Absorbent article comprising absorbent core structure having shaped inner core layer

Abstract

A disposable absorbent article having a topsheet, a backsheet, and an absorbent core structure disposed therebetween. The absorbent core structure includes an upper nonwoven layer comprising polymeric fibers, a lower nonwoven layer comprising polymeric fibers, and an inner core layer comprising cellulosic fibers and superabsorbent particles disposed therebetween. The inner core layer is profiled in a longitudinal direction and a transverse direction and is defined by a central absorbent region and an outer absorbent region substantially surrounding the central absorbent region. The basis weight of the central absorption region is greater than the basis weight of the outer absorption region. A plurality of cellulosic fibers of the inner core layer penetrate through the lower surface of the upper nonwoven layer. The upper nonwoven layer has a circular bend of from about 2.5 gf to about 10 gf, as measured according to the circular bending method.

Description

Technical Field

[0001] This disclosure relates to absorbent articles including absorbent core structures having shaped inner core layers. Background Technology

[0002] Absorbent products such as diapers, training pants, feminine pads, and adult incontinence pads are widely used by consumers. Generally, absorbent products like these consist of a top sheet and a bottom sheet, with an absorbent core structure positioned between them. These absorbent products are designed to absorb and retain fluids and other excretions from the body to prevent soiling of the body and clothing. Historically, absorbent core structures used in menstrual pad applications have utilized cellulose fibers in various ways to control the complex and changing rheological properties of menstrual fluid and vaginal secretions. Cellulose-based absorbent core structures are often densified to create thinner products. However, the trade-off for densifying these absorbent systems is reduced comfort (stiffness) and the ability of the absorbent core structure and / or absorbent product to readily conform to its unique anatomical geometry.

[0003] To effectively absorb fluid without leakage, absorbent fabrics used for menstrual applications should closely conform to the anatomy of the female genitalia, allowing them to trap fluid as it leaves the labia. A common complaint among current absorbent fabric users is that during heavy menstrual bleeding, they feel fluid flowing down their body or escaping from the fabric. In the case of products worn over underwear, the underwear and absorbent fabric often do not fit the body tightly enough to address these consumer problems. Historically, absorbent fabrics have attempted to solve this problem by adding more volume (i.e., absorbent material) to fill the space between the user's legs. Other methods involve adding more absorbent material to the center of the absorbent fabric (often called "center thickening") to increase the thickness of the central area. This is typically achieved by shaping the cellulose absorbent material longitudinally or by adding additional discrete elliptical absorbent layers.

[0004] However, these traditional methods fail to adequately address the problem of reducing or eliminating fluid diffusion on the body because the added absorbent material is always bulky, stiff, and cannot be molded to fit the wearer's intimate anatomy in a close and comfortable manner. In the case of the female genitalia, fluid first flows out of the body within the labial vestibule (particularly within the labia minora) before flowing out through the labia majora. Fluid can flow out of the labial structure at the top, bottom, and / or sides. Because the labial vestibule is curved, there are often gaps between the labia majora, so simply adding more absorbent material in the central area does not capture fluid flowing from the labia minora. The traditional "middle thickening" shape is located at the top of the labial structure, thus forming a bridge-like structure across the gap between the labia majora, but it fails to actually capture the fluid remaining within and flowing outward from the labial vestibule. In addition, the typically thickened central area may actually push the non-protruding parts of the absorbent material away from her body, creating more gaps on the sides, allowing fluid diffusion to become noticeable to the consumer.

[0005] Therefore, there is a need for an improved absorbent material that can more effectively capture fluid flowing from the labia minora within the labia majora in a wide variety of female genital shapes and sizes, without causing a feeling of stiffness or bulkiness. Summary of the Invention

[0006] This disclosure addresses the problem of fluid diffusion on the body by providing an absorbent core structure comprising an inner core layer shaped to fit snugly within and between the labia majora and at the base of the perineum and mons pubis. As described herein, absorbent articles include absorbent core structures comprising irregularly shaped inner core layers that are highly compressible and moldable without bulkiness, thereby allowing the absorbent articles to comfortably adapt to and fit snugly to a wide range of female anatomical shapes.

[0007] A disposable absorbent article includes: a top sheet; a bottom sheet; and an absorbent core structure disposed between the top sheet and the bottom sheet. The absorbent core structure includes: (a) an upper nonwoven layer comprising polymer fibers and having a basis weight of about 30 gsm to about 85 gsm, wherein the upper nonwoven layer includes an upper surface and a lower surface opposite to the upper surface; (b) a lower nonwoven layer comprising polymer fibers; and (c) an inner core layer disposed between the upper and lower nonwoven layers, wherein the inner core layer comprises about 50% to about 85% cellulose fibers by weight of the inner core layer, and about 15% to about 50% superabsorbent particles by weight of the inner core layer. The inner core layer also includes a central absorbent region and an outer absorbent region substantially surrounding the central absorbent region, wherein the central absorbent region has a first basis weight and the outer absorbent region has a second basis weight, wherein the first basis weight is greater than the second basis weight. Multiple cellulose fibers of the inner core penetrate the lower surface of the upper nonwoven layer. The upper nonwoven layer has a circular curvature of approximately 2.5 gf to approximately 10 gf, as measured by the circular curvature method.

[0008] A disposable absorbent article includes: a longitudinal axis, a transverse axis, and a z-axis perpendicular to the longitudinal and transverse axes; a top sheet; a bottom sheet; and an absorbent core structure disposed between the top sheet and the bottom sheet. The absorbent core structure includes: (a) an upper nonwoven layer comprising polymer fibers and having a basis weight of about 30 gsm to about 85 gsm; (b) a lower nonwoven layer comprising polymer fibers; and (c) an inner core layer disposed between the upper and lower nonwoven layers, wherein the inner core layer comprises about 50% to about 85% cellulose fibers by weight of the inner core layer, and about 15% to about 50% superabsorbent particles by weight of the inner core layer. The inner core layer includes a central absorbent region and an outer absorbent region substantially surrounding the central absorbent region, wherein the central absorbent region has a first basis weight, and the outer absorbent region has a second basis weight, wherein the first basis weight is greater than the second basis weight. The central absorption region includes a transition region that forms an angle of approximately 2 to approximately 40 degrees relative to the z-axis; the central absorption region includes a pair of inwardly recessed longitudinal sides, an outwardly protruding front edge, and an outwardly protruding rear edge.

[0009] A disposable absorbent article includes: a top sheet; a bottom sheet; and an absorbent core structure disposed between the top sheet and the bottom sheet. The absorbent core structure includes: (a) an upper nonwoven layer comprising polymer fibers and having a basis weight of about 30 gsm to about 85 gsm, wherein the upper nonwoven layer includes an upper surface and a lower surface opposite to the upper surface; (b) a lower nonwoven layer comprising polymer fibers; and (c) an inner core layer disposed between the upper and lower nonwoven layers, wherein the inner core layer comprises about 50% to about 85% cellulose fibers by weight of the inner core layer, and about 15% to about 50% superabsorbent particles by weight of the inner core layer. The inner core layer also includes a central absorbent region and an outer absorbent region substantially surrounding the central absorbent region, wherein the central absorbent region has a first basis weight and the outer absorbent region has a second basis weight, wherein the first basis weight is greater than the second basis weight. The upper nonwoven layer includes a central region, an outer region surrounding the central region, and a transition region between the central region and the outer region. Multiple cellulose fibers of the inner core layer penetrate the lower surface of the upper nonwoven layer in the transition region. Attached Figure Description

[0010] Figure 1 This is a perspective view of an absorbent article according to one or more configurations shown and described herein;

[0011] Figure 2 yes Figure 1 A plan view of the absorbent article, with the surface facing the wearer facing the observer, in which a portion of the structure is cut off to more clearly show the construction of the absorbent core structure;

[0012] Figure 3 It is a section taken along line 3-3. Figure 2 A cross-sectional view, in which the top and bottom sheets are removed to show the absorber core structure more clearly;

[0013] Figure 4 It is a plan view of an example absorbent article according to one or more configurations shown and described herein, with the wearer-facing surface facing the observer, illustrating the configuration of a central absorbent area and an outer absorbent area;

[0014] Figure 5 This is a close-up illustration of the structural bonding portion according to one or more configurations shown and described herein;

[0015] Figure 6 yes Figure 5 A cross-sectional view of the structural bonding area;

[0016] Figure 7A It is taken along line 7A-7A based on one or more configurations shown and described in this article. Figure 4A cross-sectional view of an absorbent article, illustrating the outline of the inner core layer in the middle region of the absorbent article.

[0017] Figure 7A1 This is a cross-sectional view of an absorbent article according to one or more configurations shown and described herein, illustrating details of the transition region;

[0018] Figure 7B It is taken along line 7B-7B based on one or more configurations shown and described in this article. Figure 4 A cross-sectional view of an absorbent article, illustrating the outline of the inner core layer in the rear region of the absorbent article.

[0019] Figure 8 It is taken along line 8-8 based on one or more configurations shown and described in this article. Figure 4 A cross-sectional view of the absorbent article, illustrating the outline of the inner core layer;

[0020] Figure 9 This is a plan view of an example absorbent article according to one or more configurations shown and described herein, with the wearer-facing surface facing the observer, illustrating the flexural bonding channel region;

[0021] Figure 10 It is based on one or more configurations shown and described herein. Figure 9 The sectional view of the absorbent article taken by line 10-10 illustrates the outline of the inner core layer in the middle region of the absorbent article.

[0022] Figure 10A This is a cross-sectional view of an absorbent article according to one or more configurations shown and described herein, illustrating details of the transition region;

[0023] Figure 11 It is taken along line 11-11 based on one or more configurations shown and described in this article. Figure 9 A cross-sectional view of the absorbent article, illustrating the outline of the inner core layer;

[0024] Figure 12 This is a schematic diagram of an exemplary manufacturing process for forming an absorber core structure according to one or more configurations shown and described herein;

[0025] Figure 13 This is a scanning electron microscope (SEM) image of a cross-sectional view of the interface between the upper nonwoven layer and the inner core layer in the absorber core structure.

[0026] Figure 14 yes Figure 13 A magnified view of the SEM image.

[0027] Figures 15A-15C It is a test method setup for the dry CD ultra-sensitive 3-point bending method.

[0028] Figures 16A-16B This is the test method setup for the circular bending method. Figure 16B This is a top view of the platform used in this method. Detailed Implementation

[0029] As used herein, “disposable absorbent articles” or “absorbent articles” should be used in reference to articles such as diapers, training pants, diaper pants, re-fastening pants, adult incontinence pads, adult incontinence pants, feminine hygiene pads, cleaning pads, etc., each of which is intended to be discarded after use.

[0030] As used herein, "absorbent core structure" should be used with reference to the upper nonwoven layer, the lower nonwoven layer, and the inner core layer disposed between the upper and lower nonwoven layers. As used herein, "absorbent core structure" does not include any second top sheet, top sheet, second bottom sheet, or bottom sheet of the absorbent article.

[0031] As used herein, "hydrophilic" and "hydrophobic" have the widely accepted meanings in the art regarding the water contact angle on a material surface. Therefore, a material having a water contact angle greater than about 90 degrees is considered hydrophobic, and a material having a water contact angle less than about 90 degrees is considered hydrophilic. Hydrophobic compositions will increase the water contact angle on a material surface, while hydrophilic compositions will decrease the water contact angle on a material surface. Although described above, references to relative hydrophobicity or hydrophilicity between materials and compositions, between two materials, and / or between two compositions do not imply that the material or composition is hydrophobic or hydrophilic. For example, a composition may be more hydrophobic than a material. In this case, neither the composition nor the material may be hydrophobic; however, the contact angle exhibited by the composition may be greater than that of the material. Similarly, a composition may be more hydrophilic than a material. In this case, neither the composition nor the material may be hydrophilic; however, the contact angle exhibited by the composition may be smaller than that exhibited by the material.

[0032] As used herein, the term "filament" refers to any type of continuous yarn produced by processes such as spinning, meltblowing, melt fibrillation or film fibrillation, electrospinning, or any other suitable process for producing filaments. The term "continuous" in the context of filaments differs from short-length fibers in that short-length fibers are cut to a specific target length. In contrast, "continuous filaments" are not cut to predetermined lengths; instead, they can break into random lengths, but are typically much longer than short-length fibers.

[0033] As used in this article, "longitudinal" refers to the direction in which the fiber web flows through the absorbent material to change the processing direction. For the sake of brevity, "longitudinal" can be referred to as "MD".

[0034] As used in this article, "horizontal" refers to the direction perpendicular to the MD. For the sake of brevity, "horizontal" can be referred to as "CD".

[0035] "Decitex" is a measure used in the textile industry to measure yarn or filament. 1 decitex = 1 gram per 10,000 meters. In other words, if 10,000 linear meters of yarn or filament weighs 500 grams, then the yarn or filament will have 500 decitex.

[0036] As used herein, "elastic" means a material that tends to retain its shape in both dry and wet conditions and tends to return to its original shape before compression when subjected to compressive forces and upon removal of such forces. In some respects, the upper and / or lower nonwoven layers described herein may be elastic.

[0037] As used herein, “wear-facing” (sometimes referred to herein as “body-facing”) and “outward-facing” (sometimes referred to herein as “clothing-facing”) refer to the relative position of an element or the relative position of the surface of an element or group of elements, respectively. “Wear-facing” means that during wear, an element or surface is closer to the wearer than some other elements or surfaces. “Outward-facing” means that during wear, an element or surface is further away from the wearer than some other elements or surfaces (i.e., the element or surface is closer to the wearer’s clothing, which may be worn over an absorbent article).

[0038] It should be understood that each maximum numerical limit given throughout this specification includes each lower numerical limit, as such lower numerical limits are explicitly stated herein. Each minimum numerical limit given throughout this specification will include each higher numerical limit, as such higher numerical limits are explicitly stated herein. Each numerical range given throughout this specification will include each narrower numerical range falling within such a wider numerical range, as all such narrower numerical ranges are explicitly stated herein.

[0039] This disclosure relates to a disposable absorbent article comprising a top sheet, a bottom sheet, and an absorbent core structure, the absorbent core structure comprising an upper nonwoven layer and a lower nonwoven layer, wherein an inner core layer comprises a liquid absorbent material disposed between the upper and lower nonwoven layers. The liquid absorbent material may comprise a matrix comprising cellulose fibers and superabsorbent particles, sometimes referred to herein as “fluff / AGM”. The inner core layer may be contained within the nonwoven layers by substantially sealing at least the left and right sides of the upper and lower nonwoven layers at peripheral seals.

[0040] The absorbent core structure described herein is constructed to compress and recover its original shape (both wet and dry) under a series of body movements and compressions. The flexibility and / or elasticity of the absorbent core structure allow the absorbent article to comfortably conform to the wearer's anatomical geometry while effectively managing fluid as it leaves the body. This is unexpectedly achieved without typical densification hardening (for wet integrity) by utilizing elastic upper and lower nonwoven layers composed of elastic polymers above and below a loosely stacked liquid absorbent material located in the inner core layer. Surprisingly, when the absorbent core structure becomes wet, it is able to withstand structural loads and recover its shape without physically hardening or losing desired structural properties. Without being theoretically limited, it is believed that wet integrity / shape stability in cellulose-rich absorbent core structures can be achieved without significant densification and hardening when the selected elastic upper and lower nonwoven layers are positioned above and below the liquid absorbent material in the inner core layer and bonded to and around the liquid absorbent material. Both the upper and lower nonwoven fabrics may possess sufficient restoring energy to bring the liquid absorbent material back to its original or stable fibrous orientation state after compression. Encasing or encapsulating a cellulose-rich core with a simple cellulose structure or a less elastic nonwoven material may not exhibit sufficient restoring energy to recover its shape during use, particularly when wet. The structural wet-elastic nonwovens detailed herein exhibit sufficient restoring energy to recover the cellulose-rich fibrous matrix after compression and are chosen to deliver high compression recovery with relatively low stiffness in both dry and wet states. It is believed that a suitable absorbent core structure has low compressive force (low resistance) and is able to recover its shape when the user compresses and releases the compressive force in a cyclical manner with various body movements. To achieve this, the structure should maintain sufficient restoring energy after multiple cycles of compression. Without sufficient restoring energy, the structure remains in a compressed, lumped state without sufficient force (stored energy) to recover.

[0041] The absorbent article described herein also includes a shaped inner core layer comprising a central absorbent region and an outer absorbent region substantially surrounding the central absorbent region. The central absorbent region has a greater weight than the outer absorbent region, thereby creating a raised three-dimensional (3D) structure in the central region of the absorbent article. As described below, the shape of the inner core layer allows the central absorbent region to conform closely and gently conform to the upper space between the labia majora. Both the central and outer absorbent regions are highly compressible without feeling bulky, thus allowing for a close fit to a wide range of intimate body shapes without discomfort.

[0042] Producing low-density flexible absorbent core structures with a 3D-shaped inner core, as described herein, during high-speed manufacturing processes is challenging. Historically, longitudinally irregular absorbent core structures have typically been formed by wrapping liquid absorbent material within a simple cellulose liner or thin nonwoven layer. However, wrapping such structures can compress the intended 3D shape and / or leave gaps between the liquid absorbent material and the core wrapper (especially in regions where the basis weight transitions from high to low), which can negatively impact performance and fit. Forming the liquid absorbent material directly onto the upper nonwoven layer during processing is also challenging because if the nonwoven material's stretching and bending properties are insufficient, the upper nonwoven material may not fully conform to the core pocket shape in the molded drum in each of the longitudinal, transverse, and z-directions. Therefore, inner core and / or absorbent core structures with a less pronounced 3D shape can be produced without the expected thickness increase designed for fit within the space between the labia majora.

[0043] Surprisingly, it was found that by feeding an upper nonwoven layer into a molding station comprising a molding drum with a series of 3D core pockets, a low-density, flexible absorbent core structure with an irregularly shaped and formed inner core layer can be formed. As described in more detail below, the upper nonwoven layer can be drawn into the 3D core pockets of the molding drum via a vacuum below the core pockets. As the drum rotates, a stream of liquid absorbent material can be brought into the molding station and deposited into the core pockets via chute. The vacuum draws the liquid absorbent material into the core pockets and onto the upper nonwoven layer to form an irregularly shaped and formed inner core layer. Surprisingly, it was found that when the upper nonwoven layer material has a circular curvature of about 2.5 gf to about 10 gf, the upper nonwoven layer is more likely to conform to the shape of each wall of the core pocket of the molding drum. Thus, absorbent core structures can be produced in which the upper nonwoven layer is in direct contact with and conforms to the contours and shapes of the central and outer absorbent areas of the inner core layer. It was also found that the air permeability is greater than about 100 mm. 3 / mm 2 The upper nonwoven layer material at a rate of / min allows sufficient airflow under vacuum to properly guide the liquid absorbent material into the 3D core pocket of the forming drum, thereby producing an inner core layer with the desired shape and thickness profile.

[0044] Figure 1 The exemplary absorbent article 20 of this disclosure is shown in the figure. For the purpose of providing a frame of reference for this discussion, Figure 1 The absorbent article 20 is shown having a longitudinal axis 80, a transverse axis 90, and a z-direction axis 95 perpendicular to the longitudinal axis 80 and the transverse axis 90. Figure 2 yes Figure 1A plan view of the absorbent article 20, with the surface facing the wearer facing the observer, wherein a portion of the structure is cut off to more clearly show the construction of the absorbent core structure 10. Figure 3 It is along Figure 2 The sectional view taken by line 3-3 shows the top sheet 110 and bottom sheet 130 removed to show the absorber core structure 10 more clearly.

[0045] See Figures 1-3 The absorbent article 20 includes a top sheet 110, a bottom sheet 130, and an absorbent core structure 10 disposed between the top sheet 110 and the bottom sheet 130. The absorbent article 20 and the absorbent core structure 10 each include a front region 21, a rear region 23, and an intermediate region 22 disposed between the front region 21 and the rear region 23.

[0046] The absorbent core structure 10 may include an upper nonwoven layer 210 and a lower nonwoven layer 220 (also collectively referred to herein as upper nonwoven layer and lower nonwoven layer or upper nonwoven fabric and lower nonwoven fabric) and an inner core layer 200 disposed between the upper nonwoven layer 210 and the lower nonwoven layer 220. The upper nonwoven layer 210 has an upper surface 211 and a lower surface 212. The upper surface 211 may be the surface of the upper nonwoven layer 210 facing the garment, and the lower surface 212 may be the surface of the upper nonwoven layer 210 facing the wearer. The lower surface 212 of the upper nonwoven layer 210 is in direct contact with the inner core layer 200 and follows the shape of the inner core layer. In some configurations, there is essentially no gap or void between the lower surface 212 of the upper nonwoven layer and the inner core layer 200. In some configurations, at least about 60%, 70%, 80%, 85%, 90%, 95%, or even about 100% of the lower surface 212 of the upper nonwoven layer 210 is in direct contact with the inner core layer 200. The upper nonwoven layer 210 also includes a central region 502, an outer region 510 surrounding the central region 502, and a transition region 504 disposed between the central region 502 and the outer region 510. The inner core layer 200 may contain a liquid absorbent material 201, such as, for example, cellulose fibers and superabsorbent particles. In some configurations, the liquid absorbent material 201 may be uniformly distributed. In some configurations, the liquid absorbent material 201 may be discontinuously present within the absorbent core structure 10, for example, in the form of separate pockets or strips of liquid absorbent material separated from each other by areas without material.

[0047] In some configurations, the absorbent core structure 10 may have a non-rectangular perimeter. Specifically, the absorbent core 10 may be shaped to define a cone shape along its width toward the central region of the absorbent core structure. The absorbent core structure may be adapted to the geometry of the wearer's inner thigh, such as, for example, an hourglass shape, an offset hourglass shape (one end is wider than the opposite end and has a narrowing middle section between the two ends), a bicycle seat shape (one end and the central portion are narrower than the second end), an ellipse, or a trapezoid.

[0048] The inner core layer 200 may include a central absorbent region 306 extending from a front region 21 to a rear region 23 in the longitudinal direction of the absorbent article, and an outer absorbent region 325 substantially surrounding the central absorbent region 306. The central absorbent region 306 may include a transition region 330 extending around the periphery of the central absorbent region 306, in which the basis weight of the inner core layer 200 gradually decreases. The inner core layer 200 may be irregularly shaped in both the longitudinal and transverse directions, such that the basis weight of the inner core layer is greater in the central absorbent region 306 than in the outer absorbent region 325. In some configurations, the central region 502 of the upper nonwoven layer 210 is in direct contact with and follows the shape of the upper surface of the central absorbent region 306, the transition region 504 of the upper nonwoven layer 210 is in direct contact with the transition region 330 and follows the shape and angle of the transition region, and / or the outer region 510 of the upper nonwoven layer is in direct contact with and follows the shape of the outer absorbent region 325.

[0049] The absorbent article 20 may include the following structure (from the wearer-facing surface to the outward-facing surface): a top sheet 110, an upper nonwoven layer 210, an inner core layer 200, a lower nonwoven layer 220, and a back sheet 130. In some aspects, the top sheet 110 may be in direct contact with the upper nonwoven layer 210, the upper nonwoven layer 210 may be in direct contact with the inner core layer 200, and / or the inner core layer 200 may be in direct contact with the lower nonwoven layer 220. As used herein, "direct contact" means that there is no additional intermediate component layer between the respective layers in direct contact. However, it is not excluded that an adhesive material may be disposed between at least a portion of the aforementioned layers.

[0050] The upper nonwoven layer 210 may include a left region 210a and a right region 210b, and the lower nonwoven layer 220 may include a left region 220a and a right region 220b. The upper and lower nonwoven layers 210 and 220 may extend outward from the inner core periphery 200a and may be bonded together using adhesive or other conventional bonding methods to form a peripheral seal 230, including but not limited to ultrasonic bonding, fusion bonding, crimping, and combinations thereof. In some configurations, the entire inner core 200 may be located inside the peripheral seal 230. The peripheral seal 230 may help seal the liquid-absorbing material of the inner core 200 within the upper and lower nonwoven layers 210 and 220. The peripheral seal 230 may include at least a first lateral sealing region 231 and a second lateral sealing region 231'. In some configurations, the peripheral seal 230 may also include a front peripheral sealing region 232 and / or a rear peripheral sealing region 233. In some configurations, the peripheral seal 230 may extend around the entire inner core periphery 200a. In some configurations, the peripheral seal 230 may extend partially around the inner core periphery 200a.

[0051] In some configurations, the inner core layer 200 can be contained within the upper nonwoven layer 210 and the lower nonwoven layer 220 by substantially sealing at least a portion of the left-side regions 210a, 220a and the right-side regions 210b, 220b of the upper nonwoven layer 210 and the lower nonwoven layer 220. In some configurations, the inner core layer 200 can be contained within the upper nonwoven layer 210 and the lower nonwoven layer 220 by sealing at least a portion of the left-side regions 210a, 220a and the right-side regions 210b, 220b of the upper nonwoven layer 210 and the lower nonwoven layer 220. Unrestricted by theory, it is believed that when attached to the inner core layer by applying a core-construction adhesive, the elastic nonwoven layer containing polymer fibers can maintain its shape and resist plasticization upon wetting. This core-construction adhesive is applied directly to the inner core layer or via conventional spray application, chosen to achieve bonding without interrupting fluid flow to the inner core layer. A peripheral seal 230 may be positioned in at least a central region 22 of the absorbent article 20 and / or absorbent core structure 10. The central region 22 (located between the wearer's thighs during use) is believed to be subjected to the most frequent and / or greatest forces during use. It has been found that the presence of at least partial peripheral seals in the left and right regions of the upper and lower nonwoven layers outside the inner core layer can help ensure that the upper and lower nonwoven layers maintain their structural function without separation during physical deformation, thereby limiting any potential integrity and gathering problems. In addition, the peripheral seals allow any excess nonwoven material to be removed so that the absorbent core structure can be shaped to conform to the geometry of the inner thigh.

[0052] The peripheral seal 230 may have a seal width WS between about 1 mm and about 10 mm, or between about 2 mm and about 8 mm, or between about 3 mm and 6 mm. The seal width WS may be uniform or may vary around the periphery of the inner core layer. In some configurations, the absorbent article 20 may also include a front seal 234 positioned in the front region 21 of the absorbent article and a rear seal 235 positioned in the rear region 23 of the absorbent article. The front seal 234 and / or the rear seal 235 may seal the top sheet, the upper nonwoven layer, the lower nonwoven layer, and the bottom sheet together. In some configurations, the front seal 234 and / or the rear seal 235 may seal the top sheet and the bottom sheet. In some configurations, the front seal 234 and / or the rear seal 235 may be a coiled seal.

[0053] In some configurations, the upper nonwoven layer 210 and the lower nonwoven layer 220 may be discrete materials that can be cut to approximately the size and shape of the inner core layer 200 for fitting between the top sheet 110 and the bottom sheet 130, but may not substantially extend into the front seal 234 or the rear seal 235. In some configurations, the inner core layer 200, the upper nonwoven layer 210, and / or the lower nonwoven layer 220 may be shaped, meaning they are non-rectangular. In some configurations, the upper nonwoven layer 210 and / or the lower nonwoven layer 220 may extend from the front edge of the absorbent article, through the front seal 234 and the rear seal 235, to the rear edge of the absorbent article.

[0054] like Figure 2 As shown, the absorbent article 20 may also include a base structure 100, which includes an absorbent core structure 10. The absorbent core structure 10 and / or the inner core layer 200 may be shaped. The sides 120 and 125 of the absorbent article 20 may follow the general outline of the absorbent core structure 10 and / or the inner core layer 200. Thus, for example, in the case where the absorbent core structure 10 has an hourglass shape, the sides 120, 125 of the absorbent article 20 may also be arranged in an hourglass shape. However, it is contemplated that the sides 120 and 125 are generally straight or slightly curved such that they do not follow the outline of the absorbent core structure. In some configurations, the absorbent article 20 may be symmetrical or asymmetrical about the longitudinal centerline 80. Similarly, the absorbent article 20 may be symmetrical or asymmetrical about the transverse centerline 90.

[0055] As previously mentioned, the absorbent article 20 may include an inner core layer 200 having an irregular distribution of liquid absorbent material in the longitudinal and transverse directions. Figure 4This is a plan view of the absorbent article 20, illustrating the dimensional and shape characteristics of the inner core layer 200. The inner core layer 200 may include a central absorbent region 306 having a first basis weight and an outer absorbent region 325 having a second basis weight. The outer absorbent region 325 substantially surrounds the central absorbent region 306. The first basis weight of the central absorbent region 306 may be greater than the second basis weight of the outer absorbent region 325. In some configurations, the first basis weight and the second basis weight may differ by about 20% to about 100%. The first basis weight may be about 220 gsm to about 450 gsm, or about 300 gsm to about 425 gsm, as measured according to the inner core layer basis weight method. The second basis weight may be about 150 gsm to about 320 gsm, or about 200 gsm to about 300 gsm, as measured according to the inner core layer basis weight method.

[0056] It should be understood that the increase in basis weight in the central absorbent region 306 is due to an increase in the liquid absorbent material in the inner core layer 200 located in the central absorbent region 306 relative to the outer absorbent region 325. The inner core layer 200 described herein can be a monolithic structure. As used herein, "monolithic structure" means that the inner core layer 200 is continuous and substantially composed of one type of material, which is substantially the same material, or a substantially identical combination of two or more materials throughout the inner core layer 200. Variations in the density and concentration of the materials may occur, but these variations are limited to those that can be obtained without incorporating regions that are individually formed and then physically bonded together. For example, when the inner core layer 200 contains liquid absorbent material (e.g., cellulose fibers and superabsorbent polymers), the relative concentrations of superabsorbent particles and cellulose fibers may differ in different portions of the inner core layer 200. However, when the construction is monolithic, the inner core layer 200, for example, does not include layers or laminates of different compositions. Similarly, variations in density or concentration of various components may occur in the longitudinal, transverse, or thickness directions of the inner core layer 200, but the inner core layer 200 should not include regions or layers of different compositions that are formed separately and subsequently bonded together, or regions of the same or different materials that are physically separated by regions that are substantially free of liquid-absorbing material matrix weight.

[0057] The absorbent article 20 may have an average density measured in the central absorbent region 306 and the outer absorbent region 325, which may be about 0.045 g / cm³. 3 To approximately 0.150 g / cm 3The average density of the absorbent article, as measured by methods based on the thickness, basis weight, and density of the absorbent article, may be substantially similar in some configurations when measured in the central absorbent region 306 and the outer absorbent region 325. In some configurations, the average density of the absorbent article measured in the outer absorbent region 325 may be within approximately 0% to approximately 20%, or approximately 0% to approximately 18%, or approximately 0% to approximately 10%, or approximately 0% to approximately 5% of the average density measured in the central absorbent region.

[0058] The absorbent article 20 may have a varying thickness in both the longitudinal and transverse directions (e.g., it may be shaped to have a higher thickness at the center). In some configurations, the absorbent article 20 may have a first thickness measured in the central absorbent region 306 and a second thickness measured in the outer absorbent region 325. In some configurations, the first thickness may be from about 2.5 mm to about 6 mm, and the second thickness may be from about 1.0 mm to about 3.0 mm, as measured according to the absorbent article thickness, basis weight, and density method. In some configurations, the ratio of the first thickness to the second thickness may be from about 1.2 to about 2.5. In some configurations, the absorbent article may have a thickness increase of at least 20%, or from about 20% to about 100%, or from about 25% to about 80%, or from about 30% to about 60%. As used herein, "thickness increase" refers to the percentage increase of the first thickness relative to the second thickness.

[0059] The inner core layer 200 may have a non-rectangular perimeter. Specifically, the inner core layer 200 may be shaped such that the liquid-absorbing material 201 in the central absorption region 306 can define a cone shape along its width toward the central region, thereby creating a 3D shape that can better fit within and between the upper space between the labia majora, and fit at the perineum and the base of the mons pubis. Figure 4 As shown, the central absorbent area 306 can be shaped, meaning it is non-rectangular. The central absorbent area 306 can be shaped to gently lie between and inside the external gaps between the labia majora, while gently contacting the blood-flowing external portion of the labia minora (without entering the interior between the labia minora). Suitable shapes for the central absorbent area 306 include, but are not limited to, hourglass shape, offset hourglass shape (one end is wider than the opposite end and has a narrowing middle section between the two ends), or bicycle seat shape (one end and the central portion are narrower than the second end).

[0060] In some configurations, the central absorption region 306 may define a periphery including a pair of inwardly recessed longitudinal sides 308a, 308b, an outwardly projecting front edge 310, and an outwardly projecting rear edge 312. The central absorption region 306 may include a front region 314 having a first lateral width W1, a rear region 318 having a third lateral width W3, and an intermediate region 316 positioned therebetween having a second lateral width W2. In some configurations, the second lateral width W2 may be less than the first lateral width W1 and / or the third lateral width W3. In some configurations, the third lateral width W3 may be greater than the first lateral width W1 and the second lateral width W2. The first lateral width W1 may be from about 20 mm to about 35 mm, or from about 22 mm to about 30 mm, as measured in the front region 314 from the outermost point of the first inwardly recessed longitudinal side to the outermost point of the second inwardly recessed longitudinal side. The second lateral width W2 is approximately 10 mm to approximately 20 mm, or approximately 12 mm to approximately 15 mm, as measured in the intermediate region 316 from the innermost point of the first inwardly recessed longitudinal side to the innermost point of the second inwardly recessed longitudinal side. The third lateral width W3 can be approximately 30 mm to approximately 45 mm, or approximately 32 mm to approximately 40 mm, as measured in the rear region 318 from the outermost point of the first inwardly recessed longitudinal side to the outermost point of the second inwardly recessed longitudinal side. In some configurations, the second lateral width W2 is approximately 20% to approximately 40% of the minimum lateral width of the inner core layer.

[0061] In some configurations, the central absorber region 306 may have a longitudinal length LC of about 115 mm to about 200 mm, or about 125 mm to about 195 mm, as measured from the outermost point of the outwardly projecting front edge 310 to the outermost point of the outwardly projecting rear edge 312. In some configurations, the central absorber region 306 may have a longitudinal length LC of about 50% to about 75% of the longitudinal length LT of the inner core layer.

[0062] Unrestricted by theory, it is believed that the shape of the central absorbent area allows it to more effectively capture fluid flowing from the labia minora within the labia majora, regardless of the variety of female genital shapes and sizes. It is believed that, for effective conformation and gentle adaptation within and between the upper spaces of the labia majora, the central absorbent area should be relatively narrow, for example, with a lateral width in the range of 10 mm to 20 mm, and the narrow portion should have a correspondingly narrowing length, for example, approximately 50 mm to 80 mm. Furthermore, the central absorbent area should have a generally concave shape, allowing close contact with the body to prevent fluid from spreading laterally, but should also be wider in both the anterior and posterior regions to gently conform to the perineum and the base of the mons pubis, where the body's natural concavity may allow fluid to bypass the pad and spread across the body.

[0063] In some configurations, the outwardly projecting front edge 310 of the central absorption region 306 may be positioned at a distance of approximately 25 mm to approximately 45 mm from the front edge 424 of the inner core layer 200. In some configurations, the outwardly projecting rear edge 312 of the central absorption region 306 may be positioned at a distance of approximately 25 mm to approximately 85 mm from the rear edge 426 of the inner core layer 200.

[0064] It can also be described that the shape of the central absorbent region 306 can taper as it extends from the front region to the middle region of the absorbent article, thereby defining a narrow portion 350 between the inwardly recessed longitudinal sides. The narrow portion 350 of the central absorbent region can have a width at its narrowest point, which is located in front of or shares a side with the transverse centerline 91 of the first wing 140 and the second wing 150. The narrow portion 350 of the central absorbent region 306 can be located in the middle region 22 of the absorbent article 20. In some configurations, the absorbent core structure 10 and / or the inner core layer 200 can be shaped to substantially conform to the shape of the central absorbent region 306. In some configurations, the absorbent core structure 10 can have a width at its narrowest point, which is located in front of or shares a side with the centerline 91 of the first wing 140 and the second wing 150.

[0065] Figure 7A yes Figure 4 The cross-sectional view of the absorbent article 20 taken along line 7A-7A illustrates the size and shape characteristics of the inner core layer 200 in the middle region 22 of the absorbent article 20. Figure 7A1 This is a cross-sectional view of the absorbent article 20, which illustrates the details of the transition zone 330. Figure 7B yes Figure 4 The cross-sectional view of the absorbent article 20 taken along line 7B-7B illustrates the size and shape characteristics of the inner core layer 200 in the rear region 23 of the absorbent article. Figure 8 yes Figure 4 The absorbent article 20 is a cross-sectional view taken along line 8-8, which illustrates the size and shape characteristics of the inner core layer 200.

[0066] like Figures 7A-8 As shown, the absorbent article 20 can have varying thicknesses in both the longitudinal and transverse directions. The width of the central absorbent region 306 can vary along the longitudinal axis, such that the width of the central absorbent region 306 in the rear region 23 is greater than its width in the middle region 22. In some configurations, the transverse width of the narrowest portion of the central absorbent region can be approximately 20% to approximately 40% of the minimum transverse width WC of the inner core layer.

[0067] As previously mentioned, the central absorber region 306 may include a transition region 330 in which the basis weight of the inner core gradually decreases. Figure 7A1As shown, the transition zone 330 can have a width (TZ) of approximately 1 mm to approximately 5 mm. The width of the transition zone can be measured from images obtained by micro-CT and analyzed through image analysis. Without being theoretically limited, it is believed that a transition zone 330 with the aforementioned width can help produce the desired 3D shape of the central absorption zone and / or inner core layer. It is believed that if the transition zone is wider than approximately 5 mm, the central absorption zone may not fit snugly within and between the upper space of the labia majora.

[0068] In some configurations, the central absorption region 306 may include a transition region 330 that forms an angle A relative to the z-axis 95 of approximately 2 degrees to approximately 40 degrees, or approximately 5 degrees to approximately 35 degrees, or approximately 15 degrees to approximately 30 degrees. The angle A of the transition region can be measured from images obtained by micro-CT and analyzed through image analysis. In some configurations, the upper nonwoven layer 210 may form an angle in the transition region 504 relative to the z-axis 95, which substantially follows the angle A of the transition region 330 of the inner core layer 200. The upper nonwoven layer 210 may form an angle in the transition region 504 relative to the z-axis 95 of approximately 2 degrees to approximately 40 degrees, or approximately 5 degrees to approximately 35 degrees, or approximately 15 degrees to approximately 30 degrees.

[0069] Although the central absorber region 306, outer absorber region 325, and transition region 330 have been discussed with reference to the inner core layer 200, the descriptions of the different regions can also be applied to the absorbent article 20. The basis weight of the absorbent article in the central absorber region can be from about 300 gsm to about 500 gsm, as measured by the absorbent article thickness, basis weight, and density method. The basis weight of the absorbent article in the outer absorber region can be from about 200 gsm to about 400 gsm, as measured by the absorbent article thickness, basis weight, and density method.

[0070] In some configurations, such as Figure 4 As shown, the absorbent article 20 may also include multiple structural bonding sites 15. Figure 5 and Figure 6 An example of the bonding portion 15 of the example structure is shown. Figure 5 This is a close-up illustration of the bonding portion 15 of the example structure. Figure 6 yes Figure 5 A cross-sectional view of the structural bonding portion 15. The structural bonding portion 15 can be symmetrical and / or asymmetrical, and can be of any shape, including but not limited to circular, elliptical, heart-shaped, rhomboid, triangular, square, star-shaped, and / or X-shaped. While the shape of the structural bonding portion can be any shape, suitable shapes can be more detailed, such as asymmetrical shapes (as opposed to simple points). The structural bonding portion 15 can be on the absorbent article and / or on the absorbent core structure. In some configurations, the structural bonding portion can have approximately 2 mm. 2 Approximately 5mm2 The total structural bond area may be from about 0.5% to about 5%, or about 0.75% to about 4.5%, or about 1% to about 4% of the absorbent core structure, as measured by methods for measuring the pattern spacing and area of ​​the structural bonded areas. In some configurations, the total structural bond area may be from about 1% to about 4% of the absorbent article, as measured by methods for measuring the pattern spacing and area of ​​the structural bonded areas. The average distance between structural bonded areas may be from about 10 mm to about 32 mm. In some configurations, the average distance between structural bonded areas may be greater than about 20 mm. In some configurations, the structural bonded areas may have a maximum width of from about 1 mm to about 6 mm, or from about 1.5 mm to about 5 mm, or from about 2 mm to about 4 mm. Without being theoretically limited, it is believed that the average distance between structural bonded areas and / or the size of the structural bonded areas can help maintain the structural integrity of the absorbent core structure without producing undesirable stiffness that could inhibit the absorbent article's ability to conform to the body.

[0071] In some configurations, structural bonding sites may be distributed across the absorbent article and / or absorbent core structure, or they may be clustered within regions of the absorbent article and / or absorbent core structure. In some configurations, structural bonding sites may be clustered in the intermediate region 22 of the absorbent article 20 and / or absorbent core structure 10. In some configurations, the intermediate region 22 of the absorbent article 20 and / or absorbent core structure 10 may be substantially free of structural bonding sites and may be surrounded by the area of ​​structural bonding sites and / or embossing. In some configurations, such as Figure 4 As shown, the outer absorption region 325 may include a plurality of structural bonding sites 15, and the central absorption region 306 may have substantially no structural bonding sites 15.

[0072] In some configurations, the structural bonding portion 15 may bond the top sheet 110, the upper nonwoven layer 210, the absorbent core structure 10, and the lower nonwoven layer 220. The absorbent article 20 and / or the absorbent core structure 10 may include the upper nonwoven layer 210 and the lower nonwoven layer 220, which are brought closer together in the Z-direction at the structural bonding portion 15, but are not fused together. Because these structural bonding portions are not fused together, they may not be permanent in nature, but may become entangled with the material within the structural bonding portion. In some configurations, the structural bonding portion 15 may be substantially unbonded.

[0073] like Figures 9-11As shown, the absorbent article 20 may also include one or more flexural bonding channel regions 160. The flexural bonding channel regions 160 may be continuous recesses and / or a series of individually compressed, closely spaced embossings. Figure 9 This is a plan view of an example absorbent article, with the wearer-facing surface facing the observer, illustrating the flexural bonding channel region 160. Figure 10 yes Figure 9 The sectional view of the absorbent article 20 taken along line 10-10 illustrates the size and shape characteristics of the flexural bonding channel region 160 and the inner core layer 200 in the intermediate region 22 of the absorbent article. Figure 10A This is a cross-sectional view of the absorbent article 20, which illustrates the details of the transition zone 330. Figure 11 yes Figure 9 The absorbent article 20 is a cross-sectional view taken along line 11-11, which illustrates the flexural bonding channel region 160 and the size and shape of the inner core layer.

[0074] In some configurations, at least one flexural bonding channel region 160 may be located between the central absorbent region 306 and the outer absorbent region 325. The flexural bonding channel region 160 may be located in the transition region 330 or in the outer absorbent region 325. In some configurations, the flexural bonding channel region 160 may be located near the transition region 330 in the outer absorbent region 325. In some configurations, the flexural bonding channel region 160 may be located about 1 mm to about 10 mm, or about 3 mm to about 6 mm, outside the outermost edge of the transition region 330. In some configurations, the flexural bonding channel region 160 may be located in at least the intermediate region 22 of the absorbent article and may substantially surround the central absorbent region 306. Figure 10A As shown, the central absorption region 306 may include a transition region 330, which forms an angle A' of approximately 2 degrees to approximately 40 degrees, or approximately 5 degrees to approximately 35 degrees, or approximately 15 degrees to approximately 30 degrees relative to the z-axis 95. The angle A' of the transition region can be measured from images obtained by micro-CT and analyzed through image analysis.

[0075] Figure 12An exemplary manufacturing process 900 for forming an absorbent core structure is shown, wherein a liquid absorbent material 201 (e.g., cellulose and superabsorbent polymer) is deposited onto an upper nonwoven layer 210 advancing in the process. Process 900 can utilize various mechanisms and a variety of web handling devices, including but not limited to a forming drum 925, a liquid absorbent material deposition chute 950, and guide rollers 902, 904, and 906. The upper nonwoven layer 210, coated with a spray adhesive, is fed into the forming drum 925. The forming drum 925 includes a series of 3D core pockets equidistantly spaced along the outer periphery of the forming drum. The upper nonwoven layer 210 is drawn into the core pockets via a vacuum positioned below the core pockets. A flow of liquid absorbent material 201 is carried by a rapidly moving airflow and deposited into the core pockets via the chute 950. The vacuum draws the liquid absorbent material into the core pockets, placing it on the upper nonwoven layer 210 to form the shape of the inner core layer 200. Upon exiting the molding drum 925, the lower nonwoven layer 220, pre-coated with spiral adhesive, combines with the upper nonwoven layer 210 and the inner core layer 200 to form a 3D absorbent core structure.

[0076] As discussed above, the shaped inner core layer described herein can be produced when the upper nonwoven layer is deformable to conform to the shape of the core pocket in the shaped drum and has sufficient permeability to allow the liquid absorbent material to be effectively and firmly deposited onto the upper nonwoven layer during manufacturing. Surprisingly, multiple cellulose fibers of the inner core layer penetrate the lower surface of the upper nonwoven layer. In some configurations, multiple cellulose fibers penetrate the lower surface 212 of the upper nonwoven layer but stop penetrating before reaching the upper surface 211 of the upper nonwoven layer. Without being bound by theory, it is believed that when a vacuum is applied during the manufacturing of the absorbent core structure, the cellulose fibers of the liquid absorbent material are drawn into the upper nonwoven layer and entangled with the polymer fibers of the upper nonwoven layer. A particularly suitable upper nonwoven layer material is porous enough that cellulose fibers (under vacuum) can be drawn into the upper nonwoven layer 210, thereby providing close contact between the upper nonwoven layer 210 and the inner core layer 200, as well as providing additional anchoring of the liquid absorbent material 201 to the upper nonwoven layer 210.

[0077] Figure 13 and Figure 14 This is a SEM image of the interface 205 between the upper nonwoven layer 210 and the inner core layer 200, which shows the close contact between the upper nonwoven layer 210 and the inner core layer 200 caused by the direct deposition of liquid absorbent material 201 onto the upper nonwoven layer 210 inside the core pocket in the molding drum under vacuum. Figure 13 This is an SEM image taken at 50x magnification. Figure 14 It was shot at 275x magnification. Figure 13 A magnified view of the SEM image. (e.g.) Figure 14As shown, individual cellulose fibers 202 of the liquid absorbent material 201 have penetrated the lower surface 212 of the upper nonwoven layer 210 and remain within the upper nonwoven layer 210. At least a portion of the plurality of cellulose fibers 202 are entangled with the polymer fibers 500 of the upper nonwoven layer 210. In some configurations, the cellulose fibers 202 of the inner core layer 200 are entangled with the polymer fibers 500 of the upper nonwoven layer such that when the upper nonwoven layer is separated from the inner core layer, some fibers of one layer remain in the opposite layer. In some configurations, the cellulose fibers 202 penetrate into the upper nonwoven layer 210 by a distance of about 0.01 mm to about 0.6 mm, or about 0.1 mm to about 0.5 mm, or about 0.2 mm to about 0.4 mm. Unrestricted by theory, it is believed that the penetration of multiple cellulose fibers 202 through the lower surface 212 of the upper nonwoven layer 210 and / or the entanglement of cellulose fibers 202 with the polymer fibers 500 of the upper nonwoven layer 210 improves the mechanical stability between the upper nonwoven layer 210 and the inner core layer 200, and helps to improve the fluid transport from the upper nonwoven layer 210 to the inner core layer 200 for storage.

[0078] In some configurations, multiple cellulose fibers 202 of the inner nonwoven layer 200 penetrate the lower surface 212 of the upper nonwoven layer 210 in the transition region 504 of the upper nonwoven layer 210, indicating close contact between the upper nonwoven layer 210 and the transition region 330 of the inner core layer 200. In some configurations, multiple cellulose fibers 202 of the inner nonwoven layer 200 penetrate the lower surface 212 of the upper nonwoven layer 210 in the central region 502 of the upper nonwoven layer 210, indicating close contact between the upper nonwoven layer 210 and the central absorption region 306.

[0079] In some configurations, the lower nonwoven layer 220 is essentially free of cellulose fibers.

[0080] A suitable upper nonwoven layer may have a basis weight of about 30 gsm to about 85 gsm, or about 35 gsm to about 70 gsm, or about 40 gsm to about 60 gsm. The upper nonwoven layer may have a tensile stiffness of about 0.1 N / mm to about 2.2 N / mm, or about 0.3 N / mm to about 1.6 N / mm, as measured by the CD cyclic elongation to 3% strain method. The upper nonwoven layer may have a fracture strain greater than about 10%, or about 10% to about 50%, or about 20% to about 40%, as measured by the fracture strain method. The upper nonwoven layer may have a permanent strain of about 0.005 mm / mm to about 0.013 mm / mm, or 0.005 mm / mm to about 0.0090 mm / mm, as measured by the CD cyclic elongation to 3% strain method. The upper nonwoven layer at 7 g / cm 2Under pressure, it can have a thickness of about 0.3 mm to about 1.3 mm, and / or at 70 g / cm³. 2 Under pressure, it can have a thickness of about 0.2 mm to about 0.7 mm, as measured by the nonwoven thickness-pressure method.

[0081] A suitable underlayer nonwoven layer can have a basis weight of about 10 gsm to about 40 gsm, or about 15 gsm to about 20 gsm. The underlayer nonwoven layer can have a tensile stiffness of about 0.2 N / mm to about 2.0 N / mm, as measured by the CD cyclic elongation to 3% strain method. The underlayer nonwoven layer can have a fracture strain greater than about 10%, or about 10% to about 50%, or about 20% to about 40%, as measured by the fracture strain method. The underlayer nonwoven layer can have a permanent strain of about 0.005 mm / mm to about 0.018 mm / mm, as measured by the CD cyclic elongation to 3% strain method. The underlayer nonwoven layer at 7 g / cm 2 Under pressure, it can have a thickness of about 0.1 mm to about 1.3 mm, as measured by the nonwoven thickness-pressure method.

[0082] The upper and lower nonwoven layers may contain polymer fibers. Suitable upper and lower nonwoven fibers may be selected from PET (polyethylene terephthalate), PP (polypropylene), BiCo (bicomponent fiber) selected from PE / PP (PE sheath and PP core) and / or PE / PET (PE sheath and PET core), PLA (polylactic acid), and combinations thereof.

[0083] Suitable upper nonwoven fabrics may contain about 60% to about 100%, or about 70% to about 100% synthetic fibers, or about 0% to about 40%, or about 0% to about 30% regenerated cellulose fibers, such as rayon and / or viscose fibers.

[0084] The upper nonwoven layer may comprise short fibers with lengths greater than about 10 mm, or greater than about 25 mm, or from about 10 mm to about 100 mm, or from about 20 mm to about 75 mm, or from about 25 mm to about 50 mm. The upper nonwoven layer may comprise fibers with diameters from about 1.3 dtex to about 10.0 dtex, alternatively from about 1.3 dtex to about 6.0 dtex, or alternatively from about 2.0 dtex to about 5.0 dtex. Without theoretical limitations, it is believed that if the fibers in the upper nonwoven layer are smaller than about 1.3 dtex, there may not be sufficient airflow through the material during manufacturing.

[0085] In some configurations, the upper nonwoven layer may comprise a blend of short fibers. When the upper nonwoven layer comprises a blend of short fibers, the fiber blend preferably comprises 30% or less of fibers with a fiber diameter of 1.3 dtex and / or 30% or less of fibers with a fiber diameter of 10.0 dtex. In some configurations, the upper nonwoven layer may comprise fibers, wherein the fibers are a blend of short fibers with an average fiber diameter of about 2.0 dtex to about 8.0 dtex. Without being theoretically limited, it is believed that fibers with an average fiber diameter of about 2.0 dtex to about 8.0 dtex will help to allow sufficient airflow through the material during the manufacture of the absorbent core structure.

[0086] The lower nonwoven layer may comprise fibers with a length greater than about 10 mm, or greater than about 25 mm, or about 10 mm to about 100 mm, or about 20 mm to about 75 mm, or about 25 mm to about 50 mm. In some configurations, the lower nonwoven layer may comprise continuous fibers. The lower nonwoven layer may comprise fibers with a fiber diameter of about 1.3 dtex to about 5.0 dtex, or about 1.3 dtex to about 3.3 dtex, or about 1.3 dtex to about 2.2 dtex, or about 2.0 dtex to about 10.0 dtex. In some configurations, the lower nonwoven layer may comprise fibers, wherein the fibers are a blend of fibers with a fiber diameter of about 0.1 dtex to about 6.0 dtex.

[0087] In some configurations, the upper nonwoven layer may comprise a blend of fibers, wherein at least a portion of the fibers have a diameter of about 2.0 dtex to about 10 dtex, and the lower nonwoven layer may comprise a blend of fibers, wherein at least a portion of the fibers have a diameter of about 1.3 dtex to about 5 dtex. In some configurations, the upper nonwoven layer may comprise a blend of fibers, wherein at least a portion of the fibers have a diameter of about 1.3 dtex to about 2.2 dtex, and the lower nonwoven layer may comprise a blend of fibers, wherein the blend of fibers has a diameter of about 1.3 dtex to about 5 dtex.

[0088] Suitable upper and lower nonwoven layer materials can bend under bending force and recover their original shape. Thin or highly flexible materials bend easily under low peak force (load) and low bending energy. Unsuitable materials, while easily bent, lack sufficient recovery energy and therefore remain deformed due to insufficient recovery energy. Suitable materials possess sufficient energy to recover their initial pre-bent state. Materials with sufficient bending recovery energy can be considered as elastic upper and lower nonwoven layers. Particularly suitable upper nonwoven layers can have a strength greater than approximately 0.03 N. mm, or approximately 0.03N mm to approximately 1N mm, or approximately 0.04N mm to approximately 0.5N The dry recovery energy is mm. A particularly suitable upper nonwoven layer can have less than about 1.6 N. mm, or less than about 1.1N mm of dry bending energy.

[0089] As described above, the upper and lower nonwoven fabrics may include polymer fibers. Polymer fibers may be included to help provide structural integrity of the upper and lower nonwoven fabrics. Polymer fibers can help improve the structural integrity of the upper and lower nonwoven fabrics in both the longitudinal (MD) and transverse (CD) directions, which can facilitate web operations during the processing of the upper and lower nonwoven fabrics to incorporate them into the pad.

[0090] Polymer fibers with any suitable composition can be selected. Some examples of suitable polymer fibers may include bicomponent fibers comprising polyethylene (PE) and polyethylene terephthalate (PET) components, or polyethylene terephthalate and co-ethylene terephthalate components. The components of the bicomponent fibers can be configured in a sheath-core configuration, a side-by-side configuration, an eccentric sheath-core configuration, a trefoil arrangement, or any other desired configuration. In some configurations, the polymer fibers may include bicomponent fibers having a PE / PET composition configured in a concentric sheath-core configuration, wherein the polyethylene component forms the sheath.

[0091] While other materials may be useful in forming elastic structures, the stiffness of the PET core component in a sheath-core fiber configuration is believed to be useful in imparting elasticity to both the upper and lower nonwoven fabrics. In synergistic combinations, the PE sheath component, having a lower melt temperature than the PET core component, can be used to provide interfiber melt / fusion bonding, achieved via heat treatment of the precursor pad. This can contribute to providing tensile strength to the web on both the MD and CD. This interfiber bonding can be used to reduce fiber-to-fiber slippage, thereby further contributing to imparting shape stability and elasticity to the material, even when the material is wetted.

[0092] With a relatively high weight fraction of polymer fibers, more connections can be created within the structure via heat treatment. However, too many connections can impart greater stiffness to the upper and lower nonwoven fabrics than desired. For this reason, selecting the weight fraction of polymer fibers may involve prioritizing and balancing the competing needs for stiffness and flexibility in the upper and lower nonwoven fabrics.

[0093] As described above, the upper and lower nonwoven fabrics may additionally include polymer fibers, which increase the elasticity of the upper and lower nonwoven fabrics. Elastic polymer fibers help the upper and lower nonwoven fabrics maintain permeability and compression recovery. In some configurations, the upper and lower nonwoven fabrics may include elastic polymer fibers with variable cross-sections (e.g., circular and hollow helical), and / or may include elastic fibers of different sizes.

[0094] The polymer fibers can be elastic and can be spun from any suitable thermoplastic resin, such as polypropylene (PP), polyethylene terephthalate (PET), or other suitable thermoplastics known in the art. The average short fiber length of the elastic polymer fibers can be selected in the range of greater than about 10 mm, about 20 mm to about 100 mm, about 30 mm to about 50 mm, or about 35 mm to about 50 mm. The elastic polymer fibers can have any suitable structure or shape. For example, the elastic polymer fibers can be circular or have other shapes, such as spiral, fan-shaped elliptical, trefoil, fan-shaped band, etc. Furthermore, the elastic polymer fibers can be solid, hollow, or multi-hollow. The elastic polymer fibers can be solid and circular in shape. In other suitable examples, the elastic polymer fibers include polyester / co-extruded polyester fibers. Other suitable examples of elastic polymer fibers can include bicomponent fibers, such as polyethylene / polypropylene, polyethylene / polyethylene terephthalate, and polypropylene / polyethylene terephthalate bicomponent fibers. These bicomponent fibers can have a sheath / core configuration.

[0095] The elastic polymer fiber can be polyethylene terephthalate (PET) fiber or other suitable non-cellulose fibers known in the art. PET fibers can be endowed with any suitable structure or shape. For example, the PET fiber can be circular or have other shapes, such as spiral, fan-shaped ellipse, trefoil, fan-shaped band, hollow spiral, etc. PET fibers can be solid, hollow, or multiple times hollow. In a specific example, the cross-section of the PET fiber can be hollow and have a curved or spiral configuration along its length. Optionally, the elastic polymer fiber can be helical or flat-curled. The elastic polymer fiber can have an average crimp count of about 4 to about 12 crimps per inch (cpi), or about 4 cpi to about 8 cpi, or about 5 cpi to about 7 cpi, or about 9 cpi to about 10 cpi. Specific, non-limiting examples of elastic polymer fibers are available from Wellman, Inc. (Ireland) under the trade names H1311 and T5974. Other examples of suitable elastic polymer fibers are disclosed in US 7,767,598.

[0096] Careful selection of reinforcing and elastic polymer fibers is essential. For example, while the constituent polymers forming the reinforcing and elastic polymer fibers may be similar, the elastic polymer fiber composition should be selected such that the melting temperature of its components is higher than that of the bondable component of the reinforcing polymer fiber. Otherwise, during heat treatment, the elastic polymer fiber may bond to the reinforcing polymer fiber, and vice versa, resulting in an overly rigid structure. To avoid this risk, the reinforcing polymer fiber may comprise a bicomponent fiber, such as a core-sheath configuration fiber with a sheath component having a relatively low melting temperature at which fusion bonding will occur, while the elastic polymer fiber may consist only of the constituent chemical composition of the core, which may be a polymer with a relatively high melting temperature.

[0097] The properties of nonwoven fabrics can be influenced by a combination of the choice of nonwoven fiber polymer, fiber characteristics, and fiber arrangement or connection method. Nonwoven fabric selection can affect the ability of an absorbent article to recover its shape after being subjected to compressive, bending, and stretching (tensile) forces during use and with body movement. If the fibers are short (less than about 10 mm), they may irreversibly rearrange under stretching and compressive forces. This rearrangement of fibers within the fiber matrix (changing their orientation / state) dissipates the stretching (elongation) or compressive forces, making the energy used to influence deformation no longer available to restore the original shape. Longer fiber networks (typically greater than about 10 mm but less than about 100 mm) can absorb typical stretching / compressive forces along the fiber length and through the structure during body movement. Therefore, the absorbed forces can be used to restore the structure to its original state. Longer fiber networks composed of finer fibers (typically less than about 15 micrometers to about 20 micrometers) are more prone to stretching and compression. Therefore, the pile / AGM structure can deform more easily (and to a greater degree), but the energy associated with these deformations is relatively small and insufficient to bring the structure back to its original state. Coarser fibers (such as those larger than about 20 micrometers or about 2.0 dtex to about 10 dtex) are flexible under physical forces, but provide enough fiber and web recovery energy to allow the structure to return to its original state.

[0098] (From a structural point of view) The fiber arrangement in a long fiber network can affect the performance of absorbent articles containing these nonwovens. Long fiber webs with coarser fibers are generally more bulky than conventional thin spunbond nonwoven webs, which consist of continuous fine fibers that are closely spaced, physically bonded together, and typically have low air permeability, resulting in reduced airflow in the forming drum. Webs that produce coarser fibers arranged in a more random orientation (such as those that can be achieved through carding, hydroentangling, and needle punching) are able to stretch and compress, whereby the fibers only temporarily adjust their arrangement (for which there are spaces between the fibers) and are able to bear / store deformation forces, and thus this energy can be used to restore the structural shape while still maintaining high air permeability.

[0099] Additionally, the finer (less than about 2.0 dtex) synthetic fibers (such as BiCo and PP fibers) typically found in spunbonds are closely spaced, relatively parallel, and tightly bonded together. The bonding fibers within these spunbond webs are so interconnected (with closely spaced point bonds) that, during stretching (elongation), the fibers at the polymer level are forced to stretch, resulting in a permanent rearrangement of the polymer chains within the fibers, and thus the fibers themselves potentially remain permanently elongated (permanently strained) and can no longer return to their initial state.

[0100] A particularly suitable upper nonwoven layer can have a circular curvature of about 2.5 gf to about 10 gf, as measured by the circular curvature method. Without being theoretically limited, it is believed that upper nonwoven layer materials with a circular curvature greater than about 10 g may be too stiff to fully conform to the 3D shape of the core pocket in the molded drum. Therefore, the desired increase in thickness of the central absorbent area relative to the outer absorbent area may not be achieved. It is believed that an upper nonwoven layer with the circular curvature described herein allows the upper nonwoven to form around the complex 3D shape of the inner core layer, resulting in an absorbent core structure that better conforms to the wearer's unique genital geometry and minimizes gaps between the absorbent article and the body (in which fluid can bypass the article and soil underwear or clothing).

[0101] In some configurations, the upper nonwoven layer can also have a thickness greater than approximately 100 mm. 3 / mm 2 / min, approximately 100mm 3 / mm 2 / min to approximately 500mm 3 / mm 2 The air permeability is measured as per the air permeability method. Unrestricted by theory, it is believed that with a permeability greater than approximately 100 mm... 3 / mm 2A permeability of / min allows sufficient airflow through the nonwoven fabric to properly guide the liquid absorbent material into the core pocket within the molding drum. It is believed that if the upper nonwoven layer has a permeability of less than approximately 100mm... 3 / mm 2 If the permeability is less than 1 / min, insufficient airflow may occur, and the core pocket may not be completely filled with liquid absorbent material, and / or the weight of liquid absorbent material between adjacent pockets may vary.

[0102] In some configurations, the polymer fibers in the upper nonwoven layer and the polymer fibers in the lower nonwoven layer can be different. In some configurations, the polymer fibers in the upper nonwoven layer and the polymer fibers in the lower nonwoven layer can be the same. In some configurations, the upper nonwoven layer can be a carded nonwoven fabric. In some configurations, the upper nonwoven layer can be air-through bonded or hydroentangled. In some configurations, the upper nonwoven layer is not a spunbond material.

[0103] Suitable examples of nonwoven materials may include, but are not limited to, the following: (i) a 40gsm carded elastic nonwoven material (material code; ATB Z87G-40-90) manufactured by Yanjan China, which is a carded nonwoven composed of a blend of 60% 2dtex and 40% 4dtex BiCo (PE / PET) fibers. The fibers are bonded (ATB = bonded by “hot” air) to create a wet elastic network. Without being theoretically limited, it is believed that this material exhibits low permanent strain (less than about 0.013 mm / mm) and sufficient dry recovery energy (greater than about 0.03 N) in the dry CD ultrasensitive 3-point bending test due to the presence of 4dtex BiCo fibers and the fiber-to-fiber bonded BiCo network. (ii) A 55gsm elastic jet-spun web material (material code: 53FC041001) manufactured by Sandler Germany, which is a hydroentangled nonwoven fabric produced by a carding step (as described above for nonwoven fabrics) followed by an elevated drying step (as described in U.S. Patent Publication No. 2020 / 0315873A1), which produces an entangled and BiCo-bonded elastic network. It comprises a blend of 30% 10dtex HS-PET, 50% 2.2dtex BiCo (PE / PET), and 20% 1.3dtex rayon fibers. In the dry CD ultrasensitive 3-point bending method, this material exhibits low permanent strain (less than about 0.013 mm / mm) and sufficient dry recovery energy (greater than about 0.03 N). (ii) a 50 gsm elastic jet-spun web material (material code: 53FC041005 opt82) manufactured by Sandler Germany, which is a spunlace nonwoven fabric produced via a carding step (as described above for nonwoven fabrics) followed by an elevated drying step (as described in U.S. Patent Publication No. 2020 / 0315873A1), which produces an entangled and BiCo-bonded elastic network. It comprises a blend of 60% 5.8 dtex BiCo (PE / PET), 20% 3.3 dtex trefoil “structured” rayon, and 20% 1.3 dtex rayon. In the dry CD ultrasensitive 3-point bending method, this material exhibits low permanent strain (less than approximately 0.013 mm / mm) and sufficient dry recovery energy (greater than approximately 0.03 N). (mm). Although the material contains 40% rayon that softens when wet, the use of structural trilobal rayon fibers contributes to structural stability in the wetted state.

[0104] By adjusting pore size, volume, and quantity through the selection of appropriate fiber size, basis weight, and degree of consolidation, manufacturers may wish to select fiber compositions with specific surface chemistry properties, such as fibers with hydrophobic surfaces, hydrophilic surfaces, or blends of different fibers and / or their z-direction layering or gradients. Fibers with hydrophilic surfaces will tend to attract and move the aqueous components of menstrual fluid in a manner that facilitates rapid fluid collection after wicking and expulsion. However, the advantage of hydrophilic fiber surfaces within the topsheet may simultaneously increase the topsheet's tendency to re-absorb fluid from the underlying absorbent assembly (rewetting), potentially leading to an undesirable wetting sensation for the user. On the other hand, fibers with hydrophobic surfaces will tend to repel the aqueous components of menstrual fluid and / or resist fluid movement along their surface, thus tending to resist wicking but also resisting rewetting. For any given product design, a manufacturer may seek an appropriate balance in selecting constituent fibers with hydrophilic surfaces, fibers with hydrophobic surfaces, or blends thereof and / or z-direction layering, combining fiber size, fiber consolidation level, and the resulting top sheet pore size, volume, and number.

[0105] The inner core layer can contain any of the various liquid absorbent materials commonly used in absorbent articles, such as pulverized wood pulp (often referred to as breathable felt). A suitable core material is breathable felt material available under code FR516 from Weyerhaeuser Company (Washington, USA). Examples of other suitable liquid absorbent materials that can be used in the core may include crepe cellulose filler; including co-formed meltblown polymers; chemically hardened, modified, or cross-linked cellulose fibers; synthetic fibers such as crimped polyester fibers; peat moss; cotton; bamboo; absorbent polymer materials; or any equivalent material or combination of materials, or mixtures thereof.

[0106] Absorbent polymer materials used in absorbent articles typically include water-insoluble, water-swellable, hydrogel-forming crosslinked absorbent polymers that can absorb large amounts of liquid and retain such absorbed liquid under moderate pressure.

[0107] The absorbent polymer material used in the absorbent core according to this disclosure may include superabsorbent particles, also known as “superabsorbent material” or “absorbent gel material.” The absorbent polymer material (typically in particulate form) may be selected from polyacrylates and polyacrylate-based materials, such as, for example, partially neutralized, cross-linked polyacrylates. The term “particle” refers to granules, fibers, flakes, spheres, powders, sheets, and other shapes and forms known to those skilled in the art of superabsorbent particles. In some aspects, superabsorbent particles may be in the shape of fibers, i.e., elongated needle-like superabsorbent particles.

[0108] In some configurations, the core layer may comprise cellulose fibers and superabsorbent particles. The core layer may comprise approximately 50% to 85%, or approximately 55% to approximately 80%, or approximately 60% to approximately 75% of cellulose fibers by weight of the core layer. The core layer may comprise approximately 10% to approximately 50%, or approximately 15% to approximately 50%, or approximately 20% to approximately 40%, or approximately 25% to approximately 35% of superabsorbent particles by weight of the core layer. In some configurations, the core layer may comprise approximately 125 gsm to approximately 500 gsm of cellulose fibers. In some configurations, the core layer may comprise approximately 125 gsm to approximately 300 gsm of superabsorbent particles.

[0109] In some configurations, the inner core may contain about 50% to about 85% cellulose fibers and about 15% to about 50% superabsorbent particles.

[0110] The absorbent material 20 can be elastic and conformable, and can deliver a superior user experience without significantly bunching and / or compression. The absorbent material can be exposed to physical forces and can return to its original state.

[0111] Top Sheet

[0112] The top sheet 110 can be formed from any suitable nonwoven web or molded film material. Referring back to the accompanying drawings, the top sheet 110 is positioned adjacent to the wearer-facing surface of the absorbent article 20 and can be joined thereto and to the bottom sheet 130 by any suitable attachment or adhesive method. The top sheet 110 and the bottom sheet 130 can be directly joined to each other in the outer peripheral region outside the periphery of the absorbent core structure, and can also be indirectly joined by directly joining them to the wearer-facing and outward-facing surfaces of the absorbent article, respectively, or by including additional optional layers in the absorbent article.

[0113] The absorbent article 20 may have any topsheet 110 known to be otherwise effective, such as a soft, gentle-feeling topsheet that is non-irritating to the wearer's skin. Suitable topsheet materials will include liquid-permeable materials that are comfortable in contact with the wearer's skin and allow the expelled menstrual fluid to permeate quickly. Some suitable examples of topsheet materials include membranes, nonwovens, and laminated structures having membrane / nonwoven layers, membrane / membrane layers, and nonwoven / nonwoven layers.

[0114] Non-limiting examples of nonwoven fiber web materials that may be used as top sheet 110 include fibrous materials made of natural fibers, modified natural fibers, synthetic fibers, or combinations thereof. Some suitable examples are described in U.S. Patent Nos. 4,950,264, 4,988,344, 4,988,345, 3,978,185, 7,785,690, 7,838,099, 5,792,404, and 5,665,452.

[0115] Topsheet 110 may be soft, comfortable to the touch, and non-irritating to the wearer's skin. Furthermore, topsheet 110 may be liquid-permeable, allowing liquids (e.g., urine, menstrual fluid) to easily pass through its thickness. Some suitable examples of topsheet materials include membranes, nonwovens, and laminated structures having membrane / nonwoven layers, membrane / membrane layers, and nonwoven / nonwoven layers. Other exemplary topsheet materials and designs are disclosed in U.S. Patent Application Publications Nos. 2016 / 0129661, 2016 / 0167334, and 2016 / 0278986.

[0116] In some examples, topsheet 110 may include clusters, as described in US 8,728,049, US 7,553,532, US 7,172,801, US 8,440,286, US 7,648,752, and US 7,410,683. Topsheet 20 may have a pattern of discrete, hair-like fibrils as described in US 7,655,176 or US 7,402,723. Additional examples of suitable topsheet materials include those described in US 8,614,365, US 8,704,036, US 6,025,535, and US Patent Publication No. 2015 / 041640. Another suitable topsheet may be formed from a three-dimensional substrate, as detailed in US 2017 / 0258647. The top sheet may have one or more layers, as described in U.S. Patent Publications 2016 / 0167334, 2016 / 0166443, and 2017 / 0258651.

[0117] In some examples, the top sheet 110 may be formed of a nonwoven web material of a spunbond web, which includes monocomponent continuous fibers, or alternatively, bicomponent or multicomponent fibers, or blends of monocomponent fibers spun from different polymer resins, or any combination thereof. The top sheet may also be a shaped nonwoven top sheet, as disclosed in U.S. Patent Publication No. 2019 / 0380887.

[0118] To ensure that fluid contacting the top (wearer-facing) surface of the topsheet moves appropriately and rapidly in the z-direction to the bottom (outer-facing) surface of the topsheet, where it can be drawn into the absorbent article, it is important that the nonwoven web material forming the topsheet has an appropriate weight / volume density, reflecting the proper presence of interstitial channels (sometimes called "pores") within and between the constituent fibers through which fluid can move within the nonwoven material. In some cases, nonwoven materials with excessively densely bound fibers may have insufficient number and / or volume and / or size of pores, and the nonwoven material will obstruct rather than facilitate rapid downward fluid movement in the z-direction. On the other hand, nonwoven materials with fibers that are too large and / or insufficiently bound to provide a degree of opacity (for the purpose of concealing the absorbed fluid in the underlying layers) and a striking appearance may be negatively perceived by the user.

[0119] The thickness of the topsheet material can be controlled to balance the competing demands for opacity and bulk (which require higher thickness) with the limitation on the z-direction distance that the discharged fluid travels from the wearer-facing surface through the topsheet to the outward-facing surface to reach the underlying absorbent core structure. Therefore, it may be desirable to control the manufacture of the topsheet material to produce a thickness of about 0.20 mm to about 1.0 mm, or about 0.25 mm to about 0.80 mm, or about 0.30 mm to about 0.60 mm.

[0120] Second Top Sheet (STS)

[0121] In some cases, the STS layer can be included between the top sheet and the absorber core structure so that the absorber core structure can easily receive a sudden discharge of fluid and, after receiving it, wick the fluid along the x and y directions to distribute the fluid onto the absorber core structure below.

[0122] If included, the STS can be a nonwoven fibrous structure, which may include cellulose fibers, non-cellulose fibers (e.g., fibers spun from polymer resins), or blends thereof. To accommodate the folding and lateral aggregation of the absorbent article 20 and the absorbent core structure 10, as described herein, the STS can be formed of a relatively flexible material (i.e., having relatively low flexural stiffness).

[0123] Suitable STS compositions and structures, and numerous specific examples of their combinations with suitable topsheet compositions and structures, are further described in U.S. Patent Serials 16 / 831,862, 16 / 831,854, 16 / 832,270, 16 / 831,865, 16 / 831,868, 16 / 831,870, and 16 / 831,879, and U.S. Provisional Application Serials 63 / 086,610 and 63 / 086,701. Additional suitable examples are described in U.S. 9,504,613; U.S. 2012 / 040315; and U.S. 2019 / 0021917.

[0124] In some configurations, the absorbent article may not contain a second top sheet.

[0125] Backsheet

[0126] The film 130 can be positioned below or near the outward-facing surface of the absorbent core structure 10 and can be bonded thereto by any suitable attachment method. For example, the film 130 can be secured to the absorbent core structure 10 by a uniform, continuous layer of adhesive, a patterned layer of adhesive, or an array of adhesive separation lines, spirals, or dots. Alternatively, the attachment method may include thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other suitable attachment mechanism or combination thereof. In other examples, it is conceivable that the absorbent core structure 10 is not directly bonded to the film 130.

[0127] The film 130 may be impermeable or substantially impermeable to aqueous liquids (e.g., urine, menstrual fluid) and may be made of a thin plastic film, although other liquid-impermeable flexible materials may also be used. As used herein, the term "flexible" refers to a material that is compliant and readily conforms to the general shape and contours of the human body. The film 130 may prevent or at least substantially inhibit the escape of fluids absorbed and contained within the absorbent core structure 10 from reaching clothing articles, such as underwear and outerwear, that may come into contact with the absorbent article 20. However, in some cases, the film 130 may be made and / or adapted to allow vapors to escape from the absorbent core structure 10 (i.e., the film is made breathable), while in other cases, the film 130 may be made so as not to allow vapors to escape (i.e., it is made impermeable). Thus, the film 130 may comprise a polymer film, such as a thermoplastic film of polyethylene or polypropylene. Suitable materials for the film 130 are, for example, thermoplastic films with a thickness of about 0.012 mm (0.5 mils) to about 0.051 mm (2.0 mils). Any suitable film known in the art can be used in this invention.

[0128] Suitable examples of materials suitable for forming film are described in US 5,885,265, US 4,342,314, and US 4,463,045. Suitable single-layer breathable films for use herein include, for example, those described in GB A 2184 389, GB A 2184 390, GB A 2184 391, US 4,591,523, US 3,989,867, US 3,156,242, WO 97 / 24097, US 6,623,464, US 6,664,439, and US 6,436,508.

[0129] Film 130 may have two layers: a first layer comprising a vapor-permeable pore-formed membrane layer and a second layer comprising a breathable microporous membrane layer, as described in US 6,462,251. Other suitable examples of bilayer or multilayer breathable films used herein include those described in US 3,881,489, US 4,341,216, US 4,713,068, US 4,818,600, EP 203821, EP 710 471, EP 710 472 and EP 0 793 952.

[0130] Other Features

[0131] In some configurations, absorbent article 20 may include underwear fastening components, such as underwear fastening adhesives or hook-and-loop fastening systems (such as VELCRO). ® ) components.

[0132] In some configurations, the absorbent article 20 may be provided with a panty-fastening adhesive disposed on the garment-facing side of the backing 130 to provide a mechanism for the user to adhere the absorbent article to the inside of her panties in her crotch area. The panty-fastening adhesive may include any adhesive or glue in the art for such purposes. These adhesives are typically pressure-sensitive and remain tacky well below their application temperature. In some configurations, the panty-fastening adhesive may be a pressure-sensitive hot melt adhesive. When the absorbent article 20 is encapsulated for transport, handling, and storage prior to use, the panty-fastening adhesive may be covered with one or more sheets of release film or paper (not shown) that cover / shield the adhesive deposit from contact with other surfaces until the user is ready to remove the release film or paper and place the absorbent article in her panties for wear / use. The release film or paper may also be used as personalized packaging of the article or to provide disposal functionality as known in the art. Any commercially available release paper or film may be used. Suitable examples include BL 30 MG-ASILOX EI / O and BL 30 MG-A SILOX 4 P / O from Akrosil, and M&W membranes from Gronau (Germany) under code X-5432. In some configurations, the absorbent article may be packaged in a bi-fold or tri-fold configuration.

[0133] In some configurations, the absorbent article 20 may include opposing wings 140, 150 on each side, these opposing wings extending laterally outward from a first longitudinal side 141 and a second longitudinal side 151 of the absorbent article. Wings are currently commonly provided on feminine hygiene absorbent articles. As provided, they typically have an adhesive deposit applied to their outward-facing surface (which is outward-facing before the absorbent article is placed inside the user's underwear and the wings are applied). The wings may also include the adhesive deposit described above, which allows the user to wrap the wings around the inner edge of the leg opening of the underwear and adhere the wings to the outward-facing surface / underside of the underwear in the crotch area, thereby providing supplemental retaining support for the absorbent article and helping to protect the underwear near its leg edges from soiling.

[0134] Test Methods

[0135] Layers of Interest

[0136] For any of the following methods for all component layers of the article that are not tested, the layer of interest may be separated from the untested layers using cryo-spray as needed.

[0137] Strain at Break Method

[0138] The force-displacement behavior of the samples was measured on a universal constant-rate elongation test frame equipped with a load sensor (suitable instrument being an MTS Alliance instrument using TestSuite software, purchased from MTS Systems Corp., Eden Prairie, MN, or equivalent), with the measured force within 1% to 99% of the load sensor's limits. The samples were stretched at a constant rate (mm / sec) until fracture, and the percentage of fracture strain was measured. All tests were conducted in a room controlled at 23°C ± 3°C and 50% ± 2% relative humidity, with the test samples conditioned in this environment for at least 2 hours prior to testing.

[0139] The clamps used to hold the test specimens are lightweight (<80 grams), vise-like clamps with a semi-cylindrical steel gripping surface at least 40 mm wide and rubber-coated steel. The clamps are mounted on a universal test frame and are installed such that they are aligned horizontally and vertically with each other.

[0140] Test specimens taken from raw material rolls or sheets, or from material layers removed from absorbent articles, are measured. When removing material layers from absorbent articles, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive and any fibers that may have transferred from the underlying layer. To ensure the removal of all adhesive and any transferred fibers, the layer is immersed in a suitable solvent that will dissolve the adhesive and release any transferred fibers present without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly to prevent excessive stretching or other deformation of the material. After the material has dried, the test specimens are prepared as follows: The test specimens are cut from an area of ​​the test material that is free of any creases or wrinkles. The test specimens are 100 mm long (parallel to the transverse axis, or the intended transverse axis of the article) and 25.4 mm wide (parallel to the longitudinal axis, or the intended longitudinal axis of the article). Five duplicate test specimens are prepared in a similar manner.

[0141] Prepare the general test frame as follows. Set the initial clamp-to-clamp spacing to a nominal gauge length of 80 mm, then zero the clamps. Program the test frame to move the clamps closer together with an intentional 1 mm relaxation to ensure no preload on the test specimen at the start of the test. (During this movement, the specimen will become relaxed between the clamps.) Next, the clamps will be moved away at a relaxation rate of 1 mm / s until a relaxation preload of 0.05 N is exceeded. (At this point, the clamp position signal is used to calculate the sample relaxation, adjusted gauge length, and strain is capped at zero, 0.0). The clamps will then be moved away at a rate of 1 mm / s until the sample breaks or exceeds the instrument's extension limit.

[0142] The test specimen is inserted into the clamp so that its long axis is parallel to and centered with the movement of the clamp. The test begins and force (“load”) and displacement data are continuously collected at a data acquisition rate of 100 Hz.

[0143] Plot a load (N) versus displacement (mm) curve. Determine the peak load from the curve, and then determine the fracture sensitivity as follows. After reaching the peak load, determine the clamp position where the load signal decreases by 75%, and record this as the final specimen length (Lf), accurate to 0.01 mm. The initial specimen length is defined by the clamp position when a relaxation preload of more than 0.05 N is applied, and this value is recorded as the initial specimen length (Li), accurate to 0.01 mm. Calculate the percentage of fracture strain as follows, and record it, accurate to 1%.

[0144] % Fracture strain = ((Lf–Li) / Li) 100

[0145] Repeat the procedure for all five repeated test specimens in a similar manner. Calculate the arithmetic mean of the fracture strain % for the five repeated test specimens and report it as fracture strain %, accurate to 1%.

[0146] Dry CD Super Sensitive 3-Point Bend Method

[0147] The CD (lateral) bending characteristics of the test samples were measured using an ultrasensitive 3-point bending test on a universal constant-speed extension test frame equipped with a load sensor suitable for measuring forces (suitable instruments include MTS Alliance instruments using TestSuite software, purchased from MTS Systems Corp., Eden Prairie, MN, or equivalents). The intent of this method is to simulate the deformation in the xy-plane produced by the wearer of the absorbent material during normal use. All tests were conducted in a room controlled at 23°C ± 3°C and 50% ± 2% relative humidity, with the test samples conditioned in this environment for at least 2 hours prior to testing.

[0148] The ultrasensitive three-point bending method aims to maximize the force signal-to-noise ratio when testing materials with very low bending forces. This is achieved by using a highly sensitive load cell (e.g., 5 N), a small span (the load is proportional to the cube of the span), and a wide specimen width (the total load measured is proportional to the width). The fixture is designed so that bending measurements are performed under tension, allowing for minimal fixture mass. Noise in the force signal is minimized by keeping the load cell stationary to reduce mechanical vibration and inertial effects, and by keeping the mass of the fixture attached to the load cell as low as possible.

[0149] See Figures 15A-15CThe load sensor 1001 is mounted on the fixed clamp of the universal test frame. The ultra-sensitive clamp 1000 consists of three thin blades made of a lightweight, rigid material (such as aluminum or equivalent). Each blade has a thickness of 1.0 mm, rounded edges, and a length capable of accommodating a bending width of 100 mm. Each blade has cavities 1004a and 1004b (outer blades) and 1005 (center blade), which are cut out to form a blade material with a height h of 5 mm along its horizontal edge. The two outer blades 1003a and 1003b are horizontally mounted to the movable clamp of the universal test frame, aligned parallel to each other with their horizontal edges vertically aligned. The span s between the two outer blades 1003a and 1003b is 5 mm ± 0.1 mm (inner edge to inner edge). The center blade 1002 is mounted on the fixed clamp of the universal test frame as a load sensor. When in place, the center blade 1002 is parallel to the two outer blades 1003a and 1003b, and centered on the midpoint between the outer blades 1003a and 1003b. The blade fixture includes integrated adapters adapted to be mounted in the appropriate positions on the universal test frame and locked in place such that the horizontal edge of the blade is orthogonal to the movement of the universal test frame crossbeam.

[0150] Test specimens are taken from rolls or sheets of raw material or from layers of material removed from the absorbent article. When removing the material layer from the absorbent article, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive and any fibers that may have transferred from the underlying layer. To ensure the removal of all adhesive and any transferred fibers, the layer is immersed in a suitable solvent that will dissolve the adhesive and release any transferred fibers present without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly to prevent excessive stretching or other deformation of the material. After the material has dried, test specimens are obtained as follows: Test specimens are cut from an area of ​​the test material that is free of any creases or wrinkles. Dry test specimens for CD bending (i.e., bending perpendicular to the transverse axis of the sample) were prepared as follows: the specimen was cut along CD (transverse; parallel to the transverse axis of the sample) to a width of 50.0 mm and along MD (longitudinal; parallel to the longitudinal axis of the sample) to a length of 100.0 mm, maintaining their orientation after cutting, and marking the surface facing the body (or the surface intended to face the finished product). Five repeatable dry test specimens were prepared in a similar manner.

[0151] The general-purpose test frame was programmed such that the movable chuck was set to move at a rate of 1.0 mm / s in the direction opposite to the fixed chuck. The chuck movement began with the specimen 1006 lying flat on the outer blades 1003a and 1003b without deflection, and continued as the inner horizontal edge of the cavity 1005 in the central blade 1002 contacted the top surface of the specimen 1006, further extending by an additional 4 mm of chuck movement. The chuck stopped at 4 mm and then immediately returned to zero at a rate of 1.0 mm / s. Force (N) and displacement (mm) were collected at 50 Hz throughout the process.

[0152] Before loading the test specimen 1006, the outer blades 1003a and 1003b move toward the central blade 1002, and then past the central blade, until a gap C of approximately 3 mm exists between the inner horizontal edges of the cavities 1004a and 1004b in the outer blades 1003a and 1003b and the inner horizontal edge of the cavity 1005 in the central blade 1002 (see [link to test specimen 1006]). Figure 15C The specimen 1006 is placed within the gap C such that it spans the inner horizontal edges of cavities 1004a and 1004b in the outer blades 1003a and 1003b, oriented such that the MD (short side) of the specimen is perpendicular to the horizontal edges of the blades and the body-facing surface of the specimen is upward. The specimen 1006 is centered between the outer blades 1003a and 1003b. The outer blades 1003a and 1003b are slowly moved along a direction opposite to the fixed clamp until the inner horizontal edge of cavity 1005 in the central blade 1002 contacts the top surface of the specimen 1006. The test begins, and force and displacement data are continuously collected.

[0153] Force (N) versus displacement (mm) was plotted. The maximum peak force was recorded, accurate to 0.001 N. The area under the curve from the load start to the maximum peak force was calculated and recorded as bending energy, accurate to 0.001 N. mm. The recovery energy is calculated as the area under the curve of the force unloading from the maximum peak to 0.0 N, and recorded as the recovery energy, accurate to 0.001 N. mm. In a similar manner, the entire test sequence was repeated for a total of five dry test specimens and five wet test specimens.

[0154] For each test specimen, calculate the arithmetic mean of the maximum peak force among similar specimens, accurate to 0.001 N, and record it as the dry peak load. For each test specimen, calculate the arithmetic mean of the bending energy among similar specimens, accurate to 0.001 N. mm, and report as dry bending energy. For each test specimen, calculate the arithmetic mean of the recovery energy in similar specimens, accurate to 0.001 N. mm, and report as dry recovery energy.

[0155] CD Cycle Elongation to 3% Strain Method

[0156] The cyclic tensile and recovery response of absorbent article specimens was measured using a universal constant-rate elongation test frame for ten cycles of sustained load application (“elongation”) and load removal (“recovery”). The test specimen was cycled ten times to 3% of the engineering strain and then returned to zero engineering strain. For each cycle, the stiffness, peak load, normalized peak energy, normalized recovery energy, strain at the start of the cycle, and strain at the end of the cycle (i.e., “permanent strain”) were calculated and reported. The intent of this method is to understand the ability of a specimen to be stretched in the xy-plane due to body forces and then recover to its original state. All measurements were performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, with the test specimens conditioned in this environment for at least 2 hours prior to testing.

[0157] A suitable universal constant-speed extension test frame is an MTS Alliance or equivalent that interfaces with a computer running TestSuite control software (purchased from MTS SystemsCorp, Eden Prairie, MN). The universal test frame is equipped with a load sensor, and the force being measured is within 1% to 99% of the sensor's limits. The clamps used to hold the test specimen are lightweight (<80 grams) vise-like clamps with a blade or serrated edge clamping surface at least 40 mm wide. The clamps are mounted on the universal test frame and are installed such that they are horizontally and vertically aligned with each other.

[0158] Test specimens are taken from rolls or sheets of raw material or from a layer of material removed from an absorbent article. When cutting the material layer from the absorbent article, care is taken not to contaminate or deform the layer during the process. The removed layer should be free of residual adhesive and any fibers that may have transferred from the underlying layer. To ensure the removal of all adhesive and any transferred fibers, the layer is immersed in a suitable solvent that will dissolve the adhesive and release any transferred fibers present without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly in a manner that prevents excessive stretching or other deformation of the material. After the material has dried, the test specimen is obtained. The test specimen is cut from any area of ​​the test material free of creases or wrinkles. The test specimen is the same length as the transverse length of the article (parallel to the transverse axis of the article, or the intended transverse axis of the article). When cutting specimens from absorbent articles of different sizes and widths, the total specimen length (L) 总计The results may vary from product to product, therefore the results will be normalized to compensate for this variation. The test specimen has a width of 25.4 mm (parallel to the longitudinal axis of the article or the expected longitudinal axis). Specimen width (w) = 25.4 mm. Measure and record the total specimen length (L). 总计 (Accurate to 0.1 mm). Prepare five repeat test specimens in a similar manner.

[0159] The thickness (t) of the test specimen was measured using a manually operated micrometer equipped with a capability to apply 0.1 psi. + A pressure foot with a stable pressure of 0.01 psi. This manually operated micrometer is a heavy-duty instrument with readings accurate to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic from VWR International, or an equivalent. The pressure foot is a flat, circular, movable surface with a diameter not exceeding 25.4 mm. The test specimen is supported by a horizontal, flat reference platform that is larger than and parallel to the surface of the pressure foot. Zero the micrometer against the horizontal, flat reference platform. Place the test specimen on the platform, centered below the pressure foot. Manually press the micrometer at 3... + The pressure foot is lowered at a descent rate of 1 mm / s until the full weight of the pressure is applied to the specimen. After 5 seconds, the thickness is recorded as the specimen thickness (t), accurate to 0.01 mm.

[0160] Prepare a general test frame as follows. Set the initial clamp-to-clamp spacing to a nominal gauge length (L) shorter than the total specimen length. 标称 ), and allows the sample to be securely clamped at both ends (i.e., L 标称 <L 总计 Then the clamps are zeroed. The test frame is programmed to move the clamps closer together with an intentional 1mm relaxation to ensure there is no pre-tension on the test specimen at the start of the test. (During this movement, the specimen will become relaxed between the tension clamps.) Next, the clamps will be moved away at a relaxation rate of 1mm / s until a relaxation preload of more than 0.05N is achieved. At this point, the following holds true: 1) The clamp position signal (mm) is defined as the specimen relaxation (L). 松弛 2) The initial gauge length (L0) is calculated as the nominal gauge length plus the relaxation L0 = L 标称 +L 松弛The units are in millimeters. 3) The chuck extension (ΔL) is set to zero (0.0 mm). 4) The chuck displacement (mm) is set to zero (0.0 mm). At this position, the engineering strain is zero, 0.0. The engineering strain is calculated as the length change (ΔL) divided by the initial length (L0). Engineering strain = ΔL / L0. For one test cycle, the clamps are moved away at an initial speed of 1 mm / s until the engineering strain endpoint exceeds 0.03 mm / mm, and then the clamps are moved towards each other at an initial speed of 1 mm / s until the chuck return position when the chuck signal becomes less than 0 mm. This test cycle is repeated until a total of 10 cycles are completed.

[0161] The test specimen is inserted into the clamp so that its long axis is parallel to and centered with the movement of the clamp. The test begins and time, force, and displacement data are continuously collected at a data acquisition rate of 100 Hz.

[0162] Plot the load (N) versus displacement (mm) for all ten cycles. For each cycle, perform the following: Record the peak load to an accuracy of 0.01 N. Calculate the peak energy (E). 峰值 The area under the load-displacement curve from the start of the cycle to the strain endpoint of 0.03 mm / mm (during the loading portion of the cycle) is recorded, accurate to 0.01 N. mm. Calculate the return energy (E) 返回 The area under the load-displacement curve from the strain endpoint of 0.03 mm / mm to the chuck return at 0 mm (during the unloading portion of the cycle) is recorded as the recovery energy, accurate to 0.01 N. mm. Normalized peak energy (NE) 峰值 The calculation is the peak energy divided by the initial length, where NE 峰值 =E 峰值 / L0, and record it, accurate to 0.01mN. Return the normalized energy (NE). 返回 The calculation is the return energy divided by the initial length (NE). 返回 =E 返回 / L0), and record it, accurate to 0.01mN. NE 峰值 and NE 返回 The unit is millinewtons (mN).

[0163] Now plot the stress (σ) versus strain curves for all ten cycles, and perform the following operations for each cycle. (In N / mm) 2 The engineering stress in units is the load divided by the cross-sectional area of ​​the specimen, where the cross-sectional area is the specimen width (w) multiplied by the thickness (t), σ = load / (w) For the line between the point of minimum force and the point of maximum force (during the cyclic loading phase), determine the modulus or the slope of the stress-strain curve and record it as the modulus, accurate to 0.01 N / mm. 2 The stiffness is calculated by multiplying the modulus by the specimen thickness and recorded as tensile stiffness, accurate to 0.01 N / mm. The strain of the test specimen at the start of the cycle is defined as the strain when the load exceeds the relaxation preload of 0.05 N (during the loading portion of the cycle) and recorded as the initial strain of the cycle, accurate to 0.01 mm / mm. The strain of the test specimen at the end of the cycle is defined as the strain when the load becomes less than the 0.05 N preload of the cycle (during the unloading portion of the cycle) and recorded as the permanent strain, accurate to 0.01 mm / mm. The entire procedure is now repeated for all five repetitions in a similar manner.

[0164] For each of the ten cycles, the arithmetic mean of the parameters in the five repeated test specimens is calculated and reported as peak load (accurate to 0.01 N), normalized peak energy (accurate to 0.01 mN), normalized recovery energy (accurate to 0.01 mN), tensile stiffness (accurate to 0.01 N / mm), initial strain of the cycle (accurate to 0.01 mm / mm), and permanent strain (accurate to 0.001 mm / mm).

[0165] Structural Bond Site Pattern Spacing and Area Measurement Method

[0166] On images of absorbent article samples acquired using a flatbed scanner, the spacing between discrete structural bonding sites used to create the quilted pattern on the absorbent article sample, and the total area occupied by the sum of these elements in a specified region of the sample, were measured. The scanner was capable of scanning in reflective mode at a resolution of 2400 dpi and 8-bit grayscale. A suitable scanner was the Epson Perfection V750 Pro, or equivalent, from Epson America Inc., Long Beach, CA. The scanner interacted with a computer running an image analysis program. A suitable program was ImageJ v. 1.52, National Institute of Health, USA, or equivalent. The sample images were distance-calibrated against a ruler image acquired by NIST. To achieve maximum contrast, the samples were backed against an opaque, uniformly colored black background before image acquisition. All tests were performed in a conditioning chamber maintained at approximately 23 ± 2°C and approximately 50 ± 2% relative humidity.

[0167] Prepare each test sample as follows. Remove the absorbent material from any existing packaging paper. If the material is folded, gently unfold it and smooth out any wrinkles. If wings are present, extend them, but keep the release paper intact. Condition the test samples for 2 hours at a temperature of approximately 23°C ± 2°C and a relative humidity of approximately 50% ± 2%.

[0168] Obtain the image as follows. Place the ruler on the scanning bed with its orientation parallel to the side of the scanner glass. Acquire an image of the ruler (calibration image) in reflective mode at a resolution of 2400 dpi (approximately 94 pixels / mm) and 8-bit grayscale. Save the calibration image as an uncompressed TIFF file. After obtaining the calibration image, remove the ruler from the scanner glass and scan the test sample under the same scanning conditions as follows. Place the test sample in the center of the scanner glass and hold it in place, if necessary, so that it lies flat with the body-facing surface of the sample facing the scanner glass surface. Orient the sample so that the entire sample is within the glass surface. Place a black background on top of the sample, close the scanner lid, and acquire a scan image of the entire sample with the same settings as for the calibration image. Save the sample image as an uncompressed TIFF file.

[0169] The following analysis is performed on the sample image. Open the calibration image file in the image analysis program and use the imaging ruler to calibrate the image resolution to determine the number of pixels per millimeter. Now open the sample image in the image analysis program and set the distance scale using the image resolution determined from the calibration image. Now visually inspect the pattern of embossed elements present on the sample in the image and identify the pattern area to be analyzed. For example, an absorbent article can be divided into three equal-length areas in the longitudinal direction, such as the front third area (area 1), the middle third area (area 2), and the rear third area (area 3). Use the image analysis tool to draw a shape along the outer perimeter of the first discrete area to be analyzed. Measure the area of ​​this first area and record it as the total area of ​​area 1, accurate to 0.01 mm. 2 Now, measure the area of ​​each individual, discrete embossing element located inside the perimeter of zone 1 as follows. Draw a minimum boundary circle around each individual embossing element such that no part of the embossing element lies outside the boundary circle. Now measure the area of ​​the boundary circle of the embossing element and record the area of ​​the embossing element, accurate to 0.01 mm. 2 Similarly, the area of ​​each embossed element, including the portion of the embossed element located within zone 1, is measured and recorded to an accuracy of 0.01 mm. 2 Now, sum the areas of all embossed elements in zone 1 and record the total embossed element area of ​​zone 1, accurate to 0.01 mm. 2The total area of ​​embossed elements in zone 1 is divided by the total area of ​​zone 1, then multiplied by 100, and recorded as the percentage of the total area of ​​zone 1 occupied by the embossed elements. The spacing between each discrete embossed element in zone 1 is measured as follows. As described herein, the distance from the center of the smallest boundary circle drawn around the discrete embossed element in zone 1 to the center of the smallest boundary circle drawn around the nearest neighbor discrete embossed element in zone 1 is measured and recorded as the embossed spacing, accurate to 0.01 mm. In a similar manner, this is repeated for all adjacent embossed elements in zone 1, and each distance is recorded to an accuracy of 0.01 mm. The arithmetic mean of all measured embossed spacings between the nearest neighbors in zone 1 is now calculated and recorded as the embossed spacing of zone 1, accurate to 0.01 mm.

[0170] In a similar manner, the entire procedure was repeated for each additional zone containing embossed elements present on the test sample, and marked accordingly as zone 2, zone 3, etc.

[0171] Nonwoven Thickness-Pressure Method

[0172] The thickness of the test specimen is measured as the distance between the reference platform on which the specimen rests and the pressure foot on which a specified amount of pressure is applied to the specimen over a specified time. For the purposes of this paper, two different confining pressures (7 g / cm²) are used. 2 and 70g / cm 2 Thickness was measured and reported. All measurements were performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the test specimens were conditioned in this environment for at least 2 hours prior to testing.

[0173] The thickness was measured using a manually operated micrometer equipped with a stable pressure (7 g / cm³). 2 and 70g / cm 2 The pressure foot is applied to the test specimen. This manually operated micrometer is a heavy-duty instrument with readings accurate to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, or equivalent, from VWR International. The pressure foot is a flat, circular, movable surface with a diameter smaller than the test specimen, capable of applying the required pressure. A suitable pressure foot has a diameter of 25.4 mm, but smaller or larger pressure feet can be used depending on the size of the specimen being measured. The test specimen is supported by a horizontal, flat reference platform that is larger than and parallel to the surface of the pressure foot. The system is calibrated and operated according to the manufacturer's instructions.

[0174] Test specimens taken from raw material rolls or sheets, or from material layers removed from absorbent articles, are measured. When removing material layers from absorbent articles, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive and any fibers that may have transferred from the underlying layer. To ensure the removal of all adhesive and any transferred fibers, the layer is immersed in a suitable solvent that will dissolve the adhesive and release any transferred fibers present without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly to prevent excessive stretching or other deformation of the material. Once the material is dry, a test specimen is obtained from an area free of creases or wrinkles, and it must be larger than the pressure foot.

[0175] In order to achieve 7g / cm 2 To measure the thickness under confining pressure, first zero the micrometer relative to a horizontal, flat reference platform. Place the test specimen on the platform, with the test position centered below the pressure foot. Gently lower the pressure foot at a rate of 3.0 mm ± 1.0 mm per second until full pressure is applied to the test specimen. Wait 5 seconds, then record the thickness of the test specimen to an accuracy of 0.01 mm. Repeat this process for a total of ten test specimens. Calculate the thickness at 7 g / cm³. 2 The arithmetic mean of all thickness measurements obtained under the confining pressure is reported as 7 g / cm³. 2 The thickness is accurate to 0.01mm.

[0176] In order to achieve 70g / cm 2 To measure the thickness under confining pressure, first zero the micrometer relative to a horizontal, flat reference platform. Place the test specimen on the platform, with the test position centered below the pressure foot. Gently lower the pressure foot at a rate of 3.0 mm ± 1.0 mm per second until full pressure is applied to the test specimen. Wait 5 seconds, then record the thickness of the test specimen to an accuracy of 0.01 mm. Repeat this process for a total of ten test specimens. Calculate the thickness at 70 g / cm³. 2 The arithmetic mean of all thickness measurements obtained under confining pressure is reported as 70 g / cm³. 2 The thickness is accurate to 0.01mm.

[0177] Width, Length, and Area Measurement Method

[0178] Simple dimensions, such as width, length, and area, are measured at a specified location (described herein) on the surface of the absorbent article sample (or a prepared test specimen for a given area) using an image acquired using a flatbed scanner. The scanner is capable of scanning in reflective mode at a resolution of 2400 dpi and 8-bit grayscale. A suitable scanner is the Epson Perfection V750 Pro, or equivalent, from Epson America Inc., Long Beach, CA. The scanner interacts with a computer running an image analysis program. A suitable program is ImageJ v. 1.52, National Institute of Health, USA, or equivalent. The sample images are distance-calibrated against a ruler image acquired by NIST. For maximum contrast, the specimen is backed against an opaque, uniformly colored black background before image acquisition. All tests are performed in a conditioning chamber maintained at approximately 23 ± 2°C and approximately 50 ± 2% relative humidity.

[0179] Each test sample was prepared as follows. The absorbent article was removed from any existing packaging paper. If the article was folded, it was gently unfolded and any wrinkles were smoothed out. If wings were present, they were extended, but the release paper remained intact. Five complete duplicate test samples were prepared in a similar manner. Before testing, the test samples were conditioned for 2 hours at a temperature of approximately 23°C ± 2°C and a relative humidity of approximately 50% ± 2%. Note that the area of ​​the test specimens prepared as specified in the basis section of the methods for absorbent article thickness, basis weight, and density described herein was also measured using this imaging technique, and no further preparation of those test specimens was required.

[0180] Obtain the image as follows. Place the ruler on the scanning bed, oriented parallel to the side of the scanner glass. Acquire an image of the ruler (calibration image) in reflective mode at a resolution of 2400 dpi (approximately 94 pixels / mm) and 8-bit grayscale. Save the calibration image as an uncompressed TIFF file. After obtaining the calibration image, remove the ruler from the scanner glass and scan the test sample or test specimen as follows. Place the test sample or prepared test specimen in the center of the scanner glass and hold it (if necessary) so that it is flat, with the body-facing surface of the test sample or prepared test specimen facing the scanner glass surface. Orient the test sample or prepared test specimen such that the entire test sample or prepared test specimen is within the glass surface. Place a black background on top of the test sample or prepared test specimen, close the scanner cover, and acquire a scan image of the entire test sample or prepared test specimen using the same settings as for the calibration image. Save the image of the test sample or prepared test specimen as an uncompressed TIFF file.

[0181] Analyze the test sample image to measure width and length as follows. Open the calibration image file in the image analysis program and use the imaging ruler to calibrate the image resolution to determine the number of pixels per millimeter. Now open the test sample image in the image analysis program and set the distance scale using the image resolution determined from the calibration image. Perform linear measurements using the line measurement tool within the image analysis software. Figure 2 and Figure 4 The widths WS, W1, W2, and W3, and the lengths LC and LT, are depicted as measured using the locations of each dimension as specified herein. A total of five replicate test samples were imaged and analyzed in a similar manner, and each linear parameter was recorded to an accuracy of 0.1 mm. The arithmetic mean of each linear parameter was calculated across the five replicate test samples and recorded as WS, W1, W2, W3, LC, and LT, to an accuracy of 0.1 mm.

[0182] The following images show the test specimen images of the central and outer absorption regions. Open the calibration image file in the image analysis program and use the imaging ruler to calibrate the image resolution to determine the number of pixels per millimeter. Now open the test specimen image in the image analysis program and set the distance scale using the image resolution determined from the calibration image. Use the freehand selection tool or equivalent within the image analysis software to draw a shape extending along the outer perimeter of the prepared test specimen to perform area measurement. Now measure the area of ​​the drawn shape and record it as the area, accurate to 0.01 mm. 2 This area is designated as either the central absorption area or the outer absorption area, and also indicates the corresponding sample number. This is repeated in a similar manner until the area of ​​each of the five replicate test specimens from each area (central and outer absorption areas) is measured and recorded, with each replicate indicating the corresponding sample number. Now, let's return to the basis section of the methods for measuring the thickness, basis weight, and density of absorbent articles.

[0183] Absorbent Article Thickness, Basis Weight, and Density Method

[0184] The thickness, basis weight, and density methods specify how to measure these parameters at two different test locations on an absorbent article sample. See also Figure 2 The test locations included the central absorption area 306 and the outer absorption area 325. All tests were conducted in a room controlled at 23℃±3℃ and 50%±2% relative humidity.

[0185] Prior to testing, condition the absorbent product test samples at 23°C ± 3°C and 50% ± 2% relative humidity for two hours. Remove the test sample from its outer packaging and then remove the protective cover / release paper from the underwear fastener on the garment-facing side of the sample. Lightly sprinkle talcum powder onto the underwear fastener to reduce any stickiness. Prepare a total of five duplicate test samples in a similar manner. Label the test samples sequentially as Sample 1 to Sample 5 by marking small numbers on the backing / garment side of each sample.

[0186] Absorbent Article Thickness

[0187] The thickness (Caliper) (or “thickness”) is measured at a designated test location on the absorbent sample using a manually operated micrometer equipped with a 7 g / cm² pressure. 2 The pressure foot provides stable pressure. This manually operated micrometer is a heavy-duty instrument with readings accurate to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic from VWR International, or an equivalent. The pressure foot is a flat, circular, movable surface with a diameter not exceeding 25.4 mm. The test sample is supported by a horizontal, flat reference platform that is larger than and parallel to the surface of the pressure foot. Zero the micrometer against the horizontal, flat reference platform. Place the test sample on the platform, with the test position centered below the pressure foot. Manually press the micrometer with 3... + The pressure foot is lowered at a descent rate of 1 mm / s until the full weight of the pressure is applied to the sample. After 5 seconds, the thickness is recorded as the absorbent article thickness, accurate to 0.01 mm, the test location is indicated as either the central absorbent area or the outer absorbent area, and the sample number is also indicated as previously labeled. As specified, the thickness is measured at three separate non-overlapping areas within the central absorbent area 306 of each intact absorbent article sample. The arithmetic mean of the thickness values ​​collected across the central absorbent areas 306 of all five replicate samples is calculated and reported as the absorbent article thickness in the central absorbent area, accurate to 0.01 mm. Now the thickness is measured at three separate non-overlapping areas within the outer absorbent area 325 of each intact absorbent article sample. The arithmetic mean of the thickness values ​​collected across the outer absorbent areas 325 of all five replicate samples is calculated and reported as the absorbent article thickness in the outer absorbent area, accurate to 0.01 mm. Additional calculations are now performed to compare the thickness of the central absorbent area with the thickness of the outer absorbent area. Using the reported arithmetic mean, subtract the thickness of the absorbent article in the outer zone from the thickness of the absorbent article in the central absorption zone, then divide by the thickness of the absorbent article in the outer absorption zone and multiply by one hundred, and report as the thickness increase %, accurate to 0.1%. Basis weight measurements were performed using the same prepared and numbered test samples.

[0188] Absorbent Article Basis Weight

[0189] The basis weight of the central absorber region 306 and the outer absorber region 325 of each prepared test sample was measured using a specially manufactured cutting die. A first cutting die with a precise shape for the outer absorber region was prepared, such that the cutting line of the die was precisely aligned with the periphery of the entire area designated as the outer absorber region 325. Figure 2 As depicted. A second cutting die with a precise shape of a central absorption area is prepared, such that the cutting line of the die is precisely aligned with the periphery of the entire area designated as the central absorption area 306, as shown. Figure 2 As depicted. It should be understood that a set of specially processed cutting dies must be prepared for each unique product design and for each different product size. The mass of the central absorbent area 306 and the outer absorbent area 325 on the test sample is measured as follows. Align the specially processed first cutting die with the periphery of the outer absorbent 325 and stamp out a first test sample including both the outer absorbent area and the central absorbent area. Now align the specially prepared second cutting die with the periphery of the central absorbent area 306 on the first test sample and stamp out a second test sample including only the central absorbent area 306, where the remainder of the first test sample now includes only the outer absorbent area 325. Mark the corresponding sample number on the backing / clothing side of each of these prepared test samples. The test samples need to be handled with care to prevent the loss of any particles or material fibers contained within each test sample. Record the mass of the sample as the central absorbent area, and record it as the mass of the central absorbent area of ​​the absorbent product, accurate to 0.001g, also indicating the sample number. Now record the mass of the sample as the outer absorbent area, and record it as the mass of the outer absorbent area of ​​the absorbent product, accurate to 0.001g, also indicating the sample number. Similarly, the remaining four repeat test samples were stamped with central and outer absorption regions, each labeled with a corresponding sample number. The mass of each region was recorded to an accuracy of 0.001 g, designating it as either the central or outer absorption region of the absorbent article, and also indicating the corresponding sample number. Width, length, and area measurements were then performed as described herein to measure the area of ​​each of the test specimens representing the central and outer absorption regions of the absorbent article. After obtaining the area of ​​each region, the basis weight was calculated by dividing the mass (g) by the area (converted to square meters) and recorded as the absorbent article basis weight, accurate to 0.1 g / m². 2 This area is designated as either the central absorption region or the outer absorption region, and also indicates the corresponding sample number. The arithmetic mean of the basis weights of all five test samples in the central absorption region is calculated and reported as the basis weight of the absorbent product in the central absorption region, accurate to 0.1 g / m³. 2Calculate the arithmetic mean of the basis weights in all five test replicates of the external absorbent region and report it as the basis weight of the absorbed article in the external absorbent region, accurate to 0.1 g / m³. 2 All these prepared test specimens, including those from the central and outer absorption regions of the absorbent article, are retained because they will be used for the basis weight method of the inner core layer, as described herein.

[0190] Absorbent Article Density

[0191] The densities of the central absorption region 306 and the outer absorption region 325 are calculated as follows. For the test sample of the central absorption region obtained from sample 1, the basis weight (g / m³) is calculated. 2 (Base weight of absorbent product, central absorption area, sample 1) divided by the thickness (mm) (thickness of absorbent product, central absorption area, sample 1), then divide the quotient by 1000 and record it as the absorbent product density of the central absorption area, accurate to 0.001 g / m³. 3 Similarly, calculate the density of the central absorption region for all five replicate test specimens. Now calculate the arithmetic mean of the densities for all five test specimens in the central absorption region and report it as the absorbent article density of the central absorption region, accurate to 0.001 g / m³. 3 For the test specimen obtained from the external absorption region of sample 1, the basis weight (g / m 2 (Base weight of absorbent product, outer absorbent area, sample 1) divided by the thickness (mm) (thickness of absorbent product, outer absorbent area, sample 1), then the quotient is divided by 1000 and recorded as the absorbent product density of the outer absorbent area, accurate to 0.001 g / m³. 3 Similarly, calculate the density of the outer absorption region for all five repeated test specimens. Now calculate the arithmetic mean of the densities for all five test specimens in the outer absorption region and report it as the absorbent article density of the outer absorption region, accurate to 0.001 g / m³. 3 .

[0192] Inner Core Layer Basis Weight

[0193] The basis weight of the inner core layer at points in the central and outer absorption zones is usually known to the manufacturer from the product manufacturing specifications. However, if the basis weight of a given article is unknown, it can be measured as follows.

[0194] For each retained absorbent article test specimen prepared in the basis weight section of the absorbent article thickness, basis weight, and density method as described herein, the basis weight of the inner core layer within the central absorbent region 306 and the outer absorbent region 325 is measured, respectively. Five absorbent article test specimens (labeled Samples 1 to 5) will exist as the central absorbent region, and five absorbent article test specimens (also labeled Samples 1 to 5) will exist as the outer absorbent region. It should be noted that the measured area values ​​of each test specimen previously recorded for calculating the basis weight of the central and outer absorbent regions of the absorbent article in the basis weight section of the absorbent article thickness, basis weight, and density method will also be used to calculate the basis weight of the inner core layer from each of these regions.

[0195] Remove the inner core layer from the test specimen, record its mass, and calculate the basis weight as follows. Begin with the absorbent article test specimen from the central absorbent region of Sample 1. Carefully remove the top sheet, bottom film, upper nonwoven layer, and lower nonwoven layer from the inner core layer of the test specimen, ensuring that no particles or fibers are lost from the inner core layer during this process. It should be understood that, depending on the unique structure of the absorbent article, additional layers may need to be removed from the absorbent article test specimen to obtain a final test specimen consisting only of the inner core layer. Record the mass of the inner core layer test specimen, accurate to 0.001 g, representing the central absorbent region, Sample 1. Divide the mass of the inner core layer from the central absorbent region of Sample 1 by the area of ​​the central absorbent region of the absorbent article of Sample 1 (previously measured), and record this as the basis weight of the inner core layer, representing the central absorbent region, Sample 1, accurate to 0.1 g / m². 2 Similarly, repeat the procedure for each of the five test specimens from samples 1 to 5 of the central absorber region until the basis weight of the inner core layer from the central absorber region is measured and recorded. Calculate the arithmetic mean of the basis weight values ​​obtained for all five central absorber region replicates and report it as the basis weight of the inner core layer of the central absorber region, accurate to 0.1 g / m³. 2 Similarly, the entire procedure was repeated for five absorbent article test specimens from the outer absorbent regions of samples 1 to 5, and the arithmetic mean of the five basis weight values ​​was calculated and reported as the basis weight of the inner core layer of the outer absorbent region, accurate to 0.1 g / m³. 2 .

[0196] Air Permeability Method

[0197] Air permeability is the velocity of airflow perpendicularly through a test specimen under specified conditions of test area, pressure drop, and time. According to pharmacopoeia method NWSP 70.1.R0 (15), using a 5cm... 2The air permeability was measured using a test head with a test area and a pressure drop of 125 Pa, employing the testing apparatus described in this method. A suitable instrument was the Textest AG FX3300 air permeability tester or an equivalent, purchased from Schwerzenbach, Switzerland. All measurements were performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, with the test samples conditioned in this environment for at least 2 hours prior to testing.

[0198] Test specimens are taken from rolls or sheets of raw material or from layers of material removed from the absorbent article. When removing the material layer from the absorbent article, care is taken not to contaminate or deform the layer during the process. The removed layer should be free of residual adhesive and any fibers that may have transferred from the underlying layer. To ensure the removal of all adhesive and any transferred fibers, the layer is immersed in a suitable solvent that will dissolve the adhesive and release any transferred fibers present without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly in a manner that prevents excessive stretching or other deformation of the material. After the material has dried, the test specimens are obtained. The test specimens must be larger than the clamping area of ​​the test head to ensure a proper seal; therefore, they will have a width and length of at least 6.5 cm. Ten test specimens are prepared in a similar manner.

[0199] The pressure drop was measured at 125 Pa with a 5 cm pressure. 2 The air permeability of the test specimen at the orifice was measured and recorded, accurate to 1 mm. 3 / mm 2 / min. Repeat this process for a total of ten replicate samples. Calculate and report the arithmetic mean of the air permeability values ​​collected from all ten replicate test samples, accurate to 1 mm. 3 / mm 2 / min.

[0200] Circular Bend Method

[0201] The circular bending method uses a universal constant-speed extension test frame to measure the force required for a plunger to push a flat fabric test specimen through an orifice in the platform. This simultaneous, multi-directional deformation of the fabric test specimen is an indicator of the fabric's stiffness or resistance to bending. All measurements were performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, with the test specimens conditioned in this environment for at least 2 hours prior to testing.

[0202] A suitable universal constant-speed extension test frame is an MTS Alliance or equivalent that interfaces with a computer running TestSuite control software (purchased from MTS Systems Corp., Eden Prairie, MN). The universal test frame is equipped with a load sensor, and the force being measured is within 1% to 99% of the load sensor's limits. Figure 16A and Figure 16B The depicted bottom fixing fixture consists of a horizontally smooth-polished stainless steel platform 2001, measuring 102.0 mm wide × 102.0 mm long × 6.35 mm thick. The platform has an orifice 2002 with a diameter of 18.75 mm at its center. The overlapping edge 2003 of the orifice should form a 45-degree angle with a depth of 4.75 mm. The platform 2001 has an adapter 2004 compatible with the platform of a universal test frame, capable of fixing the platform 2001 horizontally and orthogonally to the pulling direction of the universal test frame. There is a clearance of at least 20 mm between the lower surface of the platform and the adapter 2004 mounted to the test frame. The upper movable fixture is a cylindrical plunger 2005 with an overall length of 70 mm and a diameter of 6.25 mm. The contact end 2006 is a spherical nose with a radius of 2.97 mm. The plunger 2005 has an adapter 2007 that is compatible with the stage on the load sensor and can fix the plunger 2005 orthogonally to the platform 2001 in a way that makes it concentric with the orifice 2002 and with equal clearance on all sides.

[0203] Test specimens taken from raw material rolls or sheets, or from material layers removed from absorbent articles, are measured. When removing material layers from absorbent articles, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive and any fibers that may have transferred from the underlying layer. To ensure the removal of all adhesive and any transferred fibers, the layer is immersed in a suitable solvent that will dissolve the adhesive and release any transferred fibers present without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly to prevent excessive stretching or other deformation of the material. Once the material is dry, the test specimens are cut to the following dimensions: 37.5 mm long (parallel to the transverse axis, or the intended transverse axis of the article) and 37.5 mm wide (parallel to the longitudinal axis, or the intended longitudinal axis of the article). Five duplicate test specimens are prepared in a similar manner.

[0204] The gauge length from the bottom edge (far end) of the contact end 2006 of the plunger 2005 to the bottom surface of the platform 2001 is set to 15.0 mm. The general-purpose test frame is programmed for compression testing, lowering the chuck by 15.0 mm at 50.0 cm / min and continuously recording force (gf) and displacement (mm) at a data acquisition rate of 100 Hz, then returning the chuck to its original gauge length. To perform the test, the prepared test specimen is placed on the surface of the platform 2001, centered above the orifice 2002 and thus below the contact end 2006 of the plunger 2005. The test is started, and force (gram-force; gf) and displacement (mm) data are continuously collected. A force (gf) versus displacement (mm) graph is plotted. The peak force is recorded from the graph, accurate to 0.1 gf. This procedure is repeated for all five test specimens in a similar manner.

[0205] Calculate the arithmetic mean of the peak force values ​​recorded in all five repeated test specimens and report it as circular bending, accurate to 0.1 gf.

[0206] Scanning Electron Microscope Imaging

[0207] Scanning electron microscopy (SEM) is used to obtain cross-sectional images of test specimens, enabling visualization of the microstructure of the absorbent article, including the interconnectivity of layers within a specific region of interest. SEM images allow for qualitative assessments related to the type and shape of fibers (e.g., circular polymers, cellulose, etc.) present in the individual layers of the test specimen. This imaging technique can also be used to assess the location of the fibers and their proximity to adjacent layers.

[0208] Use a SEM such as the FEI Quanta 450 (purchased from FEI Company, Hillsboro, OR) or an equivalent to obtain secondary electron (SE) images. Calibrate the instrument according to the manufacturer's instructions before use to ensure accurate distance scaling.

[0209] Prior to testing, the absorbent product test sample is conditioned in a laboratory at 23°C ± 2°C and 50% ± 2% relative humidity for at least 2 hours. To analyze the cross-section of the test specimen, it is obtained by removing it from the absorbent product test sample as described below. The test specimen is taken from an area free of creases or wrinkles, taking care not to cause any contamination or deformation to the area to be analyzed. The test specimen is cut from the area of ​​the absorbent product test sample in a manner that includes a portion of both the central and outer absorbent areas, including any transition areas that may exist. The test specimen is approximately 3.5 cm wide (parallel to the transverse axis of the absorbent product test sample) × 2.0 cm long (parallel to the longitudinal axis of the absorbent product test sample). The cross-sectional surface is then pre-prepared by cutting along the width of the test specimen with a brand-new razor blade (such as a VWR single-edged industrial razor blade #9, surgical carbon steel, or equivalent). Use double-sided conductive tape (such as Cu, 3M (purchased from Electron Microscopy Sciences) or equivalent) to adhere the test specimen to the SEM stage so that the cross-section can be observed when the test specimen is tilted back 90°.

[0210] High-resolution SEM images (e.g., 6.8 megapixels) of the test specimens are obtained as follows. First, the cross-sectional surface of the test specimens is observed at low magnification (e.g., 40X; horizontal field of view approximately 5 mm) to identify the regions and layers of interest, and images are acquired. Then, the cross-sectional surface of the test specimens is observed at higher magnification (e.g., at least 150X; horizontal field of view approximately 1.4 mm, and at least 300X; horizontal field of view approximately 690 μm), and images are acquired. A sufficient number of images are obtained to represent the following regions of interest: the transition zone between the central and outer absorption regions; the proximity of the upper and lower nonwovens to the inner core layer; and the interaction between the inner core fibers and the upper and lower nonwovens. The entire imaging process is repeated for a total of three duplicate test specimens in a similar manner to ensure a comprehensive representation of the microstructure of the absorbent article test specimens.

[0211] In addition to the qualitative assessments achieved through image acquisition, simple quantitative measurements can be performed using image analysis software (e.g., the built-in software of SEM instruments, or standalone software such as ImageJ v. 1.52 (National Institute of Health, USA), or equivalents). Quantitative measurements, such as slice height, width, thickness, area of ​​the region of interest, and even the angle of the region, can be performed using any suitable image analysis software.

[0212] Micro-CT Measurement Method

[0213] Micro-CT measurements are used to obtain images of cross-sections of test specimens, enabling visualization of the microstructure of the absorbent article, including the interconnectivity of layers within a specific region of interest. These images allow for qualitative and quantitative assessments related to the proximity of adjacent layers within the test specimen and the resulting dimensions and shapes of designated areas within the specimen. This method is based on the analysis of 3D X-ray images of the sample obtained on a micro-CT instrument (a suitable instrument is the ScancoμCT 50, or equivalent, from Scanco Medical AG, Switzerland). The micro-CT instrument is a cone-beam photomicroscope with a shielded enclosure. A maintenance-free X-ray tube is used as the light source with an adjustable diameter focus. The X-ray beam passes through the sample, with some of the X-rays attenuated by the sample. The degree of attenuation is related to the mass of material the X-rays must pass through. The transmitted X-rays continue to strike a digital detector array and produce a 2D projected image of the sample. A 3D image of the sample is generated by collecting several individual projected images of the sample as it rotates, and then reconstructed into a single 3D image. The instrument connects to a computer running software to control image acquisition and reconstruct 3D images from raw data. The 3D images are then analyzed using image analysis software (suitable options include MATLAB from The Mathworks, Inc., Natick, MA, and Avizo 2022.2 from Visualization Sciences Group / FEI Company, Burlington, MA, or equivalent) to identify designated areas of the test specimen, measure the distance between individual layers and areas, the thickness of the areas, and any angles that occur when transitioning from one area to another within the test specimen.

[0214] Sample Preparation :

[0215] The test specimen is cut from the test sample using a very sharp blade. The specimen is taken from an area free of creases or wrinkles, taking care not to contaminate or deform it during preparation. The specimen is cut from the area of ​​the test sample in a manner that includes a portion of both the central and outer absorption areas, including any transition zones that may exist. The diameter of the test specimen is approximately 90 mm. Three duplicate test specimens are prepared from three different test samples in a similar manner. Before testing, the test specimens are conditioned at approximately 23°C ± 2°C and approximately 50% ± 2% relative humidity for 2 hours.

[0216] Image Acquisition :

[0217] Set up and calibrate the micro-CT instrument according to the manufacturer's instructions. Place the test specimen on low-density foam and position it in the appropriate holder. This allows the test specimen to be placed horizontally and scanned with minimal attenuation from any surrounding material. Collect a single 3D dataset of consecutive 13µm (micrometer) isotropic voxels. The 3D dataset has a dimension of 96.7 mm on each side in the XY plane and a sufficient number of slices to fully encompass the entire Z direction of the test specimen. Acquire images using a 70 keV and 114 μA light source without additional low-energy filters. These current and voltage settings can be optimized to produce maximum contrast in the projected data, where sufficient X-rays penetrate the test specimen, but once optimized, they remain constant for all substantially similar test specimens. Obtain a total of 3000 projected images with a total integration time of 500 ms and 4 averages for each projection. Reconstruct the projected images into a 3D dataset with 13µm (micrometer) isotropic spatial resolution and store it in 16-bit RAW format to preserve the complete detector output signal for analysis. For optimal visualization purposes, the data was scaled to 8 bits using a scaling factor of 0.4 and then resampled to a 26-micron resolution.

[0218] Image Processing :

[0219] The 3D dataset was loaded into image analysis software and cropped (trimmed) into a rectangular prism 3D image of the analysis area by removing surrounding grippers and low-density mounting material. Cropping was performed to retain the largest amount of test specimens in the analysis area within the 3D image and to minimize the blank space above and below the test specimens. Within the 3D image, every 10 cross-sectional slices were averaged together to produce less noise. This averaging resulted in thicker slices, representing a 260-micrometer thick slice along the viewing direction. The in-plane resolution was 26 micrometers.

[0220] The 3D image is oriented such that the upper surface (top sheet or the main body size of the test specimen) is as close as possible to parallel to the XY plane. Qualitative observations can now be made of the proximity of adjacent layers present in the test specimen, including the interconnectivity between said layers and the overall shape of the individual regions present (i.e., the central absorbing region and the outer absorbing region, and the transitions between said regions). In addition to qualitative observations, simple quantitative measurements (e.g., region thickness, distance between regions, angles formed when one region transitions to another, etc.) can be performed using measurement tools available within the image analysis software.

[0221] Examples / Data

[0222] The following data and examples (including comparative examples) are provided to help illustrate the upper and lower nonwoven layers and / or absorbent articles described herein. The illustrative structures are given for purposes of illustration only and should not be construed as limiting the scope of this disclosure, as many variations are possible without departing from the spirit and scope of the invention.

[0223] Nonwoven Layer Material Testing

[0224] A series of measurements were performed on the nonwoven material to evaluate its ability to be used as an upper and / or lower nonwoven layer in the absorbent core structure described herein. Samples A through G are embodiments according to this disclosure. Comparative sample H is a comparative embodiment. Samples A through G and comparative sample H are described in Table 1 below.

[0225] Samples A to G and comparative sample H were evaluated using the CD cyclic elongation to 3% strain method, fracture strain method, dry CD ultrasensitive 3-point bending method, and nonwoven thickness-pressure method. The results are shown in Table 2.

[0226] Table 1 : Nonwoven Material Descriptions

[0227]

[0228] 1 Purchased ATB Z87G-40 from Xiamen Yanjan New Material Co. (China)

[0229] 2 With Sawasoft ® 53FC041001 was purchased from Sandler GmbH (Germany).

[0230] 3 With Sawasoft ® 553FC041005 (Option 82) was purchased from Sandler GmbH (Germany).

[0231] 4 Purchased Aura 20 from Xiamen Yanjan New Material Co. (China)

[0232] 5 Purchased from Jacob Holms Industries (Germany) under license number S25000541R01.

[0233] 6Purchased from dPFNonwovens Czech SRO (Czech Republic) with PFNZN 18G BICO8020 PHI 6.

[0234] 7 The PEGZN25 BICO7030 Phobic was purchased from dPFNonwovens Czech SRO (Czech Republic).

[0235] 8 Purchased from DunnPaper (USA) for 3028.

[0236] Table 2 :

[0237]

[0238] It is believed that nonwoven materials suitable for the upper and / or lower nonwoven layers can be strained (elongated) by balanced stretching and return to their initial state, thereby helping the absorbent core structure and / or absorbent article to recover from deformation during body movement. The 3D inner core shape described herein is constructed to fit closely to the wearer's genitals and is positioned between the labia majora. Therefore, a particularly suitable nonwoven material for the upper nonwoven layer can provide fluid handling properties, which can effectively deliver fluids deep into the inner core layer, thereby helping to provide a close and comfortable fit to the body and a dry feel. To achieve this, a suitable nonwoven material for the upper nonwoven layer exhibits a relatively low density (e.g., at 7 g / cm³). 2 The pressure is 0.03 g / cm³. 3 Up to 0.07 g / cm 3 This allows fluid to be efficiently drained from the upper nonwoven layer into the underlying core layer. Furthermore, a suitable nonwoven material for the upper nonwoven layer is required even under high body compressive forces (i.e., 70 g / cm³). 2 Even under pressure, it can maintain a relatively fluffy thickness, preventing fluid within the inner core layer from escaping from the absorbent core structure and thus avoiding a wet feeling on the body. Nonwoven materials suitable for the upper and / or lower nonwoven layers may also need to be able to conform to and present the complex 3D inner core layer shapes described herein.

[0239] Samples A through C and E were found to be suitable materials for the upper and / or lower nonwoven layers. Specifically, samples A through C and E exhibited a permanent strain of 0.013 mm / mm or less, indicating that the material can elongate and recover, and has a fracture strain greater than 10% before tearing. Samples A through C and E also required relatively low bending energy (less than 1.6 N). (proven by dry bending energy of mm), while with a value greater than 0.03N. The dry recovery energy from bending was mm. Samples A to C and E showed a recovery energy of 7 g / cm. 2 0.03 g / cm under pressure 3 Up to 0.07 g / cm 3 The relatively low density and at 7 g / cm³ 2 The thickness of these materials, ranging from 0.80 mm to 1.21 mm under pressure, demonstrates that they are porous and have a more open fiber network structure, which can contribute to effective fluid handling performance.

[0240] Sample D was found to have a permanent strain of 0.016 mm / mm, demonstrating that the material may significantly elongate during manufacturing and / or use without returning to its initial state. Therefore, it is believed that the material may not be able to maintain the structural stability and shape of the inner core. Simultaneously, Sample D was found to be highly compressible under body pressure, such as 70 g / cm³. 2 The thickness of 0.19 mm demonstrates that the material will become denser under body compression and may not adequately expel fluid through the inner core. Samples F and G exhibited less than 0.03 N. The dry recovery energy of mm demonstrates that the material does not recover from deformation, making it unsuitable for use as an upper nonwoven layer. However, samples D, F, and G are suitable materials for the lower nonwoven layer when combined with the upper nonwoven layer described herein.

[0241] Comparing sample H, it exhibits a fracture strain of less than 5% and at 70 g / cm². 2 The thickness is less than 0.2 mm. Furthermore, comparative sample H was found to tear upon wetting. Therefore, comparative sample H is insufficient for use as either an upper or lower nonwoven layer.

[0242] For the reader's convenience, Table 3 is provided. Table 3 includes an incomplete list of properties and an incomplete list of corresponding values ​​for each property that the particularly suitable upper nonwoven layer of this disclosure may exhibit.

[0243] Table 3: Upper Nonwoven Layer

[0244]

[0245] Nonwoven Material - Processability Testing

[0246] A series of measurements were performed on the nonwoven material to evaluate its bending / stretching properties and its ability to allow air to pass through (simulating whether the material can conform to the core pocket of a molded drum). Samples A, I, and J are embodiments according to this disclosure. Comparative sample K is a comparative embodiment. Samples A, I, J, and comparative sample K are described in Table 4 below.

[0247] Samples A, I, J, and comparative sample K were evaluated using the circular bending method, the CD cyclic elongation to 3% strain method, and the air permeability method. The results are shown in Table 4.

[0248] Table 4. Nonwoven Materials Tested in Circular Bend Method, CD Cycle Elongation to 3% Strain Method, and Air Permeability Method

[0249]

[0250] 1 Purchased ATB Z87G-40 from Xiamen Yanjan New Material Co. (China)

[0251] 9 With Sawasoft ® Gen1X C 53FC041001 was purchased from Sandler GmbH (Germany).

[0252] 10 With Sawasoft ® New Opt.160 was purchased from Sandler GmbH (Germany).

[0253] 11 With Sawasoft ® Option 162 (4.01682) was purchased from Sandler GmbH (Germany).

[0254] Samples A, I, and J were found to exhibit a thickness of 139 mm. 3 / mm 2 / min to 271mm 3 / mm 2 The permeability of [amount missing] g / min demonstrates that these materials will have sufficient airflow during processing to properly guide the liquid absorbent material into the core pocket within the molding drum. Furthermore, samples A, I, and J exhibit circular bending of 3.1 gf to 5.2 gf, demonstrating that these materials will be able to flex / stretch to conform to the shape of the core pocket within the molding drum in the X, Y, and Z directions, and thus be able to form the contour and shape of the inner core layer described herein. While comparative sample K exhibits sufficient permeability, this material exhibits a circular bending of 10.8 g and a tensile stiffness of 2.41 N / mm. It is believed that comparative sample K will be too stiff to conform to the shape of the core pocket within the molding drum in the X, Y, and Z directions, and therefore cannot form the contour and shape of the inner core layer described herein.

[0255] Then, nonwoven samples A, I, J and comparative sample K were used to generate absorbent core structures to evaluate the effect of the mechanical properties of the nonwoven layer material on the thickness. Examples 1 to 3 in Table 5 illustrate the absorbent core structures described herein. Comparative Example 4 is a comparative example. Descriptions of Examples 1 to 3 and Comparative Example 4 are listed in Table 5. The absorbent core structures were prepared as described below. The absorbent cores were evaluated according to the "Thickness, Basis Weight, and Density Method of Absorbent Articles" as described herein. The results are in Table 6.

[0256] Table 5: Absorbent Core Structure Descriptions

[0257]

[0258] 1 Purchased ATB Z87G-40 from Xiamen Yanjan New Material Co. (China)

[0259] 6 Purchased from PFNonwovens Czech SRO (Czech Republic) using PFNZN 18G BICO8020 PHI 6.

[0260] 9 With Sawasoft ® Gen1X C 53FC041001 was purchased from Sandler GmbH (Germany).

[0261] 10 With Sawasoft ® New Opt.160 was purchased from Sandler GmbH (Germany).

[0262] 11 With Sawasoft ® Option 162 (4.01682) was purchased from Sandler GmbH (Germany).

[0263] 12 Purchased from Stora Enzo (Sweden) using NaturaFluff.

[0264] 13 Purchased from Nippon Shokubai (Japan) as an Acqualic L705.

[0265] The absorber core structures listed in Table 5 are manufactured as detailed in the specification. Examples 1 to 3 and Comparative Example 4 have the following characteristics: Figure 4The central and outer absorption regions shown and described, wherein the basis weight of the inner core layer is as follows: Example 1 – Central absorption region: 373 gsm fluff and 145 gsm AGM; Outer absorption region: 193 gsm fluff and 75 gsm AGM; Example 2 – Central absorption region: 349 gsm fluff and 136 gsm AGM; Outer absorption region: 191 gsm fluff and 74 gsm AGM; Example 3 – Central absorption region: 371 gsm fluff and 145 gsm AGM; Outer absorption region: 189 gsm fluff and 74 gsm AGM; and Comparative Example 4 – Central absorption region: 357 gsm fluff and 138 gsm AGM, Outer absorption region: 202 gsm fluff and 78 gsm AGM.

[0266] Specifically, the upper nonwoven layer is first introduced onto the forming drum within the resting section and drawn into a three-dimensional pocket shape under vacuum. A uniform flow of cellulose and superabsorbent granular material is deposited directly onto the upper nonwoven layer within the forming station. Before entering the forming station, the upper nonwoven is coated with a spray adhesive (Technomelt DM9036U, 6 gsm continuous meltblown spiral, 50 mm wide, purchased from Henkel (Germany)) to provide a stronger bond between the cellulose and superabsorbent granular material and the upper nonwoven layer without impeding the flow of liquid into the cellulose / superabsorbent polymer matrix. Upon exiting the resting section, the lower nonwoven web is combined with the nonwoven carrying a uniform blend of cellulose and superabsorbent granular material. The lower nonwoven fabric was pre-coated with an adhesive (Technomelt DM 9036U from Henkel (Germany)) to achieve a peripheral seal (10gsm meltblown spiral, 20mm wide on the sides), and a 6gsm, 50mm wide continuous meltblown spiral adhesive (Technomelt DM 9036U from Henkel (Germany)) was applied to the center to better integrate the cellulose and superabsorbent granular materials. Excess nonwoven material extending beyond the peripheral seal was then removed.

[0267] Table 4b: Absorbent Core Structures Tested in Absorbent Article Thickness, Basis Weight, and Density Method

[0268]

[0269] Comparative Example 4 has an upper nonwoven layer with a circular bend of 10.8 gf (Comparative Sample K), even with a thickness of 384 mm. 3 / mm 2With a high air permeability of / min, the central absorbent zone cannot achieve the same thickness increase as the outer absorbent zone. As the circular curvature decreases in the upper nonwoven layer (as seen in Examples 1 to 3), a thickness increase in the central absorbent zone compared to the outer absorbent zone can be achieved, thereby allowing absorbent articles containing these absorbent core structures to fit the body more effectively.

[0270] Combinations / Examples

[0271] Paragraph A. 1. A disposable absorbent article, said disposable absorbent article comprising:

[0272] Top film;

[0273] negatives; and

[0274] An absorbent core structure disposed between the top sheet and the bottom sheet, wherein the absorbent core structure comprises:

[0275] a. An upper nonwoven layer comprising polymer fibers and having a basis weight of about 30 gsm to about 85 gsm, wherein the upper nonwoven layer comprises an upper surface and a lower surface opposite to the upper surface;

[0276] b. A lower nonwoven layer comprising polymer fibers; and

[0277] c. An inner core layer disposed between the upper nonwoven layer and the lower nonwoven layer, wherein the inner core layer comprises about 50% to about 85% of cellulose fibers by weight of the inner core layer, and about 15% to about 50% of superabsorbent particles by weight of the inner core layer.

[0278] The inner core layer further includes a central absorption region and an outer absorption region substantially surrounding the central absorption region, wherein the central absorption region has a first basis weight and the outer absorption region has a second basis weight, wherein the first basis weight is greater than the second basis weight;

[0279] The multiple cellulose fibers of the inner core layer penetrate the lower surface of the upper nonwoven layer;

[0280] The upper nonwoven layer has a circular curvature of about 2.5 gf to about 10 gf, as measured by the circular curvature method.

[0281] Paragraph B. The disposable absorbent article according to paragraph A, wherein the plurality of cellulose fibers penetrate into the upper nonwoven layer to a depth of about 0.01 mm to about 0.5 mm.

[0282] Paragraph C. The disposable absorbent article according to paragraph A or B, wherein the polymer fibers of the upper nonwoven layer have an average fiber diameter of about 2.0 dtex to about 8.0 dtex.

[0283] Paragraph D. The disposable absorbent article according to paragraphs A through C, wherein the upper nonwoven layer has approximately 100 mm 3 / mm 2 / min to approximately 500mm 3 / mm 2 / min of air permeability, as measured according to the air permeability method.

[0284] Paragraph E. The disposable absorbent article according to paragraphs A to D, wherein the central absorbent region further includes a transition region having a width of about 1 mm to about 5 mm.

[0285] Paragraph F. The disposable absorbent article according to paragraphs A through E, wherein the inner core layer is an integral structure.

[0286] Paragraph G. The disposable absorbent article according to paragraphs A through F, wherein the absorbent article has a first average density measured in the central absorbent region and a second average density measured in the outer absorbent region, wherein the first average density and the second average density are approximately 0.045 g / cm³. 3 and approximately 0.150 g / cm 3 between.

[0287] Paragraph H. The disposable absorbent article according to paragraphs A to G, wherein the absorbent article has a thickness of about 2.5 mm to about 6 mm as measured in the central absorbent region.

[0288] Paragraph I. The disposable absorbent article according to paragraphs A to H, wherein the absorbent article further includes a flexural adhesive channel region positioned between the central absorbent region and the outer absorbent region.

[0289] Paragraph J. The disposable absorbent article according to paragraph E, wherein the transition zone forms an angle of about 2 degrees to about 40 degrees with respect to the z-axis.

[0290] Paragraph K. The disposable absorbent article according to paragraphs A to J, wherein the central absorbent region includes a pair of inwardly recessed longitudinal sides, an outwardly protruding front edge, and an outwardly protruding rear edge.

[0291] Paragraph L. The disposable absorbent article according to paragraphs A to K, wherein the upper nonwoven layer includes a central region, an outer region surrounding the central region, and a transition region disposed between the central region and the outer region; wherein the multiple cellulose fibers of the inner core layer penetrate the lower surface of the upper nonwoven layer in the transition region.

[0292] Paragraph M. A disposable absorbent article according to paragraph L, wherein the multiple cellulose fibers of the inner core layer penetrate the lower surface of the upper nonwoven layer in the central region.

[0293] Paragraph N. A disposable absorbent article according to paragraphs A through M, wherein the absorbent article has a thickness increase of at least 20%.

[0294] Paragraph O. The disposable absorbent article according to paragraphs A to N, wherein the upper nonwoven portion is

[0295] The layer has a tensile stiffness of about 0.1 N / mm to about 2.2 N / mm.

[0296] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and the range surrounding its functional equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0297] Unless expressly excluded or otherwise limited, every reference cited herein, including any cross-references or related patents or applications, is incorporated herein by reference in its entirety. Reference to any reference is not an endorsement of it as prior art to any disclosed or protected art herein, nor is it an endorsement of any such invention, either on its own or in combination with any one or more references. Furthermore, where any meaning or definition of a term in this invention conflicts with any meaning or definition of the same term in referenced documents, the meaning or definition given to that term in this invention shall prevail.

[0298] While specific embodiments of the invention have been illustrated and described by way of example, it will be apparent 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. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered by the appended claims.

Claims

1. A disposable absorbent article, the disposable absorbent article comprising: The longitudinal axis, the transverse axis, and the z-axis perpendicular to the longitudinal axis and the transverse axis; Top film; negative; as well as An absorbent core structure disposed between the top sheet and the bottom sheet, wherein the absorbent core structure comprises: a. An upper nonwoven layer comprising polymer fibers and having a basis weight of about 30 gsm to about 85 gsm; b. A lower nonwoven layer comprising polymer fibers; and c. An inner core layer disposed between the upper nonwoven layer and the lower nonwoven layer, wherein the inner core layer comprises about 50% to about 85% of cellulose fibers by weight of the inner core layer, and about 15% to about 50% of superabsorbent particles by weight of the inner core layer. The inner core layer includes a central absorption region and an outer absorption region substantially surrounding the central absorption region, wherein the central absorption region has a first basis weight and the outer absorption region has a second basis weight, wherein the first basis weight is greater than the second basis weight; The central absorption region includes a transition region that forms an angle of approximately 2 degrees to approximately 40 degrees relative to the z-axis. The central absorption region includes a pair of inwardly recessed longitudinal sides, an outwardly protruding front edge, and an outwardly protruding rear edge.

2. The disposable absorbent article according to claim 1, wherein the multiple cellulose fibers of the inner core layer penetrate the lower surface of the upper nonwoven layer.

3. The disposable absorbent article according to claim 1 or claim 2, wherein the upper nonwoven layer has a circular curvature of about 2.5 gf to about 10 gf, as measured by the circular curvature method.

4. The disposable absorbent article according to any one of claims 1 to 3, wherein the plurality of cellulose fibers penetrate into the upper nonwoven layer to a depth of about 0.01 mm to about 0.5 mm.

5. The disposable absorbent article according to any one of claims 1 to 4, wherein the polymer fibers of the upper nonwoven layer have an average fiber diameter of about 2.0 dtex to about 8.0 dtex.

6. The disposable absorbent article according to any one of claims 1 to 5, wherein the upper nonwoven layer has a thickness of about 100 mm. 3 / mm 2 / min to approximately 500mm 3 / mm 2 / min of air permeability, as measured according to the air permeability method.

7. The disposable absorbent article according to any one of claims 1 to 6, wherein the central absorbent region further comprises a transition region, wherein the transition region has a width of about 1 mm to about 5 mm.

8. The disposable absorbent article according to any one of claims 1 to 7, wherein the inner core layer is an integral structure.

9. The disposable absorbent article according to any one of claims 1 to 8, wherein the absorbent article has a first average density measured in the central absorbent region and a second average density measured in the outer absorbent region, wherein the first average density and the second average density are approximately 0.045 g / cm³. 3 and approximately 0.150 g / cm 3 between.

10. The disposable absorbent article of claim 9, wherein the second density is from about 0% to about 20% of the first density.

11. The disposable absorbent article according to any one of claims 1 to 10, wherein the absorbent article has a thickness increase of at least 20%.

12. The disposable absorbent article according to any one of claims 1 to 11, wherein the absorbent article has a thickness of about 2.5 mm to about 6 mm as measured in the central absorbent region.

13. The disposable absorbent article according to any one of claims 1 to 12, wherein the absorbent article further comprises a flexural adhesive channel region positioned between the central absorbent region and the outer absorbent region.

14. The disposable absorbent article according to any one of claims 1 to 13, wherein the upper nonwoven layer has a tensile stiffness of about 0.1 N / mm to about 2.2 N / mm.

15. The disposable absorbent article according to any one of claims 1 to 14, wherein the upper nonwoven layer comprises a central region, an outer region surrounding the central region, and a transition region disposed between the central region and the outer region.

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