Fluid management layer for absorbent articles

Abstract

A fluid management layer comprising a nonwoven having a basis weight of from about 40 gsm to about 75 gsm, from about 15 wt% to about 35 wt% cellulosic fibers, from about 65 wt% to about 85 wt% binder fibers, wherein the fluid management layer has a caliper factor of from about 0.26 to about 0.35, and wherein the cellulosic fibers and the binder fibers have a denier per filament of less than about 2. The fluid management layer can be included in a disposable absorbent article.

Description

Technical Field

[0001] This disclosure relates in general to fluid management layers for disposable absorbent articles, and more specifically to fluid management layers for needle-punched nonwoven layers with improved performance characteristics. Background Technology

[0002] Disposable absorbent products such as feminine hygiene products, adhesive diapers, panty liners, and incontinence products are designed to absorb fluid from the wearer's body. Users of such disposable absorbent products have several concerns. For example, leakage from products such as menstrual pads, diapers, sanitary napkins, and incontinence liners is a significant concern. Additionally, the product's fit and comfort against the wearer's body are also important considerations. To provide better comfort, current disposable absorbent products typically include a topsheet that is flexible, soft to the touch, and non-irritating to the wearer's skin. The topsheet itself does not contain the leaked fluid. Instead, it is fluid-permeable to allow fluid to flow into the absorbent core.

[0003] Regarding comfort, some consumers may expect products to have sufficient thickness and stiffness to provide the desired amount of protection, while also being flexible. Loose, elastic materials can be used to provide a cushiony feeling in articles. However, during use, these loose, elastic materials undergo various compressive loads. Recovery from these compressive loads is crucial in maintaining the cushiony feeling of the article. Adding to this problem is the fact that once fluid is introduced into an absorbent article, the material properties of the article change. Therefore, an article that meets the necessary standards for consumers before use may no longer be comfortable, flexible, or have the desired stiffness for the user after the absorbent article has absorbed a given amount of fluid.

[0004] Therefore, there is a need to develop fluid management materials that have sufficient thickness and the recovery properties desired by consumers for use in absorbent articles, while still providing sufficient capillary action to facilitate fluid movement from the top sheet of the product to the absorbent core. Summary of the Invention

[0005] This document discloses a fluid management layer comprising: a nonwoven fabric having a basis weight of about 40 gsm to about 75 gsm, about 15 wt% to about 35 wt% of cellulose fibers, and about 65 wt% to about 85 wt% of binder fibers, wherein the fluid management layer has a thickness factor of about 0.26 to about 0.35, and wherein the cellulose fibers and the binder fibers have a denier of less than about 2.

[0006] This article also discloses a disposable absorbent article comprising a top sheet, a bottom sheet, an absorbent core disposed between the top sheet and the bottom sheet, and a fluid management layer disposed between the top sheet and the absorbent core, wherein the fluid management layer comprises a nonwoven fabric having a basis weight of about 40 gsm to about 75 gsm, about 15 wt% to about 35 wt% of cellulose fibers, and about 65 wt% to about 85 wt% of binder fibers, wherein the fluid management layer has a thickness factor of about 0.26 to about 0.35, and wherein the cellulose fibers and the polymer fibers have a denier of less than about 2. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a disposable absorbent article constructed according to this disclosure;

[0008] Figure 2 This is a schematic diagram of a disposable absorbent article constructed according to this disclosure;

[0009] Figure 3 This is a top view of the fluid management layer (without crossovers for comparison).

[0010] Figure 4 It is a top view of the fluid management layer with needles;

[0011] Figure 5 It is a top view of the fluid management layer with a needle cross-section showing a vertical needle bundle;

[0012] Figure 6 This is a top view of the fluid management layer with capillary enhancement points.

[0013] Figure 7 This is a schematic diagram of an asymmetrical wing;

[0014] Figures 8 to 11 Including equipment for data collection time and resuspension methods; and

[0015] Figures 12 to 16 Includes equipment views and diagrams for cohesive compression and bending length testing. Detailed Implementation

[0016] definition

[0017] As used herein, the following terms shall have the meanings specified below:

[0018] "Absorbent articles" refers to wearable devices that absorb and / or contain liquids, and more specifically, devices that are placed in close contact with or adjacent to the wearer's body for absorbing and containing various bodily excretions. Absorbent articles may include diapers, training pants, adult incontinence underwear (e.g., linings, pads, and shorts) and / or feminine hygiene products, including feminine sanitary pads (also known as, for example, "sanitary napkins," "menstrual pads," "panty liners," etc.).

[0019] As used herein, the term "integrated" describes fibers in nonwoven materials that have been interwoven, entangled, and / or pushed / pulled in the positive and / or negative Z-directions (the thickness direction of the nonwoven material). Some exemplary methods for integrating fibers in a nonwoven fiber web include hydroentangling and needle punching. Hydroentangling (also known as "hydraulic needle punching" or "water-reinforced") uses multiple jets of high-pressure water directed at precursor fibers or aggregates being conveyed along the machine direction to entangle the fibers. Needle punching (also known as "needle punching") involves using specially designed needles to mechanically push and / or pull fibers, precursor fibers, or aggregates in the Z-direction to entangle them with other fibers within the fibers or aggregates.

[0020] As used herein, the term "combed" is used to describe the structural characteristics of the fluid management layer described herein. Combed nonwoven fiber webs are formed from fibers cut to specific finite lengths, these fibers are also referred to as "short-length fibers." Short-length fibers can have any chosen length. For example, short-length fibers can be cut to lengths ranging from up to 120 mm to as short as 10 mm. However, if a particular group of fibers is short-length, then each fiber in the combed nonwoven fabric is substantially the same length, i.e., short-length. In the case of a nonwoven fiber web (e.g., a fiber web comprising polypropylene fibers and viscose fibers) comprising fibers of more than one composition, each fiber of the same composition may be substantially the same length, while the corresponding short fiber lengths of the respective fiber compositions may differ.

[0021] In contrast to short fibers, filaments, such as those produced by spinning, for example in spunbond or meltblown nonwoven fiber web manufacturing methods, are not typically short-length fibers. Instead, these filaments are sometimes characterized as “continuous” fibers, meaning they have a relatively long and indefinite length and are not cut to specific lengths after spinning, as their short-fiber counterparts would.

[0022] "Lateral" – in relation to absorbent articles such as feminine sanitary pads or components thereof, refers to the direction parallel to a horizontal line tangent to the front surface of the upper portion of the wearer's legs adjacent to the torso when the pad is worn normally and the wearer is in a flat, square, normal standing position. The "width" dimension of any part or feature of an article such as a feminine sanitary pad is measured in the lateral direction. When the article or component thereof is laid flat on a horizontal surface, the "lateral" direction corresponds to the lateral direction relative to the structure when it is worn, as defined above. In relation to an article such as a feminine sanitary pad opened and laid flat on a horizontal plane, "lateral" means a direction perpendicular to the longitudinal direction and parallel to the horizontal plane.

[0023] The "lateral axis" of absorbent articles such as feminine sanitary pads or components thereof is a lateral line located in the xy plane, and when the pad or component thereof is laid flat on a horizontal surface, the lateral line bisects the length of the pad or component thereof. The lateral axis is perpendicular to the longitudinal axis.

[0024] "Longitudinal" – relative to absorbent articles such as feminine pads or components thereof, refers to the direction perpendicular to the lateral direction. The "length" dimension of any part or feature of the article is measured longitudinally from its forward extent to its rearward extent. When an article such as a feminine pad or component thereof is laid flat on a horizontal surface, the "longitudinal" direction is perpendicular to the lateral direction relative to the pad when it is worn, as defined above.

[0025] The "longitudinal axis" of a feminine sanitary pad or its components is a longitudinal line located in the xy plane, and when the pad is laid flat on a horizontal surface, the longitudinal line bisects the width of the pad or its components. The longitudinal axis is perpendicular to the lateral axis.

[0026] Regarding absorbent articles such as feminine sanitary pads or their components, when laid flat on a horizontal surface, the "xy plane" refers to any horizontal plane occupied by any layer of that horizontal surface or article or component.

[0027] Regarding absorbent products (such as feminine hygiene pads or components thereof), when laid flat on a horizontal surface, the "z-direction" is the direction perpendicular to / orthogonal to the xy plane.

[0028] The terms “top,” “bottom,” “upper,” “lower,” “above,” “below,” “under,” “upper adjacent,” “lower adjacent,” and similar terms relating to relative vertical positioning, when used herein to refer to a layer, component, or other feature of an absorbent article (such as a feminine sanitary pad), are relative to the z-direction and will be interpreted relative to the pad as it would appear when it is laid flat on a horizontal surface, wherein the wearer-facing surface of the pad is oriented upward and the outward-facing surface is oriented downward.

[0029] In relation to absorbent articles such as feminine hygiene pads, or their components or structures, "wear-facing" is a relative positional term that refers to a feature of a component or structure that is closer to the wearer than another feature of the component or structure during use. For example, a topsheet has a wear-facing surface that is closer to the wearer than the opposite, outward-facing surface of the topsheet.

[0030] In relation to absorbent articles such as feminine hygiene pads, or their components or structures, "outward-facing" is a relative positional term that refers to a feature of a component or structure that is further away from the wearer than another feature of the component or structure during use. For example, a topsheet has an outward-facing surface that is further away from the wearer than its opposite, wear-facing surface.

[0031] As used herein, in relation to absorbent articles such as feminine sanitary pads or their components, "longitudinal" or "MD" refers to the direction parallel to the flow of the article or component through the processing / manufacturing equipment.

[0032] As used herein, in relation to absorbent products such as feminine sanitary pads or components thereof, "lateral" or "CD" refers to a direction perpendicular to / orthogonal to the longitudinal direction.

[0033] When used to characterize the amount of weight, volume, surface area, etc. of an absorbent article or its component composed of a composition, material, feature, etc., "major" and its forms mean that such weight, volume, surface area, etc. of the absorbent article or its component is composed of the composition, material, feature, etc.

[0034] General absorbent products; feminine sanitary pads

[0035] refer to Figure 1 As envisioned herein, absorbent articles such as feminine sanitary pads 10 would include a wearer-facing surface and an opposing outward-facing surface. A liquid-permeable top sheet 20 may form at least a portion of the wearer-facing surface, and a liquid-impermeable bottom sheet may form at least a portion of the outward-facing surface. The absorbent core includes an absorbent structure 40 disposed between the top sheet and the bottom sheet, and a fluid management layer 30 may be included and disposed between the absorbent structure 40 and the top sheet 20. (The fluid management layer as described herein is sometimes referred to in the art as a “collection / distribution layer,” “distribution layer,” or “second top sheet,” and its purpose is to dissipate the energy from fluid outflow to a desired extent, provide temporary space volume for the discharged fluid to occupy during the time required for the lower absorbent structure to receive and absorb the fluid, and distribute the fluid through the absorbent structure to maximize its effective utilization.) Non-limiting examples of absorbent articles sharing these features include feminine sanitary pads (also known as “sanitary napkins,” “menstrual pads,” etc.), disposable incontinence pads, disposable incontinence underwear, disposable baby diapers, and disposable baby / child training pants.

[0036] The top sheet 20 and the bottom sheet 50 can be joined together to form and define the outer periphery of the pad 10. The absorbent structure 40 and the fluid management layer 30 will each be dimensioned to have an outer periphery laterally and longitudinally disposed inside the outer periphery. The dimensions and shapes of the absorbent structure 40 and the fluid management layer 30 in the xy directions may be substantially similar or identical to each other, or they may have correspondingly different xy dimensions and / or shapes. One or both may be manufactured to have, for example... Figure 1 The rectangular shape suggested herein, or one or both, can be manufactured in any other suitable shape, such as oval, stadium, rounded rectangle, hourglass, peanut, etc. Shapes with a concave profile along the longitudinal edge may provide enhanced comfort and / or a better fit to the wearer's body in some examples.

[0037] The top sheet 20 can be bonded to the bottom sheet 50 by any suitable attachment mechanism. The top sheet 20 and the bottom sheet 50 can be directly bonded to each other in the periphery of the article, and can also be indirectly bonded together by directly bonding them to the absorbent structure 40, the fluid management layer 30, and / or an additional layer disposed between the top sheet 20 and the bottom sheet 50. This indirect or direct bonding can be achieved by any suitable attachment mechanism known in the art. Non-limiting examples of attachment mechanisms may include, for example, fusion bonding, ultrasonic bonding, pressure bonding, adhesive bonding, or any suitable combination thereof. The absorbent article 10 may also include wings 60 extending outward relative to the longitudinal axis 80 of the absorbent article 10. The absorbent article 10 may also include a lateral axis 90. Figure 7 As shown, the wings can be asymmetrical, such as those disclosed, for example, in U.S. Patent Publications 2022 / 0409449, 2021 / 0307977, 2018 / 0325750, and 2018 / 0325751, all of which are incorporated herein by reference. References Figure 2The disposable absorbent article 100 has a top sheet 110, a bottom sheet 120, an absorbent core 130 disposed between the top sheet and the bottom sheet, and a fluid management layer 140 disposed between the top sheet and the absorbent core. The absorbent article 100 may have a fluid management layer 140 comprising a nonwoven fabric having a basis weight of about 40 gsm to about 75 gsm, about 15 wt% to about 35 wt% cellulose fibers, and about 65 wt% to about 85 wt% binder fibers. The fluid management layer may have a thickness factor (mm / 10 gsm) of about 0.26 to about 0.35, and the cellulose fibers and polymer fibers may have a denier of less than about 2. The absorbent article may have a Z-compression energy of about 2.6 N·mm to about 4.0 N·mm, a 3-point MD flexural dry stiffness of about 15 N·mm² to about 40 N·mm², and a wet-state coalescing compression recovery of more than about 40%. The absorbent article 100 may have a longitudinal axis 180. The absorbent article 100 may also include a lateral axis 190.

[0038] Top film

[0039] General Instructions

[0040] The topsheet 20 is typically expected to be compliant, soft to the touch, and non-irritating to the wearer's skin. Suitable topsheet materials include liquid-permeable materials that are oriented towards and in contact with the wearer's body, allowing bodily excretions to pass through quickly without allowing fluid to flow back onto the wearer's skin. While the topsheet allows fluid to pass through and be rapidly transferred, it can also allow the lotion composition to transfer or migrate to external or internal portions of the wearer's skin. The topsheet may include nonwoven materials.

[0041] The nonwoven fiber top sheet 20 can be produced by any known process for manufacturing nonwoven fiber webs. Non-limiting examples of such processes include spunbond, carding, wet web forming, air-laid web forming, meltblown, needle punching, mechanical winding, thermo-mechanical winding, and hydroentangling.

[0042] Suitable nonwoven materials for use as topsheets may include a single fiber layer or a laminate that may consist of multiple nonwoven layers, the laminate comprising the same or different compositions (e.g., a spunbond-meltblown laminate). In a specific example, the topsheet is a carded, breathable bonded nonwoven.

[0043] The topsheet envisioned herein does not include any major portion of the topsheet's xy surface area occupied by the membrane. Some currently known topsheets for feminine hygiene pads include open-cell membranes, such as hydroformed or vacuum-formed membranes, alone or in combination with adjacent nonwoven fiber web materials. This membrane helps prevent liquid re-emergence and contact with the wearer. However, the inventors have discovered that topsheets having the features described herein, particularly those combined with the fluid management layer described herein, can effectively prevent backflow to a degree comparable to or better than that of pads with topsheets having a membrane comprising a major portion of the topsheet's xy surface area. Without being bound by theory, it is believed that careful selection of the fiber type and linear density of each layer in the fluid management layer can result in a desirable combination of adequately rapid collection and low backflow, overcoming the typical trade-offs among these conflicting objectives associated with existing nonwoven topsheets. The improved performance is evident from the novel combination of the unique nonwoven topsheet with the fluid management layer of this disclosure.

[0044] Basis weight

[0045] Topsheet nonwovens can be manufactured with a basis weight of at least about 15 gsm, and alternatively up to about 60 gsm, with all values ​​within these ranges and any ranges arising therefrom listed. In some examples, the nonwoven topsheets envisioned herein can be manufactured with a basis weight of about 15 gsm to 60 gsm, alternatively about 18 gsm to 40 gsm, and alternatively about 20 gsm to 30 gsm, with all values ​​within these ranges and any ranges arising therefrom listed. Suitable topsheet nonwovens can be manufactured with a basis weight of about 18 gsm to 40 gsm, alternatively about 20 gsm to 30 gsm, and alternatively about 22 gsm to 26 gsm, with all values ​​within these ranges and any ranges arising therefrom listed. The ideal basis weight range, at the lower limit of this range, is influenced by the required level of tensile strength of the fiber web for processing and by substantial consumer preferences for opacity levels and thickness, feel, and appearance. The ideal basis weight range is influenced by the upper limit of the range, which is affected by the need for suitable rapid fluid acquisition and fluid passage through the top plate, as well as material cost considerations.

[0046] Fiber Composition

[0047] Non-limiting examples of woven and nonwoven materials suitable for use as topsheets include fibrous materials made from natural fibers (e.g., cotton, including 100% organic cotton), modified natural fibers, semi-synthetic fibers (e.g., fibers spun from regenerated cellulose), synthetic fibers (e.g., fibers spun from polymer resins), or combinations thereof. Synthetic fibers may include fibers spun from a single polymer or blends of polymers. Synthetic fibers may include monocomponent fibers, bicomponent fibers, or multicomponent fibers. (Hereinafter, bicomponent or multicomponent fibers are fibers having a cross-section divided into clearly identifiable component portions, each formed from a single polymer or a blend of a single homogeneous polymer, distinct from the other portions. Such fibers and methods for preparing them are known in the art. Examples of bicomponent fiber constructions having a substantially circular cross-section include side-by-side or “fan-shaped” constructions, eccentric core-sheath constructions, and concentric core-sheath constructions.)

[0048] The nonwoven topsheets envisioned herein may comprise fibers having numerous combinations of constituent chemical substances. For example, the fibers may be spun from polymeric materials such as polyethylene (PE) and / or polyethylene terephthalate (PET). The fibers may be spun in the form of bicomponent fibers. In some examples, the bicomponent fibers may have a core component of a first polymer (e.g., PET) and a sheath component of another polymer, forming a core-sheath bicomponent structure. In a more specific example, PE may be combined with a PET core component to form the sheath component. Fibers that optionally include a PET component may help provide the nonwoven fiber web with body and resilience, as well as the resulting cushioned feel. Furthermore, fibers that include a resilient PET component help the fiber web retain the area and size of the openings (if included) formed therethrough.

[0049] Other polymeric materials may be included. For example, fibers spun from polypropylene, polyethylene, copolymer polyethylene terephthalate, copolypropylene, and other thermoplastic resins may be included. It may be desirable for polymers with lower melting temperatures to form the sheath component, including core-sheath bicomponent fibers. Furthermore, it is not desirable to be bound by theory; it is believed that using polyethylene terephthalate as the core can help impart resilience to the top sheet.

[0050] Compared to other potentially useful polymers, polyethylene, as the polymer component from which it can be spun into fibers, has a relatively low melt temperature and exhibits a relatively smooth / silky surface feel. PET has a relatively high melt temperature and exhibits relatively high stiffness and resilience. Therefore, in some examples, topsheet nonwoven fibers with a core-sheath bicomponent structure are desirable, wherein the sheath component is primarily polyethylene and the core component is primarily PET. Polyethylene can be used to impart a silky feel to the fiber and thus to the topsheet, and can be used to achieve interfiber bonding by causing the sheaths of adjacent / contacting fibers to melt and fuse at the lower melt temperature of polyethylene through heat treatment, while PET can be used to impart resilience and does not melt during heat treatment. The inventors have found that a suitable weight ratio in such PE / PET core-sheath bicomponent fibers can be from about 40:60 to about 60:40.

[0051] Surface treatment (hydrophilic / hydrophobic)

[0052] Depending on the chemical composition of the fiber, the surface of the fiber will inherently be either hydrophilic or hydrophobic to varying degrees. For example, the surface of fibers spun from or otherwise formed from some types of polymers, such as polyethylene and polypropylene, will inherently be hydrophobic. Conversely, the surface of other types of fibers, such as rayon fibers, will inherently be hydrophilic. The surface of natural fibers can inherently be hydrophilic or hydrophobic, but this may depend on the processing the fiber has undergone. For example, harvested cotton fibers have a coating of natural oils and / or waxes, and therefore their surfaces are hydrophobic. However, after they have undergone processes including scrubbing and bleaching, the oils and / or waxes are removed, making the fiber surface hydrophilic.

[0053] Manufacturers and / or suppliers of spun synthetic staple fibers currently apply coatings, in the form of surface finishing agents or processing aids, to the fibers for the purpose of providing lubrication, for example, during carding processes. These surface finishing agents or processing aids can be formulated to be hydrophobic or hydrophilic and are substantially durable for the purposes of this article, as they will not dissolve in aqueous fluids during the normal wearing duration of absorbent articles. Therefore, manufacturers or suppliers of spun synthetic staple fibers can provide fibers with hydrophobic or hydrophilic surface finishes, and currently, several manufacturers in the nonwoven materials industry do so.

[0054] It is worth noting that spun synthetic staple fibers may have an inherently hydrophobic or hydrophilic surface, or a surface finish that makes the surface hydrophilic or hydrophobic depending on the purchaser's choice. It may be desirable to choose fibers with a hydrophilic ("hydrophilic fiber") or hydrophobic ("hydrophobic fiber") surface, or a blend of the two types of fibers.

[0055] In some examples, the fiber composition of the topsheet is preferably predominantly, substantially, or completely hydrophobic by weight, or is endowed with hydrophobicity through the smoothness of the fiber surface. A topsheet formed from a nonwoven fiber web predominantly possessing hydrophobic fiber components will resist backflow. On the other hand, if the size of the pores or interfiber gaps within the fiber structure of such a nonwoven fiber web is not sufficiently large, the topsheet may prevent fluid from passing from the wearer-facing surface through to the absorbent core of the article beneath it; that is, fluid will not be easily / quickly collected unless other features as described herein are included in combination.

[0056] In other examples, part, most (by surface area), or all of the fibers constituting the cross-section of the fiber web material forming the topsheet may be a blend of both hydrophobic and hydrophilic fibers. In such examples, the hydrophilic fibers can be used to help fluid be drawn from the wearer-facing surface of the topsheet downwards to the absorbent core component below, while the hydrophobic fibers can be used to help the topsheet prevent backflow. The inventors have found that a successful balance can be achieved for such examples.

[0057] Therefore, in some examples, the topsheet nonwoven fabric may comprise a mixture of hydrophobic and hydrophilic fibers. For example, the nonwoven fabric may comprise at least about 40%, alternatively at least about 50%, or alternatively at least about 60% by weight of hydrophilic fibers, specifically including all values ​​within these ranges and any ranges arising therefrom. In more specific examples, the nonwoven topsheet may comprise about 40% to 70% by weight, alternatively about 45% to 68% by weight, or alternatively about 50% to 65% by weight of hydrophilic fibers, specifically listing all values ​​within these ranges and any ranges arising therefrom. The topsheet nonwoven fabric may comprise a blend of hydrophilic and hydrophobic fibers in a weight ratio of hydrophilic to hydrophobic fibers of 30:70 to 70:30, alternatively 35:65 to 65:35, and alternatively 40:60 to 60:40. As mentioned above, the hydrophilicity of the hydrophilic fibers can be influenced by applying a surface treatment composition.

[0058] Without being bound by theory, it is believed that, when most fibers are hydrophilic, fluid collection rates can be improved by combining them with other features described herein without unduly impacting reflow in an unfavorable or unacceptably detrimental manner. The opposite may be true when the goal is less reflow. In this case, a higher weight fraction of hydrophobic fibers might be desirable.

[0059] Linear density

[0060] Fibers are typically manufactured, selected, and purchased using linear density specifications, such as denier or fensterel. For a fiber with a given polymer composition, linear density is related to fiber size / diameter.

[0061] In some examples, the fibers constituting the top sheet may be selected to have an average linear density of about 1.0 denier to 3.0 denier, alternatively about 1.5 denier to 2.5 denier, and alternatively about 1.8 denier to 2.2 denier, and all combinations of subranges within these ranges are contemplated herein. Fibers having linear densities varying within the aforementioned ranges may also be selected and included.

[0062] In other examples, the fibers constituting the topsheet may be selected to have an average linear density of about 3.0 denier to 5.0 denier, alternatively about 3.5 denier to 4.5 denier, and alternatively about 3.8 denier to 4.2 denier, and all combinations of subranges within these ranges are contemplated herein. It is understood that fibers selected within these ranges, combined with other characteristics disclosed herein, can be considered as topsheet materials that provide a range of consumer-acceptable softness and other advantages over smaller fibers.

[0063] One advantage is that relatively larger fibers typically provide a nonwoven fabric with relatively large spaces or voids between fibers / within the fiber web, thus providing larger channels through which fluid can travel more quickly through the nonwoven fabric from the wearer-facing side to the outer side (and therefore to the absorbent components beneath the topsheet). Additionally, while relatively larger fibers of a given composition are stiffer than smaller fibers of a similar composition, which may somewhat compromise the surface's "softness," the greater fiber stiffness can also enhance the greater resilience, elasticity, or cushioned feel of the topsheet nonwoven fabric.

[0064] short fiber length

[0065] Suitable fibers may be short fibers having lengths within the following ranges: at least about 30 mm, 40 mm, or 50 mm, and at most about 55 mm, or about 30 mm to about 55 mm, or about 35 mm to 52 mm, with increments of 1 mm listed for each range. In a specific example, the short fiber may have a length of about 38 mm.

[0066] The applied anti-adhesion agent

[0067] Absorbent articles may include an anti-adhesion agent applied to at least a portion of the wearer-facing surface of the topsheet, wherein the anti-adhesion agent comprises a polypropylene glycol material. It is believed that the applied anti-adhesion agent, as described herein, functions to reduce the adhesion of menstrual fluid to the user's / wearer's skin and to facilitate the migration of menstrual fluid down the wearer-facing surface of the topsheet through to the underlying fluid management and / or absorbent structural layers. Providing these functions enhances the user's / wearer's sense of cleanliness towards her / her skin and the topsheet, especially after repeated expulsion of menstrual fluid. Examples of suitable anti-adhesion agents and / or surfactants that may be used therein are disclosed in US 2009 / 0221978 (where the composition is referred to as a "loosening agent") and US 8,178,748.

[0068] Anti-adhesives may include polypropylene glycol (“PPG”) materials. In some examples, the anti-adhesive may consist essentially of a polypropylene glycol material (including, but not limited to, polypropylene glycol homopolymers such as polypropylene glycol) and an optional carrier. In other examples, the anti-adhesive may contain polypropylene glycol materials selected from the group consisting of polypropylene glycol copolymers, polypropylene glycol surfactants, and mixtures thereof. Anti-adhesives including polypropylene glycol materials can be used to help reduce fluid adhesion to the topsheet and to reduce fluid transfer to the user / wearer upon contact, thereby reducing fluid adhesion to her skin, thus reducing staining on the topsheet and dirt on the skin. Anti-adhesives may also help improve continuous fluid collection in absorbent articles.

[0069] The anti-adhesion agent can be applied to the wearer-facing surface of the topsheet 20 in any known manner and in any known pattern. For example, the anti-adhesion agent can be applied in a pattern of strips or bands that are typically parallel, longitudinal, or lateral. To avoid compression or displacement of the position of any part of the topsheet nonwoven fabric or any three-dimensional feature thereof, it is desirable to apply the anti-adhesion agent by spraying. Spraying can be applied substantially uniformly.

[0070] The amount of anti-adhesion applied can vary and be adjusted for specific needs. For example, without being bound by theory, it is believed that anti-adhesion can be applied at effective levels of at least about 0.1 gsm, 0.5 gsm, 1 gsm, 2 gsm, 3 gsm, 4 gsm, 5 gsm, 10 gsm, up to about 15 gsm, or up to about 12 gsm, or up to about 10 gsm. It is believed that efficacy will not be further enhanced above these upper limits, and therefore applying at a basis weight exceeding these upper limits may be an unnecessary (wasteful) use of anti-adhesion. Anti-adhesion can be applied within any sub-range defined by any of the above levels (e.g., from about 0.1 gsm to about 15 gsm). These levels refer to the area of ​​the top sheet surface to which the anti-adhesion is actually applied. Anti-adhesion can be applied over most, substantially all, or all of the surface area of ​​the top sheet covering the fluid management layer and / or the absorbent core. This is because, as is believed, anti-adhesion enhances the top sheet's ability to prevent backflow.

[0071] The anti-adhesion agents envisioned in this paper offer significant advantages over other anti-adhesion agents, including non-PPG-derived surfactants and other surface modifiers. These advantages can be considered particularly useful for feminine panty liners. Without being bound by theory, it is believed that the superior fluid handling properties of the PPG materials identified herein are a result of the way the PPG materials act on the solid components of menstrual fluid, in contrast to surface energy treatments acting on the aqueous components of menstrual flow. Surface energy treatments may be less effective due to the presence of polar and dispersible components in menstrual fluid, which can inhibit the effectiveness of surface energy treatments. Because the PPG materials identified herein are generally not readily soluble in menstrual fluid, they can effectively coat surfaces without dissolving in the fluid, providing a hydration barrier whose electron-donating dipoles repel negative dipole proteins, thus making it less likely for menstrual fluid to adhere to the surface of the product or the wearer's skin. Less adhesion of menstrual fluid to the wearer's skin and / or the topsheet promotes better and faster fluid movement through the topsheet and results in fewer, smaller, and / or less visible stain patterns on used products.

[0072] The PPG material identified herein may be applied as a component of the anti-adhesive, or it may be applied in its pure form (i.e., the anti-adhesive consists of PPG material). PPG material (pure and / or as part of the anti-adhesive) may be applied at varying levels depending on the desired fluid handling properties and the desired treatment of the wearer's skin. PPG material may be applied to the outer surface of the topsheet in any pattern, such as a full coating, strips or bands (oriented in the MD or CD direction), droplets, spiral patterns, and other designs. When present, anti-adhesives including PPG material may also be placed near channels or embossed areas.

[0073] The anti-adhesive contemplated herein may include PPG materials. PPG materials suitable for the purposes contemplated herein include PPG homopolymer materials, PPG copolymer materials, and PPG surfactant materials, as well as mixtures thereof. The anti-adhesive may also include other optional components. Suitable anti-adhesives comprise PPG materials, including but not limited to polypropylene glycol. Alternatively, the anti-adhesive comprises PPG materials selected from the group consisting of polypropylene glycol copolymers, polypropylene glycol surfactants, and mixtures thereof.

[0074] The anti-adhesion agents envisioned herein may comprise PPG material at levels ranging from about 0.1% to 100% by weight of the anti-adhesion agent. In some examples, the anti-adhesion agent may comprise less than about 10%, alternatively about 0.5% to 8%, and alternatively about 1% to 5% by weight of the anti-adhesion agent. The anti-adhesion agent may comprise at least about 50%, alternatively about 75% to 100%, and alternatively about 90% to 100% by weight of the anti-adhesion agent.

[0075] Suitable PPG homopolymer materials may include those corresponding to the following formula:

[0076]

[0077] - Wherein R is hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, benzyl, acetyl carbonyl, propionyl carbonyl, butyryl carbonyl, isobutyryl carbonyl, benzo[a]carbonyl, fumaryl carbonyl, aminobenzo[a]carbonyl, carboxymethyl, aminopropylene, alkylated glucose, alkylated sucrose, alkylated cellulose, alkylated starch, or phosphate ester; and wherein R can be hydrogen or methyl;

[0078] - Wherein R1 is hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, benzyl, acetylcarbonyl, propionylcarbonyl, butyrylcarbonyl, isobutyrylcarbonyl, benzo[a]carbonyl, fumaroylcarbonyl, aminobenzo[a]carbonyl, carboxymethyl, aminopropylene, alkylated glucose, alkylated sucrose, alkylated cellulose, alkylated starch, or phosphate ester; and wherein R1 can be hydrogen or methyl; and

[0079] - where n is 3 to 160, or 5 to 120, or 10 to 100, and or 20 to 80.

[0080] Optionally, the PPG homopolymer may include a low level of glycerol or butanediol as part of its monomer raw materials. If included, a suitable ratio of glycerol or butanediol to propylene glycol may be from about 1:1000 to about 1:2, or alternatively from about 1:100 to about 1:5. The PPG homopolymer may have, but is not limited to, CAS numbers 25322-69-4, 25791-96-2, and 25231-21-4.

[0081] Non-limiting examples of suitable PPG homopolymer materials include: polypropylene glycol 4000, such as Pluriol P-4000 (BASF), Alkapol PPG-4000 (Alkaril Chemical), and Niax Polyol PPG 4025 (UnionCarbide); polypropylene glycol 3500; polypropylene glycol 3000, such as Niax PPG 3025 (Union Carbide); polypropylene glycol 2000, such as Alkanol PPG-2000 (Alkaril Chemical) and Pluriol P-2000 (BASF); polypropylene glycol 1200, such as Alkapol PPG-1200 (Alkaril Chemical) and Glucam P-20 Humectant (Noveon); polypropylene glycol 1000, such as Niax PPG 1025 (Union Carbide); and polypropylene glycol 600, such as Alkanol PPG-600 (Alkaril Chemical) and Glucam P-10. Humectant (Noveon); Polypropylene glycol 400 such as Alkanol PPG-425 (Alkaril Chemical); Polypropylene glycol 4000 glycerol ether such as Pluriol T-4000 (BASF); Polypropylene glycol 2000 glycerol ether, Polypropylene glycol 2000 butylene glycol ether, Polypropylene glycol 1500 glycerol ether such as Pluriol T-1500 (BASF), Polypropylene glycol 4000 with monomethyl ether, Polypropylene glycol 2000 with dimethyl ether, Polypropylene glycol 4000 with monobutyl ether, Polypropylene glycol 2000 with monobutyl ether, Polypropylene glycol 1200 with dibutyl ether, Polypropylene glycol 4000 with bis(2-aminopropyl ether), PPG-10 methyl glucosyl ether and PPG-20 methyl glucosyl ether.

[0082] Suitable PPG homopolymer materials will typically have a number average molecular weight of about 400 to 10,000, alternatively about 600 to about 6,000 and alternatively about 1,200 to about 4,800.

[0083] Suitable PPG copolymer materials include those in which polypropylene glycol segments exist as internal block components and / or as terminal components in the copolymer structure. The following formulas illustrate internal block components and terminal block components:

[0084]

[0085] Wherein x is 2 to 120, alternatively 2 to 80 and alternatively 3 to 60; y is 2 to 100, alternatively 2 to 50 and alternatively 3 to 30; R2 is hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, benzyl, acetyl carbonyl, propionyl carbonyl, butyryl carbonyl, isobutyryl carbonyl, benzo[a]carbonyl, fumaryl carbonyl, aminobenzo[a]carbonyl, carboxymethyl, aminopropylene, alkylated glucose, alkylated sucrose, alkylated cellulose, alkylated starch or phosphate ester, and wherein R2 is hydrogen, methyl, ethyl, isopropyl or isobutyl.

[0086] Polymers suitable for forming propoxylated copolymers with PPG for use in the anti-adhesives of the present invention include homopolymers of alkyl polymethylsiloxanes, phenyl polymethylsiloxanes, dimethyl polysiloxanes, alkyl polytrimethylsiloxanes, phenyl polytrimethylsiloxanes, polyols, polyethers (e.g., polyoxymethylene, polyoxyethylene, and polyoxypropylene), polyimides, polyamides, polyacrylates, polyesters, and copolymers comprising one or more of these polymeric units. Non-limiting examples of suitable polymers include polydimethylsiloxane, polyethyleneimine, polyacrylic acid, poly(ethylene-co-acrylic acid), polymethacrylic acid, poly(ethylene-co-methacrylic acid), poly(vinyl acetate), polyvinylpyrrolidone, poly(ethylene-co-vinyl acetate), poly(butanediol), poly(neopentyl glycol), poly(ethylene adipate), poly(butylene adipate), poly(ethylene glutamate), poly(butylene glutamate), poly(ethylene sebacic acid), poly(butylene sebacic acid), poly(ethylene glycol sebacic acid), poly(ethylene glycol succinate), poly(butylene succinate), poly(ethylene terephthalate), poly(butylene terephthalate), polycaprolactone, and polyglycerol.

[0087] Non-limiting examples of suitable PPG copolymer materials include PPG-12 dimethylpolysiloxane, such as Sisoft910 (Momentive); bis-PPG-15 dimethylpolysiloxane / IPDI copolymers such as Polyderm-PPI-SI-WI (Alzo); PPG / polycaprolactone block copolymers; PPG / polybutanediol / PEG triblock copolymers; polyethylimide / PPG copolymers; and polyacrylic acid-g-PPG graft copolymers.

[0088] Another suitable PPG material includes PPG surfactant materials. The following formula represents a suitable PPG surfactant material, where PPG segments constitute part of the head functional group:

[0089]

[0090] Wherein R3 is hydrogen, alkyl, alkyl carbonyl, alkyleneamine, alkyleneamide, alkylene phosphate, alkylene carboxylic acid, alkylene sulfonate, and alkylene quaternary ammonium with a maximum carbon number of 6 or less; R4 is octyl, nonyl, decyl, isodecyl, lauryl, myristyl, cetyl, isohexadecyl, oleylene, stearyl, isostearyl, tartrate, linoleyl, jojoba oil, lanolin, dodecyl, C24-C28 alkyl, C30-C45 alkyl, dinonylphenyl, dodecylbenzene, or soybean; z is 1 to 100, alternatively 2 to 30, and alternatively 3 to 25; and F is a functional group selected from the group consisting of: ether groups (including oxy, glyceryl, glucose, sorbitol, sucrose, monoethanolamine, or diethanolamine), ester groups (including esters, glycerides, glucose esters, sorbitol esters, or sucrose esters), amine groups, amide groups, and phosphate groups.

[0091] The following formula represents a suitable PPG surfactant material, wherein the PPG segments constitute internal block groups:

[0092]

[0093] R5 is hexyl, 2-ethylhexyl, octyl, nonyl, decyl, isodecyl, lauryl, cocoyl, myristyl, cetyl, isohexadecanyl, oleylene, stearyl, isostearyl, tallowyl, linoleyl, octylphenyl, or nonylphenyl; r is 1 to 120, alternatively 4 to 50, and alternatively 6 to 30; and G is an ether, ester, amine, or amide bond.

[0094] Non-limiting examples of suitable PPG surfactant materials include PPG-30 cetyl ether, such as Hetoxol C30P (Global Seven); PPG-20 methyl glucoether distearate, such as Glucam P-20 distearate emollient (Noveon), PPG-20 methyl glucoether acetate, PPG-20 sorbitol tristearate, PPG-20 methyl glucoether distearate, PPG-20 distearate; PPG-15 stearyl ether, such as Alamol-E (Croda-Uniqema) and Procetyl 15 (Croda); PPG-15 stearyl ether benzoate, PPG-15 isohexadecanyl ether, PPG-15 stearate, PPG-15 discocoate, PPG-12 dilaurate; PPG-11 stearyl ether, such as Varonic APS (Evonik); PPG-10 cetyl ether, such as Procetyl 10 (Croda); PPG-10 glyceryl stearate, PPG-10 sorbitan monostearate, PPG-10 hydrogenated castor oil, PPG-10 cetyl phosphate, PPG-10 tallow amine, PPG-10 oleamide, PPG-10 cetyl ether phosphate, PPG-10 dinonylphenol ester, PPG-9 laurate, PPG-8 dicaprylate, PPG-8 diethylhexanoate, PPG-7 lauryl ether, PPG-5 lanolin wax ether, PPG-5 sucrose cocoate, PPG-5 lanolin wax, PPG-4 jojoba oil ether, PPG-4 lauryl ether, PPG-3 myristyl ether such as Promyristyl PM-3 (Croda), PPG-3 myristyl ether propionate such as Crodamol PMP (Croda), PPG-3 benzyl ether myristate such as Crodamol STS (Croda), PPG-3 hydrogenated castor oil such as Hetester HCP (Alzo), PPG-3-hydroxyethyl soy amide, PPG-2 cocamide, PPG-2 lanolin alcohol ether, and PPG-1 coconut fatty acid isopropanol amide such as Amizett IPC (Kawaken Fine Chemicals). Suitable PPG material is PPG-15 stearyl ether, such as products sold by BASF Corporation (Florum Park, NJ, USA) and / or BASF SE (Ludwigshafen, Germany) under the name CETIOL E.

[0095] The anti-adhesion agent envisioned in this paper may contain a total carrier concentration ranging from approximately 60% to 99.9% by weight of the anti-adhesion agent, alternatively from approximately 70% to 99.5%, and alternatively from approximately 80% to 99%.

[0096] Suitable carriers for this article may include oils or fats, such as natural oils or fats, or natural oils or fat derivatives, especially oils or fats of plant or animal origin. Non-limiting examples include avocado oil, apricot oil, almond oil, babassu kernel oil, borage oil, borage seed oil, calendula oil, camellia oil, canola seed oil, carrot oil, cashew oil, castor oil, chamomile oil, cherry pit oil, chia seed oil, coconut oil, cod liver oil, corn oil, corn germ oil, cottonseed oil, eucalyptus oil, evening primrose oil, grapeseed oil, hazelnut oil, jojoba oil, juniper oil, kernel oil, flaxseed oil, macadamia nut oil, meadowfoam seed oil, herring oil, mink oil, moringa oil, tarragon oil, olive oil, palm oil, palm kernel oil, peanut oil, peach kernel oil, rapeseed oil, rosehip oil, safflower oil, sandalwood oil, sesame oil, soybean oil, sunflower oil, sunflower seed oil, sweet almond oil, tall oil, tea tree oil, turnip seed oil, walnut oil, wheat germ oil, turmeric oil, or their hardened derivatives. Hardened oils or fats from plant sources may include, for example, hardened castor oil, peanut oil, soybean oil, turnip seed oil, cottonseed oil, sunflower oil, palm oil, walnut oil, flaxseed oil, corn oil, olive oil, sesame oil, cocoa butter, shea butter, and coconut oil.

[0097] Other non-limiting examples of fats and oils may include: butter, C12-C18 triglycerides, camellia oil, caprylic / capric / lauric triglycerides, caprylic / capric / linoleic triglycerides, caprylic / capric / stearic triglycerides, cocoa butter, C10-C18 triglycerides, egg oil, epoxidized soybean oil, glyceryl triacetyl hydroxystearate, glyceryl triacetyl ricinoleate, glycosphingolipids, and human placenta. Lipids, Hybrid Safflower Oil, Hybrid Sunflower Seed Oil, Hydrogenated Castor Oil, Hydrogenated Castor Oil Laurate, Hydrogenated Coconut Oil, Hydrogenated Cottonseed Oil, Hydrogenated C12-C18 Triglycerides, Hydrogenated Fish Oil, Hydrogenated Lard, Hydrogenated Herring Oil, Hydrogenated Mink Oil, Hydrogenated Deep-Sea Fish Oil, Hydrogenated Palm Kernel Oil, Hydrogenated Palm Oil, Hydrogenated Peanut Oil, Hydrogenated Shark Liver Oil, Hydrogenated Soybean Oil, Hydrogenated Butter, Hydrogenated Vegetable Oils, Lanolin and Lanolin Derivatives, Lanolin Alcohol, Porcine Oils, lauric acid / palmitic acid / oleic acid triglycerides, Resclero oil, maleic acid soybean oil, meadowfoam seed oil, cow hoof oil, oleic acid / linoleic acid triglycerides, oleic acid / palmitic acid / lauric acid / myristic acid / linoleic acid triglycerides, stearin, olive shell oil, omentum lipids, deep-sea fish oil, Cibotium barometz oil, lard oil, phospholipids, pistachio oil, placental lipids, rapeseed oil, rice bran oil, shark liver oil, shea butter, sphingolipids, tallow, glycerin triglycerides Hesperidates, triglycerides, tricaprylates, tricaprylates, tricaprylates, tricaprylates, trihydroxymethoxystearin, trihydroxystearin, trisisonononate, triisostearin, trilaurate, triglycerides, trilinoleate, trilinolein, trilinolenic acid, trimyristate, tricaprylate, trioleate, tripalmitate, tricaprylate, tristearate, heptanecanyl alcohol, vegetable oils, wheat bran lipids, and mixtures thereof. Suitable carriers include caprylic / capric triglycerides. This material is currently available, for example, as MYRITOL 318, a product of BASF Corporation (Florham Park, New Jersey, USA) and / or BASF SE (Ludwigshafen, Germany).

[0098] Other suitable carriers may include monoglycerides or diglycerides, such as those derived from saturated or unsaturated, straight-chain or branched, substituted or unsubstituted fatty acids or mixtures of fatty acids. Examples of monoglycerides or diglycerides include mono- or di-C12-24 fatty acid glycerides, specifically mono- or di-C16-20 fatty acid glycerides, such as glyceryl monostearate and glyceryl distearate.

[0099] The carrier may also include esters of straight-chain C6-C22 fatty acids and branched-chain alcohols.

[0100] The carriers envisioned herein may also include sterols, phytosterols, and sterol derivatives. Sterols and sterol derivatives that can be used in the anti-adhesives of this invention include, but are not limited to: β-sterols having a tail at position 17 and lacking a polar group, such as cholesterol, sitosterol, stigmasterol, and ergosterol; and C10-C30 cholesterol / lanosterol esters, cholecalciferol, cholesterol hydroxystearate, cholesterol isostearate, cholesterol stearate, 7-dehydrocholesterol, dihydrocholesterol, dihydrocholesterol octyldecanoate, dihydrolanosterol, octyldecanoate dihydrolanosterol ester, calciferol, tall oil sterol, stigmasterol acetate, lanosterol, stigmasterol, avocadosterol, "AVOCADIN" (trade name of Croda Ltd of Parsippany, NJ), sterol esters, and similar compounds, as well as mixtures thereof. A commercially available example of phytosterols is refined soybean sterol 122 N PRL from Cognis Corporation of Cincinnati, Ohio.

[0101] Fluid Management Layer

[0102] The fluid management layer increases the thickness of absorbent articles and is typically compressible and resilient, which imparts a soft and / or “cushioned” feel to the article. The absorbent articles envisioned herein exhibit good resilience properties under both dry and wet conditions. The fluid management layer described herein comprises nonwoven fibers, cellulose fibers, and bonded fibers, with a thickness factor (mm / 10 gsm basis weight) of approximately 0.26 to approximately 0.35. The fibers have a denier of less than approximately 2.

[0103] The fluid management layer may comprise a nonwoven fabric with a basis weight of approximately 40 gsm to approximately 75 gsm. The fluid management layer may have any suitable shape, including but not limited to elliptical, stadium-shaped, rectangular, asymmetrical, peanut-shaped, trapezoidal, circular trapezoidal, oval, nested, and hourglass shapes. In some examples, the fluid management layer may have a profile shape, for example, a profile shape that is narrower in the longitudinal middle region than in the end regions. In other examples, the fluid management layer may have a tapered shape, which is wider in one end region of the pad and gradually tapers to a narrower width in the other end region of the pad. The fluid management layer may have an elongated elliptical shape. The fluid management layer may have a nested shape, with one end concave and the other end convex.

[0104] In addition to the benefits of softness and resilience of the compositions and structures used in the fluid management layer envisioned herein, stain size control and faster fluid collection are also achieved. Stain size is important in how absorbent articles are perceived by the user. For feminine panty liners, when the stains visible on the panty liner after a period of use / wearing are relatively large along the xy direction, the user may perceive that the panty liner is nearing failure based on the appearance of the stain and its proximity to the outer periphery of the panty liner. In contrast, smaller, lighter stains can have a reassuring effect on the user / wearer by creating the feeling that the panty liner is not nearing failure, because the edges of the stain are substantially longitudinal and / or lateral to the outer periphery of the panty liner.

[0105] The fluid collection speed of a panty liner can be considered important to the user / wearer, as rapid collection helps the user / wearer feel dry and clean. When a panty liner takes a relatively long time to expel the fluid from the top sheet, it can cause the user to feel damp and unclean.

[0106] To enable rapid collection / absorption of discharged fluid, and to provide sufficient capillary action for dehydration of the top plate, the fluid management layer has a specific pore volume range. The fluid management layer may have an average pore size of approximately 90 µm to approximately 330 µm, or alternatively, an average pore size of approximately 100 µm to approximately 150 µm.

[0107] The fluid management layer can draw fluid across and away from the top plate via capillary action or wicking, the magnitude of which is sufficient to overcome any resistance to the fluid passing through the top plate, or any attractive force the top plate may have on the fluid. These forces may be a result of the composition and / or configuration of the top plate. The fluid management layer can also receive and contain fluid outflows by providing orifice volumes as temporary reservoirs and distribution functions, thereby effectively utilizing the absorption structure and giving it time to receive and absorb the fluid.

[0108] The inventors have discovered that, in order to provide the desired level of softness and resilience, combined with the need for rapid acquisition and high capillary action, a fluid management layer breaks through the limitations of past technologies. The fluid management layer of this invention provides high thickness, thus possessing both resilience and flexibility, while also exhibiting high capillary action and permeability.

[0109] In general, the fluid management layer of this disclosure may comprise about 15% to about 35% by weight, about 20% to about 35% by weight, or about 25% to about 35% by weight of cellulose, specifically including cellulose fibers within these ranges and any values ​​within any range therefrom. In a specific example, the fluid management layer may comprise about 30% by weight of cellulose fibers. Suitable cellulose fibers include cotton, rayon, viscose, lyocell, natural cellulose, regenerated cellulose, and combinations thereof. Particularly suitable cellulose fibers include viscose. The cellulose fibers have a denier of less than about 2; alternatively, from about 0.5 to about 1.7.

[0110] The cellulose fibers of the fluid management layer can have any suitable cross-sectional shape (where, when the fiber is straight, the cross section extends along a plane perpendicular to the larger length dimension of the fiber). Examples of some suitable shapes may include trefoil, “H”, “Y”, “X”, “T”, circular, or flat ribbon shapes. Furthermore, the absorbent fibers may have a solid, hollow, or multi-hollow cross section. Other examples of suitable multi-lobed cellulose fibers for use in the fluid management layer described herein are disclosed in US 6,333,108; US 5,634,914; and US 5,458,835. The trefoil fiber shape improves wicking and enhances opacity and stain-concealing properties. Suitable trefoil rayon fibers are available from Kelheim Fibres GmbH (Kelheim, Germany) and are sold under the trade name GALAXY. While individual layers may include absorbent fibers of different shapes (very much like those described above), not all carding equipment is suitable for handling such variations between two or more layers. In one specific example, the fluid management layer may include cellulose fibers having a round shape.

[0111] Cellulose fibers can contain any suitable absorbent material. Suitable absorbent fiber materials include cotton, cellulose (e.g., wood) pulp, regenerated cellulose (rayon, viscose, lyocell, etc.), or combinations thereof. In one example, the fluid management layer may contain viscose fibers.

[0112] The short length of cellulose fibers can be selected from about 20 mm to 100 mm, or 30 mm to 50 mm, or even 35 mm to 45 mm, with all values ​​within these ranges and any ranges arising therefrom listed specifically. Generally, wood pulp fibers are about 4 mm to 6 mm long and are too short for use in conventional carding machines. Therefore, if wood pulp is desired as fibers in the fluid management layer, it may be beneficial to blend the pulp and add it to the carding web as an additional treatment. In some examples, the pulp can be air-formed between the carding webs and then integrated into the composite. As another example, tissue paper made from pulp can be used in combination with a carding web, and this combination can then be integrated.

[0113] Similarly, in general, the fluid management layer of this disclosure may comprise about 65% to about 85% by weight of bonding fibers, specifically listing all values ​​within these ranges and any ranges arising therefrom. Suitable bonding fibers include bicomponent polyethylene terephthalate / polyethylene, combinations of polyethylene, polypropylene, and polyethylene terephthalate, copolymers of polyethylene terephthalate, and combinations thereof. The bonding fiber may be polyethylene terephthalate / polyethylene, wherein the core is polyethylene terephthalate and the sheath is polyethylene. The bonding fiber may include bicomponent fibers. Particularly suitable bonding fibers may include polymer fibers. The bonding fiber may have a denier of less than about 2, alternatively about 1 to about 2. The bonding fiber enhances the fluid management layer's ability to recover its shape and / or thickness after compressive loads applied during use.

[0114] Furthermore, the fluid management layer of this disclosure may also include separator fibers comprising about 35% to about 55% by weight of the fluid management layer. Suitable separator fibers include polypropylene, polyethylene terephthalate, bicomponent polyethylene, bicomponent polypropylene, bicomponent polyethylene terephthalate, and combinations thereof. Suitable separator fibers have a denier of less than about 2, alternatively about 0.5 to about 2. Particularly suitable separator fibers may include non-cylindrical polymer fibers, including but not limited to polypropylene. The separator fibers are used to separate the space between the bonding fibers and the cellulose fibers, thereby creating a smaller pore size that drives capillary action. Small size and optional non-cylindrical shape further achieve this.

[0115] Cellulose fibers, bonding fibers, and / or separating fibers may have lengths of about 10 mm to about 120 mm, alternatively about 24 mm to about 95 mm, and alternatively about 36 mm to about 75 mm. Fiber lengths may be selected from the same length, different lengths, or combinations thereof.

[0116] The weight fractions of cellulose fibers, binder fibers, and / or separator fibers can be determined using the material composition analysis methods disclosed below.

[0117] To provide the required nonwoven thickness and the necessary pore structure for fluid properties, low-density fibers, as previously disclosed, must be utilized. It is also important to employ methods that impart strength to the material in both the MD and CD directions. This is particularly challenging because inappropriate fiber integration will cause the entire material thickness to collapse, especially given the very low fiber density. The fluid management layer comprises integrated stitches with a stitch density between 90 and 220 pinholes / cm². The stitch orientation is selected from top, bottom, and combinations thereof. Furthermore, the fluid management layer has an MD:CD fiber orientation of approximately 1:1 to approximately 1:1.75.

[0118] The fluid management layer may have a peak MD load of about 4 to about 85 Newtons and a peak CD load of about 4 to about 130 Newtons.

[0119] The fiber length of the fluid management system can be from about 10 mm to about 120 mm, alternatively from about 24 mm to about 95 mm, and alternatively from about 36 mm to about 75 mm. The fiber length can be selected from the same length, different lengths, or combinations of lengths.

[0120] The inventors have discovered that the material can be cross-lapped and integrated using specially designed needles. This provides the desired MD and CD material tensile (reported as peak load) and MD / CD tensile ratio while maintaining the overall material thickness because the energy of the entanglement is concentrated on individual fibers rather than the entire fiber web. Figure 3 The diagram shows a non-overlapping fluid management layer. Figure 4 This shows a cross-overflowing fluid management layer. Figure 4 In this structure, the fibers are oriented in both the MD and CD directions.

[0121] Needle punching redirects fibers from the xy-plane to the z-direction to produce concentrated fiber bundles oriented in the z-direction (e.g., Figure 5 (As shown). Vertical bundles create a path for fluid to flow efficiently through the material in the z-direction to reach the core more quickly, especially in surge conditions. Vertical fiber bundles 400 also increase elasticity and compressibility in the z-direction.

[0122] To further improve the drying capability of the fluid management layer, the fluid management layer may have small, highly concentrated fiber regions distributed throughout the entire fluid management layer. These small, highly concentrated fiber regions, or capillary reinforcement points 500, 502, can... Figure 6As seen in the image, capillary reinforcement points exhibit high capillary activity, but because they spread over a wide area, they have minimal or no impact on overall permeability, and therefore minimal or no impact on the top sheet collection rate. These capillary reinforcement points can be spaced apart in various ways. For example, there can be approximately 1 to approximately 10 capillary reinforcement points per square inch; alternatively, approximately 3 to approximately 7 capillary reinforcement points per square inch. Capillary reinforcement points can be easily observed optically, especially using a stage in which the number of points is counted within a square inch of the material. The size of the capillary reinforcement points can vary between approximately 0.5 mm² and approximately 5 mm². The generation of capillary reinforcement points is controlled by carefully calibrating the speed within the carding unit and the needle punching speed, combined with the small fraction fiber selection described herein.

[0123] The nonwoven fabric of the present invention is initially a blend, stack, and lay-up of fibers, fed through one or more carding steps. Then, prior to the fiber web forming process, the nonwoven material is cross-lapped. Cross-lapping is well known to those skilled in the art. For example, when laid on a belt or carrier, the carded fiber web material moves forward and backward while pulling its lower front portion perpendicular to this forward and backward movement, thereby causing the fiber web material to overlap in a Z-shape. This imparts a sufficient MD / CD draw ratio.

[0124] The nonwoven fabric is then needle-punched using one or more knitting machines. Here, a loose fiber web, such as a carded fiber web, is transformed into a coherent nonwoven fabric. The needle-punched fibers are mechanically oriented through the fiber web. The needles can be arranged in a non-linear configuration on a needle tool (e.g., a needle plate or a loom). During the needle-punching step, at least one needle tool can be used in the range of about 50 to 250 needles per square inch, alternatively about 70 to 200 needles per square inch, and alternatively about 90 to 180 needles per square inch.

[0125] Then, after needle-punching the fluid management layer material, the nonwoven fabric is bonded via heat treatment. This bonding of the bonding fibers creates a supporting matrix that enhances the resilience and stiffness of the fluid management layer.

[0126] This paper envisions absorbent articles exhibiting a soft, cushioned feel, good resilience, and fluid handling properties. To impart these properties, the thickness of the fluid management layer can be considered important. Typical thicknesses of fiber webs from conventional hydrospunlace yarns achieve a thickness factor (thickness / 10 gsm basis weight) of 0.03 to 0.12. In contrast, the fluid management layer envisioned in this paper could exhibit a thickness factor of at least 0.26. The fluid management layer envisioned in this paper could have a thickness factor between 0.26 and approximately 0.35, including all values ​​within these ranges and any ranges arising therefrom. It is important to note that the thickness factor, as previously stated, refers to the thickness obtained using the thickness measurement method described below.

[0127] During thermal bonding, the choice of heating temperature can be influenced in part by the composition of the reinforcing fibers, the design and operating parameters of the heating equipment, and the processing speed of the fiber web (i.e., the duration of exposure to the thermal environment). To impart uniform stiffness across the entire fluid management layer, the heating equipment and operating parameters should be configured to provide uniform heating to the fiber web in the fluid management layer. Even small temperature variations can significantly affect the formation of fiber-to-fiber bonds between the bonding fibers and the resulting tensile strength of the fluid management layer. An example of a suitable thermal strengthening method is air-to-heating, where air heated to the selected heating temperature is blown and / or evacuated (via vacuum) through the fiber web in a direction substantially orthogonal to the larger plane defined by the fiber web. A suitable MD / CD peak load ratio is in the range of approximately 0.5 to 1.75.

[0128] The fluid management layer envisioned in this paper can be incorporated into various absorbent articles. Figure 1 The diagram illustrates a schematic, non-limiting example of an absorbent article in the form of a feminine sanitary pad, as contemplated herein. As reflected, the pad 10 contemplated herein may include a top sheet 20, a back sheet 50, and an absorbent structure 40 disposed between the top sheet 20 and the back sheet 50. A fluid management layer 30 may be disposed between the top sheet 20 and the absorbent structure 40. The pad has a wearer-facing surface 62 and an opposing outward-facing surface 64. The wearer-facing surface 62 is formed primarily of the top sheet 20, while the outward-facing surface 64 is formed primarily of the back sheet 50. Additional components (not shown) may be included adjacent to the wearer-facing surface 62 and / or the outward-facing surface 64. For example, if the absorbent article is an incontinence pad, a pair of barrier bands extending generally parallel to the longitudinal axis of the pad 10 may also form part of the wearer-facing surface 62. Similarly, one or more deposit-fixing adhesives (to be used by the user / wearer to attach the pad in place within her underwear for use) may be present on the back sheet 50 and form part of the outward-facing surface 64 of the absorbent article.

[0129] Thickness coefficient

[0130] Unlike conventional spunlace materials, the fluid management layer can have a thickness factor of at least about 0.26 (mm thickness / 10gsm). The fluid management layer 30 can have a thickness factor between 0.26 and about 0.35, including all values ​​within these ranges and any ranges arising therefrom. The thickness and thickness factor of the fluid management layer of this disclosure can be determined by the thickness and thickness factor testing methods disclosed herein.

[0131] Basis weight

[0132] The fluid management layer may have a basis weight of up to 75 g / m² (gsm); or up to 70 gsm; or a basis weight in the range of about 40 gsm to about 75 gsm; or a basis weight in the range of about 50 gsm to about 70 gsm; or a basis weight in the range of about 55 gsm to about 65 gsm, including any value within these ranges and any ranges arising therefrom. In another specific example, the fluid management layer 30 may have a basis weight of 40 gsm to 60 gsm.

[0133] fiber

[0134] To enhance the stabilizing effect of integration, crimped fibers can be utilized. As discussed in further detail below, the fluid management layer of this disclosure may comprise cellulose fibers, bonding fibers, and additionally, separating fibers. One or more of these fibers may be crimped prior to integration. For example, in the case of synthetic fibers, these fibers may be mechanically crimped by interlocking teeth. And for cellulose fibers, these fibers may be mechanically crimped and / or may have chemically induced crimping due to the variable surface thickness formed during the production of the cellulose fibers.

[0135] Absorption structure

[0136] The absorbent structure 40 of this disclosure can have any suitable shape, including but not limited to elliptical, stadium-shaped, rectangular, asymmetrical, peanut-shaped, trapezoidal, circular trapezoidal, oval, nested, and hourglass-shaped. In some examples, the absorbent structure 40 can have a contour shape, for example, it is narrower in the longitudinal middle region than in the end regions. In other examples, the absorbent structure can have a tapered shape, which is wider in one end region of the pad and gradually tapers to a narrower width in the other end region of the pad. The absorbent structure can have a nested shape, with one end concave and the other end convex. The absorbent structure 40 can have different stiffnesses in the longitudinal and transverse directions.

[0137] The configuration and construction of the absorbent structure 40 can be varied (e.g., the absorbent structure 40 may have different thickness zones, hydrophilic gradients, superabsorbent gradients, or lower average density and lower average basis weight collection zones). Additionally, the size and absorbency of the absorbent structure 40 can be varied to accommodate a variety of wearers. However, the total absorbency of the absorbent structure 40 should meet the design load and intended use of the disposable absorbent article or incontinence pad 10.

[0138] In some examples, the absorbent structure 40 may include multiple layers, each having specific features and / or functions. In some examples, the absorbent structure 40 may include an encapsulation (not shown) that includes absorbent components encapsulating the absorbent structure. The encapsulation may be formed of one or more nonwoven materials, tissue paper, films, or other materials or laminates thereof. In one form, the encapsulation may be formed solely of a single material, substrate, laminate, or other material that at least partially surrounds itself.

[0139] The absorbent structure 40 may include one or more adhesives, for example, to help fix SAP or other absorbent materials into the first and second layers.

[0140] Suitable absorbent structures with various core designs containing relatively high amounts of superabsorbent polymers (“SAP” – also known as “absorbent gelling materials” or “AGM”) are disclosed in US 5,599,335; EP 1,447,066; WO 95 / 11652; US 2008 / 0312622 A1; and WO 2012 / 052172.

[0141] Additions to the absorber structure have been envisioned. Potential additions to the absorber structure are described in US 4,610,678, US 4,673,402, US 4,888,231, and US 4,834,735. The absorber structure may also include a layer simulating a dual-core system comprising a collection / dispensing core of chemically hardened fibers positioned above the absorber storage core, as described in US 5,234,423; and US 5,147,345. These may be considered useful as long as they do not counteract or conflict with the function of the laminates described below in the absorber structure of the present invention.

[0142] Further examples of suitable absorbent structures 40 that can be used in absorbent articles of this disclosure are described in US2018 / 0098893 and US2018 / 0098891.

[0143] As described above, the absorbent article envisioned herein, which includes a fluid management layer, may include a storage layer. See again Figure 1 A and Figure 1B. The storage layer will generally be positioned corresponding to the location depicted in the absorbent structure 40. The storage layer may be constructed as described with respect to the absorbent structure. The storage layer may contain conventional absorbent materials. In addition to conventional absorbent materials such as crepe cellulose filler, fluff cellulose fibers, rayon or viscose fibers and pulverized wood pulp fibers (also known as breathable felt or fluff pulp) and textile fibers, the storage layer may also include particles or fibers of a superabsorbent material that receives fluids and forms a hydrogel. (Such materials are also known as absorbent gelling materials (AGM).) AGMs are typically capable of absorbing relatively large weights of body fluid / dry weight AGM and maintaining them under moderate pressure. Synthetic fibers spun from polymers, such as cellulose acetate, polyvinylidene fluoride, polyvinylidene chloride, acrylic resins (such as oron), polyvinyl acetate, insoluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon), polyester, bicomponent fibers, tricomponent fibers, mixtures thereof, etc., may also be included in the second storage layer. The storage layer may also include filler materials such as perlite, diatomaceous earth, vermiculite, or other suitable materials that can help reduce backflow variations.

[0144] The storage layer or fluid storage layer may comprise an absorbent gelling material (AGM) that is uniformly distributed throughout, or it may comprise an absorbent gelling material that is non-uniformly distributed. The AGM may be distributed and / or concentrated by depositing it into channels or pockets, or it may be deposited in a pattern, including stripes, cross patterns, swirls, dots, or any other conceivable two-dimensional or three-dimensional pattern. The AGM may be sandwiched between a pair of fiber capping layers. The AGM may be at least partially encapsulated by a single fiber capping layer.

[0145] Part of the storage layer may be formed essentially solely of superabsorbent material / AGM, or may be formed of AGM distributed and dispersed in aggregates of cotton or cellulose fibers in the form of fluff or reinforcing fibers. A non-limiting example of the storage layer may include a first layer formed essentially solely of AGM particles or fibers, which are placed or deposited onto a second layer formed by the distribution of AGM particles or fibers within the cellulose fibers.

[0146] Examples of absorbent structures formed by superabsorbent material / AGM layers and / or other aggregates dispersed within cotton fibers or cellulose fibers, which can be used in absorbent articles (e.g., sanitary napkins, incontinence products) envisioned herein, are disclosed in US 2010 / 0228209A1. Absorbent structures employing various core designs, including those with relatively high SAP / AGM contents, are disclosed in the following patents: US 5,599,335, EP 1 447 066, WO 95 / 11652, US.2008 / 0312622 A1; WO2012 / 052172; US 8,466,336; and US 9,693,910 granted to Carlucci. These can be used to construct absorbent structures or storage layers.

[0147] negative

[0148] The substrate 50 may be disposed beneath the absorbent structure 40 and be the outermost layer of the article, thereby forming the outward-facing surface of the article. The substrate 50 may be bonded to the absorbent structure 40 and / or the top sheet (around the outer perimeter) by any suitable attachment method known in the art. For example, the substrate 50 may be secured to the absorbent structure 40 by a uniform, continuous layer of adhesive, a patterned layer of adhesive, or a series of separate adhesive lines, spirals, or dots. Alternatively, the attachment method may include the use of thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other suitable attachment method or combination of these methods known in the art.

[0149] The film may be impermeable or substantially impermeable to liquids (e.g., urine, menstrual fluid) under normal use conditions and may be made of a thin plastic film, but other flexible, liquid-impermeable materials may also be used. The film prevents or at least inhibits the absorption and containment of effluents within the absorbent structure from wetting underwear, outerwear, bedding, etc., that may come into contact with or be adjacent to the article. However, in some examples, the film may be configured to allow vapors to escape from the absorbent structure (i.e., “breathable”), while in others, the film may be configured to be vapor-impermeable (i.e., impermeable). The film may comprise a polymer film, such as a polyethylene film or a polypropylene film. For example, a suitable material for the film is a thermoplastic film having a thickness of about 0.012 mm (0.5 mils) to 0.051 mm (2.0 mils). Suitable materials for the film film may have a basis weight of about 8 gsm to about 25 gsm. Any suitable liquid-impermeable film known in the art may be used in this invention.

[0150] The pad acts as a barrier to prevent fluids absorbed and retained in the absorbent structure from migrating to the outward-facing surface of the pad. Suitable materials are soft, smooth, and permeable to liquids and vapors, providing comfortable softness and conformability, and producing low noise to avoid annoying noise during movement.

[0151] Non-limiting examples of materials suitable for forming film are described in US 5,885,265, US 6,462,251, US 6,623,464, and US 6,664,439. Examples of suitable double or multilayer breathable films include those described in US 3,881,489, US 4,341,216, US 4,713,068, US 4,818,600, EP 203 821, EP 710 471, EP 710 472, and EP 793952. Additional examples of suitable single-layer breathable films include those described in GB A 2184 389, GB A 2184 390, GB A 2184 391, US 4,591,523, US 3,989 867, US 3,156,242 and WO 97 / 24097.

[0152] The substrate can be a nonwoven fiber web having a basis weight of about 20 gsm to 50 gsm. In one example, the substrate can be a spunbond nonwoven fiber web of 23 gsm hydrophobic 4 denier polypropylene fibers, which can be purchased from Fiberweb Neuberger under the trade name F102301001. As described in US 6,436,508, the substrate can be coated with an insoluble liquid expandable material.

[0153] The backing has an outward-facing side and an opposite, wearer-facing side. The outward-facing side of the backing may include non-adhesive and adhesive areas. To allow the user / wearer to attach the pad to the wearer-facing surface of her underwear in a suitable position, the adhesive area can be provided by any conventional means. Pressure-sensitive adhesives have been found to be very suitable for this application.

[0154] Traditional absorbent fabrics extend the core as far as possible across the crotch area to capture fluid that might escape to the edges. This can result in an uncomfortable experience for the wearer. Other traditional absorbent fabrics narrow the core to improve comfort and attempt to extend the fluid management layer into a wider area of ​​the crotch, but this does not produce the necessary distance or shape change required for optimal performance.

[0155] An additional technical feature of the absorbent article described herein is a stepped side barrier sufficient to trap fluid that may escape to the edges of the absorbent article. The disposable absorbent article includes a top sheet, a bottom sheet, an absorbent core disposed between the top sheet and the bottom sheet, and a fluid management layer disposed between the top sheet and the absorbent core. The fluid management layer described herein has a basis weight of approximately 40 gsm to approximately 75 gsm and is bonded to the top sheet in the process to create a differential tension composite fiber web. This allows the top sheet to fully conform to the side edges of the fluid management layer and subsequently bond to the bottom sheet, while retaining the morphological characteristics of the fluid management layer at the edges of the fluid management layer in the crotch area. The fluid management layer is wider than the edges of the absorbent core in the crotch area, resulting in a flexible and comfortable product while retaining a minimum step change of approximately 1.5 mm in the crotch area. A suitable range of step change is approximately 1.8 mm to approximately 3.5 mm.

[0156] Test methods

[0157] Pore ​​volume distribution test method

[0158] The pore volume distribution test method is used to determine the average absorption pressure, average desorption pressure, and average pore size of a porous test sample by measuring the associated fluid movement into and out of the sample when a stepped controlled pressure difference is applied to the sample in the test sample chamber.

[0159] Method Principles

[0160] For a uniform cylindrical hole, the radius of the hole is related to the pressure differential required to fill or empty the hole using the following formula.

[0161] Pressure difference = (2γ cos Θ) / r,

[0162] Where γ = liquid surface tension, Θ = contact angle, and r = pore radius.

[0163] The pores contained in natural and artificial porous materials are generally referred to by terms such as voids, pores, or conduits, and these pores are typically neither perfectly cylindrical nor perfectly homogeneous. However, the above formula can be used to correlate pressure differential with effective pore radius, and the distribution of effective pore radius in porous materials can be characterized by monitoring the change in liquid flow into or out of the material with pressure differential. (Because using effective pore radius approximates non-uniform pores as uniform pores, the results produced by this general method may not be precisely consistent with measurements of pore size obtained by other methods, such as microscopy.)

[0164] The pore volume distribution testing method utilizes the principles described above and applies this method in practice using the equipment and methods described by B. Miller and I. Tyomkin in “Liquid Porosimetry: New Methodology and Applications”, published in The Journal of Colloid and Interface Science (1994), Vol. 162, pp. 163–170, which is incorporated herein by reference. This method relies on measuring the increment of liquid volume flowing into or out of the porous material, as the air pressure difference (positive differential pressure) varies between the ambient (“laboratory”) air pressure and the slightly elevated air pressure surrounding the sample in the sample test chamber. The sample is introduced into a dry sample chamber, and the sample chamber is maintained at a positive differential pressure (relative to the laboratory) sufficient to prevent fluid from being drawn into the sample after the fluid bridge is opened. After the fluid bridge is opened, the air differential pressure is reduced to 0 in the step, and during this process, subgroups of pores collect liquid according to their effective pore radii. After reaching a minimum differential pressure where the fluid mass within the sample is at its maximum, the differential pressure is gradually increased again towards the initial pressure, and liquid is expelled from the sample. During the subsequent discharge sequence (from minimum differential pressure or maximum corresponding effective orifice radius to maximum differential pressure or minimum corresponding effective orifice radius), the fluid retention (g / g) of the sample at each differential pressure is determined in this method. After correcting for any fluid movement measured in the empty chamber for each specific pressure step, the sample fluid retention (g / g) for each pressure step is determined by dividing the equilibrium amount (g) of the retaining liquid associated with that specific step by the dry weight (g) of the sample.

[0165] Sample conditioning and specimen preparation

[0166] A pore volume distribution test method was performed on samples conditioned in an indoor environment at 23°C ± 2.0°C and 50% ± 5% relative humidity. All tests were conducted under the same environmental conditions and in such a conditioning chamber. Any damaged products or samples with defects such as wrinkles, tears, or pores were not tested. For the purposes of this invention, samples conditioned as described herein are considered dry samples. Three specimens were measured for any given test material, and the results from those three replicate specimens were averaged to give a final reported value. Each of the three replicate specimens had a diameter of 50 mm. The dry mass of each prepared test specimen was recorded to an accuracy of 0.001 g.

[0167] equipment

[0168] The apparatus suitable for this method is described in “Liquid Porosimetry: New Methodology and Applications” by B. Miller and I. Tyomkin in The Journal of Colloid and Interface Science (1994), Vol. 162, pp. 163–170. Furthermore, any pressure control scheme capable of maintaining the sample chamber pressure between a pressure difference of 0 mm H₂O and 1200 mm H₂O can be used instead of the pressure control subsystem described in this reference. An example of suitable overall instrumentation and software is the TRI / Automatic Pore Analyzer (Textile Research Institute (TRI) / Princeton Inc (Princeton, NJ, USA)). The TRI / Automatic Pore Analyzer is an automated, computer-controlled instrument for determining the pore volume distribution in porous materials (e.g., the volume of pores of different sizes within an effective pore radius range of 1 µm to 1000 µm). Computer programs such as Automated Instrumentation Software version 2000.1 or 2003.1 / 2005.1 or 2006.2; or Data Processing Software version 2000.1 (available from TRI Princeton Inc.), and spreadsheet programs are available for capturing and analyzing the measured data.

[0169] Methods and Procedures

[0170] The wetting liquid used was degassed hexadecane (CAS 544-76-3, reagent grade, available from any convenient source). The liquid density was 0.773 g / cm³. 3 The surface tension γ is 27±1mN / m, and the contact angle cos Θ=1. A 90-mm diameter mixed-cellulose-ester filter membrane with a characteristic pore size of 1.2μm (such as a membrane from Millipore Corporation (Bedford, MA), catalog number #RAWP09025) is attached to a porous glass flotation (Monel plate, 90mm in diameter and 6.4mm thick, from Mott Corp. (Farmington, CT), or equivalent) in the sample chamber.

[0171] Those skilled in the art understand that degassing the test fluid and the glass frit / film / tube system is crucial to making the system free of air bubbles.

[0172] A 414g metal weight was placed on top of the sample to apply a constant confining pressure of 2.068kPa during the measurement.

[0173] The pressure differentials (in mm H2O) during the test were performed in the following order: 1100, 550, 367, 275, 220, 183, 138, 110, 92, 79, 69, 61, 55, 50, 46, 42, 39, 37, 34, 32, 31, 29, 28, 24, 22, 20, 18, 14, 9, 7, 6, 5, 4.5, 0, 4.5, 5, 6, 7, 9, 14, 18, 20, 22, 24, 28, 29, 31, 32, 34, 37, 39, 42, 46, 50, 55, 61, 69, 79, 92, 110, 138, 183, 220, 275, 367, 550, 1100.

[0174] The criterion for moving from one pressure step to the next is that the fluid absorption / discharge measured by the sample is less than 10 mg / min, lasting for 15 seconds.

[0175] By following this methodological procedure with an empty sample chamber, separate "blank" measurements are performed in the absence of a sample or weight on the membrane / glass frit assembly. Any observed fluid movement (g) is recorded at each pressure step. The fluid retention data for the sample is calibrated for any fluid movement associated with the empty sample chamber by subtracting the fluid retention value of this "blank" measurement from the corresponding value in the sample measurement.

[0176] Determination of average absorption pressure, average desorption pressure, and average pore size

[0177] As described above, for any effect of the empty chamber, the capillary fluid (g) absorbed by the test sample during the fill cycle (absorption) of each pressure step of the pressure differential is corrected, and then divided by the dry mass of the sample to obtain the capillary fluid uptake normalized to the dry sample mass, recorded to an accuracy of 0.001 g / g. Similarly, for any effect of the empty chamber, the capillary fluid (g) retained by the test sample during the drain cycle of each pressure step of the pressure differential is corrected, and then divided by the dry mass of the sample to obtain the capillary fluid discharge normalized to the dry mass, recorded to an accuracy of 0.001 g / g. At the lowest pressure differential, the test sample is considered 100% saturated, and at this pressure step, the normalized uptake is at its maximum. The saturation percentage for each pressure step of the pressure differential is calculated by dividing the normalized uptake of each pressure step by the maximum normalized uptake, and then dividing by 100. For the fill cycle (absorption), the pressure differential value at 50% saturation is recorded as the mean absorbed pressure (MAP), accurate to 0.01 cm H₂O. For the drainage cycle, the pressure difference at 50% saturation is recorded as the mean desorption pressure (MDP), accurate to 0.01 cm H2O.

[0178] The effective orifice radius R under each pressure step of the pressure differential is calculated using the following formula and recorded to an accuracy of 0.01 micrometers.

[0179] pressure difference i = (2 γ cos Θ) / R i

[0180] Where γ = liquid surface tension, Θ = contact angle, and r = pore radius.

[0181] Calculate the fluid volume associated with each effective orifice radius V using the following formula, and record the value accurate to 0.01 mm. 3 / g / micrometer.

[0182]

[0183] Where w i For the fluid absorbed (or retained, g) at pressure i (corrected for any effects of the cavity), d = fluid density (0.773 g / cm³). 3 ), R i = The pore radius (micrometers) under pressure i and w 样品 =Mass of the dry sample (g).

[0184] The average pore size of the test specimen used for filling the cycle (absorption) is calculated using the following formula, which is a weighted average of the pore size based on the volume of the fluid, using the radius (R) and volume (V) values ​​from the filling cycle (absorption).

[0185]

[0186] Where W = weighted average of aperture size, n = number of items to be averaged, w i =The volume of the fluid V, and X i =Effective pore radius R. Record the average pore diameter of the absorber, accurate to 0.1 micrometers.

[0187] Similarly, using the same formula, the average pore size of the test specimen used for the drainage cycle is calculated using the radius and volume values ​​from the drainage cycle. The average pore size of the drainage is recorded to an accuracy of 0.1 micrometers.

[0188] The procedure was repeated for a total of three replicate test specimens in a similar manner. The arithmetic mean of the three values ​​for each recorded parameter (MAP, MDP, average pore size of absorption, and average pore size of drainage) was reported.

[0189] Time to collect and resuspension method (ATRM)

[0190] This method describes how to measure the ebb-out collection time, interfacial free fluid volume, and low- and high-pressure rewetting values ​​of an absorbent article loaded with nascent artificial efflorescence fluid (nAMF; a preparation provided separately herein). Following a pretreatment step, a known volume of nAMF is introduced into the absorbent article three times. The time required for each nAMF dose to be collected from the absorbent article is measured using a permeation plate and an electronically timed interval. After each liquid dose, the interfacial free fluid (IFF) is measured by gravimetric analysis as the liquid transfers from the bottom surface of the permeation plate to the filter paper. Low- and high-pressure rewetting are then measured after the final liquid dose. Surface free fluid (SFF) is the amount of fluid retained in the top sheet of the absorbent article. SFF is measured by performing a low-pressure (0.1 psi) rewetting. Immediately after measuring SFF, a higher-pressure (0.5 psi) rewetting is performed to determine the total rewetting of the absorbent article. All tests are performed in a chamber maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0191] See Figures 8 to 11 The permeable plate 9001 is made of resin glass or equivalent with overall dimensions of 10.2 cm long × 10.2 cm wide × 3.1 cm high. The central test fluid well 9008 has a circular opening with a diameter of 25 mm located on the top plane of the plate, which has an initial transverse wall extending 15 mm deep at a 90° angle, then sloping downwards at an additional depth of 7.5 mm at an 82° angle to reach the test fluid reservoir 9003. The test fluid reservoir 9003 is concentric with the test fluid well 9008 and has a diameter of 6.6 mm and a transverse wall extending 5 mm deep at a 90° angle. The test fluid reservoir 9003 leads to a longitudinal fluid channel 9007 located at the bottom of the plate. The longitudinal fluid channel 9007 has transverse walls that initially extend 3.5 mm deep at the midpoint of the channel (just below the test fluid reservoir 9003), then slope downwards at an angle 9007a at 0.72° to a final depth of 3 mm towards each longitudinal end of the channel. The longitudinal fluid channel leads to the bottom plane of the plate for introducing fluid onto the test sample below. The longitudinal fluid channel 9007 is centered on the test fluid reservoir 9003 and extends in a direction perpendicular to the electrode 9004. The longitudinal fluid channel 9007 has a width of 5 mm and a length of 80 mm, with transverse edges rounded to a radius of 1.0 mm (9007b). The longitudinal ends of the longitudinal fluid channel 9007 are rounded with a radius of 2.5 mm (9009). Two wells 9002 (80.5 mm long × 24.5 mm wide × 25 mm deep) located outside the fluid reservoir were filled with stainless steel shot (or equivalent) to adjust the total mass of the plate to provide 0.10 psi (7.0 g / cm³) to the test area. 2The constraint pressure is then described in this document. Electrode 9004 is embedded in plate 9001, and an external banana jack 9006 is connected to the inner wall 9005 of the longitudinal fluid channel 9003. A circuit interval timer is inserted into jack 9006 to monitor the impedance between the two electrodes 9004 and to measure the time from the introduction of nAMF into the reservoir 9003 until nAMF is discharged from the reservoir. The timer has a resolution of 0.01 seconds.

[0192] A pretreatment plate, used in conjunction with pretreatment weights, is used to apply tiny droplets of nAMF to the surface of a test sample as a means of preparing the sample surface before introducing the full liquid dose. The pretreatment plate, constructed of glass resin or equivalent, measures 14 inches (35.6 cm) long × 8 inches (20.3 cm) wide and approximately 0.25 inches (6.4 mm) thick. The plate has five circular markers, each 5 mm in diameter, spaced 1 cm apart (center to center), aligned along the longitudinal axis of the plate. The center marker is centered at the transverse midpoint of the plate. These markers indicate the location of the nAMF droplets. The markers are located on the underside of the pretreatment plate and can be ground off or simply drawn on with permanent markings or equivalents. The pretreatment weights are 10.2 cm × 10.2 cm and are made of a flat, smooth, rigid material (e.g., stainless steel) with optional handles. The pre-treated weights (including the optional handle) have a total mass of 726g + 0.5g, producing 0.10psi (7.0g / cm²) on the bottom surface area of ​​the weights. 2 (The pressure)

[0193] When measuring interfacial fluid volume, a rubber pad is used to provide a reproducible flat surface that enables uniform pressure distribution. The IFF rubber pad is constructed from high-strength neoprene rubber (purchased from W. W. Grainger, Inc., item #1DUV4, or equivalent) with a 40A hardness tester and a thickness of 1 / 8 inch, and cut to a 6-inch (15.2 cm) x 6-inch (15.2 cm) dimension.

[0194] For the total backflow portion of the test, 0.5 psi (35.1 g / cm³) needs to be applied to the test area. 2 The backflow weight assembly is described below. The procedure for determining the test area is then described in this document. The backflow weight is constructed as follows: A sheet of polyethylene film (approximately 25 micrometers thick, from any convenient source) is laid horizontally on a rigid workbench surface. A sheet of polyurethane foam (25 mm thick, density 1.0 lb / ft) is placed on the surface of the workbench. 3A piece of polyurethane foam (IDL 24psi, available from Concord-Renn Co. Cincinnati, OH, or equivalent) was cut into 10.2cm x 10.2cm pieces and placed centered on top of the membrane. A piece of resin glass (10.2cm x 10.2cm and approximately 6.4mm thick) was then stacked on top of the polyurethane foam. Next, the polyurethane foam and resin glass were wrapped with polyethylene film and secured with transparent tape. Metal weights with handles were stacked on top of the resin glass and secured to it, allowing the total mass of the filler weight assembly to be adjusted to apply 0.5psi (35.1g / cm²) to the test area. 2 (The pressure)

[0195] For IFF, SFF, and total backfiltration steps, multiple layers of filter paper are required. Condition the filter paper at 23°C ± 2°C and 50% ± 2% relative humidity for at least 2 hours prior to testing. Suitable filter paper has a basis weight of approximately 88 gsm, a thickness of approximately 249 microns, an absorption rate of approximately 5 seconds, and is available from Ahlstrom-Munksjo (Mt. Holly Springs, PA) at grade 632 or equivalent. The filter paper should be 5 inches × 5 inches (12.7 cm × 12.7 cm).

[0196] Before testing, condition the test samples at 23°C ± 2°C and 50% ± 2% relative humidity for at least 2 hours. Remove the test samples from their outer packaging and, if applicable, open the package to unfold the product, handling it carefully without pressing or pulling on it. Do not attempt to smooth out wrinkles. If applicable, tear off the release paper between the wings and place the sample on a level, flat, rigid surface with the body side up (e.g., underwear side down). Determine the dosing position as follows: For symmetrical products (i.e., when laterally divided along the midpoint of the product's longitudinal axis, the front of the product has the same shape and size as the rear), the dosing position is the intersection of the midpoint of the longitudinal axis and the midpoint of the lateral axis of the absorbent core. For asymmetrical products (i.e., when laterally divided along the midpoint of the product's longitudinal axis, the front of the product does not have the same shape and size as the rear), the dosing position is the midpoint of the product wings at the lateral midpoint of the absorbent core. For products with perforated or printed holes and slits in the foam core, the dosing position is the longitudinal midpoint of the perforated (or printed) area at the transverse midpoint of the absorbent core. Once determined, mark the dosing position with a small dot using a black, fine-tipped, permanent marker. If wings are present, fold them to the back of the product.

[0197] The test area for the test sample is determined as follows. This area will be used to allow for appropriate adjustment of the mass of the permeate plate and the reabsorption weight 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 as the distance between one transverse edge of the core and the other transverse edge of the core along a line extending from the dosing position and perpendicular to the longitudinal axis of the test sample, and recorded as the core width, accurate to 0.01 cm. The core width is now multiplied by 10.2 cm (the length of the permeate plate and the reabsorption weight) and recorded as the test area, accurate to 0.1 cm. 2 The total mass of the permeable board is the test area multiplied by 7 g / cm³. 2 The total mass of the reabsorption weights is the test area multiplied by 35.1 g / cm³. 2 .

[0198] Pretreatment of the test sample with nAMF is performed as follows. Place the pretreatment plate on a horizontal, flat, rigid surface with the side bearing the circular markings facing down. Using a single-channel, fixed-volume pipette, accurately dispense 50 µL of nAMF to each of the five circular markings on the top side of the pretreatment plate. Position the test sample above the pretreatment plate with the body side of the sample facing the plate, the longitudinal axis of the sample and the plate aligned, and the pre-marked dispensing position on the test sample centered above the center droplet of nAMF on the pretreatment plate. After proper positioning, place the test sample in contact with the pretreatment plate and immediately apply the pretreatment weight to the back side of the test sample, centering it above the dispensing position / center droplet of nAMF on the pretreatment plate. Start a 40-second timer. After 40 seconds, remove the pretreatment weight from the test sample and remove the test sample from the pretreatment plate. Invert the test sample so that the body side is facing up, place it on a horizontal, flat, rigid surface, and immediately continue with the following steps.

[0199] The first acquisition time (ACQ-1) is measured as follows. Connect the electronic circuit interval timer to the permeation plate 9001 and zero the timer. Position the permeation plate 9001 above the body side of the test sample, such that the long axis of the longitudinal fluid channel 9007 on the underside of the permeation plate 9001 is aligned with the longitudinal axis of the test sample, and ensure that the fluid reservoir 9003 is centered above the pre-marked dispensing position on the test sample. Note that nAMF should be visible through the fluid reservoir 9003 at the dispensing position on the test sample. After proper positioning, gently place the permeation plate 9001 onto the test sample. Using an adjustable volume pipette, accurately dispense 2.0 mL of nAMF into the fluid well 9008 in the permeation plate 9001. Dispense the fluid along the angled wall of the fluid well 9008 for 3 seconds or less without splashing. Record the first acquisition time (ACQ-1) displayed on the circuit interval timer immediately after the fluid has been collected, accurate to 0.1 seconds. Place the 9001 breathable plate in the appropriate position on the test sample and immediately start the 2-minute timer.

[0200] After 2 minutes, the first interfacial free fluid (IFF-1) was measured as follows. The IFF rubber pad was placed on a horizontal, flat, rigid surface. The mass of one layer of filter paper was measured to an accuracy of 0.0001 g and recorded as IFF-1. 初始 Place the filter paper centered on the IFF rubber pad. Transfer the permeation plate 9001 from the test sample to the pre-weighed filter paper, centering the plate on the filter paper, and immediately start the 8-minute timer. After 10 seconds on the 8-minute timer, remove the permeation plate from the filter paper and gently place it back onto the test sample, precisely as previously positioned. Over the next 10 seconds, measure the mass of the filter paper, accurate to 0.0001 g, and record it as IFF-1. 最终 .

[0201] The second acquisition time (ACQ-2) was measured as follows. After 8 minutes, a second ejaculation of fluid was applied using an adjustable-volume pipette to accurately dispense 4.0 mL of nAMF into fluid well 9008 in the permeation plate 9001, as previously described. The second acquisition time (ACQ-2), accurate to 0.1 seconds, was recorded immediately after fluid collection on the circuit interval timer. The permeation plate 9001 was left in place on the test sample, and the 2-minute timer was started immediately.

[0202] After 2 minutes, the free fluid at the second interface (IFF-2) was measured as follows. The IFF rubber pad was placed on a horizontal, flat, rigid surface. The mass of the fresh monolayer filter paper was measured to an accuracy of 0.0001 g and recorded as IFF-2. 初始Place the filter paper centered on the IFF rubber pad. Transfer the permeation plate 9001 from the test sample to the pre-weighed filter paper, centering the plate on the filter paper, and immediately start the 8-minute timer. After 10 seconds on the 8-minute timer, remove the permeation plate 9001 from the filter paper and gently place it back onto the test sample, precisely as previously positioned. Over the next 10 seconds, measure the mass of the filter paper, accurate to 0.0001 g, and record it as IFF-2. 最终 .

[0203] The third acquisition time (ACQ-3) was measured as follows. After 8 minutes, a third ejaculation of fluid was applied using an adjustable-volume pipette to accurately dispense 2.0 mL of nAMF into fluid well 9008 in the permeation plate 9001, as previously described. The third acquisition time (ACQ-3), accurate to 0.1 seconds, was recorded immediately after fluid collection on the circuit interval timer. The permeation plate 9001 was left in place on the test sample, and the 2-minute timer was started immediately.

[0204] After 2 minutes, the free fluid at the third interface (IFF-3) was measured as follows. The IFF rubber pad was placed on a horizontal, flat, rigid surface. The mass of the fresh monolayer filter paper was measured to an accuracy of 0.0001 g and recorded as IFF-3. 初始 Place the filter paper centered on the IFF rubber pad. Transfer the permeation plate 9001 from the test sample onto the pre-weighed filter paper, centering the plate on the filter paper, and immediately start the 8-minute timer. After 10 seconds on the 8-minute timer, remove the permeation plate 9001 from the filter paper and place it on its side, ensuring the pad side of the plate does not touch the worktable. During the next 10 seconds, measure the mass of the filter paper, accurate to 0.0001 g, and record it as IFF-3. 最终 .

[0205] The surface free fluid (SFF) was measured as follows. After 8 minutes, the mass of a new stack of 5 filter papers was measured to an accuracy of 0.0001 g and recorded as SFF. 初始 Place the stack of filter papers on top of the body side of the test sample, centered above the dosing position. Now gently place the permeation plate 9001 on top of the filter papers, centered on the pad side of the plate, and immediately start a 10-second timer. After 10 seconds, remove the permeation plate 9001 from the filter paper and set it aside. Measure the mass of the stack of 5 filter papers, accurate to 0.0001 g, and record it as SFF. 最终 Proceed to the next step immediately.

[0206] Total rewetting is measured as follows. The mass of a new stack of 5 filter papers is measured, accurate to 0.0001 g, and recorded as REWET. 初始Place the filter paper on top of the body side of the test sample, centered above the weighing position. Now place the filled rewetting weight on top of the filter paper stack, centered on the stack, and immediately start a 30-second timer. After 30 seconds, remove the rewetting weight and measure the mass of the stack of 5 filter papers, accurate to 0.0001g, and record it as REWET. 最终 Before testing the next sample, discard the sample and thoroughly clean it, and then dry the fluid well 9008, fluid reservoir 9003, longitudinal fluid channel 9007 and bottom surface of the permeable plate 9001.

[0207] For each of the measured parameters, the following calculations were performed. The total efflux absorption time was calculated as the sum of ACQ-1, ACQ-2, and ACQ-3, and recorded to an accuracy of 0.1 seconds. This was achieved by analyzing data from IFF-1. 最终 Subtract IFF-1 初始 Calculate IFF-1 and record it, accurate to 0.0001g. Then, calculate IFF-2... 最终 Subtract IFF-2 from the middle 初始 Calculate IFF-2 and record it, accurate to 0.0001g. (This is done by analyzing IFF-3.) 最终 Subtract IFF-3 from the middle 初始 Calculate IFF-3 and record it to an accuracy of 0.0001g. Calculate the total IFF as the sum of IFF-1, IFF-2, and IFF-3 and record it to an accuracy of 0.1g. (This is done by analyzing the SFF...) 最终 Subtract SFF from the middle 初始 Calculate the SFF and record it to an accuracy of 0.0001g. Calculate the total IFF + SFF as the sum of the total IFF and SFF, and record it to an accuracy of 0.1g. (This is done via REWET.) 最终 Subtract REWET 初始 Calculate the total backflow and record it, accurate to 0.0001g.

[0208] The entire procedure was repeated for a total of three replicate test samples. The reported value for each parameter is the arithmetic mean of three separately recorded measurements for each acquisition time accurate to 0.1 seconds (ACQ-1, ACQ-2, and ACQ-3), total efflux absorption time accurate to 0.1 seconds, interfacial free fluid accurate to 0.0001 g (IFF-1, IFF-2, and IFF-3), total IFF accurate to 0.1 g, surface free fluid (SFF) accurate to 0.0001 g, total IFF+SFF accurate to 0.1 g, and total reabsorption accurate to 0.0001 g.

[0209] Fiber density (Dtex)

[0210] Textile fiber webs (e.g., woven fiber webs, nonwoven fiber webs, air-laid fiber webs) are composed of individual material fibers. Fibers are measured as linear mass density, which is reported in decibels. A decibel is the mass (in grams) of fibers present in 10,000 meters of that fiber. The decibel values ​​of fibers within a material's fiber web are often reported by the manufacturer as part of the specifications. If the decibel value of a fiber is unknown, it can be calculated by measuring the cross-sectional area of ​​the fiber using a suitable microscopy technique such as scanning electron microscopy (SEM), determining the fiber composition using suitable techniques such as FT-IR (Fourier Transform Infrared) spectroscopy and / or DSC (Dynamic Scanning Calorimetry), and then calculating the mass (in grams) of fibers present in 10,000 meters of fiber using literature values ​​of the composition's density. All tests were conducted in a chamber maintained at a temperature of 23°C ± 2.0°C and a relative humidity of 50% ± 2%, and samples were conditioned under the same environmental conditions for at least 2 hours prior to testing.

[0211] If necessary, a representative sample of the fiber web material of interest can be removed from the absorbent article. In this case, the fiber web material is removed to prevent the sample from being stretched, deformed, or contaminated.

[0212] SEM images were obtained and analyzed as follows to determine the cross-sectional area of ​​the fibers. To analyze the cross-section of the fiber web material sample, the sample was prepared as follows: A sample approximately 1.5 cm (height) × 2.5 cm (length) without creases or wrinkles was cut from the fiber web. The sample was immersed in liquid nitrogen and the edges were broken along the length of the sample using a razor blade (9# VWR single-edged industrial razor blade, surgical carbon steel). The sample was coated with gold sputtering and then adhered to the SEM mount using double-sided conductive tape (Cu, 3M, purchased from Electron Microscopy Sciences). The sample was oriented such that the cross-section was as perpendicular as possible to the detector to minimize any tilt distortion of the measured cross-section. SEM images were obtained at a resolution sufficient to clearly elucidate the cross-section of the fibers present in the sample. The fiber cross-section can vary in shape, and some fibers may consist of multiple individual filaments. In any case, the area of ​​each cross-section in the fiber cross-section was determined (e.g., using the diameter of circular fibers, the major and minor axes of elliptical fibers, and image analysis for more complex shapes). If the fiber cross-section indicates a non-uniform cross-sectional composition, the area of ​​each identifiable component is recorded, and the partial trait contribution of each component is calculated and subsequently summed. For example, if the fiber is bicomponent, the cross-sectional areas of the core and sheath are measured separately, and the partial trait contributions from the core and sheath are calculated separately and summed. If the fiber is hollow, the cross-sectional area does not include the internal portion of the fiber composed of air, which makes no significant contribution to the fiber partial trait. In summary, at least 100 such measurements of the cross-sectional area are performed for each fiber type present in the sample, and in square micrometers (μm). 2 Record the cross-sectional area a of each fiber in units of ) k The arithmetic mean (accurate to 0.1 μm) 2 ).

[0213] The fiber composition is determined using common characterization techniques such as FTIR spectroscopy. For more complex fiber compositions (such as polypropylene core / polyethylene sheath bicomponent fibers), a combination of common techniques (e.g., FTIR spectroscopy and DSC) may be required to fully characterize the fiber composition. This process is repeated for each fiber type present in the fiber web material.

[0214] The characteristics of each fiber type in fiber web materials k The values ​​are calculated as follows:

[0215]

[0216] Where d k In grams (per 10,000 meters of calculated length), a k With μm 2 As a unit, and In grams per cubic centimeter (g / cm³) 3 The unit is 0.1g. Report the fractions (accurate to 0.1g (per 10,000 meters of length calculated)) and the fiber type (e.g., PP, PET, cellulose, PP / PET bicomponent).

[0217] Basis weight

[0218] The basis weight of the test sample is the mass (in grams) per unit area (in square meters) of a single material layer, and is measured according to Pharmacopoeia Method WSP 130.1. The test sample is cut into blocks of known area, and the mass of the test sample is determined using an analytical balance accurate to 0.0001 g. 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.

[0219] Measurements are performed on test samples taken from rolls or sheets of raw material or from material layers removed from absorbent articles. When removing material layers from absorbent articles, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive. To ensure complete removal of adhesive, the layer is immersed in a suitable solvent that will dissolve the adhesive without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly in a manner that prevents excessive stretching or other deformation of the material. After the material has dried, test specimens are obtained. Test specimens are made as large as possible to account for any inherent material variability.

[0220] Measure the dimensions of the monolayer specimens using a calibrated steel ruler or equivalent from NIST. Calculate and record the area of ​​the specimens, accurate to 0.0001 square meters. Obtain the mass of the specimens using an analytical balance and record it, accurate to 0.0001 grams. Calculate and record the basis weight by dividing the mass (in grams) by the area (in square meters), accurate to 0.01 grams per square meter (gsm). Repeat this process for a total of ten replicate specimens. Calculate and report the arithmetic mean of the basis weights, accurate to 0.01 grams per square meter.

[0221] air permeability

[0222] The air permeability measurements presented in this article were obtained using Worldwide Strategic Partners (WSP) Test Method 70.1.

[0223] thickness

[0224] The thickness of the specimen was measured as the distance between the reference platform on which the specimen was placed and the pressure foot on which a specified amount of pressure was applied to the specimen for a specified period of time. All measurements were performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the test specimens were conditioned in this environment for at least 2 hours prior to testing.

[0225] Thickness was measured using a manually operated micrometer equipped with a pressure foot capable of applying a stable pressure of 0.50 kPa ± 0.01 kPa to the specimen. This manually operated micrometer was a statically heavy instrument with readings accurate to 0.01 mm. A suitable instrument was the Mitutoyo Series 543 ID-C Digimatic, or equivalent, purchased from VWR International. The pressure foot was a flat, circular, movable surface with a diameter smaller than the test specimen, capable of applying the required pressure. A suitable pressure foot had a diameter of 25.4 mm, but smaller or larger pressure feet could be used depending on the size of the specimen being measured. The test specimen was supported by a horizontal, flat reference platform, which was larger than and parallel to the surface of the pressure foot. The system was calibrated and operated according to the manufacturer's instructions.

[0226] If necessary, the sample is obtained by removing it from the absorbent article. When removing the sample from the absorbent article, care is taken not to cause any contamination or deformation to the sample layer during the process. The test sample is taken from an area without creases or wrinkles and is larger than the pressure foot.

[0227] To measure thickness, first zero the micrometer relative to a horizontal, flat reference platform. Place the test specimen on the platform, with the test position centered below the pressure foot. Gently lower the pressure foot at a rate of 3.0 mm ± 1.0 mm per second until full pressure is applied to the test specimen. Wait 5 seconds, then record the specimen thickness to an accuracy of 0.001 mm. Repeat this process for a total of ten test specimens. Calculate the arithmetic mean of all thickness measurements and report the thickness to an accuracy of 0.001 mm.

[0228] Thickness coefficient

[0229] As mentioned earlier, the thickness factor is the thickness per 10 gsm sample basis weight. Therefore, the formula is thickness / (basis weight / 10).

[0230] density

[0231] Density is calculated based on basis weight and thickness, and appropriate unit conversions are performed to obtain density in g / cc.

[0232] Material composition analysis

[0233] The quantitative chemical composition of samples, including mixtures of fiber types, was determined using ISO 1833-1. All measurements were performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0234] Test samples taken from raw material rolls or sheets, or from material layers removed from absorbent articles, are analyzed. When removing material layers from absorbent articles, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive. To ensure complete removal of adhesive, the layer is immersed in a suitable solvent that will dissolve the adhesive without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly to prevent excessive stretching or other deformation of the material. After the material has dried, a sample is obtained and tested according to ISO 1833-1 to quantitatively determine its chemical composition.

[0235] Compressed thickness

[0236] The thickness of the specimen is measured as the distance between a reference platform on which the specimen is placed and a pressure foot on which a specified amount of pressure is applied to the specimen for a specified period of time. For this method, a series of pressures are applied to the test specimen and sustained for a specified time, with a recovery period in between. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the test specimens are conditioned in this environment for at least 2 hours prior to testing.

[0237] Thickness is measured using a manually operated micrometer equipped with a pressure foot capable of applying stable pressure to the test specimen at each specified pressure (+0.01 kPa) in a step pressure series of 0.50 kPa, 1.00 kPa, 2.00 kPa, 3.00 kPa, 5.00 kPa, and 0.50 kPa. This manually operated micrometer is a statically heavy instrument with readings accurate to 0.001 mm. A suitable instrument is the Mitutoyo series 543 ID-C Digimatic, or equivalent, purchased from VWR International. The pressure foot is a flat, circular, movable surface with a diameter smaller than the test specimen, capable of applying the required pressure. A suitable pressure foot has a diameter of 25 cm. 2 The area is [not specified], but smaller or larger pressure feet can be used depending on the size of the specimen being measured. The test specimen is supported by a horizontal, flat reference platform that is larger than and parallel to the surface of the pressure foot. The system is calibrated and operated according to the manufacturer's instructions.

[0238] The test specimen is obtained from a sample of the material being evaluated. The test specimen is taken from an area without creases or wrinkles and is larger than the pressure foot.

[0239] To measure the thickness, first ensure the pressure to be applied to the sample is adjusted to the first pressure in the step pressure series, 0.50 kPa. Now zero the micrometer against a horizontal, flat reference platform. Place the test specimen on the platform, with the test position centered below the pressure foot. Gently lower the pressure foot at a rate of 3.0 mm ± 1.0 mm per second until full pressure is applied to the test specimen. Wait 4 seconds, then record the thickness of the test specimen to an accuracy of 0.001 mm, recording the applied test pressure. Remove the pressure from the test specimen and set a 30-second timer to an accuracy of 0.1 seconds (from any convenient source). Now adjust the pressure to the next pressure setting in the step series, 1.00 kPa, and zero the micrometer against a horizontal, flat reference platform. After 30 seconds, place the test specimen on the platform, with the same test position centered below the pressure foot. In a similar manner, lower the pressure foot and record the thickness of the test specimen to an accuracy of 0.001 mm, recording the applied pressure. Remove the pressure from the test specimen and set a 30-second timer. Repeat the entire process for each pressure in the step pressure series, in the following order: 0.50 kPa, 1.00 kPa, 2.00 kPa, 3.00 kPa, 5.00 kPa, 0.50 kPa. Record the thickness at each pressure, accurate to 0.001 mm, and record the applied pressure. For the 0.50 kPa pressure setting, record the initial 0.50 kPa pressure and the final 0.50 kPa pressure, as well as the thickness. For each applied pressure, apply calipers to the same test position on the test specimen.

[0240] In a similar manner, a total of three parallel test specimens were measured. The arithmetic mean of the thickness measurements at each pressure was calculated and reported as "Thickness," accurate to 0.001 mm. The pressure applied for each measurement was recorded, along with the "Initial Pressure" and "Final Pressure" for the 0.50 kPa setting. From these results, the thickness reduction can be calculated between any pressure settings used by simply subtracting the thickness obtained at the higher pressure from the thickness obtained at the lower pressure, and reported as accurate to 0.001 mm.

[0241] Repeat sampling time and reflow (RATR)

[0242] The collection time of absorbent articles containing artificial menstrual fluid (AMF) as described herein was measured using a strikethrough plate and an electronically timed interval. The time required for the absorbent article to collect a series of doses of AMF was recorded. Backflow testing was performed after the collection tests. All measurements were conducted in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0243] See Figures 4 to 6 B. The permeable plate 9001 is constructed of resin glass with overall dimensions of 10.2 cm long × 10.2 cm wide × 3.2 cm high. A longitudinal groove 9007 extending along the length of the plate is 13 mm deep, 28 mm wide at the top plane of the plate, and its sidewalls slope downwards at a 65° angle to a 15 mm wide sidewall. The central test fluid well recess 9009 is 26 mm long, 24 mm deep, 38 mm wide at the top plane of the plate, and its sidewalls slope downwards at a 65° angle to a 15 mm wide base. At the base of the test fluid well recess 9009, there is an "H"-shaped test fluid reservoir 9003, which leads to the bottom of the plate to introduce fluid onto the test sample below. The test fluid reservoir 9003 has an overall length of 25 mm, a width of 15 mm, and a depth of 8 mm. The longitudinal legs of the reservoir are 4 mm wide and have rounded ends with a radius 9010 of 2 mm. The legs are spaced 3.5 mm apart. The central support bar has a radius of 3 mm (9011) and accommodates opposing electrodes spaced 6 mm apart. The sidewalls of the reservoir curve outward at a radius of 14 mm (9012) defined by an overall width of 15 mm (2013). Lead pellets (or equivalent) are filled into two well recesses (80.5 mm long × 24.5 mm wide × 25 mm deep) located outside the transverse groove to adjust the overall mass of the plate, thereby providing 0.25 psi (17.6 g / cm³) to the test area. 2 The constraint pressure is applied to the electrode 9004, which is embedded in plate 9001. An external banana socket 9006 is connected to the inner wall 9005 of the fluid reservoir 9003. A circuit interval timer is inserted into socket 9006, and the impedance between the two electrodes 9004 is monitored. The time from the introduction of AMF into reservoir 9003 until the AMF is discharged from the reservoir is measured. The timer has a resolution of 0.01 seconds.

[0244] For the reabsorption portion of the test, a pressure of 1.0 psi is applied to the test sample. The reabsorption weight is constructed such that the dimensions of the weight's base match the dimensions of the permeation plate, and the required total mass is calculated to provide a pressure of 1.0 psi on the weight's base. Therefore, the weight's base is 10.2 cm long × 10.2 cm wide and is constructed of a flat, smooth, rigid material (e.g., stainless steel) to provide a mass of 7.31 kg.

[0245] For each test sample, seven layers of filter paper, cut to a diameter of 150 mm, were used as the re-infiltration substrate. Prior to testing, the filter paper was conditioned at 23°C ± 2°C and 50% ± 2% relative humidity for at least 2 hours. Suitable filter paper had a basis weight of approximately 74 gsm, a thickness of approximately 157 micrometers, medium porosity, and was purchased from VWR International as grade 413.

[0246] Remove the test sample from all packaging, being careful not to press or pull the product during handling. Do not attempt to smooth wrinkles. Condition the test sample at 23°C ± 2°C and 50% ± 2% relative humidity for at least 2 hours before testing. Determine the dosing location as follows: For symmetrical samples (i.e., when laterally divided along the midpoint of the sample's longitudinal axis, the front of the sample has the same shape and size as the rear), the dosing 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., when laterally divided along the midpoint of the sample's longitudinal axis, the front of the sample does not have the same shape and size as the rear), the dosing 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 wing.

[0247] The required mass of the permeable plate must be calculated for the specific dimensions of the test sample to allow for the application of a limiting pressure of 0.25 psi. Measure and record the lateral width of the core at the dosing location, accurate to 0.1 cm. The required mass of the permeable plate is calculated as the core width multiplied by the permeable plate length (10.2 cm) multiplied by 17.6 g / cm². 2 Record the required mass to an accuracy of 0.1g. Add lead pellets (or equivalent) to the well depression 9002 in the permeable plate to obtain the calculated mass.

[0248] Connect the electronic circuit timer to the permeation plate 9001 and reset the timer to zero. Place the test sample on a flat, level surface with the body side facing up. Gently place the permeation plate 9001 on the center of the test sample, ensuring that the "H"-shaped reservoir 9003 is centered at the designated dispensing position.

[0249] Using a mechanical pipette, precisely pipette 3.00 mL ± 0.05 mL of AMF into the test fluid reservoir 9003. Dispense the fluid along the molded lip at the bottom of the reservoir 9003 within 3 seconds or less, without splashing. Immediately after fluid collection, record the collection time to the nearest 0.01 second and start a 5-minute timer. Apply the second and third doses of AMF to the test fluid reservoir in a similar manner, with a 5-minute waiting period between each dose. Record the collection time to the nearest 0.001 second. Immediately after the third dose of AMF has been obtained, start the 5-minute timer and prepare the filter paper for the reabsorption portion of the test.

[0250] Obtain the mass of 7 layers of filter paper and record it as dry mass. fp Accurate to 0.001 grams. Five minutes after the third collection, gently remove the permeation plate from the test sample and set it aside. Place seven pre-weighed layers of filter paper on the test sample, centering the stack at the weighing position. Now center the reabsorption weight on top of the filter paper and start a 15-second timer. After 15 seconds, gently remove the reabsorption weight and set it aside. Obtain the mass of the seven layers of filter paper and record it as the wet mass. fp Accurate to 0.001 grams. From wet mass fp Subtract dry mass fp The reabsorption value is reported to be accurate to 0.001 grams. Before testing the next sample, thoroughly clean electrode 9004 and wipe away any residual test fluid from the bottom of the permeation plate and the reabsorption weight.

[0251] Immediately after the rewetting portion of the test, a quantified test sample was used for stain sizing, as described in this article.

[0252] The entire procedure was repeated for ten replicate samples in a similar manner. The reported values ​​are the arithmetic mean of the ten separately recorded acquisition time (first, second, and third) measurements (accurate to 0.001 seconds) and resuspension values ​​(accurate to 0.001 grams).

[0253] Stain size measurement method

[0254] This method describes how to measure the size of visible fluid stains on an absorbent article. The procedure is performed on the test sample immediately after it has been added to the test liquid, according to a separate method as described herein (e.g., repeated sampling and backwashing). The resulting test sample is photographed under controlled conditions. Each photographic image is then analyzed using image analysis software to obtain a measurement of the size of the resulting visible stain. All measurements are performed at constant temperature (23°C ± 2°C) and relative humidity (50% ± 2%).

[0255] The test sample, along with a calibration ruler (traceable to NIST or an equivalent standard), is placed horizontally on a rough black background inside a lightbox that provides stable and uniform illumination across its entire base. A suitable lightbox is the Sanoto MK50 (Sanoto, Guangdong, China) or equivalent, which provides 5500 LUX illumination at a color temperature of 5500K. A digital single-lens reflex (DSLR) camera with manual setting controls (e.g., a Nikon D40X or equivalent from Nikon Inc., Tokyo, Japan) is mounted directly above the opening at the top of the lightbox, ensuring that the entire artifact and ruler are visible within the camera's field of view.

[0256] Using a standard 18% gray card (e.g., Munsell 18% Reflectance (Gray) Neutral Patch / Kodak Gray Card R-27, available from X-Rite; Grand Rapids, MI, or equivalent), set the camera's white balance for the lighting conditions inside the lightbox. Set the camera's manual settings so that the image is correctly exposed and there is no signal cutoff in any color channel. Suitable settings could be an f / 11 aperture, an ISO of 400, and a shutter speed of 1 / 400 second. At a focal length of 35mm, mount the camera approximately 14 inches above the workpiece. Focus the image correctly, take the picture, and save it as a JPEG file. The resulting image must include the entire test sample and distance scale, with a minimum resolution of 15 pixels / mm.

[0257] To analyze the images, they were transferred to a computer running image analysis software (MATLAB, purchased from The Mathworks, Inc., Natick, MA, or an equivalent instrument). The image resolution was calibrated using a calibrated distance scale to determine the number of pixels per millimeter. The images were analyzed by manually drawing the boundaries of the region of interest (ROI) around the visually discernible perimeter of the stain formed by the previously quantitatively tested liquid. The area of ​​the ROI was calculated and reported as the total stain area, accurate to 0.01 mm. 2 Also, specify which method was used to generate the test samples to be analyzed (e.g., repeated collection and refluxing).

[0258] Repeat the entire procedure for all replicate test samples generated by the quantitative dosing method. The reported values ​​are the average of individually recorded measurements for the total stain area, accurate to 0.01 mm. 2 Also, specify which method was used to generate the test samples to be analyzed (e.g., repeated collection and refluxing).

[0259] Preparation of Artificial Menstrual Fluid (AMF)

[0260] Artificial blood serum (AMF) is a mixture of defibrinated sheep blood, phosphate-buffered saline solution, and a mucilage component. AMF is prepared to have a viscosity between 7.15 and 8.65 centistokes at 23°C.

[0261] Measure the viscosity of AMF using a low-viscosity rotational viscometer (a suitable instrument is the Cannon LV-2020 rotational viscometer with a UL adapter from Cannon Instrument Co., State College, PA, or an equivalent instrument). Select an appropriate spindle size within the viscosity range and operate and calibrate the instrument according to the manufacturer's instructions. Measurements should be performed at 23°C ± 1°C and 60 rpm. Report results to an accuracy of 0.01 centistokes.

[0262] The reagents required for AMF preparation include: defibrinated sheep blood with a cell hematocrit of 38% or greater (collected under sterile conditions, purchased from Cleveland Scientific, Inc., Bath, OH, or equivalent); gastric mucin with a target viscosity of 3-4 centistokes when prepared as a 2% aqueous solution (in crude form, purchased from Sterilized American Laboratories, Inc., Omaha, NE, or equivalent); 10% v / v lactic acid aqueous solution; 10% w / v potassium hydroxide aqueous solution; anhydrous disodium hydrogen phosphate (reagent grade); sodium chloride (reagent grade); sodium dihydrogen phosphate monohydrate (reagent grade); and distilled water, each purchased from VWR International or equivalent sources.

[0263] The phosphate buffer solution consists of two separately prepared solutions (solution A and solution B). To prepare 1 L of solution A, add 1.38 ± 0.005 g of sodium dihydrogen phosphate monohydrate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask, and dilute to volume with deionized water. Mix thoroughly. To prepare 1 L of solution B, add 1.42 ± 0.005 g of anhydrous disodium hydrogen phosphate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask, and dilute to volume with deionized water. Mix thoroughly. To prepare the phosphate buffer solution, add 450 ± 10 mL of solution B to a 1000 mL beaker and stir slowly on a stirring plate. Insert a calibrated pH probe (accurate to 0.1) into the beaker containing solution B, and while stirring, add enough solution A to bring the pH to 7.2 ± 0.1.

[0264] The mucus component was a mixture of phosphate-buffered saline solution, potassium hydroxide solution, gastric mucin, and lactic acid solution. The amount of gastric mucin added to the mucus component directly affected the final viscosity of the prepared AMF. To determine the amount of gastric mucin required to obtain AMF within the target viscosity range (7.15 cP to 8.65 cP at 23°C), three batches of AMF with different amounts of gastric mucin were prepared in the mucus component, and the required precise amount was obtained by extrapolation from the concentration-viscosity curve using a three-point least-squares linear fit. The successful range of gastric mucin was typically between 38 g and 50 g.

[0265] To prepare approximately 500 mL of the mucus component, 460 ± 10 mL of the previously prepared phosphate-buffered saline solution and 7.5 ± 0.5 mL of a 10% w / v potassium hydroxide aqueous solution were added to a 1000 mL heavy-duty glass beaker. The beaker was placed on a hot plate with stirring and the temperature was raised to 45 °C ± 5 °C while stirring. A predetermined amount of gastric mucin (± 0.50 g) was weighed and slowly sprayed into the previously prepared liquid, which had reached 45 °C, without agglomeration. The beaker was covered and mixing continued. The temperature of the mixture was raised to above 50 °C but not exceeding 80 °C over 15 minutes. Heating was continued for 2.5 hours while maintaining this temperature range and with gentle stirring. After 2.5 hours, the beaker was removed from the hot plate and cooled to below 40 °C. Then, 1.8 ± 0.2 mL of a 10% v / v lactic acid aqueous solution was added and mixed thoroughly. The mucus component mixture was autoclaved at 121 °C for 15 minutes and cooled for 5 minutes. Remove the mixture of viscous components from the autoclave and stir until the temperature reaches 23℃±1℃.

[0266] The temperature of the sheep blood and mucus components should be maintained at 23°C ± 1°C. Using a 500mL graduated cylinder, measure the volume of the entire batch of the previously prepared mucus component and add it to a 1200mL beaker. Add an equal volume of sheep blood to the beaker and mix thoroughly. Using the viscosity method described above, ensure that the viscosity of the AMF is between 7.15 and 8.65 centistokes. If not, dispose of the batch and prepare another batch as needed to adjust the mucus component.

[0267] Unless intended for immediate use, qualified AMF should be refrigerated at 4°C. After preparation, AMF can be stored in an airtight container at 4°C for up to 48 hours. AMF must be brought to 23°C ± 1°C before testing. Discard any unused portions after testing.

[0268] Dry MD Standard 3-Point Bending

[0269] The flexural properties of the absorbent article test samples were measured on a universal constant-speed extension test frame equipped with a load sensor (suitable instrument being the MTS Alliance using TestSuite software, purchased from MTS Systems Corp., Eden Prairie, MN, or equivalent), with the measured force within 1% to 99% of the load sensor's limits. Testing was performed on dry test specimens. The intent of this method is to simulate the deformation in the xy-plane produced by the wearer of the absorbent article during normal use. All tests were performed in a chamber controlled at 23°C ± 3°C and 50% ± 2% relative humidity.

[0270] The bottom clamp consists of two cylindrical rods, each 3.175 mm in diameter and 110 mm in length, made of polished stainless steel. Each rod has frictionless roller bearings at both ends. These two rods are horizontally mounted, aligned front to back, and parallel to each other. The top radii of the rods are vertically aligned and allow free rotation about the diameter of the cylinder via the frictionless bearings. Furthermore, the clamp allows the two rods to move horizontally away from each other on a track, enabling the creation of a gap between them while maintaining their orientation. The top clamp consists of a third cylindrical rod, also made of polished stainless steel, with a diameter of 3.175 mm and a length of 110 mm, and frictionless roller bearings at both ends. When in the proper position, the rods of the top clamp are parallel to and aligned front to back with the rods of the bottom clamp, and centered between the rods of the bottom clamp. Both clamps include an integrated adapter adapted for mounting in the appropriate position on a universal test frame and locking in place such that the movement of the rods is orthogonal to the movement of the test frame crossbeam.

[0271] Set the gap ("span") between the bars of the lower clamp to 25mm ± 0.5mm (center to center of the bar), with the upper bar centered at the midpoint between the lower bars. Set the gauge length (bottom of the top bar to top of the lower bar) to 1.0cm.

[0272] The thickness (“caliper”) of the test specimen is measured using a manually operated micrometer equipped with a pressure foot capable of applying a stable pressure of 0.1 psi ± 0.01 psi. This manually operated micrometer is a heavy-duty instrument with readings accurate to 0.01 mm. A suitable instrument is the Mitutoyo Series 543ID-C Digimatic, or equivalent, purchased from VWR International. The pressure foot is a flat, circular, movable surface with a diameter not exceeding 25.4 mm. The test specimen is supported by a horizontal, flat reference platform, which is larger than and parallel to the surface of the pressure foot. The micrometer is zeroed against the horizontal, flat reference platform. The test specimen is placed on the platform, centered below the pressure foot. The pressure foot is lowered manually at a rate of 3 ± 1 mm / s until the full weight of the pressure is applied to the specimen. After 5 seconds, the thickness is recorded as the caliper, accurate to 0.01 mm.

[0273] Prior to testing, absorbent samples were conditioned for two hours at 23°C ± 3°C and 50% ± 2% relative humidity. Dry test specimens were taken from a sample area free of any seams, creases, or wrinkles, ideally from the center of the pad (the intersection of the longitudinal and lateral midlines). Dry specimens were prepared for MD (longitudinal) bending by cutting them 50.8 mm wide along CD (transverse; parallel to the lateral axis of the sample) and 50.8 mm long along MD (parallel to the longitudinal axis of the sample), maintaining their orientation after cutting and marking the body-facing surface. The thickness of the test specimen was measured as described herein and recorded as the dry specimen thickness, accurate to 0.01 mm. The mass of the test specimen was obtained and recorded as the dry mass, accurate to 0.001 g. This was calculated by dividing the mass (g) by the area (0.002581 m²). 2 The basis weight of the test specimen is calculated and recorded as the dry sample basis weight, accurate to 0.01 g / m³. 2 By measuring the sample basis weight (g / m³) 2 Divide the quotient by the sample thickness (mm), then divide the quotient by 1000 to calculate the bulk density of the test sample, and record it as the dry sample density, accurate to 0.01 g / cm³. 3 Five repeatable dry test specimens were prepared in a similar manner.

[0274] The general test frame is programmed for the flexural bending test under the following settings. The movement of the chuck begins, causing the top clamp to move downwards relative to the lower clamp at a rate of 1.0 mm / sec until the upper bar contacts the top surface of the specimen with a nominal force of 0.02 N. The chuck then continues to move downwards for an additional 12 mm. The chuck then immediately returns to its original gauge length at a rate of 1.0 mm / s. Force (N) and displacement (mm) data are continuously collected at 100 Hz throughout the test.

[0275] Load the dry test specimen onto the fixture so that it spans the two lower bars and is centered below the upper bar, with its sides parallel to the bars. For MD bending, the MD direction of the test specimen is perpendicular to the length of the three bars. Begin the test and continuously collect force and displacement data during the test.

[0276] Construct a force (N) versus displacement (mm) curve. Determine the maximum peak force from the graph and record it as the dry-state MD peak load, accurate to 0.01 N. Calculate and record the maximum slope of the curve between the initial force and the maximum force (during the loaded portion of the curve), accurate to 0.1 units. Calculate the modulus using the following formula and record it as the dry-state MD modulus, accurate to 0.001 N / mm. 2 .

[0277] Modulus (N / mm) 2 = (slope × (span)) 3)) / (4×sample width×(sample thickness) 3 ))

[0278] Calculate the flexural stiffness using the following formula and record it as the dry-state MD flexural stiffness, accurate to 0.1 N / mm. 2 .

[0279] Bending stiffness (N) mm 2 = Modulus × Moment of Inertia

[0280] Wherein the moment of inertia (mm) 4 = (sample width × (sample thickness)) 3 )) / 12

[0281] The procedure was repeated for all five replicate dry test specimens in a similar manner. For each parameter in the parameters, the arithmetic mean of the five replicate dry test specimens was calculated and reported as the dry specimen thickness (accurate to 0.01 mm) and dry specimen basis weight (accurate to 0.01 g / m³). 2 ), dry sample density (accurate to 0.001 g / cm³) 3 Dry-state MD peak load (accurate to 0.01 N), dry-state MD modulus (accurate to 0.001 N / mm²) 2 ) and dry MD bending stiffness (accurate to N mm) 2 ).

[0282] Wet cohesion compression test

[0283] The wet-state bulging compression test method uses a universal constant-speed extension test frame equipped with a load sensor (suitable instrument being the MTS Alliance, MTS Systems Corp., Eden Prairie, MN, or equivalent, using TestSuite software) to measure the force-displacement behavior of an intentionally “bulged” wetted absorbent article test sample during five cycles of load application (“compression”) and load removal (“recovery”), with the measured force within 1% to 99% of the limits of the load sensor. As described herein, the test is performed on a test specimen to which a specified amount of test liquid has been added. The intent of this method is to simulate the deformation in the z-plane of the crotch area of ​​the absorbent article or its components that occurs when a wearer wears the absorbent article or its components during a sit-to-stand movement. All tests are performed in a chamber controlled at 23°C ± 3°C and 50% ± 2% relative humidity.

[0284] Test equipment in Figures 12 to 14The bottom fixing clamp 3000 consists of two matching sample clamps 3001, each 100 mm wide, mounted on its own movable platforms 3002a, 3002b. Each clamp has a 110 mm long "blade" 3009, which abuts against a 1 mm thick hard rubber surface 3008. When closed, the clamps are flush with the inner sides of their respective platforms. The clamps are aligned so that they hold unconvinced samples horizontally and orthogonally to the tension axis of the tension tester. The platforms are mounted on guide rails 3003, which allow them to move horizontally from left to right and lock into place. The guide rails have adapters 3004 compatible with the tension tester's bracket, enabling the platforms to be fixed horizontally and orthogonally to the tension axis of the tension tester. The upper clamp 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 is compatible with the bracket of the load sensor, which can fix the plunger orthogonal to the tension axis of the tension tester.

[0285] Before testing, condition the test samples at 23°C ± 3°C and 50% ± 2% relative humidity for at least 2 hours. Prepare the test specimens as follows. When testing a complete absorbent article, remove any release paper (if present) from any women's underwear adhesive on the garment-facing side of the article. Lightly apply talcum powder to the adhesive to reduce any stickiness. If hoops are present, cut them off with scissors so as not to interfere with the top sheet or any other underlying layers of the article. Place the article on the worktable with the body-facing surface facing up. Mark the intersection of the longitudinal and transverse center lines on the article. Use a rectangular die or equivalent cutting device to cut a specimen 100 mm longitudinally by 80 mm transversely, centered at the intersection of the center lines. When testing material layers or layered components from an absorbent article, place the material layer or layered component on the worktable and oriented it to be integrated into the finished product, i.e., identify the body-facing surface and the lateral and longitudinal axes. Cut a specimen measuring 100 mm longitudinally and 80 mm transversely using a rectangular die or equivalent cutting device, with its center located at the intersection of the center lines. Measure and record the mass of the specimen, accurate to 0.001 g. The mass (g) is calculated by dividing the area (0.008 m²) by the area. 2 The basis weight of the sample is calculated and recorded as the basis weight, accurate to 1 g / m³. 2The test sample was further prepared by applying a single dose of a 10% w / v saline solution. The saline solution was prepared by adding 100 g of reagent-grade NaCl to a 1 L volumetric flask and adding distilled water to the fill line. The volume of the liquid dose applied to the test sample was 7 mL. The liquid dose was added using a calibrated Eppendorf pipette, spreading the fluid over the entire body-facing surface of the sample over a period of approximately 3 seconds. The wet sample was tested 10.0 min ± 0.1 min after the dose was applied.

[0286] Program the tension tester to zero the load sensor, then lower the upper clamp at 2.00 mm / s until the plunger contact surface contacts the sample and the reading at the load sensor is 0.02 N. Zero the clamp. Program the system to lower the clamp by 15.00 mm at 2.00 mm / s, then immediately raise the clamp by 15.00 mm at 2.00 mm / s. Repeat this cycle for a total of five cycles, without any delay between cycles. Collect data at a frequency of 50 Hz during all compression / decompression cycles.

[0287] Position the left platform 3002a 2.5 mm (distance 3005) from the side of the upper plunger. Lock the left platform in place. Platform 3002a will remain fixed throughout the experiment. Align the right platform 3002b 50.0 mm (distance 3006) from the fixing clamp. Raise the upper probe 2001 so that it does not obstruct the loading of the sample. Open both clamps 3001. (Reference) Figure 13 Place the dry specimen in the clamp with its longitudinal edge (i.e., the 100mm long edge). With the dry specimen laterally centered, secure both edges firmly in the clamp. (Reference) Figure 14 Move the right platform 3002b 30.0 mm toward the fixed platform 3002a. Allow the dry specimen to bend upwards while the moving platform is positioned. Now manually lower the probe 2001 until the bottom surface is approximately 1 cm above the top of the bent specimen.

[0288] Begin testing and continuously collect force (N) versus displacement (mm) data for all five cycles. Plot the force (N) versus displacement (mm) curves individually for each cycle. Representative curves are shown below. Figure 15 From this curve, determine the maximum wet compressive force for each cycle, accurate to 0.01 N, then multiply by 101.97 and record, accurate to 1 gF. (TD-E2) / (TD-E1) Calculate the wet recovery percentage between the first and second cycles, and record it to an accuracy of 0.01%, where TD is the total displacement and E2 is the extension on the second compression curve exceeding 0.02 N. Similarly, calculate (TD-E1) / (TD-E1). Calculate and record the percentage of wet recovery between the first cycle and other cycles, accurate to 0.01%. (Reference) Figure 16 Calculate and record the wet compressibility energy of cycle 1 as the area under the compression curve (i.e., area A+B), accurate to 0.1 N-mm. Calculate and record the wet energy loss of cycle 1 as the area between the compression and decompression curves (i.e., area A), accurate to 0.1 N-mm. Calculate and report the wet recovery energy of cycle 1 as the area under the decompression curve (i.e., area B), accurate to 0.1 N-mm. Calculate and record the wet compressibility energy (N-mm), wet energy loss (N-mm), and wet recovery energy (N-mm) for each of the other cycles in a similar manner, accurate to 0.1 N-mm.

[0289] Now repeat the entire procedure for a total of five repeated wet test specimens, and report the results of each of the five cycles as the arithmetic mean of the following items for the five wet repetitions: wet maximum compressive force (accurate to 1 gf), wet compressive energy (accurate to 0.1 N-mm), wet energy loss (accurate to 0.1 N-mm), and wet recovery energy (accurate to 0.1 N-mm).

[0290] Preparation of novel artificial menstrual fluid (nAMF)

[0291] The formulation of the novel artificial blood serum (nAMF) consists of a mixture of defibrinated sheep blood, phosphate-buffered saline solution, and a mucilage component. nAMF is prepared to have a viscosity between 7.40 and 9.00 centipoise at 23°C.

[0292] Measure the viscosity of nAMF using a low-viscosity rotational viscometer (a suitable instrument is the Brookfield DV2T from AMETEK Brookfield, Middleboro, MA, equipped with a Brookfield UL adapter, or an equivalent instrument). Select a mandrel of appropriate size within the viscosity range and operate and calibrate the instrument according to the manufacturer's instructions. Measurements are performed at 23°C ± 1°C and 60 rpm. Report results to an accuracy of 0.01 centipoise.

[0293] The reagents required for the preparation of nAMF include: defibrinated sheep blood with a cell hematocrit of 38% or greater (collected under sterile conditions, purchased from Cleveland Scientific, Inc., Bath, OH, or equivalent); gastric mucin with a target viscosity of 3 to 4 centipoise when prepared as a 2% aqueous solution (sterile crude form, purchased from American Laboratories, Inc., Omaha, NE, or equivalent); anhydrous disodium hydrogen phosphate (reagent grade); sodium chloride (reagent grade); sodium dihydrogen phosphate monohydrate (reagent grade); sodium benzoate (reagent grade); benzyl alcohol (reagent grade); and distilled water, each purchased from VWR International or equivalent sources.

[0294] The phosphate buffered saline solution consists of two separately prepared solutions (solution A and solution B). To prepare 1 L of solution A, add 1.38 ± 0.005 g of sodium dihydrogen phosphate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask, and add distilled water to the flask. Mix thoroughly. To prepare 1 L of solution B, add 1.42 ± 0.005 g of disodium hydrogen phosphate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask, and add distilled water to the flask. 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 sufficiently large bottle with a well-sealed cap. Then add 1.0 g of sodium benzoate and 1.60 g of benzyl alcohol to the bottle along with a stir bar and set aside.

[0295] The mucus component of nAMF is a mixture of phosphate-buffered saline solution 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 centipoise to 9.0 centipoise at 23°C and 60 rpm), three batches of nAMF with different amounts of gastric mucin were prepared in the mucus component, and the required precise amount was then extrapolated from the concentration-viscosity curve using a least-squares linear fit at three points. The successful range of gastric mucin is typically 13 to 15 grams per 400 mL batch of nAMF, but this can vary significantly based on the supplier, year, and batch of the mucin.

[0296] To prepare approximately 200 mL of the mucus component, a predetermined amount of gastric mucin was added to a flask containing the previously prepared phosphate buffer solution, and then the flask was capped. The flask was placed on a wrist shaker at maximum speed for 5 minutes. After 5 minutes, the flask containing the mucus component was removed from the wrist shaker and placed on a magnetic stirring plate. The mixture was stirred for at least 2 hours until no mucin clumps were present, and then the stir bar was removed from the flask. Using a homogenizer, the mucus component was mixed at 10,000 rpm for 5 minutes. A suitable homogenizer is a T18 Ultra-Turrax equipped with an S18N-19G dispersing tool (19 mm stator diameter, 12.7 mm rotor diameter, and a 0.4 mm gap between the rotor and stator), both of which are available from IKAWorks, Inc., Wilmington, NC, or equivalent. Following the final mixing step, the viscosity of the viscous component was measured and recorded to an accuracy of 0.01 centipoise using a viscometer with a UL adapter at 23°C ± 1°C and 20 rpm. The viscosity of the prepared viscous component was ensured to be within the target range of 9.0 to 11.0 centipoise.

[0297] nAMF is a 50:50 mixture of mucus component and sheep blood. Ensure 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 the mucus component to a glass bottle with a capacity of at least 500 mL. Now add 200 g of sheep blood to the bottle along with a stir bar. Mix on a magnetic stir plate until fully combined. When measured using a viscometer with a UL adapter at 23°C ± 1°C and 60 rpm, ensure the viscosity of the prepared nAMF is within the target range of 7.4 centipoise to 9.0 centipoise. If the viscosity is too high, it can be adjusted by adding the previously prepared phosphate buffer solution in 0.5 g increments, followed by stirring for 2 minutes, and then rechecking the viscosity until the target range is reached.

[0298] Qualified nAMF should be refrigerated at 4°C unless intended for immediate use. After preparation, nAMF can be stored at 4°C in an airtight container for up to 48 hours. Before testing, nAMF must be brought to 23°C ± 1°C. After testing, discard any unused portions.

[0299] Z-compression method

[0300] The Z-compression method uses a load cell on a constant-rate extension (CRE) general mechanical testing system to measure the compressive behavior of the test specimen along the z-direction. The measured force is within 1% to 99% (preferably 100 N) of the sensor's limit value. Suitable instrumentation is MTS Alliance using TestSuite Software, available from MTS Systems Corp., Eden Prairie, MN, or equivalent. All tests are performed in a chamber controlled at 23°C ± 3°C and 50% ± 2% relative humidity.

[0301] The upper and lower clamps of the testing system are circular parallel plate compression plates made of stainless steel. The plate mounted on the movable CRE clamp has a diameter of 40mm, and the plate mounted on the fixed CRE clamp has a diameter greater than 40mm. Both plates have adapters compatible with the CRE testing machine bracket, which can fix the plates so that their opposing surfaces are positioned along a parallel plane orthogonal to the movement of the CRE testing machine beam.

[0302] Prior to testing, the absorbent product samples were conditioned for two hours at 23°C ± 3°C and 50% ± 2% relative humidity. The test samples were removed from their outer packaging, and the protective cover / release paper was removed from the underwear adhesive on the clothing-facing side of the sample. A small amount of talcum powder was applied to the adhesive to reduce any stickiness. To obtain the test specimens for measurement, a circular mold with a diameter of 40 mm was used. If wings were present on the absorbent product test sample, the test specimen was obtained by centering the circular mold at the intersection of the longitudinal midpoint and the lateral line, which is centered within the area containing the wings. If no wings were present, the test specimen was obtained by centering the circular mold at the intersection of the longitudinal midpoint and the lateral midpoint of the absorbent product test sample. Five duplicate test specimens were prepared from five absorbent product test samples in a similar manner.

[0303] A general test frame is prepared for compression testing to measure the force and distance during a loading (compression) and unloading (recovery) cycle, as described below. The chuck movement is programmed to cause the upper clamping plate to move downward relative to the lower clamping plate at a rate of 0.2 mm / s until an end load of 8.66 N (6.9 kPa) is reached, after which the chuck immediately returns to the original gauge length (clamping plate separation distance).

[0304] Perform the test as follows. Move the pressure plates so that the initial distance (gauge length) between the contact surfaces of the pressure plates is 25 mm, and then zero the clamps and load cells. Place the test specimen on the bottom pressure plate with the wearer-facing surface upwards, ensuring the center of the test specimen is centered below the upper pressure plate. Manually adjust the position of the upper pressure plate so that its contact surface is approximately 1 mm above the upper surface of the test specimen. Begin the test and continuously collect force (N) and displacement (mm) data at a rate of 100 Hz.

[0305] Construct a force (N) versus thickness (mm) curve on the data array collected throughout the cycle. Note that at each data point, the thickness is the original gauge length (25 mm) minus the clamp position (mm). Based on the resulting force (N) versus thickness (mm) curve, calculate the area under the loaded (compression) portion of the curve from the initial thickness to the minimum thickness, and record it as the compressive energy, accurate to 0.001 N. mm.

[0306] Repeat the procedure for all five replicate test specimens in a similar manner. Calculate the arithmetic mean of all five replicates and report it as the compressive energy, accurate to 0.001 N. mm.

[0307] Peak load and elongation method

[0308] The peak load and elongation of the test specimens were measured when the specimens were stretched to failure using a universal constant-rate elongation test frame. Measurements were performed on test specimens prepared from the longitudinal (MD) and transverse (CD) sections of the test material. All measurements were conducted in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, with the test specimens conditioned in this environment for at least 2 hours prior to testing.

[0309] A suitable universal constant-speed extension test frame is an MTS Alliance or equivalent that interfaces with a computer running TestSuite control software (purchased from MTS SystemsCorp, Eden Prairie, MN). The universal test frame is equipped with a load sensor, and the force being measured is within 1% to 99% of the sensor's limits. The clamps used to hold the test specimen are lightweight (<80 grams) vise-like clamps with a blade or serrated edge clamping surface at least 35 mm wide. The clamps are mounted on the universal test frame and are installed such that they are horizontally and vertically aligned with each other.

[0310] Measurements are performed on both MD (longitudinal) and CD (transverse) test specimens taken from raw material rolls or sheets, or on test specimens derived from material layers removed from the absorbent article. When removing the material layer from the absorbent article, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive. To ensure complete removal of adhesive, the layer is immersed in a suitable solvent that will dissolve the adhesive without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly in a manner that prevents excessive stretching or other deformation of the material. After the material has dried, the test specimens are obtained as follows. MD test specimens are obtained from any area of ​​the test material free of creases or wrinkles. The MD test specimens are cut to a width of 1 inch (25.4 mm) and a length sufficient to accommodate a test span of 51 mm. The long side of the MD test specimen is parallel to the longitudinal axis of the test material, as it will appear in the absorbent article. Five duplicate MD test specimens are prepared in a similar manner. The CD test specimens were also cut to a width of 1 inch (25.4 mm) and a length sufficient to accommodate a test span of 51 mm. The long side of the CD test specimen was parallel to the lateral axis of the test material, as it would appear in the absorbent article. Five duplicate CD test specimens were prepared in a similar manner.

[0311] The general test frame is prepared for tensile testing to failure at a constant elongation rate, with relaxation compensation and gauge length adjustments as follows. The initial clamp-to-clamp spacing is set to a nominal gauge length (L) of 51 mm. 标称 Then, the clamps are zeroed. The test frame is programmed to move the clamps closer together with an intentional slack of 1 mm to ensure that there is no pre-tension on the test specimen at the start of the test. (During this movement, the specimen will become relaxed between the tension clamps.) Next, the clamps will be moved away at a relaxation rate of 1 mm / s until a relaxation preload of more than 0.10 N is applied. At this point, the following holds true: 1) The clamp position signal (mm) is defined as the specimen relaxation (L... 松弛 2) The initial gauge length (L0) is calculated as the nominal gauge length plus the relaxation L0 = L 标称 +L 松弛 3) The chuck extension (ΔL) is set to zero (0.0 mm). 4) The chuck displacement (mm) is set to zero (0.0 mm). The clamp will then continue to move apart at a test speed of 254 mm / min until the test specimen fails. The clamp will then return to the nominal gauge length.

[0312] The test is performed by inserting the MD test specimen into the clamp so that the specimen's long axis is parallel to and centered with the movement of the clamp. The test is started, and time, force, and displacement data are continuously collected at a data acquisition rate of 100 Hz throughout the test.

[0313] Construct a force (N) versus displacement (mm) curve. Record the maximum force (N) as the MD peak load, accurate to 0.01N. Record the clamp position corresponding to the maximum force as L. 峰值 Accurate to 0.01 mm. Calculate and record the percentage of MD elongation under peak load using the following formula, accurate to 1%.

[0314] Elongation at peak value % = (L 峰值 -L o ) / L o ) 100

[0315] Where L o Previously defined as L 标称 +L 松弛 Now repeat the entire procedure until all five MD test specimens have been tested. For each of the recorded parameters, calculate the arithmetic mean of the five repeated test specimens and record it as the MD peak load, accurate to 0.01 N, and the MD% elongation at the peak, accurate to 1%.

[0316] In a similar manner, the entire procedure was repeated for five CD test specimens, and the arithmetic mean of the five repeated test specimens was calculated and reported as the CD peak load (accurate to 0.01 N) and the CD% elongation at the peak (accurate to 1%).

[0317] Bending length

[0318] For bending length testing, follow the pharmacopoeia method WSP 90.5 (05).

[0319] Examples and Data

[0320]

[0321] Sample 1 of the present invention has a basis weight of 71.68 gsm and contains 25% by weight of viscose cellulose fiber with a density of 1.3 dtex; and 75% by weight of bicomponent fiber, wherein the bicomponent fiber has a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein polyethylene is the skin.

[0322] Sample 2 of the present invention has a basis weight of 65.61 gsm and contains 25% by weight of viscose cellulose fiber with a density of 0.9 dtex; 45% by weight of trilobal polypropylene fiber with a density of 1.0 dtex; and 30% by weight of bicomponent fiber, which has a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein polyethylene is the skin.

[0323] Sample 3 of the present invention has a basis weight of 64.98 gsm and contains 25% by weight of viscose cellulose fiber with a density of 0.9 dtex; 45% by weight of trilobal polypropylene fiber with a density of 1.0 dtex; and 30% by weight of bicomponent fiber, wherein the bicomponent fiber has a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein polyethylene is the skin.

[0324] Sample 4 of the present invention has a basis weight of 57.54 gsm and contains 25% by weight of viscose cellulose fiber with a density of 0.9 dtex; 45% by weight of trilobal polypropylene fiber with a density of 1.0 dtex; and 30% by weight of bicomponent fiber, wherein the bicomponent fiber has a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein polyethylene is the skin.

[0325] Sample 5 of the present invention has a basis weight of 62.00 gsm and contains 25% by weight of viscose cellulose fiber with a density of 0.9 dtex; 45% by weight of trilobal polypropylene fiber with a density of 1.0 dtex; and 30% by weight of bicomponent fiber, wherein the bicomponent fiber has a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein polyethylene is the skin.

[0326]

[0327] Products 1, 2, and 3 of this invention all comprise the same topsheet. The topsheet is a nonwoven topsheet having a basis weight of 24 gsm and is a breathable bonded nonwoven fabric. The breathable bonded nonwoven fabric comprises bicomponent fibers, wherein polyethylene terephthalate and polyethylene are in a core-skin configuration, with polyethylene forming the skin. These fibers comprise 4.4 denier. The topsheet comprises 60% hydrophilic fibers and 40% hydrophobic fibers by weight.

[0328] Products 1, 2, and 3 of this invention all contain the same film. The film is a 12gsm polypropylene film, available from RKW.

[0329] Products 1, 2, and 3 of this invention all contain the same core. The absorbent core is an air-laid absorbent core, which comprises pulp fibers, absorbent binder, and bicomponent fibers, has a basis weight of 150 gsm, and is purchased from Glatfelter (York, Pa., USA), and has an absorbent binder of 22 gsm.

[0330] Product 1 of the present invention further comprises a second layer between the topsheet and the core, the second layer having a basis weight of 71.68 gsm and comprising 25 wt% viscose cellulose fibers with a density of 1.3 dtex; and 75 wt% bicomponent fibers having a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein the polyethylene is the skin. The topsheet is formed by applying an anti-adhesive consisting of about 1 wt% PPG-15 stearyl ether and about 99 wt% caprylic / capric triglycerides, the anti-adhesive having been sprayed onto the wearer-facing surface at an application level of about 2 gsm.

[0331] Product 2 of the present invention further comprises a second layer between the top sheet and the core, the second layer having a basis weight of 65.61 gsm, comprising 25 wt% viscose cellulose fibers with a density of 0.9 dtex; 45 wt% trilobal polypropylene fibers with a density of 1.0 dtex; and 30 wt% bicomponent fibers having a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein the polyethylene is the skin. The top sheet is formed by applying an anti-adhesive consisting of about 1 wt% PPG-15 stearyl ether and about 99 wt% caprylic / capric triglycerides, the anti-adhesive having been sprayed onto the wearer-facing surface at an application level of about 2 gsm.

[0332] Product 3 of the present invention further comprises a second layer between the top sheet and the core, the second layer having a basis weight of 64.98 gsm, comprising 25% by weight of viscose cellulose fibers with a density of 0.9 dtex; 45% by weight of trilobal polypropylene fibers with a density of 1.0 dtex; and 30% by weight of bicomponent fibers having a first component of polyethylene terephthalate and polyethylene in a core-skin configuration, wherein polyethylene is the skin.

[0333] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and the range surrounding its functional equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0334] Examples / paragraphs

[0335] Paragraph 1. A fluid management layer, the fluid management layer comprising:

[0336] a. A nonwoven fabric having a basis weight of about 40 gsm to about 75 gsm.

[0337] b. Approximately 15% to approximately 35% by weight of cellulose fibers,

[0338] c. Approximately 65% ​​to approximately 85% by weight of bonding fibers,

[0339] The fluid management layer has a thickness factor of about 0.26 to about 0.35, and the cellulose fibers and the bonding fibers have a dendritic ratio of less than about 2.

[0340] Paragraph 2. According to the fluid management layer described in paragraph 1, the fluid management layer further includes integrated pins with a pin density between 90 pins / cm² and 220 pins / cm².

[0341] Paragraph 3. The fluid management layer according to paragraphs 1 to 2, wherein the pin orientation is selected from the top pin orientation, the bottom pin orientation, and combinations thereof.

[0342] Paragraph 4. The fluid management layer according to paragraphs 1 to 3, wherein the fiber management layer has an MD:CD peak load ratio of about 0.5 to about 1.75.

[0343] Paragraph 5. The fluid management layer according to paragraphs 1 to 4, wherein the fluid management layer further comprises separating fibers having a dendritic ratio of about 0.5 to about 2.

[0344] Paragraph 6. The fluid management layer according to paragraphs 1 to 5, wherein the separating fibers are selected from polypropylene, polyethylene terephthalate, two-component polyethylene, two-component polypropylene, two-component polyethylene terephthalate, and combinations thereof.

[0345] Paragraph 7. The fluid management layer according to paragraphs 1 to 6, wherein the separating fibers are non-cylindrical polypropylene.

[0346] Paragraph 8. The fluid management layer according to paragraphs 1 to 7, wherein the cellulose fiber is selected from cotton, rayon, viscose, lyocell, natural cellulose, regenerated cellulose, and combinations thereof.

[0347] Paragraph 9. The fluid management system according to paragraphs 1 to 8, wherein the cellulose fiber is viscose fiber.

[0348] Paragraph 10. The fluid management layer according to paragraphs 1 to 9, wherein the bonding fiber is selected from bicomponent polyethylene terephthalate / polyethylene, combinations of polyethylene, polypropylene, and polyethylene terephthalate, copolymers of polyethylene terephthalate, and combinations thereof.

[0349] Paragraph 11. The fluid management layer according to paragraphs 1 to 10, wherein the bonding fiber is polyethylene terephthalate / polyethylene, wherein the core is polyethylene terephthalate and the sheath is polyethylene.

[0350] Paragraph 12. The fluid management layer according to paragraphs 1 to 11, wherein the bonding fibers comprise bicomponent fibers.

[0351] Paragraph 13. The fluid management layer according to paragraphs 1 to 12, wherein the bonding fibers further include non-cylindrical polymer fibers.

[0352] Paragraph 14. The fluid management layer according to paragraphs 1 to 13, wherein the cellulose fibers have a fraction of about 0.5 to about 1.7.

[0353] Paragraph 15. The fluid management layer according to paragraphs 1 to 14, wherein the bonding fibers have a fraction of about 1 to about 2.

[0354] Paragraph 16. The fluid management layer according to paragraphs 1 to 15, wherein the fluid management layer has a peak MD load of about 4 Newtons to about 85 Newtons.

[0355] Paragraph 17. The fluid management layer according to paragraphs 1 to 16, wherein the fluid management layer has a peak CD load of about 4 Newtons to about 130 Newtons.

[0356] Paragraph 18. The fluid management layer according to paragraphs 1 to 17, wherein the average pore size is about 90 µm to about 330 µm.

[0357] Paragraph 19. The fluid management layer according to paragraphs 1 to 18, wherein the average pore size is about 100 µm to about 150 µm.

[0358] Paragraph 20. The fluid management layer according to paragraphs 1 to 19, wherein the length of the fibers is from about 10 mm to about 120 mm.

[0359] Paragraph 21. The fluid management layer according to paragraphs 1 to 20, wherein the length of the fibers is from about 24 mm to about 95 mm.

[0360] Paragraph 22. The fluid management layer according to paragraphs 1 to 21, wherein the length of the fibers is from about 36 mm to about 75 mm.

[0361] Paragraph 23. The fluid management layer according to paragraphs 1 to 22, wherein the fiber length is selected from the same length, different lengths, or combinations thereof.

[0362] Paragraph 24. A disposable absorbent article comprising a top sheet, a bottom sheet, an absorbent core disposed between the top sheet and the bottom sheet, and a fluid management layer disposed between the top sheet and the absorbent core, wherein the fluid management layer comprises a nonwoven fabric having a basis weight of about 40 gsm to about 75 gsm, about 15 wt% to about 35 wt% cellulose fibers, about 65 wt% to about 85 wt% binder fibers, wherein the fluid management layer has a thickness factor of about 0.26 to about 0.35, and wherein the cellulose fibers and the polymer fibers have a denier of less than about 2.

[0363] Paragraph 25. The absorbent article according to paragraph 24, wherein the absorbent article has a Z-compression energy of about 2.6 N·mm to about 4.0 N·mm, a 3-point MD flexural dry stiffness of about 15 N·mm^2 to about 40 N·mm^2, and a wet cohesive compression recovery of more than about 40%.

[0364] Paragraph 26. The absorbent article according to paragraphs 24 to 25, wherein the top sheet contains an anti-adhesive on the wearer-facing side of the top sheet.

[0365] Paragraph 27. The absorbent article according to paragraphs 24 to 26, wherein the anti-adhesive comprises a propylene glycol material.

[0366] Paragraph 28. The absorbent article according to paragraphs 24 to 27, wherein the propylene glycol material is polypropylene glycol.

[0367] Paragraph 29. The absorbent article according to paragraphs 24 to 28, wherein the absorbent article further comprises separating fibers.

[0368] Paragraph 30. The absorbent article according to paragraphs 24 to 29, wherein the separating fibers are selected from polypropylene, polyethylene terephthalate, bicomponent polyethylene, bicomponent polypropylene, bicomponent polyethylene terephthalate, and combinations thereof.

[0369] Paragraph 31. The absorbent article according to paragraphs 24 to 30, wherein the separating fiber is polypropylene.

[0370] Unless expressly excluded or otherwise limited, every reference cited herein, including any cross-references or related patents or patent applications, and any patent application or patent claiming priority to or benefiting from it, is incorporated herein by reference in its entirety. Reference to any reference is not an endorsement of it as prior art to any disclosed or protected art herein, nor is it an endorsement of any such invention, either on its own or in combination with any one or more references. Furthermore, where any meaning or definition of a term in this invention conflicts with any meaning or definition of the same term in referenced documents, the meaning or definition given to that term in this invention shall prevail.

[0371] While specific embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered by the appended claims.

Claims

1. A fluid management layer, the fluid management layer comprising: A nonwoven fabric having a basis weight of about 40 gsm to about 75 gsm, wherein the nonwoven fabric comprises: Cellulose fibers of approximately 15% to approximately 35% by weight. From approximately 65% ​​to approximately 85% by weight of bonding fibers, The fluid management layer has a thickness coefficient of about 0.26 mm to about 0.35 mm, and the cellulose fibers and the bonding fibers have a denier of less than about 2.

2. The fluid management layer according to claim 1, wherein the fluid management layer comprises integrated pins with a pin density between 90 pins / cm² and 220 pins / cm².

3. The fluid management layer of claim 2, wherein the pin orientation is selected from the top, the bottom, and combinations thereof.

4. The fluid management layer of claim 1, wherein the fiber management layer has an MD:CD peak load ratio of about 0.5 to about 1.

75.

5. The fluid management layer according to claim 1, wherein the fluid management layer comprises separating fibers having a dendritic ratio of about 0.5 to about 2.

6. The fluid management layer according to claim 5, wherein the separating fiber is selected from polypropylene, polyethylene terephthalate, two-component polyethylene, two-component polypropylene, two-component polyethylene terephthalate, and combinations thereof.

7. The fluid management layer according to claim 6, wherein the separating fibers are non-cylindrical polypropylene.

8. The fluid management layer according to claim 1, wherein the cellulose fiber is selected from cotton, rayon, viscose fiber, lyocell fiber, natural cellulose, regenerated cellulose, and combinations thereof.

9. The fluid management layer of claim 1, wherein the bonding fiber is selected from bicomponent polyethylene terephthalate / polyethylene, combinations of polyethylene, polypropylene, and polyethylene terephthalate, copolymers of polyethylene terephthalate, and combinations thereof.

10. The fluid management layer according to claim 1, wherein the cellulose fibers have a fraction of about 0.5 to about 1.

7.

11. The fluid management layer of claim 1, wherein the bonding fibers have a fraction of about 1 to about 2.

12. The fluid management layer of claim 1, wherein the fluid management layer has a peak MD load of about 4 Newtons to about 85 Newtons, and wherein the fluid management layer has a peak CD load of about 4 Newtons to about 130 Newtons.

13. The fluid management layer of claim 1, wherein the average pore size is about 90 µm to about 330 µm.

14. The fluid management layer of claim 1, wherein the length of the fiber is from about 10 mm to about 120 mm.

15. An absorbent article comprising a top sheet, a bottom sheet, and an absorbent core disposed between the top sheet and the bottom sheet, and a fluid management layer according to claim 1 disposed between the top sheet and the absorbent core.

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