulose. The absorbent articles described in the aforementioned application are capable of providing an anatomically shaped configuration for close body contact, which is achieved during use by activating media absorbed body fluids, and is comfortable for the wearer and easy to produce and pack. Their performance can be improved in terms of a better ability to conform to the user's anatomy. It is therefore an object of the present invention to provide an absorbent article that is capable of providing a closer body contact that is achieved during use, by being activated by the absorbed bodily fluids while being comfortable for the user, easy to produce and to pack, and able to achieve easily and very quickly upon activation by bodily fluids of anatomically shaped yet complex configurations. It is a further object of the present invention to provide an absorbent article that a better ability to achieve closer body contact during use, even the period of time before activation by body fluids while still substantially flat and thin before use.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to disposable absorbent articles for use adjacent to a body discharge area, which are substantially planar before being used. The disposable, substantially planar absorbent article a longitudinal center line and a lateral center line orthogonal thereto which defines the longitudinal and lateral directions respectively, and a Z direction that is orthogonal to both of these. The disposable absorbent article comprises a liquid pervious top sheet, a back sheet, preferably liquid impervious, bonded to said top sheet, and an intermediate absorbent core between the top sheet and the back sheet. The term "substantially flat", as used herein, refers to articles that have their principal extension in the X-Y plane. The absorbent core comprises an expansion layer for expanding the article into a three-dimensional structure while being used by a user, wherein the expansion layer is activated by the body fluids. The expansion layer a predetermined profile in the Z direction in the dry state before being used, and is capable of expanding, upon full activation by body fluids, towards a predetermined wet profile.

BRIEF DESCRIPTION OF THE DRAWINGS Although the description concludes with the claims singling out and claiming in a different manner from the present invention, it is believed that the present invention will be better understood from the following description in combination with the following drawings: Figure 1 is a view in top plant of a sanitary napkin embodiment according to the present invention; Figure 2 is a cross-sectional view of the sanitary napkin shown in Figure 1, as taken along a section line corresponding to the transverse center line A-A; Figure 3 is a cross-sectional view similar to that of Figure 2, showing the sanitary towel expanded into a three-dimensional structure after activation during use; Figures 4a and 4b are a cross-sectional view taken along the transverse center line A-A of the expansion layer, showing alternating modes of the predetermined profile; Figure 5 is a cross-sectional view of another embodiment of a sanitary napkin according to the present invention; Figure 5 is a cross-sectional view similar to that of Figure 2, showing the sanitary towel expanded into a three-dimensional structure after activation during use.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disposable absorbent article that exhibits absorbency to body fluids, protection of users' garments against staining, improves the user's physical comfort, which is easy to produce and pack. The disposable absorbent article is described below with reference to a sanitary napkin or a catamenial product. The term "sanitary towel", as used herein, refers to an article that is worn by women, adjacent to the pudendal region and that is intended to absorb and contain various bodily fluids that are discharged from the body (eg. example, vaginal discharge, menstruation and / or urine) and which is intended to be discarded after a single use. The disposable absorbent article is preferably substantially planar before being used.

The term "substantially planar", as used herein, refers to articles that have their principal extension in a plane. In a preferred embodiment, a substantially flat article will have an absorbent core extending substantially in the XY directions, with the dimension extending in the Z direction being substantially smaller than the two other dimensions extending in the X and Y directions, respectively. This comprises an absorbent core having a thickness that is not constant or, in other words, that is not formed in a direction that is orthogonal to the absorbent core itself, provided that the above condition is satisfied. This does not exclude a general curvature of the absorbent core. It will be apparent to a person with ordinary skill in the art to whose range of products they can deviate in an absolutely flat manner and still benefit from use training in accordance with the present invention. Sanitary napkins with longitudinal side bends, which may be optionally elasticized, and sanitary napkins with a moderate curvature, therefore are within the scope of the present invention, and their absorbent core may preferably be substantially planar, in accordance with the definition given above. The term "predetermined profile", as used herein, refers to an expansion layer comprising zones that, upon full activation by body fluids, are capable of expanding more than other zones according to a real profile , desired, which substantially corresponds to the predetermined profile of the expansion layer in its dry state. The profile achieved by the expansion layer after expansion upon activation by the body fluid is the "predetermined wet profile" referred to herein. The term "predetermined profile", therefore, is not associated in its context with a contour of the particular, actual expansion layer, when viewed in the cross section in its dry state before being activated by bodily fluids.

The term "use", as used herein, refers to the period of time that begins when the absorbent article is actually placed in contact with the user's anatomy. The terms "attached" or "fixed", as used herein, encompass configurations with which a first member is directly connected to a second member and configurations with which a first member is indirectly connected to a second member by connecting the first member to intermediate members, who in turn are connected to the second member. The interlabial devices that reside partially within and partially outside the wearer's vestibule are also within the scope of the present invention.

As used herein, the term "Pudendo" refers to the externally visible female genital organs and is not limited to the labia majora, labia minora, clitoris and the vestibule. In Figures 1 and 2, a preferred embodiment of a sanitary napkin 20 of the present invention is shown. Figure 1 is a plan view of the sanitary napkin 20 of the present invention in its flattened state before being used, with portions cut away from the structure to more clearly show the construction of the sanitary napkin 20 and with the portion of the sanitary napkin 20 facing towards or contacting the user facing the viewer. As shown in Figures 1 and 2, the sanitary napkin 20 preferably comprises a liquid-permeable upper sheet 24, a liquid-impermeable back sheet 26 attached to the upper sheet 24, and an intermediate absorbent core 28 to the upper sheet 24 and the back sheet 26; the absorbent core 28 comprises an expansion layer 46 for expanding the sanitary napkin in a three-dimensional structure while being worn by a wearer. In a preferred embodiment of the present invention illustrated in Figures 1 to 3, the absorbent core 28 comprises the expansion layer 46 and a separate, substantially unexpanded absorbent member 44, joined together and in facing relation to one another, the expansion layer 46 positioned between the topsheet 24 and the absorbent element 44. The element 44 and the expansion layer 46 may be associated in any suitable manner to form the absorbent core 28. Suitable manners include, but are not limited to, associating the absorbent core 44 and the expansion layer 46 with adhesives such as spray-bonding or by applying lines or dots of adhesives therebetween. Alternatively, or additionally, the association between the layers can be achieved by entangling the fibers or by a plurality of discrete melt bonds. Alternatively, the expansion layer 46 may constitute the entire absorbent core 28. The absorbent capacity of the absorbent core 28 must be compatible with the intended load of body fluid for the sanitary napkin 20. In addition, the total absorbent capacity of the absorbent core 28 can be varied to fit users who vary in the expected amount of body fluid volume. For example, a different absorbent capacity may be used for sanitary napkins attempted for daytime use as compared to those intended for night use, or for sanitary napkins intended for use by adolescent women as compared to those intended for mature women . The sanitary napkin 20 has two surfaces, a surface that faces towards or makes contact with the body, a surface that faces towards or makes contact with the garment. The absorbent core 28 has surfaces facing the body and corresponding to the garment. The sanitary napkin 20 has two central lines, a longitudinal central line O-O and a transverse central line A-A orthogonal thereto. The term "Longitudinal", as used herein, refers to a line, axis or direction in the plane of the sanitary napkin 20 that is generally aligned with (eg, approximately parallel to) a vertical plane that divides a user from foot in left and right body halves when using sanitary napkin 20. The terms "Transversal" or "Lateral" as used herein, are interchangeable, and refer to a line, axis or direction that is located within the plane of the sanitary towel 20 and is generally perpendicular to the longitudinal direction. The Z-direction is orthogonal to both longitudinal and lateral directions of the sanitary napkin 20 and extends outwardly from the plane of the sanitary napkin 20, which is defined by the longitudinal centerline O-O and the lateral centerline A-A. The term "Longitudinally oriented" refers to a direction of ± 45 degrees of the longitudinal direction in the plane of the sanitary napkin 20; the term "Laterally oriented" refers similarly to any other direction in the plane of the sanitary napkin 20. The long edges of the sanitary napkin 20, which are aligned with the longitudinal centerline OO, are the longitudinal side margins of the sanitary napkin. the sanitary napkin 20. The ends of the sanitary napkins 20 joining the longitudinal side margins are the transverse ends of the sanitary napkin 20. Collectively, the longitudinal lateral margins and the transverse ends of the sanitary napkin 20 define their periphery. Similarly, the absorbent core 28 of the sanitary napkin 20 has a periphery defined by the longitudinal side margins and the transverse ends arranged alternately. The three-dimensional structures of the sanitary napkin 20 are those in which the structure of the sanitary napkin is made to expand, at least partially, in the Z direction, in order to conform more closely to the anatomy of the wearer. Said expansion preferably takes place in a direction that goes from the garment surface to the surface facing the body of the sanitary napkin 20.

Particularly preferred are three-dimensional structures with an upwardly convex configuration that are inclusive of, but not limited to, inverted U shapes or inverted V shapes, with "Convex configuration upward" which is intended for a structure of the sanitary napkin that It is convex on its surface that faces the body. With these configurations the cross-sectional contour of the central portion of the sanitary napkin more closely matches the lips of typical users. Alternatively, the preferred three-dimensional structures of the sanitary napkin 20 are W-shaped or inverted W-shapes as seen in the lateral direction. The topsheet 24 is docile, of soft feel and non-irritating to the wearer's skin. In addition, the topsheet 24 is permeable to liquid, allowing liquids to easily penetrate through its thickness. A suitable top 24 can be manufactured from a wide range of materials, such as woven and non-woven materials; polymeric materials such as thermoplastic films formed with openings, plastic films with openings, and hydroformed thermoplastic films; porous foams; cross-linked foams; crosslinked thermoplastic films; and thermoplastic canvases. Suitable woven and nonwoven materials may be composed of natural fibers (eg, wood or cotton fibers), synthetic fibers (eg, polymeric fibers such as polyester, polypropylene or polyethene fibers); or from a combination of natural fibers and synthetic fibers. A preferred top sheet comprises a film formed with openings.

Films formed with openings are preferred for the topsheet because they are permeable to body fluids and not yet absorbent, and have a reduced tendency to allow liquids to pass back through and rewet the skin of the wearer. In this way, the surface of the formed film that is in contact with the body remains dry, thus reducing the soiling of the body and creating a more comfortable feeling for the wearer. Suitable formed films are described in U.S. Patent No. 3,929,135, issued to Thompson on December 30, 1975; U.S. Patent No. 4,324,246, issued to Mullane, others on April 13, 1982; U.S. Patent No. 4,342,314, issued to Rael, et al., August 3, 1982; U.S. Patent No. 4,463,045, issued to Ahr, and others on July 31, 1984; and U.S. Patent No. 5,006,394, issued to Baird on April 9, 1991. A preferred top sheet for sanitary napkin 20 of the present invention is a formed film described in one or more of the above patents and sold in sanitary napkins by The Procter & Gamble Company of Cincinnati, Ohio as "DRI-WEAVE". In a preferred embodiment of the present invention, the exposed body surface or surface of the formed top sheet of film is hydrophilic to help transfer liquid through the top sheet faster than if the body surface were not hydrophilic, for decrease the likelihood that menstrual fluid will flow out of the upper sheet instead of flowing into and being absorbed by the absorbent core. The topsheet of the present invention is preferably capable of expanding as the sanitary napkin 20 expands into a three-dimensional structure upon absorption of the body fluids. This can be achieved when making the topsheet of a material that is intrinsically extensible under the forces exerted by the expansion layer 46. In a preferred embodiment illustrated in Figures 1 and 2, the topsheet 24 is provided with two plies or folds 52 located symmetrically on both sides of the longitudinal center line OO and substantially parallel thereto. As shown in Figure 2, the topsheet 24 in each fold or fold 52 is bent twice on itself towards the longitudinal side margins of the sanitary napkin 20. A single fold or fold, or alternatively, more than two folds may also be comprised in the topsheet 24 without departing from the scope of the present invention; the folds or bends may be generally oriented longitudinally or laterally. The backsheet 26 is impermeable to liquid (eg, menstruation and / or urine) and is preferably manufactured from a thin plastic film, although other flexible liquid impervious materials may also be used. In use, the backsheet 26 is interposed between the absorbent core 28 and the wearer's undergarments. The function of the backsheet 26 is to prevent the exudates, which can be expelled from or inadvertently diverting the absorbent core 28, from contacting and soiling the wearer's undergarments. The backsheet 26 can, thus, comprise a woven or non-woven material, polymeric films such as polyethylene or polypropylene thermoplastic films, or composite materials such as a film-coated nonwoven material. Preferably, the backsheet is a polyethylene film having a thickness of about 0.012 mm to about 0.015 mm. The backsheet 26 is preferably embossed and / or dull finished to provide a more fabric-like appearance. In addition, the backsheet can allow vapors to escape from the absorbent element 26 (ie, breathable), while still preventing the exudates from passing through the backsheet. In a preferred embodiment of the present invention, the sanitary napkin 20 is also provided with a panty fastening means, not shown in the figures for clarity, which provides the means for securing the article to an undergarment. For example, the fastening means of the panty may comprise a mechanical fastener, such as hook and loop fasteners, such as sold under the trade name VELCRO, fasteners or fasteners. Alternately, the sanitary napkin 20 is attached to the undergarment by means of the panty fastening adhesive coated on the garment facing surface of the backsheet 26. The panty fastening adhesive provides a means to secure to the sanitary napkin 20 to the panty, and preferably a means to secure the sanitary napkin 20 when the package folded and wrapped is soiled for convenient disposal. Typically, at least a portion of the garment facing surface of the backsheet 26 is coated with the adhesive to form the panty fastening adhesive. Any adhesive or glue used in the art for this purpose can be used for the fastening adhesive of the pantyhose herein. Pressure sensitive adhesives are more preferred. Suitable adhesives include Century A-305-IV manufactured by Century Adhesives Corporation of Columbus, Ohio, Instant LOK 34-2823, manufactured by National Starch and Chemical Company of Bridgewater, New Jersey, 3 Sigma 3153 manufactured by 3 Sigma and Fuller H- 2238ZP manufactured by HB Fuller Co. The panty fastening adhesive is typically applied to the backsheet 26 by slot coating or spraying in various distribution patterns such as, for example, discontinuous and discontinuous strips, intermittent dots, random spiral patterns. The panty fastening adhesive is typically covered with a removable release paper or film in order to prevent the adhesive from drying or adhering to a different surface of the panty before being used. Any commercially available release paper or film can be used. Suitable examples include BL 30 MG-A SILOX El / O and BL 30 MG-A SILOX 4 P / O available from Akrosil Corporation. If present, as illustrated in Figures 1 to 3, the substantially unexpanded absorbent member 44 of the absorbent core 28 may comprise any absorbent means that is generally compressible, elastic, non-irritating to the wearer's skin and capable of absorbing and contain body fluids The absorbent member 44 can be manufactured from a wide variety of liquid absorbent materials commonly used in disposable sanitary napkins, and other disposable absorbent articles. Examples of suitable absorbent materials include ground wood pulp (which is generally referred to as air filters), creped cellulose wadding, modified crosslinked cellulose fibers (such as those described in U.S. Patent No. 4,217,445 issued to Young, et al. On June 8, 1993), capillary channel fibers (i.e., fibers having intrafiber capillary channels such as those described in U.S. Patent No. 5,200,248 issued to Thompson, and others on April 6 of 1993), absorbent foams (such as those described in U.S. Patent No. 5,260,345, issued to DesMarais, and others on November 9, 1993, and in U.S. Patent No. 5,268,244 issued to DesMarais, and others on December 7, 1993 (P &G Case 5051)), thermally bonded air-laid materials (such as those materials described in U.S. Patent Application Serial No. 0) 8/141, 156, entitled "Catamenial absorbent structures having thermally bonded layers for improved management of menstrual fluids and their use in catamenial pads that have improved fit and comfort" presented on behalf of Richards, et al. On October 21, 1993), absorbent sponges, synthetic short fibers, polymeric fibers, hydrogel forming gelling agents, moss peat, or any of the equivalent materials or combinations of materials. Suitable absorbent cores comprising foams are described in European patent applications 0,598,833, 0,598,823 and 0,598,834. In the embodiment illustrated in FIGS. 1 to 3, the substantially unexpanded absorbent member 44 of the absorbent core 28 comprises an absorbent layer 30 made of a thermally bonded longitudinally bent double air-comprising material comprising particles 32 of absorbent material. gelation among these.

As shown in Figures 1 and 2, the absorbent core 28 comprises an expansion layer 46 having a predetermined profile in the Z direction in the dry state before being used to expand the sanitary napkin 20 towards the desired three-dimensional structure while use the sanitary napkin 20. In a manner illustrated in Figures 1 to 3, the expansion and final shape of the sanitary napkin 20 towards the three-dimensional structure is provided by the swelling, substantially in the Z direction, and towards a predetermined profile in wet, of the material constituting the expansion layer 46 and which is activated during use by the absorption of bodily fluids. The expansion layer 46 may comprise any material that is capable of swelling so as to form the sanitary napkin 20 in the desired three-dimensional structure. After absorption of body fluids and subsequent swelling in the predetermined wet profile, the material of the expansion layer 46 should be soft, compliant, conformable and elastic. This must be compressible in such a way that it deforms under the relatively small forces that are experienced during normal use. In addition to being compressible, the material of the expansion layer 46 must be flexible and conformable after inflating, such that it can provide improved fit through the topsheet 24 towards and around the user's perineal lips, when the three-dimensional structure is formed during the time of use. The ability to follow the topography of the anatomy will provide intimate contact with the exposed genitals of the female user. This helps to provide the best fluid transfer from the user to the expansion layer 46. Although these characteristics of the expansion layer 46 allow for improved fit, they also cause the product to be both soft and comfortable for the wearer. It is preferred that the expansion layer 46 forms at least part of the surface facing the body of the absorbent core 28. In the embodiment illustrated in FIGS. 1 and 2, the expansion layer 46 is placed on the absorbent member 44. , in a face-to-face relationship with this; it is rectangular and preferably narrower and shorter than the element 44, as illustrated in Figure 1, being centered around both of the longitudinal and transverse lines O-O and A-A. As an alternative, different shapes of the expansion layer 46 are also possible, for example, an hourglass shape. The expansion layer 46 of the absorbent core 28 has a body facing surface and a garment facing surface, and has a predetermined profile in the Z direction in the dry state before use. The predetermined profile of the expansion layer 46 can be formed by any of the surface facing the body or by the garment facing surface of the expansion layer 46, or by both of them; in other words, any of the surfaces facing the expansion layer can be profiled, that is, not parallel or flat to each other. Preferably, the predetermined profile is formed only by the surface facing the body of the expansion layer 46. The predetermined profile in the expansion layer 46 is preferably provided by varying the cuff of the expansion layer 46; the thickness of the expansion layer 46 may vary in any of the lateral direction, as illustrated in Figures 2, 4a, 4b and 5, or in the longitudinal direction or both. When expansion of the expansion layer 46 takes place in the predetermined wet profile, during the use of the sanitary napkin 20, substantially in the Z direction and upon activation by the absorbed body fluids, this substantially occurs in accordance with the the predetermined profile of the expansion layer 46, that is, the thicker zones of the expansion layer 46 will tend to swell in the Z direction more than the thinner zones, after the total, uniform activation of the expansion layer by the bodily fluids, that is, after the expansion layer 46 has been fully activated by the absorbed body fluids. Therefore, the thickness of the expansion layer 46 is not constant over the entire total surface of the expansion layer 46 itself before being used, but varies to create the predetermined profile. The default profile must be such that the expansion layer 46 upon activation by absorption of bodily fluids during the time of use, expand substantially in the Z-direction towards the predetermined wet profile in order to form the sanitary napkin 20 in a three-dimensional structure that more closely conforms to the anatomy of the user. By carefully selecting the predetermined profile for the expansion layer 46, it is possible to have an expanded structure for the sanitary napkin 20 that is not only capable of achieving a closer shaping capacity to the wearer's anatomy, but can also provide a Faster reaction to activation, by the first, or possibly, small amount of body fluid that is absorbed. This can be explained, since, in addition to the self-forming capabilities of the material itself constituting the expansion layer 46, swelling of the expansion layer 46 can occur according to a profile that already exists in the structure of the layer expansion 46. Moreover, the expansion layer 46 with the predetermined profile may show a better ability to form, when activated by body fluids, three-dimensional structures that conform to the more complex body, for example, those that have both a convex configuration and concave upward, such as the W-forms or the inverted W-shapes as seen in the lateral direction. Preferably, the expansion layer 46 also provides the sanitary napkin 20 of the present invention with an improved ability to conform to the anatomy of the wearer during use and prior to activation by the body fluids, recognizing that this predetermined profile exists in the expansion layer 46 even before any swelling takes place, and which can provide a narrower body contact, while the sanitary napkin 20 is preferably substantially flat before being used and thin at least until activation by the body fluids . The preferred predetermined profiles of the expansion layer 46 are those which cause the expansion layer 46, when activated by bodily fluids, to expand in the predetermined wet profile itself in order to conform more closely to the anatomy of the wearer. The suitable predetermined profiles for the expansion layer 46 are those illustrated in Figures 2 and 5, in which the expansion layer 46 has a predetermined profile, as seen in the lateral direction, such that the expansion layer is thicker along the longitudinal axis OO, and is thinner in its longitudinal lateral margins; this type of predetermined profile provides the article during use, upon full activation by the bodily fluids, and at a lower limit, even before activation, with a configuration substantially convex upward. Other alternate predetermined profiles can be those illustrated in Figures 4a and 4b, which are capable of providing, when activated by body fluids, W-shaped profiles and inverted W-shaped respectively, as seen in the lateral direction . Particularly, the expansion layer 46 shown in Figure 4a can expand when activated by body fluids, in a predetermined wet profile that provides a sanitary article with a type of longitudinal barriers that can be beneficial for the prevention of side runoff. The predetermined profiles for an expansion layer 46, as seen in the lateral direction, need not be constant along the longitudinal center line O-O; these can therefore vary along the longitudinal center line O-O in order to be more equal to the user's anatomy which typically varies from the front portion of the pudendal region, back towards the perineum and towards the buttocks. The expansion layer 46 can be provided with the predetermined profile by means of any known method. Thus, the expansion layer 46 can be constituted by a single layer that characterizes the desired predetermined profile, achieved by, for example, cutting a thicker layer, or by molding one according to the preferred profile. Alternatively, the expansion layer 46 may comprise thinner multiple layers having different shapes and different dimensions, superimposed and joined together in order to form an expansion layer 46 with the desired profile. The expansion layer 46 preferably has a uniform density, even though different densities may be provided in different areas of the expansion layer 46. The behavior of a sanitary towel 20 comprising an expansion layer 46 with a predetermined profile is shown in FIGS. Figures 2 and 3, in which the sanitary napkin 20 is illustrated before and after the expansion of the expansion layer 46, respectively. Figure 2 shows the sanitary napkin 20 before the first fluid absorption, with the expansion layer 46 having its predetermined profile before inflating. Figure 3 shows the sanitary napkin 20 expanded in a three-dimensional structure after activating the expansion layer 46 upon the occurrence of absorption of a first quantity of body fluid received approximately in the center of the expansion layer 46. The first release of fluid is quickly captured within the expansion layer 46 and made to swell in the Z direction, its thickness increased, as can be seen in Figure 3, in the predetermined wet profile. In the preferred embodiment illustrated in Figure 3, the topsheet 24 follows swelling of the expansion layer 46 by unraveling the folds or bends 52, therefore, without limiting swelling. The swelling of the expansion layer 46 upon activation by the body fluids and in accordance with the predetermined profile gives the sanitary napkin 20 an increased capacity to quickly and effectively conform to the anatomy of the wearer. As an alternative embodiment, the expansion layer 46 with the predetermined profile may further comprise, in at least its surface facing the body or its surface facing the garment, incisions as described in European patent application EP 96106724.6 , or openings as described in the European patent application EP 96106723.8, or any combination thereof, as for example described in the European patent application EP 06110576.6, all applications having the same priority date of April 29, 1996. According to additional alternative embodiments, the expansion layer 46 with the predetermined profile may comprise a number of minor elements that are decoupled from each other and that are also coplanar, as described in the European patent application EP 96110576.4, or a number of minor expansion elements decoupled from each other and each being capable of substantially expanding in only one direction As described in the European patent application EP 96110572.3 both applications filed on July 1, 1996. In a preferred embodiment of the present invention, the expansion layer 46 comprises a compressed sponge sheet of regenerated cellulose. The regenerated cellulose sponge which preferably constitutes the expansion layer 46 is a material that is known in the art; Examples of suitable materials are described in U.S. Patent No. 3,954,493, in French Patent Application FR-A-2,203,827, and in European Patent No. EP-B-0,293,208. The regenerated cellulose sponge is a sponge made of a material that contains a cellulose frame. Examples of these sponges include, in addition to sponges consisting of cellulose itself, sponges consisting of a cellulose derivative such as viscose, a cellulose ether and a cellulose ester, and sponges consisting of mixtures of those materials. By way of example only, a regenerated cellulose sponge can be prepared from a mixture of a viscose solution with reinforcing fibers and a porogenic compound, for example, sodium sulfate decahydrate crystals or another alkali metal salt with a high content of crystallized water, the final pore dimension being related to that of the salt crystals. The viscose solution can be extruded through an extrusion die of a desired section, then allowed to coagulate. The material is washed with water after regeneration in order to remove the salt and other possible soluble compounds, then it is dried and, if necessary, compressed to the desired density. The compressed regenerated cellulose sponge has a network structure containing air bubbles created by the removal of sodium sulfate crystals. The compressed sponge material of regenerated cellulose is available in various forms, for example, in layers or sheets of different densities, thicknesses and different base weights; Dry density values for the compressed material used in the present invention are from 0.1 g / cm3 to 1 g / cm3, while the thickness can range from 0.2 millimeters to 5 millimeters. The swelling upon occurrence of liquid absorption of the compressed regenerated cellulose sponge material forming the expansion layer 46, creates a hollow volume that does not crush under wet conditions and therefore allows the material to rapidly acquire additional fluid discharges and transmits them towards the underlying absorbent element 44 of the absorbent core 28. In the embodiment illustrated in Figures 1 to 3, the total absorbent capacity of the sanitary napkin 20 is provided by an absorbent core 28 comprising an expansion layer 46 made of a compressed regenerated cellulose sponge sheet having a predetermined profile in its dry state before use, and a substantially unexpanded absorbent element 44. In a preferred embodiment of the present invention, which is illustrated in FIGS. 1 and 2, the absorbent core 28 comprises an expansion layer 46 constituted by a compressed sponge sheet of regenerated cellulose with a dry density of 0.5 g / cm3; the expansion layer comprises in its dry state before a predetermined profile is used along a direction that is parallel to the transverse center line A-A, while having no such profile in the direction parallel to the longitudinal centerline O-O. Accordingly, the expansion layer 46 has a maximum thickness of 3 mm along its longitudinal center line O-O, which decreases towards both longitudinal side margins where a thickness of 1 mm is reached. The expansion layer 45 is positioned above the absorbent core 28 in a face-to-face relationship with it. The absorbent layer 30 is 207 millimeters long and 64 millimeters wide, and the sheet 46 of the compressed regenerated cellulose sponge is 125 millimeters long and 30 millimeters wide, which is centered around both the longitudinal and longitudinal center lines. transverse OO and AA of the sanitary napkin 20. The sheets of compressed sponge of suitable regenerated cellulose can be those produced by Spontex of France. The compressed sponge sheet of regenerated cellulose which preferably constitutes the expansion layer 46 is capable of rapidly absorbing bodily fluids with a large increase in its volume, generally from about 2 to 20 times, and usually from 5 to 15 times its volume in the moment of compression.

The increase in volume substantially corresponds to a swelling in the direction of compression, which is in the Z direction of the sanitary napkin 20, towards the predetermined wet profile of the expansion layer 46. The sanitary napkin 20 is produced and packaged as a conventional flat product, as illustrated in Figures 1 and 2. After the sanitary napkin has been used, as soon as the absorbed body fluids come into contact with the expansion layer 46, it will begin to swell in the direction Z increasing its thickness in the predetermined profile, as can be seen in figure 3; the swelling is more pronounced along the longitudinal central line O-O of the sanitary napkin 20, in order to conform more closely to the anatomy of the wearer, namely to the groove between the labia majora. The topsheet 24 follows swelling of the expansion layer 46 by unraveling the folds or bends 52, thereby increasing its width without limiting swelling. The swelling of the compressed sponge sheet of regenerated cellulose constituting the expansion layer 46 takes place only on activation by the absorbed fluid, which is only during the use of the sanitary napkin 20 and in close contact with the user's anatomy.; the formation of the three-dimensional structure can therefore achieve a much better fit with the anatomy of the wearer, in combination with the preferential swelling in the predetermined wet profile in the expansion layer 46. Moreover, the swelling of the sheet compressed regenerated cellulose sponge 46 can start where it is actually reached by the first fluid, for example at different positions along the longitudinal center line OO; The formation of the three-dimensional structure can therefore also adjust the different possible ways in which bodily fluids can be released by several users. The expanding top sheet 24 also provides comfortable contact with the wearer's anatomy, without limiting the expansion of the sanitary napkin 20 into the desired three-dimensional structure upon activation by body fluids. The sanitary napkin of the present invention is preferably substantially flat before use, and can therefore be manufactured and packaged more easily than a conventional elastified or preformed article. Since the three-dimensional structure is formed only during use, the sanitary napkin of the present invention is also easy to use. The predetermined profile of the expansion layer 46 does not affect these characteristics of the sanitary napkin 20, and may in fact increase the self-shaping capacity of the sanitary napkin 20 during use, within the period of time before activation by the bodily fluids and the subsequent swelling of the expansion layer 46. The expansion layer 46 for expanding the sanitary napkin 20 in the three-dimensional structure during use may be comprised in the sanitary napkin 20 in any other suitable position and / or orientation in order to to achieve the desired three-dimensional structure, in particular, the expansion element 46 can form at least part of the garment facing surface of the absorbent core 28. As often as desired, any component of the absorbent article 20 can comprising a single layer or, alternatively, multiple layers joined or fixed together to form the component itself. In an alternate embodiment of the present invention, the sanitary napkin 20 may have two fins (not shown), each of which are adjacent to and extend laterally from the lateral edge of the absorbent core. The fins are configured to drape over the edges of the wearer's panties in the crotch region, such that the fins are disposed between the edges of the wearer's panties and the thighs of the wearer. The fins serve at least two purposes. First, the fins help to avoid soiling the user's body and their panties by the menstrual fluid, preferably forming a double-walled barrier along the edges of the panty. Second, the fins are preferably provided with fastening means on the garment facing surface such that the fins can be folded back under the panty and attached to the panting side of the panty. In this way, the flaps serve to keep the sanitary napkin properly placed in the pantyhose. The fins can be constructed of various materials including materials used for the topsheet 24, the backsheet 26, combinations thereof, and can be a laminate having tissue in the center. In addition, the flaps may be a separate element attached to the main body of the sanitary napkin 20 or may comprise extensions of the upper sheet 24 and / or the backsheet 26. However, it is recommended that the flaps have a backsheet impervious to liquid to prevent the bodily fluids reaching the fins from contaminating the edges of the wearer's panties. Preferred fins that are suitable or adaptable to the sanitary napkin 20 of the present invention are disclosed in U.S. Patent No. 4,687,478 issued to Van Tilburg on August 18, 1987; U.S. Patent No. 4,589,876 issued to Van Tilburg on May 20, 1986; and U.S. Patent No. 4,608,047 issued to Mattingly on August 26, 1986. Optionally, the sanitary napkin 20 may comprise components that naturally wrap the sides of a wearer's panties. Sanitary napkins having components that naturally surround the sides of the panties suitable for use with the sanitary napkin 20 of the present invention are disclosed in U.S. Patent Application Serial No. 08 / 096,121 entitled "Absorbent Article which has panty cover components that naturally surround the sides of the pantyhose ", filed July 22, 1993, in the name of Lavash, and others and the United States patent application serial number 08/277733 entitled" Articles absorbers that have components for covering the undergarment with zones of extensibility ", presented on July 20, 1994, in the name of Weinberger, and others. An optional component that can be included in the sanitary napkin 20 of the present invention is a means of odor control; any suitable odor control means can be incorporated into the sanitary napkin of the present invention in any desired form, in accordance with techniques well known in the art. In an alternate embodiment illustrated in Figure 5, a sanitary napkin 20 similar to that illustrated in Figures 1 and 2, with an expansion layer 46 characterizing the same predetermined profile as that illustrated in Figure 2, further comprises a layer of acquisition or secondary upper sheet 29 located between the upper sheet 24 and the absorbent core 28. Preferably, the acquisition layer 29 does not lie completely on the absorbent core 28; in the embodiment illustrated in Figure 5 the acquisition layer 29 does not cover the expansion layer 46 which is, therefore, capable of receiving the body fluids directly through the top sheet 24. As illustrated in Figure 5 , the acquisition layer 29 has a discontinuous surface comprising a window, which is slightly larger and wider than the expansion layer 46; therefore, the acquisition layer 29 is actually comprised between the topsheet 24 and the substantially unexpanded absorbent member 44 of the absorbent core 28. Alternate configurations are also possible, for example, the acquisition layer 29 may comprise two narrow strips longitudinally oriented and located on the absorbent element 44 of the absorbent core 28 on both sides of the expansion layer 46. Alternatively, the acquisition layer 29 may be comprised between the absorbent core 28 and the backsheet 26; furthermore, the acquisition layer 29 can be comprised between the expansion layer 46 and the absorbent element 44 in a similar fashion to that illustrated in Figure 2. The acquisition layer 29 can serve several functions, including improving the capillary action of bodily fluids which can escape laterally from the expansion layer 46, or, alternatively, which can reach the acquisition layer 29 directly, on and towards the absorbent element 44 of the absorbent core 28. For improving the capillary action of fluids bodily, the acquisition layer 29 provides a more even distribution of bodily fluids throughout the absorbent core 28. The acquisition layer 29 preferably comprises materials that are capable of acquiring liquids very rapidly and subsequently releasing them to the adjacent layers without substantially retention. The acquisition layer 29 may be comprised of several different materials including non-woven or woven webs of synthetic fibers including polyester, polypropylene or polyethylene; natural fibers including cotton or cellulose; mixtures of these fibers; or any of the equivalent materials or combinations of materials. Examples of sanitary napkins having an acquisition layer and a top sheet are more fully described in U.S. Pat. No. 4, 950,264 issued to Osborn and in U.S. Patent Application Serial No. 07 / 810,774, "Absorbent Article Having Melted Coats", filed on December 17, 1991 in the name of Cree, et al. The topsheet 24, the acquisition layer 29 and the absorbent core 28 may also be associated in any suitable manner, in order to ensure proper transfer of the fluid therebetween. In a further alternate embodiment that is not illustrated, the acquisition layer 29 may be interposed between the topsheet 24 and the absorbent core underlying a 28 comprising the expansion layer 46.; the acquisition layer 29 must be left free to follow the expansion of the expansion layer 46 upon the absorption of liquid, without limiting its swelling. As illustrated in Figure 5, the folds or bends 52 are located on both sides of the longitudinal centerline OO and substantially parallel thereto, but in each fold or fold 52 the topsheet 24 is bent twice on itself towards the longitudinal central line OO of the sanitary napkin 20. During the swelling of the expansion layer 46 towards the predetermined wet profile upon the occurrence of fluid absorption, the unraveling of the pleats or folds 52 form a type of laterally oriented lateral bend 47 which provides a better seal against lateral leaks, as illustrated in figure 6; the side bends 47 may still be present when the swelling of the expansion layer 43 is completed, if the total width of the top sheet 24 is slightly greater than that which would be necessary to follow the complete swelling of the expansion layer 46. Although the disposable absorbent article of the present invention has been described with reference to a sanitary napkin, this can be beneficially used in the context of other disposable absorbent articles, such as panty liners, incontinence articles and diapers. The disposable absorbent article can, thus, also have all those characteristics and parts that are typical for products within the context of their intended use.

Claims (10)

1. A disposable absorbent article for use adjacent to the discharge area of the body, the article having a longitudinal center line and a lateral center line orthogonal to it and defining the longitudinal and lateral directions respectively, the article having also a Z direction which is orthogonal in both longitudinal and lateral directions, said article comprising a liquid permeable upper sheet, a back sheet attached to the upper sheet, an intermediate absorbent core to the upper sheet and the back sheet, the absorbent core comprising an expansion layer for expanding the article towards a three-dimensional structure while being used by a user, the expansion layer having a surface facing the body and a surface facing the garment and which is activated by the bodily fluids, said absorbent article characterized in that said expansion layer has a predetermined profile in the d Z direction in the dry state before being used, said expansion layer being able in addition to, when fully activated by the bodily fluids, expand in a predetermined wet profile.

2. A disposable absorbent article according to claim 1, characterized in that said absorbent article is substantially planar before being used.

3. A disposable absorbent article according to any preceding claim, characterized in that said expansion layer upon activation by the body fluids expands, according to said predetermined profile, substantially in the Z direction to provide the three-dimensional structure.

4. A disposable absorbent article according to any preceding claim, characterized in that said predetermined profile is provided on the surface facing the body of the expansion layer.

5. A disposable absorbent article according to any preceding claim, characterized in that said predetermined profile of the expansion layer is provided by a non-uniform thickness of the expansion layer.

6. A disposable absorbent article according to any preceding claim, characterized in that said predetermined wet profile is such that said expansion layer provides said article with a configuration substantially convex upward. A disposable absorbent article according to any preceding claim, characterized in that the topsheet is capable of expanding as the absorbent article expands toward the three-dimensional structure upon activation by body fluids. A disposable absorbent article according to any preceding claim, characterized in that the expansion layer comprises a compressed sponge sheet of regenerated cellulose having a dry density from

0. 1 g / cm3 to 1 g / cm3. 9. A disposable absorbent article according to claim 6, characterized in that the compressed sponge sheet of regenerated cellulose has a thickness of from 0.2 millimeters to 5 millimeters. 10. An absorbent article according to any preceding claim, characterized in that the disposable absorbent article is a sanitary napkin or a pantyhose.