Disposable absorbent article having an expanding topsheet and being capable of self-shaping in use

FIELD OF THE INVENTION

The present invention relates to disposable absorbent articles. Absorbent disposable articles are absorbent devices designed to be worn externally on a user's body and to accept fluids released by the body. In particular, the present invention relates to substantially flat, disposable, absorbent sanitary napkins, catamenial pads, incontinent briefs, panty liners and diapers having a layer of compressed, regenerated cellulose sponge to expand the article into a three-dimensional structure as it is worn by a user , The layer of compressed, regenerated cellulose sponge is activated by body fluids and provides the article with a self-forming capability during use.

BACKGROUND OF THE INVENTION

In their basic form, disposable absorbent articles comprise an absorbent core disposed between a permeable body-contacting element (alternatively referred to as a topsheet or wrapper) and an impermeable protective barrier (alternatively referred to as a backsheet). Of course, the absorbent element is intended to receive and hold the fluids delivered by the body. The body contacting element is intended to provide comfortable and dry contact with the body surfaces while allowing free passage of fluids into the absorbent element. The protective barrier is intended to prevent the fluids which are expelled or which escape from the absorbent element from soiling the user's laundry.

In addition to the three functional elements mentioned above, disposable absorbent articles are generally provided with means for assisting the device adjacent to the user's crotch area, even as the user moves, which can most effectively implement their intended function. Typically, absorbent articles, such as sanitary napkins, are provided with adhesive attachment means for securing the device to the inner crotch region of the user's undergarment.

Improved fluid collection may occur when the absorbent article is in close contact with the body of the wearer.

Although previously known absorbent articles fulfill their intended function, any conventional design can be improved in one or more of absorbency properties of body fluids, protection of the user's underwear from soiling, and / or physical comfort for the user.

With regard to disposable sanitary napkins, several prior art attempts have been made to improve body contact with the wearer and thus to absorb fluids upon excretion and thereby minimize fouling by providing a sanitary napkin having an anatomically shaped configuration, particularly including those who are raised in their medial areas to the top or have a hump, so as to be close to or in contact with the pubic area when worn.

For women, these sanitary napkins were designed to contact and instantly absorb menstrual fluids as they leave the vestibule.

Some articles have also been described in which an anatomically shaped configuration is created during the wearing period, with the advantage of better anatomical fit.

US Patent No. 3,736,931 discloses a sanitary napkin having an outer, uncompressed layer of fluid absorbent material and an inner core of a highly compressed, fluid absorbent material which is at least partially enclosed therein. The napkin is preferably V-shaped in cross section and arcuate in its longitudinal direction by pressure compression. When the napkin is worn, the fluid is first directed into the inner compressed layer so as to cause it to swell and the outer, uncompressed layer to expand in all directions, thereby self-aligning with each wearer.

The sanitary napkin expands upon fluid absorption and can adapt itself to the anatomy of the user, but since it is not flat prior to use, it may be cumbersome to package and handle; moreover, the expansion takes place mainly in a transverse direction so as to provide an effective seal against the inner side of the thighs and on both sides of the vaginal opening; therefore, the structure is incapable of forming a convex upward configuration, nor does it bring the absorbent member into direct contact with the release site of the fluid.

U.S. Patent No. 3,512,530 discloses a sanitary napkin in which a compressed regenerated cellulose sponge layer is combined with a larger, fibrous cellulosic layer to form a multi-layer absorbent core. The compressed regenerated cellulose sponge layer is positioned over the fibrous layer and is typically centered about it; it is thought of as the primary absorbent element of the sanitary napkin, whereas the fibrous layer acts as a secondary or auxiliary absorbent.

The sanitary napkin may therefore be very thin prior to use compared to other sanitary products having the same absorbent capacity.

Although the compressed cellulosic regenerated sponge layer is capable of expanding in Z-direction upon fluid absorption, the described structure is not particularly well suited to provide effective body contact with the wearer's anatomy and may be useful to the user due to the characteristics of the compressed, regenerated cellulose spongy material, especially when it is dry, becoming uncomfortable.

EP Patent 293 208 B1 describes the use of multiple layers of compressed, regenerated cellulose sponge layers in a sanitary napkin as the sole absorbent material in place of the ordinary absorbent pulp core to provide an absorbent article of improved strength and dimensional stability in wet conditions as compared to traditional absorbent articles having flocked cores which tend to break when used or to form lumps.

The sheets are provided with slots to increase their flexibility, with better comfort for the user, and to increase the fluid-absorbing area.

The sanitary napkin described in EP Patent 293 208 B1 has a structure which is not specifically intended to provide a self-forming capability during use by virtue of swelling the absorbent material, but rather to provide better strength when wet, as articles using conventional flake-based absorbent cores, and to provide better flexibility and absorption rate compared to articles, using the same, compressed, regenerated cellulose spongy material.

WO 96/19168 A, which falls under Art. 54 (3), relates to a disposable absorbent article for wearing adjacent to a body exudate area which is substantially flat prior to use. The substantially flat disposable absorbent article has a longitudinal centerline and a transverse centerline perpendicular thereto, each defining a longitudinal and transverse direction, and a Z-direction being perpendicular to both. The disposable absorbent article comprises a liquid pervious topsheet, a backsheet, preferably liquid impermeable backsheet, and an absorbent core between the topsheet and the backsheet. The term "substantially flat" as used herein refers to articles that have their main extension in a plane as opposed to being shaped. The absorbent core comprises a sheet of compressed, regenerated cellulose sponge for expanding the article into a three-dimensional structure when worn by a user, wherein the sheet of compressed, regenerated cellulose sponge is activated by body fluids. The topsheet is capable of expanding the absorbent article upon activation by the body fluids.

WO-A-95/00091 and SO-A-95/27457 are also of interest to the invention.

Therefore, there is still a need for an absorbent article capable of providing an anatomically shaped configuration for closer body contact obtained during use upon activation by absorbed bodily fluids while being comfortable for the wearer and which is easy to make and pack.

The features of the present invention are disclosed in claim 1. Preferred embodiments are defined in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Although the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed that the present invention will be better understood from the following description when taken in conjunction with the following drawings:

Fig. 1 is a plan view of an embodiment of a sanitary napkin according to the present invention;

Fig. 2 is a cross-sectional view of the sanitary napkin shown in Fig. 1 taken along a section line corresponding to the transverse center line AA;

Fig. 3 is a cross-sectional view similar to that of Fig. 2, showing the sanitary napkin expanded into a three-dimensional structure upon activation during wear;

Fig. 4 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 napkin expanded in a three-dimensional structure upon activation during wear.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to a disposable absorbent article which exhibits body fluid absorbency, protection of the user's laundry from soiling, improved physical comfort for the user, and which is easy to manufacture and package. The disposable absorbent article is described below with reference to a sanitary napkin or catamenial pad. The term "sanitary napkin" as used herein refers to an article which is worn by women adjacent to the pubic area and which is intended to absorb and receive various bodily fluids which are released from the body (e.g., vaginal exudates , Menstrual fluids and / or urine) and which is intended to be discarded after a single use. The disposable absorbent article is substantially flat prior to use.

The term "substantially flat" as used herein refers to articles that have their main extension in a plane as opposed to being shaped. In a preferred embodiment, a substantially flat article has a constant thickness absorbent core or, at least, has an absorbent core that is not formed in a direction that is perpendicular to the absorbent core itself. This does not preclude a general curvature of the absorbent core. It will be apparent to one skilled in the art to what extent products may deviate from an absolutely flat shape and still benefit from molding during use in accordance with the present invention.

Sanitary napkins having elongated side cuffs, which may optionally be elasticized, and sanitary napkins having a moderate curvature are therefore within the scope of the present invention, provided that their absorbent core is not shaped in a direction perpendicular to the absorbent core itself prior to use ,

The term "use" as used herein refers to the amount of time that begins when the absorbent article is actually brought into contact with the anatomy of the user.

As used herein, the terms "connected" or "attached" include configurations by which a first element is directly connected to a second element and configurations by which a first element is indirectly connected to a second element by the first element is connected to intermediate elements, which in turn are connected to the second element.

Interlabial devices, partially seated within and partially outside the wearer's vestibule, are also within the scope of this invention. As used herein, the term "shame" refers to the externally visible female genitalia and is limited to the labia majora, the labia minora, the clitoris, and the vestibule.

Referring now to Figures 1 and 2, there is shown a preferred embodiment of a sanitary napkin 20 of the present invention. Figure 1 is a plan view of the sanitary napkin 20 of the present invention in its laid-flat condition prior to use, with portions of the structure cut away to more clearly show the construction of the sanitary napkin 20 and the portion of the sanitary napkin 20 facing the wearer is directed or touches it, is directed opposite to the viewer. As in Figs. 1 2, the sanitary napkin 20 preferably comprises a liquid pervious topsheet 24, a liquid impermeable backsheet 26 joined to the topsheet 24, and an absorbent core 28 interposed between the topsheet 24 and the backsheet 26 which is a sheet of material compressed regenerated cellulose sponge 46 for expanding the sanitary napkin into a three-dimensional structure when worn by a user.

The sanitary napkin 20 has two surfaces, a body-contacting or bodyside surface, and a garment-facing or contacting surface. The absorbent core 28 has a corresponding bodyside and garment surface. The sanitary napkin 20 has two centerlines, a longitudinal centerline OO and a transverse centerline AA at right angles thereto. The term "longitudinal" as used herein refers to a line, axis or direction in the plane of the sanitary napkin 20 that is substantially aligned with (eg, approximately parallel to) a vertical plane that is a stationary one Carrier divides into left and right body halves when the sanitary napkin 20 is worn. The terms "transverse" or "lateral" as used herein are interchangeable and refer to a line, axis or direction which lies within the plane of the sanitary napkin 20 and is substantially perpendicular to the longitudinal direction. The Z-direction is orthogonal to both the longitudinal and transverse directions of the sanitary napkin 20 and extends outwardly from the plane of the sanitary napkin 20 defined by the longitudinal centerline OO and the transverse centerline AA. The term "longitudinally oriented" refers to a direction ± 45 degrees from the longitudinal direction in the plane of a sanitary napkin 20; The term "cross-oriented" similarly refers 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 edges of the sanitary napkin 20. The ends of the sanitary napkin 20 connecting the longitudinal side edges are the transverse ends of the sanitary napkin 20. Together, the longitudinal side edges and the transverse ends define the sanitary napkin 20 its scope. Similarly, the absorbent core 28 of the sanitary napkin 20 has a circumference bounded by alternating longitudinal side edges and transverse ends.

Three-dimensional structures of the sanitary napkin 20 are those in which the structure of the sanitary napkin is caused to expand, at least in part, in the Z-direction, to conform more closely to the anatomy of the user. The expansion preferably occurs in a direction extending from the garment facing surface toward the bodyside surface of the sanitary napkin 20. Particularly preferred are three-dimensional structures having a convex upward configuration including, but not limited to, inverted U-shapes or inverted V-shapes. With these configurations, the contour of the cross-section of the central portion of the sanitary napkin conforms more closely to the labia of the typical wearer.

The topsheet 24 is compliant, soft feeling, and non-irritating to the wearer's skin. Further, the topsheet 24 is liquid permeable and allows a liquid to readily penetrate through its thickness. A suitable topsheet 24 may be made of a wide range of materials, such as woven and nonwoven materials; polymeric materials such as open-formed thermoplastic films, open plastic films, and hydroformed thermoplastic films; porous foams; reticulated foams; reticulated thermoplastic films; and thermoplastic scrims. Suitable woven and nonwoven materials may be composed of natural fibers (e.g. Wood or cotton fibers), synthetic fibers (eg, polymeric fibers such as polyester, polypropylene, or polyethylene fibers); or a combination of natural and synthetic fibers.

A preferred topsheet comprises an open-formed film. Open-formed films are preferred as the topsheet because they are permeable to body fluids and are not yet absorbent and have a reduced tendency to allow fluids to pass back through them and rewet the wearer's skin. In this way, the surface of the formed film which is in contact with the body remains dry, thereby reducing body soiling and creating a more comfortable feel for the wearer.

Suitable shaped 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 et al. on April 13, 1982; U.S. Patent No. 4,342,314 issued to Radel et al. on August 3, 1982, US Pat. No. 4,463,045 issued to Ahr et al. on July 31, 1984; and U.S. Patent No. 5,006,394 issued to Baird on April 9, 1991. A preferred topsheet of the absorbent article of the present invention is a formed film described in one or more of the above patents and marketed on sanitary napkins by The Procter & Gamble Company of Cincinnati, Ohio, as "DRI-WEAVE".

In a preferred embodiment of the present invention, the body or exposed surface of the formed film topsheet is hydrophilic so as to help transfer liquid through the topsheet faster than if the bodyside surface were not hydrophilic so as to reduce the likelihood of that a menstrual fluid flows out of the topsheet instead of flowing into and being absorbed by the absorbent core.

The topsheet of the present invention must be able to expand as the sanitary napkin 20 expands into a three-dimensional structure upon absorption of body fluids. This can be achieved if the topsheet is made of a material that is intrinsically extensible under the forces exerted by the expanding sheet of the compressed regenerated cellulose sponge. In a preferred embodiment, which in Figs. 1 2 and 2, the topsheet 24 is provided with two pleats or pleats 52 which are symmetrically positioned on both sides of the longitudinal centerline OO and substantially parallel thereto. As shown in FIG. 2, the topsheet 24 in each pleat or pleat 52 is folded twice on itself toward the longitudinal side edges of the sanitary napkin 20. A single pleat or pleat or, alternatively, more than two pleats may also be present in the topsheet 24 without departing from the scope of the present invention; the pleats or folds may be substantially longitudinal or transverse.

The absorbent core 28 may comprise any absorbent means which is substantially compressible, elastic, non-irritating to the skin of the wearer and capable of absorbing and receiving body fluids. The absorbent core 28 can be made 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 milled wood pulp (which is commonly referred to as airfelt), creped cellulose wadding; Modified, crosslinked cellulosic fibers (such as those described in US Patent No. 5,217,445, issued to Young et al., June 8, 1993), fibers with capillary channels (that is, fibers having capillary intervening fiber channels as described in US Pat 5,200, 248, issued to Thompson et al. Absorbent foams (such as those described in U.S. Patent No. 5,260,345, issued to DesMarais et al., November 9, 1993, and U.S. Patent No. 5,268,244 issued to DesMarais et al., December 7, 1993) 1993); thermally bonded airlaid materials (such as such a material described in US patent application Ser. 08 / 141,156 entitled "Catamenial Absorbent Structures Having Thermally Bonded Layers For Improved Handling of Menstrual Fluids and Their Use in Catamenial Pads Having Improved Fit and Comfort" filed on behalf of Richards et al. on October 21, 1993 (P & G Case 5051)), absorbent sponges, synthetic staple fibers, polymeric fibers, hydrogel-forming polymeric gelling agents, peat moss, or any equivalent materials or combinations of materials. Suitable absorbent cores with foams are disclosed in European Patent Applications 0 598 833, 0 598 823 and 0 598 834.

In the embodiments shown in Figs. 1-3, the absorbent core 28 comprises an absorbent layer 30 of thermally bonded, airlaid material folded longitudinally two times upon itself and having particles of absorbent gelling material therebetween which, for clarity, do not are shown.

The absorbent core 28 further comprises a sheet of compressed, regenerated cellulose sponge 46 for expanding the sanitary napkin 20 into the desired three-dimensional structure when the sanitary napkin 20 is worn. In a in Figs. 1 3 to 3, the expansion and final shaping of the sanitary napkin 20 in the three-dimensional structure is provided by swelling, substantially in the Z direction, of the material forming the compressed regenerated cellulose sponge 46 sheet, and through the fabric during wear Absorption of body fluids is activated.

The compressed, regenerated cellulose sponge layer 46 forms at least a portion of the bodyside surface of the absorbent core 28 in side-by-side relationship therewith; it is preferably narrower and shorter than the absorbent layer 30 as shown in Figure 1 and centered about both the longitudinal and transverse centerlines OO and AA.

The regenerated cellulose sponge is a material known in the art; Examples of suitable materials are described in US Patent No. 3,954,493, French Patent Application FR-A-2,203,827 and European Patent EP-B-0 293 208. The regenerated cellulose sponge is a sponge made of a material containing a cellulosic skeleton. Examples of such 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 such materials.

For example only, a regenerated cellulose sponge can be prepared from a mixture of a viscose solution with reinforcing fibers and a porogenic compound, e.g. For example, crystals of sodium sulfate decahydrate or other alkali metal salt with a high content of crystallized water, wherein the final pore size is related to that of the salt crystals. The viscose solution can be extruded through an extrusion die of the desired cross-section and then coagulated. The material is washed with water after regeneration 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 generated by the removal of the sodium sulfate crystals.

The compressed, regenerated cellulose spongy material is available in various forms, e.g. B. in layers or layers of different densities, thicknesses and basis weights; Dry density values ​​for the compressed material used in the present invention are from 0.1 g / cc to 1 g / cc, while the thicknesses can range from 0.5 mm to 5 mm.

These low thicknesses are particularly preferred for the compressed regenerated cellulose sponge sheets used in the present invention to have a material that is flexible in its dry state prior to activation by body fluids.

In a preferred embodiment of the present invention shown in Figs. 1 and 2, a sheet 46 is of compressed, regenerated cellulose sponge having a dry density of 0.5 g / cc and a thickness of 2 mm over the absorbent core 28 positioned in a page-wise relationship with this. The absorbent layer 30 is 207 mm long and 64 mm wide, and the compressed regenerated cellulose sponge sheet 46 is 125 mm long and 30 mm wide and centered about both the longitudinal and transverse centerlines OO and AA of the sanitary napkin 20 , Suitable sheets of compressed, regenerated cellulose sponge may be those made by Spontex France. Different shapes are also possible for the compressed regenerated cellulose batting 46, e.g. B. an hourglass shape.

The absorbent layer 30 and the compressed, regenerated cellulose sponge layer 46 may be joined in any suitable manner to form the absorbent core 28. Suitable manners include, but are not limited to, bonding the absorbent layer 30 to the compressed regenerated cellulose sponge sheet 46 with adhesives, such as by spray bonding or by applying lines or spots of adhesive therebetween.

Alternatively or additionally, the connection between the layers may be achieved by fiber entanglement or by a plurality of discrete fusion bonds.

The compressed regenerated cellulosic sponge layer 46 is capable of rapidly absorbing body fluids with a large increase in volume, generally about 2 to 20 times and usually 5 to 15 times their volume at the time of compression. The volume increase essentially corresponds to swelling in the direction of compression, that is, in the Z direction in the sanitary napkin 20.

The sanitary napkin 20 is manufactured and packaged as a conventional flat product, as shown in Figs. 1 and 2. After the sanitary napkin 20 has been worn, once the absorbed body fluids come in contact with the material of the compressed, regenerated cellulose sponge pad 46, it begins to swell in the Z direction, increasing its thickness, as can be seen in FIG. The topsheet 24 follows swelling of the compressed regenerated cellulose sponge sheet 46 by unfolding the pleats 52, therefore, without restraining the swelling process.

After absorption of the bodily fluids and subsequent swelling, the material of the compressed, regenerated cellulose sponge pad 46 is soft, pliant, deformable and elastic. It is compressible enough to deform under the relatively small forces exerted during normal use. In addition to being compressible, the material of the compressed, regenerated cellulose sponge layer 46 after swelling is flexible and deformable such that it is capable of providing improved fit through the topsheet 24 in and around the wearer's labia and perineum create when the three-dimensional structure is formed during the wearing time. The ability to follow the topography of anatomy provides intimate contact with the exposed genitalia of the user. This helps to provide better fluid transfer from the user to the compressed, regenerated cellulose sponge layer 46. While these properties provide improved seating for the compressed regenerated cellulose sponge pad 46, the product also provides the wearer with a soft and comfortable feel.

The swelling action upon liquid absorption of the compressed, regenerated cellulose spongy material forming the sheet 46 creates a void volume which does not coincide in wet states and therefore enables the material to immediately accept further releases of fluid and deliver it to the underlying absorbent layer 30 convict.

The total absorbent capacity of the absorbent core 28 of the sanitary napkin 20 is therefore essentially provided by the combination of the compressed, regenerated cellulose sponge layer 46 with the absorbent layer 30.

The total absorbent capacity of the absorbent core 28 with the compressed, regenerated cellulose sponge layer 46 should be compatible with the intended body fluid load for the sanitary napkin 20. Further, the total absorbent capacity of the absorbent core 28 can be varied to accommodate wearers that vary in the expected amount of body fluid volume. For example, a different absorbent capacity may be used for sanitary napkins intended for daytime use, as compared to those intended for nighttime use, or sanitary napkins intended for use by teenagers, as compared to those for adult women are meant.

In another embodiment of the present invention, the compressed, regenerated loose sponge layer 46 may completely form the absorbent core 28 of the sanitary napkin 20. The total absorbent capacity of the sanitary napkin 20 in this case is provided only by the compressed, regenerated cellulose sponge layer 46.

The traverse of the material forming the compressed, regenerated cellulose sponge layer 46 occurs only upon activation by the absorbed fluid; that is, only during use of the sanitary napkin 20 and in close contact with the anatomy of the user; the formation of the three-dimensional structure can therefore achieve a much better fit with the anatomy of the user. Moreover, the transverse action of the compressed, regenerated cellulose sponge layer 46 may begin where it is actually reached by the fluid first; The formation of the three-dimensional structure can therefore also be adapted to the different possible ways in which the body fluids are released by different users.

The expanding topsheet 24 also provides comfortable contact with the anatomy of the user without restricting 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 flat prior to use and therefore can be packaged more easily than a conventional, elasticized or preformed article. Since the three-dimensional structure is formed only during use, the sanitary napkin of the present invention is also easier to wear.

In an alternative embodiment of the present invention, the sanitary napkin 20 may have two flaps (not shown), each adjacent to and extending laterally from the side edge of the absorbent core. The flaps are configured to fall over the edges of the wearer's panties in the crotch region so that the flaps are disposed between the edges of the wearer's panties and thighs of the wearer. The flaps serve at least two purposes. First, the flaps help prevent soiling of the wearer's body and panties by menstrual fluid, preferably by forming a double-walled barrier along the edges of the panty. Second, the flaps are preferably provided with attachment means on their garment surface so that the flaps can be folded back under the panty and attached to the garment facing side of the panty. In this way, the flaps serve to keep the sanitary napkin properly positioned in the panty.

The flaps may be constructed of various materials, including materials used for topsheet 24, backsheet 26, combinations thereof, and may be a laminate having a tissue in the center. Further, the flaps may include a separate element attached to the main body of the sanitary napkin 20, or may include extensions of the topsheet 24 and / or the backsheet 26. However, it is recommended that the flaps have a liquid-impermeable backsheet to prevent bodily fluids reaching the flaps from soiling the edges of the wearer's panties.

Preferred flaps suitable for or conformable with 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 which, of course, encase the sides of the wearer's panties. Sanitary napkins having components naturally wrapping the sides of the wearer's panties suitable for use with the sanitary napkin 20 of the present invention are disclosed in U.S. Patent Application Serial No. 08 / 811,099. 08 / 096,121, entitled "Absorbent Article having Panty Covering Components that Naturally Wrap the Sides of Panties", filed July 22, 1993 in the name of Lavash et al. and U.S. Patent Application Serial No. 08 / 277,222, entitled "Absorbent Articles Having Undergarment Covering Components with Zones of Extensibility" filed July 20, 1994 in the name of Weinberger et al.

The compressed, regenerated cellulosic sponge layer 46 for expanding the sanitary napkin 20 into a three-dimensional structure during wear may be contained in the sanitary napkin 20 in any other suitable position and / or orientation to obtain the desired three-dimensional structure, in particular, the compressed, regenerated cellulose sponge layer 46 form at least part of the garment surface of the absorbent core 28.

In an alternative embodiment shown in FIG. 4, a sanitary napkin 20 similar to that shown in FIGS. 1 and 2 further includes an acquisition layer or secondary topsheet 29 positioned between the topsheet 24 and the absorbent core 28. Preferably, the acquisition layer 29 does not overlay the compressed, regenerated cellulose sponge layer 46, which is therefore capable of receiving body fluids directly through the topsheet 24. As shown in FIG. 4 is shown, the acquisition layer 29 has a discontinuous surface with a window which is slightly longer and wider than the compressed, regenerated cellulose sponge layer 46. Other embodiments may also be possible, e.g. For example, the acquisition layer 29 may comprise two narrow strips longitudinally oriented and positioned over the absorbent core 28 on both sides of the compressed, regenerated cellulose sponge layer 46. Alternatively, the acquisition layer 29 may be included between the absorbent core 28 and the backsheet 26, and the acquisition layer 29 may be included between the compressed regenerated cellulose sponge layer 46 and the absorbent core 30 in an embodiment similar to that shown in FIG. 2 ,

The acquisition layer 29 may serve a number of functions, including enhancing suction for body fluids that escape laterally from the compressed, regenerated cellulose sponge layer 46, or alternatively directly reach the acquisition layer, over and into the absorbent core 28. By improving the wicking effect on body fluids, the acquisition layer 29 provides a uniform distribution of body fluids in the absorbent core 28.

The acquisition layer 29 preferably comprises materials capable of accepting a liquid very rapidly and subsequently delivering it to adjacent layers having substantially no retention capacity.

The acquisition layer 29 may be composed of a number of different materials, including nonwoven or fabric webs of synthetic fibers with polyester, polypropylene or polyethylene; natural fibers, including cotton or cellulose; Mixtures of such fibers; or any equivalent materials or combinations of materials. Examples of sanitary napkins having an acquisition layer and a topsheet are more fully described in US Pat. 4,950,264, issued to Osborn and U.S. Patent Application Serial No. 07 / 810,774, "Absorbent Article Having Fused Layers", filed 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 joined in any suitable manner to ensure proper fluid transfer therebetween. In another alternative embodiment, not shown, the acquisition layer 29 may be positioned between the topsheet 24 and the underlying absorbent core 28 having the compressed, regenerated cellulose sponge layer 46; the acquisition layer 29 must remain free to follow the expansion of the compressed, regenerated cellulose sponge layer 46 upon absorption of a fluid without limiting the swelling process.

As shown in Figure 4, the pleats 52 are positioned on and substantially parallel to the longitudinal centerline OO, but in each pleat 52, the topsheet 24 is twice on itself in the direction of the longitudinal Sanitary napkin 20 centerline OO folded. During the swelling action of the compressed, regenerated cellulose sponge layer 46 upon fluid absorption, the deployment of the pleats or pleats 52 forms a type of longitudinally oriented side cuffs 47 which provide a better seal against side leakage, as shown in FIG. 5 is shown; the side cuffs 47 may still be present if the swelling process of the compressed, regenerated cellulose sponge ply 46 is completed, if the total width of the topsheet 24 is a little higher than that which would be necessary to follow the complete swelling of the compressed, regenerated cellulose sponge ply 46.