Molded nonwoven fabric
By continuously winding fiber formation on the mold forming belt, the problem of insufficient performance of the three-dimensional surface forming non-textiles in the prior art is solved, and a high-performance three-dimensional non-textile used in the fields of absorbent products, clothing and medical products is achieved, which maintain good performance and shape during use and packaging.
Patent Information
- Application Number
- JP2022107075
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2017-01-31
- Filing Date
- 2022-07-01
- Publication Date
- 2025-04-08
- Estimated Expiration
- 2038-01-25
AI Technical Summary
There is a lack of improved three-dimensional surface-forming non-textiles in the prior art, especially in the fields of absorbent products, clothing and medical products, and it is difficult to maintain the integrity of the three-dimensional surface-forming elements in compressed packaging.
A three-dimensional non-textile formed on the mold forming belt is employed using continuous winding fibers. This method directly forms a non-textile with three-dimensional surface forming elements during a single molding process, and ensures the performance and shape of the non-textile during use and packaging through specific fiber distribution and compaction methods.
Improved three-dimensional non-textiles used in the fields of absorbent products, clothing and medical products are achieved, which maintain good absorption performance, flexibility and physical integrity during use, and reduce the loss of three-dimensional surface forming elements in compressed packaging.
Smart Images

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Abstract
Description
[Technical field]
[0001] The present invention relates to formed three-dimensional nonwoven fabrics and articles made from formed three-dimensional nonwoven fabrics. [Background technology]
[0002] Nonwoven fabrics are useful in a wide variety of applications, including absorbent personal care products, clothing, medical applications, and cleaning applications. Nonwoven personal care products include baby care articles such as diapers, pediatric care articles such as training pants, feminine care articles such as sanitary napkins, and adult care articles such as incontinence products, pads, and pants. Nonwoven clothing includes medical apparel such as protective workwear and surgical gowns. Other nonwoven medical applications include nonwoven wound dressings and surgical dressings. Nonwoven cleaning applications include towels and wipes. Still other applications of nonwoven fabrics are well known. The above list is not considered to be exhaustive.
[0003] Various properties of nonwoven fabrics determine their suitability for different applications. Nonwoven fabrics can be processed to have different combinations of properties to meet different needs. Various properties of nonwoven fabrics include liquid handling properties such as wettability, distribution, and absorbency, strength properties such as tensile strength and tear strength, softness properties, durability properties such as abrasion resistance, and aesthetic properties. The physical form of the nonwoven fabric also affects the functionality and aesthetic properties of the nonwoven fabric. Nonwoven fabrics are initially formed as sheets that can have a substantially planar, even surface when placed on a flat surface, or can have an array of surface features such as holes, protrusions, or both. Nonwoven fabrics with holes or protrusions are often referred to as three-dimensionally formed nonwoven fabrics. The present disclosure relates to three-dimensionally formed nonwoven fabrics.
[0004] Despite past advances in the field of nonwoven fabrics, there remains a need for improved nonwoven fabrics having three-dimensional surface features.
[0005] Additionally, there remains a need for processes and apparatus for producing improved nonwoven fabrics having three-dimensional surface features.
[0006] Additionally, a need remains for articles, including absorbent articles, that utilize improved nonwoven fabrics having three-dimensional surface features.
[0007] Additionally, there remains a need for absorbent articles using nonwoven fabrics having three-dimensional surface features that can be packaged in a compressed form while minimizing loss of the three-dimensional surface features when opened from the package.
[0008] Additionally, there remains a need for absorbent articles that utilize soft spunbond nonwoven fabrics having three-dimensional surface forming elements that exhibit low fuzzing characteristics during use.
[0009] Additionally, there remains a need for improved nonwoven fabrics that have three-dimensional surface features and that combine softness and physical integrity as measured by the Tissue Softness Analyzer sold by Emtec Electronic GmbH.
[0010] Further, there is a need for improved nonwoven fabrics having three-dimensional surface features that combine microzone and physical integrity with at least one region of the microzone being hydrophobic and a different region of the same microzone being hydrophilic. Summary of the Invention [Problem to be solved by the invention]
[0011] Additionally, there remains a need for a package for absorbent articles made of soft nonwoven materials that has a lower stack height within the bag compared to conventional absorbent article packages, thereby making the package easier for caregivers to handle and store, and that allows manufacturers to enjoy lower distribution costs without compromising the aesthetics, clarity, absorbency, or softness of the absorbent articles as manufactured. [Means for solving the problem]
[0012] A nonwoven fabric is disclosed. The nonwoven fabric can include a first surface and a second surface, and a visually distinguishable pattern of three-dimensional features on one of the first surface or the second surface. Each of the three-dimensional features can define a microzone including a first region and a second region. The first and second regions can have a difference in value of an intensive property, the intensive property being one or more of thickness, basis weight, or volume density, and in at least one of the microzones, the first region is hydrophobic and the second region is hydrophilic. [Brief description of the drawings]
[0013] [Figure 1] FIG. 1 is a photographic representation of an example of the present disclosure. [Diagram 2] FIG. 1 is a photographic representation of an example of the present disclosure. [Diagram 3] FIG. 1 is a photographic representation of an example of the present disclosure. [Figure 4] FIG. 2 is a cross-sectional view of a portion of the fabric of the present disclosure shown in FIG. [Figure 5A] FIG. 2 is a schematic diagram showing a cross-section of a filament formed of a primary component A and a secondary component B in a side-by-side arrangement. [Figure 5B] FIG. 2 is a schematic diagram showing a cross section of a filament formed of a primary component A and a secondary component B in an eccentric sheath / core arrangement. [Figure 5C] FIG. 2 is a schematic diagram showing a cross-section of a filament formed of a primary component A and a secondary component B in a concentric sheath / core arrangement. [Figure 6] FIG. 1 is a perspective photograph of a trilobal bicomponent fiber. [Figure 7]FIG. 1 is a schematic diagram of an apparatus for producing the fabric of the present disclosure. [Figure 8] FIG. 2 is a detailed partial view of an apparatus for bonding a portion of a fabric of the present disclosure. [Figure 9] FIG. 2 is a further detailed partial view of an apparatus for bonding a portion of a fabric of the present disclosure. [Figure 10] FIG. 2 is a detailed partial view of an apparatus for optionally further bonding portions of the fabric of the present disclosure. [Figure 11] FIG. 1 is a photographic representation of an example of the present disclosure. [Figure 12] FIG. 2 is a photograph of a portion of a forming belt useful in the present disclosure. [Figure 13] 13 is a cross-sectional view of a portion of the forming belt shown in FIG. 12. [Figure 14] FIG. 13 is an image of a portion of a mask used in making the forming belt shown in FIG. 12. [Figure 15] FIG. 17 is an image of a portion of a mask used in making the forming belt shown in FIG. 16. [Figure 16] FIG. 2 is a photograph of a portion of a forming belt useful in the present disclosure. [Figure 17] FIG. 19 is an image of a portion of a mask used in making the forming belt shown in FIG. 18. [Figure 18] FIG. 2 is a photograph of a portion of a forming belt useful in the present disclosure. [Figure 19] FIG. 2 is a photograph of a portion of a forming belt useful in the present disclosure. [Figure 20] FIG. 20 is an image of a mask used in making the forming belt shown in FIG. 19. [Figure 21] FIG. 20 is a photographic representation of a fabric of the present disclosure formed on the forming belt shown in FIG. 19. [Figure 22] FIG. 2 is a schematic perspective view of a forming belt of the present disclosure. [Diagram 23] FIG. 1 is a plan view of a nonwoven substrate comprising a nonwoven fabric of the present disclosure. [Figure 24] FIG. 1 is a plan view of a nonwoven substrate comprising a nonwoven fabric of the present disclosure. [Figure 25A] FIG. 2 is a plan view of a fabric of the present disclosure with a portion cut out to measure local basis weight. [Figure 25B] FIG. 2 is a plan view of a fabric of the present disclosure with a portion cut out to measure local basis weight. [Figure 26] 1 is a graph illustrating the cross-sectional variation in basis weight of fabrics of the present disclosure. [Figure 27] FIG. 1 is a schematic diagram of a package of the present disclosure. [Figure 28] FIG. 1 is a plan view of an absorbent article of the present disclosure. [Figure 29] FIG. 1 is a plan view of an absorbent article of the present disclosure. [Diagram 30] 29 is a cross-sectional view of section 29-29 in FIG. 28. [Diagram 31] FIG. 1 is a plan view of an absorbent article of the present disclosure. [Diagram 32] 32 is a cross-sectional view of section 32-32 in FIG. 31. [Diagram 33] FIG. 1 is a plan view of an absorbent article of the present disclosure. [Diagram 34] 34 is a cross-sectional view of section 34-34 in FIG. 33. [Diagram 35] 35 is a cross-sectional view of section 35-35 in FIG. 33. [Diagram 36] FIG. 1 is a photographic representation of an example of the present disclosure. [Figure 37] FIG. 1 is a photographic representation of an example of the present disclosure. [Figure 38] FIG. 1 is a photographic representation of an example of the present disclosure. [Figure 39] FIG. 39 is a photograph of a cross section of the example shown in FIG. 38. [Diagram 40] 1 is a perspective micro-CT image of an example of the present disclosure. [Diagram 41] 1 is a perspective micro-CT image of an example of the present disclosure. [Diagram 42] FIG. 42 is a micro-CT image of a cross section of the example shown in FIG. 40 and FIG. 41. [Diagram 43] 42 is a micro-CT planar image of the example shown in FIG. 40 and FIG. 41. [Diagram 44] 1 is a graphical depiction of the different effects of the disclosed invention. [Diagram 45] 1 is a photographic image of a portion of an example of the present disclosure. [Diagram 46]1 is a photographic image of a portion of an example of the disclosed invention. [Figure 47] 1 is a photographic image of a portion of an example of the disclosed invention. [Figure 48] 1 is a photographic image of a portion of an example of the disclosed invention. [Figure 49] FIG. 49 is a photograph of a cross section of the example shown in FIGS. 47 and 48. [Figure 50] 1 is a photographic image of a portion of an example of the disclosed invention. [Figure 51] 1 is a photographic image of a portion of an example of the disclosed invention. [Figure 52] 1 is a photographic image of a portion of an example of the disclosed invention. [Figure 53] 1 is a photographic image of a portion of an example of the disclosed invention. [Figure 54] 42 is a micro-CT planar image of the example shown in FIG. 40 and FIG. 41 after further processing. [Figure 55] FIG. 55 is a graphical depiction of the different effects of the disclosed invention shown in FIG. 54. [Figure 56] FIG. 1 is a schematic diagram of an apparatus for producing the fabric of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] The present disclosure provides a molded nonwoven fabric formed directly on a molded forming belt by continuous spunbond filaments in a single forming process. The fabric of the present disclosure can assume a shape corresponding to the shape of the forming belt. The fabric of the present disclosure formed on the forming belt of the present disclosure in the method of the present disclosure can be particularly useful for use in personal care articles, garments, medical products, and cleaning products. The molded nonwoven fabric can be fluid permeable for use as a topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer of a diaper, or as a topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer of a sanitary napkin, or as a topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer of an adult incontinence pad or pant, or as a pad of a floor cleaning implement.
[0015] Useful features of nonwoven fabrics are described in some embodiments herein in terms of the total area of the nonwoven fabric. The total area can be an area determined by dimensions suitable for a particular application for which various features of the present invention provide useful properties. For example, the total area of a fabric can be the total area of a fabric having dimensions that make the fabric suitable for use as a topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer of a diaper, or as a topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer of a sanitary napkin, or as a topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer of an adult incontinence pad or pant, or as a pad for a floor cleaning device. Thus, the total area can be based on width and length dimensions ranging from 3 cm wide to 50 cm wide and 10 cm long to 100 cm long, whereby the total area is less than 30 cm wide. 2 ~500cm 2 The above ranges include all integer dimensions between the range boundaries as if they were expressly stated. For example, 176 cm is defined by a width of 11 cm and a length of 16 cm. 2 The total area of the shaped nonwoven fabric is disclosed within the ranges above. As will be understood from the description herein, the total area of the shaped nonwoven fabric can be less than the area of the web of nonwoven material of which it is a part when it is commercially produced. That is, a commercially produced web of a given nonwoven material may include multiple shaped nonwoven fabrics of the present invention, each having a total area less than the area of the web from which it is made.
[0016] Photographs of a representative example of a shaped nonwoven fabric 10 are shown in Figures 1-3. The shaped nonwoven fabric 10 can be a spunbond nonwoven substrate having a first surface 12 and a second surface 14. In Figures 1-3, the second surface 14 faces the viewer and is opposite the first surface 12, which is not visible in Figures 1-3 but is shown in Figure 4. The term "surface" is used broadly to refer to both sides of the web for purposes of description and is not intended to imply any necessary flatness or smoothness. The shaped nonwoven fabric 10 is soft and flexible, but is described in a flat state relative to one or more XY planes that are parallel to the flat state and correspond to the cross direction (CD) and machine direction (MD) planes, respectively, in web manufacturing technology, as shown in Figures 1-3. The length L in the MD and width W in the CD determine the overall area A of the nonwoven fabric 10. As shown in FIG. 4, which is a cross-section of a portion of the nonwoven fabric 10 shown in FIG. 1, for purposes of illustration, the three-dimensional features of the shaped nonwoven fabric are described as extending outward in the Z direction from the XY plane of the first surface 16 (see FIG. 4). In one embodiment, the maximum dimension of the three-dimensional features in the Z direction can define the maximum distance between the plane of the first surface 16 and the XY plane of the second surface 18, which can be measured as the average caliper AC of the nonwoven fabric 10. The average caliper can be measured by optical non-contact means or by an instrument that measures the caliper of a nonwoven fabric placed under a predetermined pressure between spaced apart flat plates. While not all three-dimensional features need have the same maximum dimension in the Z direction, multiple three-dimensional features can have substantially the same maximum dimension in the Z direction as determined by the fiber laydown process and forming belt properties described below.
[0017] The representative fabrics shown in Figures 1-4 (as well as other fabrics disclosed herein) are fluid permeable. In one embodiment, the entire fabric can be considered fluid permeable. In one embodiment, a region or area (described below) can be fluid permeable. Fluid permeable as used herein in reference to a fabric means that the fabric has at least one area that allows liquids to pass therethrough under the use conditions of the consumer product. For example, if the fabric is used as a topsheet in a disposable diaper, the fabric can have at least one area that has a level of fluid permeability that allows urine, feces, menstrual fluid, or any other bodily fluids to pass through to the underlying absorbent core. Fluid permeable as used herein in reference to a region means that the region exhibits a porous structure that allows liquids to pass therethrough.
[0018] As shown in Figures 1-4, the nonwoven fabric 10 can have a regularly repeating pattern of a plurality of individual, recognizably different three-dimensional features, including a first three-dimensional feature 20 and a second three-dimensional feature 22 as shown in Figures 2 and 3, and a third three-dimensional feature 24. For example, in Figure 1, the heart-shaped first three-dimensional feature 20 is recognizably different from the smaller, generally triangular second three-dimensional feature 22. The recognizable difference may be visual, such as a recognizably different size and / or shape.
[0019] The three-dimensional features of the nonwoven fabric 10 can be formed by directly depositing fibers, such as by carding, air laying, solution spinning, or melt spinning, onto a forming belt having a corresponding pattern of three-dimensional features. In one aspect, the nonwoven fabric 10 is formed on a forming belt that determines the shape of the three-dimensional features of the fabric 10. Importantly, however, as described herein, the apparatus and method of the present invention produce a nonwoven fabric 10 such that, in addition to taking the shape of the forming belt, the attributes of the forming belt and the equipment that forms the fabric impart useful properties for use in personal care articles, garments, medical products, and cleaning products. In particular, due to the nature of the forming belt and other equipment elements as described below, the three-dimensional features of the nonwoven fabric 10 have intensive properties that can vary between first and second regions within a microregion (described in more detail below), or from one feature to another, to impart useful properties to the nonwoven fabric 10 when used in personal care articles, garments, medical products, and cleaning products. For example, the first three-dimensional feature 20 may have a different basis weight or density than the second three-dimensional feature 22, which may both have a different basis weight or density than the third three-dimensional feature 24, thereby providing useful aesthetic and functional properties related to fluid acquisition, distribution and / or absorbency in the diaper or sanitary napkin.
[0020] The difference in intensive properties between the different three-dimensional forming elements of nonwoven fabric 10 is believed to be due to the fiber distribution and compaction resulting from the apparatus and methods described below. The fiber distribution occurs during the fiber laydown process as opposed to post-manufacturing processes such as hydroentangling or embossing. The fibers are believed to be more stable and permanently formed within nonwoven fabric 10 because the fibers are free to move during processes such as the melt spinning process, with their movement being determined by the nature and air permeability of the forming elements of the forming belt, as well as other processing parameters.
[0021] As seen in Figures 1-3 and understood from the description herein, the different three-dimensional features are bounded by visually distinct regions (with respect to the interior of the three-dimensional features) that may be in the form of a closed figure (such as the heart shape in Figures 1 and 3 and the diamond shape in Figures 2 and 3). Such a closed figure may be a closed figure that includes curves, such as the heart shape in Figures 1 and 3. The outlined visually distinct region may be a region of the nonwoven fabric 10 that is closest to the first surface 12 in the Z direction, such as region 21 shown in Figure 4, and that may lie at least partially within or on the first plane 16 when in a flat state. For example, as shown in Figure 1, the first three-dimensional feature 20 is heart-shaped, and an exemplary first three-dimensional feature 20A as shown in the figure is defined as a closed heart-shaped element that includes curves. A curvilinear element can be understood as a linear element having a tangent vector V at any point along its length, and a closed shape is one in which the tangent vector V has both MD and CD components that vary in value over more than 50% of the length of the linear element of the closed shape. Of course, the shape need not be 100% completely closed, but the linear element may have breaks that do not detract from the overall impression of the closed shape. As described below in connection with the forming belt, the contoured, visually distinct curvilinear closed heart-shaped element is formed by corresponding closed, heart-shaped raised elements on the forming belt to form a closed heart shape on the fabric 10. In a repeating pattern, the individual shapes (heart shapes in the case of the first three-dimensional feature of FIG. 1) can provide an aesthetically pleasing, soft, pillow-like feature over the entire area OA of the second surface 14 of the fabric 10. In embodiments in which nonwoven fabric 10 is used as a topsheet for a diaper or sanitary napkin, having second surface 14 of nonwoven fabric 10 facing the body can provide superior aesthetic and performance benefits related to softness, compression resistance, and fluid absorbency.
[0022] In particular, in the regular repeating pattern of closed three-dimensional features shown in Figures 1-3, without being bound by theory, it is believed that the different feature dimensions, the average basis weight of the entire fabric 10 over the entire area, and other processing parameters described below that define the different intensive properties contribute to the effective improvement of compression recovery. It is believed that the multiple relatively closely spaced, relatively small, relatively pillow-like three-dimensional features act as springs that resist compression and recover when the compressive force is removed. Compression recovery is important, for example, in the topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer of personal care articles such as diapers, sanitary napkins, or adult incontinence pads, diapers, or pants, since these articles are generally packaged and folded in a compressed state. In the manufacture of personal care products, it is desirable to maintain most, if not all, of the as-built caliper for aesthetic and performance purposes. The three-dimensionality of the formed features provides important aesthetic benefits due to the soft look and feel and the pleasing appearance of well-defined shapes, including very small shapes such as the small hearts shown in FIG. 2. Such three-dimensional features also provide flexibility in use, improved absorbency, less leakage, and an overall improved use experience. However, the compression required during folding, packaging, shipping, and storage of personal care articles can cause the topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layers of the absorbent article to lose permanent caliper, thereby compromising the functional benefits of manufacture. The inventors have unexpectedly found that the nonwoven fabrics of the present disclosure retain a significant degree of their as-manufactured three-dimensional features after being compressed and packaged and distributed in a compressed and packaged state.
[0023] Table 1 below provides compression recovery data for two embodiments of the present disclosure. Example 1 corresponds to the nonwoven fabric 10 formed on the forming belt shown in FIG. 1 and described with reference to FIGS. 12 and 14. Example 2 corresponds to the nonwoven fabric 10 formed on the forming belt shown in FIG. 2 and described with reference to FIGS. 15 and 16. As can be seen from the data, the fabric 10 of the present disclosure exhibits significant compression recovery benefits as measured by compression aging tests. In one form, a package of absorbent articles having compression recovery properties of the present disclosure can have a reduced in-bag stack height while providing the aesthetic, absorbency, and softness benefits of the as-manufactured diaper or as if the diaper had never been compression packaged. The present invention provides a package with a reduced in-bag stack height that facilitates handling and storage of the package by the caregiver while reducing distribution costs for the manufacturer, both while maintaining the as-manufactured aesthetic clarity, absorbency, or softness performance of the absorbent article.
[0024] Example 1: A bicomponent spunbond nonwoven fabric was produced by spinning a polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) in a 50:50 ratio into a trilobal fiber, as shown in FIG. 6, which is a scanning electron micrograph (SEM) showing the cross section of a bicomponent trilobal fiber. The nonwoven fabric had a repeating pattern as described in FIG. 12 and was spun at 30 g / m2 onto a forming belt moving at a linear speed of about 25 m / min as described below in connection with FIGs. 7 and 8. 2 and spun in a repeating heart-shaped pattern as shown in Figure 1. The fibers of the fabric were further bonded on first side 12 by compression rolls 70, 72 (described below) heated to 130°C and wound onto reels in winder 75.
[0025] Example 2: A polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) were spun in a 50:50 ratio into the form of a trilobal fiber to produce a bicomponent spunbond nonwoven fabric as shown in FIG. 6, in which a scanning electron micrograph of the cross section of a bicomponent trilobal fiber is shown. The nonwoven fabric had a repeat pattern as described in FIG. 16 and was spun onto a forming belt moving at a linear speed of about 25 m / min as described below in connection with FIGS. 7 and 8 to produce a diamond repeat pattern as shown in FIG. 2 with an average basis weight of 30 g / m. 2 The fibers of the fabric were further bonded on the first surface 12 by compression rolls 70, 72 (described below) which were heated to 130°C.
[0026] [Table 1]
[0027] As can be seen from Table 1, the fabric 10 of the present invention retains a significant amount of caliper after compression at relatively high pressures. For example, the samples of Example 1 and Example 2 retained more than 70% of their initial average caliper after being tested by the compression aging test at a pressure of 35 KPa. The compression aging test simulates the conditions that the nonwoven fabric will be exposed to when it is packaged in a highly compressed package of diapers and maintained in that condition during distribution to consumers, after which the package is eventually opened by the consumer.
[0028] Melt spinning can be used in the present disclosure, which does not result in mass loss in the extrudate. Melt spinning is distinct from other spinning processes, such as wet or dry spinning from a solution, which leads to mass loss as the solvent is removed by volatilization or diffusion from the extrudate.
[0029] Melt spinning can be carried out at about 150°C to about 280°C, or in some embodiments, from about 190°C to about 230°C. The fiber spinning speed can be greater than 100 m / min, from about 1,000 to about 10,000 m / min, from about 2,000 to about 7,000 m / min, or from about 2,500 to about 5,000 m / min. The spinning speed can affect the brittleness of the spun fiber, but generally the higher the spinning speed, the less brittle the fiber. Continuous fibers can be produced by spunbonding or meltblown processes.
[0030] The nonwoven fabric 10 of the present disclosure may include continuous multicomponent polymer filaments comprising a primary polymer component and a secondary polymer component. The filaments may be continuous bicomponent filaments comprising a primary polymer component A and a secondary polymer component B. The bicomponent filaments have a cross section, a length, and a circumferential surface. Components A and B may be disposed in substantially distinct zones across the cross section of the bicomponent filament and may extend continuously along the length of the bicomponent filament. The secondary component B constitutes at least a portion of the circumferential surface of the bicomponent filament continuously along the length of the bicomponent filament. The polymer components A and B may be melt spun into a multicomponent fiber in conventional melt spinning equipment. The equipment is selected based on the desired morphology of the multicomponent. Commercially available melt spinning equipment is available from Hills, Inc., Melbourne, Florida. Spinning temperatures range from about 180° C. to about 230° C. Processing temperatures depend on the chemical nature, molecular weight, and concentration of each component. The bicomponent spunbond filaments can have an average diameter of about 6 to 40 μm, preferably about 12 to about 40 μm.
[0031] Components A and B can be arranged in a side-by-side configuration as shown in FIG. 5A or in an eccentric sheath / core configuration as shown in FIG. 5B to obtain filaments that naturally undergo helical crimping. Alternatively, components A and B can be arranged in a concentric sheath-core configuration as shown in FIG. 5C. Additionally, components A and B can be arranged in a multi-lobal sheath-core configuration as shown in FIG. 6. Other multicomponent fibers can be produced using the compositions and methods of the present disclosure. Bicomponent and multicomponent fibers can be in a split pie configuration, ribbon configuration, islands-in-the-sea configuration, or any combination thereof. The sheath can be continuous or discontinuous around the core. The weight ratio of sheath to core is about 5:95 to about 95:5. The fibers of the present disclosure can have different geometric shapes, including circular, elliptical, star, rectangular, and various other eccentric shapes.
[0032] Methods for extruding multicomponent polymer filaments into such configurations are well known to those skilled in the art.
[0033] A wide variety of polymers are suitable for practicing the present disclosure, including polyolefins (such as polyethylene, polypropylene, and polybutylene), polyesters, polyamides, polyurethanes, elastomeric materials, etc. Non-limiting examples of polymeric materials that can be spun into filaments include natural polymers (such as starch, starch derivatives, cellulose and cellulose derivatives, hemicellulose, hemicellulose derivatives, chitin, chitosan, polyisoprene (cis and trans), peptides, polyhydroxyalkanoates, etc.), and synthetic polymers (including, but not limited to, thermoplastic polymers such as polyesters, nylons, polyolefins (such as polypropylene, polyethylene, polyvinyl alcohol and polyvinyl alcohol derivatives), sodium polyacrylate (absorbent gelling materials), and copolymers of polyolefins such as polyethylene-octene, or polymers comprised of monomer blends of propylene and ethylene, and biodegradable or compostable thermoplastic polymers such as polylactic acid filaments, polyvinyl alcohol filaments, and polycaprolactone filaments). In one example, the thermoplastic polymer is selected from the group consisting of polypropylene, polyethylene, polyester, polylactic acid, polyhydroxyalkanoates, polyvinyl alcohol, polycaprolactone, styrene butadiene styrene block copolymers, styrene isoprene styrene block copolymers, polyurethanes, and mixtures thereof. In another example, the thermoplastic polymer is selected from the group consisting of polypropylene, polyethylene, polyester, polylactic acid, polyhydroxyalkanoates, polyvinyl alcohol, polycaprolactone, and mixtures thereof. Polymers may also include those derived from biologically derived monomers, such as bio-polyethylene or bio-polypropylene.
[0034] The primary component A and secondary component B can be selected such that the resulting bicomponent filaments provide improved nonwoven adhesion and substrate flexibility. The primary polymer component A has a melting point lower than the melting point of the secondary polymer component B.
[0035] The primary polymer component A may include polyethylene or a random copolymer of propylene and ethylene. The secondary polymer component B may include polypropylene or a random copolymer of propylene and ethylene. Polyethylene includes linear low density polyethylene and high density polyethylene. Additionally, the secondary polymer component B may include additives to improve the natural helical crimp of the filaments, reduce the bonding temperature of the filaments, and increase the abrasion resistance, strength, and flexibility of the resulting fabric.
[0036] Inorganic fillers such as oxides of magnesium, aluminum, silicon, and titanium may be added as inexpensive fillers or processing aids. Other inorganic materials include hydrated magnesium silicate, titanium dioxide, calcium carbonate, clay, chalk, boron nitride, limestone, diatomaceous earth, mica, glass, quartz, and ceramics.
[0037] The filaments of the present invention further contain a slip additive in an amount sufficient to impart a desirable tactile feel to the fiber. As used herein, "slip additive" or "slip agent" refers to an external lubricant. When melt mixed with the resin, the slip agent slowly exudes or migrates to the surface during cooling or after fabrication to form a uniform, imperceptibly thin coating, thereby providing sustained lubrication. The slip agent is preferably a fast bloom slip agent and may be a hydrocarbon having one or more functional groups selected from hydroxide, aryl and substituted aryl, halogen, alkoxy, carboxylate, ester, unsaturated carbon, acrylate, oxygen, nitrogen, carboxyl, sulfate, and phosphate.
[0038] During manufacture, or in post-treatment, or even both, the nonwoven fabric of the present invention can be treated with surfactants or other agents to hydrophilize the web or to hydrophobize the web. This is standard practice for nonwoven fabrics used in absorbent articles. For example, nonwoven fabrics used in topsheets can be treated with hydrophilizing materials or surfactants to make the nonwoven fabric permeable to body exudates such as urine. In other absorbent articles, the topsheet can be kept in its natural hydrophobic state or made even more hydrophobic by adding hydrophobizing materials or surfactants.
[0039] Materials suitable for preparing the multicomponent filaments of the fabrics of the present disclosure include PH-835 polypropylene available from LyondellBasell and Aspun-6850-A polyethylene available from Dow chemical company.
[0040] When polyethylene is component A (sheath) and polypropylene is component B (core), the bicomponent filaments may be composed of about 5-95% by weight polyethylene and about 95 to about 5% by weight polypropylene. The filaments may be composed of about 40-60% by weight polyethylene and about 60 to about 40% by weight polypropylene.
[0041] 7, an exemplary process line 30 for preparing the fabric 10 of the present disclosure is disclosed. The process line 30 is configured to produce a bicomponent continuous filament fabric, although it should be understood that the present disclosure also encompasses nonwoven fabrics formed with one component or multicomponent filaments having more than two components. The bicomponent filaments may be trilobal.
[0042] The process line 30 includes a pair of extruders 32 and 34 driven by extruder drives 31 and 33, respectively, for separately extruding a primary polymer component A and a secondary polymer component B. Polymer component A is charged to the corresponding extruder 32 from a first hopper 36, and polymer component B is charged to the corresponding extruder 34 from a second hopper 38. Polymer components A and B are fed from the extruders 32 and 34 through respective polymer conduits 40 and 42 to filters 44 and 45 and melt pumps 46 and 47, which can pump the polymers to a spin pack 48. Spinnerets for extruding bicomponent filaments are well known to those skilled in the art and will not be described in detail here.
[0043] Generally speaking, the spin pack 48 includes a housing that includes a plurality of plates stacked on top of each other with a pattern of openings arranged to form flow paths for directing the polymer components A and B separately through the spinneret. The spin pack 48 has openings arranged in one or more rows. The spinneret openings form a downwardly extending curtain of filaments as the polymers are extruded from the spinneret. For purposes of this disclosure, the spinneret can be configured to form bicomponent filaments of the sheath / core or side-by-side types shown in Figures 5A, 5B, and 5C, as well as non-circular fibers such as the trilobal fiber shown in Figure 6. Additionally, the fibers may be monocomponent, consisting of one polymer component, such as polypropylene.
[0044] The process line 30 also includes a quench blower 50 positioned adjacent to the curtain of filaments extending from the spinneret. Air from the quench blower 50 quenches the filaments extending from the spinneret. The quench air can be directed from one side of the filament curtain or from both sides of the filament curtain.
[0045] An attenuator 52 is positioned below the spinneret to receive the quenched filaments. Fiber drawing devices or aspirators used as attenuators in melt spinning of polymers are well known. Fiber drawing devices suitable for use in the process of the present disclosure include straight fiber attenuators of the type shown in U.S. Pat. No. 3,802,817, and eductive guns of the type shown in U.S. Pat. Nos. 3,692,618 and 3,423,266, the disclosures of which are incorporated herein by reference.
[0046] Generally speaking, the attenuator 52 has an elongated vertical passageway through which the filaments are drawn by drawing air entering from the sides of the passageway and flowing down the passageway. A shaped, endless, at least partially foraminous forming belt 60 is disposed below the attenuator 52 to receive the continuous filaments from the exit opening of the attenuator 52. The forming belt 60 is a belt and moves along guide rollers 62. A vacuum device 64 disposed below the portion of the forming belt 60 where the filaments are deposited draws the filaments against the forming surface. In FIG. 8, the forming belt 60 is shown as a belt, but it should be understood that the forming belt may take other forms, such as a drum. Details of particular shaped forming belts are described below.
[0047] In operation of process line 30, hoppers 36 and 38 are filled with polymer components A and B, respectively. Polymer components A and B are melted and extruded by extruders 32 and 34, respectively, through polymer conduits 40 and 42 and spin pack 48. The temperature of the molten polymer will vary depending on the temperature of the polymer used, but when polyethylene and polypropylene are used as polymer components A and B, respectively, the temperature of each polymer can range from about 190° C. to about 240° C.
[0048] As the extruded filaments extend below the spinneret, airflow from quench blower 50 at least partially quenches the filaments and, for certain filaments, induces crystallization of the molten filaments. The quench air can flow in a direction substantially perpendicular to the length of the filaments at a temperature of about 0° C. to about 35° C. and a speed of about 100 to about 400 feet per minute. The filaments can be quenched sufficiently prior to collection on forming belt 60 to allow for alignment of the filaments by forced air passing through the filaments and forming surface. Quenching the filaments reduces the tackiness of the filaments so that they do not stick too closely to one another before being bonded together, and allows for movement and alignment of the filaments on the forming belt during collection of the filaments on the forming belt and formation of the web.
[0049] After quenching, the filaments are drawn by the flow of the fiber draw system into the vertical passage of the attenuator 52. The attenuator can be positioned 30-60 inches below the bottom of the spinneret.
[0050] The filaments may be deposited from the exit opening of the attenuator 52 onto a shaped, moving forming belt 60. As the filaments contact the forming surface of the forming belt 60, a vacuum device 64 draws air and the filaments against the forming belt 60 to form a nonwoven web of continuous filaments having a shape that conforms to the shape of the forming surface. As mentioned above, because the filaments are quenched, they do not become excessively tacky, and the vacuum may move or align the filaments on the forming belt 60 as they are collected on the forming belt 60 and formed into the fabric 10.
[0051] The process line 30 further includes one or more bonding devices, such as cylindrical compression rolls 70 and 72, which form a nip through which the fabric can be compressed (i.e., calendered), and which can also be heated to bond the fibers. One or both of the compression rolls 70, 72 can be heated to provide enhanced properties and benefits to the nonwoven fabric 10 by bonding portions of the fabric. For example, it is believed that sufficient heating to provide thermal bonding improves the tensile properties of the fabric 10. The compression rolls can be a pair of smooth stainless steel rolls with independent heating controls. The compression rolls can be heated by electrical elements or by circulating hot oil. The gap between the compression rolls can be hydraulically controlled to apply a desired pressure to the fabric as it passes through the compression rolls on the forming belt. In one embodiment, if the caliper of the forming belt is 1.4 mm and the spunbond nonwoven fabric has a basis weight of 30 gsm, the nip gap between the compression rolls 70 and 72 can be about 1.4 mm.
[0052] In one embodiment, the upper compression roll 70 can be heated sufficiently to melt-bond the fibers on the first surface 12 of the fabric 10, thereby providing strength to the fabric so that it can be removed from the forming belt 60 without losing its integrity. For example, as shown in Figures 8 and 9, the belt 60 with the deposited spunbond fabric enters a nip formed by rolls 70 and 72 as the rolls 70 and 72 rotate in the direction indicated by the arrows. The heated roll 70 can form bonded fibers 80 on at least the first surface 12 of the fabric 10 by heating the portions of the nonwoven fabric 10 that are pressed against the roll 70 by the raised resin elements of the belt 60 (i.e., areas 21). As will be understood from the description herein, the bonded areas thus formed can have a pattern of the raised elements of the forming belt 60. For example, the bonded areas thus formed can be a substantially continuous network or a substantially semi-continuous network on the first surface 12 in areas 21 that form the same pattern as the hearts of Figures 1 and 11. By adjusting the temperature and residence time, the bonding may be limited primarily to the fibers closest to the first surface 12, or the thermal bonding may be extended to the second surface 14 as shown in Figure 11 (which also shows point bonds 90, described in more detail below) and Figures 45-49. The bonding may also be a discontinuous network, for example as point bonds 90, described below.
[0053] The raised elements of the forming belt 60 can be selected to establish various network characteristics of the bonded areas of the forming belt and nonwoven substrate 11 or nonwoven fabric 10. The network corresponds to the resin that makes up the raised elements of the forming belt 60 and can include substantially continuous, substantially semi-continuous, discontinuous, or combinations of these options. These networks can be descriptive of the raised elements of the forming belt 60 as they relate to the appearance or configuration of the network in the XY plane of the forming belt 60 or the three-dimensional features that make up the nonwoven substrate 11 or nonwoven fabric 10 of the present invention.
[0054] A "substantially continuous" network refers to a region in which any two points can be connected by an uninterrupted line that extends entirely within the region over the entire length of the line. That is, a substantially continuous network has substantial "continuity" in all directions parallel to the first plane and terminates only at the edges of the region. The term "substantially" in combination with "continuous" is intended to indicate that absolute continuity can be achieved, but that some deviations from absolute continuity can be tolerated as long as such deviations do not significantly affect the designed and intended performance of the fiber structure (or shaped member).
[0055] A "substantially semi-continuous" network structure refers to a region that has "continuity" in all directions except at least one direction parallel to the first plane, such that any two points cannot be connected by an uninterrupted line that extends entirely within the region over the entire length of that line. A semi-continuous structure may only have continuity in one direction parallel to the first plane. As with the continuous regions described above, absolute continuity in all directions except at least one direction is preferred, but some deviations from such continuity may be tolerated as long as such deviations do not significantly affect the performance of the fiber structure.
[0056] A "discontinuous" network refers to separate regions that are distinct and discontinuous in all directions parallel to a first plane.
[0057] After compression, the fabric leaves the forming belt 60 and can be calendered through the nip formed by the calender rolls 71, 73, after which the fabric can be wound onto a reel. As shown in the schematic cross-section of FIG. 10, these calender rolls can be stainless steel rolls having an engraved pattern roll 84 and a smooth roll 86. The engraved rolls can have ridges 88 that can provide additional compression and bonding to the fabric 10. The ridges 88 can be a regular pattern of relatively small, spaced apart "pins" that form a pattern of relatively small point bonds 90 within the nip of the calender rolls 71 and 73. The percentage of point bonds in the nonwoven fabric 10 can be between 3% and 30%, or between 7% and 20%. The engraved pattern can be in the form of a plurality of closely spaced regular generally cylindrical, generally flat-topped pins, with the height of the pins ranging from 0.5 mm to 5 mm, preferably 1 mm to 3 mm. The pin-bonded calender rolls can form closely spaced, regular point bonds 90 in the nonwoven fabric 10, as shown in Figure 11. Further bonding can be accomplished by, for example, hot air bonding.
[0058] As described below with respect to FIG. 56, through-air thermal bonding can be another approach to forming a high loft nonwoven structure that may be suitable for this application. Through-air thermal bonding involves applying hot air to the surface of the nonwoven. The hot air flows through holes in a plenum located directly above the nonwoven. However, the air is not forced through the nonwoven as in a typical hot air oven. Negative pressure or suction draws air into an open conveyor apron that supports the nonwoven as it passes through the oven. Drawing air through the nonwoven allows for a more rapid and uniform transfer of heat and minimizes distortion of the fabric. In addition to the traditional through-air bonding unit, it is also conceivable to mimic the through-air bonding process in this particular application by placing the bonding unit on top of a 3D belt with a vacuum installed under the belt.
[0059] Binders used in through-air heat bonding include crystalline binder fibers, bicomponent binder fibers, and powders. When using crystalline binder fibers or powders, the binder melts completely to form molten droplets throughout the cross section of the nonwoven. Cooling creates bonding at these points. In the case of sheath / core binder fibers, the sheath is the binder and the core is the carrier fiber. In one embodiment where the nonwoven includes sheath / core binder fibers, the sheath is made of polyethylene and the core is made of polypropylene. For such nonwovens, the air temperature for through-air heat bonding can range from 110°C to 150°C, and the residence time can range from 0.5 to 10 seconds, 5 to 30 seconds, or 30 to 60 seconds, since the through-air heat bonding time depends on the basis weight, the desired strength level, and the operating speed. Products made using through-air ovens tend to be bulky, open, soft, strong, extensible, breathable, and absorbent.
[0060] Point bonding, as used herein, is a method of thermally bonding nonwovens, webs, or substrates. In this method, the web is passed through a nip between two rolls, a heated male patterned or engraved metal roll and a smooth or patterned metal roll. The male patterned roll can have a number of raised, generally cylindrical pins that create circular point bonds. The smooth roll may or may not be heated depending on the application. In a nonwoven manufacturing line, the nonwoven, which may be a web of unbonded fibers, is fed into a calendar nip where the fiber temperature is raised to a point where the fibers are thermally fused together at the tips of the engraved points against the smooth roll. Heating times are typically on the order of milliseconds. The fiber properties depend on process settings such as roll temperature, web line speed, and nip pressure, all of which can be determined by one skilled in the art to obtain the desired degree of point bonding. Another type of point bonding, commonly known as high temperature calendar bonding, can consist of different geometric shapes for bonding (other than circular), such as ellipses, lines, circles, etc. In an exemplary embodiment disclosed herein, the point bonds can form a pattern of point bonds that are 0.5 mm diameter circles with a total bond area of 10%. Other embodiments include bond geometries where the raised pins have a longest dimension across the pin's bonding surface of about 0.1 mm to 2.0 mm, with a total bond area ranging from 5% to 30%.
[0061] As shown in FIG. 11, in one embodiment, the heated compression roll 70 can form a predetermined bond pattern, which may be a substantially continuous network bond pattern 80 (e.g., interconnected heart-shaped bonds) on the first surface 12 of the nonwoven fabric 10 (not shown in FIG. 11 because it faces away from the viewer), and the engraved calendar roll 73 can form relatively small point bonds 90 on the second surface 14 of the fabric 10. The point bonds 90 secure loose fibers that tend to cause fraying or pilling during use of the fabric 10. The advantages of the resulting structure of the nonwoven fabric 10 are most evident when used as a topsheet for a personal care article, such as a diaper or sanitary napkin. When used in a personal care article, the first surface 12 of the nonwoven fabric 10 can be relatively flat (relative to the second surface 14) and have relatively more bonds because the heated compression roll forms bonds 80 in areas of the fabric pressed by the raised elements of the forming belt 60. This bond provides structural integrity to the nonwoven 10, but may be relatively hard or rough against the skin of the user. Thus, the first surface 12 of the nonwoven 10 may face the inside of the article, i.e., away from the wearer's body, in a diaper or sanitary napkin. Similarly, the second surface 14 may face the body and contact the body during use. The relatively small point bonds 90 are less likely to be visually or tactilely perceived by the user, and the relatively soft three-dimensional features remain free of visually noticeable fuzzing and pilling while still feeling soft to the body during use. Additional bonds may be used instead of or in addition to the bonds described above.
[0062] The forming belt 60 can be made according to the methods and processes described in U.S. Patent No. 6,610,173 issued to Lindsay et al. on August 26, 2003, or U.S. Patent No. 5,514,523 issued to Trokhan et al. on May 7, 1996, or U.S. Patent No. 6,398,910 issued to Burazin et al. on June 4, 2002, or U.S. Patent Application Publication No. 2013 / 0199741 published in the name of Stage et al. on August 8, 2013. Each of these forming belts has the improved forming elements and patterns disclosed herein for producing a spunbond nonwoven web. Although these disclosures by Lindsay, Trokhan, Burazin, and Stage describe belts representative of papermaking belts formed with cured resin on fabric reinforcement members, these belts can be used in the present disclosure with modifications as described herein.
[0063] An example of a forming belt 60 useful in the present disclosure and which can be manufactured according to the disclosure of U.S. Pat. No. 5,514,523 is shown in FIG. 12. As taught herein, a reinforcing member 94 (such as a woven belt of filaments 96) is completely coated with a liquid photopolymer resin to a preselected thickness. A film or negative mask having repeating elements of the desired raised element pattern (e.g., FIG. 14) is juxtaposed over the liquid photopolymer. The resin is then exposed to light of an appropriate wavelength through the film (e.g., ultraviolet light for ultraviolet curable resins). This exposure to light hardens the resin in the exposed areas (i.e., the white or non-printed portions of the mask). The uncured resin (resin under the opaque portions of the mask) is removed from the system, leaving behind the cured resin that forms the pattern shown in the figure (e.g., the cured resin elements 92 shown in FIG. 12). Other patterns can also be formed as described herein.
[0064] Figure 12 shows a portion of a forming belt 60 useful in producing the nonwoven fabric 10 shown in Figure 1. As shown, the forming belt 60 can have cured resin elements 92 on woven strength members 94. The strength members 94 can be formed of woven filaments 96 as is well known in the papermaking belt art, such as resin coated papermaking belts. The cured resin elements can have the general structure shown in Figure 12 and are formed using a mask 97 having the dimensions shown in Figure 14. As shown in the schematic cross-section of FIG. 13, the cured resin elements 92 are "set" to the reinforcing members 94 by being flowed around and cured, and may have a width DW at the distal end of about 0.020 inches to about 0.060 inches, or about 0.025 inches to about 0.030 inches, and an overall height above the reinforcing members 94, referred to as the overburden (OB), of about 0.030 inches to about 0.120 inches, or about 0.50 inches to about 0.80 inches, or about 0.060 inches. FIG. 14 depicts a portion of a mask 97 showing the pattern and representative dimensions of one repeat unit of the repeating heart pattern of the nonwoven fabric 10 shown in FIG. 1. The white areas 98 transmit ultraviolet light, which in the belt manufacturing process described in U.S. Pat. No. 5,514,523 allows the ultraviolet light to cure the underlying resin layer, which is cured to form the raised elements 92 on the reinforcing members 94. After the uncured resin has been washed away, the ends of the belt length are spliced together, which may be determined by the design of the equipment as shown in FIG. 7, to obtain a formed belt 60 having a pattern of cured resin as shown in FIG. 12.
[0065] Similarly, Figure 15 depicts a portion of a mask 97 showing the pattern of one repeat unit of the repeating pattern of nonwoven fabric 10 shown in Figure 2. The white portions 98 transmit UV light, which in the belt manufacturing process allows the UV light to cure the underlying resin layer, which is cured against the reinforcing members 94. After the uncured resin is washed away, the ends of a length of the belt, which may be determined by the design of the equipment as shown in Figure 7, are joined together to produce a formed belt 60 having a cured resin pattern as shown in Figure 16.
[0066] In yet another non-limiting example, Figure 17 depicts a portion of a mask showing the pattern of one repeat unit of the repeating pattern of nonwoven fabric 10 shown in Figure 18. The white portions 98 transmit UV light, which in the belt manufacturing process allows the UV light to cure the underlying resin layer, which is cured against the strength members 94. After the uncured resin is washed away, the ends of the length of fabric 10 are seamed together to produce a formed belt 60 having the cured resin pattern as shown in Figure 18.
[0067] Another example of a portion of a type of forming belt 60 useful in the present disclosure is shown in FIG. 19. The portion of forming belt 60 shown in FIG. 19 is a discrete belt pattern 61 that can have a length L and width W corresponding to the length L and width W of the overall area OA of nonwoven fabric 10. That is, forming belt 60 can have discrete belt patterns 61 (described in more detail below with reference to FIG. 22) each having a discrete belt pattern overall area DPOA corresponding to the overall area OA of nonwoven fabric 10. FIG. 20 represents a portion of a mask showing the pattern of one repeat unit of the repeat pattern of nonwoven fabric 10 shown in FIG. 21. The white portion 98 transmits ultraviolet light, which in the belt manufacturing process allows the ultraviolet light to cure the underlying resin layer, which is cured against reinforcing members 94. After the uncured resin is washed away, both ends of the belt length are spliced together to provide a forming belt 60 having a pattern of cured resin as shown in FIG. 19.
[0068] The portion of the forming belt shown in FIG. 19 illustrates another utility of the present disclosure. The portion of the forming belt 60 shown in FIG. 19 can form the fabric 10 shown in FIG. 21. The nonwoven fabric 10 shown in FIG. 21 can have dimensions of width W and length L, and overall area OA, that make the fabric 10 suitable for use as, for example, a topsheet for a disposable diaper. The nonwoven fabric 10 formed on the forming belt 60 illustrated in FIG. 19 differs from the nonwoven fabric 10 shown in FIGS. 1-3 in that the pattern of three-dimensional formed elements formed by the individual resin elements 92 on the forming belt 60 is not a regular repeating pattern throughout the entire area. Rather, the pattern of three-dimensional raised elements within the overall area DPOA of the individual belt pattern can be described as an irregular pattern that includes different portions called zones. The difference between the zones can be visual, i.e., a visually distinguishable difference, or in the nonwoven fabric 10, the difference can result in a difference in average intensive properties such as basis weight or density, or a combination of visual and intensive properties. A visually distinguishable difference exists when an observer under normal indoor lighting conditions (e.g., 20 / 20 vision, sufficient lighting to read text) can visually distinguish the difference in pattern between areas, such as first area 112 and second area 122.
[0069] The nonwoven fabric 10 can also have visually distinct regions corresponding to the regions of the forming belt. For example, as shown in FIG. 21, the fabric 10 can have at least two, three, or four visually distinct regions. A first region 110 having a first pattern of three-dimensional features and a first average intensive property can have a first region located approximately centrally within the overall area OA. A second region 120 having a second pattern of three-dimensional features and a second average intensive property can have a second region distributed approximately around, and in one embodiment completely surrounding, the first region 110 within the overall area OA. A third region 130 having a third pattern of three-dimensional features and a third average intensive property can have a third region distributed approximately around, and in one embodiment completely surrounding, the second region 120 within the overall area OA. A fourth region 140 having a fourth pattern of three-dimensional features and a fourth average intensive property can have a fourth region, such as the heart pattern shown in Figure 21, located anywhere within the overall area OA, such as the front of the topsheet. In general, there can be n regions, where n is a positive integer. Each of the n regions can have an nth pattern of three-dimensional features, as well as an nth area and an nth average intensive property.
[0070] The visually distinct regions as shown in FIG. 21 can include visually distinct three-dimensional features. These distinct three-dimensional features can be bounded by regions of relatively high density (relative to the interior of the three-dimensional features), which can be in the form of closed figures, such as the heart shapes of FIG. 1 and FIG. 3, and the diamond shapes of FIG. 2 and FIG. 3. In general, as described more fully below, including in relation to the microzones, the three-dimensional features can be defined by a first region and a second region, which are visually distinct, each of which is associated with a common intensive property, and the first region and the second region have a difference in value of the common intensive property. In one embodiment, the three-dimensional features can be defined by a first region and a second region, the first region being at a higher height (dimension measured in the Z direction) than the second region relative to the plane of the first surface. In another embodiment, the three-dimensional feature can be defined by a first region and a second region, the first region being at a higher base than the second region.
[0071] As will be appreciated, the forming belt 60 of the present disclosure allows for the production of a nonwoven material that, instead of having a uniform, constant repeating pattern across the forming belt, can have an irregular repeating of individual belt patterns 61, each similar to the individual belt pattern 61 shown in FIG. 19. Each of the individual belt patterns 61 can be used to form one nonwoven fabric 10 having an overall area OA suitable for use in a disposable absorbent article, such as a diaper or sanitary napkin. The nonwoven fabric 10 can be produced continuously (i.e., in a line) and, if desired, continuously in multiple parallel lanes, each lane being a continuous line of nonwoven fabric 10. The continuous line of nonwoven fabric 10 can be produced in the machine direction along an axis parallel to the machine direction. This nonwoven material can then be slit or otherwise cut to size to produce a nonwoven fabric 10 for use as a topsheet for a disposable absorbent article, such as a diaper or sanitary napkin.
[0072] In one embodiment, the patterns within the overall area DPOA of each individual belt pattern may be the same or different. That is, the consecutively spaced individual belt patterns may be substantially the same, or they may differ in visual appearance and / or in the intensive properties resulting in the nonwoven substrate produced on the belt patterns. For example, as shown diagrammatically in FIG. 22, the pattern of three-dimensional raised elements within the first forming zone 112 of the individual belt pattern 61A may be different from the pattern of three-dimensional raised elements within the first forming zone 112 of the individual belt pattern 61B. In this manner, the forming belt 60 provides flexibility in the manufacture of nonwoven webs 10 suitable for use in consumer products, including disposable absorbent articles. For example, within one package of diapers, the topsheets of at least two diapers may be different because they were produced consecutively by a spunbond process as described herein using consecutive individual belt patterns having different zone patterns. In one embodiment, the nonwoven pattern of the topsheet or backsheet of one size diaper may be different from the nonwoven pattern of the topsheet or backsheet of another size diaper, thereby providing the caregiver with a visual cue as to the size of the diaper. Similarly, the fabric 10 may be used in the topsheet of a sanitary napkin, with the visual pattern of three-dimensional features representing the absorbency of the sanitary napkin. In either case, different patterns of the fabric 10 may be produced on a single belt, with the individual belt patterns being different as desired.
[0073] Thus, the present invention may be described with reference to FIG. 22 as a forming belt having an axis A parallel to a longitudinal direction, which is a machine direction. The forming belt 60 may have a plurality of individual belt patterns 61 arranged in at least one continuous relationship with respect to the longitudinal direction. Each individual belt pattern 61 may have an individual belt pattern total area DPOA defined as a rectangular pattern by a length L and a width W, similar to that shown for individual belt pattern 61A. Each individual belt pattern may have within its total area DPOA a first forming zone 112 having a first pattern of three-dimensional raised elements extending outwardly from the plane of the first surface, and a second forming zone 122 having a second three-dimensional raised elements extending outwardly from the plane of the first surface. The first forming zone may have a first air permeability value and the second forming zone may have a second air permeability value, the first air permeability value being different from the second air permeability value. The patterns within each successively arranged individual belt pattern overall area DPOA may be the same or different.
[0074] By way of example, with reference to the individual belt patterns 61 of the forming belt 60 shown in FIG. 19 and the nonwoven fabric 10 shown in FIG. 21, the following properties were measured. The first region 110 of the nonwoven fabric 10 can have an average basis weight of about 5 gsm to about 30 gsm. The second region 120 can have an average basis weight of about 50 gsm to about 70 gsm, and the third region 130 can have an average basis weight of about 25 gsm to about 60 gsm. The difference in basis weight from region to region can be attributed to the difference in air permeability of the forming belt 60. In an embodiment used to manufacture the nonwoven fabric 10 shown in FIG. 20, where the basis weights of the regions 110, 120, and 130 are 15 gsm, 53 gsm, and 25 gsm, respectively, the air permeability of the respective regions 112, 122, and 132 of the forming belt 60 is 379 cfm, 805 cfm, and 625 cfm, respectively. Thus, by varying the air permeability of each region of the forming belt 10, the intensive properties of the average basis weight and average density of each region can be enhanced across the entire area of the fabric 10.
[0075] As can be seen from the description of the forming belt 60 in FIG. 22 and with reference to FIG. 23, in one embodiment, the nonwoven substrate 11 formed on the belt 60 can be described as a nonwoven substrate 11 having a plurality of portions, described herein as fabrics 10, arranged in at least one continuous relationship with respect to the longitudinal direction, i.e., machine direction, when formed on the forming belt 60. FIG. 23 is a schematic diagram of a spunbond nonwoven substrate 11 showing continuously arranged fabrics 10, each having a different pattern in different regions. Each fabric 10 can have an overall area OA defined by a length L and a width W in a rectangular pattern. Each arranged fabric 10 in turn can have within its overall area OA at least a first region 110 having a first pattern of three-dimensional features and a first average intensive property and a first region located within the overall area OA, and a second region 120 having a second pattern of three-dimensional features and a second average intensive property and a second region located within the overall area OA. Optionally, there may be additional regions, such as a third region 130 having a third pattern of three-dimensional features and a third average intensive property and a third area within the overall area OA. As shown in the exemplary schematic diagram of Figure 23, the first pattern 110A of the fabric 10A may be different from the first pattern 110B of the fabric 10B and may be different from the first pattern 110C of the fabric 10C. The same is true for the second regions 120A, 120B, and 120C.
[0076] In general, the consecutively arranged nonwoven webs 10 of the nonwoven material 11 formed on the forming belt 60 may differ in their overall area, intensive properties, and visual appearance. A common intensive property is an intensive property possessed by a plurality of zones (for a zoned pattern as shown in FIG. 21) or regions (for a three-dimensional feature such as a regular repeating pattern as shown in FIG. 1). Such intensive properties of the nonwoven web 10 may be average values and may include, but are not limited to, density, volume density, basis weight, thickness, and opacity. For example, if density is a common intensive property of two different zones or regions, the density value of one zone or region may be different from the density value of the other zone or region. Zones (such as, for example, a first zone and a second zone) may be identifiable regions that can be distinguished from each other visually and by different intensive properties averaged within the zones.
[0077] Once manufactured, the individual nonwoven fabrics 10 can be cut to size and used for their intended purpose, such as, for example, a topsheet for a disposable absorbent article. For example, a disposable diaper 1006 is shown in a flat, laid-out orientation in FIG. 24. A single fabric 10 is cut to the appropriate overall area and adhered to the diaper 1006 by means well known in the art. The fabric 10 may be cut prior to being assembled into the diaper 1006, or the nonwoven substrate 11 may be integral with other components of the diaper in the form of a web during the diaper manufacturing process and cut to size after assembly.
[0078] As can be seen with reference to Figure 24, in one embodiment, the nonwoven substrate 11 formed on the belt 60 can be described as a nonwoven substrate 11 having a plurality of portions, described herein as fabrics 10, arranged in at least one continuous relationship relative to the length (i.e., machine direction when formed on the forming belt 60) and at least one side-by-side relationship (i.e., transverse direction when formed on the forming belt 60). Figure 24 is a schematic diagram of a spunbond nonwoven substrate 11 showing fabrics 10 arranged in succession in adjacent machine direction lanes 13, adjacent lanes having side-by-side respective fabrics 10, designated 10D, 10E, and 10F in Figure 24. Each fabric 10 can have an overall area OA defined by a length L and a width W in a rectangular pattern. Each sequentially arranged fabric 10 can have within its overall area OA at least a first region 110 having a first pattern of three-dimensional features and a first average intensive property and a first region located within the overall area OA, and a second region 120 having a second pattern of three-dimensional features and a second average intensive property and a second region located within the overall area OA. Optionally, there can be additional regions, such as a third region 130 having a third pattern of three-dimensional features and a third average intensive property and a third region within the overall area OA. Each fabric 10 in the side-by-side lanes can be substantially the same, or each fabric 10 can differ in terms of size, visual appearance, and / or intensive property. After production, the nonwoven substrate 11 can be wound and then slit into each lane and processed into a consumer product, or slit and then wound.
[0079] As a representative sample for comparing the basis weight difference between a fabric 10 formed in a regular repeating uniform pattern and a fabric 10 formed in a non-uniform zonal pattern, the nonwoven fabric 10 of Example 1 was compared to a fabric having a pattern similar to that shown in FIG. 21, designated Example 3. Example 3 is a bicomponent spunbond nonwoven web produced in the apparatus disclosed herein by spinning a polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) in a 50:50 ratio into the form of trilobal fibers. The spunbond bicomponent trilobal fibers were spun onto a forming belt 60 moving at a linear speed of about 25 m / min, with the forming belt having a zonal pattern as shown in FIG. 19, at a rate of 30 g / m2. 2 A second substrate was formed under the same conditions, but with at least one portion having the regular repeating uniform pattern on the forming belt shown in Figure 16 from which the basis weight was determined. The fiber spinning conditions, throughput, forming belt line speed, and compression roll bonding temperature were the same for both substrates.
[0080] Example 3 A polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) were mixed in a 50:50 ratio in the form of trilobal fibers at 30 g / m 2 A bicomponent spunbond nonwoven fabric was produced by spinning the fibers to an average basis weight of 1.2 g / cm. The nonwoven fabric was produced as described in connection with Figures 7 and 8 on a forming belt moving at a linear speed of about 25 m / min to form a fabric having a zoned pattern as shown in Figure 20. The fibers of the fabric were further bonded on first surface 12 by compression rolls 70, 72 heated to 130°C, and the fabric was wound on a reel in winder 75.
[0081] Example 4 A polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) were mixed in a 50:50 ratio in the form of trilobal fibers at 30 g / m 2 A bicomponent spunbond nonwoven fabric was produced by spinning the fibers to an average basis weight of 1.2 g / cm. The nonwoven fabric was produced as described in connection with Figures 7 and 8 on a forming belt moving at a linear speed of about 25 m / min to form a fabric having a repeating (non-zoned) pattern as shown in Figure 2. The fibers of the fabric were further bonded on first surface 12 by compression rolls 70, 72 heated to 130°C and wound on reels in winder 75.
[0082] Table 2 below shows the average local basis weights measured according to the Local Basis Weight Test Method herein and averaged over 10 samples. The samples for measurement were taken from the fabric shown in Figures 25A and 25B. In Figures 25A and 25B, the black rectangles represent 3 cm 2 26 is a cut section of a sample of fabric. As can be seen, the fabric is labeled as AE across the cross direction (CD). The measurements show that there is a significant difference in basis weight between each zone of the zoned fabric, as well as in the CD distribution, as shown graphically in FIG. 26.
[0083] [Table 2]
[0084] As can be seen from Table 2, fabrics 10 formed on forming belt 60 having regions of differing air permeability exhibit greater variation in fiber load, and therefore basis weight, in the CD direction of nonwoven fabric 10, indicating that the fibers can migrate with air to the regions of higher permeability. Fabrics 10 with a non-regionalized, regular repeating pattern exhibit generally the same basis weight in the CD direction of the fabric.
[0085] In addition to the difference in air permeability of different regions of the forming belt 60, the construction of the forming belt 60 can also affect other intensive properties of the regions of the fabric 10, such as average caliper, average softness, average compression resistance, and fluid absorption characteristics.
[0086] Another aspect of the invention relates to spunbond commercial lines where multiple beams are used to increase the laydown opacity and uniformity of the fabric. In some cases, the system may include three spunbond beams (known in the art as "SSS") and may be combined with a meltblown process (M) in a system known as an "SSMMS" spunbond line.
[0087] Calendering the nonwoven fabric 10 to have point bonds 90 can reduce fuzzing. Fuzzing refers to the tendency of fibers to fray and separate from the fabric 10. Fraying and separation can occur due to frictional engagement with manufacturing equipment during the manufacture of disposable absorbent articles, or with another surface, such as a person's skin, that contacts the fabric 10. In some applications, such as in the topsheet of a disposable absorbent article, fuzzing is a negative consumer phenomenon. However, bonding fibers in place can also be a negative for the consumer because it can create roughness on an otherwise soft nonwoven substrate surface. The inventors have anticipated and found that the nonwoven substrates and nonwoven fabrics of the present disclosure allow for increased bonding (and therefore reduced fuzzing) with minimal loss of softness. Bonding can be achieved by relatively closely spaced point bonds 90, the spacing of which is determined by the degree of fuzz reduction desired. Bonding can also be done by known methods for chemically or thermally bonding nonwoven fibers, such as heat bonding, ultrasonic bonding, pressure bonding, bonding with latex adhesives, and combinations of these methods. The reduction of fuzzing by bonding is described below with respect to Examples 5 and 6.
[0088] Example 5 A polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) were mixed in a 50:50 ratio in the form of trilobal fibers at a rate of about 30 g / m on the forming belt described with reference to Figures 7 and 8 moving at a linear speed of about 25 m / min. 2 to form a fabric having a repeating pattern as shown in Figure 36. The fibers of the fabric were further bonded to first surface 12 by compression rolls 70, 72 with compression roll 70 heated to 130°C to form a substantially continuous bond 80.
[0089] Example 6 A polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) were mixed in a 50:50 ratio in the form of trilobal fibers at a rate of about 30 g / m on the forming belt described with reference to Figures 7 and 8 moving at a linear speed of about 25 m / min. 2 A bicomponent spunbond nonwoven fabric was produced by spinning the yarn to an average basis weight of 1.25 mm to form a fabric having a repeating pattern as described with respect to FIG. 37. The fibers of the fabric were further bonded to the first surface 12 by compression rolls 70, 72 with compression roll 70 heated to 130° C. to form a substantially continuous bond 80. The fibers of the fabric were further calendered in calender rolls 71, 73, where roll 73 was an engraved roll with a 10% point bond pattern of raised portions 88 in the form of pins with a pin height of 1.25 mm and an open gap of 0.62 mm. Roll 73 was heated to 135° C. to form point bonds 90 on the second surface 14 of the fabric 10 as shown in FIG.
[0090] The fabrics 10 of Examples 5 and 6 differed only in the absence or presence of point bonds 90. The second side 14 of the fabric 10 was subjected to a fuzz test according to the Fuzz Test to determine the effectiveness of the point bonds in securing the fibers to the surface of the fabric. The results of the fuzz test for Examples 5 and 6 are shown in Table 3.
[0091] [Table 3]
[0092] As shown above, the point bonds 90 significantly reduce the MD fuzz value. Despite the bonding process, the softness, absorbency, and aesthetics are unexpectedly maintained, and in this case, the fuzz resistance is also desirable during consumer use. The absorbent articles of the present disclosure are typically placed in a package for delivery, storage, and sale. The package may include polymeric films and / or other materials. Graphics and / or indicia related to the absorbent article's characteristics may be formed, printed, positioned, and / or located on the exterior portion of the package. Each package may include multiple absorbent articles. The absorbent articles may be packaged under compression to reduce the size of the package while still providing a reasonable amount of absorbent articles per package. Packaging the absorbent articles under compression allows caregivers to easily handle and store the package, while providing manufacturers with reduced distribution costs due to the size of the package. FIG. 27 shows an exemplary package 1000 including multiple absorbent articles 1004. The package 1000 defines an interior space 1002 in which a plurality of absorbent articles 1004 are placed. The plurality of absorbent articles 1004 are arranged in one or more stacks 1006.
[0093] According to the in-bag stack height test described herein, a package of absorbent articles of the present disclosure may have an in-bag stack height of less than about 100 mm, less than about 95 mm, less than about 90 mm, less than about 85 mm, less than about 85 mm but greater than about 75 mm, less than about 80 mm, less than about 78 mm, less than about 76 mm, or less than about 74 mm, specifically all increments of 0.1 mm within the specified range and all ranges therein or formed thereby. Alternatively, according to the in-bag stack height test described herein, a package of absorbent articles of the present disclosure may have an in-bag stack height of about 70 mm to about 100 mm, about 70 mm to about 95 mm, about 72 mm to about 85 mm, about 72 mm to about 80 mm, or about 74 mm to about 78 mm, specifically all increments of 0.1 mm within the specified range and all ranges therein or formed thereby.
[0094] Overview of absorbent articles The three-dimensional nonwoven fabric 10 of the present disclosure can be used as a component of absorbent articles such as diapers, pediatric care products such as training pants, feminine care products such as sanitary napkins, and adult care products such as incontinence products, pads, and pants. An example of an absorbent article in the form of a diaper 220 is shown in FIGS. 28-30. FIG. 28 is a plan view of an exemplary diaper 220 laid out flat with portions of the diaper 220 cut away to more clearly show the structure of the diaper 220. The wearer-facing surface of the diaper 220 in FIG. 28 faces the observer. The diaper 220 is shown for illustrative purposes only, as the three-dimensional nonwoven material of the present disclosure can be used as one or more components of an absorbent article, such as a topsheet, an acquisition layer, a topsheet and an acquisition layer, or a topsheet and an acquisition and / or the distribution system ("ADS"). In any case, the three-dimensional nonwoven material of the present disclosure can be liquid permeable.
[0095] The absorbent article 220 may include a liquid permeable material or topsheet 224, a liquid impermeable material or backsheet 225, an absorbent core 228 positioned at least partially intermediate the topsheet 224 and the backsheet 225, and barrier leg cuffs 234. The absorbent article may also include an ADS 250, which in the illustrated example includes a distribution layer 254 and an acquisition layer 252, which are described in more detail below. The absorbent article 220 may also include elastic gasket cuffs 232, which typically include elastic bodies 233 that are joined to the chassis of the absorbent article through the topsheet and / or backsheet and are substantially planar to the diaper chassis.
[0096] 28 and 31 also show typical taped diaper components, such as a fastening system with tabs 242 attached toward the rear edge of the article and cooperating with a landing area 244 at the front of the absorbent article. The absorbent article may also include other typical elements not shown, such as, for example, a rear elastic waist feature, a front elastic waist feature, lateral barrier cuff(s), and / or a lotion application.
[0097] The absorbent article 220 comprises a front waist edge 210, a back waist edge 212 longitudinally opposite the front waist edge 210, a first side edge 203, and a second side edge 204 laterally opposite the first side edge 203. The front waist edge 210 is the edge of the article intended to be placed towards the front of the user when worn, and the back waist edge 212 is the opposing edge. The absorbent article 220 may have a longitudinal axis 280 that extends from a lateral midpoint of the front waist edge 210 to a lateral midpoint of the back waist edge 212 of the article, and divides the article into two halves that are substantially symmetrical with respect to the longitudinal axis 280, when the article is laid flat and viewed from above as in FIG. The absorbent article 220 may also have a transverse axis 290 that extends from a longitudinal midpoint of the first side edge 203 to a longitudinal midpoint of the second side edge 204. The length L of the article may be measured from the front waist edge 210 to the back waist edge 212 along the longitudinal axis 280. The width W of the absorbent article may be measured along the transverse axis 290 from the first side edge 203 to the second side edge 204. The absorbent article may include a crotch point C, defined herein as a point located on the longitudinal axis starting from the front edge 210 of the article 220 and two-fifths (2 / 5) of L. The article may comprise a front waist region 205, a back waist region 206, and a crotch region 207. The front waist region 205, the back waist region 206, and the crotch region 207 may each define 1 / 3 of the longitudinal length L of the absorbent article.
[0098] The topsheet 224, backsheet 225, absorbent core 228, and other components of the article may be assembled in a variety of configurations, particularly by, for example, gluing or heat embossing.
[0099] The absorbent core 228 may include an absorbent material that includes at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% by weight of superabsorbent polymer, and a core wrap that encloses the superabsorbent polymer. The core wrap may typically include two materials, a substrate, or a nonwoven material 216 on the top side of the core and a nonwoven material 216' on the bottom side. These types of cores are known as airfelt-free cores. The core may include one or more channels, shown in FIG. 28 as four channels 226, 226' and 227, 227'. The channels 226, 226', 227, and 227' are optional features. Instead, the core may have no channels at all or any number of channels.
[0100] These and other components of the exemplary absorbent article are discussed in more detail below.
[0101] Top sheet In the present disclosure, the topsheet (the portion of the absorbent article that contacts the wearer's skin and receives fluid) can be formed of a portion or all of one or more three-dimensional nonwoven materials described herein and / or have one or more nonwoven materials positioned thereon and / or joined thereto, whereby the nonwoven material(s) contact the wearer's skin. Other portions of the topsheet (other than the three-dimensional nonwoven material) may also contact the wearer's skin. The three-dimensional nonwoven material may be positioned as a strip or patch on the upper surface of a typical topsheet 224. Alternatively, the three-dimensional nonwoven material may form only the central CD region of the topsheet. The central CD region may extend to the entire MD length of the topsheet or less than the entire MD length of the topsheet.
[0102] The topsheet 224 may be joined to the backsheet 225, the absorbent core 228, and / or any other layers as is known in the art. Typically, the topsheet 224 and the backsheet 225 are directly joined to one another at some locations (e.g., at or near the periphery of the absorbent article) and are indirectly joined at other locations by directly joining the topsheet and backsheet to one or more other elements of the article 220.
[0103] The topsheet 224 may be compliant, soft-feeling, and non-irritating to the wearer's skin. Further, a portion or all of the topsheet 224 may be liquid permeable, permitting liquids to readily penetrate through its thickness. Further, a portion or all of the topsheet 224 may be treated with a surfactant or other agent to render the web hydrophilic or hydrophobic. Any portion of the topsheet 224 may be coated with a lotion and / or skin care composition as generally disclosed in the art. The topsheet 224 may also include or be treated with an antimicrobial agent.
[0104] Back sheet The backsheet 225 is generally that portion of the absorbent article 220 that is positioned adjacent the garment-facing surface of the absorbent core 228 and prevents or at least inhibits fluids and bodily exudates absorbed and contained therein from soiling articles such as bed sheets and undergarments. The backsheet 225 is typically impermeable, or at least substantially impermeable, to fluids (e.g., urine). The backsheet may be or include a thin plastic film, such as, for example, a thermoplastic film having a thickness of about 0.012 mm to about 0.051 mm. Other suitable backsheet materials include breathable materials that prevent or at least impede fluids from passing through the backsheet 225 while allowing vapors to escape from the absorbent article 220.
[0105] The backsheet 225 may be joined to the topsheet 224, the absorbent core 228, and / or any other elements of the absorbent article 220 by any attachment method known to those of skill in the art.
[0106] The absorbent article may have a backsheet that includes an outer cover or outer cover nonwoven. The outer cover or outer cover nonwoven of the absorbent article 220 may cover at least a portion or all of the backsheet 225 to form the soft, garment-facing surface of the absorbent article. The outer cover or outer cover nonwoven may be formed from a high-loft three-dimensional nonwoven material as described herein. Alternatively, the outer cover or outer cover nonwoven may include one or more known outer cover materials. When the outer cover includes one of the three-dimensional nonwoven materials of the present disclosure, the three-dimensional nonwoven material of the outer cover may or may not match (e.g., same material, same pattern) the three-dimensional nonwoven material used as the topsheet or as the topsheet and acquisition layer of the absorbent article. In other cases, the outer cover may have a printed or otherwise applied pattern that matches or visually resembles the pattern of the three-dimensional nonwoven material used as the topsheet or as the topsheet and acquisition layer laminate of the absorbent article. The outer cover may be joined to at least a portion of the backsheet 225 by mechanical, ultrasonic, thermal, adhesive, or other suitable attachment methods.
[0107] Absorbent Core The absorbent core is the component of the absorbent article that has the highest absorbent capacity and includes the absorbent material and the core wrap or core bag that encloses the absorbent material. The absorbent core does not include the acquisition and / or distribution system or any other components of the absorbent article that are not an integral part of or disposed within the core wrap or core bag. The absorbent core may include, consist essentially of, or consist of the core wrap, the absorbent materials described above (e.g., superabsorbent polymers with little or no cellulose fibers), and size agents.
[0108] The absorbent core 228 may include an absorbent material having a large amount of superabsorbent polymer (abbreviated herein as "superabsorbent polymer, SAP") encapsulated within a core wrap. The SAP content may comprise 70%-100%, or at least 70%, 75%, 80%, 85%, 90%, 95%, 99%, or 100% by weight of the absorbent material contained in the core wrap. The core wrap is not considered an absorbent material for purposes of assessing the percentage of SAP in the absorbent core. The absorbent core may include airfelt with or without superabsorbent polymer.
[0109] By "absorbent material" is meant materials that have some absorbent or liquid retention properties, such as SAP, cellulosic fibers, and synthetic fibers. Typically, sizes used in making absorbent cores have no or little absorbent properties and are not considered absorbent materials. The SAP content can be greater than 80% by weight, such as at least 85%, at least 90%, at least 95%, at least 99%, or even up to 100% by weight of the absorbent material contained within the core wrap. This airfelt-free core is relatively thin compared to conventional cores that typically contain 40-60% SAP and a high content of cellulosic fibers. The absorbent material may contain less than 15% by weight, or less than 10%, less than 5%, less than 3%, less than 2%, less than 1%, or even substantially no natural cellulosic and / or synthetic fibers, among others.
[0110] With reference to the above, airfelt-free cores with little or no natural, cellulosic and / or synthetic fibers are much thinner than conventional cores, which makes the overall absorbent article thinner than absorbent articles with cores containing mixed SAP and cellulosic fibers (e.g., 40-60% cellulosic fibers). This thinness of the core may lead to a consumer perception of reduced absorbency and performance, which is technically not the case. Currently, these thin cores are typically used with substantially planar or perforated topsheets. Furthermore, absorbent articles with these thin airfelt-free cores have reduced capillary void space due to the presence of little or no natural, cellulosic or synthetic fibers in the core. Thus, sometimes there may not be enough capillary void space in the absorbent article to fully accommodate multiple insults or one large insult of bodily waste.
[0111] To solve such problems, the present disclosure provides absorbent articles that combine these thin airfelt-free cores with any of the high loft three-dimensional nonwoven materials described herein as topsheets or topsheet and acquisition layer laminates. In such cases, the consumer perception of absorbency and performance is improved through the increased thickness of the absorbent article due to the additional thickness provided by the high loft three-dimensional nonwoven materials. Furthermore, the three-dimensional nonwoven materials, when used with these thin airfelt-free cores as topsheets or topsheet and acquisition layer laminates, provide cost savings to consumers and manufacturers by allowing for a minimum stack height while again adding capillary void space to the absorbent article. In this way, the absorbent articles of the present disclosure can easily absorb multiple discharges or one large discharge due to this increased capillary void space. Additionally, absorbent articles that include a nonwoven material as a topsheet or a laminate of a topsheet and an acquisition layer provide consumers with an aesthetically pleasing topsheet of increased thickness and therefore consumer perception of absorbency and performance compared to planar or apertured topsheets.
[0112] An exemplary absorbent core 228 of the absorbent article 220 of Figures 31-32 is shown alone in Figures 33-35. The absorbent core 228 may comprise a front side 480, a back side 282, and two longitudinal sides 284, 286 joining the front side 480 and the back side 282. The absorbent core 228 may also comprise a generally planar top side and a generally planar bottom side. The front side 480 of the core is the side of the core that is intended to be positioned towards the front waist edge 210 of the absorbent article. The core 228 may have a longitudinal axis 280' that substantially corresponds to the longitudinal axis 280 of the absorbent article 220 when viewed from above in a top plan view as shown in Figure 28. In certain absorbent articles, greater absorbency may be required at the front side, so the absorbent material may be distributed in greater amounts toward the front side 480 than toward the back side 282. The front side 480 and back side 282 of the core may be shorter than the longitudinal sides 284 and 286 of the core. The core wrap may be formed of two nonwoven materials, substrates, laminates, or other materials 216, 216' that may be at least partially sealed along the sides 284, 286 of the absorbent core 228. The core wrap may be at least partially sealed along its front side 480, back side 282, and two longitudinal sides 284, 286 such that substantially no absorbent material leaks out of the absorbent core wrap. As shown in FIG. 34, a first material, substrate, or nonwoven 216 may at least partially surround a second material, substrate, or nonwoven 216' to form the core wrap. The first material 216 may surround a portion of the second material 216 ′ proximate the first side edge 284 and the second side edge 286 .
[0113] The absorbent core may include an adhesive, for example, to help prevent movement of the SAP within the core wrap and / or to ensure the integrity of the core wrap, especially if the core wrap is made from two or more substrates. The adhesive may be, for example, a hot melt adhesive supplied by HB Fuller. The core wrap may extend over a larger area than strictly necessary to accommodate the absorbent material therein.
[0114] The absorbent material may be a continuous layer present within the core wrap. Alternatively, the absorbent material may consist of individual pockets or stripes of absorbent material enclosed within the core wrap. In the first case, the absorbent material may be obtained, for example, by applying a single continuous layer of absorbent material. A continuous layer of absorbent material, in particular of SAP, may also be obtained by combining two absorbent layers with a discontinuous absorbent material application pattern, the resulting layer being substantially continuously distributed throughout the absorbent granular polymer material area, as disclosed, for example, in US Patent Application Publication No. 2008 / 0312622 (A1) (Hundorf). The absorbent core 228 may comprise a first absorbent layer and a second absorbent layer. The first absorbent layer may comprise a first material 216 and a first layer 261 of absorbent material, which may be up to 100% SAP. The second absorbent layer may comprise a second material 216' and a second layer of absorbent material 262, which may also be up to 100% SAP. The absorbent core 228 may also include a fibrous thermoplastic adhesive material 251 at least partially bonding each layer of absorbent material 261, 262 to the corresponding material 216 or 216', respectively. This is illustrated by way of example in Figures 34-35, in which the first and second SAP layers are applied as transverse stripes or "land areas" that have the same width as the desired absorbent material deposition area on the respective substrates before being combined. The stripes may include different amounts of absorbent material (SAP) to provide a profiled basis weight along the longitudinal axis of the core 280. The first material 216 and the second material 216' may form a core wrap.
[0115] The fibrous thermoplastic adhesive material 251 may be in at least partial contact with the absorbent material 261, 262 in the land areas and may be in at least partial contact with the material 216, 216' in the bond area, thereby imparting an essentially three-dimensional structure to the fibrous layer of thermoplastic adhesive material 251 which is itself an essentially two-dimensional structure of relatively small thickness compared to its length and width dimensions. The fibrous thermoplastic adhesive material may thereby provide cavities that cover the land areas of the absorbent material, thereby immobilizing this absorbent material, which may be up to 100% SAP.
[0116] The thermoplastic adhesive used in the fibrous layer may have elastomeric properties such that the web formed by the fibers on the SAP layer can be stretched as the SAP swells.
[0117] Superabsorbent Polymer (SAP) SAPs useful in the present disclosure can include a variety of water-swellable polymers that are water insoluble but capable of absorbing large amounts of fluid.
[0118] The superabsorbent polymer may be in particulate form so that it is flowable in the dry state. The particulate absorbent polymer material may be made of poly(meth)acrylic acid polymers. However, starch-based particulate absorbent polymer materials may also be used, as well as polyacrylamide copolymers, ethylene maleic anhydride copolymers, cross-linked carboxymethylcellulose, polyvinyl alcohol copolymers, cross-linked polyethylene oxide, and starch graft copolymers of polyacrylonitrile.
[0119] SAP may be in a variety of shapes. The term "particle" refers to granules, fibers, flakes, spheres, powders, platelets, and other shapes and forms of superabsorbent polymer particles known to those skilled in the art. SAP particles may be in the shape of fibers, i.e., elongated, acicular superabsorbent polymer particles. Fibers may also be in the form of long filaments that may be woven. SAP may be spherical particles. The absorbent core may contain one or more types of SAP.
[0120] For most absorbent articles, and particularly for diapers, liquid discharge from the wearer occurs primarily in the front half of the absorbent article. Thus, the front half of the article (defined by the area between the front edge and a transverse line located half a distance L from the front waist edge 210 or the back waist edge 212) may comprise the majority of the absorbent capacity of the core. Thus, at least 60% of the SAP, or at least 65%, 70%, 75%, 80%, or 85% of the SAP may be present in the front half of the absorbent article, with the remaining SAP located in the rear half of the absorbent article. Alternatively, the distribution of SAP may be uniform throughout the core, or may have any other suitable distribution.
[0121] Additionally, the total amount of SAP present in the absorbent core may further vary depending on the intended user. A diaper for a newborn may require less SAP compared to an infant, toddler, or adult incontinence diaper. The amount of SAP in the core may be about 5-60 g, or 5-50 g. The average SAP basis weight within the SAP deposition area 8 (or of "at least one" deposition area 8, if multiple are present) is at least 50, 100, 200, 300, 400, 500 g / m 2 , or more. The area of the channels (eg, 226, 226', 227, 227') present in the absorbent material deposition area 8 is extrapolated from the absorbent material deposition area to calculate this average basis weight.
[0122] Core Wrap The core wrap may be formed of a single substrate, material, or nonwoven folded around the absorbent material, or may include two (or more) substrates, materials, or nonwovens attached to one another. A common method of attachment is the so-called C-wrap and / or sandwich wrap. In a C-wrap, the longitudinal and / or lateral edges of one substrate are folded over the other substrate to form flaps, as shown, for example, in Figures 29 and 34. These flaps are then bonded, typically by glue adhesion, to the outer surface of the other substrate.
[0123] The core wrap may be formed of any material suitable for receiving and containing absorbent material. Common substrate materials used to produce conventional cores may be used, particularly paper, tissue, film, woven or nonwoven fabrics, or laminates or composites of any of these.
[0124] The substrate may also be breathable (in addition to being liquid or fluid permeable). Thus, the films useful herein may contain micropores.
[0125] The core wrap may be at least partially sealed along all sides of the absorbent core such that substantially no absorbent material escapes from the core. By "substantially free of absorbent material" it is meant that less than 5%, less than 2%, less than 1%, or about 0% by weight of absorbent material escapes from the core wrap. The term "seal" should be understood broadly. The seal need not be continuous along the entire periphery of the core wrap, but may be discontinuous along some or all of it, such as formed by a series of seal points spaced apart in a line. The seal may be formed by gluing and / or thermal bonding.
[0126] When the core wrap is formed by two substrates 216, 216', four seals may be used to encapsulate the absorbent material 260 within the core wrap. For example, the first substrate 216 may be disposed on one side of the core (shown as the top side in Figs. 33-35) and extends around the longitudinal edge of the core to at least partially encapsulate the opposing bottom side of the core. The second substrate 216' may be between the encapsulated flaps of the first substrate 216 and the absorbent material 260. The flaps of the first substrate 216 may be glued to the second substrate 216' to provide a strong seal. This so-called C-wrap construction may provide advantages such as improved burst resistance under wet load conditions compared to sandwich style seals. The front and back sides of the core wrap may then also be sealed by gluing the first and second substrates together to provide complete encapsulation of the absorbent material around the entire perimeter of the core. For the front and rear sides of the core, the first and second substrates may extend and be joined to each other in a substantially planar direction to form a so-called sandwich structure at these edges. In the so-called sandwich structure, the first and second substrates may also extend outwardly on all sides of the core and be sealed flat or substantially flat along all or part of the periphery of the core, typically by gluing and / or heat / pressure bonding. In one example, the first and second substrates may be cut into a rectangle for ease of manufacture since neither the shape needs to be molded, although other shapes are within the scope of the present disclosure.
[0127] The core wrap may also be formed by a single substrate that encloses the absorbent material in a wrapping manner and can be sealed along the front and back sides of the core as well as one longitudinal seal.
[0128] SAP deposition area The absorbent material deposition area 208 may be defined by the periphery of the layer formed by the absorbent material 260 within the core wrap, as seen from the top side of the absorbent core. The absorbent material deposition area 208 may have various shapes, in particular a so-called "dogbone" or "hourglass" shape, tapering along its width towards the center or "crotch" region of the core. Thus, the absorbent material deposition area 8 may have a relatively narrow width in the area of the core intended to be placed in the crotch region of the absorbent article, as illustrated in FIG. 28. This may provide greater comfort when worn. The absorbent material deposition area 8 may also be generally rectangular, for example, as shown in FIGS. 31-33, although other deposition areas, such as rectangular, "T", "Y", "hourglass" or "dogbone" shapes, are within the scope of the present disclosure. The absorbent material may be deposited using any suitable technique that may allow for relatively precise deposition of SAP at a relatively high speed.
[0129] channel The absorbent material deposition area 208 may comprise at least one channel 226 oriented at least partially in the longitudinal direction of the article 280 (i.e., having a longitudinal vector component), as shown in Figures 28 and 29. Other channels may be oriented at least partially in the transverse direction (i.e., having a transverse vector component), or in any other direction. Hereinafter, when "channel" is used in the plural, it means "at least one channel". The channel may have a length L' that is at least 10% of the length L of the article, projecting on the longitudinal axis 280 of the article. The channel may be formed in various ways. For example, the channel may be formed by an area in the absorbent material deposition area 208 that may be substantially free or completely free of absorbent material, in particular SAP. In another example, the channel may be formed in an area in the absorbent material deposition area 208 where the absorbent material of the core comprises cellulose, airfelt, SAP, or a combination thereof, and the channel may be substantially free or completely free of absorbent material, in particular SAP, cellulose, or airfelt. Additionally or alternatively, the channels may also be formed by continuously or discontinuously bonding the top side of the core wrap to the bottom side of the core wrap via the absorbent material deposition area 208. The channels may be continuous, although it is also contemplated that the channels may be intermittent. The acquisition-distribution system or layer 250, or another layer of the article, may further comprise channels that may or may not correspond to the channels of the absorbent core.
[0130] In some cases, as shown in Figure 28 by two longitudinally extending channels 226, 226', the channels may be at least as longitudinal height as the crotch point C or lateral axis 260 of the absorbent article. The channels may also extend from the crotch region 207 or may be in the front waist region 205 and / or back waist region 206 of the article.
[0131] The absorbent core 228 may also comprise more than two channels, e.g., at least three, at least four, at least five, at least six, or more. Shorter channels may also be present, e.g., in the rear waist region 206 or the front waist region 205 of the core, as represented by the pair of channels 227, 227' in Figure 28 toward the front of the article. The channels may comprise one or more pairs of channels arranged symmetrically or otherwise disposed relative to the longitudinal axis 280.
[0132] Channels may be particularly useful in absorbent cores when the absorbent material deposition areas are rectangular, as the channels may improve the flexibility of the core to an extent that would make it disadvantageous to use a non-rectangular (shaped) core. Of course, channels may also be present in SAP layers having shaped deposition areas.
[0133] The channels may be entirely longitudinally oriented, parallel to the longitudinal axis, or entirely transversely oriented, parallel to the transverse axis, but may be at least partially curved.
[0134] To reduce the risk of fluid leakage, the longitudinal main channel may not extend to any edge of the absorbent material deposition area 208 and may therefore be fully enclosed within the core absorbent material deposition area 208. The minimum distance between the channel and the nearest edge of the absorbent material deposition area 208 may be at least 5 mm.
[0135] The channel may have a width Wc along at least a portion of its length, e.g., at least 2 mm, at least 3 mm, at least 4 mm, up to, e.g., 20 mm, 16 mm, or 12 mm. The width of the channel may be constant over substantially the entire length of the channel, or may vary along its length. If the channel is formed by an area of no absorbent material in the absorbent material deposition region 208, the width of the channel is considered to be the width of the area of no material, ignoring any core wrap that may be present in the channel. If the channel is not formed by an area of no absorbent material, e.g., formed primarily by the joining of the core wrap through the absorbent material area, the width of the channel is the width of this join.
[0136] At least some or all of the channels may be permanent channels, meaning that their integrity is at least partially maintained in both dry and wet conditions. Permanent channels may be obtained by providing one or more adhesive materials, such as, for example, a fibrous layer of adhesive material or a structural glue, which helps to bond the substrate with the absorbent material within the walls of the channel. Permanent channels may also be formed by bonding the upper and lower sides of the core wrap (e.g., the first substrate 216 and the second substrate 216') and / or the topsheet 224 and the backsheet 225 to each other throughout the channel. Typically, adhesives are used to bond the sides of the core wrap, or the topsheet and the backsheet through the channel, although bonding by other known processes such as compression bonding, ultrasonic bonding, thermal bonding, or combinations thereof are also possible. The core wrap, or the topsheet 224 and the backsheet 225 may be bonded continuously or intermittently along the channel. When the absorbent article is completely filled with fluid, the channels may advantageously remain or become visible at least through the topsheet and / or backsheet. This may be obtained by making the channels substantially free of SAP so that they do not swell, and large enough so that they do not close when wet. Additionally, it may be advantageous to bond the core wrap to itself or the topsheet to the backsheet throughout the channels.
[0137] Barrier Leg Cuffs The absorbent article may include a pair of barrier leg cuffs 34. Each barrier leg cuff may be formed by a piece of material adhered to the absorbent article, so that it can extend upward from the wearer-facing surface of the absorbent article and provide improved containment of liquids and other exudates near the junction of the wearer's torso and legs. The barrier leg cuffs may be bounded by a proximal edge 64 that is joined directly or indirectly to the topsheet 224 and / or backsheet 225, and a free edge 266 that is intended to contact and form a seal with the wearer's skin. The barrier leg cuffs 234 extend at least partially between the front waist edge 210 and the back waist edge 212 of the absorbent article on both sides of the longitudinal axis 280, and are at least at the level of the crotch point (C) or crotch region. The barrier leg cuff may be joined to the chassis of the article at a proximal edge 264 by a bond 265, which may be made by a combination of gluing, melt bonding, or other suitable bonding processes. The bond 265 at the proximal edge 264 may be continuous or intermittent. The bond 265 closest to the raised section of the leg cuff defines the proximal edge 264 of the riser section of the leg cuff.
[0138] The barrier leg cuffs may be integral with the topsheet 224 or backsheet 225 or may be separate pieces of material joined to the chassis of the article. Each barrier leg cuff 234 may include one, two or more elastic strings 235 near its free edge 266 to provide a better seal.
[0139] In addition to the barrier leg cuffs 234, the article may comprise gasket cuffs 232 joined to the chassis of the absorbent article, particularly the topsheet 224 and / or backsheet 225, and positioned outwardly relative to the barrier leg cuffs. The gasket cuffs 232 may provide a more effective seal around the wearer's thighs. Each gasket leg cuff may comprise one or more elastic strings or elements 233 in the region of the leg opening between the topsheet 224 and the backsheet 225 in the chassis of the absorbent article. All or a portion of the barrier leg cuffs and / or gasket cuffs may be treated with a lotion or another skin care composition.
[0140] Capture and distribution system The absorbent articles of the present disclosure may comprise an acquisition-distribution layer or system 250 ("ADS"). One function of the ADS is to rapidly acquire one or more of the fluids and distribute them efficiently to the absorbent core. The ADS may comprise one, two, or more layers, which may form an integral layer or may remain as separate layers that may be attached to one another. In one example, the ADS may comprise two layers, a distribution layer 254 and an acquisition layer 252, disposed between the absorbent core and the topsheet, although the present disclosure is not so limited.
[0141] In one example, the high loft three-dimensional nonwoven material of the present disclosure may include a topsheet and an acquisition layer as a laminate. A distribution layer may also be provided on the garment-facing side of the topsheet / acquisition layer laminate.
[0142] Carrier Layer In cases where the high loft three-dimensional nonwoven material of the present disclosure includes a topsheet and acquisition layer laminate, the distribution layer may need to be supported by a carrier layer (not shown), which may include one or more nonwoven materials or other materials. The distribution layer may be applied to or positioned on the carrier layer. As such, the carrier layer may be positioned intermediate the acquisition layer and the distribution layer and may be in a facing relationship with the acquisition layer and the distribution layer.
[0143] distribution layer The distribution layer of the ADS may comprise at least 50% by weight of crosslinked cellulose fibers. The crosslinked cellulose fibers may be crimped, twisted, or curled, or a combination thereof including crimped, twisted, and curled. Materials of this type are disclosed in US Patent Application Publication No. 2008 / 0312622(A1) (Hundorf). The crosslinked cellulose fibers provide the first absorbent layer with high resilience and therefore high resistance to compression under product packaging conditions or use conditions (e.g., under the weight of the wearer). This may provide the core with higher void volume, permeability, and liquid absorbency, thereby reducing leakage and improving dryness.
[0144] A distribution layer comprising the crosslinked cellulose fibers of the present disclosure may comprise other fibers, but advantageously the layer may comprise at least 50%, or 60%, or 70%, or 80%, or 90%, or even up to 100% crosslinked cellulose fibers (including the crosslinking agent) by weight of the layer.
[0145] capture layer In cases where the three-dimensional nonwoven material of the present disclosure is provided solely as a topsheet for an absorbent article, the ADS 250 may include an acquisition layer 252. The acquisition layer may be disposed between the distribution layer 254 and the topsheet 224. In such cases, the acquisition layer 252 may be or include a nonwoven material, such as a hydrophilic SMS or SMMS material, including spunbond, meltblown, and even spunbonded layers, or alternatively, chemically bonded nonwovens of carded staple fibers. The nonwoven material may be latex bonded.
[0146] Fastening System The absorbent article may include a fastening system. The fastening system may be used to provide lateral tension around the circumference of the absorbent article to hold the absorbent article against the wearer, as is typical for taped diapers. This fastening system may not be required for training pant articles, since the waist region of these articles is already joined. The fastening system may include fasteners, such as, for example, tape tabs, hook and loop fastening elements, mating fasteners such as tabs and slots, buckles, buttons, snaps, and / or hermaphroditic fastening elements, although any other suitable fastening mechanisms are within the scope of this disclosure. Typically, a landing area 244 is provided on the garment-facing surface of the front waist region 205 to allow for releasable attachment of fasteners.
[0147] Front and back ears The absorbent article may comprise front ears 246 and back ears 240. The ears may be integral parts of the chassis, such as formed as side panels from the topsheet 224 and / or backsheet 226. Alternatively, as shown in FIG. 28, the ears may be separate elements attached by gluing, heat embossing, and / or pressure bonding. The back ears 240 may be stretchable to facilitate attachment of the tabs 242 to the landing areas 244 and to keep the taped diaper in place around the waist of the wearer. The back ears 240 may also be elastic or stretchable to provide a more comfortable, form-fitting fit by initially fitting the absorbent article snugly to the wearer and then maintaining this fit throughout the entire wear period, even long after the absorbent article has been filled with fluids or other body exudates, because the elastic ears allow the sides of the absorbent article to stretch.
[0148] Elastic waist mechanism The absorbent article 220 may also include at least one elastic waist feature (not shown) that helps provide improved fit and containment. The elastic waist feature is generally intended to elastically expand and contract to dynamically fit the waist of the wearer. The elastic waist feature may extend at least longitudinally outward from at least one waist edge of the absorbent core 228 to generally form at least a portion of the edge of the absorbent article. A disposable diaper may be constructed with two elastic waist features, one located in the front waist region and the other located in the back waist region.
[0149] Color Signals In one form, the absorbent article of the present disclosure can have different colors in different layers or portions thereof (e.g., the topsheet and acquisition layer, the topsheet and nonwoven core cover, the first and second portions of the topsheet, the first and second portions of the acquisition layer). The different colors can be shades of the same color (e.g., dark blue and light blue) or can actually be different colors (e.g., purple and green). The different colors can have, for example, a ΔE in the range of about 1.5 to about 10, about 2 to about 8, or about 2 to about 6. Other ΔE ranges are also within the scope of the present disclosure.
[0150] In one example, different layers of the absorbent article can be joined together by a colored adhesive. The colored adhesive can be disposed in a pattern on any suitable layer or layers. The adhesive pattern may or may not complement the pattern of the topsheet. Such a pattern can increase the visual depth of the absorbent article. In a particular embodiment, the colored adhesive can be blue in color.
[0151] In other examples, either layer may have indicia, such as printed inks, that aid in the appearance, impression of depth, impression of absorbency, or impression of quality of the absorbent article.
[0152] In other examples, the color may be complementary or aligned with the pattern of three-dimensional features of the nonwoven fabric 10 used as a component of the absorbent article. For example, a fabric having first and second regions of a visually distinct pattern of three-dimensional features may be printed with a color to accentuate, highlight, contrast, or otherwise alter the appearance of the fabric 10. Color accentuation may be effective in communicating to the user of the absorbent article certain functional properties of the nonwoven fabric 10 during use. Thus, the combination of structural three-dimensional features and color in one component or a combination of components can provide a visually striking absorbent article. For example, a secondary topsheet or acquisition layer may be printed with one or more color patterns that complement the pattern of three-dimensional features of the fabric 10 used as the topsheet of the absorbent article. Another example is an absorbent article having 1) an absorbent core having channels, 2) a topsheet having a three-dimensional pattern that aligns with or accentuates one or more channels in the core, and 3) graphics, colored elements, printed inks, or indicia viewable from the topsheet viewing surface (surface that contacts the body) or the backsheet viewing surface (surface that faces the garment) to further accentuate the functional features of the one or more channels in the core and the overall performance of the absorbent article.
[0153] Further characterization of the novel aspects of the present disclosure can be achieved by looking at the three-dimensional features within the visually distinct regions. Each of the regions, such as regions 110, 120, and 130 described above, can be further described in relation to a microregion. A microregion is a portion of the nonwoven fabric 10 within a region that has at least two visually distinct regions, and a common intensive property difference exists between the two regions. A microregion can comprise a portion of the nonwoven fabric 10 that crosses the boundary of two or more regions, and has at least two visually distinct regions, and a common intensive property difference exists between the two regions.
[0154] The advantage of considering microzones in the present disclosure is to illustrate that, apart from the difference in average intensive properties by zones such as zones 110, 120, and 130 as described above, the present disclosure also provides fabrics having actual and / or average intensive property differences between the regions defined by the three-dimensional features within the zones, where the three-dimensional features are precisely positioned according to the design of the forming belt used to produce the fabric. The difference in intensive properties between the regions of the three-dimensional features provides not only functional benefits, but also additional visual effects. The clear visual contrast between the regions can provide very good visually clear designs within a zone and between zones. Similarly, the precise positioning of the regions provided by a precisely manufactured forming belt can provide excellent and tailored softness, strength, and liquid handling properties for each zone. Thus, the present invention, in one embodiment, provides an unexpected combination of the difference in average intensive properties between the zones and at the same time the difference in intensive properties of the regions that make up the microzones.
[0155] The regions defined by the three-dimensional features can be understood with reference to Figures 38 and 39. Figure 38 shows an optical microscope image of a portion of a fabric 10 according to the present disclosure, and Figure 39 shows a scanning electron micrograph (SEM) of a cross-section of the portion of the fabric shown in Figure 38. That is, Figures 38 and 39 show a portion of nonwoven fabric 10 enlarged for a more accurate depiction of the fabric's otherwise visually distinct features. The portion of nonwoven fabric 10 shown in Figure 38 is approximately 36 mm in the CD and shows portions of at least three visually distinct regions as described below.
[0156] In Figs. 38 and 39, which show a portion of one pattern of the nonwoven fabric 10, the first region 110 (left side of Fig. 38) is characterized by generally MD rows of first regions 300 of varying width separated by MD rows of second regions 310 of varying width. The first regions are also three-dimensional features 20 that define the first and second regions 300, 310. In one embodiment, the three-dimensional features are portions of the nonwoven fabric 10 formed between or around raised elements of the forming belt, which in this description are the first regions 300, and the resulting structure has a relatively large dimension in the Z direction. The adjacent second regions 310 generally have intensive properties in common with the first regions 300, and in one embodiment have a relatively small value of thickness (i.e., a smaller dimension in the Z direction). The relative dimensions in the Z direction with respect to the plane of the first surface 16 discussed above can be seen in Fig. 39. The absolute dimensions are not critical, but the dimensional difference may be visually distinguishable on the nonwoven fabric 10 without magnification.
[0157] The disclosed invention allows useful features to be best expressed relative to the regions defined by the three-dimensional features within the microregion. For example, as shown in FIG. 38, within the region 110 within each three-dimensional feature 20, there is a visual distinction between the first region 300 and the second region 310. As noted above, the visual distinction can be present within the nonwoven fabric 10 without magnification, and the magnification used herein is for purposes of clarity of disclosure. Any region that extends sufficiently across the boundary between the first region 300 and the second region 310 such that a difference in the respective intensive properties can be considered within that region can be a microregion. Additionally, optical microscopy or micro-CT images of a structure can be used to establish the location of each region and the area of the microregion.
[0158] The portion of nonwoven fabric 10 shown in Figure 38 further illustrates another useful feature of fabric 10 in that the difference in intensive properties between adjacent regions can be a difference across each region. Thus, micro-regions can be identified across the region including second region 310 of region 120 and first region 300 of region 130. Certain embodiments including nonwoven fabric 10 shown in Figures 38 and 39 illustrate that the difference in intensive properties exhibited by regions within a micro-region can be significantly different in magnitude than the difference in intensive properties exhibited by regions within a region at the region boundary.
[0159] Regardless of which zones or zone boundaries a particular microzone includes, the three-dimensional features can be characterized by the difference in intensive properties of each region defined by the three-dimensional features. In general, the nonwoven fabric of the present disclosure can be a spunbonded nonwoven fabric having a first surface that defines a plane of the first surface. The fabric can have a plurality of three-dimensional features that each define a first region and a second region, each region having a common intensive property with a different value between them. In one embodiment, the first region is at a higher height relative to the plane of the first surface than the second region, and thus can be distinguished as showing a difference in the common thickness intensive property of each region. The two regions can also be distinguished as having different densities, basis weights, and volume densities. That is, the two regions can be distinguished as different with respect to the common intensive property, including properties such as thickness, density, basis weight, and volume density, within the microzone of the spunbonded nonwoven fabric. In one embodiment, one or both regions of the microzone can be fluid permeable. In one embodiment, the denser regions of the microzone may be fluid permeable.
[0160] For example, within region 110 of the fabric portion shown in Figure 38, there may be a three-dimensional feature 20 that defines at least two regions, a first region 300 and a second region 310. The differences in caliper, basis weight, and volume density between the first region and the second region of region 110 shown in Figure 38 may be 274 μm, 1 gsm, and 0.437 g / cc, respectively.
[0161] Similarly, within the region 130 of the portion of the fabric shown in, for example, FIG. 38, there may be a three-dimensional feature 20 that defines at least two regions, a first region 300 and a second region 310. The differences in caliper, basis weight, and volume density between the first region and the second region of the region 130 shown in FIG. 38 may be 2083 μm, 116 gsm, and 0.462 g / cc, respectively.
[0162] Additionally, for example, within region 120 of the fabric portion shown in Figure 38, there may be three-dimensional features 20 that define at least two regions, a first region 300 and a second region 310. The difference in thickness, basis weight, and volume density between the first region and the second region of the fabric portion shown in Figure 38 may be 204 μm, 20 gsm, and 0.53 g / cc, respectively. In the embodiment shown, region 120 forms what is visible in a non-magnified view of nonwoven fabric 10 as a sewn boundary between regions 110 and 130.
[0163] Further, for example, in the area including the boundary between areas 120 and 130 of the fabric portion shown in Figure 38, there are at least two areas: a first area 300 in area 130 and a second area 310 in area 120. The differences in caliper, basis weight, and volume density between the first area and the second area of the fabric portion shown in Figure 38 can be 2027 μm, 58 gsm, and 0.525 g / cc, respectively.
[0164] The microzones will be described in more detail with reference to the data shown in Figures 40-42 and 44. Figures 40-42 are micro-CT scans of a portion of nonwoven fabric 10 having a similar pattern to the portion of nonwoven fabric 10 shown in Figure 38. The micro-CT scan allows for the same features shown in Figure 38 to be described in a slightly different manner, and in a manner that allows for very accurate measurement of intensive properties.
[0165] As shown in Figure 40, areas 110, 120, and 130 are clearly visible along with their respective three-dimensional features 20. As shown in Figures 40 and 41, the three-dimensional features are the dark portions, and the dark portions also represent a first region 300 of the three-dimensional features 20, and the adjacent light portions are a second region 310 of the three-dimensional features 20.
[0166] Micro-CT scanning allows the image to be shown as a "cut" cross-section as shown by cut plane 450 in Figure 41. The cut plane can be located anywhere in the image, but for purposes of this disclosure, cut plane 450 is a cut substantially parallel to the Z axis to obtain the cross-sectional image of Figure 42.
[0167] Micro-CT techniques allow for accurate and direct measurement of intensive properties. Thickness measurements can be made directly from cross sections imaged under magnification, such as the cross section shown in FIG. 42. Furthermore, the difference in color between the first and second regions represents, and is proportional to, differences in basis weight, volume density, and other intensive properties, which can also be directly measured. The micro-CT method is described in the Test Methods section below.
[0168] Figure 43 is a micro-CT scan image of the portion of nonwoven fabric 10 shown in Figures 40 and 41. Analysis can be performed using specific first and second regions, shown as numbered portions of nonwoven fabric 10. In Figure 43, specific regions were manually selected and analysis was performed to measure caliper, basis weight and volume density, and the data is shown in Figure 44.
[0169] FIG. 44 shows data groupings of first and second region measurements made within the three regions shown in FIG. 44. The x-axis is each region and the numbers correspond to the numbered regions in FIG. 43. The measurements of the first region are shown as Fn (e.g., F1) and the measurements of the second region are shown as Sn (e.g., S1). Thus, regions 1-5 are the first region F1, each within region 110. Regions 6-10 are the second region S1, also within region 110. Similarly, the first region F2 is regions 16-20 within region 120, and regions 11-15 and 21-25 are the second region S2 within region 120. Finally, regions 31-35 are the first region F3 within region 130, and regions 26-30 are the second region S2 within region 130. Each numbered region is shown identically in all three graphs of FIG. 44, although for simplicity, areas 110, 120, and 130 are shown only in the thickness map.
[0170] Each graph shown in FIG. 44 is a graphical representation of the magnitude of the difference in intensive properties between a first region and a second region within any one region, and these graphs can be used to graphically view the difference in intensive properties for each pair of regions that make up the microregion. For example, in region 110, the basis weight may be substantially the same between the two regions, but the thickness (caliper) may vary from about 400 μm in the first region to about 40 μm in the second region (i.e., about a 10X difference). The volume density within region 110 may vary from about 0.1 g / cc to about 0.6 g / cc. Similar quantifiable differences can be seen for each of the regions shown in the figure.
[0171] Thus, by jointly referring to Figures 43 and 44, further characterization of the useful structure of the fabric 10 of the present disclosure can be appreciated. The nonwoven fabric 10 can be described as having at least two visually distinct regions, e.g., regions 110 and 120, each of which has a pattern of three-dimensional features, each of which defines a microregion including a first and a second region, e.g., regions 300, 310, where the difference in value in at least one of the microregions in the first region is quantifiably different from the difference in value in at least one of the microregions in the second region. For example, in Figure 43, two representative microregions 400 in region 130 are designated as pairs of regions shown as regions 31 and 27, and regions 33 and 26. That is, the first region 31 and the second region 27 form one microregion, and the first region 33 and the second region 26 form one microregion. Similarly, two representative microregions 400 within region 120 are designated as pairs of regions shown as regions 19 and 24, and regions 17 and 22. From Figure 44, Tables 4-7 can be derived as shown below.
[0172] [Table 4]
[0173] [Table 5]
[0174] [Table 6]
[0175] [Table 7]
[0176] Four representative microzones from the two regions are shown in Tables 4-6 for illustrative purposes. However, as will be appreciated, each pair of first and second regions in FIG. 43 could also be quantified to further constitute additional columns in Table 4, but for the sake of brevity, this has not been done. In general, in any fabric having two or more regions, each having a pattern of three-dimensional features defining a microzone, the intensive properties can be measured and tabulated as shown herein with reference to FIG. 43 and FIG. 44 to understand both the difference in the value of the intensive property within a region and the difference in the value of the intensive property between one region in the first region and another region in the second region.
[0177] A micro-zone across two zones, such as zone 110 and zone 130, may have even greater intensive property differences relative to a micro-zone within a zone. For example, looking at data for a micro-zone across a first zone (e.g., first zone 32) in zone 130 and a second zone (e.g., second zone 8) in zone 110, the micro-zones show significant differences in thickness, basis weight, and volume density. The thickness of the first zone 32 in zone 130 is about 2100 μm, while the thickness of the second zone 8 in zone 110 is about 29 μm (i.e., a difference of about 72×). Similarly, the basis weight of the first zone 32 in zone 130 may be as high as 150 gsm, while the basis weight of the second zone 8 in zone 110 may be about 14 gsm (i.e., a difference of about 10×). Additionally, the volume density of the first region 32 of the area 130 may be approximately 0.069 g / cc, while the volume density of the second region 8 of the area 110 may be 0.492 g / cc (ie, a difference of approximately 7X).
[0178] For each of the measured intensive property parameters of different regions of a micro-zone, such measurements are made using the micro-CT method described herein. The resolution of the method supports establishing the intensive properties of each region of the micro-zone, so that comparisons of differences and ratios of each region can be made as described herein.
[0179] Further characterization of the fabric 10 can be performed with reference to Figures 45-49, which are SEMs showing more detailed particular aspects of the nonwoven fabric 10 and regions thereof. Figures 45-49 are photographs of enlarged portions of area 110 of the fabric shown in Figure 38. The nonwoven fabric 10 shown in Figure 38 was made according to the process described above with reference to Figure 7, where the fabric was processed by passing it through a nip formed by compression rolls 70 and 72, with roll 72 in contact with first surface 12 being heated to cause partial bonding of the fibers in second region 301. Figure 45 (facing the belt) and Figure 46 (facing the heated compression roll) are SEMs of portions of second surface 14 and first surface 12, respectively, magnified 20 times. FIG. 47 (facing the belt) and FIG. 48 (facing the heated compression rolls) are photographic views, magnified 90 times, of a portion of second surface 14 and first surface 12, respectively, detailing the useful structural features of the partial fiber bonding created by compression rolls 70 and 72.
[0180] As best seen in Figures 47 and 48, as well as the cross-sectional view of Figure 49, the heated compression rolls can cause thermal bonding of the fibers to differing degrees, resulting in beneficial effects throughout the fabric 10. As shown in the figures, the fibers in contact with the heated rolls (e.g., roll 70 in contact with the first surface 12 of the fabric 10) can be melt bonded, such that the first surface 12 experiences relatively higher fiber-to-fiber bonding than the second surface 14. In one embodiment, the bonded fibers 80 on the first surface can be substantially completely melt bonded to, in effect, form a film skin of bonded fibers, while the fibers in the second region 310 on the second surface 14 experience little or no bonding. This feature allows the nonwoven fabric 10 used as, for example, a topsheet in a disposable absorbent article to maintain physical integrity during manufacture and use, as well as relatively high flexibility on one side, which may be the skin-contacting side facing the user.
[0181] Even in the small areas with the greatest thickness differences, this "glue-skin" effect serves to maintain the integrity of the web without significantly affecting other useful properties such as softness or liquid handling properties. As can be seen by reference to Figures 50-53, the difference in the degree of thermal bonding of the fibers is such that the fibers on first surface 12 in second region 310 may be complete, or substantially complete, while the fibers on second surface 14 in first region 300 are minimally thermally bonded, or not thermally bonded at all.
[0182] FIG. 50 also shows a portion of the nonwoven fabric 10 shown in FIG. 38. FIGS. 51-53 show magnified images of one microzone, shown in FIG. 50 as first region 300 and second region 310, which visually appear as holes or openings. FIGS. 51 and 52 show the microzones as seen on the second surface 14 magnified at 40× and 200×, respectively. FIG. 53 shows the second region 310 as seen on the first face 12 at 200× magnification. The fibers in the second region 310 are completely or substantially completely bonded, while the fibers in the first region 300 are completely or substantially completely unbonded. An advantage of the structure shown in the figures is that the microzones can function as fluid permeable openings while at the same time the bonded areas of the second region 310 function to maintain the physical integrity of the fabric 10.
[0183] Thus, microregions play an important role in the overall physical structure and function of the fabric 10 of the present invention. By producing the relatively closely spaced, precisely engineered three-dimensional features achieved by the forming belt of the present disclosure, the fabric 10 can exhibit visually distinct regions, microregions, and three-dimensional features that impart superior functionality, at least in the areas of softness and liquid handling, as well as a visually appealing aesthetic design. The potential differences in the physical properties of the first and second surfaces allow for the design of the nonwoven fabric 10 in terms of both strength and softness, both form and function.
[0184] FIG. 54 is a micro-CT scan image of a portion of nonwoven fabric 10 similar to that shown in FIGS. 40 and 41, but which has been subjected to further processing steps to form point bonds 90 within the nip of calendar rollers 71 and 73. As above, with respect to the discussion of FIGS. 43 and 44, the first and second regions shown as numbered portions of nonwoven fabric 10 can be analyzed for specific point bond microzones 400, which may include areas of point bonds in particular numbered regions 31-35. For example, adjacent regions 32 and 26 form a microzone 400 within third region 130. In FIG. 54, certain regions have been visually differentiated to identify areas containing added point bond areas, which were analyzed to measure thickness, basis weight, and volume density, and the data is presented in FIG. 55, where the thickness, basis weight, and volume density of all areas containing point bond areas are quantified and compared.
[0185] FIG. 55 shows data groupings of first and second region measurements made within the three regions shown in FIG. 54. The x-axis is each region and the numbers correspond to the numbered regions in FIG. 43. The first region measurements are designated as Fn (e.g., F1) and the second region measurements are designated as Sn (e.g., S1). Thus, regions 1-5 are first region F1, each within region 110. Regions 6-10 are second region S1, also within region 110. Similarly, first region F2 is regions 16-20 within region 120, and regions 11-15 and 21-25 are second region S2 within region 120. Finally, regions 31-35 are second regions, but are point bonds 90, designated as B1 in FIG. 55, and are distinguished in this disclosure as being formed by a point bonding process. A first region F3 within region 130 is regions 26-30 and 36-40, and regions 41-44 are a second region S2 within region 130. Each numbered region is shown identically in all three graphs of FIG. 55, however, for simplicity, regions 110, 120, and 130 are shown only in the thickness map.
[0186] Each graph shown in FIG. 54 graphically represents the magnitude of the difference in intensive properties between a first region and a second region within any one region of a fabric subjected to a calendering point bonding process, and these graphs can be used to graphically view the difference in intensive properties for each pair of regions that make up the microregion. For example, in region 110, it can be seen that the basis weight between the two regions can vary within a narrower range than the thickness or volume density. For example, the thickness (caliper) can vary from about 325 μm in the first region of region 110 to about 29 μm in the second region (i.e., a difference of about 10X). The volume density within region 110 can vary from about 0.08 g / cc to about 0.39 g / cc. Similar quantifiable differences can be seen for each of the regions shown in the figure.
[0187] In general, each region of a microregion may have widely varying values for basis weight, thickness, and volume density.
[0188] Thus, by referring jointly to Figures 54 and 55, further characterization of the useful structures of the fabric 10 of the present disclosure can be appreciated, particularly with respect to the thermal calendar point bonds 90. Focusing on region 130 for illustrative purposes, the three-dimensional features that define the microzone, including the first and second regions that are point bonded regions, can be identified and the values of the intensive properties can be quantified. For example, in Figure 54, a representative point bonded microzone 400 within region 130 can be a pair of regions shown as regions 26 and 32, or regions 30 and 35. That is, first region 26 and second region 32 form one point bonded microzone 400, and first region 30 and second region 35 form one point bonded microzone 400.
[0189] The difference in certain intensive properties of the point bonded microzones can be seen in Figure 55. For example, taking the two point bonded microzones 400 discussed above (e.g., the two point bonded microzones 400 in regions 26 and 32 and regions 30 and 35, respectively), it can be seen that while there is a small difference in basis weight between the first and second regions, ranging from about 55 to about 60 gsm, the same regions exhibit a large difference in thickness from about 430 μm to about 460 μm to about 125 μm, and a large difference in bulk density from about 0.13-0.14 g / cc to about 0.41-0.48 g / cc. Other differences in intensive properties can be seen with reference to Figure 55.
[0190] Point bonds 90 can play an important role in the overall physical structure and function of the inventive fabric 10. By adding point bonds 90 to a fabric 10 containing relatively closely spaced, precisely designed three-dimensional features, as achieved by the forming belt of the present disclosure, the fabric 10 can be further improved to exhibit unexpected combinations of visually distinct zones, micro-zones, and three-dimensional features that not only provide superior functionality in the high performance combination of softness, strength, low fuzz, and liquid handling, but also provide a visually appealing aesthetic design. Point bond features allow the nonwoven fabric 10 to be designed for the highest performance combination of strength, softness, liquid handling, and visual aesthetics, especially when form and function are considered.
[0191] One advantage of the formed nonwoven webs of the present disclosure is improved softness. Softness can be measured using an Emtec Tissue Softness Analyzer, available from Emtec Paper Testing Technology, Emtec Electronic, GmbH. Table 5 below shows the softness values as TS7 measurements from the Emtec Tissue Softness Analyzer according to the Emtec test method below. In all of the following Examples 7-9, the nonwovens were made on the belt described in FIG. 16, and the nonwoven webs had an appearance similar to that shown in FIG. 2.
[0192] [Table 8]
[0193] Example 7: A bicomponent spunbond nonwoven fabric was produced by spinning a 50:50 ratio of a polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) into a trilobal fiber configuration as described above with respect to Example 2. The nonwoven fabric was spun onto a forming belt having a repeating pattern as described in FIG. 16 moving at a linear speed of about 25 m / min to produce an average basis weight of 25 g / m2 with a diamond repeating pattern as shown in FIG. 2 The fibers of the fabric were compressed by compression rolls 70, 72, but rather than being calendered, further bonding was achieved at a temperature of 145° C. in a through-air bonding unit as described below with respect to FIG.
[0194] (Example 8): A bicomponent spunbond nonwoven fabric was produced by spinning a polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (HG475FP obtained from Borealis) in a ratio of 30:70 into the form of round fibers using a dual beam spunbond process as described in Figure 56. The nonwoven fabric was spun as described above with respect to Figure 7 onto a forming belt having a repeating pattern as described in Figure 16 moving at a linear speed of about 152 m / min with an average basis weight of 35 g / m. 22 to form a repeating diamond pattern as shown in FIG. 2. The difference between the molded nonwoven web produced according to the process of FIG. 7 and Example 8 is that Example 8 was produced by a combination of the process described in FIG. 7 and the process described in FIG. 56 below. Specifically, the process uses two spin beams as shown in FIG. 56, but the final heating step is performed by calendar rolls 71, 73 rather than through-air bonding. The fibers of the fabric are bonded on the first surface 12 by compression rolls 70A and 72A heated to 110° C. after the first beam 48A, further bonded by compression rolls 70B and 72B at 110° C. after the second beam 48B, further calender bonded by calendar rolls 71 and 73 at about 140° C. before being wound on a reel in a winder 75.
[0195] (Example 9): A bicomponent spunbond nonwoven fabric was produced by spinning a polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (HG475FP obtained from Borealis) in a ratio of 30:70 into the form of round fibers using a dual beam spunbond process as described in Figure 56. The nonwoven fabric was spun at an average basis weight of 25 g / m2 onto a forming belt having a repeating pattern as described in Figure 16 moving at a linear speed of about 228 m / min. 2 2, forming a repeating diamond pattern as shown in Figure 2. The fibers of the fabric were further bonded onto the first surface 12 by compression rolls 70A and 72A heated to 110°C after the first beam 48A, further bonded by compression rolls 70B and 72B at 110°C after the second beam 48B, further hot through-air bonded in three heating zones at 100°C, 135°C, and 135°C of a through-air bonder 76 (shown in Figure 56), and then wound onto a reel in a winder 75.
[0196] Examples 7-9 are representative of molded nonwoven fabrics of the present disclosure that exhibit high softness as shown by Emtec measurements. The Emtec measurements are approximately 1 dBV 2rms to approx. 15 dBV2 rms, or approx. 3 dBV 2 rms ~ approx. 10 dBV 2 rms, or about 5 dBV 2 rms ~ approx. 8 dBV 2 Typically, the Emtec measurements for either the first or second surface are approximately 15 dBV 2 It can be any integer value less than or equal to rms, and can range from any integer between 1 and 15. Furthermore, in general, the ratio of the Emtec measurements of the first surface to the second surface can be between 1 and 3, and can be any real number between 1 and 3.
[0197] Without being bound by theory, it is believed that the improved softness exhibited by the shaped nonwoven fabric of the present invention is achieved by the method and apparatus of the present invention, which allows different intensive properties in relatively small areas, including the disclosed areas and microareas. The ability to design and manufacture nonwoven fabrics with the disclosed differences in basis weight, density, or thickness while simultaneously providing a consolidated fabric useful for the topsheet of an absorbent article, for example, eliminates the technical conflict between surface texture and softness, which has been a problem in the past. That is, the shaped nonwoven fabric of the present disclosure can provide excellent softness as indicated by Emtec measurements, along with visually noticeable surface textures, including irregular patterns. Furthermore, the shaped nonwoven fabric of the present disclosure can provide a combination of visually noticeable surface textures, physical integrity, and low fuzz properties, along with excellent softness as indicated by Emtec measurements.
[0198] As mentioned above, in one example, the process for producing a molded nonwoven fabric can be a modification of the process described with respect to Figure 7. One such modification is described with respect to Figure 56. As shown in Figure 56, the process can include a belt 60 as described above in a melt spinning process using two or more spin beams. As shown diagrammatically with only spin packs 48A and 48B, two beams can be used to melt spin the fibers onto the belt 60, each followed by a compression operation 70A, 72A and 70B, 72B, respectively. Vacuum boxes 64A and 64B can be operatively associated with each spin beam 48A and 48B, respectively.
[0199] After the fibers are spun onto belt 60 and compressed, with optional thermal bonding during compression as described above, the formed nonwoven web can be further heated by ventilated heater 76, which can have multiple chambers, such as three chambers 76A, 76B and 76C, each of which is independently temperature controlled.
[0200] Examples 7 and 9 above were made on a dual beam process line and through-air bonded in the process shown generally in Figure 56. Without being bound by theory, it is believed that through-air bonding preserves much of the three-dimensional character of the three-dimensional features of the molded nonwoven, as shown by the difference in TS7 values in Table 5. Alternatively, if a nonwoven with fewer surface features is desired, it is believed that calendar bonding tends to make the TS7 values more uniform, as shown in Example 8 in Table 5. Thus, by controlling the parameters of this process as described herein, a desired softness can be achieved on each side (i.e., surface) of the molded nonwoven.
[0201] In addition to the benefits detailed above, another advantage of the shaped nonwoven web of the present disclosure is the ability to provide the nonwoven web with microzones having hydrophobic regions and distinct hydrophilic regions. The hydrophilicity and / or hydrophobicity of a particular region of a microzone can be determined by wicking time measurements using the wicking time test method described herein and / or contact angle measurements using the contact angle test method described herein. When used herein with respect to a particular region of a microzone, the term "hydrophilic" means that the wicking time of the particular region is less than 10 seconds when tested using the wicking time test method. When used herein with respect to a particular region of a microzone, the term "hydrophobic" means that the contact angle of the particular region is 90° or more when tested using the contact angle test method.
[0202] Table 6 below details the contact angle and wick time measurements for the molded nonwovens detailed herein. In both Examples 10 and 11 below, the nonwovens were made on the belt illustrated in Figure 16, and the nonwoven web had an appearance similar to that shown in Figure 2.
[0203] [Table 9]
[0204] (Example 10): A bicomponent spunbond nonwoven fabric was produced by spinning a 50:50 ratio of a polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) into a trilobal fiber configuration as described above with respect to Example 2. The nonwoven fabric was spun onto a forming belt having a repeating pattern as described in FIG. 16 moving at a linear speed of about 25 m / min to produce an average basis weight of 25 g / m2 with a diamond repeating pattern as shown in FIG. 2The fibers of the fabric were compressed by compression rolls 70, 72, but rather than being calendered, further bonding was achieved at a temperature of 145° C. in a through-air bonding unit as described below with respect to FIG.
[0205] A surfactant, Stantex S 6327 (a combination of castor oil ethoxylate and PEG diester) supplied by Pulcra Chemicals, was then placed on the backside of the nonwoven (i.e., the flat surface opposite to the side on which the relatively pillow-like three-dimensional features were placed) through a kiss coating process. The coating process was carried out using a Reicofil Kiss Roll and Omega drying process, both of which are commonly known in the art. The surfactant used in the kiss roll process was a 6% surfactant concentration in water at a temperature of 40°C. The kiss roll contact angle was set at 250° and the drying temperature was 80°C. The nonwoven was then contacted with a kiss roll operating at a speed of 13 rpm, providing 0.45 wt% surfactant to the nonwoven (surfactant % is 1 m 2 The weight of surfactant added per 1 m 2 (The weight of the nonwoven fabric is calculated by dividing the weight by the weight of the nonwoven fabric.)
[0206] (Example 11): A bicomponent spunbond nonwoven fabric was produced by spinning a 50:50 ratio of a polyethylene sheath (Aspun-6850-A obtained from Dow chemical company) and a polypropylene core (PH-835 obtained from LyondellBasell) into a trilobal fiber configuration as described above with respect to Example 2. The nonwoven fabric was spun onto a forming belt having a repeating pattern as described in FIG. 16 moving at a linear speed of about 25 m / min to produce an average basis weight of 25 g / m2 with a diamond repeating pattern as shown in FIG. 2 The fibers of the fabric were compressed by compression rolls 70, 72, but rather than being calendered, further bonding was achieved at a temperature of 145° C. in a through-air bonding unit as described below with respect to FIG.
[0207] A surfactant, Stantex S 6327 (a combination of castor oil ethoxylate and PEG diester) supplied by Pulcra Chemicals, was then placed on the front side of the nonwoven (i.e., the side with the relatively pillow-like three-dimensional features located on top) through an inkjet printing process. The inkjet printing process was performed using a Dimatix DMP 2831 inkjet printer equipped with cartridge model # DMC-11610 / PM 700-10702-01 (10 pL). The print head temperature was 40° C. The surfactant used in the inkjet printing process consisted of 75 wt / wt% Stantex S 6327 and 25 wt / wt% ethanol. The surfactant was printed in the second area of the microzone of the nonwoven by orienting the nonwoven sample such that the second area of the microzone of the first row was aligned with the print head direction and printing a first series of straight lines with the droplet spacing adjusted to 170 μm. The nonwoven sample was then rotated by an angle such that the second region of the second row of microzones was aligned with the print head and a second series of straight lines was printed at 170 μm. The basis weight of the fibers in the second region was about 16.0 gsm. The basis weight of the surfactant inkjet printed on the second region was about 0.25 gsm. Thus, the amount of surfactant locally printed on the second region was determined to be about 1.6 wt. % surfactant (0.25 gsm / 16.0 gsm). Overall, the amount of surfactant printed on the nonwoven sample was determined to be about 0.2 wt. % surfactant by the ratio of the printed line width to the line spacing.
[0208] In addition to Stantex S 6327, the use of other surfactants (by any method of application) to render the first and / or second regions of a particular microzone hydrophilic and / or hydrophobic are considered within the scope of this disclosure. Other potential surfactants for use in the processes and nonwovens detailed herein include nonionic surfactants including esters, amides, carboxylic acids, alcohols, ether-polyoxyethylenes, polyoxypropylenes, sorbitans, ethoxylated fatty alcohols, allylphenol polyethoxylates, lecithins, glycerol esters and their ethoxylates, and sugar-based surfactants (polysorbates, polyglycosides), as well as sulfonates, sulfates, phosphates, alkali metal salts of fatty acids, fatty alcohol monoesters of sulfuric acid, linear alkylbenzene sulfonates, alkyl diphenyl oxide sulfonates, lignin sulfonates, olefin sulfonates, sulfosuccinates, and sulfated ethoxylates of fatty alcohols. anionic surfactants including xylates; cationic surfactants including amines (primary, secondary, tertiary), quaternary ammonium, pyridinium, quaternary ammonium salts-quats, alkylated pyridinium salts, alkyl primary, secondary, tertiary amines, and alkanolamides; zwitterionic surfactants including amino acids and derivatives, amine oxides, betaines, and alkylamine oxides; polymeric surfactants including polyamines, carboxylic acid polymers and copolymers, EO / PO block copolymers, ethylene oxide polymers and copolymers, and polyvinylpyrrolidone; and hydrophilic dimethylsiloxane polymers and silicone surfactants including perfluorocarboxylates and fluorosurfactants.
[0209] The molded nonwovens detailed above have microzones with regions with differences in intensive properties, such as, for example, basis weight, density, or thickness. Those same molded nonwovens can also have such regions of microzones that are hydrophobic and / or hydrophilic, in particular and separately, at the same time. Any of the examples of molded nonwovens detailed herein (e.g., samples that include regions and / or microzones with regions with differences in thickness, basis weight, and / or volume density, and / or surfaces with various TS7 values disclosed herein) can further have regions of microzones with differences in hydrophilicity, as detailed herein. The hydrophilicity can be provided by targeted application(s) of surfactant(s) onto specific regions of the microzones of the molded nonwoven. For example, a second region of a microzone can have a surfactant disposed thereon, while a first region of the same microzone may not have a surfactant disposed thereon. Additionally, a first region of a microzone can have a surfactant disposed thereon, while a second region of the same microzone may not have a surfactant disposed thereon. For example, in one microzone, the first or second region may have any concentric range of surfactant within the ranges of about 0.01% to about 5.0%, about 0.05% to about 4.0%, about 1.0% to about 3.0%, and about 0.01% to about 5.0%, and the other region has no surfactant (i.e., does not contain surfactant). As an example, in one microzone, the second region may have any concentric range of surfactant within the ranges of about 0.01% to about 5.0%, about 0.05% to about 4.0%, about 1.0% to about 3.0%, and about 0.01% to about 5.0%, and the first region has no surfactant (i.e., does not contain surfactant). Thus, some shaped nonwoven fabrics disclosed herein have microzones having at least one of the first and second regions having surfactant, and the ratio of the surfactant % in the first region to the surfactant % in the second region is less than 1. Additionally, some of the shaped nonwoven fabrics disclosed herein have microzones that include at least a second region of the microzone having a surfactant, where the ratio of the % surfactant in the first region to the % surfactant in the second region is less than 1.
[0210] As another example, a second region of a microzone may have a particular amount or percentage of surfactant disposed thereon, and a first region of the same microzone may have a different amount or percentage of surfactant disposed thereon. For example, in one microzone, the first region may have any concentric range of surfactant within the ranges of about 0.01% to about 2.0%, about 0.05% to about 1.5%, about 0.1% to about 1.0%, and about 0.01% to about 2.0%, and the second region may have a different amount. Furthermore, in one microzone, the second region may have any concentric range of surfactant within the ranges of about 0.01% to about 5.0%, about 0.05% to about 4.0%, about 1.0% to about 3.0%, and about 0.01% to about 5.0%, and the first region may have a different amount. The surfactant % of a particular area of a microzone can be determined by taking the grams per square meter of surfactant placed in the particular area and dividing it by the basis weight of the fibers of the molded nonwoven contained within the same area. The grams per square meter of surfactant placed in the particular area can be determined using any method currently known in the art (e.g., gravimetric measurements, etc.). The basis weight of the fibers of the molded nonwoven contained within the particular area of a microzone can also be determined using any method currently known in the art (e.g., gravimetric measurements, microCT, etc.). The basis weight ranges / examples of the fibers contained in the first and second areas for the examples of particular microzones are detailed above.
[0211] The surfactant may be disposed on the formed nonwoven by any method known in the art. Specific examples include kiss coating, inkjet printing, gravure printing, offset gravure printing, surfactant flexographic printing, and surfactant registration printing. Any such method may dispose the surfactant on either the first and / or second surface of the formed nonwoven. For the entire formed nonwoven (considering all of the individual areas and microareas on the fabric), the surfactant may be added to the formed nonwoven in any concentric range of amounts within the ranges of about 0.01% to about 2.0%, about 0.05% to about 1.5%, about 0.1% to about 1.0%, and about 0.01% to about 2.0%. To calculate the surfactant % added to the entire formed nonwoven, the grams per square meter of surfactant in the entire formed nonwoven is divided by the basis weight of the entire formed nonwoven. The grams per square meter of surfactant disposed in the entire formed nonwoven may be determined using any method currently known in the art (e.g., gravimetric measurements, etc.). The basis weight of the entire molded nonwoven may also be determined using any method currently known in the art (eg, gravimetric methods, micro-CT methods, etc.).
[0212] Referring again to Figures 38 and 39, which show a portion of one pattern of the nonwoven fabric 10, the first region 110 (left side of Figure 38) is characterized by generally MD rows of first regions 300 of varying width separated by MD rows of second regions 310 of varying width (the first and second regions are in a microregion). The first regions are also three-dimensional features 20 that define the first and second regions 300, 310. In one embodiment, the three-dimensional features are portions of the nonwoven fabric 10 formed between or around the raised elements of the forming belt, which in this description are the first regions 300, and the resulting structure has a relatively large dimension in the Z direction, a relatively high basis weight, and a low volumetric density compared to the second regions 310. Additionally, the first regions 300 can be hydrophobic and the second regions 310 can be hydrophilic. The targeted addition of surfactant to the second region 310 of the microzone can render the second region hydrophilic. Thus, the first region 300 of the microzone can have a contact angle greater than about 90°, or between about 90° and about 140°, or between about 110° and about 135°, or between about 125° and about 135°, or any concentric range contained within about 90° and about 140°, when tested by the Contact Angle Test Method detailed herein. The second region 310 of the microzone can have a contact angle less than 90°, when tested by the Contact Angle Test Method detailed herein. The first region 300 of the microzone can have a wick time value greater than about 10 seconds, or between about 10 seconds and 60 seconds, when measured by the Wick Time Test Method detailed herein. The second region 310 of the microzone may have a wick time value of less than about 10 seconds, less than about 5 seconds, or less than about 2.5 seconds, or less than about 1 second, or less than about 0.5 seconds as measured by the Wick Time Test Method detailed herein. The molded nonwoven fabrics contemplated herein include any of the detailed parameter ranges above for the first region and / or second region in combination with any of the contact angle and / or wick time measurements, other intensive properties / property differences disclosed herein, the same or different regions in the same or different microzones on the molded nonwoven fabric.
[0213] For example, shaped nonwovens having the detailed microregions described above having areas of differential basis weight, density, or thickness, while simultaneously also having such areas of specific microregions that are separately hydrophobic and / or hydrophilic, can provide many useful applications, such as topsheet materials for infant care, feminine care, and adult incontinence products, as well as for use in medical pads, wipes, cleaning pads, and the like.
[0214] The dimensions and / or values disclosed herein should not be understood as being strictly limited to the exact numerical dimension and / or value recited. Rather, unless otherwise specified, each such dimension and / or value is intended to mean both the recited dimension and / or value and / or a functionally equivalent range surrounding that dimension and / or value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."
[0215] All documents cited herein, including any cross-references or related patents or applications, are incorporated herein by reference in their entirety unless expressly excluded or otherwise limited. The citation of any document shall not be deemed to be prior art to any invention disclosed or claimed herein, or to teach, suggest, or disclose any such invention, either alone or in combination with any other reference. Furthermore, in the event that any meaning or definition of a term in this document conflicts with a meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
[0216] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
[0217] Test Method: Compression aging test Initial caliper measurement: Cut five 3 inch x 3 inch samples for each nonwoven fabric to be measured. -Number each sample from 1 to 5. -Measure the caliper at 0.5kPa using a Thwing-Albert caliper tester with a standard 65mm foot in the usual way. · Report the initial caliper for each of the five samples. Report the average caliper of five samples. Aging compression method and aging caliper measurement · Stack the five samples, each separated by a paper towel, in an alternating stack starting with sample number 1 and ending with number 5. The stacked samples are placed in an aluminum sample holder with an appropriate weight (4 kPa, 14 kPa, or 35 kPa) on top of the samples. The weighted stack of samples is placed in a 40°C oven for 15 hours. After 15 hours, remove the weights, separate the samples and measure the caliper of each sample at 0.5 kPa using a standard 65 mm foot Thwing-Albert caliper tester in the usual manner. Report the caliper value after aging for each of the five samples. Report the average caliper after aging of five samples. Reporting of analytical results: · Report the average initial and aged calipers by position number. Report the Caliper Recovery Index, i.e. (average aged caliper / average initial caliper) x 100
[0218] Local basis weight The local basis weight of a nonwoven fabric can be measured by several available methods, but a simple representative method is to measure the basis weight of a 3.0 cm 2A die having an area of 0.01 mm is used to cut a sample piece of the web from a selected area of the total area of the nonwoven. The sample piece is then weighed and divided by its area to determine the local basis weight of the nonwoven in g / m2. 2 Results are reported as the average of two samples per selected area.
[0219] Fluffiness test The fuzz test is used to measure the amount of fibers (ie, fuzziness) that are detached from a nonwoven material due to the action of an abrasive force.
[0220] The following materials are used in the fuzz test: · Sutherland Ink Rub Tester equipped with a 2 lb weight, available from Danielee Co, San Antonio, TX. Aluminum Oxide Cloth 320 Abrasive Shop Roll manufactured by Plymouth Coatings, (617) 447-7731. This material can also be ordered from McMaster Carr, part number 468.7A51, (330) 995-5500. 3M #409 double-sided tape, available from Netherland Rubber Company ((513) 733-1085). 3M #3187 Fiber Removal Tape, available from Netherland Rubber Company, (513) 733-1085. Analytical balance (+ / -0.0001g) Paper cutter 2200g weight (metal) 170mm x 63mm. Heavy duty release liner cardboard with a 0.0445 inch (1.13 mm) caliper.
[0221] Preparation of materials Measure and cut the aluminum oxide cloth to a length of 7.5 inches (19.0 cm). Measure and cut a strip of 3M #3187 tape to a length of 6.5 inches (16.5 cm) (2 strips of tape for each sample strip). Fold both ends of the 3M #3187 tape under approximately 0.25 inches (0.6 cm) for easier handling. Place the 3M #3187 tape on a thick release paper for future use.
[0222] Sample preparation Before handling or testing any material, wash your hands with soap and water to remove excess oils from your hands. Rubber gloves may be worn if necessary. Cut the nonwoven sample to be tested to a size of at least 11 cm in the MD and 4 cm in the CD. Lay the nonwoven sample to be tested flat with the side to be tested facing down. Cut at least 11 cm of 3M#409 double-sided tape from the roll. Peel off the backing and apply the side of the double-sided tape that was facing the backing to the sample nonwoven lengthwise in the machine direction (MD). Place the backing over the exposed tape. Using a paper cutter, cut the test sample within the taped area of 11 cm in the MD and 4 cm in the CD.
[0223] Test procedure 1. Place a piece of aluminum oxide cloth on the Sutherland ink rub tester using a 2 lb weight. Place a second piece of aluminum oxide cloth on top of the heavy release liner cardboard (use a new piece for each test). Place both on top of the 2 lb weight. Bend each side into the shape of a paper clip (so that the aluminum oxide cloth and the heavy release liner cardboard are flat). 2. Place the sample on the platform of the Sutherland Ink Rub Tester, centered over the metal plate. Place a 2200g weight on top of the sample for 20 seconds. 3. Attach the metal plate and 2 lb weight to the Sutherland Ink Rub Tester. 4. Run the friction tester. If the counter light does not come on, press the reset button. Press the counter button to set the friction cycles to 20 cycles. Use the speed buttons to select speed 1, which is a slow speed (no light will come on). Press "Start." 5. Once the friction tester has stopped, carefully remove the aluminum oxide cloth / weight, being careful not to lose any loose microfibers (fuzz). In some cases, the microfibers will be attached to both the aluminum oxide cloth and the surface of the sample nonwoven. Turn the weight upside down and place it on the bench. 6. Weigh the fiber removal tape with the release paper still attached. Pinch the folded end of the fiber removal tape to remove the release paper and set aside. Gently place the tape on an aluminum oxide cloth to remove any fuzz. Remove the fiber removal tape and replace it on the release paper. Weigh the fiber removal tape and record the weight. 7. Pinch the folded end of another pre-weighed piece of fiber removal tape. Gently place this fiber removal tape onto the surface of the rubbed nonwoven sample. Place a flat metal plate on top of the fiber removal tape. 8. Place a 200 g weight on the metal plate for 20 seconds. Remove the fiber removal tape. Pinch the folded edge of the pre-weighed fiber removal tape to avoid fingerprints. Replace the pre-weighed fiber removal tape on the release paper. Weigh the fiber removal tape and record the weight. 9. The weight of the fluff is the sum of the weight increments of both fiber removal tapes. 10. Report the fuzz weight as the average of 10 measurements.
[0224] calculation For a given sample, add the weight (g) of fluff recovered from the aluminum oxide cloth and the weight (g) of fluff recovered from the abraded sample nonwoven. Multiply the total weight (g) by 1000 to convert to milligrams (mg). To convert this measurement from absolute weight loss to weight loss per unit area, divide the total weight of fluff by the area of the abraded region.
[0225] Air Permeability Test The air permeability test is used to measure the amount of air flow in cubic feet per minute (cfm) through the forming belt. Air permeability tests were performed with a Textest Instruments model FX3360 Portair air permeability tester, available from Textest AG, Sonnenbergstrasse 72, CH8603, Schwerzenbach, Switzerland. This instrument uses a 20.7 mm orifice plate for air permeabilities ranging from 300 to 1000 cfm. If the air permeability is less than 300 cfm, a smaller orifice plate is required. If the air permeability is greater than 1000 cfm, a larger orifice plate is required. By measuring the air permeability in localized areas of the forming belt, differences in air permeability across the forming belt can be determined.
[0226] Test procedure 1. Start the FX3360 device. 2. Select the default method, which has the following settings: a. Material: Standard b. Measurement characteristics: Air permeability (AP) c. Test pressure: 125 Pa (Pascal) dT coefficient: 1.00 e. Test point pitch: 0.8 inches. 3. Place a 20.7 mm orifice plate at the desired location on the top side of the forming belt (the side with the three-dimensional projections). 4. Select "Spot Measurement" on the tester touch screen. 5. If necessary, reset the sensor before taking measurements. 6. After resetting, select the "Start" button to begin measurement. 7. Wait until the readings stabilize and record the cfrm reading on the screen. 8. Select the "Start" button again to stop the measurement.
[0227] Bag stacking height test The stack height of a package of absorbent articles within a bag is determined as follows.
[0228] device A thickness tester is used that has a flat rigid horizontal sliding plate. The thickness tester is configured such that the horizontal sliding plate is free to move vertically while always maintaining a horizontal orientation just above a flat rigid horizontal base plate. The thickness tester includes a device suitable for measuring the gap between the horizontal sliding plate and the horizontal base plate to within ±0.5 mm. The horizontal sliding plate and the horizontal base plate are larger than the surface of the absorbent article package that contacts each plate (i.e., each plate extends beyond the contact surface of the absorbent article package in all directions). The horizontal sliding plate exerts a downward force of 850±1 grams force (8.34 N) on the absorbent article package, which may be achieved by placing a suitable weight in the center of the top surface of the horizontal sliding plate that does not contact the package, such that the total mass of the sliding plate plus the additional weight is 850±1 grams.
[0229] Test procedure The absorbent article packages are equilibrated at 23±2° C. and 50±5% relative humidity prior to measurement.
[0230] Raise the horizontal sliding plate and center the absorbent article package under it with the absorbent articles in the package oriented horizontally (see Figure 27). Any handles or other packaging features on the surface of the package that would contact either of the plates are folded flat against the surface of the package to minimize their effect on the measurement. Slowly lower the horizontal sliding plate until it touches the top surface of the package and then release it. 10 seconds after releasing the horizontal sliding plate, measure the gap between the horizontal plates to within ±0.5mm. Five identical packages (same size package and same number of absorbent articles) are measured and the arithmetic mean is reported as the package width. Calculate "in-bag stack height" = (package width / number of absorbent articles per stack) x 10 and report within ±0.5mm.
[0231] Measurement method of intensive properties using micro-CT This method for measuring intensive properties by micro-CT involves measuring values of basis weight, thickness and volume density within visually distinct areas of a substrate sample. The method is based on the analysis of 3D X-ray sample images obtained with a micro-CT instrument (a suitable instrument is the Scanco μCT 50, available from Scanco Medical AG, Switzerland, or an equivalent instrument). The micro-CT instrument is a cone-beam microtomograph with a shielded cabinet. A maintenance-free X-ray tube is used as the source with an adjustable focal spot diameter. The X-ray beam passes through the sample, and a portion of the X-rays is attenuated by the sample. The degree of attenuation correlates with the mass of material through which the X-rays must pass. The transmitted X-rays are incident on a digital detector array, which produces a 2D projection image of the sample. The 3D image of the sample is produced by collecting multiple individual projection images of a rotated sample and then reconstructing these projection images into a single 3D image. The instrument is interfaced with software running on a computer to control the image acquisition and store the raw data. The 3D images are then analyzed by image analysis software (suitable image analysis software is MATLAB, available from The Mathworks, Inc., Natick, Massachusetts, or equivalent) to measure intensive properties of basis weight, thickness, and volume density of regions within the sample.
[0232] Sample preparation: To obtain the sample for measurement, a layer of the dry substrate material is laid flat and a circular piece 30 mm in diameter is punched out.
[0233] If the substrate material is a layer of an absorbent article, such as a topsheet, backsheet nonwoven, acquisition layer, distribution layer, or other component layer, the absorbent article is taped to a hard flat surface in a planar configuration. The individual substrate layers are carefully separated from the absorbent article. If necessary, a scalpel and / or a cryo-spray (Cyto-Freeze from Control Company, Houston TX) can be used to remove the substrate layer from further underlying layers to prevent longitudinal and lateral extension of the material. Once the substrate layer has been removed from the article, samples are punched out as described above.
[0234] If the substrate material is in the form of a wet wipe, open a new package of wet wipes and remove the entire stack from the package, remove one wipe from the middle of the stack, lay it flat and allow it to dry completely before die cutting a sample for analysis.
[0235] Samples can be cut from any location that contains a visually distinct area for analysis. The area for analysis within a region is an area associated with a three-dimensional feature that defines a microregion. A microregion includes at least two visually distinct areas. A region, three-dimensional feature, or microregion can be visually distinct due to varying texture, height, or thickness. Regions within different samples taken from the same substrate material can be analyzed and compared to each other. When selecting the location for taking the sample, care should be taken to avoid folds, wrinkles, or tears.
[0236] Acquire images: The micro-CT device is prepared and calibrated according to the manufacturer's specifications. The sample is placed in a suitable holder between two rings of low density material with an inner diameter of 25 mm. This allows the central portion of the sample to be horizontally positioned and scanned without any other material directly adjacent to its top and bottom surfaces. Measurements should be taken in this area. The field of view of the 3D image is approximately 35 mm on each side in the XY plane, has a resolution of approximately 5000 x 5000 pixels, and a sufficient number of 7 μm thick slices are collected to completely encompass the Z direction of the sample. The reconstructed 3D image resolution contains 7 μm isotropic voxels. Images are acquired using a 45 kVp, 133 μA power supply without further low energy filtering. These current and voltage settings can be optimized to allow sufficient x-rays to penetrate the sample to maximize contrast in the projection data, but once optimized, are kept constant for all substantially similar samples. A total of 1500 projection images are acquired with an integration time of 1000 ms and 3 averages. These projection images are reconstructed into 3D images and stored in 16-bit RAW format to preserve the complete detector output signal for analysis.
[0237] Image Processing: Load the 3D image into image analysis software. Set the threshold of the 3D image to a value that isolates and removes background signal due to air, but preserves signal from the sample fibers within the substrate.
[0238] Three 2D intensive property images are generated from the thresholded 3D image. The first is a basis weight image. To generate this image, the value of each voxel in a slice in the XY plane is summed with all of the corresponding voxel values in other Z slices that contain signal from the sample. This generates a 2D image in which each pixel has a value equal to the cumulative signal throughout the sample.
[0239] A basis weight calibration curve is generated to convert the raw data values in the basis weight image to actual values. A substrate having substantially similar composition as the sample to be analyzed and uniform basis weight is obtained. At least 10 replicate samples of the calibration curve substrate are obtained according to the procedure described above. The basis weight of each of the single layer calibration samples is accurately measured by measuring the mass to the nearest 0.0001 g, dividing by the area of the sample, and converting to grams per square meter (gsm), and the average is calculated to the nearest 0.01 gsm. A micro-CT image of a single layer of the calibration sample substrate is obtained according to the procedure described above. The micro-CT image is processed according to the procedure described above to generate a basis weight image including raw data values. The actual basis weight value of the sample is the average basis weight value measured on the calibration sample. Two layers of the calibration substrate sample are then stacked on top of each other, and a micro-CT image of the two layers of the calibration substrate is obtained. A raw data image of the combined basis weight of both layers is generated. The actual basis weight value is equal to twice the average basis weight value measured on the calibration sample. The procedure is repeated by stacking single-ply calibration substrates, acquiring micro-CT images of all layers, and generating raw data basis weight images of all layers whose actual basis weight values are equal to the number of layers multiplied by the average basis weight value measured on the calibration samples. In total, at least four different basis weight calibration images are obtained. To ensure an accurate calibration, the basis weight values of the calibration samples should include values above and below the basis weight values of the original samples being analyzed. A calibration curve is generated by performing a linear regression of the raw data against the actual basis weight values for the four calibration samples. This linear regression should have an R2 value of at least 0.95, otherwise the entire calibration procedure is repeated. This calibration curve is then used to convert the raw data values to actual basis weights.
[0240] The second intensive property 2D image is the thickness image. To generate this image, the top and bottom surfaces of the sample are identified and the distance between these surfaces is calculated to obtain the thickness of the sample. The top surface of the sample is identified by locating a voxel in the Z direction for every pixel location in the XY plane where a sample signal was first detected, starting with the top Z slice and proceeding through the sample to evaluate each slice. To identify the bottom surface of the sample, the same procedure is followed except that the Z voxels located are every location in the XY plane where a sample signal was last detected. Once the top and bottom surfaces have been identified, they are smoothed with a 15x15 median filter to remove signal from stray fibers. A 2D thickness image is then generated by counting the number of voxels that lie between the top and bottom surfaces for each pixel location in the XY plane. This raw thickness value is then converted to an actual distance in μm by multiplying the voxel count by the thickness resolution of the 7 μm slice.
[0241] The third intensive property 2D image is the volume density image. To generate this image, each pixel value in the XY plane in the basis weight image in gsm is divided by the corresponding pixel in the thickness image in μm. The volume density image has units of g / cubic centimeter (g / cc).
[0242] Intensive properties of basis weight, thickness, and volume density by micro-CT: The analysis begins by identifying an area to be analyzed. The area to be analyzed is an area associated with a three-dimensional feature that defines a microregion. A microregion includes at least two visually distinct areas. A region, three-dimensional feature, or microregion may be visually distinct due to varying texture, height, or thickness. The boundaries of the area to be analyzed are then identified. The boundaries of the area are identified by visually distinguishing differences in intensive properties when compared to other areas in the sample. For example, the boundaries of the area can be identified based on visually distinguishing differences in thickness when compared to another area of the sample. Any intensive property can be used to distinguish the boundaries of the area on the physical sample itself of any of the microCT intensive property images. Once the boundaries of the area are identified, an oval or circular "region of interest" (ROI) is drawn inside the area. The ROI should be at least 0.1 mm. 2 The area of the ROI should be selected to measure, with intensive property values representative of the identified region. From each of the three intensive property images, calculate the average basis weight, thickness, and volume density within the ROI. Record these values for the region to the nearest 0.01 gsm for basis weight, 0.1 μm for thickness, and 0.0001 g / cc for volume density.
[0243] Emtec Test Method The TS7 and TS750 values are measured using an EMTEC Tissue Softness Analyzer ("Emtec TSA") (Emtec Electronic GmbH, Leipzig, Germany) connected to a computer running Emtec TSA software (version 3.19 or equivalent). According to Emtec, the TS7 value correlates to the actual material softness and the TS750 value correlates to the felt smoothness / roughness of the material. The Emtec TSA has a rotor with a vertical blade that rotates on the test specimen at a defined calibrated rotation speed (set by the manufacturer) and a contact force of 100 mN. Contact between the vertical blade and the test specimen creates vibrations that generate sounds that are recorded by a microphone in the instrument. The recorded sound files are then analyzed by the Emtec TSA software. Sample preparation, instrument operation, and test procedures are performed according to the instrument manufacturer's specifications.
[0244] Sample preparation Test samples are prepared by cutting square or circular samples from the final product. Test samples are cut (in either of these dimensions) to lengths and widths (or diameters, if circular) of no less than about 90 mm and no more than about 120 mm so that the sample can be properly secured within the TSA instrument. Test samples are selected to be free of perforations, wrinkles, or creases within the test area. Eight substantially similar replicate samples are prepared for testing. All samples are equilibrated at TAPPI standard temperature and relative humidity conditions (23°C ± 2°C and 50% ± 2%) for at least two hours prior to conducting the TSA test. TSA testing is also conducted under TAPPI conditions.
[0245] Test procedure Calibrate the instrument according to the manufacturer's instructions using a one-point calibration method with Emtec reference standards ("Reference 2"). In the absence of these references, use appropriate references provided by the manufacturer. Calibrate the instrument according to the manufacturer's recommendations and instructions so that results are comparable to those obtained using a one-point calibration method with Emtec reference standards ("Reference 2").
[0246] Provide eight replicate samples of the fabric for testing. Mount the test samples, one side up, in the fixture and perform the test according to the manufacturer's instructions. Once the test is complete, the software will display the TS7 and TS750 values. Increment each of these values by 0.01 dB V 2 The results are recorded in rms units. The test sample is then removed from the apparatus and disposed of. The test is performed separately on the same surface of four of the replicate samples and then on the other surface of the other four replicate samples. The first test surface can be either the first surface 12 or the second surface 14 of the shaped nonwoven fabric disclosed herein.
[0247] Average (use simple numerical averaging) the four TS7 and TS750 test result values from the first test surface. Repeat the same procedure for the four TS7 and TS750 test result values from the second test surface. For both the first and second test surfaces of a particular test specimen, average the individual TS7 and TS750 results to within 0.01 dB V 2 Report in rms units. Additionally, the ratio of TS7 of the first test surface to the second test surface is calculated by dividing the average TS7 of the first test surface by the average TS7 of the second test surface.
[0248] Contact Angle and Wick Time Test Method Contact angle and wick time measurements are determined using a sessile drop experiment. A specific amount of type II reagent distilled water (defined in ASTM D1193) is applied to the surface of the test specimen using an automated liquid delivery system. A high-speed video camera captures time-stamped images of the droplet over a period of 60 seconds at a rate of 900 frames per second. The contact angle between the droplet and the surface of the test specimen is determined for each captured image by image analysis software. The wick time is determined as the time it takes for the contact angle of a droplet absorbed into the test specimen to decrease to a contact angle <10°. All measurements are performed at constant temperature (23°C ± 2°C) and relative humidity (50% ± 2%).
[0249] To perform this test, an automated contact angle tester is required. The system consists of a light source, a video camera, a horizontal sample stage, a liquid delivery system with pump and microsyringe, and a computer with suitable software for video image capture, image analysis, and reporting of contact angle data. A suitable instrument is the Optical Contact Angle Measurement System OCA 20 (Data Physics Instruments, Filderstadt, Germany), or equivalent. The system must be capable of delivering an 8.2 μL droplet and capturing images at a rate of 900 frames per second. Unless otherwise specified in this test procedure, the system is calibrated and operated according to the manufacturer's instructions.
[0250] To obtain a test sample for measurement, lay a single layer of dry substrate material flat and cut out a rectangular test sample 15 mm wide and approximately 70 mm long. The width of the sample may be reduced as necessary to ensure that the test area of interest is not obscured by surrounding features during testing. Care should be taken with narrow sample pieces to ensure that droplets do not reach the edge of the test sample during testing, otherwise the test will need to be repeated. Precondition the sample for 2 hours at 23°C ± 2°C and 50% ± 2% relative humidity prior to testing.
[0251] Sample preparation The test sample can be cut from any location that contains a visually distinct area for analysis. The area for analysis within a region is an area associated with a three-dimensional feature that defines a microregion. A microregion includes at least two visually distinct areas. A region, three-dimensional feature, or microregion can be visually distinct due to varying texture, height, or thickness. Regions within different test samples taken from the same substrate material can be analyzed and compared to each other. When selecting the location for taking the sample, care should be taken to avoid folds, wrinkles, or tears.
[0252] If the substrate material is a layer of an absorbent article, such as a topsheet or backsheet nonwoven, acquisition layer, distribution layer, or other component layer, tape the absorbent article to a solid flat surface to form a flat surface. Carefully separate the individual substrate layers from the absorbent article. If necessary, a scalpel and / or a cold spray (Cyto-Freeze from Control Company, Houston TX) can be used to remove the substrate layer from further underneath, preventing the material from extending lengthwise and widthwise. Once the substrate layer is removed from the article, proceed to cut the test samples. If the substrate material is in the form of a wet wipe, open a new package of wet wipes and remove the entire stack from the package. Remove one wipe from the middle of the stack, lay it flat and allow it to dry completely before cutting out a sample for analysis.
[0253] Test procedure The test sample is placed on a horizontal sample stage with the test surface facing up and the test area within the camera's field of view below the liquid delivery system needle. The test sample is fixed so that it is flat but not distorted, and all interaction between the droplet and the underlying surface is avoided to prevent excessive capillary forces. A 27-gauge blunt-tip stainless steel needle (ID 0.23 mm, OD 0.41 mm) is placed above the test sample with at least 2 mm of the needle tip within the camera's field of view. The sample stage is adjusted so that there is a distance of approximately 3 mm between the tip of the needle and the surface of the test sample. An 8.2 μL droplet of reagent distilled water is formed at a rate of 1 μL per second and allowed to free fall onto the surface of the test sample. Video image capture is initiated before the droplet contacts the surface of the test sample, followed by a continuous series of images collected for 60 seconds after the droplet contacts the surface of the test sample. This procedure is repeated for a total of five substantially similar replicate test areas. Use a new test sample or ensure that the wetted area of the previous droplet is avoided during subsequent measurements.
[0254] On each image captured by the video camera, the test sample surface and the outline of the droplet are identified and used by image analysis software to calculate the contact angle for each droplet image, reported to the nearest 0.1 degrees. The contact angle is the angle formed by the surface of the test sample, tangent to the surface of the droplet in contact with the test sample. For each series of images from the test, time zero is the time the droplet contacts the surface of the test sample. The contact angle of the droplet image for a time of zero plus 5 seconds is measured and recorded. The contact angle at 5 seconds is reported as 0° if the droplet is completely absorbed by the test sample within 5 seconds. This procedure is repeated for five replicate test areas. The arithmetic mean of the contact angles for a time of zero plus 5 seconds for the five replicate test areas is calculated, and this value is reported as the contact angle to the nearest 0.1 degrees.
[0255] Wick time is defined as the time it takes for the contact angle of a droplet absorbed into the test sample to decrease to a contact angle of <10°. Wick time is measured by identifying the first image in a given series where the contact angle decreases to a contact angle <10°, and then calculating and reporting the amount of time that has elapsed from time zero based on that image. If a contact angle of less than 10° is not reached within 60 seconds, the wick time is reported as 60 seconds. This procedure is repeated for five replicate test areas. The arithmetic mean of the wick times for the five replicate test areas is calculated and this value is reported to the nearest 0.1 millisecond.
[0256] The invention of the present disclosure can be described by any of the following combinations, which are detailed in the following paragraphs: A. A spunbond nonwoven fabric, a. a first surface and a second surface and at least first and second visually distinguishable areas on at least one of the first and second surfaces, each of the first and second areas having a pattern of three-dimensional features, each of the three-dimensional features defining a microarea including a first region and a second region, the first and second regions having a difference in value of an intensive property; b. the difference in the value of the intensive property in at least one of the microzones in the first region is different from the difference in the value of the intensive property in at least one of the microzones in the second region; A spunbond nonwoven fabric, wherein in at least one of the microregions, a first region is hydrophobic and a second region is hydrophilic. B. The spunbond nonwoven fabric of paragraph A, wherein the difference in value of the intensive property in one of the microzones in the first region is an order of magnitude different from the difference in value in at least one of the microzones in the second region. C. The spunbond nonwoven fabric of paragraph A or B, wherein the difference in value of the intensive property in one of the microzones in the first region differs from the difference in value in at least one of the microzones in the second region by about 1.2X to about 10X. D. The spunbond nonwoven fabric of paragraphs A-C, wherein the intensive property is thickness, and all regions have a thickness greater than 0. E. The spunbond nonwoven fabric of paragraphs A-D, wherein the difference in thickness within the first region is greater than about 25 μm. F. The spunbond nonwoven fabric of paragraphs A-E, wherein the intensive property is basis weight, and all regions have a basis weight greater than zero. G. The spunbond nonwoven fabric of paragraphs A-F, wherein the difference in basis weight within the first region is greater than about 5 gsm. H. The spunbond nonwoven fabric of paragraphs A through G, wherein the intensive property is volume density, and the volume density of all regions is greater than 0. I. The spunbond nonwoven fabric of paragraphs AH, wherein the difference in bulk density within the first region is greater than about 0.042 g / cc. J. The spunbond nonwoven fabric of paragraphs A-I, further comprising a third region having a pattern of three-dimensional features defining microzones each including a first region and a second region, wherein a difference in value of the intensive property in one of the microzones in the third region is a) different from the difference in value of the intensive property in at least one of the microzones in the first region, and b) different from the difference in value of the intensive property in at least one of the microzones in the second region. K. At least one of the surfaces is approximately 15 dBV 2 The spunbond nonwoven fabric of paragraphs A-J, having a TS7 value of less than rms. L. The first surface is about 2 to about 12 dBV 2 The spunbond nonwoven fabric of paragraph K, wherein the first surface has an rms TS7 value and the second surface has a different TS7 value than the TS7 value of the first surface. M. The spunbond nonwoven fabric of paragraph L, wherein the second surface has a TS7 value that is lower than the TS7 value of the first surface. N. The spunbond nonwoven fabric of paragraph K, wherein the second surface has a TS7 value from about 3 to about 8, and the first surface has a TS7 value that is different from the TS7 value of the first surface. O. The spunbond nonwoven fabric of paragraph N, wherein the first surface has a TS7 value that is higher than the TS7 value of the second surface. P. An absorbent article comprising the spunbond nonwoven fabric described in paragraphs A-O. Q. A package of absorbent articles, each absorbent article comprising the spunbond nonwoven fabric described in paragraphs A-P. R. The package of paragraph Q, wherein the package has an In-Bag Stacking Height of about 70 mm to about 100 mm, according to the In-Bag Stacking Height Test herein. S. A spunbond nonwoven fabric, a. a first surface and a second surface and at least first and second visually distinguishable areas on at least one of the first and second surfaces, each of the first and second areas having a pattern of three-dimensional features, each of the three-dimensional features defining a microarea including a first region and a second region, the first and second regions having a difference in value of an intensive property; b. the difference in the value of the intensive property in at least one of the microzones in the first region is different from the difference in the value of the intensive property in at least one of the microzones in the second region; In at least one of the microregions, the second region comprises a surfactant and the first region does not comprise a surfactant. T. The surfactants are non-ionic surfactants including esters, amides, carboxylic acids, alcohols, ether-polyoxyethylenes, polyoxypropylenes, sorbitans, ethoxylated fatty alcohols, allylphenol polyethoxylates, lecithins, glycerol esters and their ethoxylates, and sugar-based surfactants (polysorbates, polyglycosides); anionic surfactants including sulfonates, sulfates, phosphates, alkali metal salts of fatty acids, fatty alcohol monoesters of sulfuric acid, linear alkylbenzene sulfonates, alkyl diphenyl oxide sulfonates, lignin sulfonates, olefin sulfonates, sulfosuccinates, and sulfated ethoxylates of fatty alcohols; amines. The spunbond nonwoven fabric of paragraph S, wherein the surfactant is selected from the group consisting of cationic surfactants including (primary, secondary, tertiary), quaternary ammonium, pyridinium, quaternary ammonium salts-quats, alkylated pyridinium salts, alkyl primary, secondary, tertiary amines, and alkanolamides; zwitterionic surfactants including amino acids and derivatives, amine oxides, betaines, and alkylamine oxides; polymeric surfactants including polyamines, carboxylic acid polymers and copolymers, EO / PO block copolymers, ethylene oxide polymers and copolymers, and polyvinylpyrrolidone; dimethylsiloxane polymers having hydrophilic properties, and silicone surfactants including perfluorocarboxylates and fluorosurfactants. U. The spunbond nonwoven fabric of paragraph S or T, wherein the surfactant is a combination of castor oil ethoxylate and a PEG diester. V. The spunbond nonwoven fabric of paragraphs S-U, wherein the difference in value of the intensive property in one of the microzones in the first region is an order of magnitude different from the difference in value in at least one of the microzones in the second region. W. The spunbond nonwoven fabric of paragraphs S-V, wherein the difference in value of the intensive property in one of the microzones in the first region differs from the difference in value in at least one of the microzones in the second region by about 1.2X to about 10X. X. The spunbond nonwoven fabric of paragraphs S through W, wherein the intensive property is thickness and all regions have a thickness greater than zero. Y. The spunbond nonwoven fabric of paragraphs S through X, wherein the difference in thickness within the first region is greater than about 25 μm. Z. The spunbond nonwoven fabric of paragraphs S through Y, wherein the intensive property is basis weight, and all regions have a basis weight greater than zero. AA. The spunbond nonwoven fabric of paragraphs S-Z, wherein the difference in basis weight within the first region is greater than about 5 gsm. BB. The spunbond nonwoven fabric of paragraphs S-AA, wherein the intensive property is volume density, and the volume density of all regions is greater than 0. CC. The spunbond nonwoven fabric of paragraphs S-BB, wherein the difference in bulk density within the first region is greater than about 0.042 g / cc. DD. The spunbond nonwoven fabric of paragraphs S-CC, further comprising a third region having a pattern of three-dimensional features each defining a microregion including a first region and a second region, wherein a difference in value of the intensive property in one of the microregions in the third region is a) different from the difference in value of the intensive property in at least one of the microregions in the first region, and b) different from the difference in value of the intensive property in at least one of the microregions in the second region. At least one of the EE surfaces is approximately 15 dBV 2 The spunbond nonwoven fabric of paragraphs S-DD, having a TS7 value of less than rms. FF. The first surface is about 2 to about 12 dB V 2 The spunbond nonwoven fabric of paragraph EE, having an rms TS7 value and the second surface having a different TS7 value than the TS7 value of the first surface. GG. The spunbond nonwoven fabric of paragraph FF, wherein the second surface has a TS7 value that is lower than the TS7 value of the first surface. HH. The spunbond nonwoven fabric of paragraph EE, wherein the second surface has a TS7 value from about 3 to about 8, and the first surface has a TS7 value that is different from the TS7 value of the first surface. II. The spunbond nonwoven fabric of paragraph HH, wherein the first surface has a higher TS7 value than the TS7 value of the second surface. An absorbent article comprising the spunbond nonwoven fabric described in JJ. paragraphs S-II. KK. A package of absorbent articles, each absorbent article comprising the spunbond nonwoven fabric described in paragraphs S-JJ. LL. The package of paragraph KK, wherein the package has an In-Bag Stacking Height of about 70 mm to about 100 mm, according to the In-Bag Stacking Height Test herein. MM. A spunbond nonwoven fabric comprising: a. a first surface and a second surface and at least first and second visually distinguishable areas on at least one of the first and second surfaces, each of the first and second areas having a pattern of three-dimensional features, each of the three-dimensional features defining a microarea including a first region and a second region, the first and second regions having a difference in value of an intensive property; b. the difference in the value of the intensive property in at least one of the microzones in the first region is different from the difference in the value of the intensive property in at least one of the microzones in the second region; A spunbond nonwoven fabric, wherein in at least one of the microregions, the first and second regions comprise a surfactant, and the ratio of the % surfactant in the first region to the % surfactant in the second region is less than 1. NN. The surfactants are nonionic surfactants including esters, amides, carboxylic acids, alcohols, ether-polyoxyethylenes, polyoxypropylenes, sorbitans, ethoxylated fatty alcohols, allylphenol polyethoxylates, lecithins, glycerol esters and their ethoxylates, and sugar-based surfactants (polysorbates, polyglycosides); anionic surfactants including sulfonates, sulfates, phosphates, alkali metal salts of fatty acids, fatty alcohol monoesters of sulfuric acid, linear alkylbenzene sulfonates, alkyl diphenyl oxide sulfonates, lignin sulfonates, olefin sulfonates, sulfosuccinates, and sulfated ethoxylates of fatty alcohols; amines. The spunbond nonwoven of paragraph MM, wherein the surfactant is selected from the group consisting of cationic surfactants including (primary, secondary, tertiary), quaternary ammonium, pyridinium, quaternary ammonium salts-quats, alkylated pyridinium salts, alkyl primary, secondary, tertiary amines, and alkanolamides; zwitterionic surfactants including amino acids and derivatives, amine oxides, betaines, and alkylamine oxides; polymeric surfactants including polyamines, carboxylic acid polymers and copolymers, EO / PO block copolymers, ethylene oxide polymers and copolymers, and polyvinylpyrrolidone; dimethylsiloxane polymers having hydrophilic properties, and silicone surfactants including perfluorocarboxylates and fluorosurfactants. OO. The spunbond nonwoven of paragraphs MM or NN, wherein the surfactant is a combination of castor oil ethoxylate and a PEG diester. PP. The spunbond nonwoven fabric of paragraphs MM-OO, wherein the difference in value of the intensive property in one of the microzones in the first region is an order of magnitude different from the difference in value in at least one of the microzones in the second region. QQ. The spunbond nonwoven fabric of paragraphs MM-PP, wherein the difference in value of the intensive property in one of the microzones in the first region differs from the difference in value in at least one of the microzones in the second region by about 1.2X to about 10X. RR. The spunbond nonwoven fabric of paragraphs MM-QQ, wherein the intensive property is thickness and all regions have a thickness greater than 0. SS. The spunbond nonwoven fabric of paragraphs MM-RR, wherein the difference in thickness within the first region is greater than about 25 μm. TT. The spunbond nonwoven fabric of paragraphs MM-SS, wherein the intensive property is basis weight, and wherein all regions have a basis weight greater than 0. UU. The spunbond nonwoven fabric of paragraphs MM-TT, wherein the difference in basis weight within the first region is greater than about 5 gsm. VV. The spunbond nonwoven fabric of paragraphs MM-UU, wherein the intensive property is volume density, and the volume density of all regions is greater than 0. WW. The spunbond nonwoven fabric of paragraphs MM-VV, wherein the difference in bulk density within the first region is greater than about 0.042 g / cc. XX. The spunbond nonwoven fabric of paragraphs MM-WW, further comprising a third region having a pattern of three-dimensional features defining microregions each including a first region and a second region, wherein a difference in value of the intensive property in one of the microregions in the third region is a) different from the difference in value of the intensive property in at least one of the microregions in the first region, and b) different from the difference in value of the intensive property in at least one of the microregions in the second region. At least one of the YY surfaces is approximately 15 dBV 2 The spunbond nonwoven fabric of paragraphs MM-XX, having a TS7 value of less than rms. ZZ. The first surface is about 2 to about 12 dBV 2 The spunbond nonwoven fabric of paragraph YY, wherein the second surface has a TS7 value that is different from the TS7 value of the first surface. AAA. The spunbond nonwoven fabric of paragraph ZZ, wherein the second surface has a TS7 value lower than the TS7 value of the first surface. BBB. The spunbond nonwoven fabric of paragraph YY, wherein the second surface has a TS7 value from about 3 to about 8, and the first surface has a TS7 value that is different from the TS7 value of the first surface. CCC. The spunbond nonwoven fabric of paragraph BBB, wherein the first surface has a TS7 value that is higher than the TS7 value of the second surface. DDD. An absorbent article comprising the spunbond nonwoven fabric described in paragraphs MM-CCC. EEE. A package of absorbent articles, each absorbent article comprising the spunbond nonwoven fabric described in paragraphs MM-DDD. The package of paragraph EEE, wherein the package has an In-Bag Stacking Height of about 70 mm to about 100 mm, according to the In-Bag Stacking Height Test herein. GGG. A nonwoven fabric comprising a first surface and a second surface and a visually distinguishable pattern of three-dimensional features on one of the first or second surfaces, each of the three-dimensional features defining a microregion comprising a first region and a second region, the first and second regions having a difference in value of an intensive property, the intensive property being: a.Thickness, b. Basis weight, and c. volume density; A nonwoven fabric, wherein in at least one of the microregions, a first region is hydrophobic and a second region is hydrophilic. HHH. The nonwoven fabric of paragraph GGG, wherein the difference in value of the intensive property in one of the microzones in the first region is an order of magnitude different from the difference in value in at least one of the microzones in the second region. III. The nonwoven fabric of paragraph GGG or HHH, wherein the difference in value of the intensive property in one of the microzones in the first region differs from the difference in value in at least one of the microzones in the second region by about 1.2X to about 10X. JJJ. The nonwoven fabric of paragraphs GGG-III, wherein the intensive property is thickness and all regions have a thickness greater than zero. KKK. The nonwoven fabric of paragraphs GGG-JJJ, wherein the difference in thickness within the first region is greater than about 25 μm. LLL. The nonwoven fabric of paragraphs GGG-KKK, wherein the intensive property is basis weight, and all regions have a basis weight greater than 0. MMM. The nonwoven fabric of paragraphs GGG-LLL, wherein the difference in basis weight within the first region is greater than about 5 gsm. NNN. The nonwoven fabric of paragraphs GGG-MMM, wherein the intensive property is volume density, and all regions have a volume density greater than 0. OOO. The nonwoven fabric of paragraphs GGG-NNN, wherein the difference in bulk density within the first region is greater than about 0.042 g / cc. At least one of the PPP surfaces is approximately 15 dBV 2 The nonwoven fabric of paragraphs GGG-OOO, having a TS7 value of less than rms. QQQ. The first surface is about 2 to about 12 dBV 2 and the second surface has a TS7 value that is different from the TS7 value of the first surface. RRR. The nonwoven fabric of paragraph QQQ, wherein the second surface has a TS7 value that is lower than the TS7 value of the first surface. SSS. The nonwoven fabric of paragraph PPP, wherein the second surface has a TS7 value from about 3 to about 8, and the first surface has a TS7 value that is different from the TS7 value of the first surface. TTT. The nonwoven fabric of paragraph SSS, wherein the first surface has a TS7 value that is higher than the TS7 value of the second surface. UUU. An absorbent article comprising the nonwoven fabric of paragraphs GGG-TTT. VVV. A package of absorbent articles, each absorbent article comprising the nonwoven fabric of paragraphs GGG-VVV. WWW. The package of paragraph VVV, wherein the package has an In-Bag Stacking Height of about 70 mm to about 100 mm according to the In-Bag Stacking Height Test herein. XXX. The nonwoven fabric of paragraphs GGG-WWW, wherein the nonwoven fabric is a spunbond construction.
[0257] Dimensions and values disclosed herein should not be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."
[0258] All documents cited herein, including all cross-referenced or related patents or patent applications, and any patent applications or patents to which this application claims priority or benefit, are incorporated herein by reference in their entirety, unless expressly excluded or otherwise limited. The citation of any document shall not be deemed to be prior art to any invention disclosed or claimed herein, or to teach, suggest, or disclose such invention, either alone or in combination with any other reference. Furthermore, to the extent that any meaning or definition of a term in this document conflicts with a meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall apply.
[0259] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
Claims
1. 1. A nonwoven fabric comprising a first surface and an opposing second surface, and first and second regions on one of the first or second surfaces, each of the first and second regions having a different pattern of three-dimensional features, each of the three-dimensional features defining a microregion including a first region and a second region, the first and second regions having a difference in value of an intensive property, the intensive property being: a. thickness, b. Basis weight, and c. volume density; In at least one of the microzones, the first region is hydrophobic and the second region is hydrophilic, the first surface has a first TS7 value and the second surface has a second TS7 value, the first TS7 value of the first surface being between 2 and 12 dBV. 2 rms, and a second TS7 value of the second surface is between 3 and 8 dBV. 2 rms, and a first TS7 value of the first surface is different from a second TS7 value of the second surface.
2. 2. The nonwoven fabric of claim 1, wherein the intensive property is thickness and all regions have a thickness greater than 0.
3. 3. The nonwoven fabric of claim 2, wherein the thickness difference within the first region is greater than 25 μm.
4. 2. The nonwoven fabric of claim 1, wherein the intensive property is basis weight, and all regions have a basis weight greater than 0.
5. 5. The nonwoven fabric of claim 4, wherein the difference in basis weight within the first region is greater than 5 gsm.
6. 2. The nonwoven fabric of claim 1, wherein the intensive property is volume density, and the volume density of all regions is greater than 0.
7. 7. The nonwoven fabric of claim 6, wherein the difference in bulk density within the first region is greater than 0.042 g / cc.
8. 10. The nonwoven fabric of claim 1, wherein the second surface has a lower TS7 value than the TS7 value of the first surface.
9. 10. The nonwoven fabric of claim 1, wherein the first surface has a higher TS7 value than the TS7 value of the second surface.
10. An absorbent article comprising the nonwoven fabric of claim 1.
11. The package of absorbent articles according to claim 10.
12. 10. The nonwoven fabric of claim 1, wherein the nonwoven fabric is a spunbond structure.
13. 1. A nonwoven fabric comprising a first surface and an opposing second surface, and first and second regions on one of the first or second surfaces, each of the first and second regions having a different pattern of three-dimensional features, each of the three-dimensional features defining a microregion including a first region and a second region, the first and second regions having a difference in value of an intensive property, the intensive property being: a. thickness, b. Basis weight, and c. volume density; In at least one of the microregions, the first region is hydrophobic and the second region is hydrophilic; The first surface is 2 to 12 dBV 2 a second TS7 value of the second surface being between 3 and 8 dBV 2 rms, and a first TS7 value of the first surface is different from a second TS7 value of the second surface.
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