Patent Description:
A variety of well-known absorbent articles are configured to absorb body fluids. Examples of such absorbent articles include, but are not limited to, feminine hygiene products, such as sanitary napkins, baby diapers, adult incontinence products, and bandages. A typical absorbent article is generally constructed with a fluid permeable user-facing topsheet, which may be a three dimensional apertured polymer film or a nonwoven web or a film/nonwoven laminate, an absorbent core and a fluid impermeable garment or outwardly-facing backsheet, which may be a solid polymer film, for example.

A potential problem associated with absorbent articles may be the perceived lack of dryness of the user-facing topsheet of the absorbent article. Generally, the drier the skin feels that is contacting topsheet, the more comfortable the absorbent article. In many instances, surface dryness of the topsheet may be correlated to fluid strikethrough efficiency. If the layer(s) beneath the topsheet are inefficient in fully pulling the fluid out of the topsheet, residual wetness can remain. Moreover, wetness may reoccur and contribute to residual wetness if the fluid is allowed to move from the layer(s) beneath the topsheet and back through the topsheet when the absorbent article is subjected to pressure, which is a typical condition when the article is being worn by a user.

One or more additional layers may be added to the absorbent article in between the topsheet and absorbent core to improve fluid acquisition out of the topsheet and/or fluid distribution across the absorbent core so that the fluid may be pulled through and out of the topsheet and into the absorbent core more quickly and/or more completely. The additional layer may be in the form of a nonwoven material, such as the liquid management layer described in <CIT> or may be in the form of a three dimensional apertured film, such as the acquisition distribution layer described in <CIT> or the acquisition/distribution layer described in <CIT> for example. However, such an additional layer adds cost to the final article and may also increase the thickness or bulkiness and/or stiffness of the article. Efforts to minimize the amount of material that is used in an additional layer by, for example, downgauging, particularly for a film, may be challenging because downgauging may reduce the modulus of the material and negatively impact the ability to incorporate the layer into the final absorbent article during conversion processes. Document <CIT> discloses a fluid distribution material.

It is desirable to provide a fluid distribution material that reduces residual wetness, even after the absorbent article is subjected to pressure, and has a modulus sufficient to allow the fluid distribution material to be converted into an absorbent article.

According to an aspect of the invention, there is provided a fluid distribution material for use in an absorbent article. The fluid distribution material includes a formed film layer which comprises one or more polyolefins, the formed film layer (<NUM>) having a user-facing side and a garment-facing side opposite the user-facing side The formed film layer includes a plurality of apertured protuberances arranged in a pattern having <NUM> to <NUM> protuberances per linear <NUM> corresponding to <NUM> inch. Each of the protuberances includes a continuous sidewall extending from the user-facing side, and the garment-facing side has a plurality of apertures aligned with the plurality of apertured protuberances, and land areas in between the apertures. The formed film layer has a basis weight of between about <NUM> gsm and about <NUM> gsm. A nonwoven layer is laminated to the garment-facing side of the formed film layer. The nonwoven layer includes a plurality of fibers attached to the formed film layer at the land areas, and has a basis weight of between about <NUM> gsm and about <NUM> gsm. The fluid distribution material has a rewet value of less than <NUM> grams in accordance with the Rewet Test Method described herein. The fluid distribution material has a compressibility of less than <NUM>% between pressures of <NUM> kPa and <NUM> kPa, corresponding to <NUM> psi and <NUM> psi, respectively.

In an embodiment, the plurality of apertured protuberances are arranged in a pattern having <NUM> to <NUM> protuberances per <NUM> corresponding to <NUM> inch.

In an embodiment, the formed film layer includes a surfactant.

In an embodiment, the nonwoven layer includes a spunbond nonwoven. In an embodiment, the spunbond nonwoven is hydrophilic.

In an embodiment, the formed film layer is high density polyethylene (HDPE).

According to an aspect of the invention, there is provided a fluid management system for use in an absorbent article. according to claim <NUM>. The fluid management system includes a fluid distribution material that includes a formed film layer having a user-facing side and a garment-facing side opposite the user-facing side. The formed film layer includes a plurality of apertured protuberances arranged in a pattern having <NUM> to <NUM> protuberances per linear <NUM> corresponding to <NUM> inch. Each of the protuberances includes a continuous sidewall extending from the user-facing side, and the garment-facing side has a plurality of apertures aligned with the plurality of apertured protuberances, and land areas in between the apertures. The formed film layer has a basis weight of between about <NUM> gsm and about <NUM> gsm. The fluid distribution material also includes a nonwoven layer laminated to the garment-facing side of the formed film layer. The nonwoven layer includes a plurality of fibers attached to the formed film layer at the land areas and has a basis weight of between about <NUM> gsm and about <NUM> gsm. The fluid management system also includes a topsheet attached to the fluid distribution material. The user-facing side of the formed film layer faces the topsheet. The fluid distribution material has a rewet value of less than <NUM> grams in accordance with the Rewet Test Method. The fluid distribution material has a compressibility of less than <NUM>% between pressures of <NUM> kPa and <NUM> kPa, corresponding to <NUM> psi and <NUM> psi, respectively.

In an embodiment, the topsheet includes an apertured formed film.

In an embodiment, the topsheet includes a nonwoven web.

In an embodiment, the topsheet includes a laminate.

According to an aspect of the invention, there is provided an absorbent article according to claim <NUM>.

The components of the following figures are illustrated to emphasize the general principles of the present disclosure and are not necessarily drawn to scale. Reference characters designating corresponding components are repeated as necessary throughout the figures for the sake of consistency and clarity.

Various embodiments of the present invention will now be highlighted. The discussion of any one embodiment is not intended to limit the scope of the present invention as claimed. To the contrary, aspects of the embodiments are intended to emphasize the breadth of the invention as claimed. Furthermore, any and all variations of the embodiments, now known or developed in the future, also are intended to fall within the scope of the invention as claimed.

As used herein, the expression "absorbent articles" and "absorptive devices" denote articles that absorb and contain body fluids and other body exudates. More specifically, an absorbent article/absorptive device includes garments that are placed against or in proximity to the body of a wearer to absorb and contain the various exudates discharged from a body. Non-limiting examples of absorbent articles include, but are not limited to feminine hygiene products, baby diapers, adult incontinence products, and bandages.

Throughout this description, the term "web" refers to a material capable of being wound into a roll. Webs can be film webs, nonwoven webs, laminate webs, apertured laminate webs, etc. The face of a web refers to one of its two dimensional surfaces, as opposed to one of its edges.

The term "composite web" or "composite material" refers to a web that comprises two or more separate webs that are attached to each other in a face to face relationship. The attachment can be through the edges of the component webs, although the component webs lie in a face to face relationship with each other, or the attachment can be at particular spot locations across the component webs, or the attachment can be continuous.

The term "film" or "polymer film" in this description refers to a web made by extruding a molten curtain or sheet of thermoplastic polymeric material by a cast or blown extrusion process and then cooling the sheet to form a solid polymeric web. Films can be monolayer films, coextruded films, coated films, and composite films.

"Coated films" are films comprising a monolayer or coextruded film that are subsequently coated (for example, extrusion coated, impression coated, printed, or the like) with a thin layer of the same or different material to which it is bonded.

"Composite films" are films comprising more than one film where the at least two films are combined in a bonding process. Bonding processes may incorporate adhesive layers between the film layers.

Throughout this description, the expression "apertured films" denotes films that have a plurality of holes that extend from a first surface of the film to a second surface of the film.

A "two-dimensional apertured film" is a film in which no three-dimensional structure exists in the holes, which then connect the second surface of a flat film to the first surface of the film.

A "formed film" or a "three-dimensional film" is a film with protuberances, protrusions, or extended cells extending from at least one side thereof, and an "apertured formed film" or a "three-dimensional apertured film" is a film in which a three-dimensional structure exists in the apertures (e.g., the apertures have a depth that is thicker than the thickness of the film), or the protuberances or protrusions or extended cells have apertures therethrough.

The term "protuberance" as used herein refers to a three-dimensional member comprising an apertured base portion located in the plane of the first surface of the film and a sidewall portion extending generally in the direction of the second surface of the film. Each base portion has an associated sidewall portion. Sidewall portions terminate in "ends" located in the plane of the second surface of the film. The ends of the protuberances may be apertured or unapertured.

"Apertured protuberance" as used herein refers to a protuberance that has an aperture at its base portion or proximal end in the plane of the second surface, as well as its distal or protubered end. The apertures in the base portions of the protuberances, also called "primary apertures," may be in the shape of polygons, for example squares, hexagons, pentagons, ellipses, circles, ovals, or slots, in a regulated or random pattern. In an embodiment, the apertures may be in the shape of a boat, as described in, for example, <CIT>,.

The apertured distal or protubered ends are called "secondary apertures," and may be in the shape of polygons, e.g., squares, hexagons, pentagons, ellipses, circles, ovals, slots, or boats. The sidewall portion of the apertured protuberance extends from the primary aperture to the secondary aperture.

The term "nonwoven" means a web comprising a plurality of fibers. The fibers may be bonded to each other or may be unbonded. The fibers may be staple fibers or continuous fibers or filaments. The fibers may comprise a single material or may comprise a multitude of materials, either as a combination of different fibers or as a combination of similar fibers with each comprised of different materials.

As used herein, "nonwoven web" is used in its generic sense to define a generally planar structure that is relatively flat, flexible and porous, and includes staple fibers or continuous fibers or filaments. The nonwoven web may be the product of any process for forming the same, such as nonwoven spunbond and melt blown nonwoven webs. The nonwoven web may include a composite or combination of webs. The nonwoven web may comprise any polymeric material from which a fiber can be produced and/or may comprise cotton or other natural fibers. In an embodiment, the nonwoven web may be a spunbond material, made of polypropylene fiber. Fibers that comprise different polymers may also be blended. In an embodiment, the fibers may be so-called bi-component ("bi-co") fibers that comprise a core of one material and a sheath of another material.

The term "forming structure" or "screen" as used herein refers to a three-dimensional molding apparatus that comprises indentations used to form protuberances, extended cells or apertures in films, or protuberances in nonwoven webs. In an embodiment, forming structures comprise tubular members, having a width and a diameter. In alternative embodiments, forming structures may comprise belts having a width and a length. The transverse direction is the direction parallel to the width of the forming structure. The machine direction is the direction parallel to the direction of rotation of the forming structure, and is perpendicular to the transverse direction.

As used herein, the term "activating" or "activation" refers to a process of stretching a material beyond a point where its physical properties are changed. In the case of a nonwoven web, sufficient activation of the web will result in the nonwoven web being more extensible and/or improving its tactile properties. In an activation process, forces are applied to a material causing the material to stretch. Polymer films and nonwoven webs may be mechanically activated, for example. Mechanical activation processes comprise the use of a machine or apparatus to apply forces to the web to cause stretching of the web to an extent sufficient to cause permanent deformation of the web. Methods and apparatus used for activating webs of materials include, but are not limited to, activating the web through intermeshing gears or plates, activating the web through incremental stretching, activating the web by ring rolling, activating the web by tenter frame stretching, canted wheel stretchers or bow rollers, and activating the web in the machine direction between nips or roll stacks operating at different speeds to mechanically stretch the components, and combinations thereof.

<FIG> schematically illustrates an absorbent article <NUM> in accordance with embodiments of the invention. As illustrated, the absorbent article <NUM> includes a topsheet <NUM>, a backsheet <NUM>, and an absorbent core <NUM> positioned in between the topsheet <NUM> and the backsheet <NUM>. The absorbent article <NUM> also includes a fluid distribution material <NUM> positioned in between the topsheet <NUM> and the absorbent core <NUM>.

The topsheet <NUM>, which may be in the form of a two-dimensional or three-dimensional apertured film, a nonwoven web, or a laminate of an apertured film and a nonwoven web, is permeable to fluids and is configured to face the user wearing the absorbent article <NUM> and contact the user's skin. The topsheet <NUM> receives insults of fluid from the user, and the fluid passes through the topsheet <NUM> to the fluid distribution material <NUM>. The fluid distribution material <NUM>, embodiments of which are described in further detail below, is also permeable and is configured to receive the fluid from the topsheet <NUM> and distribute the fluid to the absorbent core <NUM>. The absorbent core <NUM>, which includes absorbent materials, receives the fluid from the fluid distribution material <NUM> and stores the fluid until the absorbent article <NUM> is discarded. The backsheet <NUM>, which is impermeable to liquid and may be in the form of a polymer film or laminate of a polymer film and nonwoven web, prevents liquid and other body exudates from leaking out of the bottom side of the absorbent core <NUM>. The backsheet <NUM> may be breathable so that air, but not liquid, may pass through.

In an embodiment, the topsheet <NUM> and the fluid distribution material <NUM> may be integrally formed as a fluid management system <NUM>. For example, the topsheet <NUM> and the fluid distribution material <NUM> may be in a face to face relationship and attached to each other at their peripheries, or may be attached to each other at a plurality of locations, or continuously, across the webs to form a composite web. Such attachment may be achieved with one or more adhesives, or by thermal bonding, or by ultrasonic bonding, or by any other attachment means known in the art. In an embodiment, the absorbent article <NUM> may not include a topsheet <NUM>. If so, the fluid distribution material <NUM> may function by itself as the fluid management system and be configured to be in contact with the user wearing the absorbent article <NUM>.

<FIG> schematically illustrates a cross-section of a fluid distribution material <NUM>, which may be used as the fluid distribution material <NUM> of <FIG>, in accordance with embodiments of the invention. As illustrated, the fluid distribution material <NUM> includes a formed film layer <NUM> and a nonwoven layer <NUM>. The formed film layer <NUM> has a first side <NUM> and a second side <NUM> that is opposite the first side <NUM>. The formed film layer <NUM> includes a plurality of apertured protuberances <NUM>. Each of the apertured protuberances <NUM> includes a continuous sidewall <NUM> extending from the first side <NUM> of the formed film layer <NUM> to a distal end <NUM> that includes a secondary aperture <NUM>, as illustrated. The first side <NUM> of the formed film layer <NUM> also includes land areas <NUM> in between the apertured protuberances <NUM>.

The second side <NUM> of the formed film layer <NUM> has a plurality of primary apertures <NUM> aligned with the plurality of protuberances <NUM>. As such, the primary apertures <NUM> in the second side <NUM> of the formed film layer <NUM> are also considered to be proximal apertures <NUM> of the apertured protuberances <NUM>, while the secondary apertures <NUM> at the distal ends <NUM> of the apertured protuberances <NUM> may also be considered to be distal apertures <NUM> of the apertured protuberances <NUM>. The second side <NUM> of the formed film layer <NUM> also includes land areas <NUM> in between the proximal apertures <NUM>.

In an embodiment, the apertured protuberances <NUM> may be arranged in a pattern having about <NUM> to about <NUM> protuberances per linear <NUM> corresponding to <NUM> inch or "mesh," i.e., about <NUM> mesh to about <NUM> mesh. The pattern may be a hexagonal pattern, a square pattern, a staggered pattern, or any other type of pattern or design. In an embodiment, the apertured protuberances <NUM> may be arranged in a <NUM>-<NUM> mesh pattern. In an embodiment, the apertured protuberances <NUM> may be arranged in about an <NUM> mesh pattern. In an embodiment, the apertured protuberances <NUM> may be arranged in about a <NUM> mesh pattern. In an embodiment, the apertured protuberances <NUM> may be arranged in a <NUM> mesh pattern. In an embodiment, the proximal apertures <NUM> may be hexagonal in shape and have approximately the same size. In an embodiment, the proximal apertures <NUM> may have different sizes and/or shapes, as described in further detail below.

The polymer of the formed film layer <NUM> includes one or more polyolefins, including but not limited to polyethylene, ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, linear medium density polyethylene, high density polyethylene, polypropylene, ethylene-vinyl acetates, metallocene, as well as other polymers. Other polymers include but are not limited to elastomeric polymers, including but not limited to polypropylene based elastomers, ethylene based elastomers, copolyester based elastomers, olefin block copolymers, styrenic block copolymers and the like, or combinations thereof. Additives, such as surfactants, fillers, colorants, opacifying agents and/or other additives known in the art may also be used in the formed film layer <NUM>.

Returning to <FIG>, the nonwoven layer <NUM> has a first side <NUM> and a second side <NUM> opposite the first side <NUM>. In the illustrated embodiment, the first side <NUM> of the nonwoven layer <NUM> contacts the second side <NUM> of the formed film layer <NUM>. The nonwoven layer <NUM> includes a plurality of fibers <NUM>.

Nonwoven webs that may be used for the nonwoven layer <NUM> may be formed from many processes, including but not limited to spunbonding processes, melt-blowing processes, hydroentangling processes, spunlacing processes, air-laying, and bonded carded web processes, or combinations thereof, as are known in the nonwoven art. In an embodiment, the nonwoven layer <NUM> may be a spunbonded nonwoven web. In an embodiment, the fibers <NUM> in the nonwoven layer <NUM> may be polypropylene fibers. In an embodiment, the nonwoven layer <NUM> may include natural fibers, such as cotton.

In an embodiment, the formed film layer <NUM> is attached to the nonwoven layer <NUM> at bond sites <NUM> where the first side <NUM> of the nonwoven layer <NUM> contacts the land areas <NUM> of the second surface <NUM> of the formed film layer <NUM>. In an embodiment, the fibers <NUM> at the bond sites <NUM> are embedded into the land areas <NUM> of the formed film layer <NUM>, which may be accomplished by a vacuum formed lamination process, as described in further detail below. The bond sites <NUM> are contemplated to be distributed in a pattern, commensurate with some or all of the land areas <NUM>.

<FIG> is an enlarged photograph of one side of a fluid distribution material <NUM> in accordance with an embodiment of the invention, which may be used as the fluid distribution material <NUM> of <FIG>. As illustrated, the fluid distribution material <NUM> includes a formed film layer <NUM> and a nonwoven layer <NUM> on top of the formed film layer <NUM>. The formed film layer <NUM> includes apertures <NUM> and land areas <NUM> extending between the apertures <NUM>. The nonwoven layer <NUM> includes a plurality of continuous fibers <NUM> that extend across the land areas <NUM> and the apertures <NUM> of the formed film layer <NUM>. The continuous fibers <NUM> are attached to the land areas <NUM> at bond sites <NUM>.

A closer view of the apertures <NUM>, land areas <NUM>, and bond sites <NUM> is illustrated in <FIG>.

<FIG> is an enlarged photograph of a partial cross-sectional view of the fluid distribution material <NUM> of <FIG> with the formed film layer <NUM> on top of the nonwoven layer <NUM>. <FIG> also shows a plurality of apertured protuberances <NUM> with land areas <NUM> extending in between adjacent apertured protuberances <NUM>. The apertured protuberances <NUM> (<FIG>) and corresponding apertures <NUM> (<FIG> and <FIG>) are arranged in a <NUM> mesh pattern, and each of the apertures <NUM> has a hexagonal ("hex") shape, as represented by the dashed white lines in <FIG>.

<FIG> is an enlarged photograph of one side of a fluid distribution material <NUM> in accordance with an embodiment of the invention, which may be used as the fluid distribution material <NUM> of <FIG>. As illustrated, the fluid distribution material <NUM> includes a formed film layer <NUM> and a nonwoven layer <NUM> on top of the formed film layer <NUM>. The formed film layer <NUM> includes three different types of apertures 626A, 626B, 626C, and land areas <NUM> extending between the apertures 626A, 626B, 626C. As illustrated, the apertures 626A, 626B, 626C are arranged in a pattern that resembles a blossom or flower, with a center, substantially-round aperture 626A being surrounded by four smaller, substantially-round apertures 626B and four elliptical or oval-shaped apertures 626C, each having their major axis extending at approximately <NUM> degree angles relative to an x-y grid. The circular apertures 626A, 626B may have a mesh count of about <NUM> apertures per linear <NUM> corresponding to <NUM> inch (i.e., <NUM> mesh) in the x direction and the y direction. The nonwoven layer <NUM> includes a plurality of continuous fibers <NUM> that extend across the land areas <NUM> and the apertures 626A, 626B, 626C of the formed film layer <NUM>. The continuous fibers <NUM> are attached to the land areas <NUM> at bond sites <NUM>.

A closer view of the apertures 626B, 626C, land areas <NUM>, and bond sites <NUM> is illustrated in <FIG>.

<FIG> is an enlarged photograph of a partial cross-sectional view of the fluid distribution material <NUM> of <FIG> with the formed film layer <NUM> on top of the nonwoven layer <NUM>. <FIG> also shows a plurality of apertured protuberances <NUM> with land areas <NUM> extending in between adjacent apertured protuberances <NUM>.

<FIG> schematically illustrates an apparatus <NUM> that may be used to manufacture the fluid distribution materials of embodiments of the invention described herein. As illustrated, an extrusion die <NUM> extrudes polymer melt curtain <NUM> onto a forming structure <NUM> that rotates about a cylinder <NUM> that has a vacuum slot <NUM> through which a vacuum is pulled. The polymer melt curtain <NUM> may include, for example, one or more polyolefin materials and a surfactant, as well as one or more additives, such as a colorant. A nonwoven web <NUM> is unwound from a roll <NUM> over a laminating roller <NUM> and directed to the melt curtain <NUM> while the melt curtain <NUM> is still molten at an impingement point <NUM> between the rotating forming structure <NUM> and the laminating roller <NUM>.

The fibers of the nonwoven web <NUM> adjacent to the melt curtain <NUM> embed in the surface of the melt curtain <NUM> as the two layers cross over the vacuum slot <NUM> together, where the apertured protuberances are formed in the polymer web (i.e., the solidified melt curtain <NUM>) in substantially the same pattern that is provided by the forming structure <NUM>. As the polymer web (which solidifies to form, for example, the formed film layer <NUM> of <FIG>) is apertured, air flow is initiated through the apertured protuberances (e.g., <NUM>) which cools and solidifies the apertured protuberances (e.g., <NUM>). The polymer web is also cooled by the forming structure <NUM> as the fibers (e.g., <NUM>) of the nonwoven are embedded in the land areas (e.g., <NUM>) between the apertured protuberances (e.g., <NUM>) so that the nonwoven is bonded to the formed film layer (e.g., <NUM>) at the land areas (e.g., <NUM>). The resulting vacuum formed laminate <NUM> is pulled off of forming structure <NUM> by a peel roller <NUM> and travels to one or more subsequent rollers <NUM> until it may be wound by a winder <NUM> into a roll <NUM>. Additional rollers and/or other pieces of equipment may be used in the apparatus <NUM>.

The illustrated embodiment is not intended to be limiting in any way. For example, in an embodiment, the apparatus <NUM> may also include additional equipment, such as intermeshing gears that may be used to activate the fluid distribution material in the machine direction or the transverse direction, if desired. Other equipment that may be included in the apparatus <NUM> include, but are not limited to, corona treatment apparatus, printers, festooning equipment, spooling equipment, and additional processing equipment that may emboss or provide additional apertures to the vacuum formed laminate <NUM>.

<FIG> schematically illustrate how the fluid distribution material <NUM> handles a fluid insult <NUM> and distributes the fluid insult <NUM> to a substrate <NUM> located beneath the fluid distribution material <NUM>, which may be an absorbent core, as described above, or may be a blotter paper used during testing, as described below. Although a topsheet may be positioned above the fluid distribution material <NUM>, as described above, a topsheet is not illustrated in <FIG> for simplicity.

As illustrated in <FIG>, the fluid insult <NUM>, which is schematically represented as a plurality of droplets, is introduced to the formed film layer <NUM> side of the fluid distribution material <NUM>. <FIG> illustrates the initial phase of fluid strikethrough. Portions of the insult <NUM> are able to enter the unobstructed apertured protuberances <NUM> and pass through to the nonwoven layer <NUM>, while other portions of the insult <NUM> are trapped on the land areas <NUM> between the apertured protuberances <NUM>. As the initial fluid that entered the apertured protuberances <NUM> drains into and spreads along the nonwoven layer <NUM>, and even passes through to the substrate <NUM> below, the fluid in between the apertured protuberances <NUM> is siphoned into the apertured protuberances <NUM>, due to the surface tension of the fluid and the hydrophilic nature of the formed film layer <NUM>, until all or substantially all of the fluid passes through the formed film layer <NUM> of the fluid distribution material <NUM>, as illustrated in <FIG> and <FIG>. Although it is desirable to have the nonwoven layer <NUM> to also be hydrophilic, the nonwoven layer <NUM> may in some embodiments be hydrophobic.

A series of fluid distribution materials were created using the apparatus <NUM> described above. A hydrophilic spunbond nonwoven, manufactured by Fitesa of Simpsonville, South Carolina, comprising a plurality of polypropylene fibers and having a nominal basis weight of <NUM> grams per square meter (gsm) was used as the nonwoven web <NUM>. A blend of low density polyethylene, high density polyethylene, titanium dioxide and surfactant was extruded through the extrusion die <NUM> to create the melt curtain <NUM>, which was cast onto different forming structures <NUM> as the nonwoven web <NUM> was fed into the impingement point <NUM> to create laminates <NUM> with formed film layers having different patterns of apertured protuberances and open areas. The formed film layers had a basis weight of about <NUM> gsm so that the laminates <NUM> had a total basis weight of about <NUM> gsm.

The open area, which is the percent area of the openings through the sample as compared to the total area of the sample, for each sample was measured using a computerized video device that includes a video camera, a microscope using a 24x magnification, and imaging software that measures contrast. A magnified image was taken of the sample when looking at the formed film layer side of the sample, and the video camera, which can discern the openings through the sample from solid portions of the sample via contrast, digitized the data to calculate the percent open area. Table I summarizes the laminated ("laminate") samples that were created, along with the respective open areas that were measured.

<FIG> (described above) illustrate a portion of Sample <NUM> and <FIG> (described above) illustrate a portion of Sample <NUM>. As noted above, "mesh" refers to the number of apertures per linear <NUM> corresponding to <NUM> inch, "hexagonal" refers to the shape of the apertures, and "blossom" refers to the pattern illustrated in <FIG> that has different sized and shaped apertures that are arranged in a blossom or flower pattern.

The same blend of materials and forming structures that were used to create the formed film layers for Samples <NUM>-<NUM> were used to create only apertured formed films having a basis weight of about <NUM> gsm, which is the same basis weight of the formed film layers of Samples <NUM>-<NUM>. The open area for each film (absent the nonwoven web <NUM>) was measured under a microscope using a 24x magnification and imaging software that measures contrast. Each of the film samples was placed on top of (but not bonded in any way to) the same spunbond nonwoven web <NUM> that was used to create the laminates for Samples <NUM>-<NUM> (i.e., a <NUM> gsm spunbond polypropylene nonwoven web manufactured by Fitesa of Simpsonville, South Carolina), with the apertured protuberances extending in a direction away from the nonwoven web to form "stacks" of formed films and nonwoven webs. Table II summarizes the comparative stack ("stack") samples that were created, along with the respective open areas that were measured in the same manner as the open areas of the laminate samples, with the formed film side of the stack facing the video camera.

Each of the stack samples had an open area lower than the open area of a laminate sample having the same apertured protuberance pattern, which indicates that the fibers in the nonwoven layers of the laminate samples may have spread apart at the locations of the apertured protuberances to provide a higher open area. Without being bound by theory (and returning to <FIG>), it is postulated that during the vacuum forming lamination process, air being pulled through the nonwoven layer <NUM> and the formed film layer <NUM> may cause the fibers <NUM> located adjacent the proximal apertures <NUM> to separate and gather at a higher density at the land areas <NUM> where there is no air flow as the polymer in the formed film layer <NUM> cools on the forming structure. When the polymer in the formed film layer <NUM> solidifies, the fibers <NUM> of the nonwoven layer <NUM> are essentially locked in place at the bond sites <NUM> while the fibers <NUM> located adjacent the proximal apertures <NUM> remain spread apart.

All samples were tested for suitability for use as a fluid distribution material in accordance with embodiments of the invention. Specifically, for each sample, strikethrough time and rewet, which is a measure of dryness, were determined for three different test specimens by a "Lister AC" fluid testing device, by Lenzing Technik GmbH & Co KG, Austria. The procedures for measuring strikethrough time ("Strikethrough Test Method") and rewet ("Rewet Test Method"), which are based on the principles outlined in EDANA test methods ERT <NUM>-<NUM> and ERT <NUM>-<NUM>, respectively, will now be described. All of the test specimens and absorbent substrates, filter papers and pickup papers described below were conditioned at <NUM> ± <NUM> at <NUM>% ±<NUM>% relative humidity for <NUM> hours.

For the Strikethrough Test Method, each test specimen was cut into a <NUM>" x <NUM>" (<NUM> x <NUM>) piece and placed over an absorbent substrate in the form of a stack of three (<NUM>) pieces of <NUM>" x <NUM>" filter (blotter) paper. The test specimen was oriented so that the formed film layer faced upward and the nonwoven layer was in contact with the filter paper. A <NUM> strikethrough plate with a <NUM> x <NUM> base dimension and an orifice with electrodes extending into the orifice was placed on top of the test specimen. A <NUM> sample of fluid that simulates urine and consists of a solution of <NUM>/l of analytical grade sodium chloride in deionized water, with a surface tension of <NUM> ± <NUM> mN/m at <NUM> ± <NUM>, was dispersed into the orifice from a height of <NUM> above the surface of the test specimen. The fluid completed a circuit with the electrodes, which started a timer. When the fluid was completely struck through the orifice, the circuit was broken and the timer stopped, thereby registering the elapsed time or "strikethrough time" in seconds.

For the "Rewet Test Method," after the initial insult from the Strikethrough Test Method, an additional insult was dispensed to the center of the test specimen with the strikethrough plate still in place. The additional insult was based on the total insult (including the initial <NUM> insult from the Strikethrough Test Method) needed to fully saturate the underlying absorbent substrate and was calculated by multiplying the weight of the stack of three pieces of filter paper (when dry) by the load factor of the filter paper, and was determined to be <NUM>. The strikethrough plate was removed and a <NUM> rewet weight with a <NUM> x <NUM> footing was placed on top of the test specimen to allow the fluid to thoroughly spread out into the absorbent substrate. Two pre-weighed <NUM>" x <NUM>" pick up (blotter) papers were pressed against the surface of the test specimen with the rewet weight to create a pressure of about <NUM> kPa corresponding to <NUM> psi, to simulate a toddler sitting on a diaper, for an additional two minutes. The wetted pickup papers were weighed. Any residual wetness in the test specimen is transferred to the pickup papers, and the difference between the pre-measured dry weight of the pickup papers and the wetted weight of the pickup papers is the "rewet value" in grams. The average strikethrough time and rewet value test results for three test specimens for each sample are listed in below in Table III.

The strikethrough time and rewet results are also plotted in <FIG> and <FIG>, respectively. As shown in <FIG>, all of the laminate samples with hexagonal shaped apertures ("hex") had faster strikethrough times as compared to their corresponding stack samples. The laminate sample with the blossom pattern (Sample <NUM>) had a slightly slower strikethrough time than its corresponding stack sample (Sample <NUM>). As shown in <FIG>, all of the laminate samples (Samples <NUM>-<NUM>) had at least <NUM>% lower rewet values than their corresponding stack samples (Samples <NUM>-<NUM>), and each of the laminate samples (Samples <NUM>-<NUM>) had rewet values of less than <NUM>, while each of the stack samples (Samples <NUM>-<NUM>) had rewet values greater than <NUM>.

All samples were also tested for thickness when under pressure so that the compressibility of the samples could be determined. Thicknesses were measured using a Testing Machines, Inc. Model <NUM>-<NUM> motorized low-load micrometer with an anvil having a diameter of <NUM> corresponding to <NUM> inches, a dead weight load of <NUM> grams (<NUM> pounds), which is equivalent to an applied pressure of <NUM> kPa corresponding to <NUM> psi, and a dwell time of <NUM>-<NUM> seconds. Multiple measurements were made for each sample at different locations across the sample, and the measurements for each sample were averaged to determine a baseline thickness measurement for each sample. Additional weight was added to the anvil to increase the applied pressure to <NUM> kPa, <NUM> kPa, <NUM> kPa, and <NUM> kPa, corresponding to <NUM> psi, <NUM> psi, <NUM> psi and <NUM> psi, respectively, <NUM> kPa corresponding to <NUM> psi is commonly likened to the pressure exerted by a toddler sitting on a diaper. Multiple measurements were made for each sample at different locations across the sample at each pressure, and the measurements for each sample at each pressure were averaged. The results of the thickness testing under different applied pressures are listed in Table IV below.

The results of the thickness testing under different pressures were used to calculate the compressibility of the samples a various pressures, using the thickness measurement at the lowest pressure (i.e., <NUM> kPa corresponding to <NUM> psi) as the baseline. The compressibility of each sample was calculated for each of the <NUM> kPa, <NUM> kPa, and <NUM> kPa, corresponding to <NUM> psi, <NUM> psi, <NUM> psi, and <NUM> psi, respectively, applied pressures using the following equation (<NUM>): <MAT> where x is the applied pressure, thicknessx psi is the average thickness at the applied pressure, and thickness<NUM> psi is the average thickness at <NUM> kPa corresponding to <NUM> psi applied pressure. The results are listed in the following Table V.

The compressibility test results are also illustrated in <FIG>, with the baseline applied pressure (i.e. <NUM> kPa corresponding to <NUM> psi) set to <NUM>% for all samples. Specifically, <FIG> illustrates the results for Sample <NUM> (laminate) and Sample <NUM> (stack), which each had a formed film layer with apertured protuberances in the <NUM> mesh hexagonal ("hex") pattern. <FIG> illustrates the results for Sample <NUM> (laminate) and Sample <NUM> (stack), which each had a formed film layer with apertured protuberances in the <NUM> mesh hexagonal ("hex") pattern. <FIG> illustrates the results for Sample <NUM> (laminate) and Sample <NUM> (stack), which each had a formed film layer with apertured protuberances in the <NUM> mesh hexagonal ("hex") pattern. <FIG> illustrates the results for Sample <NUM> (laminate) and Sample <NUM> (stack), which each had a formed film layer with apertured protuberances in the <NUM> mesh blossom pattern.

Linear trendlines were generated for each set of data and included in the Figures. Table VI lists the slopes, intercepts, and R<NUM> values for the associated trendline for each sample.

<FIG> and the linear trendlines indicate that for each of the apertured protuberance patterns, the laminates tend to have flatter slopes than the stacks, which provides an indication that the laminates do not compress as much as the stacks as the applied pressure is increased, especially for the <NUM> mesh hexagonal and <NUM> mesh blossom patterns. Without being bound by theory, it is postulated that for the laminates, the fibers of the nonwoven that are embedded in the lands of the apertured formed film provide a scaffolding structure that allows the apertured protuberances to better maintain their shape and not compress as much as apertured protuberances that do not have such a benefit. Such a benefit may provide a particular advantage so that the fluid distribution material performs well under the applied pressures experienced while being worn by a user.

Embodiments of the invention provide a fluid distribution material that reduces residual wetness, even after the absorbent article is subjected to pressure. The combination of the formed film layer, which has a lower basis weight compared to known film-only acquisition distribution materials, and the nonwoven layer laminated to the formed film layer may provide a modulus that is sufficient to allow the fluid distribution material to be converted into an absorbent article, as desired.

Claim 1:
A fluid distribution material (<NUM>) for use in an absorbent article (<NUM>), the fluid distribution material comprising:
a formed film layer (<NUM>) which comprises one or more polyolefins, the formed film layer (<NUM>) having a user-facing side and a garment-facing side opposite the user-facing side, the formed film layer comprising a plurality of apertured protuberances (<NUM>) arranged in a pattern having <NUM> to <NUM> protuberances per linear <NUM> corresponding to <NUM> inch, each of the protuberances comprising a continuous sidewall (<NUM>) extending from the user-facing side, the garment-facing side having a plurality of apertures (<NUM>) aligned with the plurality of apertured protuberances and land areas (<NUM>) in between the apertures, the formed film layer having a basis weight of between about <NUM> gsm and about <NUM> gsm; and
a nonwoven layer (<NUM>) laminated to the garment-facing side of the formed film layer, the nonwoven layer comprising a plurality of fibers (<NUM>) attached to the formed film layer at the land areas, the nonwoven layer having a basis weight of between about <NUM> gsm and about <NUM> gsm,
wherein the fluid distribution material has a rewet value of less than <NUM> grams in accordance with the Rewet Test Method, and
wherein the fluid distribution material has a compressibility of less than <NUM>% between pressures of <NUM> kPa and <NUM> kPa, corresponding to <NUM> psi and <NUM> psi, respectively.