Absorbent Articles for Fluid Management - Patent application

Abstract

Disposable absorbent articles are disclosed having a topsheet, a backsheet, and an absorbent core structure disposed therebetween. The absorbent core structure includes an upper nonwoven layer comprising polymeric fibers, a lower nonwoven layer comprising polymeric fibers, and an inner core layer disposed between the upper and lower nonwoven layers. The inner core layer includes about 50% to about 85% cellulosic fibers by weight of the inner core layer, and superabsorbent particles. The inner core layer is contained within the nonwoven layers by substantially sealing at least the left and right regions of the upper and lower nonwoven layers. The absorbent article has a combined N.mm of about 10 to about 30 when measured according to wet and dry CD and MD 3-point bending methods. 2 and a combined total IFF+SFF value of about 20 to about 200 mg when measured according to the Acquisition Time and Rewet Method.

Description

[Technical field]

[0001] The present disclosure relates to absorbent articles having conforming features and improved elastic construction, yet still providing fluid acquisition and storage properties. [Background technology]

[0002] Absorbent articles, such as diapers, training pants, feminine pads, adult incontinence pads, etc., are widely used among consumers. Generally, such absorbent articles include a topsheet and a backsheet, with an absorbent core structure disposed therebetween. Historically, in menstrual applications, absorbent articles also include a secondary topsheet that serves to wick fluid away from the topsheet to aid in body cleansing and drying. Previous absorbent articles have relied on capillary gradient structures (each layer having increasing capillary action, i.e. density) to effectively draw fluid deep into the absorbent core and away from the body. In these structures, capillary action in the secondary topsheet to cleanse the body is combined with an underlying densified fluid storage core to effectively wick the secondary topsheet, thereby allowing the secondary topsheet to continue to absorb fluid from the topsheet. Other approaches have used lofty, relatively high caliper nonwoven secondary topsheet materials that are highly permeable, in combination with an underlying densified fluid storage core to wick fluid away from the secondary topsheet. In this construction, the secondary topsheet provides temporary fluid storage to absorb large fluid bursts, and a strong capillary gradient underneath helps to drive the fluid efficiently towards the fluid storage core.

[0003] As discussed above, these approaches rely on densifying the absorbent core to increase capillary action and move fluid away from the body and deeper into the core. However, densifying these absorbent systems comes at the expense of comfort (rigidity) and the ability of the absorbent core structure and / or absorbent article to easily conform to the wearer's unique anatomical shape.

[0004] Furthermore, the separate secondary topsheet layer in these approaches is not ideal for complex viscous fluids such as blood that must move across the boundaries between layers, as interlayer boundary effects reduce the efficiency of the fluid moving between the separate layers. Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, there is a need for absorbent articles that include absorbent core structures that provide good fluid acquisition and storage, yet are conformable and wet resilient. [Means for solving the problem]

[0006] The present disclosure solves the problem of uncomfortable and non-conforming densified absorbent articles that wet collapse and have a separate secondary topsheet layer by providing an absorbent core structure that sandwiches a liquid absorbent material between two elastic nonwoven layers, which can carry and manage mechanical stresses during use, allowing the absorbent core structure to recover its shape as the wearer compresses and deforms the absorbent article during use, as well as providing the function of the secondary topsheet to draw fluid away from the body. The absorbent core structure of the present disclosure includes a low density upper nonwoven layer that does not substantially retain fluid (but allows fluid to pass through quickly), and a liquid absorbent material that can rapidly absorb blood.

[0007] The absorbent article includes a topsheet, a backsheet, and an absorbent core structure disposed between the topsheet and the backsheet, the absorbent core structure including: (a) an upper nonwoven layer comprising polymeric fibers and having a basis weight of about 35 gsm to about 85 gsm; (b) a lower nonwoven layer comprising polymeric fibers and having a basis weight of about 10 gsm to about 40 gsm; and (c) an inner core layer disposed between the upper and lower nonwoven layers, the inner core layer comprising about 50% to about 85% by weight of cellulosic fibers and superabsorbent particles, the inner core layer being contained within the nonwoven layers by substantially sealing at least the left and right regions of the upper and lower nonwoven layers, the absorbent article being characterized by wet and dry CD and MD. It has a CD Dry Flexural Stiffness of about 10 N.mm2 to about 30 N.mm2, measured according to the 3-point bending method, and a total IFF+SFF value of about 20 mg to about 200 mg, measured according to the capture time and rewet method.

[0008] The disposable absorbent article comprises a topsheet, a backsheet, and an absorbent core structure disposed between the topsheet and the backsheet, the absorbent core structure comprising: (a) an upper nonwoven layer comprising polymeric fibers; (b) a lower nonwoven layer comprising polymeric fibers; and (c) an inner core layer disposed between the upper and lower nonwoven layers, the inner core layer comprising a mixture of cellulosic fibers and superabsorbent particles, the inner core layer being contained within the nonwoven layers by substantially sealing at least left and right regions of the upper and lower nonwoven layers, the absorbent article having a CD Dry Bending Stiffness of about 10 N.mm2 to about 30 N.mm2, as measured according to a wet and dry CD and MD 3-point bending method, and a light touch rewet of 0 to about 0.15 grams, as measured according to a light touch rewet method.

[0009] The disposable absorbent article comprises a topsheet, a backsheet, and an absorbent core structure disposed between the topsheet and the backsheet, the absorbent core structure comprising: (a) an upper nonwoven layer comprising polymeric fibers, the upper nonwoven layer having a thickness of about 0.3 mm to about 1.3 mm at a pressure of 7 g / cm2 when measured according to the Thickness-Pressure Method; and (b) a lower nonwoven layer comprising polymeric fibers, the upper nonwoven layer having a thickness of about 0.1 mm to about 1.3 mm at a pressure of 7 g / cm2 when measured according to the Thickness-Pressure Method. and (c) an absorbent core structure comprising a lower nonwoven layer having a thickness of 3 mm and a basis weight equal to or less than that of the elastic upper nonwoven layer, and an inner core layer disposed between the upper nonwoven layer and the lower nonwoven layer, wherein the inner core layer comprises cellulosic fibers of from about 125 gsm to about 400 gsm, the absorbent core structure has an average density of from about 0.045 g / cm3 to about 0.15 g / cm3, and the upper nonwoven layer has a Wet Penetration Time of less than about 4 seconds when measured according to the Wet Penetration Time Method. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram of an absorbent core structure according to the present disclosure. [Figure 2A] 1 is a diagram of an absorbent article according to the present disclosure. [Figure 2B] FIG. 2 is another view of an absorbent article according to the present disclosure. [Figure 2C] FIG. 2 is another view of an absorbent article according to the present disclosure. [Diagram 3] FIG. 2 is a cross-sectional view of an absorbent core structure. [Figure 4] FIG. 2 is a close-up view of a structure binding site according to the present disclosure. [Diagram 5] 5 is a cross-sectional view of the structure bonding portion of FIG. 4. [Figure 6] 1 is a cross-sectional view of an absorbent article according to the present disclosure. [Figure 7A] Test method configuration for wet and dry CD ultrasensitive three-point bending method. [Figure 7B] Test method configuration for wet and dry CD ultrasensitive three-point bending method. [Figure 7C] Test method configuration for wet and dry CD ultrasensitive three-point bending method. [Figure 8] Test method configuration for wet and dry bunch compression testing. [Figure 9A] Test method configuration for wet and dry bunch compression testing. [Figure 9B] Test method configuration for wet and dry bunch compression testing. [Figure 10A] 10A and 10B are exemplary graphs of bunching curves obtained from wet and dry bunching compression tests. The graphs in Figures 10A and 10B are shown to illustrate how the calculations in the method may be performed and do not represent the data described herein. [Figure 10B] 10A and 10B are exemplary graphs of bunching curves obtained from wet and dry bunching compression tests. The graphs in Figures 10A and 10B are shown to illustrate how the calculations in the method may be performed and do not represent the data described herein. [Figure 11] 1 is a test method configuration for the pore volume distribution method. [Figure 12A] A schematic cross-sectional view of a measurement apparatus configuration used in the transmittance measurement methods described herein, taken through a vertical plane that bisects the illustrated fluid container 6010. [Figure 12B] FIG. 12b is a diagram of the measurement setup shown in FIG. 12a, shown with added elements in preparation for the start of the measurement procedure. [Figure 12C] FIG. 12b is a diagram of the measurement setup shown in FIG. 12b, shown after the start of the measurement procedure. [Figure 13A] FIG. 2 is a perspective view of a sample weight used in the transmittance measurement method described herein. [Figure 13B] FIG. 13b is a top view of the sample weight shown in FIG. 13a. [Figure 13C] FIG. 13b is a vertical cross-sectional view of the sample weight shown in FIG. 13a. [Figure 14] FIG. 2 is a top view of a sample support used in the transmittance measurement methods described herein. [Figure 15] FIG. 2 is a top view of a strikethrough plate used in the acquisition time and rewet method described herein. [Figure 16] FIG. 2 is a bottom view of a strikethrough plate used in the capture time and rewet method described herein. [Figure 17A] 17A is a cross-sectional view of a penetration plate used in the capture time and rewet method described herein, taken along the plane defined by the z-direction and line 17A-17A shown in FIG. [Figure 17B] FIG. 17B is a cross-sectional view along the plane defined by the z-direction and line 17B-17B shown in FIG. 15 of a penetration plate used in the capture time and rewet method described herein. [Figure 18] 1 is a graph showing CD Dry Bending Stiffness in N.mm2 versus Light Touch Rewet in grams (g) for several measured samples. [Figure 19] 1 is a graph showing total IFF+SFF in milligrams (mg) versus CD Dry Flexural Stiffness in N.mm2 for multiple measured samples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] As used herein, "disposable absorbent article" or "absorbent article" is intended to refer to articles such as diapers, training pants, diaper pants, refastenable pants, adult incontinence pads, adult incontinence pants, feminine hygiene pads, cleaning pads, etc., each of which is intended to be discarded after use.

[0012] As used herein, "absorbent core structure" is intended to refer to an upper nonwoven layer, a lower nonwoven layer, and an inner core layer disposed between the upper and lower nonwoven layers.

[0013] As used herein, "hydrophilic" and "hydrophobic" have their well-established meanings in the art with respect to the contact angle of water on a material surface. Thus, a material having a water contact angle of more than about 90 degrees is considered hydrophobic, and a material having a water contact angle of less than about 90 degrees is considered hydrophilic. A composition that is hydrophobic increases the contact angle of water on the surface of the material, whereas a composition that is hydrophilic decreases the contact angle of water on the surface of the material. Notwithstanding the above, reference to relative hydrophobicity or hydrophilicity between a material and a composition, between two materials, and / or between two compositions does not mean that the material or composition is hydrophobic or hydrophilic. For example, the composition may be more hydrophobic than the 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, the composition may be more hydrophilic than the material. In this case, neither the composition nor the material may be hydrophilic. However, the contact angle exhibited by the composition is less than that exhibited by the material.

[0014] As used herein, "machine direction" refers to the direction in which a web runs through an absorbent article conversion process. For simplicity, it may be referred to as "MD."

[0015] As used herein, "cross machine direction" refers to the direction perpendicular to the MD, which for simplicity is sometimes referred to as the "CD."

[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 resume its original pre-compressed shape when such force is removed. In some aspects, the upper and / or lower nonwoven layers described herein may be elastic.

[0017] As used herein, "wearer-facing" (sometimes referred to herein as body-facing) and "outer-facing" (sometimes referred to herein as garment-facing) each refer to the relative location of an element or a surface of an element or group of elements. "Wear-facing" means that the element or surface is closer to the wearer during wear than any other element or surface. "Outer-facing" means that the element or surface is farther away from the wearer during wear (i.e., the element or surface is closer to the wearer's garment, which may be worn over the absorbent article), than any other element or surface.

[0018] It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification includes every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification includes every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

[0019] The disposable absorbent articles described herein may include a topsheet, a backsheet, and an absorbent core structure disposed therebetween. The absorbent core structure may include an upper nonwoven layer and a lower nonwoven layer, with the inner core layer disposed between the upper and lower nonwoven layers. The inner core layer may be contained within the nonwoven layers by substantially sealing at least the left and right regions of the upper and lower nonwoven layers at a perimeter seal. In some configurations, the upper and lower nonwoven layers may be joined with a perimeter seal that extends around the entire perimeter of the inner core layer.

[0020] In some aspects, the disposable absorbent article may include the following structures (from the wearer-facing surface to the outer-facing surface): a topsheet, an upper nonwoven layer, an inner core layer, a lower nonwoven layer, and a backsheet. In some aspects, the topsheet may be in direct contact with the upper nonwoven layer, the upper nonwoven layer may be in direct contact with the inner core layer, and / or the inner core layer may be in direct contact with the lower nonwoven layer. By "direct contact" is meant that there is no additional intermediate component layer between the respective layers in direct contact. However, it is not excluded that an adhesive material may be disposed between at least a portion of the aforementioned layers.

[0021] As shown in Figures 1 and 3, the absorbent core structure 10 may include an upper nonwoven layer 210 and a lower nonwoven layer 220 (collectively referred to herein as upper and lower nonwoven layers or upper and lower nonwovens) and an inner core layer 200 disposed between the upper nonwoven layer 210 and the lower nonwoven layer 220. The absorbent core structure 10 may include the inner core layer 200 comprising a liquid absorbent material. Without being limited by theory, it is believed that the absorbent core structure may regain its shape in a dry or wet state over a range of body movements and stresses. The liquid absorbent material may comprise a matrix comprising cellulose fibers and superabsorbent particles (sometimes referred to herein as "feather / AGM"). The upper nonwoven layer 210 and the lower nonwoven layer 220 may be joined together at a perimeter seal 230 using adhesives or other conventional bonding methods including, but not limited to, ultrasonic bonding, melt bonding, pressure bonding, and combinations thereof.

[0022] The flexibility and / or resilience of the absorbent core structure results in an absorbent article that comfortably conforms to the wearer's anatomical shape while efficiently managing fluids as they exit the body. This can unexpectedly be achieved without typical densification stiffening (for wet integrity) by utilizing elastic upper and lower nonwovens composed of elastic polymers located above and below the loosely packed fluff / AGM matrix of the inner core layer. This absorbent core structure is able to carry structural loads and recover shape without physically stiffening or losing desired structural properties when the absorbent core structure becomes wet.

[0023] When the selected elastic upper and lower nonwovens 210, 220 are positioned above and below the fluff / AGM matrix of the inner core layer and bonded to and around the fluff / AGM matrix, it is believed that wet integrity / shape stability in the cellulose-rich absorbent core structure occurs without substantial densification and stiffening. The upper and lower nonwovens need sufficient recovery force to return the fluff / AGM matrix to its original state or stable fiber orientation after compression. Wrapping or encapsulating the cellulose-rich fluff core with a simple cellulose tissue or less elastic nonwoven material may not provide sufficient recovery energy to recover the shape during use, especially when wet. The structural wet elastic nonwovens detailed herein may exhibit recovery energy after compression that is sufficient to recover the cellulose-rich fiber matrix and is selected to provide high compression recovery with relatively low stiffness in both dry and wet conditions.

[0024] It has further been found that by incorporating fluid handling functionality into the upper nonwoven layer, absorbent core structures can be made without the need for a separate secondary topsheet layer.By directly integrating the upper nonwoven layer and the fluff / AGM matrix during manufacture (as opposed to combining with a separate secondary topsheet layer and a separately wrapped core), the interlayer boundary effect that reduces the efficiency of fluid transfer can be avoided.As a result, fluid drainage from the upper nonwoven layer to the lower fluff / AGM matrix can be achieved without the need for densification.

[0025] A suitable upper nonwoven layer may have a basis weight of about 30 gms to about 85 gms, or about 35 gms to about 70 gsm, or about 40 gms to about 60 gsm. The upper nonwoven layer may have a tensile stiffness of about 0.3 N / mm to about 1.6 N / mm. The upper nonwoven layer may have a breaking strain of greater than about 10%, or about 10% to about 50%, or about 20% to about 40%. The upper nonwoven layer may have a permanent set of about 0.005 to about 0.013 mm / mm, or 0.005 to about 0.0090 mm / mm.

[0026] Suitable lower nonwoven layers may have a basis weight of about 10 to about 40 gsm, or about 15 to about 20 gsm. The lower nonwoven layer may have a tensile stiffness of about 0.2 N / mm to about 1.6 N / mm. The lower nonwoven layer may have a breaking strain of greater than about 10%, or about 10% to about 50%, or about 20% to about 40%. The lower nonwoven layer may have a permanent set of about 0.005 to about 0.013 mm / mm.

[0027] The upper and lower nonwoven layers may comprise polymeric fibers. Suitable upper and lower nonwoven fibers may be selected from PET (polyethylene terephthalate), PP (polypropylene), BiCo (bicomponent fibers) selected from PE / PP (PE sheath and PP core) and / or PE / PET (PE sheath PET core), PLA (polylactic acid), and combinations thereof.

[0028] Suitable upper nonwoven fabrics may include about 60% to about 100%, or about 70% to about 100% synthetic fibers, and about 0% to about 40%, or about 0% to about 30% regenerated cellulose fibers, such as rayon and / or viscose.

[0029] The upper nonwoven layer may comprise fibers having a staple length of greater than about 10 mm, or greater than about 25 mm, or from about 10 mm to about 100 mm, or from about 20 mm to about 75 mm, or from about 25 mm to about 50 mm. The upper nonwoven layer may comprise fibers having a fiber diameter of about 1.3 dTex to about 10 dTex, or from about 1.3 dTex to about 6.0 dTex, or from about 2.0 dTex to about 5.0 dTex. In some configurations, the upper nonwoven layer may comprise fibers that are a blend of staple fibers having a fiber diameter of about 2.0 dTex to about 10 dTex.

[0030] The lower nonwoven layer may comprise fibers having a length greater than about 10 mm, or greater than about 25 mm, or from about 10 mm to about 100 mm, or from about 20 mm to about 75 mm, or from about 25 mm to about 50 mm. In some configurations, the lower nonwoven layer may comprise continuous fibers. The lower nonwoven layer may comprise fibers having a fiber diameter of about 1.3 DTex to about 5.0 DTex, or from about 1.3 DTex to about 3.3 DTex, or from about 1.3 DTex to about 2.2 DTex, or from about 2.0 DTex to about 10 DTex. In some configurations, the lower nonwoven layer may comprise fibers, the fibers being a blend of fibers having a fiber diameter of about 0.1 DTex to about 6.0 DTex.

[0031] In some configurations, a suitable fiber combination may include upper nonwoven polymeric fibers having a diameter of about 2.0 DTex to about 10 DTex and lower nonwoven polymeric fibers having a diameter of about 1.7 DTex to about 5 DTex. In some configurations, a suitable fiber combination may include upper nonwoven polymeric fibers having a diameter of about 1.3 DTex to about 2.2 DTex and lower nonwoven polymeric fibers having a diameter of about 1.7 DTex to about 5 DTex.

[0032] 2A and 3, an absorbent article 20 includes an absorbent core structure 10 including an upper nonwoven layer 210 and a lower nonwoven layer 220 with an inner core layer 200 disposed therebetween. Figure 2A is a top view of the absorbent article 20 with the topsheet removed for simplicity. Figure 3 is a cross-sectional view of the absorbent core structure 10 of Figure 10.

[0033] The absorbent article 20 and the absorbent core structure 10 each include a front region 21, a rear region 23, and a middle region 22 disposed intermediate the front and rear regions. The upper nonwoven layer 210 may include a left region 210a and a right region 210b, and the lower nonwoven layer 220 may include a left region 220a and a right region 220b. The upper and lower nonwoven layers 210, 220 may extend outwardly from the inner core layer perimeter 200a and may be joined together to form a perimeter seal 230. In some configurations, the entire inner core layer 200 may be located inside the perimeter seal 230. The perimeter seal 230 may help seal the liquid absorbent material of the inner core layer 200 inside the upper nonwoven layer 210 and the lower nonwoven layer 220. The perimeter seal 230 may comprise at least a first lateral seal area 231 and a second lateral seal area 231'. In some configurations, the perimeter seal 230 may further comprise a front perimeter seal area 232 and / or a rear perimeter seal area 233. In some configurations, the perimeter seal 230 may extend around the entire inner core layer perimeter 200a. In some configurations, the perimeter seal 230 may extend only partially around the inner core layer perimeter 200a.

[0034] In some configurations, the inner core layer 200 may be contained within the upper nonwoven layer 210 and the lower nonwoven layer 220 by substantially sealing at least the left regions 210a, 220a and right 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 contained within the upper nonwoven layer 210 and the lower nonwoven layer 220 by sealing at least a portion of the left regions 210a, 220a and right regions 210b, 220b of the upper nonwoven layer 210 and the lower nonwoven layer 220.

[0035] The perimeter seal 230 may have a seal width WS of about 1 mm to about 10 mm, or about 2 mm to about 8 mm, or about 3 mm to 6 mm. The seal width WS may be uniform or may vary around the circumference of the inner core layer.

[0036] In some configurations, the absorbent article 20 may also include a front end seal 234 located at the front end region 227 of the absorbent article and a rear end seal 235 located at the rear end region 228 of the absorbent article. The front end seal 234 and / or the rear end seal 235 may seal the topsheet, the upper nonwoven layer, the lower nonwoven layer, and the backsheet together. In some configurations, the front end seal 234 and / or the rear end seal 235 may seal the topsheet and the backsheet. In some configurations, the front end seal 234 and / or the rear end seal 235 may be a crimp seal.

[0037] In some configurations, the upper nonwoven layer 210 and the lower nonwoven layer 220 may be separate materials that may be cut to approximately the size and shape of the inner core layer 200 to fit between the topsheet and the backsheet, but may not extend substantially 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 shaped, meaning that they are non-rectangular. In some configurations, the upper nonwoven layer 210 and / or the lower nonwoven layer 220 may extend from the front end region 227 of the absorbent article to the rear end region 228 of the absorbent article.

[0038] The nonwoven layers containing polymeric fibers may retain their shape when wet and resist plasticization when attached to the fluff / AGM matrix through application of a core structure adhesive applied directly to either the fluff / AGM matrix or the elastic nonwoven layers via a conventional spray coating application selected to achieve bonding but not impede fluid flow to the fluff / AGM matrix. In addition, the upper and lower nonwoven layers 210, 220 may have at least a partial perimeter seal 230 to better connect the upper and lower nonwoven layers 210, 220 with the inner core layer 200 contained within the upper and lower nonwoven layers 210, 220. The perimeter seal 230 may be located in at least the middle region 22 of the absorbent article and / or absorbent core structure. Without being bound by theory, it is believed that the middle region 22 (located between the wearer's thighs during use) may be subjected to the most frequent and / or highest forces during use. It has been found that when the upper and lower nonwoven layers are bonded by conventional means (e.g., adhesives, polymer welding, and / or strong physical entanglement), the presence of at least partial perimeter seals on the left and right regions of the upper and lower nonwoven layers outside the fluff / AGM matrix can help ensure that the upper and lower nonwovens maintain their structural function without separating during physical deformation and limit potential integrity and bunching problems. Forming a perimeter seal can allow any excess nonwoven material to be removed to allow the absorbent core structure to mold to the inner thigh shape.

[0039] Suitable upper and lower nonwoven 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 forces (loads) and low bending energy. Inappropriate materials bend easily but do not have sufficient recovery energy and therefore retain the deformed bent state due to insufficient recovery energy. Suitable materials have sufficient energy to recover to their initial pre-bend state. Materials with sufficient bending recovery energy can be considered elastic upper and lower nonwoven layers.

[0040] As mentioned above, the upper and lower nonwovens include polymeric fibers. Polymeric fibers may be included to help provide structural integrity to the upper and lower nonwovens. Polymeric fibers can help increase the structural integrity of the upper and lower nonwovens in both the machine direction (MD) and cross machine direction (CD), which can facilitate web manipulation during processing of the upper and lower nonwovens for incorporation into a pad.

[0041] Polymer fibers of any suitable composition can be selected. Some examples of suitable polymer fibers can include bicomponent fibers including polyethylene (PE) and polyethylene terephthalate (PET) components or polyethylene terephthalate and copolyethylene terephthalate components. The components of the bicomponent fiber can be arranged in a sheath-core configuration, a side-by-side configuration, an eccentric sheath-core arrangement, a trilobal configuration, or other suitable configuration. In some configurations, the polymer fibers can include bicomponent fibers having PE / PET components arranged in a concentric sheath-core configuration, where the polyethylene component forms the sheath.

[0042] While other materials may be useful in creating an elastic structure, the stiffness of the PET core component in the sheath-core fiber configuration is believed to be useful in imparting elasticity to the upper and lower nonwovens. In a synergistic combination, a PE sheath component having a lower melting temperature than the PET core component can be utilized to provide inter-fiber melt / fusion bonds provided by heat treatment of the precursor batt. This can help provide tensile strength to the web in both MD and CD. Such inter-fiber bonds can help reduce inter-fiber slippage, thereby further contributing to impart shape stability and elasticity to the material, even when the material is wet.

[0043] When a relatively high weight fraction of polymer fibers is included, more connections can be formed in the structure through heat treatment. However, too many connection points can impart more stiffness to the upper and lower nonwovens than may be desired. For this reason, selecting the weight fraction of polymer fibers can involve prioritizing and balancing the competing needs for stiffness and softness in the upper and lower nonwovens.

[0044] As mentioned above, the upper and lower nonwovens may further include polymer fibers that increase the elasticity of the upper and lower nonwovens. The elastic polymer fibers can help the upper and lower nonwovens maintain permeability and compression recovery. In some configurations, the upper and lower nonwovens may include elastic polymer fibers with various cross-sections, for example, round and hollow spiral, and / or may include elastic fibers with various sizes.

[0045] The polymer fibers may be elastic and may be spun from any suitable thermoplastic, such as polypropylene (PP), polyethylene terephthalate (PET), or other suitable thermoplastics known in the art. The average staple length of the elastic polymer fibers may range from about 10 mm or more, about 20 mm to about 100 mm, or 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 helical, wavy oval, trefoil, wavy ribbon, and others. Furthermore, the elastic polymer fibers may be solid, hollow, or multi-hollow. The elastic polymer fibers may be solid and round in shape. In other suitable examples, the elastic polymer fibers may include polyester / coextruded polyester fibers. Other suitable examples of the elastic polymer fibers may include bicomponent fibers, such as polyethylene / polypropylene, polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate bicomponent fibers. These bicomponent fibers may have a sheath / core configuration.

[0046] The elastic polymer fibers may be polyethylene terephthalate (PET) fibers or other suitable non-cellulosic fibers known in the art. The PET fibers may be imparted with any suitable structure or shape. For example, the PET fibers may be circular or have other shapes such as helical, wavy oval, trefoil, wavy ribbon, hollow helix, and the like. The PET fibers may be solid, hollow, or multi-hollow. In one particular example, the PET fibers may be hollow in cross section and may have a curled or helical configuration along their length. Optionally, the elastic polymer fibers may be helically crimped or flat crimped. The elastic polymer fibers may have a crimp value of about 4 to about 12 crimps per 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 elastomeric polymer fibers are available from Wellman, Inc. (Ireland) under the trade names H1311 and T5974. Other examples of suitable elastomeric polymer fibers are disclosed in U.S. Patent No. 7,767,598.

[0047] The stiffening polymer fiber and the elastic polymer fiber should be carefully selected. For example, the chemical nature of the components forming the stiffening polymer fiber and the elastic polymer fiber may be similar, but the elastic polymer fiber must be selected so that the melting point of its component material is higher than the melting point of the bondable component of the stiffening polymer fiber. Otherwise, during heat treatment, the elastic polymer fiber may bond to the stiffening polymer fiber (or vice versa), forming an excessively rigid structure. To avoid this risk when the stiffening polymer fiber includes bicomponent fibers, for example, core-sheath component fibers with a sheath component with a relatively low melting temperature where melt bonding occurs, the elastic polymer fiber may include only the core component chemical, which may be a polymer with a relatively high melting temperature.

[0048] Nonwoven performance can be influenced by the combination of the choice of nonwoven fiber polymer, fiber properties, and how the fibers are arranged or connected. The choice of nonwoven can affect the ability of the absorbent article to recover its shape following the compressive, bending, and elongation (stretching) forces that occur during use with body movement. If the fibers are short (less than about 10 mm), they are likely to irreversibly rearrange under elongation and compression forces. Rearrangement of the fibers in the fiber matrix (changing their orientation / state) will dissipate tensile (stretching) or compressive forces, so that the energy used to affect the deformation is not available for recovery to the original shape. Longer fiber networks (typically greater than about 10 mm but less than about 100 mm) can dissipate tensile / compressive forces typical of body movement along the length of the fiber and across the structure. As a result, the applied force is available to restore the structure to its original state. Longer fiber networks composed of finer fibers (less than about 15 to about 20 microns and about 2.0 DTex) stretch and compress more easily. As a result, the fluff / AGM structure can be deformed 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 from about 2.0 DTex to greater than about 10 DTex, are flexible under the force of the body, but provide sufficient fiber and web recovery energy to return the structure to its original state.

[0049] From a structural standpoint, fiber configuration in filament networks can affect the performance of absorbent articles containing these nonwovens. Filament webs of thicker fibers are typically bulkier than traditional thin spunbond nonwoven webs, which are composed of continuous fine fibers that are closely spaced and physically bonded together. By making a web of thicker fibers arranged in a more randomized orientation, such as can be achieved through carding, hydroentangling, and needling, the fibers can only temporarily adjust their configuration (spaces between fibers exist due to their arrangement) and carry / store deformation forces, and this energy can be used to restore the structure shape.

[0050] Additionally, finer (less than about 2.0 Dtex) synthetic fibers, such as BiCo and PP fibers commonly found in spunbond, are closely spaced, aligned relatively parallel, and intimately bonded to one another. The bonded fibers in these spunbond webs are interconnected (at closely spaced point bonds) such that upon pulling (stretching), the fibers at the polymer level are forced to stretch, which permanently rearranges the polymer chains within the fibers, such that the fibers themselves remain potentially permanently stretched (permanently strained) and can no longer recover to their original state.

[0051] In some configurations, the upper nonwoven layer may substantially absorb fluid while minimizing the spreading of fluid on the surface. Without being limited by theory, it is believed that this can be achieved by a combination of highly wettable materials with open fiber structure best matched with thicker (>2.0 DTex) staple nonwoven fibers. In some embodiments, the upper nonwoven layer may have a Wet Penetration Time of less than about 4 seconds, or from about 0.1 to about 4 seconds, or from about 0.5 to about 3 seconds, or from about 0.75 to about 2.5 seconds, as measured according to the Wet Penetration Time method described herein.

[0052] The upper nonwoven layer has a pore volume distribution (PVD) of about 200 mJ / m2 as measured according to the Pore Volume Distribution (PVD) method described herein.2 ~about 400mJ / m 2 , or about 225 mJ / m 2 ~Approx. 375mJ / m 2 The capillary action potential (CWP) may be

[0053] The upper nonwoven layer may have a permeability value of from about 150 darcy to about 1000 darcy, or from about 250 darcy to about 990 darcy, when measured according to the Permeability Measurement Method described below.

[0054] In some embodiments, the polymeric fibers in the upper nonwoven layer and the polymeric fibers in the lower nonwoven layer can be different, hi some embodiments, the polymeric fibers in the upper nonwoven layer and the polymeric fibers in the lower nonwoven layer can be the same.

[0055] In some configurations, the upper and / or lower nonwovens may be air-through bonded carded nonwovens, high loft nonwovens, hydroentangled nonwovens, and combinations thereof. The upper nonwoven may be air-through bonded or hydroentangled. The lower nonwoven may be air-through bonded or hydroentangled.

[0056] Examples of suitable nonwoven materials may include, but are not limited to, the following materials: (i) 40 gsm carded elastic nonwoven material (material code; ATB Z87G-40-90) manufactured by Yanjan China, which is a carded nonwoven composed of a blend of 60% 2DTex and 40% 4DTex BiCo (PE / PET) fibers. These fibers are bonded (by ATB = "hot" air bonding) to form a wet elastic network. The basis weight of the material is 40 gsm and its caliper (under 7 kPa) is about 0.9 mm. Without being bound by theory, it is believed that due to the presence of 4DTex BiCo fibers and the inter-fiber bonded BiCo network, the material has low permanent set (less than about 0.013 mm / mm) and sufficient dry recovery energy (about 0.03 N) in wet and dry CD hypersensitive 3-point bending tests. *The material has a high void volume to hold fluid jets and is highly permeable. The material is compressible, so its initial thickness is high under body pressure (70 g / m2), but can be compressed, allowing for more efficient fluid movement from the topsheet through the material to the inner core layer. (ii) 55 gsm elastic spunlace material (material code: 53FC041001) manufactured by Sandler Germany, which is a hydroentangled nonwoven fabric produced by a carding process (like the nonwovens described above) followed by hydroentanglement using an elevated drying process (as described in US Patent Publication No. 2020 / 0315873(A1)) that produces both entangled and BiCo-bonded elastic networks. It contains a fiber blend of 30% 10DTex HS-PET, 50% 2.2DTex BiCo (PE / PET), and 20% 1.3DTex rayon. Therefore, this material exhibits low permanent deformation (less than about 0.013 mm / mm) and sufficient dry recovery energy (about 0.03 N) in wet and dry CD ultrasensitive three-point bending tests. *(greater than mm). The presence of high levels of high Dtex fibers can help the structure to remain open (permeable) and have enough void volume (thickness) to hold the blowout. The presence of rayon can improve capillarity so that the material can provide a balance between capillarity and permeability without having too much capillarity to compete with the fluff / AGM matrix for fluids, (iii) 50gsm elastic spunlace material (material code: 53FC041005 opt82) manufactured by Sandler Germany, which is a hydroentangled nonwoven fabric manufactured by a carding process (like the nonwovens mentioned above) followed by hydroentanglement by elevated drying process (as described in US Patent Publication No. 2020 0315873(A1)) that creates both entangled and BiCo bonded elastic networks. It contains a fiber blend of 60% 5.8Dtex BiCo (PE / PET), 20% 3.3Dtex trilobal "structured" rayon, and 20% 1.3Dtex rayon. Thus, this material exhibits low permanent set (less than about 0.013 mm / mm) and sufficient dry recovery energy (about 0.03 N) in wet and dry CD ultrasensitive 3-point bending tests. * This material has 40% rayon which may soften when wet, but the use of structural trilobal rayon fibers may aid in structural stability in wet conditions. The presence of structural trilobal rayon may also result in higher levels of capillarity due to the higher surface area to volume of the trilobal rayon shape while also achieving high levels of permeability.

[0057] In combination with controlling pore size, volume, and number by selecting the appropriate fiber size, basis weight, and degree of compaction, manufacturers may wish to select fiber components to obtain a particular surface chemical property(s), for example, fibers with hydrophobic surfaces, hydrophilic surfaces, or blends of different fibers and / or fibers with z-directional layering or gradients thereof. Fibers with hydrophilic surfaces tend to absorb and move the aqueous components of menstrual fluid along them in a manner that promotes wicking and rapid fluid acquisition after discharge. However, at the same time, the predominance of hydrophilic fiber surfaces in the topsheet may increase the tendency of the topsheet to reacquire fluid from the absorbent components underneath (rewet), which may cause an undesirable wet feel 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 wicking, but also resisting rewet. Manufacturers may wish to strike the right balance in selecting component fibers having hydrophilic surfaces, fibers having hydrophobic surfaces, or blends and / or z-direction layering thereof in combination with fiber size, fiber reinforcement level, and resulting topsheet pore size, volume, and number for any particular product design.

[0058] The inner core layer is manufactured by the air-laying process. A stream of cellulose fibers and AGM is carried by a fast moving air stream and deposited in a three-dimensional shaped pocket on a rotating molding drum with a vacuum underneath to draw the cellulose and AGM into the pocket in the laydown station. This forming pocket provides the actual physical shape of the absorbent core structure. An upper or lower nonwoven may be introduced onto the forming drum first, and under vacuum the upper or lower nonwoven is stretched into a three-dimensional pocket shape. In this case, a stream of cellulose and AGM material is deposited directly onto the upper (or lower) nonwoven material at the forming station. Before entering the forming station, the nonwoven is coated with an adhesive to more firmly connect the cellulose and AGM to the nonwoven layer. Upon exiting the laydown section, a second remaining nonwoven layer is combined with the nonwoven carrying the cellulose and AGM layers exiting the laydown section. This second remaining nonwoven (either the upper or lower nonwoven depending on which nonwoven passes through the laydown section) is pre-coated with an adhesive to allow for a perimeter seal and to better integrate the cellulose and AGM without impeding the flow of liquid to the cellulose and AGM matrix. In an alternative approach, the nonwoven is not introduced to the forming station first, and the cellulose and AGM mass is held on the forming drum under vacuum until it is discharged onto either the upper or lower nonwoven layer that has been coated with adhesive as detailed above, and then sealed with the second remaining nonwoven to form the absorbent core structure. The width of the upper and lower nonwoven webs is typically selected to be wider than the maximum width of the formed cellulose and AGM matrix, thereby allowing for an effective perimeter seal where the two nonwovens connect, at least at the left-most and right-most sides of the absorbent core structure.

[0059] The inner core layer may comprise any of a wide variety of liquid absorbent materials commonly used in absorbent articles, such as ground wood pulp, commonly referred to as airfelt. One suitable absorbent core material is an airfelt material available from Weyerhaeuser Company (Washington, USA) under the code number FR516. Examples of other suitable liquid absorbent materials for use in the absorbent core may include creped cellulose wadding, meltblown polymers including coform, chemically stiffened, modified, or crosslinked cellulose fibers, synthetic fibers such as crimped polyester fibers, peat moss, cotton, bamboo, absorbent polymer materials, or any equivalent material or combination of materials, or mixtures thereof.

[0060] Absorbent polymer materials for use in absorbent articles typically comprise water-insoluble, water-swellable, hydrogel-forming crosslinked absorbent polymers capable of absorbing large amounts of liquid and retaining such absorbed liquid under moderate pressure.

[0061] The absorbent polymer material for the absorbent core according to the present disclosure may comprise superabsorbent particles, also known as "superabsorbent materials" or "absorbent gelling materials". The absorbent polymer material, typically in particle form, may be selected from among polyacrylates and polyacrylate-based materials, such as partially neutralized cross-linked polyacrylates. The term "particles" refers to granules, fibers, flakes, spheres, powders, platelets, and other shapes and forms known to those skilled in the art of superabsorbent particles. In some aspects, the superabsorbent particles may be in the shape of fibers, i.e., elongated, acicular superabsorbent particles.

[0062] In some configurations, the absorbent polymer material may be a superabsorbent particle having an average particle size of about 30μ to about 1000μ, preferably about 50μ to about 800μ, more preferably about 80μ to about 700μ, and most preferably about 100μ to about 600μ in a dry state. Smaller particle sizes within the above preferred ranges may be advantageous as they provide optimal performance. Smaller particle sizes, for example less than about 100μ, for example about 30μ to about 100μ, may be beneficial for fluid handling capabilities, and such small particle sizes must be effectively and stably contained within the structure of the absorbent article. "Particle size" as used herein means the weighted average of the smallest dimension of the individual particles. The average particle size of a material in particulate form, i.e., for example, an absorbent polymer material, may be determined, for example, by dry sieving analysis, as known in the art. Optical methods, for example, based on light scattering and image analysis techniques, may also be used.

[0063] According to the present disclosure, typically, the absorbent polymer material, for example in particle form, can be selected from among the polyacrylate-based polymers described in PCT Patent Application WO 07 / 047598, which are very slightly crosslinked or substantially not crosslinked polyacrylate-based materials. Suitable superabsorbent particles are also described in US Pat. No. 9,622,916.

[0064] In some configurations, the inner core layer may comprise from about 125 gsm to about 400 gsm, or from about 150 gsm to about 350 gsm, or from about 175 gsm to about 325 gsm of liquid-absorbent material.

[0065] In some configurations, the inner core layer may include cellulose fibers and superabsorbent particles. The inner core layer may include about 50% to about 85%, or about 55% to about 80%, or about 60% to about 75% cellulose fibers by weight of the inner core layer. The inner core layer may include about 10% to about 50%, or about 15% to about 50%, or about 20% to about 40%, or about 25% to about 35% superabsorbent particles by weight of the inner core layer. Preferably, the inner core layer may include about 125 gsm to about 400 gsm cellulose fibers. The inner core layer may include about 20 gsm to about 100 gsm superabsorbent particles.

[0066] In some configurations, the inner core layer may comprise about 50% to about 85% cellulosic fibers and about 15% to about 50% superabsorbent particles. The resulting absorbent core structure has a density of about 0.045 g / cm 3 ~Approx. 0.15g / cm 3 , or 0.045 g / cm 3 ~0.12g / cm 3 The absorbent article may have an average density of about 0.045 g / cm 3 ~Approx. 0.16g / cm 3 The material may have an average density of

[0067] The absorbent core structure may be compressed and recover to its original shape after the compression step. A suitable absorbent core structure requires low force (low resistance) to compress and the structure can recover its shape when cyclically compressed by the user and released with various body movements. To achieve this, the structure maintains sufficient recovery energy following multiple cyclic compressions. Without sufficient recovery energy, the structure remains in a compressed, clumped state with insufficient force (stored energy) to recover.

[0068] As shown in Figures 1, 2A-2C, 4, and 5, the absorbent core structure may include a plurality of structural bond sites 15. The structural bond sites 15 may be symmetrical and / or asymmetrical and may be any shape, including but not limited to circular, oval, heart, diamond, triangular, star, and / or X-shaped. The structural bond sites 15 may be on the absorbent article and / or on the absorbent core structure. In some configurations, the structural bond sites are spaced apart from each other by about 2 mm. 2 ~about 5mm 2 In some configurations, the total structural bond area may be about 0.5% to about 5%, or about 0.75% to about 4.5%, or about 1% to about 4% of the absorbent core structure when measured according to the structural bond site pattern spacing and area measurement method. In some configurations, the total structural bond area may be about 1% to about 4% of the absorbent article when measured according to the structural bond site pattern spacing and area measurement method. The average distance between the structural bond sites may be about 10 mm to about 32 mm. In some configurations, the average distance between the structural bond sites may be greater than about 20 mm. In some configurations, the structural bond sites may have a maximum width of about 1 mm to about 6 mm, or about 1.5 mm to about 5 mm, or about 2 mm to about 4 mm. Without being limited by theory, it is believed that the average distance between the structural bond sites and / or the size of the structural bond sites may help maintain the structural integrity of the absorbent core structure without creating undesirable stiffness that may inhibit the ability of the absorbent article to conform to the body.

[0069] In some configurations, the structural bond sites may be distributed throughout the absorbent article and / or absorbent core structure, or may be clustered in regions of the absorbent article and / or absorbent core structure. In some configurations, the structural bond sites may be clustered in an intermediate region 22 of the absorbent article and / or absorbent core structure. In some configurations, the intermediate region 22 of the absorbent article and / or absorbent core structure may be free of structural bond sites, or may be surrounded by areas of structural bond sites and / or embossing. In some configurations, the absorbent article may include one or more flexible bond channel regions 160, which may be a continuous depression and / or a series of individually compressed closely spaced embossments.

[0070] In some configurations, the structural bond sites 15 may join the topsheet 110, the upper nonwoven layer 210, the absorbent core structure 10, and the lower nonwoven layer 220. In some configurations, the structural bond sites 15 may join the upper nonwoven layer 210, the absorbent core structure 10, and the lower nonwoven layer 220.

[0071] A suitable absorbent article and / or absorbent core structure may include an upper nonwoven layer and a lower nonwoven layer that are closer to each other in the Z-direction at the structural bond sites, but are not fused to each other. Because these structural bond sites are not fused to each other, they may not be permanent in nature, but rather may intermingle materials within the structural bond sites. In some configurations, the structural bond sites may be substantially free of fused bonds.

[0072] The shape of the structural binding site can be any shape, although preferred shapes may be more elaborate shapes such as asymmetric shapes (versus simple dots).

[0073] The absorbent article 20 may be elastic and conformable, providing an excellent in-use experience without bunching and / or compression. The absorbent article may be subjected to body forces and be able to recover to its original state. The absorbent article has a compressive strength of about 0.07 to 0.30 N / mm2, measured by wet and dry CD and MD 3-point bending. 2 , or about 0.10 to about 0.25 N / mm 2 , or about 0.10 to about 0.20 N / mm 2 The CD dry modulus may be

[0074] The absorbent article may have a dry caliper, measured according to the wet and dry CD and MD three-point method, of about 2.0 mm to about 6.0 mm, or about 2.0 mm to about 4.5 mm, or about 2.50 mm to about 4.0 mm, or about 2.75 mm to about 3.5 mm. In some configurations, the absorbent article has a dry caliper, measured according to the wet and dry CD and MD three-point method, of about 0.07 to 0.30 N / mm 2 and a dry caliper of about 2.0 mm to about 4.5 mm, or about 0.10 to about 0.25 N / mm 2 and a dry caliper of about 2.50 mm to about 4.0 mm, or about 0.10 to about 0.20 N / mm 2 The absorbent article may have a CD dry modulus of about 2.75 mm to about 3.5 mm and a dry caliper of about 10.0 to about 30.0 N as measured by wet and dry CD and MD three-point bending method. * mm 2 , or about 10.0 to about 25.0 N * mm 2 , or about 10 to about 20N * mm 2 , or about 13 to about 20N * mm 2 Particularly suitable absorbent articles may have a CD dry bending stiffness of about 10.0 to about 30.0 N, as measured according to a wet and dry CD and MD three-point method. * mm 2 and a dry caliper of about 2.5 mm to about 4.0 mm, or about 10 to about 25 N * mm 2and a dry caliper of about 2.5 to 4.0 mm, or about 13 to about 30 N * mm 2 and a dry caliper of about 2.75 mm to about 3.5 mm.

[0075] The absorbent article has a resistance of about 1.0 to about 3.5 N. * mm, or about 1.5 to about 3.0 N * mm, or about 1.5 to about 2.8 N * Particularly suitable absorbent articles may have a fifth cycle wetness recovery energy of about 1.0 to 3.5 N * mm 5th cycle wet recovery energy and about 29% to about 40% 5th cycle wet recovery %, or about 1.5 to about 3.0 N * mm 5th cycle wet recovery energy and about 29% to about 40% 5th cycle wet recovery %, or about 1.5 to about 2.75 N * mm and a 5th Cycle Wet Recovery % of about 29% to about 40%.

[0076] Absorbent articles comprising the absorbent core structures disclosed herein may also need to deliver a dry feel to the consumer after the addition of fluid, as measured by the light touch rewet method. Absorbent core structures and absorbent articles that meet the above characteristics are designed to more closely and completely fit the wearer's complex anatomical genital shape, comfortably and gently. Thus, such absorbent articles may also need to be dry to the touch after excretion, so as not to irritate sensitive genital tissue. Thus, the absorbent articles described herein may also maintain a light touch rewet value of less than about 0.15 grams, or less than about 0.12 grams, or from about 0 to about 0.15 grams, or from about 0 to about 0.12 grams.

[0077] The absorbent article may have a combined interfacial and surface free fluid (referred to herein as "Total IFF+SFF"), measured according to the Acquisition and Rewet Test described herein, of from about 20 mg to about 200 mg, alternatively from about 40 mg to about 190 mg.

[0078] The absorbent article may have a Surface Free Fluid (SFF) value of from about 15 mg to about 175 mg, measured according to the Acquisition and Rewet Test described herein.

[0079] The absorbent article may have an interfacial free fluid (IFF) value of from about 12 mg to about 50 mg, measured according to the Acquisition and Rewet Test described herein.

[0080] The absorbent article may have a total absorbency time of from about 12 seconds (s) to about 25 seconds, as measured according to the Acquisition and Rewet Test described herein.

[0081] As shown in Figures 2A-2C, the absorbent article 20 further comprises a chassis 100 comprising an absorbent core structure 10. As shown, the absorbent core structure 10 and / or the inner core layer 200 may comprise a generally hourglass shape. However, any suitable shape may be used. Some examples include an offset hourglass (where one end is wider than the opposite end and a narrow central section between the ends), a bicycle seat shape (where one end and the central portion are narrower than the second end), etc. The side edges 120 and 125 may follow the overall contour of the absorbent core. Thus, if the absorbent core structure has an hourglass shape, the side edges of the absorbent article 120, 125 may be configured and arranged in an hourglass shape as well. However, configurations are also contemplated where the side edges 120 and 125 are generally straight or slightly curved so as not to follow the contour of the absorbent core structure. Further details are provided below. The absorbent article 20 may be symmetrical about a longitudinal centerline 80 or may be asymmetrical about the longitudinal centerline 80. Similarly, the absorbent article 20 may be symmetrical about a lateral centerline 90 or may be asymmetrical about the lateral centerline 90.

[0082] Top sheet The topsheet 110 may be formed from any suitable nonwoven web or formed film material (see FIG. 6). Referring again to the figure, the topsheet 110 is positioned adjacent to the wearer-facing surface of the absorbent layer 20 and may be joined to that surface and to the backsheet 130 by any suitable attachment or bonding method. The topsheet 110 and backsheet 130 may be directly bonded to each other in the outer peripheral area around the periphery of the absorbent core structure, or may be indirectly bonded by being directly bonded to the wearer-facing and outer-facing surfaces of the absorbent article, respectively, or to additional optional layers included in the absorbent article.

[0083] The absorbent article 20 may have any known or otherwise effective topsheet 110 that is conformable, soft feeling, non-irritating, etc. against the wearer's skin. Suitable topsheet materials include liquid permeable materials that are comfortable when in contact with the wearer's skin and allow expelled menstrual fluid to rapidly permeate therethrough. Some suitable examples of topsheet materials include films, nonwovens, laminate structures including 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 topsheet 110 include fibrous materials made from natural fibers, modified natural fibers, synthetic fibers, or combinations thereof. Some suitable examples are described in U.S. Patent Nos. 4,950,264, 4,988,344, 4,988,345, 3,978,185, 7,785,690, 7,838,099, 5,792,404, and 5,665,452.

[0085] The topsheet 110 may be compliant, soft feeling, and non-irritating to the wearer's skin. Further, the topsheet 110 may be liquid permeable such that liquids (e.g., urine, menses) may readily penetrate through its thickness. Some suitable examples of topsheet materials include films, nonwovens, laminated structures including film / nonwoven layers, film / film layers, and nonwoven / nonwoven layers. Other exemplary topsheet materials and designs are disclosed in U.S. Patent Application Publication Nos. 2016 / 0129661, 2016 / 0167334, and 2016 / 0278986.

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

[0087] In some examples, the topsheet 110 may be formed from a nonwoven web material that includes monocomponent continuous fibers, or alternatively, a spunbond web that includes bicomponent or multicomponent fibers, or a blend of monocomponent fibers spun from different polymer resins, or any combination thereof. The topsheet may also be a molded nonwoven topsheet such as those disclosed in U.S. Patent Application Publication No. 2019 / 0380887.

[0088] To ensure that fluids contacting the top (wearer-facing) surface of the topsheet can be suitably and quickly transferred in the z-direction to the bottom (outward-facing) surface of the topsheet where they can be drawn into the absorbent layer, it can be important to ensure that the nonwoven web material forming the topsheet has an appropriate weight / volume density, which reflects the suitable presence of interstitial passages (also called "pores") in and between the constituent fibers through which fluids can move within the nonwoven material. In some circumstances, nonwoven materials with fibers that are too tightly consolidated will have insufficient number and / or volume and / or size of pores, such that the nonwoven will hinder rather than promote rapid downward z-direction fluid movement. On the other hand, nonwovens with fibers that are too large and / or not consolidated to provide a certain level of opacity (for the purpose of hiding fluids absorbed in the layers below) and a fair appearance can be perceived negatively by the user.

[0089] The caliper of the topsheet material may be controlled to balance the competing needs of opacity and loft (requiring a higher caliper) and limiting the z-direction distance that exuded fluid must travel through the topsheet from the wearer-facing surface to the outwardly facing surface to reach the underlying absorbent core component. Thus, it may be desirable for the manufacture of topsheet materials to be controlled to produce topsheet materials having a caliper of from about 0.20 mm to about 1.0 mm, or from about 0.25 mm to about 0.80 mm, or from about 0.30 mm to about 0.60 mm.

[0090] The absorbent article may include an anti-stick agent applied to at least a portion of the wearer-facing surface of the topsheet. The anti-stick agent may include a polypropylene glycol (PPG) material and a carrier. It is believed that the applied anti-stick agent may perform functions including reducing adhesion of menstrual fluid to the user's / wearer's skin and facilitating the transfer of menstrual fluid from the wearer-facing surface of the topsheet through it to the underlying fluid management layer and / or absorbent structure layer. Performing these functions may enhance the perception of cleanliness of the user's / wearer's skin and the topsheet, especially after repeated discharge of menstrual fluid.

[0091] Anti-stick agents contemplated herein may include PPG material at a level of about 0.1% to about 100% by weight of the anti-stick agent. In some embodiments, the anti-stick agent may include less than about 10% by weight of the anti-stick agent, preferably about 0.5% to about 8% by weight, more preferably about 1% to about 5% by weight of the anti-stick agent. In some configurations, the anti-stick agent may include at least about 50% by weight of the anti-stick agent, preferably about 75% to about 100% by weight, more preferably about 90% to about 100% by weight of the anti-stick agent. Anti-stick agents contemplated herein may include a carrier at a total carrier concentration ranging from about 60% to about 99.9% by weight of the anti-stick agent, preferably about 70% to about 99.5% by weight, more preferably about 80% to about 99% by weight.

[0092] Examples of suitable anti-adherents and / or surfactants useful therein are disclosed in US Patent Application Publication No. 2009 / 0221978 (the compositions are referred to as "lotions") and US Patent No. 8,178,748, and US Patent Application No. 63 / 256,164. A particularly preferred example of a suitable polyethylene glycol material is PPG-15 stearyl ether, such as the product sold as CETIOL E by BASF Corporation, Florham Park, New Jersey, USA, and / or BASF SE, Ludwigshafen, Germany. A particularly preferred example of a suitable carrier is caprylic / capric triglyceride, such as MYRITOL 318, a product of BASF Corporation, Florham Park, New Jersey, USA, and / or BASF SE, Ludwigshafen, Germany.

[0093] Secondary Topsheet (STS) An STS layer may, in some circumstances, be included between the topsheet and the absorbent core structure to enable the absorbent core structure to readily receive a sudden gush of fluid and then wick it up along the x and y directions and distribute it across the underlying absorbent core structure.

[0094] If included, the STS may be a nonwoven fibrous structure that may include cellulosic fibers, non-cellulosic fibers (e.g., fibers spun from polymeric resins), or blends thereof. To accommodate the folding and lateral gathering of the absorbent article 20 and absorbent core structure 10, as described herein, the STS may be formed from a material that is relatively flexible (i.e., has a relatively low bending stiffness).

[0095] Some specific examples of suitable STS compositions and structures, and combinations thereof with suitable topsheet compositions and structures, are further described in U.S. Patent Application Nos. 16 / 831,862, 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 Application Nos. 63 / 086,610 and 63 / 086,701. Additional suitable examples are described in U.S. Patent No. 9,504,613, WO 2012 / 040315, and U.S. Patent Application Publication No. 2019 / 0021917.

[0096] In some configurations, the absorbent article may not include a secondary topsheet.

[0097] Back sheet The backsheet 130 may be positioned below or adjacent to the outwardly facing surface of the absorbent layer 10 and may be joined to that surface by any suitable attachment method. For example, the backsheet 130 may be secured to the absorbent core structure 10 by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of discrete lines, spirals or dots of adhesive. Alternatively, the attachment method may include thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other suitable attachment mechanism, or combinations thereof. In other examples, it is contemplated that the absorbent core structure 10 is not directly joined to the backsheet 130.

[0098] The backsheet 130 may be impermeable or substantially impermeable to aqueous liquids (e.g., urine, menstrual fluid) and may be fabricated from a thin plastic film, although other flexible liquid impermeable materials may be used. As used herein, the term "flexible" refers to a material that is conformable and readily conforms to the general shape and contours of the human body. The backsheet 130 may prevent, or at least substantially prevent, fluids absorbed and contained within the absorbent core structure 10 from escaping and reaching articles of clothing of the wearer that may come into contact with the absorbent article 20, such as undergarments and other garments. However, while in some instances the backsheet 130 allows vapors to escape from the absorbent core structure 10 (i.e., the backsheet is made to be breathable), in other instances the backsheet 130 may be made to not allow vapors to escape (i.e., made to be non-breathable). Thus, the backsheet 130 may comprise a polymeric film, such as a thermoplastic film of polyethylene or polypropylene. A suitable material for the backsheet 130 is a thermoplastic film having a thickness of, for example, from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mil). Any suitable backsheet known in the art may be utilized with the present invention.

[0099] Some suitable examples of materials suitable for forming the backsheet are described in U.S. Patent Nos. 5,885,265, 4,342,314, and 4,463,045.Single-layer breathable backsheets suitable for use herein are described, for example, in British Patent Nos. A2184389, A2184390, and A2184391, U.S. Patent Nos. 4,591,523, 3,989,867, and 3,156,242, International Publication No. WO 97 / 24097, and U.S. Patent Nos. 6,623,464, 6,664,439, and 6,436,508.

[0100] The backsheet 130 may have two layers, a first layer comprising a vapor-permeable apertured formed 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 dual or multi-layer breathable backsheets for use herein include those described in U.S. Patent Nos. 3,881,489, 4,341,216, 4,713,068, 4,818,600, European Patent Application Publication Nos. 203821, 710471, 710472, and 0793952.

[0101] Other features In some configurations, the absorbent article 20 may include an adhesive deposit to provide a mechanism for a user to adhere the absorbent article to the inside crotch region of an undergarment. When the absorbent article 20 is packaged for shipping, handling and storage prior to use, the adhesive deposit may be covered by one or more sheets of release film or paper (not shown) which covers / shields the adhesive deposit from contacting other surfaces until the user removes the release film or paper and places the absorbent article in an undergarment for wear / use.

[0102] In some configurations, the absorbent article 20 may include opposing wing portions 140, 150 on each side that extend laterally beyond the longitudinal edges of the absorbent portion of the absorbent article by a width dimension that is relatively larger than the width dimensions of the front and rear portions of the absorbent article. Wings are currently commonly provided on feminine hygiene absorbent articles. As provided, they typically have an adhesive deposit applied to their outwardly facing surfaces (the surfaces facing outward prior to placement of the absorbent article in the user's undergarment and application of the wings). The wing portions may also include an adhesive deposit as described above, which allows the user to wrap the wing portions around the inner edges of the undergarment through the leg openings of the undergarment and adhere the wing portions to the outwardly facing surface / underside of the undergarment in the crotch region, providing additional retention support for the absorbent article and helping to protect the undergarment adjacent the leg edges of the undergarment from soiling.

[0103] Test Method Target demographic For any of the following methods in which not all of the constituent layers of an article are tested, the layers of interest may be separated from the layers not being tested, if necessary, using cryospray.

[0104] Breaking Strain Method The force versus displacement behavior of the samples is measured on a universal constant rate of extension test frame equipped with a load cell that measures forces within 1% to 99% of the cell's limits (a suitable instrument is MTS Alliance using TestSuite Software, available from MTS Systems Corp., Eden Prairie, Minn., or equivalent). Samples are subjected to a constant rate of tensile extension (mm / sec) until break, and the percent strain at break is measured. All tests are performed in a conditioned room at 23° C.±3° C. and 50%±2% relative humidity, and test samples are conditioned in this environment for at least 2 hours prior to testing.

[0105] The fixtures used to grip the test specimens are light-weight (<80 grams) vice action clamps with gripping faces of half-cylindrical steel to rubber-coated steel at least 40 mm wide. The fixtures are mounted on a universal testing frame and are aligned horizontally and vertically with each other.

[0106] Test samples are prepared as follows: If necessary, test material is obtained by cutting from the absorbent article. When cutting the test material, the process is taken to ensure that the material layer is not contaminated or deformed in any way. The test sample is cut from an area of ​​the test material that does not contain folds or wrinkles. The test sample is 100 mm long (parallel to the horizontal or intended horizontal axis of the article) and 25.4 mm wide (parallel to the vertical or intended vertical axis of the article). Similarly, five replicate test samples are prepared.

[0107] The universal test frame is prepared as follows: The initial inter-grip separation distance is set to the nominal gauge length of 80 mm, then the crosshead is zeroed. To ensure that there is no pretension in the test specimen at the start of the test, the test frame is programmed to move the grips closer together by an intentional slack of 1 mm. (During this movement, the specimen slackens between the grips.) The grips then move apart at a slack rate of 1 mm / s until a slack preload of 0.05 N is exceeded. (At this point, the crosshead position signal is used to calculate the sample slack, the adjusted gauge length, and define the strain as zero, i.e., 0.0). The grips then move apart at a rate of 1 mm / s until the sample breaks or the extension limit of the instrument is exceeded.

[0108] The test is performed by inserting the test sample into the grips so that the long axis of the sample is parallel to and centered around the crosshead motion. The test is started and force ("load") and displacement data are collected continuously at a data collection rate of 100 Hz.

[0109] A graph of load (N) versus displacement (mm) is generated. The peak load is determined from the curve and then the break sensitivity is determined as follows: The crosshead position at which the load signal decreases by 75% after the peak load is reached is determined and recorded to the nearest 0.01 mm as the final specimen length (Lf); The initial specimen length is defined by the crosshead position when the slack preload of 0.05 N is exceeded and this value is recorded to the nearest 0.01 mm as the initial specimen length (Li); The percent break strain is calculated as follows and recorded to the nearest 1 percent: Breaking strain % = ((Lf-Li) / Li) * 100

[0110] This procedure is repeated in the same manner for all five replicate test specimens. The arithmetic mean of the % Strain at Break for the five replicate test specimens is calculated and reported as % Strain at Break to the nearest percent.

[0111] Wet and dry CD and MD 3-point bending method The flexural properties of absorbent article test samples are measured on a universal constant rate of extension test frame equipped with a load cell that measures forces within 1% to 99% of the cell's limits (a suitable instrument is MTS Alliance using TestSuite Software, or equivalent, available from MTS Systems Corp., Eden Prairie, MN). Tests are performed on dry as well as wet test specimens. The intent of this method is to mimic the deformations produced in the xy plane by the wearer of an absorbent article during normal use. All tests are performed in a controlled room at 23°C ± 3°C and 50% ± 2% relative humidity.

[0112] The bottom stationary fixture consists of two cylindrical bars made of polished stainless steel, 3.175 mm in diameter and 110 mm in length, mounted at each end by frictionless rolling bearings. The two bars are mounted horizontally and aligned back-to-back and parallel to each other, with the top radii of the bars aligned vertically, and are free to rotate around the diameter of the cylinder by frictionless bearings. The fixture further allows the two bars to be moved horizontally away from each other on a track, so that a gap can 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, 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 and aligned back-to-back with the bars of the lower fixture, and are centered between the bars in the case of the lower fixture. Both fixtures include an integral adapter suitable for mating with a respective location on the universal test frame and fixing them in place so that the bars are perpendicular to the movement of the cross beam of the test frame.

[0113] Set the gap ("span") between each bar of the lower fixture to 25mm ± 0.5mm (from center of bar to center of bar) with the center of the upper bar aligned with the midpoint between each of the lower bars. Set the gauge (from the bottom of the upper bar to the top of the lower bar) to 1.0cm.

[0114] The thickness ("caliper") of the test specimen is measured with a manual micrometer equipped with a foot press capable of applying a constant pressure of 0.10 psi ± 0.01 psi. The manual micrometer is a deadweight instrument with an accurate reading to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, available from VWR International, or equivalent. The foot press is a flat-faced circular movable surface having a diameter of 25.4 mm or less. The test specimen is supported by a horizontal flat reference platform that is larger than and parallel to the surface of the foot press. The micrometer is zeroed against the horizontal flat reference platform. The test specimen is placed on the platform and centered under the foot press. The foot press is lowered by hand at a downward speed of 3 + 1 mm / s until the full weight pressure is applied to the specimen. After 5 seconds, the thickness is recorded as the caliper to the nearest 0.01 mm.

[0115] The test fluid used to administer the wet test specimens is prepared by adding 100.0 grams of sodium chloride (reagent grade, any convenient source) to 900 grams of deionized water in a 1 liter Erlenmeyer flask. Stir until the sodium chloride is completely dissolved.

[0116] Condition absorbent article samples at 23°C ± 3°C and 50% ± 2% relative humidity for 2 hours prior to testing. Dry test specimens are taken from areas of the sample that are free of seams and remaining folds or wrinkles, ideally from the center of the absorbent article (the intersection of the longitudinal and transverse centerlines). Dry specimens are prepared for MD (machine direction) bending by cutting 50.8 mm wide along the CD (transverse direction, i.e., parallel to the transverse axis of the sample) and 50.8 mm long along the MD (parallel to the longitudinal axis of the sample), maintaining their orientation after they are cut, and marking the body-facing surface (or the surface intended to face the body on the finished product). Dry specimens are prepared for MD (machine direction) bending by cutting them to a width of 50.8 mm along the MD (transverse direction, i.e., parallel to the transverse axis of the sample) and a length of 50.8 mm along the CD (parallel to the longitudinal axis of the sample), maintaining their orientation after they are cut, and marking the body-facing surface (or the surface intended to face the body of the finished product). The thickness of the test specimen is measured as described herein and recorded as the dry specimen caliper to the nearest 0.01 mm. The mass of the test specimen is then measured and recorded as the dry mass to the nearest 0.001 grams. The mass (g) is then multiplied by the area (0.002581 m2). 2 ) to obtain a dry sample basis weight of 0.01 g / m 2 Record the sample weight in units of g / m 2 ) by the thickness of the sample (mm) and then divide the quotient by 1000 to calculate the bulk density of the sample, which is 0.01 g / cm for the dry sample density. 3 Record in units. Similarly, prepare five replicate dry test samples.

[0117] The wet test specimen is first prepared in exactly the same manner as the dry test specimen, followed by the addition of the test fluid immediately prior to testing as follows: First, measure the thickness and mass of the dry specimen as described herein and record as the initial thickness to the nearest 0.01 mm and as the initial mass to the nearest 0.001 g. The dry specimen is then completely submerged in the test fluid for 60 seconds. After the 60 seconds have elapsed, the specimen is removed from the test fluid and oriented vertically for 30 seconds to allow excess fluid to drip off. Now, measure the thickness and mass of the wet specimen as described herein and record as the wet specimen caliper to the nearest 0.01 mm and as the wet specimen mass to the nearest 0.001 g. The mass of the test specimen is then measured and recorded as the dry mass to the nearest 0.001 grams. If desired, calculate the mass of the test fluid in the test specimen by subtracting the initial mass (g) from the wet specimen mass (g) and record as the test specimen fluid mass to the nearest 0.001 g. The wet test specimen must be tested within 10 minutes of removal from the test fluid. Similarly, five replicate wet test specimens are prepared.

[0118] The universal testing frame for flexure bending tests is programmed such that the upper fixture moves downward relative to the lower fixture at a rate of 1.0 mm / s until the upper bar touches the top surface of the sample with a minimum force of 0.002 N, then the crosshead moves to continue for an additional 12 mm. The crosshead is then immediately returned to the original gauge at a rate of 1.0 mm / s. Force (N) and displacement (mm) data are collected continuously at 100 Hz throughout the test.

[0119] The dry test specimen is loaded across the two lower bars with its sides parallel to each bar and centered under the upper bar. For MD bending, the MD direction of the test specimen is perpendicular to the length of the three bars. The test is started and force and displacement data are collected continuously.

[0120] A graph of force (N) versus displacement (mm) is made. From the graph, the maximum peak force is determined and recorded to the nearest 0.01 N as the dry MD peak load. The maximum slope of the curve between the initial force and the maximum force (during the loading portion of the curve) is then calculated and recorded to the nearest 0.1. The modulus is calculated as follows and is expressed as the dry MD modulus of elasticity in units of 0.001 N / mm 2 Record in units. CD or MD dry or wet flexural modulus (N / mm 2 )=(slope x (span 3 ) / (4 x sample width x (sample caliper 3 ))

[0121] The bending stiffness is calculated as follows, with the dry MD bending stiffness being 0.1 Nmm 2 Record in units. CD or MD dry or wet bending stiffness (Nmm 2 ) = Modulus of elasticity x moment of inertia. Where, moment of inertia (mm 4 )=(sample width * Caliper 3 )) / 12

[0122] The procedure is repeated for all five replicates of the dry test specimen in the same manner. The arithmetic mean of the five replicate dry test specimens is calculated for each parameter, the dry specimen "caliper" to the nearest 0.01 mm, the 0.01 g / m 2 Unit of dry sample basis weight 2 , 0.001g / cm 3 Dry sample density in units of 0.01N Dry CD or MD peak load in units of 0.001N / mm 2 Units of dry CD or MD flexural modulus, and Nmm 2 Report as unit dry CD or MD bending stiffness.

[0123] Now, the entire procedure is repeated for all five replicates of the wet test specimen and the results are reported as wet CD or MD peak load to the nearest 0.01 N, wet CD or MD peak load to the nearest 0.001 N / mm 2 Wet CD or MD flexural modulus in units, and Nmm 2 Report as unit wet CD or MD bending stiffness.

[0124] Wet and dry CD ultra-sensitive three-point bending method The CD (transverse direction) bending properties of the test samples are measured using an ultra-sensitive 3-point bending test on a universal constant rate of extension test frame (a suitable instrument is MTS Alliance using TestSuite Software available from MTS Systems Corp., Eden Prairie, Minn., or equivalent) equipped with a load cell appropriate for the force to be measured. Testing is performed on dry test specimens as well as wet specimens. The intent of this method is to mimic the deformations produced in the xy plane by the wearer of an absorbent article during normal use. All testing is performed in a controlled room at 23° C.±3° C. and 50%±2% relative humidity.

[0125] The ultra-sensitive three-point bend method is designed to maximize the force signal to noise ratio when testing materials at very low bending forces. The force signal is maximized by using a sensitive load cell (e.g., 5N), using a small span (load is proportional to the cube of the span), and using a wide sample width (total load measured is directly proportional to width). The fixture is designed so that the bend measurements are made under tension, allowing the fixture mass to be kept to a minimum. Noise in the force signal is minimized by holding the load cell stationary to reduce mechanical vibration and inertia effects, and by keeping the mass of the fixture attached to the load cell as small as possible.

[0126] With reference to Figures 7A-7C, the load cell 1001 is mounted on a fixed crosshead of a universal test frame. The ultra-sensitive 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, rounded edges, and a length capable of accommodating a bending width of 100 mm. Each of the blades has cavities 1004a and 1004b (outer blades) and 1005 (center blade) cut out to create a 5 mm height h of blade material along their horizontal edges. The two outer blades 1003a and 1003b are mounted horizontally on the movable crosshead of the universal test frame and are 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 (from inner edge to inner edge). The central blade 1002 is attached to a load cell on the fixed crosshead of the universal test frame. When in position, the central blade 1002 is parallel to the two outer blades 1003a and 1003b and is centered at the midpoint between the outer blades 1003a and 1003b. The blade fixture includes an integral adapter suitable for fitting into each position on the universal test frame and fixing in place so that the horizontal edge of the blade is perpendicular to the movement of the cross beam of the universal test frame.

[0127] The test fluid used to administer to the wetted specimens is prepared by adding 100.0 grams of sodium chloride (reagent grade, any convenient source) to 900 grams of deionized water in a 1 liter Erlenmeyer flask. Stir until the sodium chloride is completely dissolved.

[0128] Condition the samples at 23°C ± 3°C and 50% ± 2% relative humidity for 2 hours prior to testing. Dry test specimens are taken from areas of the sample that are free of seams and remaining folds or wrinkles. Dry specimens are prepared for CD bending (i.e. bending perpendicular to the sample's transverse axis) by cutting them to 50.0 mm width along the CD (transverse direction, i.e. parallel to the sample's transverse axis) and 100.0 mm length along the MD (machine direction, i.e. parallel to the sample's longitudinal axis), maintaining their orientation after they are cut, and marking the body-facing surface (or the surface intended to face the body of the finished product). Similarly, prepare five replicate dry test specimens.

[0129] Wet test specimens are first prepared in exactly the same manner as for dry test specimens, followed by the addition of test fluid immediately prior to testing as follows: The dry specimen is completely submerged in the test fluid for 60 seconds. After the 60 seconds have elapsed, the specimen is removed from the test fluid and oriented vertically for 30 seconds to allow excess fluid to drip off. After the wet test specimen is removed from the test fluid, it must be tested within 10 minutes. Similarly, five replicate wet test specimens are prepared.

[0130] The universal test frame is programmed such that the movable crosshead is set to move in the opposite direction to the fixed crosshead at a rate of 1.0 mm / sec. The crosshead movement begins with the specimen 1006 flat and undeflected on the outer blades 1003a and 1003b, continues with the inner horizontal edge of the cavity 1005 in the central blade 1002 in contact with the top surface of the specimen 1006, and continues with an additional 4 mm of crosshead movement. The crosshead stops at 4 mm and then immediately returns to zero at a rate of 1.0 mm / s. Force (N) and displacement (mm) are collected throughout at 50 Hz.

[0131] Prior to loading the test sample 1006, the outer blades 1003a and 1003b are moved towards the central blade 1002 until there is a clearance C of about 3 mm between the inner horizontal edges of the cavities 1004a and 1004b in the outer blades 1003a and 1003b and the inner horizontal edge of the cavity 1005 in the central blade 1002, and then pass the central blade 1002 (see FIG. 7C). The sample 1006 is positioned within the clearance so that it straddles the inner horizontal edges of the cavities 1004a and 1004b in the outer blades 1003a and 1003b, oriented so that the MD (short side) of the sample is perpendicular to the horizontal edges of the blades and the body-facing surface of the sample is facing upwards. Center the sample 1006 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 in the central blade 1002 contacts the top surface of the specimen 1006. The test is started and force and displacement data are collected continuously.

[0132] Plot force (N) against displacement (mm). Record maximum peak force to the nearest 0.001 N. Calculate the area under the curve from the start of loading to maximum peak force and record as bending energy to the nearest 0.001 N-mm. Calculate recovery energy as the area under the curve where the force is unloaded from maximum peak to 0.0 N and record as recovery energy to the nearest 0.001 N-mm. Similarly, repeat the entire test procedure for a total of five dry test specimens and five wet test specimens.

[0133] For each test specimen type (dry and wet), calculate the arithmetic mean of maximum peak force among like specimens to the nearest 0.001 N and report it as Dry Peak Load and Wet Peak Load, respectively. For each test specimen type (dry and wet), calculate the arithmetic mean of bending energy among like specimens to the nearest 0.001 N-mm and report it as Dry Bend Energy and Wet Bend Energy, respectively. For each test specimen type (dry and wet), calculate the arithmetic mean of recovery energy among like specimens to the nearest 0.001 N-mm and report it as Dry Recovery Energy and Wet Recovery Energy, respectively.

[0134] Wet and dry bunch compression methods The Bundled Compression test method uses a universal constant rate of extension test frame (a suitable instrument is MTS Alliance using TestSuite software available from MTS Systems Corp., Eden Prairie, MN, or equivalent) equipped with a load cell where the force measured is within 1% to 99% of the cell's limits to measure the force versus displacement behavior of intentionally "bundled" absorbent article test samples over five cycles of load application ("compression") and load removal ("recovery"). The test is performed on dry test specimens as well as wet specimens to which a specific amount of test fluid has been administered. The intent of the method is to mimic the deformations that occur in the z-plane of the crotch region of an absorbent article or its components when worn by a wearer during a sit-to-stand motion. All tests are performed in a room controlled at 23°C ± 3°C and 50% ± 2% relative humidity.

[0135] The test apparatus is shown in Figures 8-9B. The bottom static fixture 3000 consists of two matching sample clamps 3001, each 100 mm wide, mounted on their own moveable platforms 3002a, 3002b. The clamps have 110 mm long "knife edges" 3009 that grip a 1 mm thick hard rubber surface 3008. When closed, the clamps are flush with the inside of their respective platforms. The clamps are aligned to hold the unbunched specimen horizontally and perpendicular to the tensile axis of the tensile tester. The platforms are mounted on rails 3003, which allow the platforms to be moved horizontally from side to side and locked into position. The rails have adapters 3004 that fit the tensile tester mounts, allowing the platforms to be fixed horizontally and perpendicular to the tensile axis of the tensile tester. The top fixture 2000 is a cylindrical plunger 2001 with an overall length of 70 mm and a diameter of 25.0 mm. The contact surface 2002 is flat and has no curvature. The plunger 2001 has an adapter 2003 that fits onto the mount of a load cell, allowing the plunger to be fixed perpendicular to the tensile axis of the tensile tester.

[0136] Condition the test samples at 23°C ± 3°C and 50% ± 2% relative humidity for at least 2 hours prior to testing. Prepare the test specimen as follows: When testing a pristine absorbent article, remove the release paper from any panty fastening adhesive on the garment-facing side of the article, if present. Lightly coat the adhesive with talc powder to reduce any sticky feeling. Cut away the cuffs, if present, with scissors, being careful not to disturb the topsheet or any other underlying layers of the article. Place the article on a bench with the body-facing surface up. Mark the intersection of the longitudinal and lateral centerlines on the article. Using a rectangular cutting die or equivalent cutting means, cut the sample 100 mm longitudinally and 80 mm transversely, centered on the intersection of the centerlines. If testing a layer or layered component of an absorbent article, place the layer or synergistic component on the bench and orient it as it will be incorporated into the finished product (i.e., identify the surface facing the body and the transverse and longitudinal axes). Using a rectangular cutting die or equivalent cutting means, cut the sample 100 mm long and 80 mm wide, centered at the intersection of the centerlines. Measure the mass of the sample to the nearest 0.001 g. Multiply the mass (g) by the area (0.008 m2). 2 ) to calculate the basis weight of the sample, and use 1 g / m 2 Record in units.

[0137] Test specimens can be analyzed both wet and dry. Dry specimens require no further preparation. Prepare the test fluid used to dose the wet test specimens by adding 100.0 grams of sodium chloride (reagent grade, any convenient source) to 900 grams of deionized water in a 1 liter Erlenmeyer flask. Stir until the sodium chloride is completely dissolved. Dose a total of 7 ml of test solution to the wet specimens as detailed below.

[0138] The liquid dose is applied using a graduated Eppendorf pipette while spreading the fluid across the body-facing surface of the specimen within approximately 3 seconds. Wet specimens are tested 10.0 minutes ± 0.1 minutes after application of the dose.

[0139] The tensile tester is programmed to zero the load cell and then lower the upper fixture at 2.00 mm / sec until the plunger contact surface touches the specimen and the load cell reads 0.02 N. The crosshead is zeroed. The system is programmed to lower the crosshead 15.00 mm at a rate of 2.00 mm / sec and immediately raise the crosshead 15.00 mm at a rate of 2.00 mm / sec. This cycle is repeated for a total of 5 cycles with no delay between cycles. Data during all compression / decompression cycles is collected at 50 Hz.

[0140] The left platform 3002a is positioned 2.5 mm from the side of the upper plunger (distance 3005). The position of the left platform is fixed. This platform 3002a remains stationary throughout the experiment. The right platform 3002b is aligned 50.0 mm from the stationary clamp (distance 3006). The upper probe 2001 is raised so that it does not interfere with the loading of the specimen. Both clamps 3001 are opened. Referring to FIG. 9A, the dry sample is placed in the clamps with its longitudinal edge (i.e., the edge with a length of 100 mm). The dry sample is laterally centered and both edges are secured in the clamps. Referring to FIG. 9B, the right platform 3002b is moved a distance of 20 mm toward the stationary platform 3002a so that a separation of 30.0 mm between the left and right clamps is achieved. When the movable platform is positioned, the dry sample is allowed to bend upwards. Now, probe 2001 is manually lowered until its lower surface is located approximately 1 cm from the top surface of the bent sample.

[0141] The test is started and the force (N) and displacement (mm) data are collected continuously for all five cycles. A graph of force (N) versus displacement (mm) is created for every cycle individually. A representative curve is shown in FIG. 10A. From the curve, the dry maximum compression force of each cycle is determined to the nearest 0.01 N, then multiplied by 101.97 and recorded to the nearest 1 gram force. The dry recovery % between the first and second cycles is calculated as (TD-E2) / (TD-E1)×100, where TD is the total deflection and E2 is the extension in the second compression curve over 0.02 N, and recorded to the nearest 0.01%. In the same manner, the dry recovery % between the first and other cycles is calculated as (TD-E1) / (TD-E1)×100, and recorded to the nearest 0.01%. Referring to FIG. 10B, the dry compression energy for cycle 1 is calculated as the area under the compression curve (i.e., Area A+B) and reported to the nearest 0.1 N-mm. The drying energy loss from cycle 1 is calculated as the area between the compression curve and the decompression curve (i.e., Area A) and reported to the nearest 0.1 N-mm. The dry recovery energy for cycle 1 is calculated as the area under the decompression curve (i.e., Area B) and reported to the nearest 0.1 N-mm. Similarly, the dry compression energy (N-mm), drying energy loss (N-mm), and dry recovery energy (N-mm) are calculated and reported to the nearest 0.1 N-mm for each of the other cycles. Similarly, a total of five replicate dry test specimens are analyzed and the arithmetic average across the five dried replicates is reported for each of the aforementioned parameters, including basis weight.

[0142] Here, the entire procedure is repeated for a total of five replicate wet test specimens, and the results for each of the five cycles are reported as the arithmetic mean of the five wet replicates for wet maximum compressive force in grams force for each cycle, wet compression energy in 0.1 N-mm for each cycle, wet energy loss in 0.1 N-mm for each cycle, wet recovery energy in 0.1 N-mm for each cycle, and % wet recovery for each cycle. Of particular importance are the 5th cycle wet recovery energy and 5th cycle wet recovery percentage properties from this test method.

[0143] CD cyclic tensile extension up to 3% strain The cyclic tensile and recovery response of absorbent article samples is measured for 10 cycles of load application ("extension") and load removal ("recovery") using a universal constant rate extension test frame. The test sample is cycled 10 times to an engineering strain of 3% and then returned to zero engineering strain. For each cycle, the stiffness, peak load, normalized peak energy, normalized recovery energy, strain at the start of the cycle, and strain at the end of the cycle (i.e., "permanent set") are calculated and reported. The intent of this method is to understand the ability of samples to be stretched in the xy plane as a result of body forces and then recover to their original state. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and test specimens are conditioned in this environment for at least 2 hours prior to testing.

[0144] A suitable universal constant rate of extension test frame is an MTS Alliance, or equivalent, interfaced to a computer running TestSuite control software (available from MTS Systems Corp, Eden Prairie, Minn.). The universal test frame is equipped with a load cell whose measured force is within 1% to 99% of the cell's limits. The fixtures used to grip the test specimen are light-weight (<80 grams), vice-action clamps with knife or serrated edge gripping faces at least 40 mm wide. The fixtures are mounted on the universal test frame and are aligned horizontally and vertically with each other.

[0145] Test specimens are prepared as follows: If necessary, test material is obtained by cutting from an absorbent article. When cutting the test material, care should be taken not to contaminate or deform any of the material layers in the process. The test sample is cut from an area of ​​the test material that does not retain any folds or wrinkles. The test sample is as long as the lateral length of the article (parallel to the lateral axis of the article, or the intended lateral axis of the article). When cutting samples from absorbent articles of different sizes and widths, the total length of the sample (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 or intended longitudinal axis of the article). Specimen width (w) = 25.4 mm. Total specimen length (L total ) is measured and recorded to the nearest 0.1 mm. Five replicate test specimens are prepared in the same manner.

[0146] Measure the thickness (t) of the test specimen using a manual micrometer equipped with a foot press capable of applying a constant pressure of 0.1 psi ± 0.01 psi. The manual micrometer is a deadweight instrument with an accurate reading to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, available from VWR International, or equivalent. The foot press is a flat-faced circular movable surface having a diameter of 25.4 mm or less. The test specimen is supported by a horizontal flat reference platform that is larger than and parallel to the surface of the foot press. The micrometer is zeroed against the horizontal flat reference platform. The test specimen is placed on the platform and centered under the foot press. The foot press is lowered by hand at a descending rate of 3 + 1 mm / s until the full weight pressure is applied to the specimen. After 5 seconds, record the thickness to the nearest 0.01 mm as the specimen thickness (t).

[0147] Prepare the universal test frame as follows: Set the initial grip separation to the nominal gauge length (L) less than the overall length of the specimen. nominal ) so that the sample can be securely gripped at both ends (i.e., L nominal <L total ). The crosshead is then zeroed. To ensure that there is no pretension in the test specimen at the start of the test, the test frame is programmed to move the grips closer together by an intentional slack of 1 mm. (During this movement, the specimen slackens between the tensile grips.) The grips then move apart at a slack rate of 1 mm / s until the slack preload of 0.05 N is exceeded. At this point: 1) The crosshead position signal (mm) is timed to the specimen slack (L slack2) Initial sample gauge length (L 0 ) is the nominal gauge length + slack L 0 =L nominal +L slack Calculate 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. Engineering strain is calculated by dividing the change in length (ΔL) by the initial length (L 0 ) Engineering strain = ΔL / L 0 For one test cycle, the grips are moved apart at an initial rate of 1 mm / s until they exceed the engineering strain endpoint of 0.03 mm / mm, and immediately thereafter, the grips are moved towards each other at an initial rate of 1 mm / s until the crosshead signal is below the crosshead return position of 0 mm. The test cycle is repeated until a total of 10 cycles are completed.

[0148] The test is performed by inserting the test sample into the grips so that the long axis of the sample is parallel to and centered around the crosshead motion. The test is started and time, force and displacement data are collected continuously at a data collection rate of 100 Hz.

[0149] A graph of load (N) versus displacement is made separately for all 10 cycles. For each cycle, do the following: Record the peak load to the nearest 0.01 N. Record the peak energy (E) as the area under the load versus displacement curve from the start of the cycle to the end of strain of 0.03 mm / mm (during the loading portion of the cycle). peak ) and calculate 0.01N * Record in mm. Calculate the return energy as the area under the load vs. displacement curve from the strain end of 0.03 mm / mm to the crosshead return of 0 mm (during the unloading portion of the cycle) and set it to 0.01 N. * Record the recovery energy in mm. Normalized peak energy (NE) is calculated as the peak energy divided by the initial length. peak ) and calculate (NE peak =E peak / L0 ), recorded to the nearest 0.01 mN. Normalized return energy (NE) is calculated as the return energy divided by the initial length. return ) and calculate (NE return =E return / L 0 ), recorded to the nearest 0.01 mN. peak and N.E. return The unit of force is millinewton (mN).

[0150] Now create a graph of Engineering Stress (σ) versus Engineering Strain for all 10 cycles and for each cycle: N / mm 2 Engineering stress, in units of σ, is the load divided by the cross-sectional area of ​​the specimen, which is the width (w) multiplied by the thickness (t) of the specimen (σ = load / (w * t). The modulus of elasticity, or the slope of the stress vs. strain curve, is determined for the line between the points occurring at the minimum and maximum forces (during the loading portion of the cycle) and recorded as the modulus of elasticity to the nearest 0.01 N / mm. The stiffness is calculated by multiplying the modulus of elasticity by the thickness of the sample and recorded as the tensile stiffness to the nearest 0.01 N / mm. The strain of the test specimen at the beginning of the cycle is defined by the strain when the slack preload of 0.05 N is exceeded for that cycle (during the loading portion of the cycle) and recorded as the cycle initial strain to the nearest 0.01 mm / mm. The strain of the test specimen at the end of the cycle is defined by the strain when the load falls below the preload of 0.05 N for that cycle (during the unloading portion of the cycle) and recorded as the permanent set to the nearest 0.01 mm / mm. The entire procedure is repeated for all five replicates in the same manner.

[0151] The arithmetic mean of five replicate test specimens was calculated for each of the parameters for each of the 10 cycles and is reported as peak load in 0.01 N, normalized peak energy in 0.01 mN, normalized recovery energy in 0.01 mN, tensile stiffness in 0.01 N / mm, initial cycle strain in 0.01 mm / mm, and permanent set in 0.01 mm / mm.

[0152] Structural binding site pattern spacing and area measurements The spacing between discreet structural bond sites used to create a quilt-like pattern on the absorbent article sample, and the total area occupied by the sum of these elements in a particular region of the sample, are measured on an image of the absorbent article sample 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 an Epson Perfection V750 Pro, manufactured by Epson America Inc. (Long Beach, CA, USA), or 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 equivalent. The sample image is distance calibrated against an image of a NIST certified ruler acquired. To allow for maximum contrast, the sample is backed with a uniformly colored opaque black background before acquiring the image. All tests are performed in a conditioned room maintained at about 23±2°C and about 50±2% relative humidity.

[0153] Test samples are prepared as follows: Remove the absorbent article from any existing packaging. If the article is folded, gently unfold it, smoothing out any wrinkles. If wings are present, stretch them but leave the release paper intact. Condition the test sample at about 23° C.±2° C. and about 50%±2% relative humidity for about 2 hours prior to testing.

[0154] The images are obtained as follows: A ruler is placed on the scanner bed so that it is oriented parallel to the side of the scanner glass. An image of the ruler (calibration image) is acquired in reflection 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 sample is scanned under the same scanning conditions as follows: The test sample is placed on the center of the scanner glass and, if necessary, fixed so that the body-facing surface of the sample is flat facing the scanner glass surface. The sample is oriented so that the entire sample is within the glass surface. A black background is placed over the sample, the scanner lid is closed, and a scanned image of the entire sample is acquired with the same settings used for the calibration image. The sample image is saved as an uncompressed TIFF format file.

[0155] The sample image is analyzed as follows: The calibration image file is opened in an image analysis program, and the image resolution is calibrated using an imaged ruler to determine the number of pixels per millimeter. The sample image is then opened in an image analysis program, and the distance scale is set using the image resolution determined from the calibration image. The pattern of embossed elements present on the sample in the image is then visually inspected to identify the zones of the pattern to be analyzed. For example, an absorbent article can be divided into three equal length zones in the machine direction, such as zone 1, which is the front 1 / 3 zone, zone 2, which is the center 1 / 3 zone, and zone 3, which is the end 1 / 3 zone, by way of example. An image analysis tool is used to draw a shape along the perimeter of the first discreet zone to be analyzed. The area of ​​this first zone is measured, and a value of 0.01 mm is determined as the Zone 1 total area. 2 The area of ​​each discreet embossing element that is located inside the perimeter of Zone 1 is now measured as follows: A minimum boundary circle is drawn around each embossing element such that no part of the embossing element is located outside the boundary circle. The area of ​​the boundary circle for that embossing element is then measured and the embossing element area is recorded in 0.01 mm2 units. 2Similarly, measure the area of ​​each embossing element, including the portion of the embossing element that is located within Zone 1, and record each to the nearest 0.01 mm. 2 The area of ​​all the embossing elements in Zone 1 is then totaled and recorded in units of 0.01 mm. 2 The area is recorded in units of 0.01 mm. The Zone 1 total embossed element area is divided by the Zone 1 total area, then multiplied by 100 and recorded as the % Zone 1 total area represented by the embossed element. The spacing between each discreet embossed element inside Zone 1 is measured as follows: Measure the distance from the center of the smallest boundary circle drawn around the discreet embossed element inside Zone 1 to the center of the smallest boundary circle drawn around the closest adjacent discreet embossed element inside Zone 1 as described herein, and record this distance to the nearest 0.01 mm as the embossed spacing. Repeat similarly for all adjacent embossed elements inside Zone 1, recording each distance to the nearest 0.01 mm. The arithmetic mean of all measured embossed spacings measured between the nearest neighbors inside Zone 1 is then calculated and recorded to the nearest 0.01 mm as the Zone 1 embossed spacing.

[0156] Similarly, the entire procedure is repeated for each additional zone containing embossed elements present on the test sample and labeled accordingly as Zone 2, Zone 3, etc.

[0157] Light touch rewetting method The Light Touch Rewet Method quantitatively measures the mass of liquid that appears from a test sample of an absorbent article that has been dosed with a specific amount of Artificial Menstrual Fluid (AMF) (as described herein) when weight is applied for a specific length of time. All measurements are performed in a laboratory maintained at 23° C.±2° C. and 50%±2% relative humidity.

[0158] A syringe pump with a disposable syringe is utilized to administer the test sample. A suitable pump should be a Perfusor® Compact S (available from B. Braun) or equivalent, capable of accurately dispensing AMF at a rate of 42 ml / min. The disposable syringe is of sufficient capacity (e.g., BD Plastipak 20 mL) and is connected to a flexible tubing with an internal diameter of 3 / 16 inches (e.g., Original Perfusor® Line available from Braun, or equivalent). The AMF is prepared as described herein and brought to room temperature (23°C ± 2°C) before use in this test. Before the start of the measurement, the syringe is filled with AMF, the flexible tubing is primed with liquid, and the dispensing rate (42 ml / min) and the administration volume (4.0 mL + 0.05 mL) are verified according to the manufacturer's instructions. The flexible tubing is then attached such that it is oriented vertically above the test sample, with a distance of 19 mm between the tip of the tubing and the surface of the test sample. Of note, the AMF must be withdrawn from the syringe every 15 minutes and mixed thoroughly.

[0159] The rewet weight assembly consists of an acrylic plate and a stainless steel weight. The acrylic plate has dimensions of 65 mm x 80 mm and is approximately 5 mm thick. The stainless steel weight together with the acrylic plate has a total mass of 2 lbs (907.19 g) and applies a pressure of 0.25 psi below the surface of the acrylic plate.

[0160] For each test sample, five pieces of filter paper measuring 4 inches by 4 inches are used as the rewet substrate. Prior to testing, the filter papers are conditioned for at least two hours at 23° C.±2° C. and 50%±2% relative humidity. A suitable filter paper has a basis weight of about 139 gsm, a thickness of about 700 microns, an absorption rate of about 1.7 seconds, and is available as Ahlstrom grade 989 or equivalent from Ahlstrom-Munksjo North America LLC, Alpharetta, GA, VWR International.

[0161] Prepare the test samples as follows: Prior to testing, the test samples are conditioned at 23±2°C and 50%±2% relative humidity for at least 2 hours. The test samples are removed from all packaging, taking care not to press down or pull on the product during handling. Place the test sample horizontally on a hard, flat surface and gently smooth out any creases. Determine the test location as follows: For symmetrical samples (i.e., the front side of the sample, when divided laterally along the midpoint of the sample's longitudinal axis, is the same shape and size as the rear side of the sample), the test location is the intersection of the midpoint of the sample's longitudinal axis and the midpoint of the lateral axis. For asymmetrical samples (i.e., the front side of the sample, when divided laterally along the midpoint of the sample's longitudinal axis, is not the same shape and size as the rear side of the sample), the test location is the intersection of the midpoint of the sample's longitudinal axis and the lateral axis located at the midpoint of the sample's wings. Prepare a total of three test samples.

[0162] Place the test sample horizontally on a flat, hard surface and center the previously identified test location directly under the tip of the flexible tubing. Adjust the height of the tubing so that it is 19.0 mm above the surface of the test sample. Start the pump to dispense 4.0 mL + 0.05 mL of AMF at a rate of 42 ml / min. As soon as the AMF is completely dispensed, start a 10-minute timer. Now, obtain the mass of the five filter papers and record it to the nearest 0.001 gram as the dry mass. When the 10 minutes have elapsed, place the five pre-weighed filter papers on the test sample and center the stack over the dosing location. Then, center the acrylic plate on top of the filter papers so that the long side of the acrylic plate is parallel to the longitudinal axis of the test sample. Then, carefully lower a stainless steel weight centered over the acrylic plate and immediately start a 30-second timer. After the 30 seconds have elapsed, gently remove the rewet weight and acrylic plate and set them aside. Take the mass of five filter papers and record it to the nearest 0.001 gram as the wet mass. Subtract the dry mass from the wet mass of the filter papers and record it to the nearest 0.001 gram as the rewet. Wipe any remaining test liquid from the bottom of the acrylic plate before testing the next sample. Repeat in the same manner for a total of three replicate test samples.

[0163] The arithmetic mean of rewet among the three replicate test samples is calculated and reported to the nearest 0.001 g as "light touch rewet."

[0164] Preparation of Artificial Menstrual Fluid (AMF) Artificial menstrual fluid (AMF) is composed of a mixture of defibrinated sheep blood, phosphate buffered saline, and mucus components. AMF is prepared to have a viscosity of 7.15-8.65 centistokes at 23 °C.

[0165] The viscosity of the AMF is performed using a low viscosity rotational viscometer (a suitable instrument is a Cannon LV-2020 Rotary Viscometer with a UL adapter (Cannon Instrument Co., State College, PA) or equivalent). The appropriate size spindle for the viscosity range is selected and the instrument is operated and calibrated according to the manufacturer. Measurements are taken at 23° C.±1° C. and 60 rpm. Results are reported to the nearest 0.01 centistokes.

[0166] Reagents required for AMF preparation include defibrinated sheep blood with a hematocrit of 38% or greater (drawn under sterile conditions, available from Cleveland Scientific, Inc., Bath, Ohio, or equivalent), gastric mucin (crude form, sterile, available from American Laboratories, Inc., Omaha, Neb., or equivalent) with a target viscosity of 3-4 centistokes when prepared as a 2% aqueous solution, 10% v / v lactic acid in water, 10% w / v potassium hydroxide in water, sodium phosphate dibasic anhydrous (reagent grade), sodium chloride (reagent grade), sodium phosphate monobasic monohydrate (reagent grade), and distilled water (each available from VWR International or an equivalent source).

[0167] Phosphate buffered saline consists of two individually prepared solutions (Solution A and Solution B). To prepare 1 L of solution A, add 1.38 ± 0.005 g of sodium phosphate monobasic monohydrate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to the vessel volume. Mix thoroughly. To prepare 1 L of solution B, add 1.42 ± 0.005 g of sodium phosphate dibasic anhydrous and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to the vessel volume. Mix thoroughly. To prepare phosphate buffered saline, add 450 ± 10 mL of solution B to a 1000 mL beaker and stir at low speed on a stir plate. Insert a calibrated pH probe (accurate to 0.1) into the beaker of Solution B and add, with stirring, enough Solution A to bring the pH to 7.2±0.1.

[0168] The mucus component is a mixture of phosphate buffered saline, aqueous potassium hydroxide, gastric mucin, and aqueous lactic acid. The amount of gastric mucin added to the mucus component directly affects the final viscosity of the prepared AMF. To determine the amount of gastric mucin required to obtain an AMF within the target viscosity range (7.15-8.65 centistokes at 23°C), three batches of AMF with various amounts of gastric mucin in the mucus component are prepared, then a least squares linear fit through the three points is performed and the exact amount required is interpolated from the concentration vs. viscosity curve. A good range for gastric mucin is usually 38-50 grams.

[0169] To prepare approximately 500 mL of mucus component, add 460±10 mL of pre-prepared phosphate buffered saline and 7.5±0.5 mL of 10% w / v aqueous potassium hydroxide solution to a 1000 mL sturdy glass beaker. Place the beaker on a stirring hot plate and bring the temperature to 45°C±5°C while stirring. Weigh out a predetermined amount of gastric mucus (±0.50 g) and slowly sprinkle into the pre-prepared liquid at 45°C to avoid clumping. Cover the beaker and continue mixing. Allow the temperature of the mixture to exceed 50°C but not exceed 80°C for 15 minutes. Continue heating with gentle stirring while maintaining this temperature range for 2.5 hours. After 2.5 hours, remove the beaker from the hot plate and allow to cool to less than 40°C. Then add 1.8±0.2 mL of 10% v / v aqueous lactic acid solution and mix thoroughly. Autoclave the mucilage component mixture at 121°C for 15 minutes and allow to cool for 5 minutes. Remove the mucilage component mixture from the autoclave and stir until the temperature reaches 23°C ± 1°C.

[0170] Allow the temperature of the sheep blood and mucus components to be 23 °C ± 1 °C. Using a 500 mL graduated cylinder, measure the volume of the entire batch of previously prepared mucus components and add that volume to a 1200 mL beaker. Add an equal volume of sheep blood to the beaker and mix thoroughly. Using the viscosity method previously described, verify that the viscosity of the AMF is 7.15 - 8.65 centistokes. If not, discard the batch and adjust the mucus components as necessary to make another batch.

[0171] Certified AMF must be refrigerated at 4°C unless intended for immediate use. AMF may be stored in an airtight container at 4°C for a maximum of 48 hours after preparation. Prior to testing, AMF must be at 23°C ± 1°C. After testing is completed, any unused portion is discarded.

[0172] Thickness-Pressure Method The thickness of a test sample is measured as the distance between a reference platform on which the sample rests and a presser foot that exerts a specific amount of pressure on the sample for a specific period of time. For purposes herein, thickness is measured at two different confining pressures (7 g / cm 2 and 70g / cm 2 All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity and test specimens are conditioned in this environment for at least two hours prior to testing.

[0173] The thickness is measured at a constant pressure (7g / cm 2 and 70g / cm 2 ) is measured with a manual micrometer equipped with a footrest capable of applying pressure to the test sample. The manual micrometer is a dead weight instrument with an accurate reading to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic available from VWR International, or equivalent. The footrest is a flat grounded circular movable surface having a diameter smaller than the test sample and capable of applying the required pressure. A suitable footrest has a diameter of 25.4 mm, although smaller or larger footrests can be used depending on the size of the sample being measured. The test sample is supported by a horizontal flat reference platform larger than and parallel to the surface of the footrest. The system is calibrated and operated according to the manufacturer's instructions.

[0174] If necessary, obtain the test sample by removing it from the absorbent article. When cutting the test sample from the absorbent article, care is taken not to contaminate or deform any of the test sample layers in the process. The test sample is obtained from an area that does not contain folds or wrinkles and should be larger than the presser foot.

[0175] 7g / cm 2To measure thickness at a confining pressure of 7 g / cm, first zero the micrometer against a horizontal flat reference platform. Place the test specimen on the platform with the test location centered under the presser foot. Gently lower the presser foot at a downward speed of 3.0 mm ± 1.0 mm / sec until full pressure is applied to the test specimen. After waiting 5 seconds, record the thickness of the test specimen to the nearest 0.001 mm. Repeat similarly for a total of 10 replicate test specimens. 2 Calculate the arithmetic mean of all thickness measurements taken at a confining pressure of 7 g / cm 2 The thickness is reported to the nearest 0.01 mm.

[0176] 70g / cm 2 To measure thickness at a confining pressure of 70g / cm, first zero the micrometer against a horizontal flat reference platform. Place the test specimen on the platform with the test location centered under the presser foot. Gently lower the presser foot at a downward speed of 3.0mm ± 1.0mm / sec until full pressure is applied to the test specimen. After waiting 5 seconds, record the thickness of the test specimen to the nearest 0.001mm. Repeat similarly for a total of 10 replicate test specimens. 2 Calculate the arithmetic mean of all thickness measurements taken at a confining pressure of 70 g / cm 2 The thickness is reported to the nearest 0.01 mm.

[0177] Pore ​​Volume Distribution (PVD) Method Pore ​​volume distribution determines the estimated porosity of the effective pores in a porous test sample by measuring the fluid movement in and out of the sample as stepwise controlled pressure differentials are applied to the sample in the sample chamber. The incremental and cumulative amounts of fluid absorbed / exhausted by the porous sample at each pressure are then determined. The work done by the porous sample normalized by the area of ​​the sample is then calculated as the capillary work potential.

[0178] Principle of the method For a uniform cylindrical pore, the radius of the pore is related to the pressure differential required to fill or empty the pore by the following equation: Differential pressure = [2γcosΘ)] / r where γ=liquid surface tension, Θ=contact angle, and r=pore radius.

[0179] The pores contained in natural and manufactured porous materials are often thought of in terms such as voids, holes, or conduits, and these pores are generally not perfectly cylindrical or all uniform. Nevertheless, the above formula can be used to relate the differential pressure to the effective pore radius, and by monitoring liquid movement into and out of the material as a function of the differential pressure, the effective pore radius distribution in the porous material can be characterized. (This general methodology may not produce results that are exactly consistent with measurements of pore dimensions obtained by other methods, such as microscopy, since non-uniform pores are approximated as uniform by the use of effective pore radius.)

[0180] The pore volume distribution method uses the above principles and is implemented using the apparatus and techniques described in "Liquid Porosimetry: New Methodologies and Applications" by B. Miller and I. Tyomkin published in The Journal of Colloid and Interface Science (1994), volume 162, pages 163-170, which is incorporated herein by reference. The method relies on measuring the increment in liquid volume entering or leaving a porous sample as the air pressure difference between the ambient ("lab") air pressure and a slightly elevated air pressure (positive pressure difference) surrounding the sample in a sample test chamber is changed. The sample is introduced into a dry sample chamber, which is controlled at a sufficient positive pressure difference (relative to the laboratory) to prevent fluid uptake into the sample after the fluid bridge is opened. After opening the fluid bridge, the air pressure difference is gradually reduced to zero, and in the process a subpopulation of pores in the sample captures liquid according to their effective pore radius. After reaching the minimum differential pressure where the mass of fluid in the sample is greatest, the differential pressure is again increased in steps toward the starting pressure and liquid is expelled from the sample. The absorption portion of the stepped sequence begins at the maximum differential pressure (smallest corresponding effective pore radius) and ends at the minimum differential pressure (largest corresponding effective pore radius). The exhaust portion of the sequence begins at the minimum pressure difference and ends at the maximum pressure difference. After correcting for any fluid movement for each particular pressure step measured on the chamber while emptying the entire absorption / exhaust sequence, the fluid uptake by the sample (mg) at each differential pressure and the cumulative volume ((mm 3 / mg) is determined by this method.

[0181] Sample preparation and conditioning The pore volume distribution method is performed on specimens obtained from material samples conditioned for at least 2 hours in a room maintained at a temperature of 23°C ± 2.0°C and a relative humidity of 50% ± 2%, and all tests are performed in such conditioned room under the same environmental conditions. The conditioned specimens described herein are considered dry for the purposes of this invention. If necessary, test materials are obtained by cutting from the absorbent article. When cutting the test material, the process is ensured to not contaminate or deform any of the material layers. Test specimens are cut from areas of the test material that do not contain folds or wrinkles. Determine which side of the sample is intended to face the wearer during use, and then cut the sample to 55 mm long by 55 mm wide. The mass of the sample is measured and recorded to the nearest 0.1 mg. Three samples are measured for any given test material, and the results of these three replicates are averaged to obtain the final reported value.

[0182] Device A suitable apparatus for this method is described in "Liquid Porosimetry: New Methodology and Applications" by B. Miller and I. Tyomkin published in The Journal of Colloid and Interface Science (1994), volume 162, pages 163-170. 2 0~1098mm H 2Any pressure control scheme capable of controlling a sample chamber pressure of zero differential pressure may be used in place of the pressure control subsystem described in this reference. An example of a suitable overall instrument and software is the TRI / Autoporosimeter (Textile Research Institute (TRI) / Princeton Inc. of Princeton, NJ, USA). The TRI / Autoporosimeter is an automated computer-controlled instrument for measuring the pore volume distribution (e.g., the volume of pores of different sizes within the effective pore radius range of 5 μm to 1200 μm) of porous materials. Computer programs such as Automated Instrument Software Releases 2000.1 or 2003.1 / 2005.1 or 2006.2, or Data Treatment Software Release 2000.1 (available from TRI Princeton Inc.), and spreadsheet programs may be used to collect and analyze the measured data.

[0183] A schematic of a suitable instrument is shown in Figure 11. The instrument consists of a balance 4800 having a fluid reservoir 4802 in direct fluid communication with a sample 4805 present in a sealed, air-pressurized sample chamber 4810. Fluid communication between the reservoir 4802 and the sample chamber 4810 is controlled by a valve 4815. A weight 4803 placed on top of a plexiglass plate 4804 (55mm long x 55mm wide) is used to apply a confining pressure of 0.25 psi on the test sample to ensure good contact between the sample and a fluid-saturated membrane 4806 throughout the test. Membrane 4806 (90 mm diameter, 150 um thickness, 1.2 μm pore size; mixed cellulose ester filter RAWP09024; available from Millipore Corporation of Bedford, MA) is attached to macroporous frit 4807 (90 mm diameter, 60 mm thick Monel plate, available from Mott Corporation, Farmington, CT, or equivalent) as follows: Membrane 4806 is adhered to frit 4807 using Krylon® spray paint (Gloss White Spray Paint #1501, available from FilmTools, or equivalent) as an adhesive. The prepared membrane / frit assembly is allowed to dry before use.

[0184] To prepare the device for testing, fill the inner base 4812 of the sample chamber 4810 with the test fluid. The test fluid is 9.0 g of reagent grade NaCl (liquid density 1.01 g / cm3) per 1 L of deionized water. 3The membrane / frit assembly is placed membrane 4806 side onto the inner base 4812 of the sample chamber 4810 and it is secured in place with the locking collar 4809. The reservoir 4802 and connecting tube 4816 are filled with the test fluid. The valve 4815 is opened to ensure that no air bubbles are trapped in the connecting tube or in the pores in the membrane / frit assembly. The feet 4811 of the sample chamber 4810 are used to level the sample chamber as necessary, adjusting the height of the sample chamber (and / or the amount of fluid in the reservoir 4802) so that the top of the membrane 4806 is in the same horizontal plane as the top of the fluid in the reservoir 4802.

[0185] The step differential pressure (mmH 2 0) program the system to progress through the following sequence: 1098, 549, 366, 275, 220, 183, 137, 110, 92, 78, 69, 61, 55, 50, 46, 42, 39, 37, 34, 32, 31, 29, 27, 24, 22, 20, 18, 14, 9.2, 6.9, 5.5, 4.6, 5.5, 6.9, 9.2, 14, 18, 20, 22, 24, 27, 29, 31, 32, 34, 37, 39, 42, 46, 50, 55, 61, 69, 78, 92, 110, 137, 183, 220, 275, 366, 549, 1098. These pressures are 5 μm (1098 mmH 2 0)~1200μm(4.6mmH 2 0) The criterion for moving from one pressure step to the next is that the fluid uptake / exhaust from the sample is less than 10 mg / min for 15 seconds as measured by Balance 4800.

[0186] Method Steps The system can be checked for leaks and ensured to reach the maximum test pressure as follows: Open liquid valve 4815, place top 4808 of sample chamber 4810 in place and seal the chamber. Apply sufficient air pressure to chamber 4810 (via connection 4814) to achieve 1098 mm H 2 A differential pressure of 0 (effective pore radius of 5 μm) is achieved. The liquid valve 4815 is closed and then the sample chamber is opened. The sample 4805 (wearer side facing down) is placed directly on the membrane 4806 and then the cover plate 4804 and restraining weight 4803 are centered over the sample. The top 4808 is replaced and the sample chamber 4810 is resealed. The liquid valve 4815 is opened to allow fluid transfer between the liquid reservoir 4802 and the sample, progressing the test through a pre-specified sequence of differential pressures. The amount of fluid absorbed (or expelled) by the sample at each pressure step throughout the sequence is recorded as uptake to the nearest 0.1 mg.

[0187] A separate "blank" measurement is performed following this same method procedure (same stepwise sequence of differential pressure) on an empty sample chamber that has no sample 4805, cover plate 4804, or restraining weight 4803 present on the membrane / frit assembly. Any fluid movement observed is recorded (in mg) at each of the pressure steps. The sample fluid uptake data is corrected for any fluid movement associated with the empty sample chamber by subtracting the fluid uptake value of this "blank" measurement from the corresponding value in the sample measurement, and recorded to the nearest 0.1 mg as the blank-corrected sample uptake.

[0188] Determination of % Saturation, Cumulative Volume and Capillary Action Potential The percent saturation of the sample at each pressure step in both the uptake and exhaust portions of the test sequence can be calculated by dividing the maximum blank-corrected sample uptake (mg) by the blank-corrected sample uptake (mg) and then multiplying by 100.

[0189] The cumulative volume is calculated from each of the pressure steps by the following formula: Cumulative volume (mm 3 / mg) = blank-corrected sample uptake (mg) / fluid density (g / cm 3 ) / mass of sample (mg) The capillary action potential (CWP) is the work done by the sample normalized by the area of ​​the sample for the absorption portion of the test sequence. The trapezoidal rule is used to integrate the i pressure as a function of the accumulated volume over n data points for the absorption portion of the cycle.

[0190]

number

[0191] CWP: 1mJ / m 2 Repeat the measurement on a total of three replicate test samples in the same manner. Calculate the arithmetic mean of the CWP between the three replicate test samples and record it in mJ / m 2 Report as CWP per unit.

[0192] Wetting Penetration Time Method Wetting penetration time measurements are performed using a drop experiment. A specific amount of Paper Industry Fluid (PIF); formulations provided separately herein) is applied to the surface of the test sample using an automated liquid delivery system. A high-speed video camera captures time-stamped images of the drop at a rate of 125 frames per second. The time elapsed from the time the drop first contacts the surface of the test sample until the drop is completely absorbed into the test sample is measured. Wetting penetration time is determined as the time it takes for the contact angle of the drop absorbed into the test sample to decrease to a contact angle of <10°. The contact angle between the drop and the surface of the test sample is determined by image analysis software. All measurements are performed at a constant temperature (23°C ± 2°C) and relative humidity (50% ± 2%).

[0193] To perform this test, an automated contact angle tester is required. The system includes a light source, a video camera, a horizontal sample stage, a liquid delivery system with a pump and a microsyringe, and a computer with suitable software for video image capture, image analysis, and reporting of contact angle data. A suitable instrument is the Optical Contact Angle Measurement System OCA 20 (DataPhysics Instruments, Germany), or equivalent. The system must be capable of delivering a 35 microliter droplet and capturing images at a rate of 125 frames per second. Unless otherwise specified in this test procedure, the system is calibrated and operated according to the manufacturer's instructions.

[0194] Sample preparation To obtain a test specimen for measurement, a single layer of dry substrate material is laid flat and a rectangular test sample is cut out, 15 mm wide and approximately 70 mm long. The width of the sample can be reduced as necessary to ensure that the test area of ​​interest is not obscured by surrounding features during testing. Care should be taken with narrow sample pieces so that droplets do not reach the edge of the test specimen during testing, otherwise the test must be repeated. When selecting the location to sample, care should be taken to avoid folds, wrinkles, or tears. If the substrate material is a layer of an absorbent article, such as a topsheet or outer cover nonwoven material, acquisition layer, distribution layer, or other component layer, tape the absorbent article to a hard flat surface to form a planar configuration. Carefully separate the individual substrate layers from the absorbent article. If necessary, a scalpel and / or a cryo-spray (such as Cyto-Freeze from Control Company, Houston Tex.) can be used to remove the substrate layer from further underlying layers to avoid longitudinal and lateral stretching of the material. Once the substrate layer has been removed from the absorbent article, proceed to cut the test specimens as described above. Prior to testing, pre-condition the test specimens for 2 hours at 23°C ± 2°C and 50% ± 2% relative humidity.

[0195] Test procedure The test sample is placed on a horizontal sample stage with the test side (facing the wearer) facing up and the test area within the field of view of the camera under the needle of the liquid delivery system. The test sample is fixed so that it is flat but not taut, and all interaction between the droplet and the underlying surface is avoided to prevent excessive capillary forces. A 14-gauge blunt-tip stainless steel needle (ID 1.600 mm, OD 1.820 mm; available from IntelliSpense, or equivalent) is placed above the test sample such that at least 2 mm of the needle tip is within the field of view of the camera. The sample stage is adjusted so that there is a distance of approximately 7 mm between the tip of the needle and the surface of the test sample. A 35-microliter droplet of PIF is formed at a rate of 1 microliter / second and allowed to free-fall onto the surface of the test sample. Video image capture is initiated before the droplet contacts the surface of the test sample, and then a continuous series of images are collected until the droplet of PIF is fully absorbed into the test sample over a period of up to 60 seconds after the droplet contacts the surface of the test sample. This procedure is repeated for a total of five substantially similar replicate test areas. Use a new test sample or ensure that the wetted area of ​​the previous drop is avoided during subsequent measurements. On each image captured by the video camera, the test sample surface and the outline of the drop are identified and used in image analysis software to calculate the contact angle to within 0.1 degrees. The contact angle is the angle formed by the surface of the test sample and is tangent to the surface of the drop in contact with the test sample. For each series of images from the test, time zero is the time at which the drop contacts the surface of the test sample. Wetting penetration time is defined as the time it takes for the contact angle of a drop absorbed into the test sample to decrease to a contact angle of <10°. Wetting penetration time is measured by identifying the first image in a given series where the contact angle has decreased to a contact angle of <10°, and then calculating and reporting the amount of time that has elapsed since time zero based on that image. If a contact angle of less than 10° is not reached within 60 seconds, the wetting penetration time is reported as 60 seconds. Similarly, wetting penetration time is determined for each of the five replicate test areas. The arithmetic mean of the wetting penetration time of the five replicate test areas is calculated and this value is reported to the nearest 0.1 millisecond.

[0196] Preparation of Paper Industry Fluid (PIF) Paper Industry Fluid (PIF) is a widely accepted non-toxic, non-blood-based surrogate fluid for human menstrual blood. PIF is an aqueous mixture of sodium chloride, carboxymethylcellulose, glycerol, and sodium bicarbonate, with the surface tension adjusted by the addition of a non-ionic surfactant. This standard test fluid was developed by the technical committee of the French Industrial Group of Manufacturers of Menstrual Products (Groupment Francaise de producteurs d'articles pour usage sanitaires et domestiques) and is described in the AFNOR standard, Normilization francaise Q34-018 of September 1994. When properly prepared, PIF has a viscosity of 11+1 centipoise at a temperature of 23°C ± 1°C, a surface tension of 50+2 mN / m, and a pH value of 8+1.

[0197] The viscosity of the prepared PIF is performed using a low viscosity rotational viscometer (a suitable instrument is a Cannon LV-2020 Rotary Viscometer with a UL adapter (Cannon Instrument Co., State College, PA), or equivalent). The appropriate size spindle for the viscosity range is selected, and the instrument is operated and calibrated according to the manufacturer's instructions. Measurements are taken at 23° C.±1° C. and 30 rpm. Results are reported to the nearest 0.1 centipoise.

[0198] The surface tension of the prepared PIF is carried out using a tensiometer. A suitable instrument is a Kruss K100 (available from Kruss GmbH, Hamburg, Germany) using the plate method, or equivalent. The instrument is run and calibrated according to the manufacturer's instructions. Measurements are taken when the aqueous mixture is at a temperature of 23° C.±1° C. Results are reported to the nearest 0.1 mN / m.

[0199] The reagents required for PIF preparation include sodium chloride (reagent grade solid), carboxymethylcellulose (>98% purity, mass fraction), glycerol (reagent grade liquid), sodium bicarbonate (reagent grade solid), a 0.25 wt% solution of polyethylene glycol tert-octylphenyl ether in water (Triton™ X-100, reagent grade), and deionized water, each of which is available from VWR International or an equivalent source.

[0200] The following preparation steps result in approximately 1 liter of PIF. Add 80.0+0.01g of glycerol to a 2L glass beaker. The amount of carboxymethylcellulose (CMC) directly affects the final viscosity of the prepared PIF, so the amount of CMC is adjusted to result in a final viscosity within the target range (11+1 centipoise). While stirring, slowly add (in 15-20 gram amounts) the carboxymethylcellulose to the beaker of glycerol to minimize clumping. Continue stirring for approximately 30 minutes or until all of the CMC has dissolved and no clumps remain. Now add 1000+1g of deionized water to the beaker and continue stirring. Next, while stirring, add 10.0+0.01g of sodium chloride and 4.0+0.01g of sodium bicarbonate to the beaker. The amount of non-ionic surfactant solution (0.25 wt% Triton™ X-100 aqueous) directly affects the final surface tension of the prepared PIF, so the amount of 0.25 wt% Triton™ X-100 is adjusted to yield a final surface tension within the target range (50 + 2 mN / m). The total amount of 0.25 wt% Triton X-100 solution to add to the beaker is approximately 3.7 mL.

[0201] Ensure that the temperature of the prepared PIF is 23° C.±1° C.; Ensure that the viscosity is 11+1 centipoise and the surface tension is 50+2 mN / m using the viscosity and surface tension methods described above; Measure the pH of the prepared PIF using pH strips or a pH meter (any convenient source) and ensure that the pH is within the target range (8+1). If the batch of prepared PIF does not meet the specified targets, it is discarded and another batch is made, adjusting the CMC and amount of 0.25 wt % Triton™ X-100 solution as necessary.

[0202] Batches of qualified PIF are stored covered at 23° C. ±1° C. Viscosity, surface tension, and pH are tested daily prior to use to ensure the mixture meets the specified targets for each parameter.

[0203] Transmittance measurement method This method allows the calculation of the permeability (in Darcy) of a material through the measurement of the downward movement of the test fluid through the test sample along the z-direction (vertical) over a range of downward heads indicated by the decrease in height of the test fluid in the vessel. The decreasing height of the test fluid in the vessel is measured repeatedly over time during the procedure as the fluid passes through the test sample and drains out the bottom of the vessel. From the data collected along with the relevant dimensions of the part of the apparatus through which the fluid moves, the measured wet caliper of the test sample, constants related to gravity and the properties of the selected test fluid, flow rate and permeability can be calculated. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the test samples are conditioned in this environment for at least 2 hours prior to testing.

[0204] Equipment components The measurement device 6000 and its components are shown in Figures 12A-14. With reference to Figure 12A, the device 6000 includes a cylindrical fluid container 6010 including a cylindrical wall 6010a having a fitted lid 6020 and a base 6030 sealingly fitted to the bottom of the wall 6010a to form the fluid container 6010, a fluid level sensor 6060 fitted to and penetrating the lid 6020, a valve 6070 housed within a valve body 6080, and a valve actuator 6100 mechanically associated with the valve via a linkage 6090.

[0205] The cylindrical wall has an inside height Hfv of 200 mm to the bottom of the lid, an inside diameter of 3-7 / 8 inches (98.425 mm), a wall thickness of 3 / 8 inches (9.525 mm), and an outside diameter of 4-5 / 8 inches (117.48 mm). The lid 6020 is suitably attached so that it rests stably on top of the cylindrical wall, but should not be sealingly attached thereon, and is drilled with one or more vent holes (not shown) therethrough to prevent negative pressure / vacuum from building up in the fluid container as the test fluid is drained from the fluid container. The purpose of the lid 6020 is to hold and suspend the fluid height sensor 6060 above the test fluid surface, not to seal the top of the container.

[0206] 12A, the base 6030 has flat, parallel upper and lower surfaces, the upper surface of which is sealingly attached to the bottom of the wall 6010a. The base 6030 is suitably formed or machined to define a sample chamber therein having a cylindrical upper chamber portion 6030a, a cylindrical middle chamber portion 6030b, and a cylindrical lower chamber portion 6030c. The three cylindrical chamber portions are coaxial along the vertical / z direction.

[0207] The heights and inner diameters of the three chamber sections are as follows: Height Huc of upper chamber portion 6030a: 9.5mm; Inner diameter Duc of upper chamber portion 6030a: 40 mm; Height Hmc of middle chamber portion 6030b: 12.5mm; Inner diameter Dmc of middle chamber portion 6030b: 30mm; The height Hlc of the lower chamber portion 6030c: 20 mm; and Inner diameter Dlc of lower chamber portion 6030a: 26 mm.

[0208] A valve body 6080 having a valve 6070 is attached to the underside of the base 6030, below the lower open end of the lower chamber 6030c. The valve 6070 is configured to be rapidly actuated between a fully closed position and a fully open position, in which the entire lower chamber portion 6030c is opened, allowing fluid to move freely downward therefrom without any restriction by the valve 6070. The valve 6070 may be a flat horizontal sliding member having a circular opening port of at least 26.0 mm diameter, through which it is linearly moved to a position below the lower chamber portion 6030c upon actuation to the open position. Alternatively, the valve 6070 and valve body 6080 may have any other suitable configuration adapted to be rapidly moved between a fully closed position and a fully open position, and when in the fully open position, the valve does not present any impediment to fluid flow downward and out of the lower open end of the lower chamber portion 6030c. The valve 6070 and actuator 6100 are configured to actuate from a fully closed position to a fully open position, and vice versa, within 10 milliseconds for either movement. The actuator 6100 may include a solenoid or any other suitable mechanism adapted for this purpose.

[0209] The cylindrical wall 6010a, the lid 6020, the base 6030, and optionally the valve body 6080 and the valve 6070 are fabricated and machined from polished clear cast acrylic plastic (poly(methyl methacrylate) (PMMA)) stock (known brands include, but are not limited to, PLEXIGLAS and LUCITE), which are available in a variety of precast tube, rod / bar, disk, sheet and block forms from various suppliers of such materials, such as McMaster-Carr Supply Company (Elmhurst, Illinois). For the tubing used to form the wall 6010a, tubing with an inner diameter Dfv that varies slightly from the inner diameter Dfv specified herein, depending on availability, may be selected. In such cases, it will be recognized that the corresponding value of the radius r of the fluid enclosure in the following equation should be modified to reflect the actual diameter Dfv of the tubing used.

[0210] The fluid height sensor 6060 is an ultrasonic height sensor such as part #098-10060 ML series, airborne continuous transmitter with an accuracy of approximately +0.2 mm (TE Connectivity, Schaffhausen, Switzerland and Berwyn, Pennsylvania, USA) or equivalent, and is interfaced to a computer running software capable of collecting fluid height versus time data throughout the test at a rate of 100 Hz. The fluid height sensor 6060 continuously transmits a signal indicative of the height of the test fluid in the fluid container 6010 during the measurement procedure.

[0211] The apparatus further includes a support structure, which may include a support platform 6110 and height adjustable legs 6120, or any other suitable support structure, configured to stably hold the container and valve assembly above the collection container 6130, with the longitudinal axis of the cylindrical wall 6010a vertical / plumb and the bottom of the base 6030 horizontal. If included, the support platform 6110 must include an opening or otherwise be configured so as not to obstruct the bottom end of the lower chamber portion 6030c or the fluid exit from the valve 6070 and valve body 6080.

[0212] The measurement device further includes a collection container 6130 of any suitable shape, size, and material composition suitable for receiving and stably containing the entire volume of the test fluid used in the method, and which fits easily beneath the support structure.

[0213] The measurement device further includes a sample weight 6040, which is machined from stainless steel to the configuration and dimensions shown in Figures 13A-13C.

[0214] The measurement apparatus further includes a sample support 6050 having the configuration and dimensions shown in FIG. 14. The sample support 6050 has a z-direction caliper (height when placed in position in the measurement apparatus in preparation for the measurement procedure) of 0.75 mm. Each of the concentric ring portion 6050a and radial spoke portions 6050b of the sample support 6050 shown in FIG. 14 has an xy-planar width of 0.75 mm and a square cross section. The sample support 6050 is configured to support the test specimen 6160 within the middle chamber portion 6030b of the base 6030. The sample support 6050 may be cut or machined from any material of suitable strength and corrosion resistance, such as, for example, brass sheet stock.

[0215] It is noted that the outer diameter of the sample support 6050 and the inner diameter of the intermediate chamber portion 6030b are both defined above to be 30.0 mm. The sample support 6050 is disposed within the intermediate chamber 6030b during the measurement procedure. It is therefore understood that either or both of the inner diameter of the intermediate chamber portion 6030b and the outer diameter of the sample support 6050 may require slight adjustment to provide a small but sufficient clearance to allow the sample support 6050 to be conveniently inserted into and withdrawn from the intermediate chamber portion 6030b.

[0216] Similarly, it is noted that the outer diameter of the lower portion of the sample weight 6040 and the inner diameter of the middle chamber portion 6030b are both specified above to be 30.0 mm, and the outer diameter of the upper portion of the sample weight 6040 and the inner diameter of the upper chamber portion 6030a are both specified to be 40.0 mm. During a measurement procedure, the lower portion of the sample weight 6040 is disposed within the middle chamber portion 6030b, and the upper portion of the sample weight 6040 is disposed within the upper chamber portion 6030a. Thus, it is understood that either or both of the inner diameter of the middle chamber portion 6030b and the outer diameter of the lower portion of the sample weight 6040, and either or both of the inner diameter of the upper chamber portion 6030a and the outer diameter of the upper portion of the sample weight 6040, may require slight adjustment to provide a small but sufficient clearance to allow the sample weight 6050 to be conveniently inserted into and withdrawn from the middle chamber portion 6030b.

[0217] The measurement device further includes a computer (not shown) having appropriate software and interface equipment configured to communicate with the valve actuator 6100 to open and close the valve 6070, and to receive and collect fluid height data from the fluid height sensor 6060 over time at a rate of 100 Hz. One of ordinary skill in the art will have sufficient knowledge and / or resources readily available to obtain the components and configure a system including a computer and software to perform the operations described herein.

[0218] Preparation of test fluids The test fluid is an aqueous solution, which is prepared as follows:

[0219] The test fluid is an aqueous solution containing low viscosity carboxymethylcellulose (CMC) sodium salt. The concentration of CMC salt added to deionized water is adjusted so that the resulting solution has a viscosity of 8 + 0.3 centipoise at a temperature of 23°C ± 1°C.

[0220] The viscosity of the prepared test fluids is performed using a low viscosity rotational viscometer (a suitable instrument is a Cannon LV-2020 Rotary Viscometer with a UL adapter (Cannon Instrument Co., State College, Pennsylvania) or equivalent). The appropriate size spindle for the viscosity range is selected and the instrument is operated and calibrated according to the manufacturer's instructions. Measurements are taken at 23° C.±1° C. and 30 rpm. Results are reported to the nearest 0.1 centipoise.

[0221] The components required for the test fluid preparation are carboxymethylcellulose sodium salt (low viscosity, reagent grade, CAS 9004-32-4) and deionized water. CMC salt is available from any convenient source, for example, Merck KgaA / Sigma Aldrich (Burlington, Massachusetts), part number C5678.

[0222] The following preparation steps result in approximately 2.5 liters of test fluid. The amount of CMC salt directly affects the final viscosity of the prepared test fluid, so the amount of CMC salt is adjusted to result in a final viscosity within the target range (8.0±0.3 centipoise). The amount of CMC salt needed to reach 8 cP may vary from batch to batch. Additions of CMC salt in the range of 30g-40g are usually successful, but lesser or greater amounts may be required. Add 2550 grams of deionized water to a 3L beaker. While stirring, slowly add the CMC salt to the beaker (start with 15 grams) to minimize clumping. Continue stirring for approximately 30 minutes or until all of the CMC is dissolved and no lumps remain.

[0223] Ensure that the temperature of the prepared test fluid is 23°C ± 1°C. Measure the viscosity using the viscosity measurement procedure described above. The target is 8 + 0.3 centipoise. If the prepared batch of test fluid does not meet the target, add more deionized water if the viscosity is too high, or add more CMC salt in small increments if the viscosity is too low. Measure the viscosity again and repeat the content adjustment and measurement process until the target viscosity is reached.

[0224] Qualified batches of test fluid are stored covered at 23°C ± 1°C. Viscosity is tested daily prior to use to ensure the fluid meets specified targets.

[0225] procedure To obtain the test sample for measurement, a single layer of the dry subject material is laid flat on a horizontal work surface and a circular test sample 30 mm in diameter is punched out from it. In selecting the location for sampling, avoid areas of the material that have folds, wrinkles or tears.

[0226] If the target material is a layer component of an absorbent article (e.g., a feminine hygiene pad), such as a topsheet or absorbent layer component, obtain a representative sample of the target material that is not incorporated into an absorbent article. Alternatively, if only a fully manufactured absorbent article is available as the source of the target material, from that example, separate the target layer component from the article without stretching or damaging it. Once the target layer component is removed from the article, punch out the test specimen as described above. Precondition the test specimen for 2 hours at 23°C ± 2°C and 50% ± 2% relative humidity before testing.

[0227] 12B, with the fluid valve 6070 in the closed position, the sample support 6050 is inserted into the middle chamber portion 6030b so that it sits horizontally / flat on the lower circumferential lip of the middle chamber portion 6030b. Using tweezers, the test sample 6160 is gently placed on top of the sample support 6050 and laid flat so that there are no wrinkles. The sample weight 6040 is then gently placed over / onto the test sample 6160 such that the lower portion of the sample weight 6040 is inserted into the middle chamber portion 6030b and rests on the test sample around its periphery, and the upper portion of the sample weight 6040 is nested within the upper chamber portion 6030a.

[0228] Next, the pre-prepared test solution is slowly added to the fluid container 6010 until it reaches an initial fluid surface 6140 height Hi of 150 mm above the top surface of the test sample 6160 .

[0229] Allow the test sample 6160 to equilibrate in the filled sample chamber for approximately 60 seconds, ensuring that there are no air bubbles on the surface of the test fluid or on the surface of the test sample. If air bubbles are present on the fluid surface, use a clean instrument to remove or pop them. If air bubbles are present on the top surface of the test sample 6160, gently remove the bubbles using a clean blunt-tip laboratory stir stick, taking care not to remove the fibers (if the test sample is fibrous) or stretch or damage the test sample.

[0230] The fluid height sensor 6060 is secured to the lid 6020, which is then positioned and fitted over the cylindrical wall 6010a. Adjust the position of the fluid height sensor 6060, if necessary, before the start of the test to prevent the fluid height sensor 6060 from contacting the starting surface of the test fluid. Initially, the bottom tip of the sensor 6060 should be approximately 170 mm from the top surface of the test sample 6160.

[0231] A collection vessel 6130 is placed below the valve 6070 .

[0232] 12C, to start the measurement, the valves 6070 are simultaneously opened and begin acquiring decreasing fluid height Hd and time data in 0.01 mm and 0.01 sec increments, respectively, at a data acquisition rate of 100 Hz. The test fluid flows under gravity through the sample chamber, through the test specimen 6160, the sample support 6050, and the release valve 6070, into the collection vessel 6130, causing the test fluid surface 6140 to drop and the collected fluid surface 6150 to rise. The height sensor 6060 senses and transmits data regarding the height of the test fluid surface 6140 over time at a specified sensing frequency. The measurement ends and the valve 6070 is closed when no more test fluid exits the valve or after 1,000 seconds have elapsed, whichever occurs first. The lid 6020 is removed. Lift the sample weight 6040 out of the sample chamber and using tweezers gently remove the wet test specimen 6160 from the sample chamber and proceed to measure the wet caliper of the test specimen.

[0233] The wet caliper of the test specimen 6160 is measured immediately after the completion of the measurement procedure using a manual micrometer equipped with a tail capable of exerting a steady pressure of 2.07 kPa + 0.07 kPa. The manual micrometer is a deadweight instrument with an accurate reading to 0.01 mm. A suitable instrument is a Mitutoyo Series 543 ID-C Digimatic, available from Avantor / VWR International, Radnor, Pennsylvania, or equivalent. The foot is a flat circular movable surface with a diameter of 19 mm. The test specimen is supported by a horizontal flat reference platform that is larger than and parallel to the surface of the foot. The micrometer is zeroed against the horizontal flat reference platform. The wet test specimen 6160 is transferred to the micrometer reference platform so that the specimen 6160 is centered and rests horizontally and flat under the foot. The pressure force is manually lowered at a rate of 3+1 mm / s until the full pressure (2.07 kPa) is applied to the test specimen. After 5 seconds, the caliper of the wet test specimen is recorded to the nearest 0.01 mm as the specimen caliper. The test specimen is then discarded.

[0234] Any remaining test fluid in the fluid container 6010 and sample chamber is removed.

[0235] This procedure is repeated for a total of three replicate test samples.

[0236] A separate "blank" run measurement is performed by following the procedure above, but with only the sample support 6050 and sample weight 6040 present in the sample chamber (i.e., no test sample is present). Note that the initial test fluid height Hi is 150 mm above the top surface of the sample support 6050, not the surface of the sample. This blank measurement allows the permeability of the sample support 6050 to be taken into account when calculating the permeability of the test sample.

[0237] Transmittance calculation Total transmittance k totalis the permeability of the test sample plus the sample support, calculated from the time and volume of flow through a decrease in fluid height from 150 mm of test fluid to 130 mm of test fluid. The total permeability was calculated for each replicate test sample using the following formula and was calculated to be within 0.01E -10 m 2 Record in units.

[0238]

number

[0239]

number

[0240] Permeability k of sample support 6050 ssup is similarly calculated from the time and volume of flow through the fluid height reduction from 150 mm test fluid to 130 mm test fluid in the "blank" run. The permeability of the sample support 6050 alone is described by the following equation, where-10 m 2 It is recorded in units of.

[0241]

number

[0242]

number

[0243] The transmittance k of each replicate sample specimen is calculated using the following formula, and then 1.01324998 E +12 Multiply by and record to the nearest 0.1 darcy:

[0244]

number

[0245] where k is the arithmetic mean of the test sample transmittance for all three replicate test samples. specimen is calculated and reported as the transmittance in units of 0.1 darcy.

[0246] Acquisition Time and Rewetting Method This method describes how to measure the gush acquisition time, interfacial free fluid volume, and low and high pressure rewet values ​​for absorbent articles loaded with new Artificial Menstrual Fluid (nAMF; preparation is provided elsewhere herein). Following a pretreatment step, a known volume of nAMF is introduced into the absorbent article three times. The time required for the absorbent article to acquire each dose of nAMF is measured using a see-through plate and an electronic interval timer. After each liquid dose, the interfacial free fluid (IFF) is measured gravimetrically as the fluid transfers from the bottom of the see-through plate to the filter paper. The low and high pressure rewet is then measured after the last liquid dose. The surface free fluid (SFF) is the amount of fluid remaining in the topsheet of the absorbent article. The SFF is measured by performing a rewet at low pressure (0.1 psi). Immediately after measuring the SFF, a higher pressure (0.5 psi) rewet is performed to determine the overall rewet of the absorbent article. All tests are performed in a room maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0247] 15-17B, the see-through plate 9001 is constructed from Plexiglas, or equivalent, having overall dimensions of 10.2 cm long by 10.2 cm wide by 3.1 cm high. A central test fluid well 9008 has a circular opening of 25 mm diameter and is located on the top surface of the plate, with an initial sidewall extending at a 90° angle to a depth of 15 mm, then sloping downward at an 82° angle for an additional depth of 7.5 mm to reach a test fluid reservoir 9003. The test fluid reservoir 9003 is concentric with the test fluid well 9008, has a diameter of 6.6 mm, and has sidewalls extending at a 90° angle to a depth of 5 mm. The test fluid reservoir 9003 opens into a longitudinal fluid channel 9007 located at the bottom of the plate. The longitudinal fluid channel 9007 has side walls that initially extend to a depth of 3.5 mm at the midpoint of the channel (directly below the test fluid reservoir 9003) and then slope downward at an angle 9007a of 0.72° towards each longitudinal end of the channel to a final depth of 3 mm. The longitudinal fluid channel opens to the bottom surface of the plate so that fluid may be introduced onto the underlying test sample. The longitudinal fluid channel 9007 is centered over the test fluid reservoir 9003 and extends in a direction perpendicular to the electrodes 9004. The longitudinal fluid channel 9007 has a width of 5 mm and a length of 80 mm, with lateral edges rounded with a radius 9007b of 1.0 mm. The longitudinal ends of the longitudinal fluid channel 9007 are rounded with a radius 9009 of 2.5 mm. Two wells 9002 (80.5 mm long x 24.5 mm wide x 25 mm deep) located on the outside of the fluid reservoir are filled with stainless steel shot (or equivalent) to adjust the total mass of the plate to provide 0.10 psi (7.0 g / cm) pressure in the test area. 2) of confining pressure. The procedure for determining the test region is described later in this specification. Electrodes 9004 are embedded in the plate 9001 and connect an external banana jack 9006 to the inner wall 9005 of the longitudinal fluid channel 9003. A circuit interval timer is plugged into the jack 9006 and monitors the impedance between the two electrodes 9004 and measures the time from the introduction of the AMF into the reservoir 9003 until the AMF is expelled from the reservoir. The timer has a resolution of 0.01 seconds.

[0248] A pretreatment plate is used in combination with a pretreatment weight to prime the surface of the test sample with a droplet of nAMF as a means of priming the surface of the test sample prior to the introduction of the entire fluid dose. The pretreatment plate is made of plexiglass or equivalent, is 14 inches (35.6 cm) long by 8 inches (20.3 cm) wide, and is approximately 0.25 inches (6.4 mm) thick. The pretreatment plate has five circular markers, each 5 mm in diameter, spaced 1 cm apart (center to center) and positioned along the longitudinal axis of the plate. The center marker is centered at the lateral midpoint of the plate. These markers indicate the placement of the nAMF droplets. The markers are located on the underside of the pretreatment plate and can be milled or simply drawn with a permanent marker or equivalent. The pretreatment weight is 10.2 cm by 10.2 cm and is made of a flat, smooth, rigid material (e.g., stainless steel) with an optional handle. The pre-treatment weight (including the optional handle) has a total mass of 726g + 0.5g and is pressure sensitive to 0.10 psi (7.0 g / cm) across the bottom surface area of ​​the weight. 2 ) pressure.

[0249] When measuring interfacial fluid volume, a rubber pad is used to provide a reproducibly flat surface that allows for uniform pressure distribution. The IFF rubber pad was constructed from high strength neoprene rubber (available from WWGrainger, Inc., part number 1DUV4, or equivalent) with a 40A durometer and 1 / 8 inch thickness and cut to dimensions of 6 inches (15.2 cm) by 6 inches (15.2 cm).

[0250] Apply 0.5 psi (35.1 g / cm) to the test area for the entire rewet portion of the test. 2 A padded weight assembly is required to apply the test area. The procedure for determining the test area is described later in this specification. The rewet weight is constructed as follows: A piece of polyethylene film (approximately 25 microns, any convenient source) is laid horizontally and flat on a rigid bench surface. A piece of polyurethane foam (25 mm thick, 1.0 lb / ft density) is placed on the surface of the test area. 3 A piece of Plexiglas (10.2 cm x 10.2 cm, and approximately 6.4 mm thick) is then stacked on top of the polyurethane foam. Polyethylene film is then used to wrap the polyurethane foam and the Plexiglas plate, which is secured in place with clear tape. The total mass of the padded weight assembly is adjusted to a pressure of 0.5 psi (35.1 g / cm) on the test area. 2 A metal weight with a handle is stacked on top of the plexiglass plate and secured in place so that it can be adjusted to apply a pressure of 100 psi (0.01 mm).

[0251] Various filter paper layers are required for the IFF, SFF and overall rewet process. Prior to testing, the filter paper is conditioned for at least 2 hours at 23°C ± 2°C and 50% ± 2% relative humidity. A suitable filter paper has a basis weight of about 88 gsm, a thickness of about 249 microns, an absorption rate of about 5 seconds, and is available from Ahlstrom-Munksjo (Mt. Holly Springs, PA) as grade 632 or equivalent. The filter paper has dimensions of 5 inches by 5 inches (12.7 cm by 12.7 cm).

[0252] Prior to testing, the test samples are conditioned for at least 2 hours at 23±2°C and 50%±2% relative humidity. Remove the test samples from their outer packaging and, if necessary, open the packaging and unfold the product, taking care not to press down or pull on the product during handling. No attempt is made to smooth out wrinkles. If applicable, tear the release paper between the wings and place the sample horizontally, body side up (e.g., panty side down), on a flat, rigid surface. Determine the dosing location as follows: For symmetrical products (i.e., the front side of the product, when divided transversely along the midpoint of the product's longitudinal axis, is the same shape and size as the rear side of the product), the dosing location is the intersection of the midpoint of the longitudinal axis and the midpoint of the lateral axis of the absorbent core. For symmetrical products (i.e., the front side of the sample, when divided transversely along the midpoint of the product's longitudinal axis, is the same shape and size as the rear side of the product), the dosing location is the midpoint of the product wings at the midpoint of the lateral axis of the absorbent core. For products with a foam core with punched or printed holes and slits, the dosing location is the longitudinal midpoint of the hole punched (or hole printed) area at the lateral midpoint of the absorbent core. Once determined, use a black, fine tip permanent marker to mark the dose location with a small dot. If wings are present, fold the wings onto the back of the product.

[0253] The test area of ​​the test sample is determined as follows: This area is used so that the mass of the strike through plate and the mass of the rewet weight can be appropriately adjusted to deliver the required pressure (0.1 psi and 0.5 psi, respectively). The width of the absorbent core of the test sample is measured along a line placed in the dosing position and extending perpendicular to the longitudinal axis of the test sample as the distance between one side edge of the core and the other side edge of the core, and recorded to the nearest 0.01 cm as the core width. The core width is then multiplied by 10.2 cm (the length of the strike through plate and the rewet weight) to get the 0.1 cm. 2 The total mass of the stain-through plate is 7 g / cm2 of test area. 2 The total mass of the rewet weight is 35.1 g / cm2 of the test area. 2It is multiplied by.

[0254] Test samples are pretreated with nAMF as follows: Place the pretreatment plate horizontally on a flat rigid surface with the side having the circular markers facing down. Using a single channel fixed volume pipettor, dispense 50 μL of nAMF precisely onto the top side of the pretreatment plate at each of the five circular markers. Place the test sample on the pretreatment plate such that the body side of the sample faces the plate, the longitudinal axes of the sample and plate are aligned, and the pre-marked dose location on the test sample is centered over the central drop of the nAMF on the pretreatment plate. Once properly positioned, place the test sample in contact with the pretreatment plate and then immediately apply a pretreatment weight to the backside of the test sample, centered over the dose location / central drop of the nAMF on the pretreatment plate. Start a 40 second timer. After the 40 seconds have elapsed, remove the pretreatment weight from the test sample and remove the test sample from the pretreatment plate. Flip the test sample over so that the body side is facing up and place it horizontally on a flat, rigid surface and proceed quickly to the next step.

[0255] The first capture time (ACQ-1) is measured as follows: Connect an electronic interval timer to the see-through plate 9001 and zero the timer. Position the see-through plate 9001 over the body side of the test sample such that the long axis of the longitudinal fluid channel 9007 on the underside of the see-through plate 9001 is aligned with the longitudinal axis of the test sample, ensuring that the fluid reservoir 9003 is centered over the pre-marked dosing location on the test sample. Note that the nAMF should be visible through the fluid reservoir 9003 at the dosing location on the test sample. Once properly positioned, gently place the see-through plate 9001 over the test sample. Using an adjustable volume pipetter, precisely dispense 2.0 mL of nAMF into the fluid well 9008 of the see-through plate 9001. Fluid is dispensed without splashing along the sloping wall of the fluid well 9008 within a period of 3 seconds or less. Immediately after capturing the fluid, record the first capture time (ACQ-1) displayed on the circuit interval timer to the nearest 0.1 second. Leave the strikethrough plate 9001 in place over the test sample and immediately start the 2 minute timer.

[0256] After the two minutes have elapsed, measure the first interfacial free fluid (IFF-1) as follows: Place the IFF rubber pad horizontally on a flat, rigid surface. Measure the mass of one layer of filter paper to the nearest 0.0001 g and calculate the IFF-1. initial The filter paper is centered on the IFF rubber pad. The strike-through plate 9001 is transferred from the test sample to the pre-weighed filter paper so that the plate is centered on the filter paper and the 8-minute timer is immediately started. After 10 seconds have elapsed on the 8-minute timer, the strike-through plate is removed from the filter paper and gently placed back onto the test sample in the exact same position as before. Within the next 10 seconds, the mass of the filter paper is measured to the nearest 0.0001 g and recorded as IFF-1 final Record as.

[0257] The second capture time (ACQ-2) is measured as follows: After 8 minutes have elapsed, a second spurt of fluid is applied using an adjustable volumetric pipettor to precisely dispense 4.0 mL of nAMF into fluid well 9008 in see-through plate 9001, as described above. Immediately after capturing the fluid, the second capture time (ACQ-2) displayed on the circuit interval timer is recorded to the nearest 0.1 second. Leave see-through plate 9001 in place over the test sample and immediately start the 2 minute timer.

[0258] After the two minutes have elapsed, the second interfacial free fluid (IFF-2) is measured as follows: Place the IFF rubber pad horizontally on a flat, rigid surface. Measure the mass of a new single layer of filter paper to the nearest 0.0001 g and calculate the IFF-2. initial The filter paper is centered on the IFF rubber pad. The Stroke-Through Plate 9001 is transferred from the test sample to the pre-weighed filter paper so that the plate is centered on the filter paper and the 8-minute timer is immediately started. After 10 seconds have elapsed on the 8-minute timer, the Stroke-Through Plate 9001 is removed from the filter paper and gently placed back on the test sample in the exact same position as before. Within the next 10 seconds, the mass of the filter paper is measured to the nearest 0.0001 g and recorded as IFF-2. final Record as.

[0259] The third capture time (ACQ-3) is measured as follows: After 8 minutes have elapsed, a third spurt of fluid is applied using an adjustable volumetric pipettor to precisely dispense 2.0 mL of nAMF into fluid well 9008 in see-through plate 9001, as described above. Immediately after capturing the fluid, the third capture time (ACQ-3) displayed on the circuit interval timer is recorded to the nearest 0.1 second. Leave see-through plate 9001 in place over the test sample and immediately start the 2 minute timer.

[0260] After the two minutes have elapsed, measure the third interfacial free fluid (IFF-3) as follows: Place the IFF rubber pad horizontally on a flat, rigid surface. Measure the mass of a new single layer of filter paper to the nearest 0.0001 g and measure the IFF-3. initialRecord as . The filter paper is centered on the IFF rubber pad. Transfer the Stroke-Through Plate 9001 from the test sample to the pre-weighed filter paper so that the plate is centered on the filter paper and immediately start the 8-minute timer. After 10 seconds on the 8-minute timer, remove the Stroke-Through Plate 9001 from the filter paper and set it aside so that the pad side of the plate does not touch the bench. Within the next 10 seconds, measure the mass of the filter paper to the nearest 0.0001 g and record the IFF-3 final Record as.

[0261] Measure the surface free fluid (SFF) as follows: After 8 minutes have elapsed, measure the mass of a new stack of 5 filter papers to the nearest 0.0001 g and calculate the SFF initial The stack of filter papers is placed on top of the body side of the test sample such that they are centered over the top of the dosing location. Now, gently place the Smear-Through Plate 9001 on top of the filter papers so that the pad side of the plate is centered over the filter paper and immediately start a 10 second timer. After the 10 seconds have elapsed, remove the Smear-Through Plate 9001 from the filter papers and set aside. Measure the mass of the stack of five filter papers to the nearest 0.0001 g and record the SFF. final Record this as . Proceed immediately to the next step.

[0262] The total rewet is measured as follows: measure the mass of a new stack of 5 filter papers to the nearest 0.0001 g and initial The filter paper is placed on the body side of the test sample so that it is centered over the top of the dosing location. The padded rewet weight is then placed on top of the filter paper stack so that the weight is centered over the filter paper stack and a 30 second timer is immediately started. After the 30 seconds have elapsed, the rewet weight is removed and the mass of the five filter paper stacks is measured to the nearest 0.0001 g, then the REWET final After discarding the sample and washing thoroughly, the fluid wells 9008, fluid reservoirs 9003, longitudinal fluid channels 9007, and the bottom surface of the see-through plate 9001 are allowed to dry before the next sample is tested.

[0263] The following calculations are made for each of the parameters measured as follows: Total blast absorption time is calculated as the sum of ACQ-1, ACQ-2 and ACQ-3 and recorded to the nearest 0.1 second. IFF-1 final From IFF-1 initial Calculate IFF-1 by subtracting IFF-2 from IFF-3 and record to the nearest 0.0001 g. final From IFF-2 initial Calculate IFF-2 by subtracting IFF-3 from IFF-4 and record to the nearest 0.0001 g. final From IFF-3 initial Calculate IFF-3 by subtracting IFF-1, IFF-2, and IFF-3 and record to the nearest 0.0001 g. Calculate total IFF as the sum of IFF-1, IFF-2, and IFF-3 and record to the nearest 0.1 g. SFF final From SFF initial Calculate SFF by subtracting and record to the nearest 0.0001 g. Calculate Total IFF+SFF as the sum of Total IFF and SFF and record to the nearest 0.1 g. REWET final From REWET initial Calculate total rewet by subtracting and record to the nearest 0.0001 g.

[0264] The entire procedure is repeated for a total of three replicate test samples. The reported values ​​for each parameter are the arithmetic average of three individually recorded measurements for each acquisition time (ACQ-1, ACQ-2, and ACQ-3) to the nearest 0.1 seconds, total gush absorption time to the nearest 0.1 grams, interfacial free fluid (IFF-1, IFF-2, and IFF-3) to the nearest 0.0001 grams, total IFF to the nearest 0.1 grams, surface free fluid (SFF) to the nearest 0.0001 grams, total IFF+SFF to the nearest 0.1 grams, and total rewet to the nearest 0.0001 grams.

[0265] Preparation of fresh artificial menstrual fluid (nAMF) This formulation of artificial menstrual fluid (nAMF) is composed of a mixture of defibrinated sheep blood, phosphate buffered saline, and mucus components. nAMF is prepared to have a viscosity of 7.40-9.00 centipoise at 23 °C.

[0266] The viscosity of the nAMF is performed using a low viscosity rotational viscometer (a suitable instrument is a Brookfield DV2T with a Brookfield UL adapter, or equivalent, available from AMETEK Brookfield, Middleboro, MA). The appropriate size spindle for the viscosity range is selected and the instrument is operated and calibrated according to the manufacturer. Measurements are taken at 23° C.±1° C. and 60 rpm. Results are reported to the nearest 0.01 centipoise.

[0267] Reagents required for nAMF preparation include defibrinated sheep blood with a packed cell volume of 38% or greater (drawn under sterile conditions, available from Cleveland Scientific, Inc., Bath, OH, or equivalent source), gastric mucin (crude form, sterile, available from American Laboratories, Inc., Omaha, NE, or equivalent source) with a target viscosity of 3-4 centistokes when prepared as a 2% aqueous solution, sodium phosphate dibasic anhydrous (reagent grade), sodium chloride (reagent grade), sodium phosphate monobasic monohydrate (reagent grade), sodium benzoate (reagent grade), benzyl alcohol (reagent grade), and distilled water (each available from VWR International or equivalent source).

[0268] Phosphate buffered saline consists of two individually prepared solutions (Solution A and Solution B). To prepare 1 L of solution A, add 1.38 ± 0.005 g of sodium phosphate monobasic monohydrate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to the volume of the vessel. Mix thoroughly. To prepare 1 L of solution B, add 1.42 ± 0.005 g of sodium phosphate dibasic anhydrous and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to the volume of the vessel. Mix thoroughly. To prepare approximately 200 mL of phosphate buffered saline solution, add 49.50 g ± 0.10 g of solution A and 157.50 g + 0.10 g of solution B to a bottle of sufficient size with a tight-fitting lid. Then 1.0 g of sodium benzoate and 1.60 g of benzyl alcohol are added to the bottle along with a stir bar and set aside.

[0269] The mucus component of nAMF is a mixture of phosphate buffered saline and gastric mucin. The amount of gastric mucin added to the mucus component directly affects the final viscosity of the prepared nAMF. To determine the amount of gastric mucin required to obtain nAMF within the target viscosity range (7.4-9.0 centipoise at 23°C and 60 rpm), three batches of nAMF with various amounts of gastric mucin in the mucus component are prepared, then a least squares linear fit through the three points is performed and the exact amount required is interpolated from the concentration vs. viscosity curve. The appropriate range of gastric mucin is usually 13-15 grams per 400 mL batch of nAMF, but this can vary widely based on the source, age, and lot of mucin.

[0270] To prepare approximately 200 mL of mucus component, a predetermined amount of gastric mucin is added to the bottle containing the previously prepared phosphate buffered solution and then capped. The bottle is placed on a wrist action shaker at maximum speed for 5 minutes. After 5 minutes, the flask with the mucus component is removed from the wrist action shaker and placed on a magnetic stir plate. Stir for at least 2 hours until no clumps of mucin are present, then remove the stir bar from the flask. The mucus component is mixed using a homogenizer at 10,000 rpm for 5 minutes. A suitable homogenizer is a T18 Ultra-Turrax with an S18N-19G dispersion tool (19 mm stator diameter, 12.7 mm rotor diameter, 0.4 mm gap between rotor and stator), both available from IKA Works, Inc, Wilmington, NC or equivalent source. After the final mixing step, measure and record the viscosity of the mucus component to the nearest 0.01 centipoise using a viscometer equipped with a UL adapter at 23 °C ± 1 °C and 20 rpm. Ensure that the viscosity of the prepared mucus component is within the target range of 9.0 - 11.0 centipoise.

[0271] nAMF is a 50:50 mixture of mucus component and sheep blood. Ensure that the temperature of the sheep blood and mucus component is 23°C ± 1°C. To prepare approximately 400 mL of nAMF, add 200 g of mucus component to a glass bottle of at least 500 mL capacity. Then, add 200 g of sheep blood to the bottle along with a stir bar. Mix on a magnetic stir plate until completely mixed. Ensure that the viscosity of the prepared nAMF is within the target range of 7.4 to 9.0 centipoise when measured at 23°C ± 1°C and 60 rpm using a viscometer with a UL adapter. If the viscosity is too high, the viscosity can be adjusted by adding 0.5 g of the previously prepared phosphate buffered saline solution in increments, followed by stirring for 2 minutes, and then rechecking the viscosity until it reaches the target range.

[0272] Certified nAMF must be refrigerated at 4°C unless intended for immediate use. After preparation, nAMF may be stored in an airtight container at 4°C for up to 48 hours. Prior to testing, nAMF must be kept at 23°C ± 1°C. After testing is completed, any unused portion is discarded.

[0273] Examples / Data The following data and examples, including comparative examples, are provided to aid in the description of the upper and lower nonwoven layers, absorbent core structures, and / or absorbent articles described herein. The illustrated structures are provided for illustrative purposes only and should not be construed as limiting the invention, as many variations thereof are possible without departing from the spirit and scope of the present disclosure.

[0274] Nonwoven Material Testing The nonwoven layer materials are tested to evaluate the ability of the nonwoven material to undergo strain (stretch) in balanced extension and recover to its original state (simulating physical deformation during use). Samples F-H are comparative examples. Samples A-H and I are tested at different times, however, the data are presented together for ease of comparison. Testing is performed according to the CD cyclic extension method to 3% strain and the strain to break method described herein. The results are shown in Table 1.

[0275] [Table 1] 1 Available as ATB Z87G-40 from Xiamen Yanjan New Material Co. (China) 2 Available from Sandler GmbH, Germany as Sawasoft® 53FC041001 3 Available from Sandler GmbH, Germany as Sawasoft® 553FC041005 (option 82) 4Available as Aura 20 from Xiamen Yanjan New Material Co. (China) 5 Available from Jacob Holms Industries, Germany as S25000541R01 6 Available from dPFNonwovens Czech SRO (Czech Republic) as PFNZN 18G BICO8020 PHI 6 7 Available from dPFNonwovens Czech SRO (Czech Republic) as PEGZN25 BICO7030 Phobic 8 Available from DunnPaper (USA) as 3028 9 Available from Union Industries SpA. (Italy) as 10 SMS PHILIC

[0276] Suitable nonwoven layer materials have been found to distort (stretch) with a balanced stretch-to-recovery behavior. If the nonwoven layer material stretches plastically (i.e., stretches but does not recover) as the fluff / AGM matrix in the inner core layer stretches, there will be insufficient recovery energy to return to the initial pre-stretch state, and the nonwoven layer material will become permanently distorted (stretched). The upper nonwoven layer of the present disclosure may have a permanent set value of less than about 0.013. At the same time, when the nonwoven layer material is actively distorted, for example, by more than 5%, the nonwoven layer material should retain its integrity and not break or rupture (see, for example, sample H, which breaks and has a breaking strain of less than 5%). The nonwoven layer of the present disclosure may have a breaking strain of greater than about 10%.

[0277] A subset of the nonwoven layer materials described above are also tested to evaluate the ability of the nonwoven materials to bend, deform, and recover to their original state. The testing is performed according to the wet and dry CD ultrasensitive three-point bending method described herein. The results are shown in Table 2.

[0278] [Table 2]

[0279] During walking, the absorbent article is compressed and flexed from side to side in a cyclical pattern as the gap between the wearer's legs narrows and then expands with the movement of the wearer's legs. Without being limited by theory, it is believed that the absorbent article is compressed and flexed from side to side in a cyclical pattern as the gap between the wearer's legs narrows and then expands with the movement of the wearer's legs. * A nonwoven layer material having a dry bending energy of less than 0.03 N would readily allow this bending compression to occur, but would not be so stiff as to prevent bending compression. At the same time, following bending compression, the nonwoven layer must be able to maintain sufficient dry recovery energy to return the fluff / AGM matrix in the nonwoven layer and inner core layer to their initial pre-bending state. The upper nonwoven layer of the present disclosure has a dry bending energy of about 0.03 N. * The dry recovery energy value may be greater than 1.5 mm.

[0280] Samples A to E have dry peak loads of 0.03N to 0.38N and 0.032 to 0.092N. * The comparative samples, Samples F and G, exhibited dry peak loads of 0.01 N and 0.03 N, respectively, and dry recovery energies of 0.005 N, respectively, demonstrating that these materials bend easily and have sufficient dry recovery energies to recover to their initial unbended state. * mm and 0.019N * Sample H (comparative) exhibited a dry peak load of 0.04 N and a dry recovery energy of 0.031 N, demonstrating that these materials bend easily but do not have sufficient recovery energy to recover to their initial unbended state after compression. * 1.5 mm Dry Recovery Energy However, Sample H is found to tear when wet, rendering it insufficient to function as an upper and / or lower nonwoven layer of the present disclosure.

[0281] Without being limited by theory, it is believed that nonwoven layer materials comprising thick fibers (about 2.0 Dtex to about 10 Dtex) arranged in a network structure are able to carry mechanical loads within the fiber network and allow the absorbent core structure and / or absorbent article to return to its original shape after bending and compression. Samples F and G comprise relatively fine fibers (less than about 2.0 Dtex), while Samples A-E comprise fiber blends having fiber sizes from about 2.2 Dtex to about 10 Dtex.

[0282] Absorbent Core Structure Testing The absorbent core structures are tested to evaluate their ability to compress (simulating compression experienced between the legs of a wearer) and recover to their original state. Examples 1-3 illustrate absorbent core structures as described herein. Comparative Examples A-C are comparative examples. Descriptions of Examples 1-3 and Comparative Examples A-C are provided in Table 3. The absorbent core structures are prepared as described hereinafter. The absorbent core structures are evaluated according to the wet and dry bunch compression methods described herein. Results are provided in Table 4.

[0283] [Table 3] 1 Available as ATB Z87G-40 from Xiamen Yanjan New Material Co. (China) 3 Available from Sandler GmbH, Germany as Sawasoft® 553FC041005 (option 82) 4 Available as Aura 20 from Xiamen Yanjan New Material Co. (China) 5 Available from Jacob Holms Industries, Germany as S25000541R01 6 Available from dPFNonwovens Czech SRO (Czech Republic) as PFNZN 18G BICO8020 PHI 6 8 Available from DunnPaper (USA) as 3028 10 Available from Evonik (Germany) as Favor SXM9745 11 Available from Resolute Alabama (USA) as part number 9E 3-COOSABSORBS 12 Available from Fitesa (Germany) as article 4004416 (MR 3585374)

[0284] The absorbent core structures listed in Table 3 are produced as detailed herein. Specifically, the upper nonwoven layer is first introduced onto a forming drum in the laydown section and stretched under vacuum into a three-dimensional pocket shape. A homogeneous flow of fluff (cellulose) and AGM materials is deposited directly onto the upper nonwoven layer in the forming station. Before entering the forming station, the upper nonwoven is coated with a spray adhesive (Technomelt DM 9036U, 6 gsm continuous meltblown spiral, 50 mm wide, available from Henkel, Germany) to provide a stronger connection of the fluff (cellulose) and AGM to the upper nonwoven layer without impeding the flow of liquid into the fluff / AGM matrix. Upon exiting the laydown section, the lower nonwoven web is combined with the nonwoven carrying the homogeneous blend of fluff / AGM. This bottom nonwoven is pre-coated with adhesive (Technomelt DM 9036U available from Henkel, Germany) to allow a perimeter seal (10 gsm meltblown spiral, 20 mm wide on the sides) and in the center a 6 gsm, 50 mm wide continuous meltblown spiral adhesive is applied to better integrate the fluff / AGM matrix.

[0285] Examples 1-3 and Comparative Examples A and B also have the structural bonds shown in FIG. 4 with the profile shown in FIG. 5. Examples 1-3 and Comparative Examples A and B have a structural bond spacing of 32 mm×16 mm, thereby accounting for a total structural bond site area of ​​1.38% of the total area of ​​the absorbent core structure. Comparative Example C is identical to Comparative Example B, except that the structural bond spacing is 10 mm×10 mm, thereby accounting for a total structural bond site area of ​​6.28% of the total area of ​​the absorbent core structure. The structural bonds are applied using a heated aluminum die to form an embossed pattern in a heated hydraulic press. The structural bond embossing plate is 3.55 mm wide, as shown in FIG. 4. 2 and protrusions of about 1 mm height, with the profile shown in FIG. 5. The structural bonds are spaced according to the separation dimensions above. The structural bond embossing plate is heated to 120° C. and set to a compression pressure of 170 kPa. The absorbent article is placed and oriented under the heated embossing plate on the bottom plate of the hydraulic press, and a sheet of thin Teflon™ film is placed over the sample prior to embossing to avoid melting the topsheet fibers. The hydraulic press is turned on and the sample is compressed for a dwell time of 1.7 seconds to create the structural bond pattern.

[0286] Examples 1-3 and Comparative Examples A-C also have flexible bond channel regions applied with the pattern shown in FIG. 2C. The flexible bond channel regions are applied using a heated aluminum die to create an embossed pattern in a heated hydraulic press. The flexible bond channel embossing plate is about 3 mm long and about 1.5 mm wide with protrusions spaced about 1.5 mm apart. The bond channel embossing plate is heated to 120° C. and set to a compression pressure of 200 kPa. The absorbent article is placed and oriented under the heated embossing plate on the hydraulic press bottom plate, and a sheet of thin Teflon™ film is placed over the sample prior to embossing to avoid melting the topsheet fibers. The hydraulic press is activated and the sample is compressed for a dwell time of 1.7 seconds to create the embossed pattern.

[0287] [Table 4]

[0288] It has been found that absorbent core structures comprising nonwoven layer materials with sufficient elasticity and recovery energy can recover to the original pre-compression absorbent core structure shape. * 5th cycle wet recovery energies of over 0.26 to 0.59 N, and 5th cycle wet maximum compression forces of 207 to 213 gf. Although these structures exhibit low compression forces (feeling softer and more flexible because they exhibit lower resistance), they are still able to recover their shape as the structures are cyclically compressed and released. However, Comparative Examples A to C exhibit wet maximum compression forces of 0.26 to 0.59 N. * Figure 1 shows the 5th cycle wet recovery energy in mm. Without sufficient recovery energy after 5 cycles of compression, Comparative Examples A-C remain in a compressed clump with insufficient force (stored energy) to recover their original pre-compressed shape.

[0289] The absorbent core structure and / or absorbent article of the present disclosure may have a resistance of about 1.0 N * mm or about 1.0 to about 3.5 N * The absorbent core structure and / or absorbent article of the present disclosure may have a 5th cycle wet maximum compression of greater than about 150 gf, preferably greater than about 200 gf, or from about 150 gf to about 225 gf.

[0290] It has been found that while an individual nonwoven material may have a sufficient breaking strain % in the breaking strain method, when incorporated into an absorbent core structure, the nonwoven material may not provide enough recovery energy (e.g., in Comparative Example A) for the entire absorbent core structure to return to its original pre-compressed shape. For example, in Comparative Example A, the fiber basis weight and caliper of the upper nonwoven material when combined with a thinner lower nonwoven material is 1.0 N * Provides a 5th cycle wet recovery energy of less than mm.

[0291] Final Product Testing The absorbent articles are tested to evaluate the ability of the wrapped absorbent core structure to compress (simulating compression experienced between the legs of a wearer) and recover to its original state. Examples 4-7 show absorbent articles as described herein. Comparative Examples D and E are comparative examples. Comparative Examples F-L are commercial end products. Examples 4-7 and Comparative Examples D-E are listed in Table 5a. Comparative Example FL is listed in Tables 5b and 5c. Examples 4-7 and Comparative Examples D and E are prepared as described below. The examples in Tables 5a and 5b are evaluated according to the wet and dry CD and MD 3-point bend method, the wet and dry bunching method, and the light touch rewet method as described herein. The results are shown in Table 6.

[0292] [Table 5] 1 Available as ATB Z87G-40 from Xiamen Yanjan New Material Co. (China) 2 Available from Sandler GmbH, Germany as Sawasoft® 53FC041001 3 Available from Sandler GmbH, Germany as Sawasoft® 553FC041005 (option 82) 4 Available as Aura 20 from Xiamen Yanjan New Material Co. (China) 5 Available from Jacob Holms Industries, Germany as S25000541R01 6 Available from dPFNonwovens Czech SRO (Czech Republic) as PFNZN 18G BICO8020 PHI 6 8 Available from DunnPaper (USA) as 3028 10 Available from Evonik (Germany) as Favor SXM9745 11 Available from Resolute Alabama (USA) as part number 9E3-COOSABSORB S 13 The nonwoven topsheet "Nonwoven SG" is a nonwoven web according to U.S. Patent Application Publication No. 2019 / 0380887.

[0293] [Table 6]

[0294] [Table 7]

[0295] Examples 4-7 and Comparative Examples D and E also include the structures detailed for Examples 1-3 in Table 3, with the same adhesive design and the same 32 mm x 16 mm structural bond pattern in the example absorbent core structures (total structural bond site area of ​​1.38% of the total area of ​​the absorbent core structure). In addition, the absorbent articles include a nonwoven topsheet web as detailed in U.S. Patent Application Publication No. 2019 / 0380887, bonded to the absorbent core structures by application of a spray adhesive (Technomelt DM 9036U, 3 gsm continuous meltblown spiral, 50 mm wide, 150 mm long, available from Henkel, Germany). In addition, a 12 gsm polypropylene backsheet is bonded to the outer facing surface of the lower nonwoven using a spray adhesive (Technomelt DM 9036U, 3 gsm continuous meltblown spiral, 50 mm wide, 150 mm long, available from Henkel, Germany).

[0296] Examples 4-7 and Comparative Examples D and E also have the structural bond shown in FIG. 4 with the profile shown in FIG. 5. The structural bond is applied using a heated aluminum die to form an embossed pattern in a heated hydraulic press. The structural bond embossing plate is 3.55 mm thick as shown in FIG. 2 and approximately 1 mm high projections, with the profile shown in FIG. 5. The structural bonds are spaced according to the separation dimensions above. The structural bond embossing plate is heated to 120° C. and set to a compression pressure of 170 kPa. The absorbent article is placed and oriented under the heated embossing plate on the hydraulic press bottom plate, and a sheet of thin Teflon™ film is placed over the sample prior to embossing to avoid melting the topsheet fibers. The hydraulic press is turned on and the sample is compressed for a dwell time of 1.7 seconds to create the structural bond pattern.

[0297] Prior to bonding the backsheet, a flexible bond channel area is applied to Examples 4-7 and Comparative Examples D and E with the pattern shown in FIG. 2C. The flex bond channel area is applied using a heated aluminum die to create an embossed pattern in a heated hydraulic press. The flexible bond channel embossing plate is about 3 mm long and about 1.5 mm wide with protrusions spaced about 1.5 mm apart. The bond channel embossing plate is heated to 120° C. and set to a compression pressure of 200 kPa. The absorbent article is placed and oriented under the heated embossing plate on the hydraulic press bottom plate, and a sheet of thin Teflon™ film is placed over the sample prior to embossing to avoid melting the topsheet fibers. The hydraulic press is activated and the sample is compressed for a dwell time of 1.7 seconds to create the embossed pattern.

[0298] [Table 8]

[0299] In order to provide high body conformity, the absorbent article of the present disclosure has a compressive strength of about 10 to about 30 N.mm2 , or about 10 to about 25 N.mm 2 It is believed that the absorbent articles of the present disclosure may exhibit a low CD dry bending stiffness (i.e., high flexibility) of from about 1.0 to about 3.5 N.mm and / or a 5th cycle wetness recovery % of from about 29% to about 40% to provide an absorbent article that can compress with body movement and recover to its original pre-compressed state against the user's body. The absorbent articles of the present disclosure may also maintain good fluid handling resulting in low light touch rewet of from about 0 to about 0.15 g.

[0300] In Examples 4 to 7, the values ​​are 13.0 to 18.7 N.mm 2 and 5th cycle wet recovery % in wet and dry bunch compression method of 29-36%, demonstrating that these structures can maintain their shape during use. Comparative Examples D and E exhibited CD dry bending stiffness of 9.1 and 13.0 N.mm, respectively. 2 However, Comparative Examples D and E exhibit 5th cycle wet recovery % in the Wet and Dry Bundle Compression Method that is less than 29%, demonstrating that these structures are unable to maintain their shape and remain bundled during use. Comparative Examples F-L are commercially available finished products and exhibit CD dry bending stiffness ranging from 29 to 47.5 N.mm 2 , demonstrating that the construct is less flexible and less compliant.

[0301] Without being bound by theory, it is believed that in order to maintain a comfortable shape recovery after compression, sufficient recovery energy is required to push the absorbent article on the panty back to its pre-compression shape. At the same time, the absorbent article (through the absorbent core structure) needs to recover along the same path as compression to return to its pre-compression position. If the 5th cycle wet recovery energy is less than about 1.0 N.mm, the absorbent article may not have the necessary recovery energy to recover its shape. If the 5th cycle wet recovery energy value is too high, the recovery may be too strong, causing the wearer to feel that the absorbent article is not staying in place. If the 5th cycle wet recovery % value is low (less than about 29%), the absorbent article may not return to its pre-compression shape and may remain deformed and bunched. It is suggested that if the 5th cycle wet recovery % value is too high (more than about 40%), the absorbent article may recover too strongly to a flat shape when first applied to the wearer's panty, as opposed to its shape against the wearer's body.

[0302] Structural Integration Testing The absorbent core structures are tested to evaluate the effect of structural bond regions on flexibility and bending stiffness. Example 8 does not feature any structural bonds within the absorbent core structure. Examples 9 and 10 have the structural bonds shown in Figure 4 with the profile shown in Figure 5. Examples 8-10 are prepared as described below. Wet and dry MD 3-point bending results are shown in Table 7.

[0303] [Table 9] 3 Available from Sandler GmbH, Germany as Sawasoft® 553FC041005 (option 82) 9 Available from Union Industries SpA. (Italy) as 10 SMS PHILIC 10 Available from Evonik (Germany) as Favor SXM9745 11 Available from Resolute Alabama (USA) as part number 9E3-COOSABSORB S

[0304] Table 7 shows the effect of total structural bond site area and spacing. The asymmetric structural bond shape shown in FIG. 4 and the profile shown in FIG. 5 are 3.55 mm 2 The MD dry bending stiffness is found to increase with structural bond area. Example 8 has a non-structural bond and has a maximum area of ​​9.8 N.mm 2 Example 9 has a structural bond spacing of 32 mm x 16 mm (total structural bond site area of ​​1.38% of the total absorbent core structure area) and exhibits a MD dry bending stiffness of 19.2 N.mm 2 Example 10 has a structural bond spacing of 16 mm x 16 mm (total structural bond site area of ​​3.96% of the total absorbent core structure area) and exhibits a MD dry bending stiffness of 29.6 N.mm 2 In order to maintain a soft and conforming absorbent core structure and / or absorbent article in the front-to-back (MD) direction of wear, the absorbent core structure and / or absorbent article should exhibit a MD dry bending stiffness of about 10 to about 30 N.mm 2 It is considered that the MD dry bending stiffness can be

[0305] The absorbent core structures listed in Table 7 are produced as detailed herein. Specifically, a 50 gsm elastic spunlace 6 upper nonwoven is first introduced onto a forming drum in the laydown section and stretched under vacuum into a three-dimensional pocket shape. A homogeneous flow of fluff (cellulose) and AGM material is deposited directly onto the upper nonwoven material in the forming station. Before entering the forming station, the upper nonwoven is coated with a spray adhesive (Technomelt DM 9036U, 6 gsm continuous meltblown spiral, 50 mm wide, available from Henkel, Germany) to provide a stronger connection of the fluff (cellulose) and AGM to the upper nonwoven layer without impeding the flow of liquid into the fluff / AGM mass. Upon exiting the laydown section, a 10 gsm SMS lower nonwoven web is combined with the nonwoven carrying a homogeneous blend of the fluff (cellulose) and AGM layers. The bottom nonwoven is pre-coated with adhesive (Technomelt DM 9036U available from Henkel, Germany) to allow for perimeter sealing (10 gsm meltblown spiral, 20 mm wide at the sides) and in the center, a 6 gsm, 50 mm wide continuous meltblown spiral adhesive is applied to better integrate the fluff / AGM mass. Structural bonds as shown in FIG. 4 with the profile shown in FIG. 5 are applied to Examples 9 and 10. The structural bonds of Example 9 have a spacing of 32 mm×16 mm, thereby occupying a total structural bond site area of ​​1.38% of the total area of ​​the absorbent core structure. The structural bonds of Example 10 have a spacing of 16 mm×16 mm, thereby occupying a total structural bond site area of ​​3.96% of the total area of ​​the absorbent core structure with this structural bond profile. The total area of ​​the absorbent core structure is measured according to the structural bond site pattern spacing and area measurement method. The structural bonds are applied in the same manner as described above for Examples 1-3 and Comparative Examples A and B.

[0306] Fluid Management Testing Nonwoven materials are tested to evaluate the material's ability to effectively manage fluids. Samples F, H, and I are comparative examples. Sample descriptions are listed in Table 1 above. Materials are evaluated according to thickness-pressure method, permeability measurement method, pore volume distribution method, and wet penetration time method. Density is determined by dividing the basis weight of the material by the thickness. Results are shown in Table 8.

[0307] [Table 10]

[0308] Samples A, B, C and E are 7g / cm 2 Under pressure of 0.03~0.07g / cm 3 The comparative samples F, H and I exhibited relatively low densities of 0.80 to 1.21 mm at a pressure of 7 g / cm2, demonstrating that these materials have a bulkier, more open fiber network. 2 Under pressure of 0.09 to 0.12 g / cm 3 and a significantly lower caliper of 0.10-0.21 mm at a pressure of 7 g / cm2. Without being bound by theory, it is believed that when a nonwoven material having a low density (i.e., less than 0.09 g / cm3) is used as the upper nonwoven layer of the absorbent core structures disclosed herein, the fluff / AGM matrix of the inner core layer can better wick away fluids from the upper nonwoven layer.

[0309] Samples A, B, C, and E also shrunk under high body compression (70 g / cm 22), demonstrating that these materials can still effectively wick fluid through the fluff / AGM matrix. In contrast, Samples F, H, and I exhibit thicknesses of 0.09-0.17 mm at a pressure of 70 g / cm2, demonstrating that these materials are more densified and therefore exhibit higher capillarity, and are therefore insufficient as upper nonwoven layers because fluid wicking into the fluff / AGM matrix is ​​limited for materials with higher capillarity than the underlying fluff / AGM matrix.

[0310] Finally, Samples F, H, and I were found to have Wet Penetration Times greater than 4 seconds, demonstrating that the fluid does not penetrate straight through the material, but instead spreads over the material. In contrast, Samples A, B, C, and E had Wet Penetration Times less than about 4 seconds, demonstrating that the fluid can more efficiently move through the material and more quickly into the fluff / AGM matrix, versus spreading over the surface as seen in Samples F, H, and I. The upper nonwoven layer of the present disclosure can have a Wet Penetration Time less than about 4 seconds, and preferably less than about 3 seconds.

[0311] Consumers may prefer absorbent articles that can conform to the body and provide a dry wearing experience. In another experiment, absorbent articles are prepared to further evaluate the absorbent article's ability to compress and recover to its original state, and to effectively wick away fluid. Examples 11-14 show absorbent articles as described herein. Comparative Examples M-O are commercial end products. Descriptions of Examples 11-14 and Comparative Examples M-O are listed in Tables 9a and 9b. Examples 11-14 are prepared as described below. Examples 11-14 are tested at different times than Examples 15-17 and Comparative Examples M-O. However, the data are presented together for ease of comparison. Examples 11-14 and Comparative Examples M-O are evaluated according to the wet and dry CD and MD 3-point bend method and the wet and dry clump compression method, with the results shown in Table 10, and according to the acquisition time and rewet method and the light touch rewet method, with the results shown in Table 11.

[0312] [Table 11] 1 Available as ATB Z87G-40 from Xiamen Yanjan New Material Co. (China) 5 Available from Jacob Holms Industries, Germany as S25000541R01 6 Available from dPFNonwovens Czech SRO (Czech Republic) as PFNZN 18G BICO8020 PHI 6 10 Available from Evonik (Germany) as Favor SXM9745 11 Available from Resolute Alabama (USA) as part number 9E3-COOSABSORB S 13 The nonwoven topsheet "Nonwoven SG" is a nonwoven web according to U.S. Patent Application Publication No. 2019 / 0380887. 14 Available as ATB Z73P from Xiamen Yanjan New Material Co. (China) 15 Available as MYRITOL 318 from BASF Corporation (USA). 16 Available as CETIOL E from BASF Corporation (USA).

[0313] [Table 12]

[0314] Examples 11-17 of absorbent articles are manufactured as detailed herein. Specifically, the upper nonwoven layer is first introduced onto a forming drum in the laydown section and stretched under vacuum into a three-dimensional pocket shape. A homogeneous flow of fluff (cellulose) and AGM material is deposited directly onto the upper nonwoven material in the forming station. Before entering the forming station, the upper nonwoven is coated with a spray adhesive (Technomelt DM 9036U, 6 gsm continuous meltblown spiral, 50 mm wide, available from Henkel, Germany) to provide a stronger connection of the fluff (cellulose) and AGM to the upper nonwoven layer without impeding the flow of liquid into the fluff / AGM mass. Upon exiting the laydown section, the lower nonwoven web is combined with the nonwoven carrying a homogeneous blend of the fluff (cellulose) and AGM layers. This bottom nonwoven is pre-coated with adhesive (Technomelt DM 9036U available from Henkel, Germany) to allow a perimeter seal (10 gsm meltblown spiral, 20 mm wide on the sides) and in the center a 6 gsm, 50 mm continuous meltblown spiral adhesive (Technomelt DM 9036U available from Henkel, Germany) is applied to better integrate the fluff / AGM mass. Additionally, the absorbent article is bonded to the absorbent core structure by applying a spray adhesive (Technomelt DM 9036U available from Henkel, Germany, 3 gsm continuous meltblown spiral, 50 mm wide, 150 mm long). In addition, a 12 gsm polypropylene film backsheet is bonded to the bottom (garment facing) surface of the lower nonwoven using the application of a spray adhesive (Technomelt DM 9036U available from Henkel, Germany, 3 gsm continuous meltblown spiral, 50 mm wide, 150 mm long). Examples 11-17 also have the structural bonds shown in FIG. 4 with the profile shown in FIG. 5, applied at 32 mm by 16 mm spacing, thereby occupying a total structural bond site area of ​​1.38% of the total area of ​​the absorbent core structure. The structural bonds are applied using the methods described above for Examples 1-3 and Comparative Examples A-B.Prior to bonding the backsheet, a flexible bond channel is applied to Examples 11-13 with the pattern shown in FIG. 2C. The flexible bond channel is applied using a heated aluminum die to create an embossed pattern in a heated hydraulic press. The flexible bond channel embossing plate is about 3 mm long and about 1.5 mm wide with protrusions spaced about 1.5 mm apart. The bond channel embossing plate is heated to 120° C. and set to a compression pressure of 200 kPa. The absorbent article is placed and oriented under the heated embossing plate on the hydraulic press bottom plate, and a sheet of thin Teflon™ film is placed over the sample prior to embossing to avoid melting the topsheet fibers. The hydraulic press is activated and the sample is compressed for a dwell time of 1.7 seconds to create the embossed pattern.

[0315] [Table 13]

[0316] [Table 14]

[0317] Surprisingly, it has been found that flexible and / or elastic absorbent core structures and / or absorbent articles can effectively manage fluids as they exit the body without the need for typical densification / stiffening. Examples 11-17 have comparable total IFF+SFF and light touch rewet values ​​as Comparative Examples M-O, which have significantly higher CD dry bending stiffness as a result of densification (Table 10).

[0318] Light Touch Rewet in grams (g) is plotted against CD Dry Bending Stiffness in N.mm2 in the graph shown in Figure 18. In some embodiments, the absorbent article has a Light Touch Rewet value of about 0 g to about 0.15 g, as measured according to the Light Touch Rewet Method, and a Light Touch Rewet value of about 10 N.mm2, as measured according to the Wet and Dry CD and MD 3-Point Bend Method. 2 ~Approx. 30N.mm 2and C-D dry bending stiffness.

[0319] The total IFF+SFF in milligrams (mg) is plotted against the CD dry bending stiffness in N.mm2 in the graph shown in Figure 19. In some embodiments, the absorbent article has a stiffness of about 10 N.mm2 as measured according to the wet and dry CD and MD 3-point bending method. 2 ~Approx. 30N.mm 2 and a CD Dry Bending Stiffness of from about 20 mg to about 200 mg, as measured according to the Acquisition Time and Rewet Method.

[0320] Combinations / Examples Paragraph A. A disposable absorbent article comprising: A top sheet; Back seat and an absorbent core structure disposed between a topsheet and a backsheet, (a) an upper nonwoven layer comprising polymeric fibers; (b) a lower nonwoven layer comprising polymeric fibers; and (c) an inner core layer disposed between the upper nonwoven layer and the lower nonwoven layer, the inner core layer comprising about 50% to about 85% by weight of the inner core layer of cellulose fibers and superabsorbent particles; and Including, the inner core layer is contained within the nonwoven layers by substantially sealing at least the left and right regions of the upper and lower nonwoven layers with a perimeter seal; The absorbent article is a disposable absorbent article having a CD dry bending stiffness, measured according to the wet and dry CD and MD 3-point bending method, of about 10 N.mm2 to about 30 N.mm2, and a total IFF+SFF value, measured according to the acquisition time and rewet method, of about 20 mg to about 200 mg.

[0321] Paragraph B. A disposable absorbent article according to Paragraph A, wherein the absorbent article has a 5th cycle % Wet Recovery of from about 29% to about 40% as measured according to the Wet and Dry Bundle Compression Method.

[0322] Paragraph C. The disposable absorbent article of Paragraph A or B, wherein at least one of the upper and lower nonwoven layers is an air-bonded or hydroentangled nonwoven.

[0323] Paragraph D. The disposable absorbent article of any of Paragraphs A to C, wherein the polymeric fibers of the upper nonwoven layer have a fiber length of from 10 mm to 100 mm, preferably from 20 mm to 50 mm.

[0324] Paragraph E. The disposable absorbent article of any of Paragraphs A-D, wherein the polymeric fibers of the upper nonwoven layer have a fiber diameter of 2.0 DTex to 10 DTex and the polymeric fibers of the lower nonwoven layer have a fiber diameter of 1.7 DTex to 5 DTex.

[0325] Paragraph F. The disposable absorbent article of any of Paragraphs A-E, wherein the topsheet is in direct contact with the upper nonwoven layer, and the upper nonwoven layer is in direct contact with the inner core layer.

[0326] Paragraph G. The disposable absorbent article of any of Paragraphs A-F, having a dry caliper, measured according to the wet and dry CD and MD 3 point method, of from about 2.0 mm to about 6.0 mm.

[0327] Paragraph H. The disposable absorbent article of any of Paragraphs A-G, having an average density of from about 0.045 g / cm3 to about 0.16 g / cm3.

[0328] Paragraph I. The disposable absorbent article of any of Paragraphs A-H, wherein the upper nonwoven layer fibers comprise from about 70% to about 100% synthetic fibers and from about 0% to about 40% regenerated cellulose fibers including rayon.

[0329] Paragraph J. The disposable absorbent article of any of Paragraphs A-I, wherein at least a portion of the topsheet comprises an anti-stick agent.

[0330] Paragraph K. A disposable absorbent article comprising: A top sheet; Back seat and an absorbent core structure disposed between a topsheet and a backsheet, (a) an upper nonwoven layer comprising polymeric fibers, the upper nonwoven layer having a thickness of about 0.3 mm to about 1.3 mm at a pressure of 7 g / cm2, when measured according to the thickness-pressure method; (b) a lower nonwoven layer comprising polymeric fibers, the lower nonwoven layer having a thickness of about 0.1 mm to about 1.3 mm at a pressure of 7 g / cm2, and a basis weight less than or equal to the basis weight of the elastic upper nonwoven layer, when measured according to the thickness-pressure method; (c) an absorbent core structure comprising an inner core layer disposed between the upper nonwoven layer and the lower nonwoven layer; the inner core layer comprises cellulosic fibers of about 125 gsm to about 400 gsm; The absorbent core structure has an average density of about 0.045 g / cm3 to about 0.15 g / cm3, A disposable absorbent article, wherein the upper nonwoven layer has a Wet Penetration Time of less than about 4 seconds as measured according to the Wet Penetration Time Method.

[0331] Paragraph L. The disposable absorbent article of Paragraph K, wherein the inner core layer comprises from about 20 gsm to about 100 gsm of superabsorbent particles.

[0332] Paragraph M. The disposable absorbent article of Paragraph K or L, wherein the upper nonwoven layer has a thickness of about 0.2 mm to about 0.7 mm at a pressure of 70 g / cm2, when measured according to the Thickness-Pressure Method.

[0333] Paragraph N. The disposable absorbent article of any one of Paragraphs K-M, wherein the upper nonwoven layer has a permeability of from about 150 Darcy to about 1000 Darcy when measured according to a Permeability Measurement Method.

[0334] Paragraph O. The disposable absorbent article of any of Paragraphs K-N, wherein the upper nonwoven layer has a capillary action potential of from about 200 mJ / m2 to about 400 mJ / m2 as measured according to a pore volume distribution method.

[0335] Paragraph P. The disposable absorbent article of any one of Paragraphs K-O, wherein the polymeric fibers of the upper nonwoven have a fiber diameter of about 2.0 DTex to about 10 DTex and the polymeric fibers of the lower nonwoven have a fiber diameter of about 1.7 DTex to about 5 DTex.

[0336] Paragraph Q. The disposable absorbent article of any one of Paragraphs K-O, wherein the polymeric fibers of the upper nonwoven layer are selected from polyethylene terephthalate, polypropylene, polylactic acid, bicomponent fibers including polyethylene / polypropylene or polyethylene / polyethylene terephthalate, and combinations thereof.

[0337] Paragraph R. The disposable absorbent article of any one of Paragraphs K-Q, wherein the polymeric fibers of the lower nonwoven layer are selected from polyethylene terephthalate, polypropylene, polylactic acid, bicomponent fibers including polyethylene / polypropylene or polyethylene / polyethylene terephthalate, and combinations thereof.

[0338] Paragraph S. The disposable absorbent article of any one of Paragraphs K-R, wherein the polymeric fibers of the upper nonwoven layer have a fiber length of from about 10 mm to about 100 mm.

[0339] Dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

[0340] All documents cited herein, including cross-referenced documents or related patents or applications, are incorporated herein by reference in their entirety, unless expressly excluded or otherwise limited. The citation of any document shall not be deemed to be prior art to any invention disclosed or claimed herein, or to teach, suggest, or disclose any such invention, either alone or in combination with any other reference or references. Furthermore, if any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition given to that term in this document shall control.

[0341] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

1. 1. A disposable absorbent article comprising: A top sheet; Back seat and an absorbent core structure disposed between the topsheet and the backsheet, (a) an upper nonwoven layer comprising polymeric fibers; (b) a lower nonwoven layer comprising polymeric fibers; and (c) an absorbent core structure comprising an inner core layer disposed between the upper nonwoven layer and the lower nonwoven layer, the inner core layer comprising 50% to 85% cellulosic fibers by weight of the inner core layer and superabsorbent particles; Including, the inner core layer is contained within the nonwoven layers by substantially sealing at least the left and right regions of the upper and lower nonwoven layers with a perimeter seal; The disposable absorbent article has a CD dry bending stiffness, measured according to the wet and dry CD and MD 3-point bending method, of 10 N.mm2 to 30 N.mm2, and a total IFF+SFF value, measured according to the acquisition time and rewet method, of 20 mg to 200 mg.

2. 10. The disposable absorbent article of claim 1, wherein said absorbent article has a 5th cycle % Wet Recovery of 29% to 40% as measured according to the Wet and Dry Bundle Compression Method.

3. The disposable absorbent article of claim 1 or 2, wherein at least one of the upper nonwoven layer and the lower nonwoven layer is a through-bonded nonwoven or a hydroentangled nonwoven.

4. The disposable absorbent article according to any one of claims 1 to 3, wherein said polymeric fibres of said upper nonwoven layer have a fibre length of from 10mm to 100mm, preferably from 20mm to 50mm.

5. 5. The disposable absorbent article of any one of claims 1 to 4, wherein the polymer fibers of the upper nonwoven layer have a fiber diameter of 2.0 DTex to 10 DTex and the polymer fibers of the lower nonwoven layer have a fiber diameter of 1.7 DTex to 5 DTex.

6. The disposable absorbent article of any one of claims 1 to 5, wherein said topsheet is in direct contact with said upper nonwoven layer, and said upper nonwoven layer is in direct contact with said inner core layer.

7. The disposable absorbent article of any one of claims 1 to 6, having a dry caliper, measured according to the wet and dry CD and MD 3 point method, of 2.0 mm to 6.0 mm.

8. The disposable absorbent article of any one of claims 1 to 7, having an average density of 0.045 g / cm3 to 0.15 g / cm3.

9. The disposable absorbent article according to any one of claims 1 to 8, wherein the fibers of the upper nonwoven layer comprise 70-100% synthetic fibers and 0-40% regenerated cellulose fibers including rayon.

10. The disposable absorbent article of any one of claims 1 to 9, wherein at least a portion of the topsheet comprises an anti-stick agent.

11. 1. A disposable absorbent article comprising: A top sheet; Back seat and an absorbent core structure disposed between the topsheet and the backsheet, (a) an upper nonwoven layer comprising polymeric fibers, the upper nonwoven layer having a thickness of 0.3 mm to 1.3 mm at a pressure of 7 g / cm2, as measured according to the Thickness-Pressure Method; (b) a lower nonwoven layer comprising polymeric fibers, the lower nonwoven layer having a thickness of 0.1 mm to 1.3 mm at a pressure of 7 g / cm2, when measured according to the Thickness-Pressure Method, and a basis weight less than or equal to the basis weight of the elastic upper nonwoven layer; (c) an absorbent core structure comprising an inner core layer disposed between the upper nonwoven layer and the lower nonwoven layer; and Including, the inner core layer comprises 125 gsm to 400 gsm cellulosic fibers; the absorbent core structure has an average density of 0.045 g / cm3 to 0.15 g / cm3; A disposable absorbent article, wherein said upper nonwoven layer has a Wet Penetration Time of less than 4 seconds as measured according to the Wet Penetration Time Method.

12. The disposable absorbent article of claim 11, wherein said inner core layer comprises from 20 gsm to 100 gsm of superabsorbent particles.

13. The disposable absorbent article according to claim 11 or 12, wherein said upper nonwoven layer has a thickness of 0.2 mm to 0.7 mm at a pressure of 70 g / cm2, as measured according to the thickness-pressure method.

14. The disposable absorbent article according to any one of claims 11 to 13, wherein said upper nonwoven layer has a permeability of between 150 Darcy and 1000 Darcy when measured according to a Permeability Measurement Method.

15. The disposable absorbent article according to any one of claims 11 to 14, wherein said upper nonwoven layer has a capillary action potential of 200 mJ / m2 to 400 mJ / m2 as measured according to a pore volume distribution method.

16. The disposable absorbent article according to any one of claims 11 to 15, wherein the polymeric fibers of the upper nonwoven have a fiber diameter of 2.0 DTex to 10 DTex and the polymeric fibers of the lower nonwoven have a fiber diameter of 1.7 DTex to 5 DTex.

17. 17. The disposable absorbent article of any one of claims 11 to 16, wherein the polymeric fibers of the upper nonwoven layer are selected from polyethylene terephthalate, polypropylene, polylactic acid, bicomponent fibers including polyethylene / polypropylene or polyethylene / polyethylene terephthalate, and combinations thereof.

18. 18. The disposable absorbent article of any one of claims 11 to 17, wherein the polymeric fibers of the lower nonwoven layer are selected from polyethylene terephthalate, polypropylene, polylactic acid, bicomponent fibers including polyethylene / polypropylene or polyethylene / polyethylene terephthalate, and combinations thereof.

19. The disposable absorbent article according to any one of claims 11 to 18, wherein the polymeric fibers of the upper nonwoven layer have a fiber length of from 10 mm to 100 mm.

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