Absorbent article comprising an absorbent core structure having a molded inner core layer

Abstract

Disposable absorbent articles are disclosed, having a top sheet, a back sheet, and an absorbent core structure disposed between them. The absorbent core structure includes an upper nonwoven fabric layer containing polymer fibers, a lower nonwoven fabric layer containing polymer fibers, and an inner core layer disposed between them, containing cellulose fibers and superabsorbent particles. The inner core layer is contoured longitudinally and transversely and is defined by a central absorbent zone and an outer absorbent zone substantially surrounding the central absorbent zone. The basis weight of the central absorbent zone is greater than that of the outer absorbent zone. The absorbent article has a first average density measured in the central absorbent zone and a second average density measured in the outer absorbent zone. The first and second average densities are approximately 0.045 g / cm³. 3 ~Approx. 0.150g / cm 3 Therefore, the second density is within approximately 0 to 20% of the first density.

Description

[Technical Field]

[0001] This disclosure relates to an absorbent article comprising an absorbent core structure having a molded inner core layer. [Background technology]

[0002] Absorbent articles, such as diapers, training pants, women's pads, and adult incontinence pads, are widely used among consumers. Generally, these absorbent articles include a top sheet and a back sheet, with an absorbent core structure positioned between them. These absorbent articles are designed to absorb and retain fluids and other discharges from the human body to prevent soiling of the body and clothing. To effectively absorb fluids without causing leakage, absorbent articles for menstruation should conform closely to the anatomical shape of the female genitalia so that the absorbent article can capture the fluid as it exits the labia. A common complaint from current users of absorbent articles is the feeling that fluid moves along the body or leaks out of the article during heavier discharge events. In the case of products applied to panties, panties and absorbent articles often do not fit close enough to the body, failing to address these consumer concerns. Historically, absorbent articles have tried to address this problem by adding more bulk (i.e., absorbent material) to fill the space between the user's legs. Other approaches have involved adding more absorbent material to the center of the absorbent article (commonly referred to as "more in the center") to increase the caliper capacity in the central region. This is often achieved by contouring the cellulose absorbent material along its longitudinal direction, or by adding an additional, separate, elliptical absorbent layer.

[0003] However, these conventional approaches do not adequately address the problem of reducing or eliminating fluid diffusion over the body because the added absorbent material is always bulky, rigid, and not molded to fit the wearer's body structure comfortably. In the case of the female genitalia, fluid first exits the body internally within the labia minora, particularly within the labial vestibule, and then exits through the labia majora. Fluid can exit the labial structure at the apex, base, and / or sides. Because the labial vestibule is curved, a gap typically exists between the labia majora, and as a result, simply adding absorbent material to the central region does not capture the fluid exiting from the labia minora. Conventional "more in the center" shapes are located above the labial structure and therefore form a bridge across the gap between the labia majora without actually capturing the fluid that resides within the labial vestibule and moves outward from there. Furthermore, the typical bulky central region can actually push the non-bulky portions of the absorbent material away from the body, thus creating more gaps on the sides, allowing the fluid to diffuse and be felt by the consumer. [Overview of the project] [Problems that the invention aims to solve]

[0004] Therefore, there is a need for improved absorbent materials that more effectively capture fluid within the labia majora, without being rigid or bulky, as the fluid exits from the labia minora, and across the various shapes and sizes of the female genitalia. [Means for solving the problem]

[0005] This disclosure solves the problem of fluid diffusion over the body by providing an absorbent core structure having an inner core layer molded to fit snugly in and between the upper space between the labia majora, and to fit in the perineum and at the base of the pubic mound. As described herein, the absorbent article comprises an absorbent core structure with a contoured inner core layer that is highly compressible and moldable without bulk, allowing the absorbent article to comfortably conform and snugly fit to a wide range of female anatomical shapes.

[0006] A disposable absorbent article comprises a top sheet, a back sheet, and an absorbent core structure disposed between the top sheet and the back sheet, comprising: (a) an upper nonwoven fabric layer containing polymer fibers and having a basis weight of approximately 30 gsm to approximately 85 gsm; (b) a lower nonwoven fabric layer containing polymer fibers and having a basis weight of approximately 10 gsm to approximately 40 gsm; and (c) an inner core layer disposed between the upper and lower nonwoven fabric layers, wherein the inner core layer comprises approximately 50% to approximately 85% by weight of cellulose fibers and approximately 15% to approximately 50% by weight of superabsorbent particles. The absorbent core structure comprises an inner core layer, the inner core layer being contoured longitudinally and transversely, and further comprising a central absorbent zone and an outer absorbent zone substantially surrounding the central absorbent zone, the central absorbent zone having a first basis weight, and the outer absorbent zone having a second basis weight, the first basis weight being greater than the second basis weight, and the absorbent article having a first average density measured in the central absorbent zone and a second average density measured in the outer absorbent zone, the first and second average densities being approximately 0.045 g / cm³ 3 ~Approx. 0.150g / cm 3 Therefore, the second density is within approximately 0 to 20% of the first density.

[0007] A disposable absorbent article comprises a top sheet, a back sheet, and an absorbent core structure disposed between the top sheet and the back sheet, wherein the absorbent core structure comprises (a) an upper nonwoven fabric layer containing polymer fibers and having a basis weight of about 35 gsm to about 85 gsm, (b) a lower nonwoven fabric layer containing polymer fibers and having a basis weight of about 10 gsm to about 40 gsm, and (c) an inner core layer disposed between the upper nonwoven fabric layer and the lower nonwoven fabric layer, wherein the inner core layer contains a mixture of cellulose fibers and superabsorbent particles. The absorbent core structure comprises an inner core layer, the inner core layer further comprises a central absorbent zone having a first basis weight and an outer absorbent zone having a second basis weight, the outer absorbent zone substantially encloses the central absorbent zone, the first basis weight is greater than the second basis weight, the inner core layer is a single integrated structure, and the absorbent article has a first average density measured in the central absorbent zone and a second average density measured in the outer absorbent zone, the second density being within approximately 0 to approximately 20% of the first density. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of an absorbent article having one or more configurations shown and described herein. [Figure 2] Figure 1 is a plan view of the absorbent material, with the surface facing the wearer oriented towards the viewer, and a portion of the structure has been cut out to more clearly show the composition of the absorbent core structure. [Figure 3] This is a cross-sectional view of Figure 2, cut along line 3-3, with the top and back sheets removed to more clearly show the absorbent core structure. [Figure 4] This is a plan view of an exemplary absorbent article, with the surface facing the wearer facing the viewer, showing the configuration of the central absorbent zone and the outer absorbent zone in one or more configurations shown and described herein. [Figure 5] This is an enlarged view of a structural connection site formed by one or more configurations shown and described herein. [Figure 6] Figure 5 is a cross-sectional view of the structural connection site. [Figure 7A] Figure 4 is a cross-sectional view of the absorbent article taken along line 7A-7A, showing the contour of the inner core layer in the intermediate region of the absorbent article, according to one or more configurations shown and described herein. [Figure 7B] Figure 4 is a cross-sectional view of the absorbent article taken along line 7B-7B, showing the contour of the inner core layer in the rear region of the absorbent article, according to one or more configurations shown and described herein. [Figure 8] Figure 4 is a cross-sectional view of the absorbent article taken along line 8-8, showing the contour of the inner core layer in one or more configurations shown and described herein. [Figure 9] This is a plan view of an exemplary absorbent article, with the surface facing the wearer oriented towards the viewer, showing a flexible binding channel region in one or more configurations shown and described herein. [Figure 10A] This is a test method configuration for the ultra-high sensitivity three-point bending method using dry CD. [Figure 10B] This is a test method configuration for the ultra-high sensitivity three-point bending method using dry CD. [Figure 10C] This is a test method configuration for the ultra-high sensitivity three-point bending method using dry CD. [Modes for carrying out the invention]

[0009] When used in this specification, “disposable absorbent articles” or “absorbent articles” refer to articles intended for disposal after use, such as diapers, training pants, diaper pants, re-fastening pants, adult incontinence pads, adult incontinence pants, women’s hygiene pads, and cleaning pads.

[0010] As used herein, “absorbent core structure” shall be used in relation to the upper nonwoven layer, the lower nonwoven layer, and the inner core layer positioned between the upper and lower nonwoven layers. As used herein, “absorbent core structure” shall not include any secondary top sheet, top sheet, secondary back sheet, or back sheet of the absorbent article.

[0011] As used herein, “hydrophilic” and “hydrophobic” have well-established meanings in the art with respect to the water contact angle on the surface of a material. Therefore, a material with a water contact angle greater than about 90 degrees is considered hydrophobic, and a material with a water contact angle less than about 90 degrees is considered hydrophilic. A hydrophobic composition increases the water contact angle on the surface of a material, while a hydrophilic composition decreases it. Notwithstanding the foregoing, references to relative hydrophobicity or hydrophilicity between a material and a composition, 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 is greater than that of the material. As another example, 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 is smaller than that of the material.

[0012] As used herein, the term “filament” refers to any type of continuous strand produced through a spinning process, a melt-blown process, a melt-fibrillation or film-fibrillation process, or an electrospinning production process, or any other suitable process for producing a filament. The term “continuous” in the context of filament is distinguished from staple filaments, which are cut to a specific target length. In contrast, a “continuous filament” is not cut to a predetermined length, but can instead break at random lengths, though typically much longer than staple filaments.

[0013] As used herein, “machine direction” refers to the direction in which the web flows through the absorbent material processing process. For brevity, “machine direction” may be referred to as “MD.”

[0014] In this specification, "machine transverse direction" refers to the direction perpendicular to the MD. For brevity, "machine transverse direction" may be referred to as "CD".

[0015] Decitex, also known as Dtex, is a measurement used in the textile industry to measure yarn or filament. 1 decitex = 1 gram per 10,000 meters. In other words, if a yarn or filament weighs 500 grams per 10,000 linear meters, then that yarn or filament has 500 decitex.

[0016] As used herein, “elastic” refers to a material that tends to retain its shape in both dry and wet conditions, and, when subjected to a compressive force, tends to recover its original pre-compression shape when such force is removed. In some embodiments, the upper and / or lower nonwoven layers described herein may be elastic.

[0017] As used herein, “facing the wearer” (which may also be referred to as “facing the body”) and “facing the outside” (which may also be referred to as “facing the garment”) refer to the relative position of the surface of an element or group of elements, respectively. “Facing the wearer” means that the element or surface is closer to the wearer during wear than any other element or surface. “Facing the outside” means that the element or surface is further away from the wearer during wear than any other element or surface (i.e., the element or surface is closer to the wearer’s garment that may be worn over an absorbent article).

[0018] It should be understood that all maximum numerical limits given throughout this specification include all lower numerical limits as if they were explicitly stated herein. All minimum numerical limits given throughout this specification include all higher numerical limits as if they were explicitly stated herein. All numerical ranges given throughout this specification include all narrow numerical ranges that fall within such broad numerical ranges as if they were explicitly stated herein.

[0019] This disclosure relates to a disposable absorbent article comprising a top sheet, a back sheet, and an absorbent core structure having an upper nonwoven layer and a lower nonwoven layer, wherein the inner core layer includes a liquid absorbent material disposed between the upper and lower nonwoven layers. The liquid absorbent material may include a matrix (sometimes referred to herein as “fluff / AGM”) containing cellulose fibers and superabsorbent particles. The inner core layer may be housed within the nonwoven layers by substantially sealing at least the left and right regions of the upper and lower nonwoven layers with a periphery seal. In some configurations, the upper and lower nonwoven layers may be joined by a periphery seal extending around the entire periphery of the inner core layer.

[0020] The absorbent core structures described herein are configured to compress over a range of body movement and compression and to recover their original shape (dry or wet). The flexibility and / or elasticity of the absorbent core structures result in an absorbent article that comfortably conforms to the wearer's anatomical shape while efficiently managing fluid as it leaves the body. Unexpectedly, this can be achieved without typical high-density rigidity (for wet cohesion) by utilizing elastic upper and lower nonwoven fabric layers composed of elastic polymers located above and below the loosely filled liquid-absorbing material of the inner core layer. Remarkably, when the absorbent core structure is wet, it can bear structural loads and recover its shape without physically rigidifying or losing desired structural properties. While not bound by theory, it is believed that when selected elastic upper and lower nonwovens are positioned above and below the liquid-absorbing material in the inner core layer and bonded to and around the liquid-absorbing material, wet integrity / shape stability in a cellulose-rich absorbent core structure can be achieved without substantial densification and rigidity. The upper and lower nonwovens may have sufficient resilience to return the liquid-absorbing material to its original state and / or stable fiber orientation after compression. When a cellulose-rich fuzzy core is wrapped or enclosed in simple cellulose tissue or a nonwoven material with low elasticity, sufficient recovery energy may not be exhibited to restore its shape during use, especially when wet. The structural wet elastic nonwovens detailed herein may exhibit post-compression recovery energy sufficient to restore the cellulose-rich fiber matrix and may be selected to provide high compression recovery with relatively low stiffness in both dry and wet conditions. A suitable absorbent core structure is one that exhibits low compressive force (low resistance) and can recover its shape when the user periodically compresses it and releases the compressive force through various bodily movements. To achieve this, the structure should maintain sufficient recovery energy after multiple periodic compressions. Without sufficient recovery energy, the structure will remain in a compressed aggregate state with insufficient force (storage energy) to recover.

[0021] The absorbent articles described herein further comprise a contoured inner core layer having a central absorbent zone and an outer absorbent zone substantially surrounding the central absorbent zone. The central absorbent zone has a larger basis weight than the outer absorbent zone, creating a raised 3D structure in the intermediate region of the absorbent article. As described below, the shape of the inner core layer and / or the central absorbent zone is such that the central absorbent zone can fit gently into and between the upper space between the labia majora. The central absorbent zone and the outer absorbent zone are highly compressible without bulkiness and can therefore conform to a wide range of body shapes without discomfort.

[0022] An exemplary absorbent article 20 of this disclosure is shown in Figure 1. To provide a reference frame for this study, the absorbent article 20 in Figure 1 is shown with a longitudinal axis 80, a transverse axis 90, and a z-axis 95 perpendicular to the longitudinal axis 80 and the transverse axis 90. Figure 2 is a plan view of the absorbent article 20 of Figure 1, with the surface facing the wearer facing the viewer, and part of the structure has been cut out to more clearly show the configuration of the absorbent core structure 10. Figure 3 is a cross-sectional view cut along line 3-3 in Figure 2, with the top sheet 110 and back sheet 130 removed to more clearly show the absorbent core structure 10.

[0023] Referring to Figures 1 to 3, the absorbent article 20 comprises a top sheet 110, a back sheet 130, and an absorbent core structure 10 disposed between the top sheet 110 and the back 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.

[0024] The absorbent core structure 10 may comprise an upper nonwoven fabric layer 210 and a lower nonwoven fabric layer 220 (collectively referred to herein as the upper nonwoven fabric layer and the lower nonwoven fabric layer or the upper nonwoven fabric and the lower nonwoven fabric), and an inner core layer 200 disposed between the upper nonwoven fabric layer 210 and the lower nonwoven fabric layer 220. The inner core layer 200 may contain, for example, a liquid absorbent material such as cellulose fibers and superabsorbent particles. In some configurations, the liquid absorbent material may be uniformly distributed. In some configurations, the liquid absorbent material may exist discontinuously within the absorbent core structure 10 as stripes of liquid absorbent material separated from each other by, for example, individual pockets or areas without material. In some configurations, the absorbent core structure 10 may have a non-rectangular perimeter. Specifically, the absorbent core may be molded to define a taper along its width toward the intermediate region of the absorbent core structure. The absorbent core structure can conform to the shape of the wearer's inner thigh, such as an hourglass shape, an offset hourglass shape (one end wider than the opposite end and the middle section between the ends narrower), a bicycle seat shape (one end and the middle section narrower than the second end), an ellipse, or a trapezoidal shape.

[0025] The inner core layer 200 may comprise a central absorbent zone 306 extending from a front region 21 to a rear region 23 in the longitudinal direction of the absorbent article, and an outer absorbent zone 325 substantially surrounding the central absorbent zone 306. The central absorbent zone may comprise a transition zone 330 extending around the outer edge of the central absorbent zone, where the basis weight of the inner core layer gradually decreases. The inner core layer 200 may be contoured longitudinally and transversely such that the basis weight of the inner core layer is greater in the central absorbent zone 306 than in the outer absorbent zone 325.

[0026] In some configurations, the absorbent article 20 may have a structure comprising a top sheet 110, an upper nonwoven fabric layer 210, an inner core layer 200, a lower nonwoven fabric layer 220, and a back sheet 130 (from the surface facing the wearer to the surface facing the outside). In some embodiments, the top sheet 110 may be in direct contact with the upper nonwoven fabric layer 210, the upper nonwoven fabric 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 fabric layer 220. "Direct contact" means that there are no further intermediate component layers between each of the layers that are in direct contact. However, it is not excluded that an adhesive material may be placed between at least a portion of the above-mentioned layers.

[0027] The upper nonwoven fabric layer 210 may include a left region 210a and a right region 210b, and the lower nonwoven fabric layer 220 may include a left region 220a and a right region 220b. The upper nonwoven fabric layer 210 and the lower nonwoven fabric layer 220 may extend outward from the periphery 200a of the inner core layer and may be joined together using adhesives or other conventional bonding methods, including but not limited to ultrasonic bonding, melt bonding, crimping, and combinations thereof, to form a periphery seal 230. In some configurations, the entire inner core layer 200 may be located inside the periphery seal 230. The periphery seal 230 may help seal the liquid absorbent material of the inner core layer 200 to the inside of the upper nonwoven fabric layer 210 and the lower nonwoven fabric layer 220. The periphery seal 230 may comprise at least a first transverse seal region 231 and a second transverse seal region 231'. In some configurations, the periphery seal 230 may further comprise a front periphery seal region 232 and / or a rear periphery seal region 233. In some configurations, the periphery seal 230 may extend around the entire periphery 200a of the inner core layer. In some configurations, the periphery seal 230 may extend partially around the periphery 200a of the inner core layer.

[0028] In some configurations, the inner core layer 200 may be housed within the upper nonwoven layer 210 and the lower nonwoven layer 220 by substantially sealing at least 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 may be housed 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. Although not bound by theory, elastic nonwoven layers containing polymer fibers may retain their shape when wet and resist plasticization when attached to the inner core layer through the application of a core structure adhesive applied directly to either the inner core layer or the elastic nonwoven layer via a conventional spray coating application selected to achieve bonding but not to obstruct fluid flow to the inner core layer. The periphery seal 230 may be located in at least the intermediate region 22 of the absorbent article 20 and / or absorbent core structure 10. The intermediate region 22 (located between the wearer's thighs during use) is considered to be the area that will experience the most frequent and / or highest forces during use. It has been found that the presence of at least a portion of the periphery seal in the left and right regions of the upper and lower nonwoven fabric layers outside the inner core layer can ensure that the upper and lower nonwoven fabrics maintain their structural function without separating during physical deformation, and can help limit potential integrity and clustering problems. In addition, the periphery seal may allow any excess nonwoven fabric material to be removed in order to allow the absorbent core structure to be molded to the shape of the inner thigh.

[0029] The periphery seal 230 may have a seal width WS of approximately 1 mm to 10 mm, or approximately 2 mm to 8 mm, or approximately 3 mm to 6 mm. The seal width WS may be uniform or vary around the inner core layer. In some configurations, the absorbent article 20 may also include a front end seal 234 located in the front region 21 of the absorbent article and a rear end seal 235 located in the rear region 23 of the absorbent article. The front end seal 234 and / or the rear end seal 235 may seal the top sheet, upper nonwoven layer, lower nonwoven layer, and back sheet together. In some configurations, the front end seal 234 and / or the rear end seal 235 may seal the top sheet and the back sheet. In some configurations, the front end seal 234 and / or the rear end seal 235 may be pressure seals.

[0030] In some configurations, the upper nonwoven layer 210 and the lower nonwoven layer 220 may be cut to approximately the size and shape of the inner core layer 200 to fit between the top sheet 110 and the back sheet 130, but may be made of separate materials and may not substantially extend to either the front end seal 234 or the rear end seal 235. In some configurations, the inner core layer 200, the upper nonwoven layer 210, and / or the lower nonwoven layer 220 may be molded, 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 end seal 234 and the rear end seal 235 to the rear edge of the absorbent article.

[0031] As shown in Figure 2, the absorbent article 20 may further comprise a chassis 100 comprising an absorbent core structure 10. The absorbent core structure 10 and / or inner core layer 200 may be molded. The side edges 120 and 125 of the absorbent article 20 may follow the overall contour of the absorbent core structure 10 and / or inner core layer 200. Thus, for example, if the absorbent core structure 10 has an hourglass shape, the side edges 120, 125 of the absorbent article 20 may similarly be arranged in an hourglass shape. However, there may also be configurations in which the side edges 120 and 125 are generally straight or slightly curved so as not to follow the contour of the absorbent core structure. In some configurations, the absorbent article 20 may be symmetrical with respect to the longitudinal centerline 80 or asymmetrical with respect to the longitudinal centerline 80. Similarly, the absorbent article 20 may be symmetrical with respect to the transverse centerline 90 or asymmetrical with respect to the transverse centerline 90.

[0032] As described above, the absorbent article 20 may comprise an inner core layer 200 having a contour distribution of liquid absorbent material in the longitudinal and transverse directions. Figure 4 is a plan view of the absorbent article 20, showing the size and shape characteristics of the inner core layer 200. The inner core layer 200 may comprise a central absorbent zone 306 having a first basis weight and an outer absorbent zone 325 having a second basis weight. The outer absorbent zone 325 substantially surrounds the central absorbent zone 306. The first basis weight of the central absorbent zone 306 may be greater than the second basis weight of the outer absorbent zone 325. In some configurations, the first and second basis weights 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, when measured according to the inner core layer basis weight method. The second basis weight, when measured according to the inner core layer basis weight method, may be approximately 150 gsm to 320 gsm, or approximately 200 gsm to 300 gsm.

[0033] It should be understood that the increase in basis weight in the central absorbent zone 306 is due to additional liquid absorbent material within the inner core layer 200 located in the central absorbent zone 306 relative to the outer absorbent zone 325. The inner core layer 200 described herein may be a monolithic structure. As used herein, “monolithic structure” means that the inner core layer 200 is continuous and constructed of essentially one type of material, which is essentially the same material throughout the inner core layer 200, or essentially the same combination of two or more materials. Variations in the density and concentration of the material may occur, but these are limited to those that can be obtained without incorporating regions that are formed separately and then physically joined together. For example, if the inner core layer 200 contains liquid absorbent material, such as cellulose fibers and superabsorbent polymers, the relative concentrations of superabsorbent particles and cellulose fibers may differ in different parts of the inner core layer 200. However, if it is a monolithic structure, the inner core layer 200 does not contain, for example, layers or laminates of different compositions. Similarly, variations in density or concentration of various components may occur along the longitudinal, transverse, or thickness directions of the inner core layer 200, but the inner core layer 200 should not contain regions of the same or different materials that are physically separated by regions or layers of different compositions that are formed separately and later joined together, or regions where the basis weight of the liquid absorbent material is substantially absent.

[0034] The absorbent article 20 may have various calipers in the longitudinal and transverse directions (for example, it may be contoured to have a higher caliper in the center). In some configurations, the absorbent article 20 may have a first caliper measured in the central absorbent zone 306 and a second caliper measured in the outer absorbent zone 325. In some configurations, when measured according to the absorbent article caliper, basis weight, and density method, the first caliper may be about 2.5 mm to about 6 mm, and the second caliper may be about 1.0 mm to about 3.0 mm. In some configurations, the ratio of the first caliper to the second caliper may be about 1.2 to about 2.5.

[0035] As will be described in more detail below, the inner core layer may have a non-rectangular perimeter. Specifically, the inner core layer 200 may be molded to create a 3D shape in which the liquid absorbent material in the central absorbent zone tapers towards the intermediate region along its width, resulting in a good fit in and between the upper space between the labia majora, the perineum, and the base of the pubic mound. Figure 7A is a cross-sectional view of the absorbent article 20 of Figure 4 taken along line 7A-7A, showing the size and shape characteristics of the inner core layer in the intermediate region 22 of the absorbent article. Figure 7B is a cross-sectional view of the absorbent article 20 of Figure 4 taken along line 7B-7B, showing the size and shape characteristics of the inner core layer in the posterior region 23 of the absorbent article. Figure 8 is a cross-sectional view of the absorbent article 20 of Figure 4 taken along line 8-8, showing the size and shape characteristics of the inner core layer.

[0036] As shown in Figures 7A to 8, the central absorbent zone 306 may include a transition zone 330 in which the basis weight of the inner core layer gradually decreases. The upper nonwoven fabric layer 210 does not come into contact with the lower nonwoven fabric layer 220 in the transition zone 330. This is because the liquid absorbent material of the inner core layer is positioned between them. In some configurations, the transition zone 330 may have a width (TZ) of approximately 1 mm to 5 mm, or approximately 2 mm to 3 mm. The width of the transition zone can be measured from images obtained from micro-CT and analyzed by image analysis. While not bound by theory, it is thought that a transition zone with the above widths may help create the desired 3D shape of the central absorbent zone, allowing for a snug fit to the body.

[0037] As shown in Figure 4, the central absorbent zone 306 can be molded; that is, it can be non-rectangular. The central absorbent zone 306 can be molded to gently seat in and within the lateral space between the labia majora, while gently contacting the lateral portion of the labia minora from which blood is drained (without blood penetrating into the interior between the labia minora). Suitable shapes for the central absorbent zone include, but are not limited to, an hourglass shape, an offset hourglass shape (one end wider than the other, with a narrower middle section between the two ends), or a bicycle seat shape (one end and the middle section narrower than the second end).

[0038] In some configurations, the central absorbent zone 306 may define a perimeter including a pair of inwardly concave longitudinal side edges 308a, 308b, an outwardly convex front edge 310, and an outwardly convex rear edge 312. The central absorbent zone 306 may include a front region 314 having a first width W1, a rear region 318 having a third width W3, and an intermediate region 316 positioned between them, having a second width W2. In some configurations, the second width W2 may be smaller than the first width W1 and / or the third width W3. In some configurations, the third width W3 may be larger than the first width W1 and the second width W2. The first width W1 may be approximately 20 mm to 35 mm, or approximately 22 mm to 30 mm, when measured from the outermost point of the first inwardly concave longitudinal side edge within the front region 314 to the outermost point of the second inwardly concave longitudinal side edge. The second width W2 may be approximately 10 mm to 20 mm, or approximately 12 mm to 15 mm, when measured from the innermost point of the first inwardly concave longitudinal side edge within the intermediate region 316 to the innermost point of the second inwardly concave longitudinal side edge. The third width W3 may be approximately 30 mm to 45 mm, or approximately 32 mm to 40 mm, when measured from the outermost point of the first inwardly concave longitudinal side edge within the rear region 318 to the outermost point of the second inwardly concave longitudinal side edge. In some configurations, the second width W2 is approximately 20% to 40% of the minimum width of the inner core layer.

[0039] In some configurations, the central absorbent zone 306 may have a longitudinal length LC of approximately 115 mm to approximately 200 mm, or approximately 125 mm to approximately 195 mm, when measured from the outermost point of the outwardly convex leading edge 310 to the outermost point of the outwardly convex trailing edge 312. In some configurations, the central absorbent zone 306 may have a longitudinal length LC of approximately 50% to approximately 75% of the longitudinal length LT of the inner core layer.

[0040] While not bound by theory, the shape of the central absorbent zone is thought to allow it to more effectively capture fluid within the labia majora as fluid is discharged from the labia minora, across a wide range of female genital shapes and sizes. To effectively fit and gently conform within and between the upper spaces between the labia majora, the shape of the central absorbent zone should be narrow, for example, with a width in the range of 10-20 mm, and the narrow portion should have a corresponding narrow length, for example, about 50-80 mm. In addition, the central absorbent zone should generally be concave to allow close contact with the body and prevent fluid from spreading laterally, but should be wider in both the anterior and posterior regions to gently fit the perineum, where the body's natural curves allow fluid to bypass the pad and spread to the body, and at the base of the pubic mound.

[0041] In some configurations, the outwardly convex leading edge 310 of the central absorbent zone 306 may be located at a distance of approximately 25 mm to 45 mm from the leading edge 424 of the inner core layer 200. In some configurations, the outwardly convex trailing edge 312 of the central absorbent zone 306 may be located at a distance of approximately 25 mm to 85 mm from the trailing edge 426 of the inner core layer 200.

[0042] It can also be explained that the shape of the central absorbent zone 306 tapers as it extends from the front region to the middle region of the absorbent article, and a narrow portion 350 may be defined between the inwardly concave longitudinal side edges. The narrow portion 350 of the central absorbent zone may have a width at its narrowest point, located in front of or adjacent to the lateral centerlines 91 of the first wing portion 140 and the second wing portion 150. The narrow portion 350 of the central absorbent zone 306 may be located in the middle region 22 of the absorbent article 20. The narrow portion may have a width of about 10 mm to about 20 mm. The narrow portion may have a width of about 20% to about 40% of the minimum width of the inner core layer WC.

[0043] In some configurations, the absorbent core structure 10 and / or inner core layer 200 can be molded to substantially conform to the shape of the central absorbent zone 306.

[0044] The central absorbent zone 306, the outer absorbent zone 325, and the transition zone 330 have been discussed with reference to the inner core layer 200, but the descriptions of the different zones may also apply to the absorbent article 20. The basis weight of the absorbent article in the central absorbent zone may be about 300 gsm to about 500 gsm when measured according to the absorbent article caliper, basis weight, and density method. The basis weight of the absorbent article in the outer absorbent zone may be about 200 gsm to about 400 gsm when measured according to the absorbent article caliper, basis weight, and density method.

[0045] In some configurations, the absorbent article 20 may further comprise a plurality of structural bonding sites 15, as shown in Figure 4. Figures 5 and 6 show illustrations of exemplary structural bonding sites 15. Figure 5 is an enlarged view of an exemplary structural bonding site 15. Figure 6 is a cross-sectional view of the structural bonding site 15 in Figure 5. The structural bonding sites 15 may be symmetrical and / or asymmetrical, and may be any shape, including but not limited to circular, elliptical, heart-shaped, diamond-shaped, triangular, square, star-shaped, and / or X-shaped. While the shape of the structural bonding site may be any shape, preferred shapes may be denser shapes, such as asymmetrical shapes (as opposed to simple dots). The structural bonding sites 15 may be on the absorbent article and / or on the absorbent core structure. In some configurations, the structural bonding sites are approximately 2 mm 2 ~about 5mm 2 The bonding area may be approximately 0.5% to 5%, or 0.75% to 4.5%, or 1% to 4%, of the absorbent core structure when measured according to the structural bonding site pattern spacing and area measurement method. The average distance between structural bonding sites may be approximately 10 mm to 32 mm. In some configurations, the average distance between structural bonding sites may be greater than approximately 20 mm. In some configurations, the structural bonding sites may have a maximum width of approximately 1 mm to 6 mm, approximately 1.5 mm to 5 mm, or approximately 2 mm to 4 mm. While not limited by theory, the average distance between these structural connection points and / or the size of these structural connection points are thought to help maintain the structural integrity of the absorbent core structure without creating undesirable stiffness that could impair the absorbent article's ability to conform to the body.

[0046] In some configurations, structural bonding sites may be distributed across the absorbent article and / or absorbent core structure, or they may be concentrated in each region of the absorbent article and / or absorbent core structure. In some configurations, structural bonding sites may be concentrated 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 not contain structural bonding sites substantially and may be surrounded by areas of structural bonding sites and / or embossing. In some configurations, as shown in Figure 4, the outer absorbent zone 325 may contain multiple structural bonding sites 15, and the central absorbent zone 306 may not contain structural bonding sites 15 substantially.

[0047] In some configurations, the structural bonding site 15 may bond the top sheet 110, the upper nonwoven layer 210, the absorbent core structure 10, and the lower nonwoven layer 220. In some configurations, the structural bonding site 15 may bond the upper nonwoven layer 210, the absorbent core structure 10, and the lower nonwoven layer 220. The absorbent article 20 and / or absorbent core structure 10 may comprise the upper nonwoven layer 210 and the lower nonwoven layer 220, which are closer to each other in the Z direction at the structural bonding site 15 but are not melted to each other. Since these structural bonding sites are not melted to each other, they may not be permanent in nature and may rather mix the materials within the structural bonding site. In some configurations, the structural bonding site 15 may substantially not contain melt bonding.

[0048] As shown in Figure 9, the absorbent article 20 may also comprise one or more flexible bonded channel regions 160. In some configurations, at least one flexible bonded channel region 160 may be located between the central absorbent zone 306 and the outer absorbent zone 325. In some configurations, the flexible bonded channel region 160 may be located within the transition zone 330 or within the outer absorbent zone 325. In some configurations, the flexible bonded channel region 160 may be located adjacent to the transition zone 330 within the outer absorbent zone 325. In some configurations, the flexible bonded 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 zone 330. The flexible bonded channel region 160 may be a continuous depression and / or a series of individually compressed, closely spaced embossments.

[0049] The central absorbent zone 306 and / or the outer absorbent zone 325 may each exhibit a Z-compression energy of approximately 3.0 to approximately 8.0 N.mm when measured according to the Z-compression method. In some configurations, the Z-compression energy of the central absorbent zone may be substantially the same as that of the outer absorbent zone. While not bound by theory, it is believed that having a Z-compression energy of approximately 3.0 to approximately 8.0 N.mm provides a high level of compressibility and conformability to gently fit into the available space between the upper spaces between the labia majora, or to essentially become interlabial, without discomfort or excessive bulk that could impair the ability to fit and adapt to this position without moving too deeply within the labia majora.

[0050] Absorbent articles, when measured according to the dry MD three-point bending method, have a yield of approximately 0.03 to 0.18 N / mm² in the central absorbent zone 306 and the outer absorbent zone 325. 2 , or approximately 0.03 to approximately 0.15 N / mm 2can indicate the MD flexural modulus. In some configurations, the MD flexural modulus of the central absorbent zone 306 can be substantially the same as the MD flexural modulus of the outer absorbent zone 325. Without being bound by theory, having an MD flexural modulus of about 0.03 to about 0.18 N / mm in the central absorbent zone and the outer absorbent zone 2 is thought to help provide both integrity and comfort for the narrow central absorbent zone. If the MD flexural modulus is too low, there is a risk that the material is too thin and, rather than being present within the upper portion between the labia majora, simply covers the opening and tends to buckle or bend away from the opening. If the MD modulus is too high, the ability of the narrow central absorbent zone to fit comfortably and conform within the upper space between the labia can be impaired, or the central absorbent zone may not even be able to remain within the upper space between the labia majora when the wearer goes about their daily life.

[0051] The average density of the absorbent article measured in the central absorbent zone 306 and the outer absorbent zone 325 can be about 0.045 g / cm 3 to about 0.150 g / cm 3 when measured according to the absorbent article caliper, basis weight, and density method. In some configurations, the average density of the absorbent article measured in the central absorbent zone 306 and the outer absorbent zone 325 can be substantially similar. In some configurations, the average density of the absorbent article measured in the outer absorbent zone 325 can be within about 0 to about 20%, or about 0 to about 18%, or about 0 to about 10%, or about 0 to about 5% of the average density measured in the central absorbent zone.

[0052] A suitable upper nonwoven fabric layer may have a basis weight of approximately 30 gms to approximately 85 gms, or approximately 35 gms to approximately 70 gsm, or approximately 40 gms to approximately 60 gsm. The upper nonwoven fabric layer may have a tensile stiffness of approximately 0.1 N / mm to approximately 2.2 N / mm, or approximately 0.3 N / mm to approximately 1.6 N / mm, when measured according to the CD periodic stretching method up to 3% strain. The upper nonwoven fabric layer may have a breaking strain of more than approximately 10%, or approximately 10% to approximately 50%, or approximately 20% to approximately 40%, when measured according to the breaking strain method. The upper nonwoven fabric layer may have a permanent strain of approximately 0.005 to approximately 0.013 mm / mm, or 0.005 to approximately 0.0090 mm / mm, when measured according to the CD periodic stretching method up to 3% strain. The upper nonwoven fabric layer, when measured according to the nonwoven fabric thickness-pressure method, has a thickness of approximately 0.3 mm to 1.3 mm and a pressure of 7 g / cm². 2 The thickness at the pressure, and / or approximately 0.2 mm to approximately 0.7 mm, is 70 g / cm². 2 It may have a thickness under pressure.

[0053] A suitable lower nonwoven fabric layer may have a basis weight of approximately 10 to 40 gsm, or approximately 15 to 20 gsm. The lower nonwoven fabric layer may have a tensile stiffness of approximately 0.2 N / mm to approximately 2.0 N / mm when measured according to the CD periodic stretching method up to 3% strain. The lower nonwoven fabric layer may have a fracture strain of more than approximately 10%, or approximately 10% to approximately 50%, or approximately 20% to approximately 40% when measured according to the fracture strain method. The lower nonwoven fabric layer may have a permanent strain of approximately 0.005 to approximately 0.018 mm / mm when measured according to the CD periodic stretching method up to 3% strain. The lower nonwoven fabric layer may have a thickness of approximately 0.1 mm to approximately 1.3 mm and a weight of 7 g / cm² when measured according to the nonwoven fabric thickness-pressure method. 2 It may have a thickness under pressure.

[0054] 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 (two-component 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.

[0055] A suitable upper nonwoven fabric may contain approximately 60-100% or 70-100% synthetic fibers, or approximately 0-40% or 0-30% regenerated cellulose fibers such as rayon and / or viscose.

[0056] The upper nonwoven fabric layer may contain fibers with staple lengths of approximately 10 mm or more, or approximately 25 mm or more, or approximately 10 mm to approximately 100 mm, or approximately 20 mm to approximately 75 mm, or approximately 25 mm to approximately 50 mm. The upper nonwoven fabric layer may contain fibers with fiber diameters of approximately 1.3 Dtex to approximately 10.0 Dtex, or approximately 1.3 Dtex to approximately 6.0 Dtex, or approximately 2.0 Dtex to approximately 5.0 Dtex. Although not theoretically bound, it is thought that if the fibers of the upper nonwoven fabric layer are less than approximately 1.3 Dtex, the airflow through the material during manufacturing may be insufficient.

[0057] In some configurations, the upper nonwoven layer may contain a blend of staple fibers. If the upper nonwoven layer contains a blend of staple fibers, the fiber blend preferably contains 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 contain fibers, which are a blend of staple fibers having a fiber diameter of about 2.0 Dtex to about 8.0 Dtex. While not bound by theory, fibers with an average fiber diameter of about 2.0 Dtex to about 8.0 Dtex are thought to help allow sufficient airflow through the material during the fabrication of the absorbent core structure.

[0058] The lower nonwoven layer may contain fibers having lengths of approximately 10 mm or more, or approximately 25 mm or more, or approximately 10 mm to approximately 100 mm, or approximately 20 mm to approximately 75 mm, or approximately 25 mm to approximately 50 mm. In some configurations, the lower nonwoven layer may contain continuous fibers. The lower nonwoven layer may contain fibers having fiber diameters of approximately 1.3 DTex to approximately 5.0 DTex, approximately 1.3 DTex to approximately 3.3 DTex, approximately 1.3 DTex to approximately 2.2 DTex, or approximately 2.0 DTex to approximately 10.0 DTex. In some configurations, the lower nonwoven layer may contain fibers, which are a blend of fibers having fiber diameters of approximately 0.1 DTex to approximately 6.0 DTex.

[0059] In some configurations, the upper nonwoven layer may contain a blend of fibers, at least a portion of which have a diameter of about 2.0 DTex to about 10 DTex, and the lower nonwoven layer may contain a blend of fibers, at least a portion of which have a diameter of about 1.3 DTex to about 5 DTex. In some configurations, the upper nonwoven layer may contain a blend of fibers, at least a portion of which have a diameter of about 1.3 DTex to about 2.2 DTex, and the lower nonwoven layer may contain a blend of fibers, the blend of fibers having a diameter of about 1.3 DTex to about 5 DTex.

[0060] Suitable upper and / or lower nonwoven fabric layer materials can bend and return to their original shape in response to bending forces. Thin or highly flexible materials bend easily with low peak force (load) and low bending energy. Unsuitable materials bend easily but lack sufficient recovery energy and therefore retain the deformed bent state due to insufficient recovery energy. Suitable materials have sufficient energy to restore them to their initial pre-bending state. Materials with sufficient bending recovery energy can be considered elastic upper and lower nonwoven fabric layers. Particularly suitable upper nonwoven fabric layers have a bending energy of about 0.03 N. * Over mmm, or approximately 0.03N * mm ~ approx. 1N * mm, or approximately 0.04 N * mm ~ approx. 0.5N * It may have a drying recovery energy of mm. A particularly suitable upper nonwoven fabric layer is approximately 1.6 N* Less than mm, or approximately 1.1 N * It may have a dry bending energy of less than mm.

[0061] As described above, the upper and lower nonwovens may contain polymer fibers. Polymer fibers may be included to help provide structural integrity to the upper and lower nonwovens. Polymer fibers can help increase the structural integrity of the upper and lower nonwovens in both the machine direction (MD) and the machine transverse direction (CD), thereby facilitating the web manipulation of the upper and lower nonwovens during processing for incorporation into the pad.

[0062] Polymer fibers of any suitable composition can be selected. Some examples of suitable polymer fibers include two-component fibers containing polyethylene (PE) and polyethylene terephthalate (PET) components or polyethylene terephthalate and copolyethylene terephthalate components. The components of the two-component fiber may be arranged in a sheath-core configuration, a parallel configuration, an eccentric sheath-core configuration, a trefoil configuration, or other suitable configurations. In some configurations, the polymer fibers may include two-component fibers having PE / PET components arranged in a concentric sheath-core configuration, where the polyethylene component forms the sheath.

[0063] While other materials may be useful in creating elastic structures, the stiffness of the PET core component in the sheath-core fiber configuration is considered useful in imparting elasticity to the upper and lower nonwoven fabrics. In a synergistic combination, the PE sheath component, which has a lower melting temperature than the PET core component, can be used to provide interfiber melting / fusion bonding brought about by the heat treatment of the precursor butt. This can help provide tensile strength to the web in both MD and CD. Such interfiber bonding helps reduce slippage between fibers, thereby further contributing to imparting dimensional stability and resilience to the material, even when the material is wet.

[0064] When a relatively high weight fraction of polymer fibers is included, more connections can be formed within the structure through heat treatment. However, too many connections can impart greater stiffness to the upper and lower nonwovens 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 nonwovens.

[0065] As described above, the upper and lower nonwoven fabrics may further contain polymer fibers that increase the elasticity of the upper and lower nonwoven fabrics. The elastic polymer fibers can help the upper and lower nonwoven fabrics maintain permeability and compression recovery. In some configurations, the upper and lower nonwoven fabrics may contain elastic polymer fibers having various cross-sections, e.g., circular and hollow spiral, and / or elastic fibers having various sizes.

[0066] The polymer fibers may be elastic and may be spun from any suitable thermoplastic resin, such as polypropylene (PP), polyethylene terephthalate (PET), or other suitable thermoplastic plastics known in the art. The average staple length of the elastic polymer fibers may be greater than about 10 mm, or in the range of about 20 mm to about 100 mm, about 30 mm to about 50 mm, or about 35 mm to about 50 mm. The thermoplastic polymer fibers may have any suitable structure or shape. For example, the elastic polymer fibers may be circular, or may have other shapes such as spiral, wavy ellipse, trefoil, wavy ribbon, and so on. Furthermore, the elastic polymer fibers may be solid, hollow, or multi-hollow. The elastic polymer fibers may be solid and round. In other preferred examples, the elastic polymer fibers may include polyester / co-extruded polyester fibers. Other preferred examples of elastic polymer fibers include two-component fibers such as polyethylene / polypropylene, polyethylene / polyethylene terephthalate, and polypropylene / polyethylene terephthalate two-component fibers. These two-component fibers may have a sheath / core structure.

[0067] The elastic polymer fibers may be polyethylene terephthalate (PET) fibers or other suitable non-cellulose fibers known in the art. PET fibers may be given any suitable structure or shape. For example, PET fibers may be circular, or have other shapes such as helical, wavy elliptical, trefoil, wavy ribbon, hollow helical, and so on. PET fibers may be solid, hollow, or multi-hollow. In one particular example, PET fibers may have a hollow cross-section and may have a curled or helical structure along their length. Optionally, the elastic polymer fibers may be helically crimped or flatly crimped. The elastic polymer fibers may have an average crimp value of about 4 to about 12 crimps / inch (cpi), or about 4 to about 8 cpi, or about 5 to about 7 cpi, or about 9 to about 10 cpi. Specific, non-limiting examples of elastic polymer fibers are available from Wellman, Inc. (Ireland) under trade designations H1311 and T5974. Other examples of suitable elastic polymer fibers are disclosed in U.S. Patent No. 7,767,598.

[0068] The rigid polymer fibers and elastic polymer fibers should be carefully selected. For example, the constituent polymers forming the rigid polymer fibers and elastic polymer fibers may have commonalities, but the elastic polymer fibers must be selected such that the melting points of their constituents are higher than those of the bondable components of the rigid polymer fibers. Otherwise, during heat treatment, the elastic polymer fibers may bond to the rigid polymer fibers (or vice versa), thereby forming an excessively rigid structure. To avoid this risk when the rigid polymer fibers include two-component fibers, for example, core-sheath constituent fibers with a sheath component having a relatively low melting temperature at which molten bonding occurs, the elastic polymer fibers may include only the core constituent chemicals, which may be polymers with relatively high melting temperatures.

[0069] Nonwoven fabric performance can be influenced by a combination of the selection of nonwoven fiber polymers, fiber properties, and how the fibers are arranged or connected. The choice of nonwoven fabric can affect the ability of an absorbent article to recover its shape in response to compressive, bending, and stretching forces that occur during use due to body movement. When the fibers are short (less than approximately 10 mm), the fibers are likely to rearrange irreversibly under stretching and compressive forces. Rearranging the fibers in the fiber matrix (changing their orientation / state) dissipates the tensile (stretching) or compressive force, and as a result, the energy used to influence the deformation is not available for recovery to the original shape. Longer fiber networks (typically more than approximately 10 mm but less than approximately 100 mm) can absorb the tensile / compressive forces typical of body movement along the length of the fibers and across the structure. As a result, the absorbed forces are available to restore the structure to its original state. Longer fibrous network structures composed of finer fibers (typically about 15 microns to less than 20 microns) stretch and compress more easily. As a result, the fluff / AGM structure can deform more easily (and to a greater extent), but the energy associated with these deformations is relatively small and insufficient to return the structure to its original state. Thicker fibers, such as those over about 20 microns, or about 2.0 DTex to about 10 DTex, are flexible under bodily force but provide sufficient fiber and web recovery energy to return the structure to its original state.

[0070] From a structural standpoint, the arrangement of fibers in a long-fiber network structure can affect the performance of absorbent articles containing these nonwovens. Long-fiber webs of thicker fibers are typically bulkier than conventional thin spunbond nonwoven webs, which consist of continuous fine fibers that are closely spaced and physically bonded together. By creating webs of thicker fibers arranged in a more random orientation, which can be achieved through carding, water entanglement, and needling, the fibers can be stretched and compressed, thereby allowing them to adjust their arrangement only temporarily (spaces between fibers exist for these arrangements) and to bear / store deformation forces, this energy being available to restore the structural shape.

[0071] Furthermore, thinner synthetic fibers (less than approximately 2.0 DTex), such as BiCo and PP fibers commonly found in spunbond, are densely spaced, aligned relatively parallel to each other, and tightly bonded together. Because these bonded fibers within the spunbond web are interconnected (by closely spaced point bonds), under tension (stretching), the fibers are forced to stretch at the polymer level, causing the polymer chains within the fibers to permanently rearrange. As a result, the fibers themselves remain potentially permanently stretched (permanently distorted) and can no longer return to their original state.

[0072] In some configurations, the polymer fibers in the upper nonwoven layer and the polymer fibers in the lower nonwoven layer may be different. In some configurations, the polymer fibers in the upper nonwoven layer and the polymer fibers in the lower nonwoven layer may be the same. In some configurations, the upper nonwoven layer may be a carded nonwoven fabric. In some configurations, the upper nonwoven layer may be air-through bonded or water-flow entangled. In some configurations, the upper nonwoven layer may not be a spunbond material.

[0073] Examples of suitable nonwoven materials include, but are not limited to, the following: (i) a 40gsm carded elastic nonwoven material manufactured by Yanjan China (material code; ATB Z87G-40-90), which is a carded nonwoven composed of a blend of 60% 2DTex and 40% 4DTex BiCo(PE / PET) fibers. These fibers are bonded together (ATB = "hot" air bond) to form a wet elastic network structure. Although not bound by theory, due to the presence of 4DTex BiCo fibers and the interfiber-bonded BiCo network structure, the material exhibits low permanent strain (less than approximately 0.013 mm / mm) and sufficient dry recovery energy (approximately 0.03 N) in the dry CD ultra-high sensitivity three-point bending method. * It is considered to have a length greater than 0.013 mm. (ii) A 55 gsm elastic spunlace material manufactured by Sandler Germany (material code: 53FC041001), which is a water-flow entangled nonwoven fabric produced by water-flow entanglement using a carding process (as described above for the nonwoven fabric), followed by an upward drying process (as described in U.S. Patent Publication No. 2020 / 0315873(A1)) that produces both entangled and BiCo-bonded elastic reticular structures. It contains a fiber blend of 30% 10DTex HS-PET, 50% 2.2DTex BiCo(PE / PET), and 20% 1.3DTex rayon. This material exhibits low permanent strain (less than approximately 0.013 mm / mm) and sufficient drying recovery energy (approximately 0.03 N) in a dry CD ultra-high sensitivity three-point bending method. *(iii) A water-flow entangled nonwoven fabric produced by Sandler Germany, a 50gsm elastic spunlace material (material code: 53FC041005 opt82) manufactured by water-flow entanglement through a carding process (such as the nonwoven fabric described above) and a subsequent rising drying process (such as described in U.S. Patent Publication No. 2020 / 0315873(A1)) that produces both entanglement and a BiCo-bonded elastic reticular structure. This material contains a fiber blend of 60% 5.8DTex BiCo(PE / PET), 20% 3.3DTex trefoil-shaped "structure" rayon, and 20% 1.3DTex rayon. This material exhibits low permanent strain (less than approximately 0.013 mm / mm) and sufficient drying recovery energy (approximately 0.03 N) in a dry CD ultra-high sensitivity three-point bending method. * It has a thickness of over mm. This material contains 40% rayon, which can soften when wet, but the use of structural trifoliate rayon fibers helps maintain structural stability in wet conditions.

[0074] In combination with adjusting pore size, volume, and number by selecting appropriate fiber size, basis weight, and degree of compaction, manufacturers may desire to select fiber components to obtain specific surface chemical properties, e.g., fibers with hydrophobic or hydrophilic surfaces, or blends of different fibers and / or fibers with z-directional layering or gradients. Fibers with hydrophilic surfaces tend to attract and move along the aqueous components of menstrual fluid, in a manner that facilitates suction after discharge and rapid fluid acquisition. However, at the same time, the dominance of hydrophilic fiber surfaces in the top sheet may increase the tendency of the top sheet to reacquire fluid from the absorbent components below (re-wetting), which can cause an undesirable wet feeling for the user. On the other hand, fibers with hydrophobic surfaces tend to repel the aqueous components of menstrual fluid and / or resist the movement of fluid along their surfaces, thereby resisting suction, but also resisting re-wetting. Manufacturers may desire to find the right balance when selecting constituent fibers with hydrophilic surfaces, fibers with hydrophobic surfaces, or blends and / or z-directional lamination for any particular product design, in combination with fiber size, fiber reinforcement level, and the resulting top sheet pore size, volume, and number.

[0075] The inner core layer is manufactured by the air-lay method. A flow of cellulose and superabsorbent polymer is carried by a high-speed airflow and deposited into three-dimensional pockets on a rotational molding drum with a vacuum at the bottom to draw the cellulose and superabsorbent polymer into pockets in the laydown station. These molded pockets provide the actual physical shape of the absorbent core structure. The upper nonwoven fabric may be introduced onto the molding drum first, and under vacuum, the upper nonwoven fabric is stretched into a three-dimensional pocket shape. In this case, the flow of cellulose and superabsorbent polymer material is deposited directly onto the upper nonwoven fabric layer in the molding station. Before entering the molding station, the nonwoven fabric is coated with an adhesive to more firmly bond the cellulose and superabsorbent polymer to the nonwoven fabric layer. Exiting the laydown section, the lower nonwoven fabric layer is combined with the upper nonwoven fabric layer that carries the cellulose and superabsorbent polymer layer exiting the laydown section. This underside nonwoven is pre-coated with adhesive, allowing for a periphery seal and better integration of the cellulose and superabsorbent polymer without obstructing the flow of liquids into the cellulose and superabsorbent polymer matrix. These adhesives are not shown in the diagram for simplification.

[0076] The inner core layer may contain one of a wide variety of liquid-absorbent materials widely used in disposable absorbent articles, such as crushed wood pulp, commonly known as air felt. One suitable absorbent core material is the air felt material available from Weyerhaeuser Company (Washington, USA) under code number FR516. Other suitable liquid-absorbent materials used for the absorbent core may include crepe cellulose wadding, meltblown polymers including coform, synthetic fibers such as chemically stiffened, modified, or crosslinked cellulose fibers or crimped polyester fibers, peat moss, cotton, bamboo, absorbent polymer materials, or any equivalent materials or combinations thereof.

[0077] Absorbent polymer materials for use in absorbent articles typically include water-insoluble, water-swellable, hydrogel-forming, cross-linked absorbent polymers that can absorb large amounts of liquid and retain such absorbed liquid under moderate pressure.

[0078] The absorbent polymer material for the absorbent core according to this disclosure may include superabsorbent particles, also known as “superabsorbent material” or “absorbent gelling material.” Typically, the absorbent polymer material in particulate form may be selected from polyacrylates and polyacrylate-based materials, such as partially neutralized crosslinked polyacrylates. The term “particles” refers to granules, fibers, flakes, spheres, powders, plates, and other shapes and forms known to those skilled in the art of superabsorbent particles. In some embodiments, the superabsorbent particles may be in the form of fibers, i.e., elongated needle-shaped superabsorbent particles.

[0079] In some configurations, the inner core layer may contain cellulose fibers and superabsorbent particles. The inner core layer may contain cellulose fibers in an amount of about 50% to about 85% by weight, or about 55% to about 80% by weight, or about 60% to about 75% by weight of the inner core layer. The inner core layer may contain superabsorbent particles in an amount of about 10% to about 50% by weight, or about 15% to about 50% by weight, or about 20% to about 40% by weight, or about 25% to about 35% by weight of the inner core layer. In some configurations, the inner core layer may contain cellulose fibers in an amount of about 125 gsm to about 500 gsm. In some configurations, the inner core layer may contain superabsorbent particles in an amount of about 125 gsm to about 300 gsm.

[0080] In some configurations, the inner core layer may contain approximately 50% to 85% cellulose fibers and approximately 15% to 50% superabsorbent particles.

[0081] The absorbent article 20 may be elastic and conformable, and may provide a superior in-use comfort without substantially agglomeration and / or compression. The absorbent article may be exposed to physical force and may return to its original state.

[0082] Top sheet The top sheet 110 may be formed from any suitable nonwoven web or molded film material. Referring again to the figure, the top sheet 110 is positioned adjacent to the wearer-facing surface of the absorbent article 20 and may be bonded to that surface and to the back sheet 130 by any suitable attachment or bonding method. The top sheet 110 and the back sheet 130 may be directly bonded to each other in the outer peripheral region around the absorbent core structure, or they may be indirectly bonded by directly bonding to the wearer-facing surface and the outer-facing surface of the absorbent article, or to any additional optional layer included in the absorbent article, respectively.

[0083] The absorbent article 20 may have any known or other effective top sheet 110, such as one that conforms to the wearer's skin, is soft to the touch, and is non-irritating. Preferred top sheet materials include liquid-permeable materials that are comfortable when in contact with the wearer's skin and allow discharged menstrual fluid to rapidly permeate through them. Some preferred examples of top sheet materials include laminated structures including films, nonwovens, film / nonwoven layers, film / film layers, and nonwoven / nonwoven layers.

[0084] Non-limiting examples of nonwoven web materials that may be suitable for use in forming the top sheet 110 include fibrous materials made from natural fibers, modified natural fibers, synthetic fibers, or combinations thereof. Several suitable examples are described in U.S. Patents No. 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.

[0085] The top sheet 110 may be adaptable, soft to the touch, and non-irritating to the wearer's skin. Furthermore, the top sheet 110 may be liquid permeable so that liquids (e.g., urine, menstrual blood) can easily penetrate its thickness. Some preferred examples of top sheet materials include laminated structures including films, nonwovens, film / nonwoven layers, film / film layers, and nonwoven / nonwoven layers. Other exemplary top sheet materials and designs are disclosed in U.S. Patent Applications Publications 2016 / 0129661, 2016 / 0167334, and 2016 / 0278986.

[0086] In some examples, the top sheet 110 may include tufts as described in U.S. Patents No. 8,728,049, 7,553,532, 7,172,801, 8,440,286, 7,648,752, and 7,410,683. The top sheet 20 may have a pattern of individual hair-like fibrils as described in U.S. Patent No. 7,655,176 or 7,402,723. Additional examples of preferred top sheet materials are described in U.S. Patents No. 8,614,365, 8,704,036, 6,025,535, and U.S. Patent Publication 2015 / 041640. Another preferred top sheet may be formed from a three-dimensional substrate as detailed in U.S. Patent Application Publication 2017 / 0258647. The top sheet may have one or more layers, as described in U.S. Patent Application Publications 2016 / 0167334, 2016 / 0166443, and 2017 / 0258651.

[0087] In some examples, the top sheet 110 may be formed from a spunbond web nonwoven web material comprising single-component continuous fibers, or alternatively, two-component or multi-component fibers, or a blend of single-component fibers spun from different polymer resins, or any combination thereof. The top sheet may also be a molded nonwoven top sheet, as disclosed in U.S. Patent Application Publication No. 2019 / 0380887.

[0088] To ensure that fluids in contact with the top surface (facing the wearer) of the top sheet move suitably and rapidly in the z-direction to the bottom surface (facing outward) of the top sheet, where they can be drawn into the absorbent layer, it may be important to ensure that the nonwoven web material forming the top sheet has an appropriate weight / volume density, thereby reflecting the suitable presence of pores (also called "pores") in and between the constituent fibers through which fluids can move within the nonwoven material. In some situations, a nonwoven with fibers that are too densely compacted may have an insufficient number and / or volume and / or size of pores, and the nonwoven will hinder rather than facilitate rapid downward z-direction fluid movement. On the other hand, a nonwoven with fibers that are too large and / or not compacted to provide a certain level of opacity (for the purpose of concealing fluids absorbed into the layer below) and a substantial appearance may be perceived negatively by the user.

[0089] The caliper of the top sheet material can be controlled to balance the conflicting needs of opacity and loft (requiring a higher caliper) and the limited z-direction distance through the top sheet from the wearer-facing surface to the outward-facing surface in order for the discharged fluid to reach the underlying absorbent core structure. Therefore, it may be desirable to control the production of top sheet materials to produce top sheet materials with calipers of approximately 0.20 mm to 1.0 mm, or approximately 0.25 mm to 0.80 mm, or approximately 0.30 mm to 0.60 mm.

[0090] Secondary Top Sheet (STS) In some situations, the STS layer may be included between the top sheet and the absorbent core structure, allowing the absorbent core structure to readily receive the sudden discharge of fluid, and after receiving it, to draw it up along the x and y directions and distribute it across the absorbent core structure below.

[0091] If included, the STS may be a nonwoven fiber structure that may include cellulose fibers, noncellulose fibers (e.g., fibers spun from polymer resins), or blends thereof. To accommodate the folding and lateral gathering of the absorbent article 20 and the absorbent core structure 10, the STS may be formed from a relatively flexible (i.e., relatively low bending stiffness) material, as described herein.

[0092] Several specific examples of preferred STS compositions and structures, and combinations thereof with preferred topsheet compositions and structures, are described in U.S. Patent Applications Nos. 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 Patent Applications Nos. 63 / 086610 and 63 / 086701. Additional preferred examples are described in U.S. Patent No. 9,504,613, International Publication No. 2012 / 040315, and U.S. Patent Application Publication No. 2019 / 0021917.

[0093] In some configurations, the absorbent material may not include a secondary top sheet.

[0094] Back seat The backsheet 130 can be positioned beneath or adjacent to the outward-facing surface of the absorbent core structure 10 and can be bonded to that surface by any preferred mounting method. For example, the backsheet 130 can be fixed to the absorbent core structure 10 by a uniform, continuous layer of adhesive, a patterned layer of adhesive, or an arrangement of separate lines, spirals, or dots of adhesive. Alternatively, mounting methods may include thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other preferred mounting mechanism, or a combination thereof. In other examples, it is intended that the absorbent core structure 10 is not directly bonded to the backsheet 130.

[0095] The backsheet 130 may be impermeable to or substantially impermeable to aqueous liquids (e.g., urine, menstrual fluid) and may be manufactured from a thin plastic film, although other flexible liquid-impermeable materials may also be used. As used herein, the term “flexible” refers to a material that is adaptable and readily conforms to the general shape and contours of the human body. The backsheet 130 can prevent, or at least substantially prevent, the fluid absorbed and contained within the absorbent core structure 10 from escaping from and reaching articles of the wearer’s clothing that may come into contact with the absorbent articles 20, such as underwear and other clothing. However, in some examples, the backsheet 130 may be manufactured to allow vapors to escape from the absorbent core structure 10 (i.e., the backsheet is made to be breathable), while in other examples, the backsheet 130 may be manufactured not to allow vapors to escape (i.e., it is made to be non-breathable). Thus, the backsheet 130 may include a polymer film, such as a polyethylene or polypropylene thermoplastic film. Suitable materials for the backsheet 130 are, for example, thermoplastic films having a thickness of about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mil). Any suitable backsheet known in the art may be used in conjunction with the present invention.

[0096] Some preferred examples of materials suitable for forming backsheets are described in U.S. Patents Nos. 5,885,265, 4,342,314, and 4,463,045. Suitable single-layer breathable backsheets for use herein include, for example, those described in British Patents Nos. A2184389, A2184390, and A2184391, U.S. Patents Nos. 4,591,523, 3,989,867, and 3,156,242, International Publication No. 97 / 24097, and U.S. Patents Nos. 6,623,464, 6,664,439, and 6,436,508.

[0097] The backsheet 130 may have two layers, namely a first layer comprising a vapor-permeable perforated film layer and a second layer comprising a breathable microporous film layer, as described in U.S. Patent No. 6,462,251. Other suitable examples of double or multilayer breathable backsheets for use herein include those described in U.S. Patents No. 3,881,489, No. 4,341,216, No. 4,713,068, No. 4,818,600, European Patent Application Publications No. 203821, No. 710471, No. 710472, and No. 0793952.

[0098] Other features In some configurations, the absorbent article 20 may include panty fastening components such as panty fastening adhesive or components of a hook-and-loop fastening system (such as VELCRO®).

[0099] In some configurations, the absorbent article 20 may include a panty-fastening adhesive disposed on the garment-facing side of the backsheet 130 to provide a mechanism for the user to adhere the absorbent article to the crotch area inside the underwear. The panty-fastening adhesive may include any adhesive or glue used in the art for such purposes. These adhesives are typically pressure-sensitive and maintain tackiness much lower than their application temperature. In some configurations, the panty-fastening adhesive may be a pressure-sensitive hot-melt adhesive. When the absorbent article 20 is packaged for shipment, handling, and storage before use, the panty-fastening adhesive may be covered by one or more sheets of release film or paper, thereby covering / shielding the adhesive deposit from contact with other surfaces until the user removes the release film or paper and places the absorbent article in the underwear for wear / use. The release film or paper may also function as individual packaging for the article or provide a disposal function known in the art. Any commercially available release paper or film may be used. Suitable examples include BL 30 MG-A SILOX EI / O and BL 30 MG-A SILOX 4 P / O, available from Akrosil Corporation, and M&W film available from Gronau, Germany, under code X-5432. In some configurations, the absorbent article may be packaged in a folded or tri-folded state.

[0100] In some configurations, the absorbent article 20 may include opposing wing portions 140, 150 on each side, extending laterally outward from a first longitudinal side 141 and a second longitudinal side 151 of the absorbent article. Wings are now commonly provided on women's sanitary absorbent articles. As provided, they typically have an adhesive deposit applied to their outward-facing surface (the surface is outward before the absorbent article is placed in the user's underwear and the wings are applied). The wing portions may also include the adhesive deposit as described above, so that the user can wrap the wing portions around the inner edge through the leg opening of the underwear and adhere the wing portions to the outward-facing surface / underside of the underwear in the crotch area, providing auxiliary retaining support for the absorbent article and helping to protect the underwear from soiling in close proximity to the leg edge of the underwear.

[0101] Test method Target audience For any of the following methods in which not all constituent layers of the article are tested, the layer to be tested may be separated from the layers not being tested using cryospray as necessary.

[0102] Fracture strain method The force-displacement behavior of the specimen is measured on a universal constant-speed elongation test frame equipped with a load cell in which the measured force is within 1% to 99% of the cell's limit (a suitable instrument is the MTS Alliance with TestSuite Software, available from MTS Systems Corp. (Eden Prairie, MN), or an equivalent). The specimen is subjected to tensile elongation at a constant speed (mm / sec) until fracture, and the fracture strain percentage is measured. All tests are conducted in a room controlled at 23°C ± 3°C and 50% ± 2% relative humidity, and the test specimen is conditioned in this environment for at least 2 hours prior to testing.

[0103] The fixtures used to grip the test specimens are lightweight (<80 grams) vise-type clamps having gripping surfaces of semi-cylindrical steel versus rubber-coated steel, at least 40 mm wide. The fixtures are mounted on a universal test frame and aligned horizontally and vertically to one another.

[0104] Measurements are performed on test specimens taken from raw material rolls or sheets, or from material layers excised from absorbent articles. When excising material layers from absorbent articles, care is taken to avoid any contamination or deformation of the sample layer during the process. The excised layer should not contain any residual adhesive or fibers that may have migrated from the underlying layer. To ensure that all adhesive and migrated fibers are removed, the layer is immersed in a suitable solvent that dissolves the adhesive without adversely affecting the material itself and removes all present migrated fibers. One such solvent is THF (general-purpose tetrahydrofuran, CAS 109-99-9, available from any convenient source). After solvent immersion, the material layer is air-dried completely in a manner that prevents unwanted stretching or other deformation of the material. After the material is dry, test specimens are prepared as follows: The test specimens are cut from an area of ​​the test material that does not contain folds or wrinkles. The test specimen is 100 mm long (parallel to the transverse axis of the article, or the intended transverse axis) and 25.4 mm wide (parallel to the longitudinal axis of the article, or the intended longitudinal axis). Similarly, five duplicate test specimens are prepared.

[0105] Prepare the universal test frame as follows: Set the initial grip separation distance to a nominal gauge length of 80 mm, then zero the crosshead. Program the test frame to bring the grips closer together by intentionally loosening them by 1 mm to ensure that there is no pre-tension in the specimen at the start of the test. (During this movement, the specimen loosens between the grips.) Next, move the grips apart at a loosening rate of 1 mm / s until the loosening preload exceeds 0.05 N. (At this point, use the crosshead position signal to calculate the looseness of the specimen, the adjusted gauge length, and define the strain as zero, i.e., 0.0). Next, move the grips apart at a rate of 1 mm / s until the specimen breaks or exceeds the instrument's extension limit.

[0106] The test is performed by inserting the specimen into the grip so that its long axis is parallel to the movement of the crosshead and positioned at the center of that movement. The test is started and force ("load") and displacement data are continuously collected at a data acquisition rate of 100 Hz.

[0107] Create a graph of load (N) versus displacement (mm). Determine the peak load from the curve, and then determine the fracture sensitivity as follows: Determine the crosshead position at which the load signal decreases by 75% after reaching the peak load, and record this as the final specimen length (Lf) in units of 0.01 mm. Define the initial specimen length by the crosshead position when the loosening preload of 0.05 N is exceeded, and record this value as the initial specimen length (Li) in units of 0.01 mm. Calculate the fracture strain percentage as follows and record it in the nearest 1 percent unit. Fracture strain % = ((Lf - Li) / Li) * 100

[0108] Repeat this procedure for all five duplicate specimens in the same manner. Calculate the arithmetic mean of the fracture strain % of the five duplicate specimens and report it as fracture strain % in 1-percent increments.

[0109] Dry MD 3-point bending method The bending properties of absorbent material test specimens are measured on a universal constant-speed elongation test frame equipped with load cells where the measured force is within 1% to 99% of the cell's limit (preferred instruments are the MTS Alliance with TestSuite Software, available from MTS Systems Corp. (Eden Prairie, MN), or equivalent). Tests are performed on dry specimens. The intention of this method is to simulate the deformation created in the xy plane by the wearer of an absorbent material during normal use. All tests are performed in a room adjusted to 23°C ± 3°C and 50% ± 2% relative humidity.

[0110] The bottom stationary fixture consists of two cylindrical bars made of polished stainless steel, each 3.175 mm in diameter and 110 mm in length, mounted at each end by frictionless rolling bearings. These two bars are mounted horizontally, aligned front to back and parallel to each other, with their upper radii aligned vertically, and rotate freely around the diameter of the cylinder by frictionless bearings. Furthermore, the fixture allows the two bars to move horizontally away from each other on the track, thus allowing a gap to be set between them while maintaining the orientation of the bars. The upper fixture consists of a third cylindrical bar, also made of polished stainless steel, similarly 3.175 mm in diameter and 110 mm in length, mounted at each end by frictionless rolling bearings. When in position, the bars of the upper fixture are parallel to the bars of the lower fixture, aligned front to back, and positioned centered between the bars of the lower fixture. Both fixtures include integrated adapters suitable for fitting and securing in place at their respective positions on the universal test frame, so that the bars are perpendicular to the movement of the crossbeams of the test frame.

[0111] Set the gap ("span") between each bar of the lower fixture to 25mm ± 0.5mm (from the center of one bar to the center of the other), and align the center of the upper bar with the midpoint between each lower bar. Set the gauge (from the bottom of the upper bar to the top of the lower bar) to 1.0cm.

[0112] The thickness of the specimen ("caliper") is measured using a manual micrometer equipped with a pressure foot capable of applying a constant pressure of 0.1 psi ± 0.01 psi. The manual micrometer is a self-weight instrument with accurate readings to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, available from VWR International, or an equivalent. The pressure foot is a circular, movable surface with a flat surface having a diameter of 25.4 mm or less. The specimen is supported by a horizontal, flat reference platform that is larger than the surface of the pressure foot and parallel to the surface of the pressure foot. Zero the micrometer relative to the horizontal, flat reference platform. Place the specimen on the platform and center it under the pressure foot. Lower the pressure foot by hand at a descent rate of 3 + 1 mm / s until the pressure of the entire weight is applied to the specimen. After 5 seconds, record the thickness as caliper in units of 0.01 mm.

[0113] Two hours before the test, the absorbent article sample is conditioned at 23°C ± 3°C and 50% ± 2% relative humidity. The test sample is removed from its outer packaging, and then the protective cover / release paper is removed from the panty-fixing adhesive on the side of the sample facing the clothing. A light coating of talc powder is applied to the adhesive to reduce stickiness. For each test sample, two separate test specimens are prepared from areas on the sample that are completely free of folds or wrinkles, as follows: Referring to Figure 2, the first specimen is obtained from a position on the test sample within the intermediate region 22, such that the center of the specimen is at the intersection of the transverse midpoint of the absorbent article and line 90. The second specimen is obtained from the furthest possible rearward position on the test sample within the rear region 23 (inside the peripheral seal 230), such that the center of the specimen is at the transverse midpoint of the absorbent article. Dry specimens are prepared for MD (machine direction) bending by cutting them to a width of 50.8 mm along the CD (transverse direction, i.e., parallel to the transverse axis of the specimen) and a length of 50.8 mm along the MD (parallel axis of the specimen), maintaining their orientation after cutting, marking the surface facing the body (or the surface intended to face the body of the finished product), and labeling each test position as either the "intermediate region" or the "rear region." The thickness of each specimen is measured and recorded in 0.01 mm units as a caliper of the dry specimen, indicating the intermediate or rear region for each. Similarly, five duplicate dry specimens are prepared from the intermediate and rear test positions on five separate specimens.

[0114] The universal test frame for the deflection bending test is programmed so that the upper fixture moves downward relative to the lower fixture at a speed of 1.0 mm / second until the upper bar touches the top surface of the test specimen with a minimum force of 0.02 N, and then the crosshead is moved so that this continues for a further 12 mm. The crosshead is then immediately returned to its original position at a speed of 1.0 mm / second. Force (N) and displacement (mm) data are collected continuously at 100 Hz throughout the test.

[0115] The dry specimen is loaded so that its sides are parallel to each bar, straddling the two lower bars, and its center is positioned below the upper bar. For MD bending, the MD direction of the specimen is perpendicular to the length of the three bars. The test is started, and force and displacement data are collected continuously.

[0116] Create a graph of force (N) versus displacement (mm). From the graph, determine the maximum peak force and record it in units of 0.01 N as the dry MD peak load, indicating the test position as the intermediate or rear region. Here, calculate the maximum slope of the curve between the initial force and the maximum force (between the loaded portions of the curve) and record it in units of 0.1. Calculate the modulus of elasticity as follows, and record it as the dry MD modulus of elasticity of 0.001 N / mm². 2 Record the values ​​in units and indicate the test location as the intermediate or rear region. MD dry flexural modulus (N / mm²) 2 ) = (slope × (span) 3 ) / (4 × test piece width × (test piece caliper 3 ))

[0117] The bending stiffness was calculated as follows, and the dry MD bending stiffness was 0.1 Nmm. 2 Record the values ​​in units and indicate the test location as the intermediate or rear region.

[0118] Similarly, this procedure is repeated for all five duplicates of the dried specimen from the intermediate region and all five duplicates of the dried specimen from the rear region. The arithmetic mean of the five duplicate dried specimens representing the intermediate and rear regions is calculated separately for each parameter, with the dry MD peak load in units of 0.01 N and the dry MD flexural modulus in units of 0.001 N / mm². 2 In units of dry bending stiffness, also expressed as Nmm 2 Report the results in units, appropriately label each parameter, and indicate the intermediate or retrospective test location.

[0119] Dry CD ultra-high sensitivity three-point bending method The CD (transverse) bending properties of the test specimen are measured using a highly sensitive three-point bending test on a universal constant-speed elongation test frame equipped with load cells suitable for the force to be measured (preferred equipment is the MTS Alliance using TestSuite Software available from MTS Systems Corp. (Eden Prairie, MN), or equivalent). The intention of this method is to simulate the deformation created in the xy plane by the wearer of an absorbent material during normal use. All tests are conducted in a room adjusted to 23°C ± 3°C and 50% ± 2% relative humidity, and the test specimen is conditioned in this environment for at least two hours prior to testing.

[0120] The ultra-high-sensitivity three-point bending method is designed to maximize the force signal-to-noise ratio when testing materials with very low bending forces. The force signal is maximized by using a highly sensitive load cell (e.g., 5N), a small span (load is proportional to the cube of the span), and a wide specimen width (total measured load is directly proportional to the width). The fixture is designed so that the bending measurement is performed under tension, allowing the fixture mass to be kept to a minimum. 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 small as possible.

[0121] Referring to Figures 10A to 10C, the load cell 1001 is mounted on the fixed crosshead of the universal test frame. The ultra-high sensitivity fixture 1000 consists of three thin blades constructed from a lightweight rigid material (such as aluminum or equivalent). Each blade has a thickness of 1.0 mm, a rounded edge, 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) cut out along their horizontal edges to create a height h of 5 mm of blade material. The two outer blades 1003a and 1003b are mounted horizontally on the movable crosshead of the universal test frame, aligned parallel to each other, with their horizontal edges aligned vertically. The span s between the two outer blades 1003a and 1003b is 5 mm ± 0.1 mm (inner edge to inner edge). The central blade 1002 is mounted on a load cell on a fixed crosshead of the universal test frame. When in place, the central blade 1002 is parallel to the two outer blades 1003a and 1003b, with its center located midway between the outer blades 1003a and 1003b. The blade fixture includes a one-piece adapter suitable for fitting and securing the blade in place at each position on the universal test frame, so that the horizontal edge of the blade is perpendicular to the movement of the crossbeam of the universal test frame.

[0122] Measurements are performed on test specimens taken from raw material rolls or sheets, or from material layers excised from absorbent articles. When excising material layers from absorbent articles, care is taken to avoid any contamination or deformation of the sample layer during the process. The excised layer should not contain any residual adhesive or fibers that may have migrated from the underlying layer. To ensure that all adhesive and migrated fibers are removed, the layer is immersed in a suitable solvent that dissolves the adhesive without adversely affecting the material itself and removes all present migrated fibers. One such solvent is THF (general-purpose tetrahydrofuran, CAS 109-99-9, available from any convenient source). After solvent immersion, the material layer is completely air-dried in a manner that prevents unwanted stretching or other deformation of the material. After the material is dry, test specimens are obtained as follows: The test specimens are cut from a region of the test material that does not contain folds or wrinkles. The dried specimens are prepared for CD bending (i.e., bending perpendicular to the transverse axis of the specimen) by cutting them to a width of 50.0 mm along the CD (transverse direction, i.e., parallel to the transverse axis of the specimen) and a length of 100.0 mm along the MD (machine direction, i.e., parallel to the longitudinal axis of the specimen), maintaining their orientation after cutting, and marking the surface facing the body (or the surface intended to face the body of the finished product). Five duplicate dried specimens are prepared in the same manner.

[0123] The universal test frame is programmed so that the movable crosshead moves in the opposite direction to the fixed crosshead at a speed of 1.0 mm / s. The crosshead movement begins with the specimen 1006 flat and unbiased on the outer blades 1003a and 1003b, continues with the inner horizontal edge of the cavity 1005 within the central blade 1002 in contact with the upper surface of the specimen 1006, and is followed by an additional 4 mm crosshead movement. The crosshead stops at 4 mm and then immediately returns to zero at a speed of 1.0 mm / s. Force (N) and displacement (mm) are collected throughout at 50 Hz.

[0124] Before placing specimen 1006, the outer blades 1003a and 1003b are moved toward the central blade 1002 until a clearance C of approximately 3 mm exists between the inner horizontal edges of cavities 1004a and 1004b within the outer blades 1003a and 1003b and the inner horizontal edge of cavity 1005 within the central blade 1002, and then pass through the central blade 1002 (see Figure 10C). Specimen 1006 is positioned within clearance C so as to straddle the inner horizontal edges of cavities 1004a and 1004b within the outer blades 1003a and 1003b, with the MD (short side) of the specimen perpendicular to the horizontal edge of the blade and the body-facing surface of the specimen facing upward. Specimen 1006 is placed at the center between the outer blades 1003a and 1003b. The outer blades 1003a and 1003b are slowly moved in the opposite direction to the fixed crosshead until the inner horizontal edge of the cavity 1005 within the central blade 1002 contacts the upper surface of the test specimen 1006. The test is started, and force and displacement data are collected continuously.

[0125] Plot the force (N) against the displacement (mm). Record the maximum peak force in units of 0.001N. Calculate the area under the curve from the start of loading to the maximum peak force and express it as bending energy of 0.001N. * Record in millimeters. Recovery energy is calculated as the area under the curve where the force is unloaded from the maximum peak to 0.0 N, and is 0.001 N. * The recovery energy is recorded in millimeters. Similarly, the entire test sequence is repeated for a total of five dry specimens and five wet specimens.

[0126] For each specimen, calculate the arithmetic mean of the maximum peak force of similar specimens in units of 0.001 N and record it as the dry peak load. For each specimen, calculate the arithmetic mean of the bending energy of similar specimens in units of 0.001 N. * The calculation is performed in millimeters and reported as dry bending energy. For each specimen, the arithmetic mean of the recovery energy of similar specimens is calculated as 0.001 N. * The calculation is performed in millimeters and reported as drying recovery energy.

[0127] CD periodic stretching method up to 3% distortion The periodic tensile and recovery responses of absorbent material specimens are measured over 10 cycles of load application ("extension") and load removal ("recovery") using a universal constant-rate elongation test frame. The specimen is repeated 10 times up to 3% engineering strain, and then returned to zero engineering strain. For each cycle, 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") are calculated and reported. The intent of this method is to understand the ability of a sample to be stretched in the xy plane as a result of a force on the body and then to recover to their original state. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the specimens are conditioned in this environment for at least 2 hours prior to testing.

[0128] A suitable universal constant-speed elongation test frame is an MTS Alliance or equivalent interfaced to a computer running TestSuite control software (available from MTS Systems Corp, Eden Prairie, MN). The universal test frame is equipped with load cells in which the force to be measured is within 1% to 99% of the cell's limit. The fixtures used to grip the test specimen are lightweight (<80 grams) vise-acting clamps with knife or serrated edge gripping surfaces of at least 40 mm width. The fixtures are mounted on the universal test frame and positioned horizontally and vertically relative to one another.

[0129] Measurements are performed on test specimens taken from raw material rolls or sheets, or from material layers excised from absorbent articles. When excising material layers from absorbent articles, care is taken to avoid any contamination or deformation of the sample layer during the process. The excised layer should not contain any residual adhesive or fibers that may have migrated from the underlying layer. To ensure that all adhesive and migrated fibers are removed, the layer is immersed in a suitable solvent that dissolves the adhesive without adversely affecting the material itself and removes all present migrated fibers. One such solvent is THF (general-purpose tetrahydrofuran, CAS 109-99-9, available from any convenient source). After solvent immersion, the material layer is air-dried completely in a manner that prevents unwanted stretching or other deformation of the material. After the material is dry, test specimens are obtained. Test specimens are cut from an area of ​​the test material that does not have any remaining folds or wrinkles. The test specimen is approximately 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 test specimens from absorbent articles of different sizes and widths, the total length of the test specimen (L) total ) may vary from product to product, and therefore the results are 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 intended longitudinal axis). Test specimen width (w) = 25.4 mm. Total test specimen length (L total Measure the distance and record it in 0.1 mm increments. Prepare five duplicate specimens in the same manner.

[0130] The thickness (t) of the specimen is measured using a manual micrometer equipped with a clamp capable of applying a steady pressure of 0.1 psi ± 0.01 psi. The manual micrometer is a self-weight instrument with accurate readings to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, available from VWR International, or an equivalent. The clamp is a circular movable surface with a flat surface having a diameter of 25.4 mm or less. The specimen is supported by a horizontal, flat reference platform that is larger than the surface of the clamp and parallel to the surface of the clamp. Zero the micrometer relative to the horizontal, flat reference platform. Place the specimen on the platform and center it under the clamp. Lower the clamp by hand at a descent rate of 3 + 1 mm / s until the pressure of the entire weight is applied to the specimen. After 5 seconds, record the thickness as the specimen thickness (t) in units of 0.01 mm.

[0131] Prepare the universal test frame as follows: Set the initial grip separation distance to a nominal gauge length (L) that is shorter than the total length of the test specimen. nominal Set to (i.e., L) so that the test specimen can be securely gripped at both ends. nominal <L total Next, the crosshead is set to zero. The test frame is programmed to bring the grips closer together by intentionally loosening them by 1 mm to ensure that there is no pre-tension in the specimen at the start of the test. (During this movement, the specimen loosens between the tensile grips.) The grips are then moved apart at a loosening rate of 1 mm / s until the loosening preload exceeds 0.05 N. At this point, the following occurs: 1) The crosshead position signal (mm) is set to the loosening of the specimen (L slack ) is defined as follows: 2) The initial test specimen gauge length (L0) is defined as nominal gauge length + looseness L0 = L nominal +L slackThe calculation is performed as follows, where the unit is millimeters. 3) Set the crosshead extension (ΔL) to zero (0.0 mm). 4) Set the crosshead displacement (mm) to zero (0.0 mm). At this position, the engineering strain is zero, i.e., 0.0. The engineering strain is calculated as the change in length (ΔL) divided by the initial length (L0). Engineering strain = ΔL / L0. For one test cycle, the grips move away from each other at an initial velocity of 1 mm / s until they exceed the engineering strain endpoint of 0.03 mm / mm, and immediately thereafter, the grips move towards each other at an initial velocity of 1 mm / s until the crosshead signal is less than the crosshead return position of 0 mm. The test cycle is repeated until a total of 10 cycles are completed.

[0132] The test is performed by inserting the specimen into the grip so that its long axis is parallel to the movement of the crosshead and positioned at the center of that movement. The test is started, and time, force, and displacement data are continuously collected at a data acquisition rate of 100 Hz.

[0133] Create load (N) versus displacement graphs for all 10 cycles. For each cycle, do the following: Record the peak load in 0.01 N units. Calculate the area under the load-versus-displacement curve from the start of the cycle to the end of the strain at 0.03 mm / mm (during the load portion of the cycle) as the peak energy (E peak Calculate the return energy (E) and record it in units of 0.01 N·mm. The return energy (E) is defined as the area under the load-displacement curve from the strain endpoint of 0.03 mm / mm to the crosshead return of 0 mm (during the unloading portion of the cycle). return ) calculate 0.01N * The recovery energy is recorded in millimeters. The normalized peak energy (NE) is calculated by dividing the peak energy by the initial length. peak ) calculate (NE peak =E peak Record the return energy ( / L0) in units of 0.01 mN. Normalize the return energy (NE) by dividing the return energy by the initial length. return ) calculate (NE return =E returnRecord in units of 0.01 mN (L0). NE peak and NE return The unit is millinewtons (mN).

[0134] Here, we create a graph of engineering stress (σ) versus engineering strain for all 10 cycles, and perform the following for each cycle: N / mm 2 The engineering stress in units of σ is obtained by dividing the load by the cross-sectional area of ​​the test specimen, where the cross-sectional area is the width (w) multiplied by the thickness (t) of the test specimen (σ = load / (w × t)). The modulus of elasticity, or the slope of the stress-strain curve, is determined for the line between the point of minimum force and the point of maximum force (between the loaded parts of the cycle), and the modulus of elasticity is set to 0.01 N / mm². 2 Record the values ​​in units of 0.01 N / mm. Calculate the stiffness by multiplying the elastic modulus by the thickness of the specimen and record it as tensile stiffness in units of 0.01 N / mm. Define the strain of the specimen at the start of the cycle as the strain when the load exceeds 0.05 N of slack preload for that cycle (during the loading portion of the cycle), and record it as the initial cycle strain in units of 0.01 mm / mm. Define the strain of the specimen at the end of the cycle as the strain when the load falls below 0.05 N of preload for that cycle (during the unloading portion of the cycle), and record it as the permanent strain in units of 0.01 mm / mm. Repeat the entire procedure similarly for all five copies.

[0135] The arithmetic mean of five replicated specimens is calculated for each parameter for each of the 10 cycles and reported as peak load in 0.01 N units, normalized peak energy in 0.01 mN units, normalized recovery energy in 0.01 mN units, tensile stiffness in 0.01 N / mm units, initial cycle strain in 0.01 mm / mm units, and permanent strain in 0.001 mm / mm units.

[0136] Method for measuring the spacing and area of ​​structural joint site patterns The spacing between inconspicuous structural joints used to create a quilt-like pattern on an absorbent material sample, and the total area occupied by these elements in a specific region of the sample, are measured on an image of the absorbent material sample acquired using a flatbed scanner. The scanner can scan in reflectance mode at a resolution of 2400 dpi and 8-bit grayscale. A suitable scanner is the Epson Perfection V750 Pro from Epson America Inc. (Long Beach, CA, USA) or an equivalent. The scanner is connected to a computer running an image analysis program. A suitable program is ImageJ v.1.52 (National Institute of Health, USA) or an equivalent. The sample image is distance-calibrated against an acquired NIST-certified ruler image. To allow for maximum contrast, the test specimen is backed with a uniformly colored opaque black background before image acquisition. All tests are performed in a humidified room maintained at approximately 23±2°C and approximately 50±2% relative humidity.

[0137] Prepare the test specimen as follows: Remove the absorbent article from its packaging. If the article is folded, gently unfold it and smooth out all wrinkles. If wings are present, extend them, but leave the release paper intact. Prepare the test specimen for approximately 2 hours before testing at approximately 23°C ± 2°C and approximately 50% ± 2% relative humidity.

[0138] The image is obtained as follows: The ruler is placed on the scanner bed so that it is oriented parallel to the side of the scanner glass. The image of the ruler (calibration image) is acquired in reflective mode at a resolution of 2400 dpi (approximately 94 pixels / mm) and 8-bit grayscale. The calibration image is saved as an uncompressed TIFF format file. After acquiring the calibration image, the ruler is removed from the scanner glass and the test specimen is scanned under the same scanning conditions as follows: The test specimen is placed in the center of the scanner glass and, if necessary, secured so that the body-facing surface of the specimen is flat against the scanner's glass surface. The specimen is oriented so that the entire specimen is within the glass surface. A black background is placed over the specimen, the scanner lid is closed, and a scan image of the entire specimen is acquired using the same settings as used for the calibration image. The specimen image is saved as an uncompressed TIFF format file.

[0139] The sample image is analyzed as follows: The calibration image file is opened in the image analysis program, and the image resolution is calibrated using an embossed ruler to determine the number of pixels per millimeter. Next, the sample image is opened in the image analysis program, and the distance scale is set using the image resolution determined from the calibration image. Then, the pattern of embossed elements present on the sample in the image is visually inspected, and the zones of the pattern to be analyzed are identified. For example, an absorbent article can be divided into three equally lengthed zones in the machine direction, such as Zone 1, which is the front 1 / 3 zone; Zone 2, which is the middle 1 / 3 zone; and Zone 3, which is the edge 1 / 3 zone. Using the image analysis tool, the shape is drawn along the perimeter of the first inconspicuous zone to be analyzed. The area of ​​this first zone is measured, and the total area of ​​Zone 1 is 0.01 mm². 2 Record in units of 0.01 mm. Here, measure the area of ​​individual inconspicuous embossed elements located inside the perimeter of Zone 1 as follows: Draw the smallest possible boundary circle around each embossed element so that no part of the embossed element lies outside the boundary circle. Next, measure the area of ​​the boundary circle of that embossed element and record the embossed element area as 0.01 mm. 2Record in units of 0.01 mm. Similarly, measure the area of ​​each embossed element, including the portion of the embossed element located within Zone 1, and record each in units of 0.01 mm. 2 Record in units. Here, the areas of all embossed elements within Zone 1 are summed up, and the total embossed element area of ​​Zone 1 is 0.01 mm². 2 Record in units of 0.01 mm. Divide the total embossed element area of ​​Zone 1 by the total area of ​​Zone 1, then multiply by 100 and record as the percentage of the total area of ​​Zone 1 represented by the embossed elements. Measure the spacing between each inconspicuous embossed element inside Zone 1 as follows: Measure the distance from the center of the minimum boundary circle drawn around an inconspicuous embossed element inside Zone 1 to the center of the minimum boundary circle drawn around the nearest adjacent inconspicuous embossed element inside Zone 1, as described herein, and record this distance as the embossed spacing in units of 0.01 mm. Repeat this process for all adjacent embossed elements inside Zone 1, recording each distance in units of 0.01 mm. Next, calculate the arithmetic mean of all measured embossed spacings between the nearest adjacent elements inside Zone 1 and record it as the Zone 1 embossed spacing in units of 0.01 mm.

[0140] Similarly, the entire procedure is repeated for each additional zone containing embossed elements present on the test sample, and these zones are labeled accordingly as Zone 2, Zone 3, etc.

[0141] Nonwoven fabric thickness-pressure method The thickness of the test specimen is measured as the distance between the reference platform on which the test specimen is placed and the presser that applies a specific amount of pressure to the test specimen over a specific period of time. For the purposes of this specification, the thickness is measured under two different confinement pressures (7 g / cm²). 2 and 70g / cm³ 2 The measurements are taken and reported. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the test specimens are conditioned in this environment for at least 2 hours before testing.

[0142] The thickness is determined by a constant pressure (7g / cm²). 2 and 70g / cm³ 2The measurement is performed using a manual micrometer equipped with a clamp capable of applying pressure to the test specimen. The manual micrometer is a self-weight instrument with accurate readings to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, available from VWR International, or an equivalent. The clamp is a flat, grounded, circular movable surface with a diameter smaller than the test specimen and capable of applying the required pressure. A suitable clamp has a diameter of 25.4 mm, but a smaller or larger clamp can be used depending on the size of the test specimen being measured. The test specimen is supported by a horizontal, flat reference platform that is larger than the surface of the clamp and parallel to the surface of the clamp. The system is calibrated and operated according to the manufacturer's instructions.

[0143] Measurements are performed on test specimens taken from raw material rolls or sheets, or from material layers excised from absorbent articles. When excising material layers from absorbent articles, care is taken to avoid any contamination or deformation of the sample layer during the process. The excised layer should not contain any residual adhesive or fibers that may have migrated from the underlying layer. To ensure that all adhesive and migrated fibers are removed, the layer is immersed in a suitable solvent that dissolves the adhesive without adversely affecting the material itself and removes all present migrated fibers. One such solvent is THF (general-purpose tetrahydrofuran, CAS 109-99-9, available from any convenient source). After solvent immersion, the material layer is air-dried completely in a manner that prevents unwanted stretching or other deformation of the material. After drying, the test specimen must be obtained from an area free of folds or wrinkles and larger than the presser foot.

[0144] 7g / cm 2To measure the thickness at the confinement pressure, first zero out the micrometers against a horizontal, flat reference platform. Place the specimen on the platform with the test position centered under the clamp. Gently lower the clamp at a rate of 3.0 mm ± 1.0 mm / sec until the full pressure is applied to the specimen. After waiting 5 seconds, record the thickness of the specimen in 0.01 mm increments. Repeat similarly for a total of 10 duplicate specimens. 7 g / cm 2 The arithmetic mean of all thickness measurements obtained at the confinement pressure was calculated to be 7 g / cm². 2 The thickness should be reported in units of 0.01 mm.

[0145] 70g / cm 2 To measure the thickness at the confinement pressure, first zero out the micrometers against a horizontal, flat reference platform. Place the specimen on the platform with the test position centered under the clamp. Gently lower the clamp at a rate of 3.0 mm ± 1.0 mm / sec until the full pressure is applied to the specimen. After waiting 5 seconds, record the thickness of the specimen in 0.01 mm increments. Repeat similarly for a total of 10 duplicate specimens. 70 g / cm 2 The arithmetic mean of all thickness measurements obtained at the confinement pressure was calculated to be 70 g / cm². 2 The thickness should be reported in units of 0.01 mm.

[0146] Methods for measuring width, length, and area Simple dimensions such as width, length, and area of ​​a specific location (as described herein) on the surface of an absorbent article are measured on an image of the absorbent article sample (or a prepared test specimen of a given zone) acquired using a flatbed scanner. The scanner can scan in reflectance mode with a resolution of 2400 dpi and 8-bit grayscale. A suitable scanner is the Epson Perfection V750 Pro from Epson America Inc. (Long Beach, CA, USA) or an equivalent. The scanner is connected to a computer running an image analysis program. A suitable program is ImageJ v.1.52 (National Institute of Health, USA) or an equivalent. The sample image is distance-calibrated against an acquired NIST-certified ruler image. To allow for maximum contrast, the test specimen is backed with a uniformly colored opaque black background before image acquisition. All tests are performed in a humidified room maintained at approximately 23 ± 2°C and approximately 50 ± 2% relative humidity.

[0147] The test specimens are prepared as follows: Remove the absorbent article from its packaging. If the article is folded, gently unfold it and smooth out all wrinkles. If wings are present, stretch them out, but leave the release paper intact. Similarly, prepare a total of five identical, flawless test specimens. Prepare the test specimens for approximately 2 hours before testing at approximately 23°C ± 2°C and approximately 50% ± 2% relative humidity. Notably, the area of ​​the test specimens prepared as specified in the sections on absorbent article caliper, basis weight, and basis weight by density method described herein is also measured using this imaging technique, and no further preparation of these specimens is required.

[0148] The image is obtained as follows: The ruler is placed on the scanner bed so that it is oriented parallel to the side of the scanner glass. The image of the ruler (calibration image) is acquired in reflective mode with a resolution of 2400 dpi (approximately 94 pixels / mm) and 8-bit grayscale. The calibration image is saved as an uncompressed TIFF format file. After acquiring the calibration image, the ruler is removed from the scanner glass and the test specimen or test piece is scanned as follows: The test specimen or prepared test piece is placed in the center of the scanner glass, and if necessary, the body-facing surface of the specimen or prepared test piece is fixed so that it is flat and facing the scanner glass surface. The test specimen or prepared test piece is oriented so that the entire specimen or prepared test piece is within the glass surface. A black background is placed over the test specimen or prepared test piece, the scanner lid is closed, and a scan image of the entire test specimen or prepared test piece is acquired with the same settings as those used for the calibration image. The image of the test specimen or prepared test piece is saved as an uncompressed TIFF format file.

[0149] The width and length are measured by analyzing the test sample images as follows: The calibration image file is opened in the image analysis program, and the image resolution is calibrated using an imaged ruler to determine the number of pixels per millimeter. Next, the test sample image is opened in the image analysis program, and the distance scale is set using the image resolution determined from the calibration image. Linear measurements are performed using the line measurement tool in the image analysis software. As shown in Figures 2 and 4, the widths WS, W1, W2, and W3 and the lengths LC and LT are measured using the positions of each dimension as specified herein. A total of five duplicate test samples are imaged and analyzed in the same manner, and each linear parameter is recorded in 0.1 mm units. The arithmetic mean of the five duplicate test samples is calculated for each linear parameter and reported in 0.1 mm units as WS, W1, W2, W3, LC, and LT.

[0150] The specimen images of the central and outer absorptive zones are analyzed as follows: The calibration image file is opened in the image analysis program, and the image resolution is calibrated using an embodied ruler to determine the number of pixels per millimeter. Next, the specimen image is opened in the image analysis program, and the distance scale is set using the image resolution determined from the calibration image. Area measurement is performed by drawing a shape extending along the outer perimeter of the prepared specimen using the freehand selection tool or equivalent in the image analysis software. Here, the area of ​​the drawn shape is measured and expressed as 0.01 mm². 2 Record in units. Zones are indicated as either the central absorbent zone or the outer absorbent zone, and the corresponding sample number is also indicated. Similarly, measure and record the area of ​​each of the five replicated test specimens from each zone (central absorbent zone and outer absorbent zone), and repeat until the corresponding sample number is indicated for each replica. Now return to the basis weight portion of the absorbent article caliper, basis weight, and density method.

[0151] Absorbent Article Caliper, Basis Weight, and Density Method The caliper, basis weight, and density methods specify how to measure these parameters at two different test locations on an absorbent article sample. Referring to Figure 2, the test locations include the central absorbent zone 306 and the outer absorbent zone 325. All tests are performed in a controlled room at 23°C ± 3°C and 50% ± 2% relative humidity.

[0152] Two hours before testing, the absorbent material samples are conditioned at 23°C ± 3°C and 50% ± 2% relative humidity. The test samples are removed from their outer packaging, and then the protective cover / release paper is removed from the panty-fastening adhesive on the garment-facing side of the sample. To reduce tackiness, a light dusting of talc powder is sprinkled on the panty-fastening adhesive. In the same manner, a total of five duplicate test samples are prepared. The test samples are sequentially labeled as Sample 1 to Sample 5 by marking a small number on the back sheet / garment side of each sample.

[0153] Absorbent article caliper The caliper (or "thickness") is 7 g / cm². 2 Measurements are taken at specific test locations on an absorbent material sample using a manual micrometer equipped with a clamp capable of applying constant pressure. The manual micrometer is a self-weight instrument with accurate readings to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, available from VWR International, or an equivalent. The clamp is a flat, circular, movable surface with a diameter of 25.4 mm or less. The test sample is supported by a horizontal, flat reference platform that is larger than the surface of the clamp and parallel to the surface of the clamp. Zero the micrometer relative to the horizontal, flat reference platform. Place the test sample on the platform with the test location centered under the clamp. Lower the clamp by hand at a descent rate of 3 ± 1 mm / s until the full weight pressure is applied to the sample. After 5 seconds, record the thickness as an absorbent material caliper in 0.01 mm units, indicating the test location as either the central absorbent zone or the outer absorbent zone, and also indicating the sample number as previously marked. As specified, measure the caliper in three separate, non-overlapping regions within the central absorbent zone 306 of each intact absorbent article sample. Calculate the arithmetic mean of the caliper values ​​collected for the central absorbent zone 306 in all five replicated samples and report it as the absorbent article caliper in the central absorbent zone to the nearest 0.01 mm. Next, measure the caliper in three separate, non-overlapping regions within the outer absorbent zone 325 of each intact absorbent article sample. Calculate the arithmetic mean of the caliper values ​​collected for the outer absorbent zone 325 in all five replicated samples and report it as the absorbent article caliper in the outer absorbent zone to the nearest 0.01 mm. Using similarly prepared and numbered test samples, proceed to basis weight measurement.

[0154] Basis weight of absorbent articles The basis weight of the central absorbent zone 306 and the outer absorbent zone 325 is measured separately for each prepared test specimen using specially machined cutting dies. The first cutting die for the precise shape of the outer absorbent zone is prepared so that the cutting line of the die aligns precisely with the perimeter of the entire area designated as the outer absorbent zone 325, as shown in Figure 2. The second cutting die for the precise shape of the central absorbent zone is prepared so that the cutting line of the die aligns precisely with the perimeter of the entire area designated as the central absorbent zone 306, as shown in Figure 2. It will be understood that a set of specially machined cutting dies will need to be prepared for each unique product design and for each different product size. The mass of the central absorbent zone 306 and the outer absorbent zone 325 on the test specimen is measured as follows: The first specially machined cutting die is aligned with the perimeter of the outer absorbent zone 325, and a first test specimen containing both the outer absorbent zone and the central absorbent zone is punched out. Here, a specially prepared second cutting die is aligned with the periphery of the central absorbent zone 306 on the first specimen, and a second specimen containing only the central absorbent zone 306 is punched out. The remaining portion of the first specimen will contain only the outer absorbent zone 325. The corresponding sample number is labeled on the backsheet / garment side of each of these prepared specimens. The specimens must be handled carefully so as not to lose any particles or material fibers contained within each. The mass of the specimen containing the central absorbent zone is recorded, recorded in units of 0.001 g as the mass of the central absorbent zone of the absorbent article, and the sample number is also indicated. Here, the mass of the specimen containing the outer absorbent zone is recorded, recorded in units of 0.001 g as the mass of the outer absorbent zone of the absorbent article, and the sample number is also indicated. Similarly, the central absorbent zone and the outer absorbent zone are punched out, and the remaining four duplicate specimens are each labeled with a corresponding sample number. The mass of each zone is recorded in units of 0.001 g, and the zone is indicated as either the central absorbent zone or the outer absorbent zone of the absorbent article, along with the corresponding sample number. Then, proceeding as described herein, the width, length, and area measurement methods are performed to measure the area of ​​the test specimens representing the central absorbent zone and the outer absorbent zone of the absorbent article.After obtaining the area of ​​each zone, the basis weight is calculated by dividing the mass (g) by the area (converted to square meters), and the basis weight of the absorbent material is 0.1 g / m². 2 The data is recorded in units, and the zone is indicated as either the central absorption zone or the outer absorption zone, along with the corresponding sample number. The arithmetic mean of all basis weights of the five test specimens in the central absorption zone is calculated, and 0.1 g / m² is used as the basis weight of the absorbent material in the central absorption zone. 2 Report in units. Calculate the arithmetic mean of all basis weights of the five test replicas in the outer absorbent zone, and use 0.1 g / m² as the basis weight of the absorbent article in the outer absorbent zone. 2 Report in units. All of these prepared test specimens of the central and outer absorbent zones of the absorbent article are to be used for basis weighting of the inner core layer, as described herein.

[0155] Absorbent material density The densities of the central absorption zone 306 and the outer absorption zone 325 are calculated as follows: For the central absorption zone specimen from sample 1, g / m³ 2 Divide the basis weight (basis weight of absorbent material, central absorbent zone, sample 1) by the caliper (caliper of absorbent material, central absorbent zone, sample 1) in mm units, then divide the quotient by 1000 to obtain the absorbent material density of the central absorbent zone as 0.001 g / m³. 3 Record in units. Similarly, calculate the density of the central absorbent zone for all five replicated specimens. Here, calculate the arithmetic mean of the densities of all five specimens in the central absorbent zone and use 0.001 g / m³ as the absorbent material density of the central absorbent zone. 3 Report in units. For the outer absorption zone test specimen from Sample 1, g / m 2 The basis weight in units (basis weight of absorbent material, outer absorbent zone, sample 1) is divided by the caliper in mm (caliper of absorbent material, outer absorbent zone, sample 1), and then the quotient is divided by 1000 to obtain the absorbent material density of the outer absorbent zone as 0.001 g / m². 3Record in units. Similarly, calculate the density of the outer absorbent zone for all five replicated specimens. Here, calculate the arithmetic mean of the densities of all five specimens in the outer absorbent zone and use 0.001 g / m³ as the absorbent article density of the outer absorbent zone. 3 Report in units.

[0156] internal core layer basis volume The basis weight of the inner core layer at points within the central and outer absorption zones is typically known by the manufacturer from the product manufacturing specifications. However, if the basis weight is unknown for a given article, it can be measured by the following method.

[0157] The basis weight of the inner core layer within the central absorbent zone 306 and the outer absorbent zone 325 is measured separately for each absorbent article specimen prepared in the sections on absorbent article caliper, basis weight, and density method basis weight as described herein. There will be five absorbent article specimens (labeled Samples 1-5) for the central absorbent zone and five absorbent article specimens (likewise labeled Samples 1-5) for the outer absorbent zone. Note that the measured area values ​​of each specimen previously recorded in the sections on absorbent article caliper, basis weight, and density method basis weight are also used to calculate the basis weight of the inner core layer from each of these regions.

[0158] Remove the inner core layer from the specimen, record its mass, and calculate the basis weight as follows: Start with the absorbent article specimen from the central absorbent zone of Sample 1. Carefully remove the top sheet layer, back sheet film, upper nonwoven fabric layer, and lower nonwoven fabric layer from the inner core layer of the specimen, ensuring that no particles or fibers are lost from the inner core layer during the process. Depending on the unique structure of the absorbent article, it may be necessary to remove additional layers from the absorbent article specimen to obtain a final specimen containing only the inner core layer. Record the mass of the inner core layer specimen in units of 0.001 g and label it "Central Absorbent Zone, Sample 1". Divide the mass of the inner core layer from the central absorbent zone of Sample 1 by the area of ​​the central absorbent zone of the absorbent article of Sample 1 (previously measured) to obtain the basis weight of the inner core layer labeled "Central Absorbent Zone, Sample 1", which is 0.1 g / m². 2 Record in units. Similarly, repeat this procedure until the basis weight of the inner core layer from the central absorption zone is measured and recorded for each of the five central absorption zone specimen replicas from samples 1-5. Calculate the arithmetic mean of all the basis weight values ​​obtained for all five central absorption zone replicas and use 0.1 g / m² as the basis weight of the inner core layer of the central absorption zone. 2 Report in units. Similarly, repeat this entire procedure for five absorbent article test specimens from the outer absorbent zone of samples 1-5, calculate the arithmetic mean of all five basis weight values, and use 0.1 g / m² as the basis weight of the inner core layer of the outer absorbent zone. 2 Report in units.

[0159] Z compression method The Z-compression method measures the compression behavior of a specimen along the z-direction on a Constant Rate of Extension (CRE) universal mechanical test system, using a load cell in which the measured force is within 1% to 99% of the cell's limit (preferably 100 N). A suitable instrument is the MTS Alliance, using TestSuite Software or equivalent, available from MTS Systems Corp. (Eden Prairie, MN). All tests are performed in a controlled room at 23°C ± 3°C and 50% ± 2% relative humidity.

[0160] The upper and lower fixtures of the test system are circular parallel plate compression platens made of stainless steel. The platen mounted on the movable CRE fixture has a diameter of 40 mm, and the platen mounted on the stationary CRE fixture has a diameter greater than 40 mm. Both platens have adapters that fit into the mounts of the CRE test machine, and the platens can be fixed together with their opposing surfaces positioned along parallel planes perpendicular to the movement of the crossbeam of the CRE test machine.

[0161] Two hours before the test, the absorbent article sample is conditioned at 23°C ± 3°C and 50% ± 2% relative humidity. The test sample is removed from its outer packaging, and then the protective cover / release paper is removed from the panty-fixing adhesive on the side of the sample facing the clothing. A light coating of talc powder is applied to the adhesive to reduce stickiness. A 40 mm diameter circular die is used to obtain test specimens for measurement. Test specimens are obtained from two separate test locations on the absorbent article test sample from areas completely free of folds or wrinkles, as follows: Referring to Figure 4, the first test specimen is obtained from the rear end of the central absorbent zone 306, more specifically from the area indicated as the region where W3 is measured, and the test specimen is in the center of this test location. The second test specimen is obtained from the rear end of the outer absorbent zone 326, and the test specimen is in the center of this test location, inside the surrounding seal, and ideally does not include the central absorbent zone portion. Similarly, five replicated specimens are prepared from the central and outer absorption zones of five replicated test samples.

[0162] A universal test frame for compression testing is prepared, and the force and distance are measured for one cycle of loading (compression) and unloading (recovery) as follows: The movement of the crosshead is programmed so that the upper platen moves downward relative to the lower platen at a speed of 0.2 mm / s until the endpoint load of 8.66 N (6.9 kPa) is reached, and then the crosshead immediately returns to its original gauge (platen separation distance).

[0163] The test is conducted as follows: The platen is moved so that the initial distance (gauge) between the contact surfaces of the platen is 25 mm, and then the crosshead and load cell are zeroed out. The midpoint of the longitudinal and transverse directions of the test specimen is centered under the upper platen, and the test specimen is placed on the bottom platen with the side facing the body facing upwards. The position of the upper platen is manually adjusted so that its contact surface is approximately 1 mm above the top surface of the test specimen. The test is started, and force (N) and displacement (mm) data are continuously collected at a speed of 100 Hz.

[0164] A graph of force (N) versus thickness (mm) is constructed across the array of data collected for the entire cycle. Note that at each data point, the thickness is the original gauge (25 mm) minus the crosshead position (mm). From the resulting force (N) versus thickness (mm) curve, the area under the load (compression) portion of the curve from the initial thickness to the minimum thickness is calculated, and the z-compression energy is given as 0.1 N. * Record the results in millimeters, and indicate the test location as either the central absorption zone or the outer absorption zone.

[0165] Similarly, this procedure is repeated for all five replicate specimens from the central absorption zone and all five replicate specimens from the outer absorption zone. The arithmetic mean of all five replicates from each test location is calculated and reported as 0.1 N of Z compression energy. * Report in millimeters, indicating the central absorption zone or the outer absorption zone.

[0166] Micro-CT measurement method Micro-CT measurement is used to acquire cross-sectional images of a specimen, enabling visualization of the microstructure of absorbent articles, including the interconnectivity of layers within the article in a specific area of ​​interest. These images allow for qualitative and quantitative evaluation in relation to the proximity of adjacent layers within the specimen, as well as the resulting size and shape of specific zones located within the specimen. This method is based on the analysis of 3D X-ray sample images obtained with a micro-CT instrument (a preferred instrument is the Scanco μCT 50, available from Scanco Medical AG (Switzerland), or an equivalent). This micro-CT instrument is a conical beam microtomograph with a shielding cabinet. A maintenance-free X-ray tube is used as a source with an adjustable focal diameter. The X-ray beam passes through the sample, and a portion of the X-rays are attenuated by the sample. The degree of attenuation correlates with the mass of the material through which the X-rays must pass. The transmitted X-rays continue to enter a digital detector array, generating a 2D projection image of the sample. A 3D image of a sample is generated by collecting multiple individual projection images of the rotated sample and then reconstructing these projection images as a single 3D image. The instrument works in conjunction with software running on a computer to control image acquisition and reconstruction of raw data into a 3D image. The 3D image is then analyzed using image analysis software (preferred image analysis software is MATLAB, available from The Mathworks, Inc. (Natick, MA), and Avizo 2022.2, available from Visualization Sciences Group / FEI Company (Burlington, MA), or equivalent) to identify specific zones in the specimen and measure the distance between individual layers and zones, the thickness of the zones, and any angles that occur when one zone transitions to another within the specimen.

[0167] Sample preparation: The test specimens are cut from the test sample using a very sharp blade as follows. The test specimens are obtained from areas free of folds or wrinkles, taking care not to contaminate or strain the specimens during the preparation process. The test specimens are cut from an area of ​​the test sample in such a way that they include a portion of both the central absorbent zone and the outer absorbent zone, including any transition zones that may exist. The diameter of the test specimens is approximately 90 mm. Similarly, a total of three duplicate test specimens are prepared from three different test samples. The test specimens are conditioned for approximately 2 hours before testing at approximately 23°C ± 2°C and approximately 50% ± 2% relative humidity.

[0168] Image acquisition: The micro-CT instrument is set up and calibrated according to the manufacturer's specifications. The specimen is placed on a low-density foam and placed in a suitable holder. This allows the specimen to be placed horizontally and scanned with minimal attenuation from the surrounding material. A single 3D dataset of consecutive 13 μm (micron) isotropic voxels is collected. The 3D dataset has dimensions of 96.7 mm on each side in the XY plane and has enough slices to completely cover the entire Z direction of the specimen. Images are acquired using a 70 kev and 114 μA source without the use of further low-energy filters. These current and voltage settings can be optimized to ensure sufficient X-rays penetrate the specimen and maximize the contrast of the projection data, but once optimized, they are kept constant for all substantially similar specimens. A total of 3000 projection images are obtained with a total integration time of 500 milliseconds and an average of 4 per projection. The projected images are reconstructed into a 3D dataset with an isotropic spatial resolution of 13 μm (microns) and saved in 16-bit RAW format to preserve the complete detector output signal for analysis. For optimal visualization, the data is scaled to 8 bits using a scale factor of 0.4 and subsampled to a resolution of 26 microns.

[0169] Image processing: The 3D dataset is loaded into image analysis software and cropped into a rectangular prism 3D image of the analysis region by removing the surrounding holder and low-density mounting material from the 3D dataset. The cropping is performed so that the maximum amount of specimen within the analysis region is retained in the 3D image and the empty space above and below the specimen is minimized. Within the 3D image, averaging is performed every 10 cross-sectional slices to reduce noise. This averaging generates thicker slices representing a 260-micron thick slab along the observation direction. The in-plane resolution is 26 microns.

[0170] The 3D image is oriented so that the top surface (top sheet, or the main body size of the test specimen) is as close to parallel to the XY plane as possible. Here, qualitative observations can be made regarding the proximity of adjacent layers present in the test specimen, the interconnectivity between the layers, and the overall shape of the various zones present (i.e., the central absorbent zone and the outer absorbent zone, as well as the transitions between the zones). In addition to qualitative observations, simple quantitative measurements (e.g., zone thickness, distance between zones, angle formed as a transition from one zone to another) can be made using measurement tools available within the image analysis software.

[0171] Examples / Data The following data and examples, including comparative examples, are provided to aid in the description of the upper nonwoven layer and lower nonwoven layer, and / or absorbent articles, as described herein. The exemplified structures are provided for illustrative purposes only and many modifications thereto are possible without departing from the spirit and scope of this disclosure, and should not be construed as limiting the invention.

[0172] Testing of nonwoven fabric layer materials In the absorbent core structure described in this specification, a series of measurements were performed on the non-woven material to evaluate the ability of the material that functions as the upper non-woven layer and / or the lower non-woven layer. Samples A to G are examples according to this disclosure. Comparative sample H is a comparative example. Samples A to G and comparative sample H are described in Table 1 below.

[0173] Samples A to G and comparative sample H were evaluated according to the CD cyclic stretching method up to 3% strain, the breaking strain method, the dry CD ultra-sensitive three-point bending method, and the non-woven thickness-pressure method. The results are shown in Table 2.

[0174]

Table 1

[0175]

Table 2

[0176] Suitable non - woven fabric materials for the upper non - woven fabric layer and / or the lower non - woven fabric layer are those that can be distorted (elongated) with a balanced stretch and return to their original state. Thus, it is considered useful for the absorbent core structure and / or the absorbent article to be able to deform and recover during body movement. The 3D inner core layer shape described herein is configured to fit closely to the wearer's genitalia and fit between the major labia. Thus, a particularly suitable non - woven fabric material for the upper non - woven fabric layer can provide fluid - handling performance that can effectively transport fluid deep within the inner core layer and help provide a comfortable fit that is snug against the dry - feeling body. To achieve this, a suitable non - woven fabric material for the upper non - woven fabric layer allows the fluid to be efficiently discharged from the upper non - woven fabric layer to the lower inner core layer, and thus has a relatively low density (e.g., 7 g / cm 2 under a pressure of 0.03 - 0.07 g / cm 3 ). In addition, a suitable non - woven fabric material for the upper non - woven fabric layer can maintain a relatively bulky thickness even under a high body compression force (i.e., a pressure of 70 g / cm 2 ), so that the fluid present within the inner core layer cannot be discharged from the absorbent core structure and cause a wet feeling on the body. Suitable non - woven fabric materials for the upper non - woven fabric layer and / or the lower non - woven fabric layer may also need to be able to conform to the complex 3D inner core layer shape described herein.

[0177] Samples A - C and E were found to be suitable materials for the upper non - woven fabric layer and / or the lower non - woven fabric layer. In particular, Samples A - C and E were demonstrated to have a permanent strain of 0.013 mm / mm or less, that the material could be elongated and recovered, and had a breaking strain of more than 10% before tearing. Samples A - C and E also had a 0.03 N *With a drying recovery energy exceeding mm, it required less energy to bend while recovering from bending (1.6 N). * (Evided by dry bending energy of less than mm). Samples A, B, C, and E are 7 g / cm². 2 Under this pressure, 0.03~0.07 g / cm³ 3 It has a relatively low density, and is 7 g / cm³ in size of 0.80-1.21 mm. 2 The thickness at pressure is shown, demonstrating that these materials have a bulkier, more open fibrous network structure that can contribute to efficient fluid handling performance.

[0178] Sample D was found to have a permanent strain of 0.016 mm / mm, demonstrating that the material is likely to elongate significantly during manufacturing and / or use without recovering to its initial state. Therefore, it is considered that this material may not be able to maintain the structural stability and shape of the inner core layer. At the same time, sample D was found to have a permanent strain of 70 g / cm² at 0.19 mm. 2 As demonstrated by its thickness, it was found to be highly compressible under body pressure, suggesting that this material is likely to become denser under body compression and that the inner core layer will not adequately expel the fluid. Samples F and G are 0.03N * The samples exhibited a dry recovery energy of less than mm, demonstrating that the material did not recover from deformation and was insufficient to function as an upper nonwoven layer. However, when combined with the upper nonwoven layers described herein, samples D, F, and G are suitable materials for the lower nonwoven layer.

[0179] Comparative sample H exhibited a fracture strain of less than 5% and a thickness of less than 0.2 mm at 70 g / cm². Furthermore, comparative sample H was found to tear when wet. Therefore, comparative sample H is insufficient to function as either an upper or lower nonwoven fabric layer.

[0180] Table 3 is provided for the convenience of the reader. Table 3 includes a non-exhaustive list of properties and a non-exhaustive list of corresponding values ​​for each of the properties that a particularly preferred upper nonwoven layer of this disclosure may exhibit.

[0181] [Table 3]

[0182] Final product testing Absorbent articles are tested to evaluate their ability to bend and compress in the Z direction to conform to the specific genital shape of the user. Examples 1-3 illustrate the absorbent articles described herein. Examples 1-3 are listed in Table 4a. Examples 1-3 are prepared as described below. The absorbent articles are evaluated according to the dry MD three-point bending method, absorbent article caliper, basis weight, and density method, and the Z compression method, as described herein. The results are reported as averages in Table 4b.

[0183] [Table 4] 1 Available from Xiamen Yanjan New Material Co. (China) as ATB Z87G-40. 6 Available from PFNonwovens Czech SRO (Czech Republic) as PFNZN 18G BICO8020 PHI 6. 9 Available as R73B from Xiamen Yanjan New Material Co. (China). 10 Available as Z73P-24 from Xiamen Yanjan New Material Co. (China). 11 Available from Resolute Alabama (USA) under part number 9E3-COOSABSORB S. 12 Available from Nippon Shokubai (Japan) as Acqualic L705.

[0184] The absorbent articles listed in Table 4a were produced as detailed herein. Examples 1-3 have a central absorbent zone and an outer absorbent zone as shown and described in Figure 4, with the basis weights of the inner core layer being as follows: Example 1 - Central absorbent zone: 256 gsm fluff and 102 gsm AGM; Outer absorbent zone: 206 gsm fluff and 82 gsm AGM; Example 2 - Central absorbent zone: 279 gsm fluff and 112 gsm AGM; Outer absorbent zone: 220 gsm fluff and 88 gsm AGM; and Example 3 - Central absorbent zone: 200 gsm fluff and 80 gsm AGM; Outer absorbent zone: 160 gsm fluff and 62 gsm AGM.

[0185] Specifically, the upper nonwoven layer is first introduced onto a molding drum in a laydown section and stretched into a three-dimensional pocket shape under vacuum. A homogeneous flow of cellulose and superabsorbent particulate material is deposited directly onto the upper nonwoven layer in the molding station. Before entering the molding station, the upper nonwoven is coated with a spray adhesive (Technomelt DM 9036U, 6gsm continuous meltblown spiral, 50mm wide, available from Henkel (Germany)) to provide a stronger bond between the cellulose and superabsorbent particulate material and the upper nonwoven layer without hindering the flow of liquid to the material. As it exits the laydown section, the lower nonwoven web is combined with the nonwoven carrying the homogeneous blend of cellulose and superabsorbent particulate material. The lower nonwoven fabric is pre-coated with an adhesive (Technomelt DM9036U, available from Henkel (Germany)) to allow for a perimeter seal (10gsm meltblown spiral, 20mm wide at the sides), and in the center, a 6gsm, 50mm wide continuous meltblown spiral adhesive (Technomelt DM9036U, available from Henkel (Germany)) is applied to better integrate the cellulose and superabsorbent particulate materials. Excess nonwoven material beyond the perimeter seal is removed before the top and back sheets are added. The top sheet is bonded to the absorbent core structure by applying a spray adhesive (Technomelt DM 9036U, available from Henkel (Germany), 3gsm continuous meltblown spiral, 50mm wide, 250mm long). In addition, a 12gsm polypropylene backsheet is bonded to the outer surface of the lower nonwoven fabric by applying a spray adhesive (Technomelt DM9036U, 3gsm continuous meltblown spiral, 50mm wide and 250mm long, available from Henkel (Germany)).

[0186] Examples 1-3 also have structural bonds as shown in Figures 4 and 5, with the contour shown in Figure 6. The structural bonds are applied using a heated aluminum die to form an embossed pattern in a heated hydraulic press. The structural bond embossed plate is 3.55 mm, as shown in Figure 5. 2 It has a surface area and protrusions approximately 1 mm high, and has the contour shown in Figure 6. The structural bonds are spaced according to the dimensions of the separations described above. The structural bond embossing plate is heated to 120°C and set to a compression pressure of 170 kPa. The absorbent material is placed and oriented under the heated embossing plate on the hydraulic press bottom plate, and a thin sheet of Teflon® film is placed on top of the sample before embossing to avoid melting of the top sheet fibers. The hydraulic press is activated and the sample is compressed for a residence time of 1.7 seconds to create the structural bond pattern.

[0187] Before bonding the backsheet, flexible bonding channel regions are applied to Examples 1-3 with the pattern shown in Figure 9. The flexbond channel regions are applied using a heated aluminum die to create an embossed pattern within a heated hydraulic press. The channel embossing plate has projections spaced approximately 1.5 mm apart, with a length of approximately 3 mm and a width of approximately 1.5 mm. The bond channel embossing plate is heated to 120°C and set to a compression pressure of 200 kPa. The absorbent material is placed and oriented under the heated embossing plate on the hydraulic press bottom plate, and a thin sheet of Teflon® film is placed on top of the sample before embossing to avoid melting of the topsheet fibers. The hydraulic press is activated and the sample is compressed for a residence time of 1.7 seconds to create the embossed pattern.

[0188] [Table 5]

[0189] Examples 1-3 showed calipers of 3.09 mm to 4.24 mm in the central absorbent zone and calipers of 2.53 mm to 2.86 mm in the outer absorbent zone. To create an absorbent article that fits snugly and comfortably into the outer space between the labia majora, the caliper in the central absorbent zone should be sufficiently snug to the body, while the caliper in the outer absorbent zone is thinned so that the sides can gently wrap around the left and right outer surfaces of the labia majora. Examples 1-3 exhibited a low MD flexural modulus, demonstrating that the central and outer absorbent zones are highly flexible, can bend and conform to various genital shapes with low bending resistance, and thus provide further comfort. Examples 1-3 also exhibited a Z-compression energy of 3.8 to approximately 4.4 N. mm in the central and outer absorbent zones, demonstrating that the absorbent article has high compressibility in the Z-plane. The flexibility (low modulus of elasticity) and high Z-compressibility allow the raised central absorbent zone to initially mold to the wearer's inherent shape, while also allowing it to deform and compress without discomfort during body movements such as walking, sitting, or exercising.

[0190] Combinations / Examples Paragraph A. Disposable absorbent articles, Top sheet and Back seat and, An absorbent core structure disposed between the top sheet and the back sheet, a. An upper nonwoven fabric layer containing polymer fibers and having a basis weight of approximately 35 gsm to approximately 85 gsm, b. A lower nonwoven fabric layer containing polymer fibers and having a basis weight of approximately 10 gsm to approximately 40 gsm, c. An absorbent core structure comprising an inner core layer disposed between an upper nonwoven fabric layer and a lower nonwoven fabric layer, the inner core layer comprising a mixture of cellulose fibers and superabsorbent particles, The inner core layer further comprises a central absorbent zone having a first basis weight and an outer absorbent zone having a second basis weight, wherein the outer absorbent zone substantially surrounds the central absorbent zone, and the first basis weight is greater than the second basis weight. The inner core layer has a single, integrated structure. Disposable absorbent articles having a first average density measured in the central absorbent zone and a second average density measured in the outer absorbent zone, wherein the second density is within approximately 0 to approximately 20% of the first density.

[0191] Paragraph B. The absorbent article is a disposable absorbent article as described in Paragraph A, having a caliper measuring approximately 2.5 mm to approximately 6 mm in the central absorbent zone.

[0192] Paragraph C. The first and second average densities are approximately 0.045 g / cm³. 3 ~Approx. 0.150g / cm 3 The disposable absorbent article described in paragraph A or B.

[0193] Paragraph D. The disposable absorbent article described in paragraphs A to C, wherein the central absorbent zone comprises a pair of inwardly concave longitudinal side edges, an outwardly convex front edge, and an outwardly convex rear edge.

[0194] Paragraph E. The disposable absorbent article according to paragraphs A to D, wherein the central absorbent zone comprises a front region having a first width W1, a rear region having a third width W3, and an intermediate region disposed between them having a second width W2, wherein the second width W2 is smaller than at least one of the first width W1 and the third width W3.

[0195] Paragraph F. The disposable absorbent article described in Paragraph E, wherein the third width W3 is greater than the first width W1 and the second width W2.

[0196] Paragraph G. The absorbent article is a disposable absorbent article as described in paragraphs A to F, exhibiting a Z compression energy of approximately 3.0 to approximately 8.0 N. mm, as measured in the central absorbent zone and the outer absorbent zone.

[0197] Paragraph H. Absorbent articles are measured in the central absorbent zone and the outer absorbent zone, with a tolerance of approximately 0.03 to approximately 0.18 N / mm². 2 Disposable absorbent articles as described in paragraphs A to G, showing the MD flexural modulus.

[0198] Paragraph I. The disposable absorbent article described in paragraphs A to H, wherein the central absorbent zone comprises a transition zone in which the basis weight of the inner core layer gradually decreases, and the transition zone has a width of approximately 1 mm to approximately 5 mm.

[0199] Paragraph J. The absorbent core structure has multiple structural bonding sites, and the structural bonding sites are approximately 2 mm 2 ~about 5mm 2 A disposable absorbent article as described in paragraphs A to I, having a bonding area such that the total structural bonding area of ​​the absorbent core structure is approximately 1% to approximately 4% of the absorbent core structure when measured according to the structural bonding site pattern spacing and area measurement method.

[0200] Paragraph K. The average distance between structural bonding sites is approximately 10 mm to approximately 32 mm when measured according to the structural bonding site pattern spacing and area measurement method, for the disposable absorbent article described in Paragraph J.

[0201] Paragraph L. The polymer fibers of the upper nonwoven fabric layer have a length of approximately 10 mm to approximately 100 mm, as described in paragraphs A to K of the disposable absorbent article.

[0202] Paragraph M. The polymer fibers of the upper nonwoven fabric layer have a fiber diameter of about 2.0 Dtex to about 10 Dtex, as described in paragraphs A to L of the disposable absorbent article.

[0203] Paragraph N. The upper nonwoven fabric layer has a permanent strain of approximately 0.005 to approximately 0.013 mm / mm, as described in paragraphs A to M.

[0204] Paragraph O. The upper nonwoven fabric layer measured according to the thickness-pressure method was 70 g / cm². 2Disposable absorbent articles as described in paragraphs A to N, having a thickness of approximately 0.2 mm to approximately 0.7 mm under pressure.

[0205] The dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​listed. Instead, unless otherwise specified, each such dimension is intended to mean both the listed value and the functionally equivalent range encompassing that value. For example, a dimension disclosed as "40 mm" is intended to mean "approximately 40 mm."

[0206] All documents cited herein, including cross-referenced or related patents or applications, are incorporated herein in their entirety by reference unless expressly excluded or otherwise limited. No citation of any document shall be deemed prior art to any invention disclosed or claimed herein, nor shall it be deemed to teach, suggest or disclose any such invention, either alone or in combination with any one or more other references. Furthermore, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in any document incorporated by reference, the meaning or definition given to that term in this document shall prevail.

[0207] While specific embodiments of the present invention have been illustrated and described, 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 within the scope of the invention be covered in the appended claims.

Claims

1. Disposable absorbent articles, Top sheet and Back seat and, An absorbent core structure disposed between the top sheet and the back sheet, a. An upper nonwoven fabric layer containing polymer fibers and having a basis weight of approximately 30 gsm to approximately 85 gsm, b. A lower nonwoven fabric layer containing polymer fibers and having a basis weight of approximately 10 gsm to approximately 40 gsm, c. An absorbent core structure comprising an inner core layer disposed between the upper nonwoven fabric layer and the lower nonwoven fabric layer, wherein the inner core layer contains a mixture of cellulose fibers and superabsorbent particles, The inner core layer is contoured in the longitudinal and transverse directions and is defined by a central absorbent zone and an outer absorbent zone substantially surrounding the central absorbent zone, the central absorbent zone having a first basis weight and the outer absorbent zone having a second basis weight, the first basis weight being greater than the second basis weight. The absorbent article has a first average density measured in the central absorbent zone and a second average density measured in the outer absorbent zone, wherein the first and second average densities are approximately 0.045 g / cm³. ３ ~Approx. 0.150g / cm ３ A disposable absorbent article wherein the second density is within approximately 0 to approximately 20% of the first density.

2. The disposable absorbent article according to claim 1, wherein the inner core layer has an integral structure.

3. The disposable absorbent article according to claim 1 or claim 2, wherein the central absorbent zone comprises a pair of inwardly concave longitudinal side edges, an outwardly convex front edge, and an outwardly convex rear edge.

4. The central absorbent zone comprises a front region having a first width W1, a rear region having a third width W3, and an intermediate region disposed between them having a second width W2, wherein the second width W2 is smaller than the first width W1 and the third width W3, as described in any one of claims 1 to 3.

5. The absorbent core structure comprises a plurality of structural bonding sites, and the structural bonding sites are approximately 2 mm in diameter. ２ ~about 5mm ２ A disposable absorbent article according to any one of claims 1 to 4, wherein the total structural bonding area of ​​the absorbent core structure is about 1% to about 4% of the absorbent core structure when measured according to the structural bonding site pattern spacing and area measurement method.

6. The disposable absorbent article according to claim 5, wherein the average distance between the structural bonding sites is approximately 10 mm to approximately 32 mm when measured according to the structural bonding site pattern spacing and area measurement method.

7. The disposable absorbent article according to claim 5 or claim 6, wherein the central absorbent zone substantially does not include the structural bond.

8. The upper nonwoven fabric layer has a permanent strain of approximately 0.005 to 0.013 mm / mm, and when measured according to the nonwoven fabric thickness-pressure method, it has a density of 70 g / cm². ２ A disposable absorbent article according to any one of claims 1 to 7, having a thickness of approximately 0.2 mm to approximately 0.7 mm under pressure.

9. The disposable absorbent article according to any one of claims 1 to 8, wherein the polymer fibers of the upper nonwoven fabric layer have a length of about 10 mm to about 100 mm and a fiber diameter of about 2.0 Dtex to about 10 Dtex.

10. The disposable absorbent article according to any one of claims 1 to 9, wherein the inner core layer comprises cellulose fibers in an amount of about 50% to about 85% by weight of the inner core layer, and superabsorbent particles in an amount of about 15% to about 50% by weight of the inner core layer.

11. The absorbent article has a load capacity of approximately 0.03 to approximately 0.18 N / mm², as measured in the central absorbent zone and the outer absorbent zone. ２ A disposable absorbent article according to any one of claims 1 to 10, which exhibits the MD flexural modulus.

12. The disposable absorbent article according to any one of claims 1 to 11, wherein the absorbent article has a caliper measuring about 2.5 mm to about 6 mm in the central absorbent zone.

13. The first average density and the second average density are approximately 0.045 g / cm³. ３ ~Approx. 0.150g / cm ３ A disposable absorbent article according to any one of claims 1 to 12.

14. The disposable absorbent article according to any one of claims 1 to 13, wherein the absorbent article exhibits a Z compression energy of approximately 3.0 to approximately 8.0 N. mm as measured in the central absorbent zone and the outer absorbent zone.

15. The disposable absorbent article according to any one of claims 1 to 13, wherein the central absorbent zone comprises a transition zone in which the basis weight of the inner core layer gradually decreases, and the transition zone has a width of about 1 mm to about 5 mm.

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