Three-dimensional, slitted substrate material for an absorbent article

Abstract

Described is an absorbent article that includes a substrate comprising a plurality of openings formed when the substrate is provided with a plurality of discrete slits and subsequently stretched in a stretch direction to a stretched position and an adjacent material attached to the substrate when in the stretched position, wherein the substrate comprises a plurality of normalized absolute height difference values in the stretched position, and wherein at least 75% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.4.

Description

PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545THREE-DIMENSIONAL, SLITTED SUBSTRATE MATERIAL FOR AN ABSORBENT ARTICLEFIELD OF THE INVENTION

[0001] The present disclosure relates generally to absorbent articles intended for personal wear, and more particularly to absorbent articles with a three-dimensional, slitted substrate material.BACKGROUND

[0002] Two primary functions of personal care absorbent articles such as diapers, adult incontinence garments, or menstrual pads are to absorb and retain body exudates such as urine, fecal material, blood, and menses with low leakage of the exudates from the absorbent article and to provide healthy, dry skin and a dry feel to the wearer of the absorbent article. To enable leakage protection and skin dryness, it is essential that the absorbent article allows for rapid passage of the body exudates into an absorbent structure of the absorbent article. Should the absorbent article not allow for rapid fluid penetration and subsequent fluid retention, such a situation could result in overhydration of the skin, rendering it susceptible to irritation and infection.SUMMARY

[0003] The terms “invention,” “the invention,” “this invention” and “the present invention” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various embodiments of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings, and each claim.

[0004] According to some embodiments, an absorbent article includes a substrate comprising a plurality of openings formed when the substrate is provided with a plurality of discrete slits andUS2008 31858231 6PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 subsequently stretched in a stretch direction to a stretched position and an adjacent material attached to the substrate when in the stretched position, wherein the substrate comprises a plurality of normalized absolute height difference values in the stretched position, and wherein at least 75% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.4.

[0005] According to various embodiments, a method of making an absorbent article includes providing a substrate, creating a plurality of discrete slits in the substrate, thereafter stretching the substrate to a stretched position to provide a stretched substrate in which the plurality of discrete slits forms a plurality of openings in the stretched substrate in the stretched position, and thereafter attaching the stretched substrate in the stretched position to an adjacent material to form at least part of the absorbent article, wherein the stretched substrate comprises a plurality of normalized absolute height difference values, and wherein at least 75% of the normalized absolute height difference values of the stretched substrate are less than 0.4.

[0006] According to various embodiments, an absorbent article includes, an outer cover, a bodyside composite, and an absorbent body disposed between the outer cover and the bodyside composite, wherein the body side composite comprises a surge layer and an adjacent layer attached to the surge layer, wherein the surge layer is formed of a substrate comprising a plurality of openings formed when the substrate is provided with a plurality of discrete slits and subsequently stretched in a stretch direction to a stretched position, wherein the substrate comprises a plurality of normalized absolute height difference values in the stretched position and wherein at least 75% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.4

[0007] Various implementations described in the present disclosure can include additional systems, methods, features, and advantages, which cannot necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure. Corresponding features and components throughout the figures can be designated by matching reference characters for the sake of consistency and clarity.

[0009] FIG. 1 is side perspective view of an exemplary embodiment of an absorbent article, such as a diaper, in a fastened condition.

[0010] FIG. 2 is a front perspective cross-sectional view of the absorbent article of FIG. 1, with the absorbent article being in a relaxed configuration.

[0011] FIG. 3 is a front perspective cross-sectional view of another exemplary embodiment of an absorbent article, such as a diaper.

[0012] FIG. 4A is a top view of an embodiment of a slitted substrate material.

[0013] FIG. 4B is a top view of the slitted substrate material of FIG. 4A in a stretched position.

[0014] FIG. 5A is a top view of another embodiment of a slitted substrate material.

[0015] FIG. 5B is a top view of the slitted substrate material of FIG. 5 A in a stretched position.

[0016] FIG. 6A is a top view of another embodiment of a slitted substrate material.

[0017] FIG. 6B is a top view of the slitted substrate material of FIG. 6A in a stretched position.

[0018] FIG. 7 is a flow chart of a method of calculating NAHD values.

[0019] FIGS. 8A-8C are colored 3D scans of the slitted substrate material of FIG. 4A stretched to different stretched positions, and FIGS. 8D-8F are greyscale 3D scans of the slitted substrate material of FIG. 4A stretched to different stretched positions.

[0020] FIGS. 9A-9C are colored 3D scans of the slitted substrate material of FIG. 5A stretched to different stretched positions, and FIGS. 9D-9F are greyscale 3D scans of the slitted substrate material of FIG. 5 A stretched to different stretched positions.

[0021] FIG. 10A is a 3D scan of the stretched slitted substrate material of FIG. 6B, and FIG. 10B is a greyscale 3D scan of the stretched slitted substrate material of FIG. 6B.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545

[0022] FIG. 11 shows the plotted absolute height difference distributions for the 3D scans of FIGS. 8-10.

[0023] FIG. 12 shows the plotted normalized absolute height difference distributions for the 3D scans of FIGS. 8-10.

[0024] FIG. 13 is a schematic illustration of embodiments of the stretched slitted substrate material disclosed herein provided as an internal surge layer in an absorbent article.

[0025] FIG. 14 is a schematic illustration of embodiments of the stretched slitted substrate material disclosed herein provided as a topical surge layer in an absorbent article.DETAILED DESCRIPTION

[0026] Described herein is an absorbent material that is cut with slits of a kirigami pattern and subsequently stretched. Stretching the slitted material provides increased void volume and fluid intake. However, stretching the slitted material also provides Z-direction deformation of the slitted material. This Z-direction deformation may affect a consumer’s perception of softness of the stretched, slitted material. Surprisingly, neither a measured surface roughness nor a measured absolute height difference was found to correlate to the consumer perception of softness. Rather, a new parameter, a normalized absolute height difference, was developed to identify a correlation between the measured Z-direction deformation and consumer perception of softness. The normalized absolute height difference parameter may be used to define what slit patterns and amounts of stretch will result in a balance of intake performance and softness. Various other benefits and advantages may be realized with the systems and methods provided herein, and the aforementioned advantages should not be considered limiting.

[0027] Definitions:

[0028] The terms “absorbent article” and “disposable absorbent article” refer herein to an article which may be placed against or in proximity to the body (i.e., contiguous with the body) of the wearer to absorb and contain various liquid, solid, and semi-solid exudates discharged from the body. Such absorbent articles, as described herein, are intended to be discarded after a limited period of use instead of being laundered or otherwise restored for reuse. It is to be understood that the present disclosure is applicable to various disposable absorbent articles, including, but notPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 limited to, diapers, diaper pants, training pants, youth pants, swim pants, feminine hygiene products, including, but not limited to, menstrual pads or pants, incontinence products and other adult care garments, medical garments, surgical pads and bandages, other personal care or health care garments, and the like without departing from the scope of the present disclosure.

[0029] The term “acquisition layer” refers herein to a layer capable of accepting and temporarily holding liquid body exudates to decelerate and diffuse a surge or gush of the liquid body exudates and to subsequently release the liquid body exudates therefrom into another layer or layers of the absorbent article.

[0030] The term “bonded” or “coupled” refers herein to the joining, adhering, connecting, attaching, or the like, of two elements. Two elements will be considered bonded or coupled together when they are joined, adhered, connected, attached, or the like, directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements. The bonding or coupling of one element to another can occur via continuous or intermittent bonds.

[0031] The term “carded web” refers herein to a web containing natural or synthetic staple length fibers typically having fiber lengths less than 100 mm. Bales of staple fibers can undergo an opening process to separate the fibers which are then sent to a carding process which separates and combs the fibers to align them in the machine direction after which the fibers are deposited onto a moving wire for further processing. Such webs are usually subjected to some type of bonding process such as thermal bonding using heat and / or pressure. In addition to or in lieu thereof, the fibers may be subject to adhesive processes to bind the fibers together such as by the use of powder adhesives. The carded web may be subjected to fluid entangling, such as hydroentangling, to further intertwine the fibers and thereby improve the integrity of the carded web. Carded webs, due to the fiber alignment in the machine direction, once bonded, will typically have more machine direction strength than cross machine direction strength.

[0032] "Elastomeric" refers to a material or composite which can be elongated by at least 50 percent of its relaxed length and which will recover, upon release of the applied force, at least 20 percent of its elongation. It is generally preferred that the elastomeric material or composite be capable of being elongated by at least 50 percent, more preferably by at least 100 percent, and stillPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 more preferably by at least 300 percent of its relaxed length and recover, upon release of an applied force, at least 50 percent of its elongation.

[0033] The term “film” refers herein to a thermoplastic film made using an extrusion and / or forming process, such as a cast film or blown film extrusion process. The term includes apertured films, slit films, and other porous films which constitute liquid transfer films, as well as films which do not transfer fluids, such as, but not limited to, barrier films, filled films, breathable films, and oriented films.

[0034] The term “gsm” refers herein to grams per square meter.

[0035] The term “hydrophilic” refers herein to fibers or the surfaces of fibers which are wetted by aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and materials involved. Equipment and techniques suitable for measuring the wettability of particular fiber materials or blends of fiber materials can be provided by Cahn SFA-222 Surface Force Analyzer System, or a substantially equivalent system. When measured with this system, fibers having contact angles less than 90 are designated “wettable” or hydrophilic, and fibers having contact angles greater than 90 are designated “nonwettable” or hydrophobic.

[0036] The term “liquid impermeable” refers herein to a layer or multi-layer laminate in which liquid body exudates, such as urine, will not pass through the layer or laminate, under ordinary use conditions, in a direction generally perpendicular to the plane of the layer or laminate at the point of liquid contact.

[0037] The term “liquid permeable” refers herein to any material that is not liquid impermeable.

[0038] The term “meltblown” refers herein to fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity heated gas (e.g., air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which can be a microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. Such a process is disclosed, for example, in U.S. Patent No. 3,849,241 to Butin et al., which is incorporated herein by reference.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545Meltblown fibers are microfibers which may be continuous or discontinuous, are generally smaller than 0.6 denier, and may be tacky and self-bonding when deposited onto a collecting surface.

[0039] The term “nonwoven” refers herein to materials and webs of material which are formed without the aid of a textile weaving or knitting process. The materials and webs of materials can have a structure of individual fibers, filaments, or threads (collectively referred to as “fibers”) which can be interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven materials or webs can be formed from many processes such as, but not limited to, meltblowing processes, spunbonding processes, carded web processes, etc.

[0040] The term “pliable” refers herein to materials which are compliant and which will readily conform to the general shape and contours of the wearer’s body.

[0041] The term “spunbond” refers herein to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine capillaries of a spinnerette having a circular or other configuration, with the diameter of the extruded filaments then being rapidly reduced by a conventional process such as, for example, eductive drawing, and processes that are described in U.S. Patent No. 4,340,563 to Appel et al., U.S. Patent No. 3,692,618 to Dorschner et al., U.S. Patent No. 3,802,817 to Matsuki et al., U.S. Patent Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Patent No. 3,502,763 to Hartmann, U.S. Patent No. 3,502,538 to Peterson, and U.S. Patent No. 3,542,615 to Dobo et al., each of which is incorporated herein in its entirety by reference. Spunbond fibers are generally continuous and often have average deniers larger than 0.3, and in an embodiment, between 0.6, 5 and 10 and 15, 20 and 40. Spunbond fibers are generally not tacky when they are deposited on a collecting surface.

[0042] The term “superabsorbent” refers herein to a water-swellable, water-insoluble organic or inorganic material capable, under the most favorable conditions, of absorbing at least 15 times its weight and, in an embodiment, at least 30 times its weight, in an aqueous solution containing 0.9 weight percent sodium chloride. The superabsorbent materials can be natural, synthetic and modified natural polymers and materials. In addition, the superabsorbent materials can be inorganic materials, such as silica gels, or organic compounds, such as cross-linked polymers.

[0043] The term “super-majority” refers herein to a majority of at least 65%.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545

[0044] The term “thermoplastic” refers herein to a material which softens and which can be shaped when exposed to heat and which substantially returns to a non-softened condition when cooled.

[0045] The term “wearer,” “user,” or “caregiver” refers herein to one who fits an absorbent article, such as, but not limited to, a diaper, diaper pant, training pant, youth pant, incontinent product, or other absorbent article about the wearer of one of these absorbent articles. A user and a wearer can be one and the same person.

[0046] Absorbent Article:

[0047] Referring to FIGS. 1-2, a non-limiting illustration of an absorbent article 10, for example a diaper, is illustrated. While the embodiments and illustrations described herein may generally apply to absorbent articles manufactured in the product longitudinal direction, which is hereinafter called the machine direction manufacturing of a product, it should be noted that one of ordinary skill in the art could apply the information herein to absorbent articles manufactured in the latitudinal direction of the product, which hereinafter is called the cross-machine direction manufacturing of a product, without departing from the spirit and scope of the disclosure.

[0048] Turning to the construction of the articles of the present disclosure, absorbent article 10 illustrated in FIGS. 1-2 can include a chassis 11. The absorbent article 10 can include a front waist region 12, a rear waist region 14, and a crotch region 16 disposed between the front waist region 12 and the rear waist region 14 and interconnecting the front and rear waist regions 12, 14, respectively. The absorbent article 10 can have a pair of longitudinal side edges 18, 20 and a pair of opposite waist edges, respectively designated front waist edge 22 and rear waist edge 24. The front waist region 12 can be contiguous with the front waist edge 22 and the rear waist region 14 can be contiguous with the rear waist edge 24. Portions of the longitudinal side edges 18, 20 in the crotch region 16 can generally define leg openings for the legs of the wearer when the absorbent article 10 is worn.

[0049] The absorbent article 10 can include an outer cover 26 and a bodyside liner 28. The outer cover 26 and the body side liner 28 can form a portion of the chassis 11. In some embodiments, the bodyside liner 28 can be bonded to the outer cover 26 in a superposed relation by any suitable means such as, but not limited to, adhesives, ultrasonic bonds, thermal bonds, pressure bonds, or other conventional techniques. The outer cover 26 can define a length in the longitudinal direction,PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 and a width in a lateral direction, which, in the illustrated embodiment, can coincide with the length and width of the absorbent article 10.

[0050] The chassis 11 can include an absorbent system 34. The absorbent system 34 can be disposed between the outer cover 26 and the bodyside liner 28. In certain embodiments, the absorbent system 34 can have a length and width that are the same as or less than the length and width of the absorbent article 10. The bodyside liner 28, the outer cover 26, and the absorbent system 34 can form part of an absorbent assembly 44. The absorbent assembly 44 can also include a fluid transfer layer 46 and a fluid acquisition layer 43 between the bodyside liner 28 and the fluid transfer layer 46 as is known in the art. Such a fluid transfer layer 46 is sometimes alternatively known as a corewrap. The fluid acquisition layer 43 is sometimes alternatively known as a surge layer. In some embodiments, the fluid acquisition layer 43 may replace the bodyside liner 28 as the layer closest to the skin. The absorbent assembly 44 can also include a spacer layer 48 disposed between the absorbent system 34 and the outer cover 26. Still further embodiments of the absorbent assembly 44 are contemplated. For example, the absorbent assembly 44 may include a further corewrap material disposed opposite the fluid transfer layer 46 and between the absorbent system 34 and the space layer 48. The spacer layer 48 may be present in some of these embodiments and absent in other embodiments.

[0051] Outer cover:

[0052] The outer cover 26 and / or portions thereof can be one or more layers of breathable and / or liquid impermeable film. The outer cover 26 and / or portions thereof can be elastic, stretchable, or non-stretchable. The outer cover 26 may be constructed of a single layer, multiple layers, laminates, spunbond fabrics, films, meltblown fabrics, elastic netting, microporous webs, bonded- carded webs or foams provided by elastomeric or polymeric materials. In an embodiment, for example, the outer cover 26 can be constructed of a microporous polymeric film, such as polyethylene or polypropylene. The outer layer may also be constructed of the same materials from which the bodyside liner 28 can be constructed as described herein.

[0053] Bodyside liner:

[0054] The bodyside liner 28 of the absorbent article 10 can overlay the absorbent system 34 and the outer cover 26 and can isolate the wearer’s skin from liquid waste retained by the absorbentPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 system 34. In various embodiments, a fluid transfer layer 46 can be positioned between the bodyside liner 28 and the absorbent system 34. In various embodiments, a fluid acquisition layer 43 can be positioned between the bodyside liner 28 and the absorbent system 34 or fluid transfer layer 46 (if present). In various embodiments, the bodyside liner 28 can be bonded to the fluid acquisition layer 43 or to the fluid transfer layer 46 (if no fluid acquisition layer 43 is present) via adhesive and / or by a point fusion bonding. The point fusion bonding may be selected from ultrasonic, thermal, pressure bonding, and combinations thereof.

[0055] In an embodiment, the bodyside liner 28 can extend beyond the absorbent system 34 and / or a fluid transfer layer 46 (if present) and / or a fluid acquisition layer 43 (if present) and / or a spacer layer 48 (if present) to overlay a portion of the outer cover 26 and can be bonded thereto by any method deemed suitable, such as, for example, by being bonded thereto by adhesive, to substantially enclose the absorbent system 34 between the outer cover 26 and the bodyside liner 28. The body side liner 28 can be suitably compliant, soft feeling, and non-irritating to the wearer’ s skin and can be the same as or less hydrophilic than the absorbent system 34 to permit body exudates to readily penetrate through to the absorbent system 34 and provide a relatively dry surface to the wearer.

[0056] The bodyside liner 28 can be manufactured from one or more layers of a wide selection of materials, such as synthetic fibers (for example, polyester or polypropylene fibers), natural fibers (for example, wood or cotton fibers), a combination of natural and synthetic fibers, woven fabrics, non-woven fabrics, porous foams, reticulated foams, polymer films, apertured plastic films, or the like. Examples of suitable materials include, but are not limited to, rayon, wood, cotton, polyester, polypropylene, polyethylene, nylon, or other heat-bondable fibers, polyolefins, such as, but not limited to, copolymers of polypropylene and polyethylene, linear low-density polyethylene, and aliphatic esters such as polylactic acid, finely perforated film webs, net materials, and the like, as well as combinations thereof.

[0057] Absorbent Body:

[0058] The absorbent system 34 can be suitably constructed to be generally compressible, conformable, pliable, non-irritating to the wearer’s skin and capable of absorbing and retaining liquid body exudates. The absorbent system 34 can be manufactured in a wide variety of sizes andPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 shapes (for example, rectangular, trapezoidal, T-shape, I-shape, hourglass shape, etc.) and from a wide variety of materials. The size and the absorbent capacity of the absorbent system 34 should be compatible with the size of the intended wearer (infants to adults) and the liquid loading imparted by the intended use of the absorbent article 10. The absorbent system 34 can have a length and width that can be less than or equal to the length and width of the absorbent article 10.

[0059] If a spacer layer 48 is present, the absorbent system 34 can be disposed on the spacer layer 48 and superposed over the outer cover 26. In some embodiments, a spacer layer 48 may not be present and the absorbent system 34 can directly contact the outer cover 26 and can be directly bonded to the outer cover 26. However, it is to be understood that the absorbent system 34 may be in contact with, and not bonded with, the outer cover 26 and remain within the scope of this disclosure. In some embodiments, at least a portion of a layer, such as but not limited to, a fluid transfer layer 46 and / or a spacer layer 48, can be positioned between the absorbent system 34 and the outer cover 26, such as illustrated in FIG. 2. The absorbent system 34 can be bonded to the fluid transfer layer 46 and / or the spacer layer 48. In an embodiment, the absorbent system 34 can be composed of one or more layers of absorbent material, such as fibrous absorbent material and / or superabsorbent material, binder materials, surfactants, selected hydrophobic and hydrophilic materials, pigments, lotions, odor control agents or the like, as well as combinations thereof. In an embodiment, the absorbent system 34 can be a matrix of cellulosic fluff and superabsorbent material. In another embodiment, the absorbent material of the absorbent system 34 can comprise only superabsorbent material. When composed at least partially of superabsorbent materials, such superabsorbent materials can be selected from natural, synthetic, and modified natural polymers and materials. The superabsorbent materials can be inorganic materials, such as silica gels, or organic compounds, such as cross-linked polymers.

[0060] The absorbent article 10 may further include a fluid acquisition layer 43 disposed above the absorbent system 34. For example, the fluid acquisition layer 43 may be disposed between the absorbent system 34 and the bodyside liner 28. Although, in other embodiments, e.g., as may be seen in FIG. 3, the fluid acquisition layer 43 may be a topical material applied to the bodyside liner 28 on the body facing surface 19 of the chassis 11. The fluid acquisition layer 43 may comprise a single layer material or a multi-layer material comprising a fibrous nonwoven web(s). The fluid acquisition layer 43 may be designed to quickly intake liquid and distribute the liquid throughoutPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 the fluid acquisition layer 43. Example nonwoven web(s) include spunbond webs, meltblown webs, and staple fiber webs such as through air bonded carded webs (TABCWs) and hydroentangled webs. Such a fluid acquisition layer 43 may be formed of polymer fibers. The fibers forming the fluid acquisition layer 43 may be synthetic or natural, or they may be layered or blended. The fluid acquisition layer 43 could alternatively be comprised of a film or a foam or a laminate of such materials. In some embodiments, where the fluid acquisition layer 43 is not inherently hydrophilic, the fluid acquisition layer 43 - or the fibers forming the fluid acquisition layer 43 - are treated to be hydrophilic.

[0061] Substrate Material:

[0062] In some embodiments, one or more material layers of the bodyside liner 28, the fluid acquisition layer 43, fluid transfer layer 46, the absorbent system 34, the spacer layer 48, the outer cover 26, and / or any elastomeric layer in the chassis 11 may include a substrate material 50a-50c, e.g., as shown in FIGS. 4A-4B, 5A-5B, and 6A-6B. The substrate material 50a-50c may form an entirety or only a portion of the one or more material layers. However, in certain embodiments, it may be beneficial for the substrate material 50a-50c to be arranged in a topical position, e.g., adjacent to a user’s skin. In some embodiments, the substrate material 50a-50c is provided in the bodyside liner 28 and / or the fluid acquisition layer 43. The substrate material 50a-50c may be formed from any suitable material, including the materials described above with respect to each of the bodyside liner 28, the fluid acquisition layer 43, fluid transfer layer 46, the absorbent system 34, the spacer layer 48, the outer cover 26, and / or the elastomeric layer in the chassis 11.

[0063] The substrate material 50a-50c may include slit patterns, perforation patterns, opening patterns, etc. These patterns may be inspired by kirigami techniques and may have, for example, (i) a semicircle slit pattern (such as the inverted, offset semicircle slit pattern), as shown in FIG. 4A with substrate material 50a, (ii) a wave slit pattern, as shown in FIG. 5A with substrate material 50b, (iii) an arc slit pattern, as shown in FIG. 6A with substrate material 50c, or (iv) any other suitable slit pattern.

[0064] The slitted substrate material 50a-50c may be stretched, e.g., generally stretched in the X- direction, such that the slit patterns create larger openings in the substrate material 50a-50c. For example and with reference to FIGS. 6A and 6B, stretching of substrate material 50c opens the arcPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 shaped slits into arc shaped openings. In some embodiments, the slitted substrate material 50a-50c may be stretched by 5% to 50% in the X-direction; by 15% to 40% in the X-direction; by 25% to 35% in the X-direction; by 5% to 25% in the X-direction; and / or by 10% to 20% in the X-direction. In stretching the slitted substrate material 50a-50c, portions of the slitted substrate material 50a- 50c may undergo deformation in the Z-direction, e.g., the direction perpendicular to the X-Y plane shown in FIGS. 4A-4B, 5A-5B, and 6A-6B.

[0065] Stretching the slitted substrate material 50a-50c to create larger openings in the substrate material 50a-50c may increase the void volume and permeability of the substrate material 50a-50c to facilitate intake of an incoming fluid, e.g., urine, loose feces, menses, etc., into the absorbent article 10 in which the substrate material 50a-50c is incorporated and away from the skin of the wearer. This increase in void volume and permeability of the substrate material 50a-50c may be accomplished without adding extra materials or new layers to the substrate material 50a-50c. Increasing the void volume and permeability of the substrate material 50a-50c by stretching the substrate material 50a-50c may have other benefits including decreasing the amount of material needed to form the substrate material 50a-50c, decreasing the weight of the substrate material 50a- 50c, providing improved flexibility of the substrate material 50a-50c, providing improved breathability of the substrate material 50a-50c, etc.

[0066] However, increasing the void volume and permeability of the substrate material 50a-50c by stretching the slitted substrate material 50a-50c may result in an increase in the deformation of the substrate material 50a-50c in the Z-direction, e.g., toward a user’s skin when the absorbent article 10 is worn. For example, the more that the substrate material 50a-50c is stretched in the X- direction, the greater the deformation of the substrate material 50a-50c may be in the Z-direction, particularly in areas of the substrate material 50a-50c surrounding the slitted areas. This deformation of the substrate material 50a-50c in the Z-direction may be perceived by the user as roughness and a potential cause of skin irritation.

[0067] In some instances, a 3D scanner used for 3D printing, e.g., a CR-Scan Ferret SE 3D Scanner, may be utilized to scan and gather data for the stretched, slitted substrate material 50a- 50c. Data from these scans may be used in calculating various metrics of the stretched, slittedPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 substrate material 50a-50c, e.g., surface roughness, absolute height difference (“AHD”), normalized absolute height difference (“NAHD”), etc.

[0068] In testing various amounts of stretch of the substrate material 50a-50c, it has been unexpectedly found that average surface roughness does not correlate with consumer perception of softness of the stretched, slitted substrate material 50a-50c. Rather and as discussed further below, in some instances a first stretched, slitted substrate material 50a-50c with a measured average surface roughness was perceived as softer by consumers than a second stretched, slitted substrate material 50a-50c with a measured average surface roughness that is essentially equal to that of the first stretched, slitted substrate material 50a-50c.

[0069] The surface roughness (Sa) is computed as a single value that is defined as the average of the height differences of the scanned points of the stretched, slitted substrate material 50a-50c with respect to the average height of the stretched, slitted substrate material 50a-50c. More specifically, a 3D scan is taken of the stretched, slitted substrate material 50a-50c, and a region-of-interest (“ROI”) of the surface of the 3D scan is identified in the 3D scan. When identifying a ROI for a stretched, slitted substrate material 50a-50c that is incorporated in the absorbent article 10, extraneous parts of the absorbent article 10, e.g., leg flaps, waistbands, etc., may be excluded from the ROI. Further, any areas of the stretched, slitted substrate material 50a-50c that are not stretched and slitted may be excluded from the ROI. In some instances, a correction factor may be applied to the ROI of the 3D scan to remove any global tilt in the extracted profile of the ROI.

[0070] From the 3D scan, the single lowest point of the stretched, slitted substrate material 50a- 50c is identified and serves as the benchmark against which the heights of other points of the stretched, slitted substrate material 50a-50c are measured, e g., serves as the zero point for the stretched, slitted substrate material 50a-50c. The heights relative to that lowest point of n points, generally between 10,000 and 30,000 points, within the ROI are measured, wherein each individual height of the n points is designated as an zthsingle scanned point within the ROI. The surface roughness may be calculated using the formula below, where n is the total number of points within the ROI that are measured, hi is the measured height of an zthsingle scanned point (measured relative to the lowest or zero point of the stretched, slitted substrate material 50a-50c), and haveragePCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 is the average or mean height of all the measured heights hi (i.e., the sum of all of the hi divided by / / ):

[0071] Further, it has been unexpectedly found that the absolute height difference (“AHD”) also does not correlate with consumer perception of softness of the stretched, slitted substrate material 50a-50c. The AHD is measured for each ithpoint for the ROI on the stretched, slitted substrate material 50a-50c that is scanned versus the average height of the stretched, slitted substrate material 50a-50c. The average height is calculated as described above. The AHD is calculated for each / "''point scanned using the formula below, where each h is the measured height of an ithpoint scanned relative to the lowest measured point within the ROI, as described above, and h average is the average height:AH D = h, - h average

[0072] Because both surface roughness and AHD surprisingly and unexpectedly did not provide a sufficient correlation with the consumer perception of softness of the stretched, slitted substrate material 50a-50c, it was necessary to determine a value that could be used to correlate consumer perception of softness of the stretched, slitted substrate material 50a-50c.

[0073] It was determined that the normalized absolute height difference (“NAHD”) provided a sufficient correlation with the consumer perception of softness of the stretched, slitted substrate material 50a-50c. The NAHD is calculated for each of the ithpoints scanned for the ROI using the formula below, where max(A / H)) refers to the single maximum AHD of all of the n points measured for the ROI during the scan of the stretched, slitted substrate material 50a-50c (i.e., there will be only one max( HD) within a ROI):PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545

[0074] FIG. 7 shows a flow chart of the method of calculating the NAHD values as described above. At step 1010, a 3D scan of the stretched, slitted substrate material 50a-50c is taken. If the scan is taken after the substrate material is incorporated into an absorbent article (such as a diaper), the absorbent article should be unfolded, opened, and fully stretched and held in place, with the body facing surface exposed for scanning. At step 1020, the height spatial coordinates for each ithpoint of the stretched, slitted substrate material 50a-50c is extracted from the 3D scan and the single lowest point of the stretched, slitted substrate material 50a-50c is identified and serves as the benchmark against which the heights of other points of the stretched, slitted substrate material 50a-50c are measured. At step 1030, a ROI of the surface of the 3D scan of the stretched, slitted substrate material 50a-50c is identified. The ROI may exclude extraneous areas, e.g., leg flap elastics, back panel waistband, etc., of the stretched, slitted substrate material 50a-50c. At step 1040, a correction factor may be applied to the ROI to remove any global tilt in the 3D scan if any tilt is present. At step 1050, the NAHD is calculated for each of the ithpoints scanned for the ROI and a cumulative distribution plot of the NAHD values may be constructed, as described in further detail below with respect to FIG. 12.

[0075] In some embodiments, the slitted and stretched substrate material is incorporated as an internal surge layer provided under a supporting layer (e.g., bodyside liner), as shown in FIG. 13. In other embodiments, the slitted and stretched substrate material is incorporated as atopical surge layer provided as the innermost layer of the absorbent article closest to the wearer, as shown in FIG. 14.

[0076] Softness Test Method:

[0077] Preparation 1 - A 50 gsm topical surge material comprising 50% 2.0 denier polyethylene (“PE”) / polypropylene (“PP”) fibers and 50% 1.35 PE / PP fibers was used as the substrate material in which kirigami patterns were cut and was incorporated into a diaper. This surge material, as would any material being used topically in a diaper, is soft to the touch prior to imparting slitting and stretching. Samples of the topical surge were cut with a wave slit pattern, such as the one shown in FIG. 5A. The slitted surge materials, starting at a length of 178 mm, were then stretched either about 11-12% (to about 200 mm), about 26-27% (to about 227 mm), or about 44-46% (to about 260 mm), such that the slits opened into wave shaped openings (see FIG.5B). It is evidentPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 upon inspection that the extent of Z-deformation increased as the level of stretch increased. The slitted, stretched surge materials were then adhesively bonded to a nonwoven bodyside liner or other nonwoven supporting layer.

[0078] Preparation 2 - The same 50 gsm topical surge material comprising 50% 2.0 denier PE / PP fibers and 50% 1.35 PE / PP fibers as described above in Preparation 1 was used as the substrate material in which different kirigami patterns were cut and was incorporated into a diaper. Samples of the topical surge were cut with a semicircle (“SC”) slit pattern, such as shown in FIG. 4A where the semicircle slits are inverted and offset relative to each other. The slitted surge materials, starting at a length of 178 mm, were then stretched either about 11-12% (to about 200 mm), about 26-27% (to about 227 mm), or about 44-46% (to about 260 mm), such that the slits opened into semicircular shaped openings (see FIG. 4B). It is evident upon inspection that the extent of z-deformation increased as the level of stretch increased. Furthermore, for a given strain, it was evident that greater Z-deformation occurred when the semicircle pattern is used versus the wave pattern. The slitted, stretched surge materials were then adhesively bonded to a nonwoven bodyside liner or other nonwoven supporting layer.

[0079] Preparation 3 - A 50 gsm topical surge material comprising 100% 1.5 denier hollow polyethylene (“PE”) / polyethylene terephthalate (“PET”) bicomponent fibers was used as the substrate material in which different kirigami patterns were cut and was incorporated into a diaper. Samples of the topical surge were cut with an arc slit pattern, such as shown in FIG. 6A. The slitted surge material, starting at a length of 414 mm, was then stretched to about 16% (to about 480 mm), such that the slits opened into arc shaped openings (see FIG. 6B). The slitted, stretched surge material was then ultrasonically bonded to a nonwoven bodyside liner or other nonwoven supporting layer.

[0080] FIGS. 8A-8F, 9A-9F, and 10A-10B show 3D scans of ROIs for specimens prepared according to Preparations 1-3 and stretched in the X-direction to the stretch lengths and percentages set forth in Table 1 below. Table 1 also sets forth the measured surface roughness for each specimen that was calculated based on the surface roughness formula included above. Between 10,000 and 30,000 points were measured for each scanned specimen.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545

[0081] Table 1 :

[0082] As seen in Table 1, the surface roughness for each specimen prepared according to Preparations 1 and 2 generally increases as the amount the specimen is stretched increases. Further, the specimens prepared according to Preparation 1 (i.e., cut with the wave slit pattern) tend to have a lower measured surface roughness than those specimens prepared according to Preparation 2 (i.e., cut with the semicircle slit pattern).

[0083] The same area of some of the ROIs for the stretched, slitted materials presented in Table 1 were each scanned multiple times (the wave and semicircular specimens were scanned five times; the arc specimen was scanned two times), and the measured averages and standard deviations for their surface roughness are set forth in Table 2 below.

[0084] Table 2:PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545As can be seen based on this data, the 260 mm (44% stretch) wave specimen and the 200 mm (11% stretch) semicircular specimen are not distinguishable based on surface roughness alone.

[0085] Internal consumer testing was conducted to provide feedback on diapers containing the specimens of the six kirigami topical surge materials detailed in Preparations 1 and 2 in a sight and handling study. The individuals who were surveyed were asked to look at the specimens and to touch and feel them. Next, each individual was asked “Which diaper(s) would you choose for being soft to the skin?” and “Which diaper(s) would you choose for being rough to the skin?”. The individuals were given the option to select more than one diaper for each question.

[0086] The results of the internal consumer testing are shown in Table 3 below. The specimens with a rating of “A” or “B” in the “Soft on Skin” category are considered acceptable for consumer use, whereas specimens with a rating of “A” in the “Rough on Skin” category are considered risky for consumer use as these may be perceived as rough or cause skin irritation. The three specimens deemed acceptably soft on the skin based on the internal consumer testing (i.e., those that received a rating of “A” or “B” in the “Soft on Skin” category) include the 11% stretch wave specimen, the 26% stretch wave specimen, and the 11% stretch semicircular specimen. The three specimens deemed risky for use based on the internal consumer testing (i.e., those that received a rating of “A” in the “Rough on Skin” category) include the 44% stretch wave specimen, the 26% stretch semicircular specimen, and the 44% stretch semicircular specimen.

[0087] Table 3:PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545Soft on Skin Rough on Skin

[0088] Comparative Example 1 :

[0089] The results of the internal consumer testing in Table 3 may be compared to the surface roughness data set forth in Tables 1 and 2 for the semicircular and wave slit patterns. The comparison yields minor correlations between the individual surface roughness data in Table 1 and the internal consumer testing for softness and roughness in Table 3. However, the surface roughness average and standard deviation data set forth in Table 2 shows that the 44% stretch wave specimen and the 11% stretch semicircular specimen have essentially indistinguishable values (1.43 vs. 1.41, respectively). The internal consumer testing, however, demonstrates a strong difference in the assessments for softness between these two specimens in that the 44% stretch wave specimen performed worse than the 11% stretch semicircular specimen (with the 44% stretch wave specimen being chosen as being “Soft on Skin” only 19% of the time compared to the 11% semicircular specimen being chosen as being “Soft on Skin” 44% of the time). This lack of correlation of the internal consumer testing data with the measured average surface roughness was an unexpected finding.

[0090] Comparative Example 2:

[0091] FIG. 11 is a cumulative distribution function graph of the AHD calculations for the 3D scans of all seven specimens noted in Tables 1 and 2. For those specimens with “n=l” indicated in the legend, the AHD calculations are based on a single scan of the ROI for the specimen. For the specimen with “n=2” indicated in the legend, the AHD calculation is based on two scans of the ROI for the specimen. For those specimens with “MEAN” indicated in the legend, the AHDPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 calculations are based on five scans of the ROI for the specimen after which the mean is taken. FIG. 11 graphically illustrates the cumulative probability (denoted on the x-axis of FIG. 11) that the AHD of a tested specimen is less than or equal to a certain value (denoted on the y-axis of FIG. 11). By way only of example and with reference to FIG. 11, there is an 80% chance that the AHD of the 11% stretch wave specimen is 1 mm or less. The results of the internal consumer testing in Table 3 may be compared with the curves in FIG. 11. This comparison again yields minor correlations between AHD and the internal consumer testing for softness and roughness. One would expect that the specimens having a higher probability of lower AHD values (i.e., less surface roughness) would seem softer to the consumer. However, FIG. 11 demonstrates that such is not always the case. For example, the curve for the 44% stretch wave specimen and the 11% stretch semicircular specimen cross in FIG. 11, after which larger AHDs are more probable for the 11% stretch semicircular specimen than the 44% stretch wave specimen. Thus, one would expect that a consumer would deem the 11% stretch semicircular specimen rougher than the 44% stretch wave specimen. Yet consumer testing deemed the 11% stretch semicircular specimen acceptably soft and deemed the 44% stretch wave specimen rough on the skin. The internal consumer testing demonstrates a strong difference in the assessments for softness between these two specimens. This lack of correlation of the internal consumer testing data with the AHD was unexpected and evidenced that AHD is not an accurate or acceptable indicator of consumer perception of softness.

[0092] Example 1:

[0093] FIG. 12 is a cumulative distribution function graph of the NAHD calculations for the 3D scans of all seven specimens noted in Tables 1 and 2. For those specimens with “n=l” indicated in the legend, the NAHD calculations are based on a single scan of the ROI for the specimen. For the specimen with “n=2” indicated in the legend, the NAHD calculation is based on two scans of the ROI for the specimen. For those specimens with “MEAN” indicated in the legend, the NAHD calculations are based on five scans of the ROI for the specimen after which the mean is taken. FIG. 12 graphically illustrates the cumulative probability (denoted on the x-axis of FIG. 12) that the NAHD of a tested specimen is less than or equal to a certain value (denoted on the y-axis of FIG. 12). By way only of example and with reference to FIG. 12, there is an 80% chance that the NAHD of the 11% stretch semicircular specimen is less than 0.3. The results of the internal consumer testing in Table 3 may be compared with the curves in FIG. 12. This comparison yieldsPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 a perfect correlation between NAHD and the internal consumer testing for softness and roughness. More specifically, the specimens deemed the softest based on the internal consumer testing (i.e., the 11% stretch wave specimen, the 26% stretch wave specimen, and the 11% stretch semicircular specimen) had higher probabilities of lower NAHD values consistently across the graph (i.e., the curves for the 11% stretch wave specimen, the 26% stretch wave specimen, and the 11% stretch semicircular specimen did not intersect or cross the curves for the 44% stretch wave specimen, the 26% stretch semicircular specimen, and the 44% stretch semicircular specimen). Stated another way, at any given probability, the NAHD was less for each of the 11% stretch wave, the 26% stretch wave, and the 11% stretch semicircular specimens than for the 44% stretch wave, the 26% stretch semicircular, and the 44% stretch semicircular specimens. Thus, the NAHD is a more accurate predictor of consumer softness perception than AHD. If the NAHD curve for a specimen deemed to feel soft were to cross over the NAHD curve for another specimen deemed to feel rough, this would suggest that there was ambiguity as to whether the internal consumer prefers the softness of the one specimen versus the other and would cast doubt as to whether the NAHD could serve as an indicator to correlate z-deformation of the specimen with consumer perception of softness.

[0094] This data shows that a universal normalized parameter to characterize Z-deformation is helpful for accurate comparisons across materials cut with different styles of kirigami patterns. Moreover, such data permits characterizations that may be used to guide design of slitted substrate materials to accurately predict desired consumer perception. For example and with reference to the curves in FIG. 12, a stretched, slitted absorbent substrate material with a 75% probability that its NAHD value is less than or equal to 0.4 or is less than or equal to 0.3 may be perceived by consumers as being soft on skin; a stretched, slitted absorbent substrate material with a 95% probability that its NAHD value is less than or equal to 0.7 or is less than or equal to 0.6 may be perceived by consumers as being soft on skin; a stretched, slitted absorbent substrate material with a 65% or a 70% probability that its NAHD value is less than or equal to 0.3 may be perceived by consumers as being soft on skin; a stretched, slitted absorbent substrate material with a 25% or a 30% probability that its NAHD value is less than or equal to 0.1 may be perceived by consumers as being soft on skin; and / or a stretched, slitted absorbent substrate material with a 30% probabilityPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 that its NAHD value is less than or equal to 0.12 may be perceived by consumers as being soft on skin.

[0095] The semicircular and wave specimens in Tables 1 and 2 were tested utilizing a test method which determined a bowel movement (“BM”) pooled percent value. Such a test method is described as a “Determination of Residual Fecal Material Simulant” test method in U.S. Pat. No. 9,480,609, titled “Absorbent Article”, the entirety of which is hereby incorporated by reference. Table 4 below sets forth the results. A lower amount of BM pooling is generally preferred, as BM pooled on the surface of the diaper might contact a wearer’s skin, compromising dryness and risking infection. The BM pooling amounts are reduced for a given pattern as the stretch is increased, as would be expected due to greater Z-deformation and associated greater void volume generation. Also, the specimens with the semicircular pattern showed reduced pooling versus the specimens with the wave pattern at a given strain. This is also expected as materials cut with the semicircular pattern show greater Z-deformation after stretch than those cut with the wave pattern. An uncut surge material (devoid of slits but otherwise identical to the other specimens in Table 4) showed the highest pooling percentage. In some embodiments, the wave specimen stretched 26% provides a balance of BM pooling reduction and preferred consumer perceived softness.

[0096] Table 4:

[0097] Table 5 provided below sets forth data for BM pooling for the arc slit pattern specimen inTables 1 and 2 and illustrates the marked improvement through use of arc shaped openings asPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 compared to a control specimen devoid of openings in either the bodyside liner or the surge layer (the “Control”).

[0098] Table 5:

[0099] A collection of exemplary embodiments is provided below, including at least some explicitly enumerated as “Embodiments” providing additional description of a variety of example embodiments in accordance with the concepts described herein. These embodiments are not meant to be mutually exclusive, exhaustive, or restrictive; and the disclosure not limited to these example embodiments but rather encompasses all possible modifications and variations within the scope of the issued claims and their equivalents.

[0100] Embodiment 1. An absorbent article comprising a substrate comprising a plurality of openings formed when the substrate is provided with a plurality of discrete slits and subsequently stretched in a stretch direction to a stretched position and an adjacent material attached to the substrate when in the stretched position, wherein the substrate comprises a plurality of normalized absolute height difference values in the stretched position, and wherein at least 75% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.4.

[0101] Embodiment 2. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein the substrate is a topical material on a body facing surface of the absorbent article.

[0102] Embodiment 3. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein the substrate is provided internally within the absorbent article between a body facing surface of the absorbent article and an absorbent layer of the absorbent article.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545

[0103] Embodiment 4. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein at least 30% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.12.

[0104] Embodiment 5. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein at least 95% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.7.

[0105] Embodiment 6. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein the plurality of openings is provided in an array of rows that extend transverse to the stretch direction and / or in an array of columns that extend along the stretch direction.

[0106] Embodiment 7. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein the openings between adjacent rows are laterally offset with respect to one another.

[0107] Embodiment 8. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein each opening is wave shaped and is oriented across the substrate in a direction transverse to the stretch direction.

[0108] Embodiment 9. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein each opening is semi-circular shaped or arc shaped.

[0109] Embodiment 10. A method of making an absorbent article, the method comprising: providing a substrate comprising an initial length; creating a plurality of discrete slits in the substrate; thereafter stretching the substrate to a stretched position to provide a stretched substrate in which the plurality of discrete slits forms a plurality of openings in the stretched substrate in the stretched position; thereafter attaching the stretched substrate in the stretched position to an adjacent material to form at least part of the absorbent article, wherein the stretched substrate comprises a plurality of normalized absolute height difference values, and wherein at least 75% of the normalized absolute height difference values of the stretched substrate are less than 0.4.

[0110] Embodiment 11. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein creating a plurality of discrete slits in the substratePCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 comprises creating a plurality of discrete slits extending in adjacent rows across the substrate in a direction transverse to the stretch direction.[0U1] Embodiment 12. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein the slits between adjacent rows are laterally offset with respect to one another.

[0112] Embodiment 13. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein the plurality of discrete slits are semicircles and wherein the semicircles in adjacent rows are inverted within respect to one another.

[0113] Embodiment 14. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein the plurality of discrete slits are arcs.

[0114] Embodiment 15. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein the plurality of discrete slits are waves.

[0115] Embodiment 16. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein the absorbent article comprises a body facing surface and wherein the method further comprises positioning the stretched substrate in the absorbent article more proximate to the body facing surface than the adjacent material.

[0116] Embodiment 17. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein the absorbent article comprises a body facing surface and wherein the method further comprises positioning the stretched substrate in the absorbent article more distal to the body facing surface than the adjacent material.

[0117] Embodiment 18. The method of any of the preceding or subsequent embodiments or combination of embodiments, wherein stretching the substrate to a stretched position comprises stretching the substrate between 5% and 50% beyond the initial length of the substrate.

[0118] Embodiment 19. An absorbent article comprising an outer cover; a bodyside composite; and an absorbent body disposed between the outer cover and the bodyside composite, wherein the body side composite comprises a surge layer and an adjacent layer attached to the surge layer, wherein the surge layer is formed of a substrate comprising a plurality of openings formed when the substrate is provided with a plurality of discrete slits and subsequently stretched in a stretchPCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545 direction to a stretched position, wherein the substrate comprises a plurality of normalized absolute height difference values in the stretched position and wherein at least 75% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.4.

[0119] Embodiment 20. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein the surge layer is provided between the adjacent layer and the absorbent body.

[0120] Embodiment 21. The absorbent article of any of the preceding or subsequent embodiments or combination of embodiments, wherein the adjacent layer is provided between the surge layer and the absorbent body

[0121] The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. It should be appreciated that the various elements of concepts from the figures may be combined without departing from the spirit or scope of the invention.

[0122] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Directional references such as “up,” “down,” “top,” “bottom,” “left,” “right,” “front,” and “back,” among others, are intended to refer to the orientation as illustrated and described in the figure (or figures) to which the components and directions are referencing. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, or gradients thereof, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0123] As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. For example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context. However, the nearness of completion will be so as to have the same overall result as if absolute and total completion were obtained.

[0124] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. The invention is susceptible to various modifications and alternative constructions, and certain shown exemplary embodiments thereof are shown in the drawings and have been described above in detail. Variations of those preferred embodiments, within the spirit of the present invention, may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, it should be understood that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the abovedescribed elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

[0125] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Claims

PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-1512545CLAIMSThat which is claimed:

1. An absorbent article comprising: a substrate comprising a plurality of openings formed when the substrate is provided with a plurality of discrete slits and subsequently stretched in a stretch direction to a stretched position; and an adjacent material attached to the substrate when in the stretched position, wherein the substrate comprises a plurality of normalized absolute height difference values in the stretched position, and wherein at least 75% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.4.

2. The absorbent article of claim 1 , wherein the substrate is a topical material on a body facing surface of the absorbent article.

3. The absorbent article of claim 1, wherein the substrate is provided internally within the absorbent article between a body facing surface of the absorbent article and an absorbent layer of the absorbent article.

4. The absorbent article of claim 1, wherein at least 30% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.12.

5. The absorbent article of claim 1, wherein at least 95% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.7.

6. The absorbent article of claim 1, wherein the plurality of openings is provided in an array of rows that extend transverse to the stretch direction and / or in an array of columns that extend along the stretch direction.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-15125457. The absorbent article of claim 6, wherein the plurality of openings is provided in an array of rows, wherein the openings between adjacent rows are laterally offset with respect to one another.

8. The absorbent article of claim 1, wherein each opening is wave shaped and is oriented across the substrate in a direction transverse to the stretch direction.

9. The absorbent article of claim 1, wherein each opening is semi-circular shaped or arc shaped.

10. A method of making an absorbent article, the method comprising: providing a substrate comprising an initial length; creating a plurality of discrete slits in the substrate; thereafter stretching the substrate in a stretch direction and to a stretched position to provide a stretched substrate in which the plurality of discrete slits forms a plurality of openings in the stretched substrate in the stretched position; and thereafter attaching the stretched substrate in the stretched position to an adjacent material to form at least part of the absorbent article, wherein the stretched substrate comprises a plurality of normalized absolute height difference values, and wherein at least 75% of the normalized absolute height difference values of the stretched substrate are less than 0.4.

11. The method of claim 10, wherein creating a plurality of discrete slits in the substrate comprises creating a plurality of discrete slits extending in adjacent rows across the substrate in a direction transverse to the stretch direction.

12. The method of claim 11, wherein the slits between adjacent rows are laterally offset with respect to one another.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-151254513. The method of claim 10, wherein the plurality of discrete slits are semicircles and wherein the semicircles in adjacent rows are inverted within respect to one another.

14. The method of claim 10, wherein the plurality of discrete slits are arcs.

15. The method of claim 10, wherein the plurality of discrete slits are waves.

16. The method of claim 10, wherein the absorbent article comprises a body facing surface and wherein the method further comprises positioning the stretched substrate in the absorbent article more proximate to the body facing surface than the adjacent material.

17. The method of claim 10, wherein the absorbent article comprises a body facing surface and wherein the method further comprises positioning the stretched substrate in the absorbent article more distal to the body facing surface than the adjacent material.

18. The method of claim 10, wherein stretching the substrate to a stretched position comprises stretching the substrate between 5% and 50% beyond the initial length of the substrate.

19. An absorbent article comprising: an outer cover; a bodyside composite; and an absorbent body disposed between the outer cover and the bodyside composite, wherein the bodyside composite comprises a surge layer and an adjacent layer attached to the surge layer, wherein the surge layer is formed of a substrate comprising a plurality of openings formed when the substrate is provided with a plurality of discrete slits and subsequently stretched in a stretch direction to a stretched position, wherein the substrate comprises a plurality of normalized absolute height difference values in the stretched position and wherein at least 75% of the normalized absolute height difference values of the substrate in the stretched position are less than 0.4.PCT Patent Application KCC Ref. No.: 65130832PCT02 Attorney Ref. No.: 109296-151254520. The absorbent article of claim 19, wherein the surge layer is provided between the adjacent layer and the absorbent body.

21. The absorbent article of claim 19, wherein the adj acent layer is provided between the surge layer and the absorbent body.

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