Absorbent articles with improved performance

Abstract

Disposable absorbent articles are disclosed that have a topsheet, a backsheet, an absorbent core disposed between the topsheet and the backsheet, and a fluid management layer disposed between the topsheet and the absorbent core. The disposable absorbent articles provide improved fluid acquisition, improved stain size control, and improved performance when wet.

Description

Technical Field

[0001] The present disclosure generally relates to disposable absorbent articles having improved performance characteristics.

Background Art

[0002] Disposable absorbent articles are widely used by various consumers. Generally, disposable absorbent articles include a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet. Users of such disposable absorbent articles have several desired qualities in the absorbent article selected by the user. For example, in the context of feminine hygiene products, users typically desire an article that is soft and has a cushioned feel. Users also typically desire good fluid capture so that the topsheet does not feel wet. Also, users typically desire elasticity. That is, the article should be able to at least somewhat recover its shape by the force applied to the article by the user, for example when the user is moving.

[0003] Regarding an article that is soft and has a cushioned feel, unfortunately, this desire often conflicts with elasticity. The amount of force required to compress the article can affect the level of softness provided by the article. The stronger the force, the more typically a "harder" product is perceived. Similarly, an absorbent article that is elastic can include materials that resist such compressive forces. Thus, an elastic article may not be perceived as "soft". However, an absorbent article having good elasticity can help to adapt to the forces applied during use. An absorbent article having good elasticity can help the absorbent article to recover its shape despite these forces. In contrast, an absorbent article with low elastic quality tends to bunch or compress during use without recovering when exposed to these forces. Unfortunately, bunching or compression of the absorbent article can cause some discomfort and also lead to leakage.

[0004] Furthermore, some consumers may desire a product that provides a desired amount of protection while also having sufficient thickness and rigidity to be flexible. Very high materials can be used to provide thick, cushioned-feeling articles. However, during use, these very high materials may experience various compression loads. Recovery from these compression loads is crucial for maintaining the cushioned feel of the article. What exacerbates this problem is the fact that when fluid is introduced into the article, the properties of the absorbent article's materials change. Thus, an article that may meet the consumer's required criteria before use may no longer be comfortable, flexible, or have the desired rigidity for the user after a given amount of fluid has been absorbed by the absorbent article. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] Therefore, there is a need to create an absorbent article having improved fluid capture, softness, and elasticity. MEANS FOR SOLVING THE PROBLEMS

[0006] The absorbent article of the present disclosure includes a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet. A fluid management layer may be disposed between the topsheet and the absorbent core. The fluid management layer includes a carded fiber nonwoven material including a plurality of integrated fibers.

[0007] The disposable absorbent article has a topsheet, a backsheet, an absorbent core disposed between the topsheet and the backsheet, and an integrated nonwoven fluid management layer disposed between the topsheet and the absorbent core. The absorbent article exhibits an average capture rate for the first jet of from about 5 seconds to about 13 seconds, more preferably from about 5 seconds to about 12 seconds, or most preferably from about 5 seconds to about 11 seconds when measured according to the repeated capture and rewetting method disclosed herein. The fluid management layer has a basis weight in the range of 40 gsm to 75 gsm when measured by the basis weight method, 10 wt% to about 60 wt% absorbent fibers, about 15% to about 70% elastic fibers, and about 25 percent to about 70 percent stiffening fibers when measured by material composition analysis.

Brief Description of the Drawings

[0008] This specification concludes with claims that particularly point out and distinctly claim the subject matter regarded as the invention, but it is believed that the invention will be better understood from the following description when read in conjunction with the accompanying drawings. Some of the figures may be simplified by omitting selected elements for the purpose of more clearly showing other elements. The omission of such elements in some of the figures does not necessarily indicate the presence or absence of a particular element in any of the exemplary embodiments, except as expressly recited in the corresponding written description. None of the drawings are necessarily to scale.

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DETAILED DESCRIPTION OF THE INVENTION

[0009] As used herein, the following terms shall have the meanings specified hereinafter.

[0010] "Absorbent article" refers to a wearable device that absorbs and / or contains liquid substances, and more specifically, to a device that is placed on or near the wearer's body to absorb and contain various excretions discharged from the body. Examples of absorbent articles include diapers, training pants, adult incontinence underwear (e.g., liners, pads, and briefs), and / or feminine hygiene products.

[0011] As used herein, the term "integrated" is used to describe fibers of a nonwoven material that are twisted, entangled, and / or pushed in / pulled out in the positive and / or negative Z-direction (the direction of the thickness of the nonwoven material). Some exemplary processes for integrating the fibers of a nonwoven web include the spunlace process and the needle punch process. The spunlace process uses multiple high-pressure water jets to entangle the fibers. The needle punch process involves using needles to push in and / or pull out the fibers to entangle them with other fibers in the nonwoven.

[0012] As used herein, the term "carded" is used to describe the structural characteristics of the fluid management layer described herein. Carded nonwovens use fibers cut to a specific length, also known as "staple length fibers". The staple length fibers can be of any suitable length. For example, the staple length fibers may have a length of up to 120 mm, or may have a short length of about 10 mm. However, when a particular group of fibers are staple length fibers, e.g., viscose fibers, the lengths of the viscose fibers in the carded nonwoven are generally the same, i.e., the staple length. It is particularly noteworthy that when additional fiber types of longer staple lengths, e.g., polypropylene fibers, are included, the lengths of the polypropylene fibers in the carded nonwoven are also generally the same. However, the staple length of viscose and the staple length of polypropylene may be different.

[0013] In contrast, continuous filaments produced by methods such as the spunbond method or the meltblown method do not produce staple length fibers. Instead, these filaments are of indefinite length and are not cut to a specific length as described for fibers of staple fiber length.

[0014] The "longitudinal" direction is the direction that extends parallel to the maximum linear dimension of the article, typically the longitudinal axis of the article, and includes directions within 45° of the longitudinal direction. As used herein, the "length" of an article or its component generally refers to the magnitude / distance of the maximum linear dimension of the article or its part, or typically the magnitude / distance of its longitudinal axis.

[0015] The "lateral" or "transverse" direction is perpendicular to the longitudinal direction, i.e., the direction that lies in the same plane as most of the article and the longitudinal axis, and the transverse direction is parallel to the transverse axis. As used herein, the "width" of an article or its component refers to the magnitude / distance of the dimension that is perpendicular to the longitudinal direction of the article or its component, i.e., perpendicular to the length of the article or its component, and typically refers to the distance / magnitude of the dimension parallel to the transverse axis of the article or component.

[0016] The "Z direction" is perpendicular to both the longitudinal and transverse directions.

[0017] As used herein, "Machine Direction" or "MD" means the direction parallel to the flow of carded staple fiber nonwoven fabric through a nonwoven fabric making machine and / or an absorbent article manufacturing apparatus.

[0018] As used herein, "Cross Machine Direction" or "CD" means the direction parallel to the width of a carded staple fiber nonwoven fabric making machine and / or an absorbent article manufacturing apparatus and perpendicular to the machine direction.

[0019] The disposable absorbent article of the present disclosure includes a wearer-facing surface and a clothing-facing surface on the opposite side. The topsheet may form at least a part of the wearer-facing surface, and the backsheet may form at least a part of the clothing-facing surface. The absorbent core is disposed between the topsheet and the backsheet, and the fluid management layer is disposed between the absorbent core and the topsheet.

[0020] The topsheet and the backsheet may be joined together to form the outer periphery of the disposable absorbent article. The peripheral portions of the absorbent core and / or the fluid management layer may be disposed inside the outer periphery. For example, the absorbent core may have an edge portion extending generally parallel to the transverse axis and a side edge portion extending generally parallel to the longitudinal axis. Each of the edge portion and the side edge portion may be disposed inside the outer periphery. Similarly, the fluid management layer may include an edge portion extending generally parallel to the transverse axis and a side edge portion extending generally parallel to the longitudinal axis. The edge portion and the side edge portion may be disposed inside the outer periphery. Or, the edge portion may be adjacent to the outer periphery to the extent that the edge portion intersects the outer periphery. In addition to or independently of the edge portion of the fluid management layer, the side edge portion of the fluid management layer may be adjacent to the outer periphery of the absorbent article.

[0021] In addition, the edge portions and / or side edge portions of the absorbent core and / or the fluid management layer may be essentially curved. For example, the side edge portion of the absorbent core and / or the fluid management layer may curve inward from the end toward the transverse axis. Such a configuration can assist in the conformability of the absorbent article. Similarly, in combination with or independently of the side edge portion of the absorbent core and / or the fluid management layer, the edge portion may have a curved path that is generally concave or generally convex.

[0022] The fluid management layer of the present disclosure includes a plurality of carded and integrated fibers. The fluid management layer provides an increased caliper to absorbent articles that can be converted into articles with a softer feel. Additionally, the fluid management layer of the present disclosure can provide an increased elasticity to absorbent articles relative to the elasticity of currently available absorbent articles. Typically, there is a trade-off between elasticity and softness. Softer materials can be difficult to recover their shape from forces applied in one or more directions. Conversely, this can also apply to elastic materials. In the context of absorbent articles, elastic materials typically exhibit good recovery from applied forces. However, they are not typically perceived as being very soft. It is also noteworthy that many absorbent articles can exhibit good elastic properties when dry. However, when they absorb liquid contaminants, their elasticity substantially decreases. The absorbent articles of the present disclosure exhibit good elastic properties in both dry and wet states.

[0023] In addition to the advantages of softness and elasticity of the absorbent articles of the present disclosure, some additional advantages include bleed size control and faster fluid capture. Bleed size is important in the manner in which absorbent articles are perceived. In the context of menstruation, if the bleed is large, the user may feel that the product is hardly functioning just from the appearance of the bleed with respect to the outer perimeter of the absorbent article. In contrast, a smaller bleed, since it is more inside the outer perimeter than a large bleed, can provide the user with the assurance that the absorbent article will not stop functioning.

[0024] Regarding fluid capture speed, this attribute is important for making the user feel dry and clean. If the absorbent article takes a long time to drain liquid contaminants from the topsheet, the user may feel wet. Additionally, if the fluid remains on the topsheet for an extended period, the user may feel that the skin in the delicate zone is dirty.

[0025] As described above, the fluid management layer is an integrated, carded nonwoven material. The fluid management layer of the present disclosure may subsequently include one or more carded webs that are fibers integrated with each other. If only one carded web is utilized, the fibers of the carded web are integrated.

[0026] A variety of configurations for the fluid management layer can be achieved. However, it is important that the fluid management layer of the present disclosure has sufficient openness to allow for rapid capture of fluids. In view of this, the carded webs that make up the fluid management layer may differ from each other. For example, one of the carded webs may include a different fiber blend than the others. Specifically, assuming that the first carded web is located closest to the wearer-facing surface of the absorbent article, the selection of the fibers of the first carded web can be such that this web has a greater openness. The second carded web can be configured similarly. In contrast, the third carded web may be configured to collect liquid contaminants from the void spaces of the first and second carded webs and effectively distribute these liquid contaminants to the absorbent core. When the fiber composition of one of the carded webs is different from the fiber composition of another carded web, when two carded webs are integrated, it is a heterogeneous configuration. Alternatively, when the carded webs are integrated, those having the same fiber composition throughout are called homogeneous configurations.

[0027] When the card processing web(s) are integrated, they cannot be manually separated without at least a significant amount of labor and time. Each card processing nonwoven web forms a layer throughout the fluid management layer. Each layer can maintain its unique properties over at least a portion of the layer along the z-direction even when integrated into a larger fluid management layer. The fluid management layer can provide capillary suction that "draws in" fluid through the topsheet, which competes for trickle / low flow conditions. The fluid management layer can also provide a distribution function to not only contain the exudate by efficiently utilizing the absorbent core but also provide an intermediate storage until the absorbent core can receive the fluid.

[0028] As described above, absorbent articles that exhibit a soft cushion-like feel, good elasticity, and fluid handling characteristics are in accordance with the present disclosure. The caliper of the internal fluid management layer is important. In particular, the typical caliper of webs from conventional spunlace lines achieves a caliper coefficient of 0.03 - 0.12 (caliper per gram per square meter basis weight). In contrast, the fluid management layer of the present disclosure can exhibit a caliper coefficient of at least 0.13 mm, more preferably at least about 0.15 mm, or most preferably about 0.2 mm (including any value within these ranges and any range defined by these ranges). The fluid management layer of the present disclosure can have a caliper coefficient of 0.13 mm to about 0.3 mm, or more preferably about 0.14 mm to about 0.25 mm, or most preferably about 0.15 mm to about 0.22 mm (including all values within these ranges and any range defined by these ranges). Caliper data is provided below for samples of the present invention and comparative samples. The caliper and caliper coefficient of the fluid management layer of the present disclosure can be measured by the caliper and caliper coefficient test methods disclosed herein. It is important to note that the above-described caliper coefficient relates to the caliper obtained using an applied pressure of 0.5 kPa as described in the caliper method disclosed herein.

[0029] The inventors have surprisingly discovered that a simpler process route can be utilized to manufacture a span lace web to achieve an increase in the caliper coefficient. Generally, the web route through the water flow intersection line is serpentine, subjecting the web to both compressive and tensile stresses. This serpentine web route requires a water jet pressure high enough to entangle the fibers and creates a tensile strength sufficient to withstand subsequent web processing. These water jets are applied to both sides of the web. This additional water pressure required to create sufficient entanglement for tensile strength generally exceeds the pressure required to create the desired fluid treatment pore structure, significantly reducing the caliper of the resulting web. In addition, the web is subjected to significant radial compressive and tensile stresses when the web is wound around various vacuum drums and rolls, whereby additional water jets can further entangle the constituent fibers of the layer. Furthermore, these webs can then be wound around a dryer drum to subject them to additional compressive forces. However, the inventors have found that winding the web around these rolls causes compression of the web and actually reduces the caliper of the web.

[0030] In contrast, the inventors have discovered that the caliper of the fluid management layer of the present disclosure can be maintained by using a simplified web route that reduces radial compressive stress / excessive tensile force and by appropriate selection of the fibers within the fluid management layer. For example, the use of rolls and the number of water jets utilized can be reduced by the simplified route. Thus, the level of entanglement is not up to the extent provided by conventional processes, but sufficient tensile strength within the web can be provided by selecting an appropriate combination of fibers as disclosed herein, e.g., stiffening fibers that can be heat treated. Again, the simplified route and appropriate fiber selection described herein enable the fluid management layer of the present disclosure to achieve a caliper coefficient that has not been achievable heretofore.

[0031] In addition, the caliper coefficient of the fluid management layer of the present disclosure was derived from caliper data from the material wound into a roll for storage / transport. Pre-winding of the caliper measurement can be performed, which would result in a much higher caliper coefficient. However, such caliper measurements may not necessarily reflect the fluid management layer as an article.

[0032] The fluid management layer of the present disclosure can have a basis weight of up to 75 grams per square meter (gsm), or up to 70 gsm, or preferably in the range of about 30 gsm to about 75 gsm, more preferably about 45 gsm to about 70 gsm, and most preferably about 50 gsm to about 65 gsm (including any value within these ranges and any range defined by these ranges).

[0033] Some absorbent articles may not require as large a basis weight as described above. For example, liners that generally do not have the same level of absorbency as menstrual pads can have a reduced basis weight relative to the basis weights described above. For example, the fluid management layer can have a basis weight of 20 gsm to 70 gsm, or more preferably 35 gsm to about 65 gsm, or most preferably about 40 gsm to about 60 gsm (specifically, including all values within these ranges and any range defined by these ranges). In one particular embodiment, the fluid management layer of the present disclosure can have a basis weight of about 45 gsm to about 55 gsm. The basis weight of the fluid management layer of the present disclosure can be measured by the basis weight method disclosed herein.

[0034] The inventors have also found that the process technology for creating a caliper in a fluid management layer can be utilized not only for spunlace materials with heterogeneous layers, but also for spunlace materials with homogeneous layers, for example, where each layer has the same fiber composition. Additionally, the inventors have surprisingly found that the spunlace material constructed in this process with appropriate fiber selection also provides improved fluid handling performance over spunlace materials manufactured by typical spunlace processes, along with good elasticity and recovery from compression.

[0035] It is also worth noting that since the fibers are integrated, the fluid management layer does not require an adhesive or latex binder for stabilization. Additionally, the carded nonwoven fabric of the fluid management layer of the present disclosure can be manufactured from a suitable combination of fiber types that impart the desired performance characteristics. For example, the fluid management layer can include a combination of stiffening fibers, absorbent fibers, and elastic fibers.

[0036] As will be described in more detail below, the types of fibers within the fluid management layer of the present disclosure are described in relation to their functions within the fluid management layer. For example, absorbent fibers are utilized to absorb liquid contaminants. Stiffening fibers are utilized to be bonded together by heat treatment, thereby providing rigidity and elasticity to the fluid management layer. Elastic fibers are utilized to provide recovery from compressive forces acting on the fluid management layer.

[0037] To enhance the integration stabilization effect, crimped carded fibers can be utilized. One or more of the absorbent fibers, stiffening fibers, and elastic fibers may be crimped prior to integration. For example, when synthetic fibers are used, these fibers can be mechanically crimped by meshing teeth. With respect to absorbent fibers, these fibers can be mechanically crimped and / or have chemically induced crimping due to variable film thicknesses formed during the formation of the absorbent fibers.

[0038] As described above, the amount of absorbent fibers can affect the absorption of liquid contaminants into the wearer-facing surface or the topsheet. However, when absorbent fibers absorb liquid, they tend to lose some of their structural integrity. The loss of structural integrity can reduce the elasticity of the absorbent article, resulting in an increase in bunching and an increase in leakage. Thus, in principle, while most of the absorbent fibers are good at rapidly discharging liquid contaminants from the wearer-facing surface and / or the topsheet, most can also cause other problems in absorbent articles as described above.

[0039] In view of the potential problems associated with having too high a weight percentage of absorbent fibers, the inventors have found that the fluid management layer of the present disclosure can preferably comprise from about 10 wt% to about 60 wt%, more preferably from about 15 wt% to about 50 wt%, and most preferably from about 20 wt% to about 40 wt% (specifically including any value within these ranges and any range defined by these ranges) of absorbent fibers. In one particular embodiment, the fluid management layer can comprise from about 20 wt% to about 30 wt% of absorbent fibers. The weight percentages of absorbent fibers, elastic fibers, and / or stiffening fibers can be measured by the material composition analysis methods disclosed herein.

[0040] In addition, due to the loss of integrity of the absorbent fibers when wet, the fluid management layer may also include a sufficient weight percentage of elastic fibers to affect the recovery of the absorbent article from the compression loads experienced during use. The inventors have found that the fluid management layer of the present disclosure can comprise from about 15 wt% to about 70 wt%, more preferably from about 20 wt% to about 60 wt%, or most preferably from about 25 wt% to about 50 wt% (specifically listing all values within these ranges and any range defined by these ranges) of elastic fibers. In one particular embodiment, the fluid management layer can comprise from about 30 wt% to about 40 wt% of elastic fibers.

[0041] Furthermore, in order to help the fluid management layer of the present disclosure provide elasticity to the absorbent article, rigidifying fibers can be utilized. For example, as described later, during manufacturing, the rigidifying fibers can be bonded to each other by heat-treating the fluid management layer. This bonding of the rigidifying fibers creates a support matrix that contributes to the elasticity and rigidity of the fluid management layer. In view of this, the fluid management layer can include from about 25% to about 70% by weight, more preferably from about 30% to about 60%, or most preferably from about 40% to about 55% (specifically, listing all values within these ranges and any ranges defined by these ranges) of rigidifying fibers. In one particular embodiment, the fluid management layer can include from about 40% to about 50% by weight of rigidifying fibers.

[0042] As described above, the fluid management layers of the present disclosure can impart a soft cushion-like feel with good elasticity to their corresponding absorbent articles. When caliper, elasticity, and a soft cushion-like feel are desired, the weight percentage of the rigidifying fibers can be made greater than or equal to the weight percentage of the elastic fibers. The weight percentage of the absorbent fibers can be made less than the weight percentage of the elastic fibers and / or the rigidifying fibers. Generally, a higher weight percentage of absorbent fibers is thought to be beneficial for quickly absorbing fluid contaminants. However, considering that the absorbent fibers are close to the topsheet, it is beneficial for the absorbent core to dehydrate the absorbent fibers. When the proportion of absorbent fibers is greater, generally a larger core is required to dehydrate the absorbent fibers. This generally leads to higher costs. In view of this, the weight percentage ratio of absorbent fibers to rigidifying fibers in the fluid management layer of the present disclosure can be from about 1:7 to about 2:1, more preferably from about 1:4 to about 1.5:1, most preferably from about 1:2 to about 1:1 (specifically, listing all values within these ranges and any ranges defined by these ranges). Similarly, the weight percentage ratio of absorbent fibers to elastic fibers can be from about 1:7 to about 3:1, more preferably from about 1:2 to about 2:1, or most preferably from about 1:1.5 to about 1:1 (specifically, listing all values within these ranges and any ranges defined by these ranges).

[0043] Regardless of whether the fluid management layer is used in adult incontinence articles, menstrual articles, liners, or other hygiene articles, it is important that the fluid management layer has the ability to capture liquid contaminants from the topsheet and draw the liquid far enough away from the topsheet so that the topsheet does not feel wet. To achieve this, the inventors have found that the increased caliper of the fluid management layer discussed herein can promote fluid capture due to an increase in the void volume of the fluid management layer. A larger caliper at a lower basis weight is equivalent to a larger void volume with higher permeability. Additionally, the increased caliper of the fluid management layer can also provide the advantage of bleed masking. That is, the bleed visible through the topsheet of an absorbent article using the fluid management layer of the present disclosure appears much smaller than the bleed of their conventional fluid management layers.

[0044] Regarding the basis weight of the fibers, it is particularly noteworthy that fibers with a larger diameter can provide a larger void volume between adjacent fibers compared to fibers with a smaller diameter. Therefore, the fiber size of the fibers within the fluid management layer can be important. For example, regarding the set weight percentage of the fibers, as the fiber size increases, there are fewer fibers per gram, and fewer fibers can be equivalent to a larger space between the fibers. Ideally, particularly in the context of menstrual fluid, the fluid management layer can have a void volume and a certain degree of capillary action for discharging from the topsheet.

[0045] With the above in mind, the inventors have also surprisingly discovered that by carefully selecting the fiber type and the linear density of the fiber type in each layer within the fluid management layer, the desired results of rapid capture and low rewetting can be achieved. The fiber type of each individual layer will be described in more detail below. It is particularly noteworthy that the following considerations regarding the fiber type within the layers of the fluid management layer assume that the first carded nonwoven web is located closer to the topsheet than the web(s) of additional card(s).

[0046] Some suitable linear density values of the absorbent fibers for use in the fluid management layer of the present disclosure are provided. For example, the linear density of the absorbent fibers may range from about 1 dtex to about 7 dtex, more preferably from about 1.4 dtex to about 6 dtex, or most preferably from about 1.7 dtex to about 5 dtex (specifically, enumerating all values within these ranges and any ranges defined by these ranges). In one particular embodiment, the absorbent fibers can have a linear density of about 1.7 dtex. The dtex of the absorbent fibers, stiffening fibers, and elastic fibers can be measured by the fiber decitex method disclosed herein.

[0047] The absorbent fibers of the fluid management layer can have any suitable shape. Some examples include trilobal, "H", "Y", "X", "T", circular, or flat ribbon. Further, the absorbent fibers can be solid, hollow, or multi-hollow. Other examples of suitable multi-lobed absorbent fibers for use in the fluid management layer detailed herein are disclosed in U.S. Patent No. 6,333,108 to Wilkes et al., U.S. Patent No. 5,634,914 to Wilkes et al., and U.S. Patent No. 5,458,835 to Wilkes et al. The trilobal shape can improve wicking and masking properties. Suitable trilobal rayon is available from Kelheim Fibres and is sold under the trade name Galaxy. Each layer may include absorbent fibers of different shapes as described above, but not all carding devices are suitable for handling such variations between / among the layers. In one particular example, the fluid management layer includes round absorbent fibers.

[0048] Any suitable absorbent material for the absorbent fibers can be utilized. Some examples of absorbent materials include cotton, pulp, rayon, or regenerated cellulose, or combinations thereof. In one example, the fluid management layer 30 can include viscose cellulose fibers. The length of the absorbent fibers can range from about 20 mm to about 100 mm, or more preferably from about 30 mm to about 50 mm, or most preferably from about 35 mm to about 45 mm (specifically, enumerating all values within these ranges and any ranges defined by these ranges). Generally, the fiber length of pulp is about 4 - 6 mm, and because the pulp fibers are too short, they cannot be used in conventional carding machines. Thus, if pulp is desired as the fiber in the fluid management layer, additional processing may be required to add the pulp to the carded web. As an example, the pulp may be air-laid between the carded webs, and this combination is subsequently integrated. As another example, tissue may be used in combination with the carded web, and this combination may subsequently be integrated.

[0049] As described above, in addition to the absorbent fibers, the fluid management layer of the present disclosure may include stiffening fibers. The stiffening fibers can be used to help provide structural integrity to the fluid management layer. The stiffening fibers can be useful in enhancing the structural integrity of the fluid management layer in the machine direction and / or the cross-machine direction, thereby facilitating the handling of the web when processing the fluid management layer for incorporation into a disposable absorbent article.

[0050] Some suitable linear density values for the stiffening fibers are provided. For example, the linear density of the stiffening fibers can range from about 1.0 dtex to about 6 dtex, more preferably from about 1.5 dtex to about 5 dtex, or most preferably from about 2.0 dtex to about 4 dtex (specifically, enumerating all values within these ranges and any ranges defined by these ranges). In another specific embodiment, the dtex of the stiffening fibers is about 2.2 dtex.

[0051] Some examples of suitable stiffening fibers include bicomponent fibers comprising polyethylene and polyethylene terephthalate components or polyethylene terephthalate and copolyethylene terephthalate components. The components of the bicomponent fibers can be arranged in a core-sheath configuration, a parallel configuration, an eccentric core-sheath configuration, a trilobal configuration, etc. In one particular embodiment, the stiffening fibers can include bicomponent fibers having a polyethylene / polyethylene terephthalate component arranged in a concentric core-sheath configuration where the polyethylene is the sheath.

[0052] Other materials may be useful, but the inventors have found that the rigidity of polyethylene terephthalate is useful for forming an elastic structure. In contrast, the polyethylene component of the stiffening fibers can be utilized to bond to each other during heat treatment. This can help provide tensile strength to the web in both the MD and CD. Additionally, by bonding the polyethylene component to other polyethylene components of the stiffening fibers, fixing points can be formed in the nonwoven fabric. These fixing points can reduce the amount of sliding between the fibers, thereby enhancing the elasticity of the material.

[0053] One advantage of the stiffening fibers is that the integrated nonwoven fabric can be heat treated after fiber entanglement. The heat treatment can provide further structural integrity to the integrated nonwoven fabric by forming bonds between adjacent stiffening fibers. Therefore, when the proportion of stiffening fibers is high, more bonding points can be formed. If there are too many bonding points, a much stiffer fluid management layer is provided, which can have a negative impact on comfort / softness. Thus, the weight percentage of the stiffening fibers is extremely important when designing absorbent articles.

[0054] Regarding the heat - curing process, any suitable temperature can be utilized. Also, the suitable temperature can be partially influenced by the chemical nature of the components of the stiffening fibers and also by the fluid management layer being processed. For example, the web of the fluid management layer can be heat - cured at a temperature of about 132°C. However, it is also worthy of note that in order to impart uniform rigidity characteristics across the fluid management layer, some heating operation needs to be set up to provide uniform heating to the web of the fluid management layer. Even a slight variation in temperature can have a significant impact on the tensile strength of the fluid management layer.

[0055] As described above, the fluid management layer of the present disclosure includes elastic fibers. The elastic fibers can help the fluid management layer maintain its permeability and compression recovery. Fibers of any suitable diameter can be used. For example, the elastic fibers can have a linear density of about 4 dtex to about 15 dtex, more preferably about 5 dtex to about 12 dtex, or most preferably about 6 dtex to about 10 dtex (specifically, listing all values within these ranges and any ranges defined by these ranges). In a particular embodiment, the fluid management layer may include elastic fibers having a variable cross - section, such as circular and hollow helical, and / or elastic fibers having a variable dtex. In yet another particular embodiment, the elastic fibers of the present disclosure may have a dtex of about 10. In such a form, the elastic fibers may be hollow helical.

[0056] The elastic fiber can be any suitable thermoplastic fiber such as polypropylene (PP), polyethylene terephthalate, or other suitable thermoplastic fibers well-known in the art. The length of the elastic fiber may range from about 20 mm to about 100 mm, or more preferably from about 30 mm to about 50 mm, or most preferably from about 35 mm to about 45 mm. The thermoplastic fiber can have any suitable structure or shape. For example, the thermoplastic fiber can be circular, or can have other shapes such as spiral, corrugated elliptical, trilobal, corrugated ribbon-like, and others. Further, the PP fiber can be solid, hollow, or multi-hollow. The elastic fiber can be solid and round in shape. Other suitable examples of the elastic fiber include polyester / co-extruded polyester fibers. Further, other suitable examples of the elastic fiber include two-component fibers such as polyethylene / polypropylene, polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, etc. These two-component fibers can be configured as a sheath and a core. The two-component fibers can provide a cost-effective means for increasing the basis weight of the material and, in addition, enabling optimization of the pore size distribution.

[0057] The elastic fibers may be polyethylene terephthalate (PET) fibers or other suitable non-cellulosic fibers known in the art. The PET fibers may have any suitable structure or shape. For example, the PET fibers may be circular or may have other shapes such as helical, corrugated elliptical, trilobal, corrugated ribbon-like, hollow helix, and others. Further, the PET fibers may be solid, hollow, or multi-hollow. In a particular embodiment, the fibers may be fibers made of hollow / helical PET. Optionally, the elastic fibers may be helically crimped or flat crimped. The elastic fibers may have a crimp value of about 4 to about 12 crimps per inch (cpi), or about 4 to about 8 cpi, or about 5 to about 7 cpi, or about 9 to about 10 cpi. Specific non-limiting examples of the elastic fibers are available from Wellman, Inc. (Ireland) under the trade names H1311 and T5974. Other examples of elastic fibers suitable for use in the carded staple fiber nonwovens detailed herein are disclosed in U.S. Patent No. 7,767,598 to Schneider et al.

[0058] It is particularly worth noting that the rigid fibers and the elastic fibers need to be carefully selected. For example, although the chemical properties of the components of the rigid fibers and the elastic fibers may be similar, the elastic fibers must be selected such that the melting point of its constituent material is higher than that of the rigid fibers. Otherwise, during heat treatment, the elastic fibers may bond to the rigid fibers (or vice versa), and an overly rigid structure may be formed.

[0059] Although not bound by theory, for absorbent fiber weight percentages greater than about 30 percent, within the gsm ranges disclosed herein, elastic fibers and / or stiffening fibers are believed to be preferably carefully selected. For a soft, cushioned fluid management layer having a caliper coefficient of at least 0.13 or greater as described herein, the elastic fibers and / or stiffening fibers can be selected to offset loss of structural integrity of the absorbent fibers when wet. For example, a higher dtex of elastic fibers can be beneficial to offset the loss of integrity experienced by the absorbent fibers. In such an example, elastic fibers having a dtex of from about 5 dtex to about 15 dtex, more preferably from about 6 dtex to about 12 dtex, or most preferably from about 7 dtex to about 10 dtex can be utilized.

[0060] In addition to, or instead of, these, stiffening fibers may be configured to provide greater structural integrity. For example, the stiffening fibers may include bicomponent fibers of a core-sheath configuration where the sheath is copolyethylene terephthalate. However, such a change in material can create further problems. For example, joining the material to the fluid management layer can only be by adhesive, as opposed to melt bonding.

[0061] In addition to or independent of the foregoing, yet another example is an increase in the bonding of the stiffening fibers. When the absorbent fibers constitute more than 30 weight percent of the fluid management layer, the heat at which the stiffening fibers are bonded can be increased and / or the exposure time can be increased. Thereby, the number of bonds in the stiffening fiber matrix can be increased, thereby offsetting the loss of integrity of the absorbent fibers when wet. However, an increase in the number of bonds results in an increase in stiffness. The increase in stiffness may reduce the user's perception of softness. Similarly, in addition to, or instead of, this, when the absorbent fibers constitute 30 weight percent or more, the linear density of the stiffening fibers may be increased to suppress the loss of integrity of the absorbent fibers. In such an example, the linear density of the stiffening fibers may be from about 3 dtex to about 6 dtex, more preferably from about 4 dtex to about 6 dtex.

[0062] Although it may appear that the solution to wet disintegration is simply to use fibers of larger dtex, it is worthy of note that their use must be balanced. Particularly in the case of viscous fluids, the fluid management layer of the present disclosure can have a certain degree of capillary action to assist in the discharge of liquid contaminants to the wearer-facing surface of the article. Unfortunately, the use of fibers of larger dtex can provide the advantage of caliper but also impair capillary action, thereby causing fluid handling problems.

[0063] The fluid management layer of the present disclosure may be incorporated into various absorbent articles. An exemplary schematic view showing an absorbent article of the present disclosure, namely a sanitary napkin, is shown in FIG. 1A. As shown in the figure, the absorbent article 10 according to the present disclosure includes a topsheet 20, a backsheet 50, and an absorbent core 40 disposed between the topsheet 20 and the backsheet 50. A fluid management layer 30 is disposed between the topsheet 20 and the absorbent core 40. The absorbent article has a wearer-facing surface 60 and a clothing-facing surface 62 opposite to the wearer-facing surface 60. The wearer-facing surface 60 mainly consists of the topsheet 20, and the clothing-facing surface 62 mainly consists of the backsheet 50. Further components may be included in either the wearer-facing surface 60 and / or the clothing-facing surface 62. For example, when the absorbent article is an incontinence pad, a pair of barrier cuffs extending generally parallel to the longitudinal axis L of the absorbent article 10 may form a part of the wearer-facing surface 60. Similarly, an adhesive may be present on the backsheet 50 and form a part of the clothing-facing surface 62 of the absorbent article.

[0064] An exemplary configuration of the fluid management layer of the present disclosure is shown in FIG. 1B. As shown in the figure, the fluid management layer 30 includes edge portions 32A and 32B on opposite sides that can extend generally parallel to the transverse axis T. The fluid management layer 30 also includes side edge portions 31A and 32B that can extend generally parallel to the longitudinal axis L. Similarly, the absorbent core 40 includes edge portions 42A and 42B on opposite sides that can extend generally parallel to the transverse axis T. The absorbent core 40 can also include side edge portions 41A and 41B that extend generally parallel to the longitudinal axis L.

[0065] As shown in the figure, each of the edge portions 32A and 32B of the fluid management layer 30 can be disposed outside the longitudinal direction of the absorbent core 40. However, this is not necessarily required. For example, the edge portions 32A and / or 32B may have the same spread as the absorbent core 40, or the edge portions 32A and / or 32B may be disposed inside the longitudinal direction of the edge portions 42A and / or 42B of the absorbent core 40.

[0066] Similarly, the side edge portions 31A and / or 31B can be disposed outside the lateral direction of the side edge portions 41A and / or 41B of the absorbent core 40. Alternatively, the side edge portions 31A and / or 31B may have the same spread as the side edge portions 41A and / or 41B of the absorbent core 40.

[0067] An exemplary process for forming the fluid management layer of the present disclosure is shown in FIG. 2. As shown in the figure, the plurality of carding machines 210, 220, and 230 can each form a carded nonwoven web (e.g., 214, 224, and 234, respectively), and the carded nonwoven webs are transferred to the carrier belt 240. Each of the carded nonwoven webs 214, 224, and 234 can be supplied to the carrier belt 240 via web shoots 212, 222, 232, respectively. It is also worth noting that after the carded nonwoven 214 is deposited on the carrier belt 240, the carded nonwoven 224 is deposited on the first carded nonwoven 214 on the carrier belt 240. Similarly, the third carded nonwoven web 234 is deposited on the second carded nonwoven 224 and the first carded nonwoven 214 on the carrier belt 240. Subsequently, each of the first, second, and third carded nonwoven webs 214, 224, and 234 is supplied to an integration process 250 that interlaces the fibers of the first, second, and third carded nonwoven webs using either needles and / or high-pressure water jets. Both the carding process and the integration process are well known in the art.

[0068] Additional carding machines may be utilized. In addition, the fluid management layer of the present disclosure may be manufactured using only two of the three cards. In such an example, the first carded web 214 is deposited on the carrier belt 240. Subsequently, the second carded web 224 is deposited on the first carded web 214. Then, the first carded web 214 and the second carded web 224 are integrated as described herein.

[0069] It is particularly worth noting that the various configurations of the fluid management layer can be realized by the configuration shown in the schematic diagram of FIG. 2. However, it is important that the fluid management layer of the present disclosure has a sufficient degree of openness to enable rapid capture of fluids, but can also contain liquid contaminants to reduce the possibility of rewetting. Considering this, the card processing webs, namely 214, 224, and / or 234, can be different from each other. For example, one of the card processing webs may contain a different fiber blend. Specifically, assuming that the first card processing web is located closest to the wearer-facing surface of the absorbent article, the selection of the fibers of the first card processing web 214 can be such that this web has a greater degree of openness. The second card processing web 224 can be configured similarly. In contrast, the third card processing web 234 may be configured to collect liquid contaminants from the void spaces of the first and second card processing webs 214 and 224 and effectively distribute these liquid contaminants to the absorbent core. Alternatively, the first card processing web 214, the second card processing web 224, and the third card processing web 234 may be configured similarly.

[0070] A schematic diagram of an exemplary fluid management layer according to the present disclosure is shown in FIG. 3. As shown, the fluid management layer 30 includes a first surface 300A and an opposite second surface 300B. The fluid distribution layer 30 includes two or more layers along the Z direction between the first surface 300A and the second surface 300B.

[0071] Disposable absorbent articles comprising a fluid management layer were constructed and tested. In addition, disposable absorbent articles of comparative examples were constructed and tested. The difference between the samples of the present invention and the comparative examples was simply the fluid management layer. The samples of the present invention included the fluid management layer of the present disclosure as described above, while the absorbent articles of the comparative examples included fluid management layers currently available on the market.

[0072] For each of the samples of the present invention and the comparative examples, the following components were utilized.

[0073] Top Sheet - The top sheet of each of the sample and the comparative sample of the present invention was a hydroformed film having micro-openings and macro-openings. The film is currently available from Tredegar Corp. (USA).

[0074] Absorbent Core - The absorbent core was an airlaid absorbent core containing pulp fibers, an absorbent gelling material, and bicomponent fibers, having a basis weight of 182 gsm available from Glatfelter (York, PA, USA).

[0075] For each of the sample of the present invention and the comparative example, the following were the constituent materials of their fluid management layers.

[0076] Fluid Management Layer of Comparative Example - A basis weight of 50 gsm having 40 wt% viscose cellulose fibers having 1.7 dtex, 20 wt% polyethylene terephthalate having 4.4 dtex, and 40 wt% bicomponent fibers having a first component of polypropylene having 1.7 dtex and a second component of polyethylene.

[0077] Fluid Management Layer of Sample of the Present Invention - A basis weight of 55 gsm having 20 wt% viscose cellulose fibers having 1.7 dtex, 30 wt% hollow spiral polyethylene terephthalate fibers having 10 dtex, and 50 wt% bicomponent fibers having a core-sheath structure with polyethylene terephthalate and polyethylene as the first component with polyethylene as the sheath.

[0078] Table 1 shows the caliper of the fluid management layer of the sample of the present invention relative to the comparative sample. Note that the caliper was taken at 0.5 kPa. Each of the fluid management layers was removed from the final product.

[0079]

Table 1

[0080] As shown in the illustration, the fluid management layer of the present disclosure is 80% thicker than its comparative sample with only a 10% basis weight difference. Also, as described above regarding the caliper coefficient, for the sample of the present invention, as shown in Table 2, it is much higher than the caliper coefficient of the comparative sample.

[0081]

Table 2

[0082] Table 3 shows the capture rate of the fluid management layer of the sample of the present invention with respect to the comparative sample.

[0083]

Table 3

[0084] As shown in the illustration, the fluid management layer of the sample of the present invention captures liquid contaminants 30% faster than the fluid management layer of the comparative sample. The fluid management layer of the present disclosure can exhibit a capture rate of less than about 10 seconds, less than about 8 seconds, or most preferably less than about 7 seconds when measured according to the liquid wicking time test method described herein. For example, the fluid management layer of the present disclosure can exhibit a capture time in the range of about 5 seconds to about 10 seconds, more preferably about 5 seconds to about 9 seconds, or most preferably about 5 seconds to about 8 seconds (specifically, enumerating all values within these ranges and any ranges defined by these ranges) when measured according to the liquid wicking time test method described herein.

[0085] Regarding the soft cushion-like properties of the fluid management layer of the present disclosure, reference is now made to FIG. 4. The fluid management layer of the present disclosure is graphically shown by the lines associated with group 410, while the comparative samples of the fluid management layer are graphically shown by the lines associated with group 420. As shown, the fluid management layer of the present disclosure (samples of the present invention) exhibits a higher caliper during and after compression compared to the comparative samples. Even after repeated cycles of compression and relaxation, the fluid management layer of the samples of the present invention continues to provide a higher caliper. This can be rephrased as the fluid management layer of the samples of the present invention being softer and more cushion-like than the comparative samples. The data of the graph shown in FIG. 4, as well as the data in Tables 4A - 4C, were obtained by the dynamic mechanical analysis method disclosed herein. The data provided in Tables 4A - 4C pertain to the fluid management layers of the samples of the present invention and the comparative samples and were constructed as described above.

[0086]

Table 4

[0087] The data in Table 4A show that the average caliper of the samples of the present invention is greater than the average caliper of the comparative samples at all steps, whether at 0.2 kPa or 8 kPa. In fact, the data also show that the average caliper of the samples of the present invention under 8 kPa compression is greater than the caliper of the fluid management layer of the comparative samples under a pressure of only 0.2 kPa, except for step 1.

[0088] It is worth noting that the caliper of the caliper shown in Table 1 versus the caliper of Table 4A was obtained at different pressures, namely 0.5 kPa versus 0.2 kPa. Thus, the calipers shown are much larger than the calipers listed in Table 1. However, from the perspective of initial wear, i.e., in Step 1, it is also worth noting that the user would have a much softer absorbent article considering a caliper that is twice as large as the fluid management layer of the present disclosure, and as shown by the compression in Step 2, it is considered that the user can feel the softness. The remaining steps, i.e., Steps 3 - 10, are considered to be able to better reflect the behavior of the fluid management layer during use, i.e., the elasticity of the fluid management layer of the present disclosure.

[0089] Thus, in the fluid management layer according to the present disclosure, the caliper (measured according to the dynamic mechanical analysis method disclosed herein) in Step 1 may be greater than about 0.9 mm, greater than about 1.2 mm, or most preferably greater than about 1.5 mm. For example, the caliper of the fluid management layer according to the present disclosure can have a caliper (measured according to the dynamic mechanical analysis method disclosed herein) of about 1.0 mm to about 2.4 mm, more preferably about 1.1 mm to about 2.2 mm, or most preferably about 1.3 mm to about 2.0 mm (specifically, listing all values within these ranges and any ranges defined by these ranges). To achieve a caliper of 2.4 mm, the basis weight may be about 60 gsm to about 75 gsm.

[0090] For wearing experience, for example, in steps 2 to 10, the caliper of the fluid management layer configured according to the present disclosure is greater than about 0.45 mm at 8 kPa and greater than about 0.65 mm at 0.2 kPa, or more preferably greater than about 0.5 mm at 8 kPa and greater than about 0.7 mm at 0.2 kPa, or most preferably greater than about 0.60 at 8 kPa and greater than about 0.8 mm at 0.2 kPa (when measured by the dynamic mechanical analysis method disclosed herein). For example, the fluid management layer according to the preset disclosure has a caliper of about 0.45 mm to about 0.9 mm at 8 kPa, more preferably about 0.50 mm to about 0.8 mm at 8 kPa, or most preferably about 0.55 mm to about 0.75 mm at 8 kPa (specifically, enumerating all values within these ranges and any ranges defined by these ranges) (when measured by the dynamic mechanical analysis method disclosed herein). In addition, or independently thereof, the fluid management layer of the present disclosure has a caliper of about 0.65 mm to about 1.50 mm at 0.2 kPa, more preferably about 0.75 mm to about 1.40 mm at 0.2 kPa, or most preferably about 0.8 mm to about 1.20 mm at 0.2 kPa (specifically, enumerating all values within these ranges and any ranges defined by these ranges) (when measured by the dynamic mechanical analysis method disclosed herein).

[0091] In Table 4B, the compression distance, which is the amount of decrease in caliper between the initial states, for example, steps 1, 3, 5, 7, and 9, and the compressed states, that is, steps 2, 4, 6, 8, and 10.

[0092]

Table 5

[0093] As shown in Table 4B, the fluid management layer of the sample of the present invention also exhibits a compression distance greater than that of the comparative sample. For example, the fluid management layer configured in accordance with the present disclosure may have a compression distance of greater than about 0.60 mm (when measured by the dynamic mechanical analysis method disclosed herein) from Step 1 to Step 2. Here too, as described above, the initial caliper and compression can be considered to represent the initial feel obtained by the user when using the article. On the other hand, the subsequent Step 2 is considered to be a measure for more usage experience. From Step 1 to Step 2, the fluid management layer of the present disclosure, when measured by the dynamic mechanical analysis method disclosed herein, can exhibit a compression distance of about 0.60 mm to about 1.4 mm, more preferably about 0.7 mm to about 1.4 mm, or most preferably about 0.8 mm to about 1.4 mm (specifically, listing all values within these ranges and any ranges defined by these ranges).

[0094] During the in-use steps, for example, from Step 3 to Step 10, the fluid management layer of the present disclosure, when measured by the dynamic mechanical analysis method disclosed herein, can exhibit a compression distance of about 0.30 mm to about 1.0 mm, more preferably about 0.40 mm to about 0.8 mm, or most preferably about 0.45 mm to about 0.7 mm (specifically, listing all values within these ranges and any ranges defined by these ranges).

[0095] Table 4C provides additional data regarding the difference in compression distance and the percent difference between the fluid management layer of the sample of the present invention and the fluid management layer of the comparative sample.

[0096]

Table 6

[0097] Referring now to FIGS. 5A-6D, scanning electron microscope images of the fluid management layer of the comparative sample (FIGS. 5A-5D) and the fluid management layer of the sample of the present invention (FIGS. 6A-6D) are shown. As shown, looking at the scale indicators on both images, the sample of the present invention has a larger caliper than the caliper of the comparative sample. Additionally, it is noted that there are more fibers associated with the sample of the present invention that extend from and are partially disposed on the first surface. Further, based on the images, more of the fibers partially disposed on the first surface are looped. That is, these fibers have a first fiber end that extends from the first surface and a second end that extends to the first surface. In contrast, most of the fibers of the comparative sample disposed on the first surface have their corresponding first ends that extend from the first surface, but also have a second end disposed on the first surface.

[0098] With respect to the article of the sample of the present invention relative to the comparative sample, several attributes of the article were measured as shown below. First, the article of the sample of the present invention had a capture rate that was much faster than the capture rate of the article of the comparative sample. See Table 5.

[0099]

Table 7

[0100] As shown, the article of the sample of the present invention was averaged at a rate 22 percent faster than the article of the comparative sample during the first ejection, 36 percent faster than the article of the comparative sample during the second ejection, and 36 percent faster than the article of the comparative sample during the third ejection. Also, although capture rate and rewetting are typically considered to be opposing interests, the sample of the present invention provides comparable rewetting measurements compared to the article of the comparative sample. It is particularly noted that the rewetting measured for the sample of the present invention and the article of the comparative sample was not statistically significant. The capture time and rewetting values of the absorbent article according to the present disclosure can be measured by the repeated capture and rewetting methods disclosed herein.

[0101] Therefore, in view of the above, the articles of the present disclosure can exhibit a capture speed of less than 13 seconds, more preferably less than 12 seconds, or most preferably less than 11 seconds for the first ejection. For example, the articles of the present disclosure can exhibit a capture speed for the first ejection in the range of about 5 seconds to about 13 seconds, more preferably about 5 seconds to about 12 seconds, or most preferably about 5 seconds to about 11 seconds (specifically, including all values within these ranges and any ranges defined by these ranges).

[0102] Regarding the second ejection, the articles of the present disclosure can exhibit a capture speed of less than 23 seconds, more preferably less than 21 seconds, or most preferably less than about 18 seconds. For example, the articles of the present disclosure can exhibit a capture time for the second ejection in the range of about 9 seconds to about 23 seconds, more preferably about 9 seconds to about 21 seconds, or most preferably about 9 seconds to about 18 seconds (specifically, including all values within these ranges and any ranges defined by these ranges).

[0103] Regarding the third ejection, the articles of the present disclosure can exhibit a capture speed of less than about 31 seconds, more preferably less than 29 seconds, or most preferably less than 27 seconds. For example, the articles of the present disclosure can exhibit a capture speed for the third ejection in the range of about 15 seconds to about 31 seconds, more preferably about 15 seconds to about 29 seconds, or most preferably about 15 seconds to about 27 seconds (specifically, enumerating all values within these ranges and any ranges defined by these ranges).

[0104] It is particularly worthy of note that there is a far greater significance in the fact that the samples of the present invention also have smaller differences from the capture time of the first ejection to the second ejection, from the second ejection to the third ejection, and from the first ejection to the third ejection. As described above, the fluid management layer of the present disclosure can withstand the loss of integrity of the absorbent fibers better than the fluid management layer of its comparative sample. Table 6 lists the differences between the first and second ejections, the second and third ejections, and the first and third ejections for the samples of the present invention and the comparative samples.

[0105]

Table 8

[0106] As shown, the samples of the present invention lost capture speed at a much lower rate than the comparative samples did from ejection to ejection. For example, the absorbent article of the present disclosure can exhibit a difference between a second ejection and a first ejection of less than about 11 seconds, more preferably less than about 9 seconds, or most preferably less than about 8 seconds. As another example, the absorbent article of the present disclosure can exhibit a difference between a second ejection and a first ejection of from about 3 seconds to about 10 seconds, more preferably from about 3 seconds to about 8 seconds, or most preferably from about 3 seconds to about 7 seconds (specifically, listing all values within these ranges and any ranges defined thereby).

[0107] Regarding the difference between the third ejection and the second ejection, the samples of the present invention also showed a smaller difference than their comparative samples here. For example, the absorbent article configured according to the present disclosure can exhibit a difference between the third ejection and the second ejection of less than about 9 seconds, more preferably less than about 8 seconds, or most preferably less than about 7 seconds. As another example, the absorbent article of the present disclosure can exhibit a difference between the third ejection and the second ejection of from about 3 seconds to about 8 seconds, more preferably from about 3 seconds to about 7.5 seconds, or most preferably from about 3 seconds to about 7 seconds (specifically, listing all values within these ranges and any ranges defined thereby).

[0108] Regarding the difference between the third ejection and the first ejection, the samples of the present invention also showed a smaller difference than their comparative samples here. For example, the absorbent article configured according to the present disclosure can exhibit a difference between the third ejection and the first ejection of less than about 20 seconds, more preferably less than about 17 seconds, or most preferably less than about 14 seconds. As another example, the absorbent article of the present disclosure can exhibit a difference between the third ejection and the first ejection of from about 9 seconds to about 20 seconds, more preferably from about 9 seconds to about 17 seconds, or most preferably from about 9 seconds to about 15 seconds (specifically, listing all values within these ranges and any ranges defined thereby).

[0109] Also, as shown, the articles of the present disclosure can exhibit the capture rates described above and can exhibit rewetting of less than about 1.0 gram, more preferably less than about 0.9 gram, or most preferably less than about 0.8 gram. For example, the articles of the present disclosure can exhibit rewetting values in the range of about 0.1 gram to about 1.0 gram, more preferably about 0.1 gram to about 0.9 gram, or most preferably about 0.1 gram to about 0.8 gram (specifically including all values within these ranges and any ranges defined by these ranges).

[0110] In addition, as described above, the articles of the present disclosure can function well to reduce the wicking size. Data regarding the average wicking size exhibited by the articles is provided in Table 7.

[0111] [Table 9]

[0112] As shown, the articles of the invention of the present disclosure exhibited wicks that were on average 35 percent smaller than the wicks of the comparative samples when measured according to the wicking size test method. Thus, the articles of the present disclosure can exhibit a wicking size of less than about 2400 mm 2 less than, about 2100 mm 2 less than, or most preferably less than about 1800 mm 2 For example, the articles of the present disclosure can exhibit a wicking size of about 1200 mm 2 to about 2400 mm 2 more preferably about 1200 mm 2 to about 2100 mm 2 or most preferably about 1200 mm 2 to about 1950 mm 2 (specifically listing all values within these ranges and any ranges defined by these ranges).

[0113] The fluid management layer of the present disclosure can provide users with absorbent articles that are soft and have a more cushioned feel. However, the fluid management layer of the present disclosure also provides users with appropriate rigidity so that the resulting absorbent articles can reduce the possibility of bunching. A metric that can measure the rigidity of the fluid management layer is the MD bend length. The fluid management layer of the present disclosure can have an MD bend length of from about 4 mN / cm to about 12 mN / cm (specifically, enumerating all values within these ranges and any ranges defined by these ranges).

[0114] Absorbent article Referring again to FIGS. 1A and 1B, as described above, the disposable absorbent article of the present disclosure can include a topsheet 20 and a backsheet 50. Between them, a fluid management layer 30 and an absorbent core 40 can be sandwiched. Additional layers may be disposed between the topsheet 20 and the backsheet 50.

[0115] The topsheet 20 can be joined to the backsheet 50 by an attachment method (not shown) such as those well known in the art. The topsheet 20 and the backsheet 50 may be directly joined to each other at the outer peripheral portion of the article, or they may be indirectly joined to each other by directly joining them to the absorbent core 40, the fluid management layer 30, and / or additional layers disposed between the topsheet 20 and the backsheet 50. This indirect or direct joining can be achieved by attachment methods well known in the art.

[0116] The topsheet 20 can be compliant, have a soft feel, and be non-irritating to the skin of the wearer. Suitable topsheet materials include water-permeable materials that are oriented towards the wearer's body, contact the body, and allow body excretions to rapidly penetrate through it without the fluid flowing back through the topsheet to the wearer's skin. The topsheet can allow for rapid movement of fluid through the topsheet while also allowing a lotion composition to move or migrate onto the outer or inner portion of the wearer's skin.

[0117] A suitable topsheet 20 can be made from a variety of materials such as woven and nonwoven materials; perforated film materials including perforated thermoplastic films, perforated plastic films, and entangled fiber perforated films; hydroformed thermoplastic films; porous foams; reticulated foams; reticulated thermoplastic films; thermoplastic scrims; or combinations thereof.

[0118] Suitable perforated film materials for use as the topsheet include perforated plastic films that are non-absorbent and permeable to body exudates and that minimize or eliminate backflow of fluid through the topsheet. Non-limiting examples of other suitable formed films, including perforated and non-perforated films, are more fully described in U.S. Patent No. 3,929,135, issued to Thompson on December 30, 1975; U.S. Patent No. 4,324,246, issued to Mullane et al. on April 13, 1982; U.S. Patent No. 4,342,314, issued to Radel et al. on August 3, 1982; U.S. Patent No. 4,463,045, issued to Ahr et al. on July 31, 1984; U.S. Patent No. 5,006,394, issued to Baird on April 9, 1991; U.S. Patent No. 4,609,518, issued to Curro et al. on September 2, 1986; and U.S. Patent No. 4,629,643, issued to Curro et al. on December 16, 1986.

[0119] Non-limiting examples of woven and non-woven materials suitable for use as a topsheet include fibrous materials made from natural fibers (e.g., cotton including 100% organic cotton), modified natural fibers, synthetic fibers, or combinations thereof. These fibrous materials may be hydrophilic or hydrophobic, but the topsheet is preferably hydrophobic or becomes hydrophobic. Optionally, a portion of the topsheet can be made hydrophilic using any known method of making a topsheet containing a hydrophilic component. The non-woven fiber topsheet 20 may be manufactured by any known procedure for making a non-woven web, non-limiting examples of which include spunbonding, carding, wet laying, air laying, meltblowing, needle punching, mechanical entanglement, thermo-mechanical entanglement, and hydroentanglement.

[0120] The topsheet 20 can also be formed from a combination of a perforated film and a non-woven fabric. For example, a film web and a non-woven web can be combined as described in U.S. Patent No. 9,700,463. Alternatively, the film may be extruded onto the non-woven material, which is thought to enhance the contact between the film layer and the non-woven material. Exemplary processes for such combinations are described in U.S. Patent Nos. 9,849,602 and 9,700,463.

[0121] The backsheet 50 can be disposed adjacent to the garment-facing surface of the absorbent core 40 and can be joined to the garment-facing surface of the absorbent core by an attachment method (not shown) well known in the art. For example, the backsheet 50 can be secured to the absorbent core 40 by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of independent lines, spirals, or dots of adhesive. Alternatively, the attachment method may include the use of thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other suitable attachment method known in the art or combinations of these attachment methods.

[0122] The backsheet 50 may be impermeable or substantially impermeable to liquids (e.g., urine) and may be made of a thin plastic film, although other flexible liquid-impermeable materials can also be used. As used herein, the term "flexible" refers to a material that is compliant and easily conforms to the general shape and contours of the human body. The backsheet 207 can prevent or at least inhibit the exudate absorbed and contained in the absorbent core 205 from wetting the clothing that contacts the incontinence pad 10, such as underwear. However, the backsheet 50 can allow vapor to escape from the absorbent core 40 (i.e., is breathable), although in some cases the backsheet 50 may not be able to allow vapor to escape (i.e., is non-breathable). Thus, the backsheet 50 may include a polymer film such as a thermoplastic film of polyethylene or polypropylene. Suitable materials for the backsheet 50 are, for example, thermoplastic films having a thickness of from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mil). Any suitable backsheet known in the art can be utilized with the present invention.

[0123] The backsheet 50 acts as a barrier to any absorbed body fluid that can pass through the absorbent core 40 to the surface of the clothing, thereby reducing the risk of soiling the underwear or other clothing. Preferred materials are soft, smooth, flexible materials that allow liquids and vapors to pass through, providing softness and conformability for comfort, and are low-noise, thus not generating undesirable sounds upon movement.

[0124] Exemplary backsheets are described in U.S. Patent No. 5,885,265 (Osborn, III) issued on March 23, 1999, U.S. Patent No. 6,462,251 (Cimini) issued on October 8, 2002, U.S. Patent No. 6,623,464 (Bewick-Sonntag) issued on September 23, 2003, or U.S. Patent No. 6,664,439 (Arndt) issued on December 16, 2003. Suitable two-layer or multi-layer breathable backsheets for use herein include those exemplified in U.S. Patent Nos. 3,881,489, 4,341,216, 4,713,068, 4,818,600, European Patent Nos. 203821, 710471, 710472, and 793952.

[0125] Suitable breathable backsheets for use herein include all breathable backsheets known in the art. In principle, there are two types of breathable backsheets, a single-layer breathable backsheet that is breathable and water-repellent, and a backsheet having at least two layers that, when combined, provide both breathability and water-repellency. Suitable single-layer breathable backsheets for use herein include, for example, those described in British Patent Nos. A2184389, A2184390, A2184391, U.S. Patent Nos. 4,591,523, 3,989,867, 3,156,242, and International Publication No. 97 / 24097.

[0126] The backsheet may be a nonwoven web having a basis weight of from about 20 gsm to about 50 gsm. In one embodiment, the backsheet is a relatively hydrophobic 23 gsm spunbond nonwoven web of 4 denier polypropylene fibers available from Fiberweb Neuberger under the name F102301001. The backsheet may be coated with a water-insoluble liquid swellable material as described in U.S. Patent No. 6,436,508 (Ciammaichella) issued on August 20, 2002.

[0127] The backsheet has a side facing the clothing and a side facing the opposite side of the body. The side of the backsheet facing the clothing includes a non-adhesive region and an adhesive region. The adhesive region can be provided by any conventional means. It has generally been found that a pressure-sensitive adhesive functions well for this purpose.

[0128] The absorbent core 40 of the present disclosure can include any suitable shape including, but not limited to, an oval, a discorectangle, a rectangle, an asymmetric shape, and an hourglass shape. For example, in some forms of the present invention, the absorbent core 205 can include a contoured shape, such as a shape where the intermediate region is narrower than the end regions. As yet another example, the absorbent core can include a tapered shape having a wider portion at one end region of the pad and tapering towards the narrower end region at the other end of the pad. The absorbent core 40 can have various stiffnesses in the MD and CD directions.

[0129] The configuration and structure of the absorbent core 40 may vary (e.g., the absorbent core 40 may have varying caliper regions, hydrophilic gradients, superabsorbent gradients, or capture zones of lower average density and lower average basis weight). Further, the dimensions and absorbency of the absorbent core 40 may also be varied to accommodate various wearers. However, the total absorbency of the absorbent core 40 should be compatible with the design load and intended use of the disposable absorbent article or incontinence pad 10.

[0130] In some forms of the present invention, the absorbent core 40 can include a plurality of multifunctional layers in addition to the first and second laminates. For example, the absorbent core 40 can include a core wrap (not shown) useful for surrounding the first and second laminates, as well as any other layers. The core wrap can be formed of two nonwoven materials, a substrate, a laminate, a film, or other materials. In one aspect, the core wrap can include only a single material, substrate, laminate, or other material at least partially wrapped around it.

[0131] The absorbent core 40 of the present disclosure can include one or more adhesives, for example, to assist in immobilizing SAP or other absorbent materials within the first and second laminates.

[0132] Absorbent cores containing a relatively high amount of SAP with various core designs are disclosed in U.S. Patent No. 5,599,335 to Goldman et al., European Patent No. 1,447,066 to Busam et al., International Publication No. 95 / 11652 to Tanzer et al., U.S. Patent Application Publication No. 2008 / 0312622 (A1) to Hundorf et al., and International Publication No. 2012 / 052172 to Van Malderen. These can be used to form a superabsorbent layer.

[0133] Additions to the core of the present disclosure are contemplated. In particular, the addition of potential to a current multi-layer absorbent core is described in U.S. Patent No. 4,610,678, titled "High-Density Absorbent Structures," issued to Weisman et al. on September 9, 1986; U.S. Patent No. 4,673,402, titled "Absorbent Articles With Dual-Layered Cores," issued to Weisman et al. on June 16, 1987; U.S. Patent No. 4,888,231, titled "Absorbent Core Having A Dusting Layer," issued to Angstadt on December 19, 1989; and U.S. Patent No. 4,834,735, titled "High Density Absorbent Members Having Lower Density and Lower Basis Weight Acquisition Zones," issued to Alemany et al. on May 30, 1989. The absorbent core may further comprise an additional layer that mimics a dual-core system containing a capture / distribution core of chemically stiffened fibers positioned over an absorbent storage core, as detailed in U.S. Patent Nos. 5,234,423 and 5,147,345, titled "Absorbent Article With Elastic Waist Feature and Enhanced Absorbency," issued to Alemany et al. on August 10, 1993. These are useful to the extent that they do not negate or compete with these effects of the laminate of the absorbent core described below of the present invention.

[0134] Some examples of suitable absorbent cores 40 that can be used in the absorbent articles of the present disclosure are described in U.S. Patent Application Publication Nos. 2018 / 0098893 and 2018 / 0098891.

[0135] As described above, the absorbent article comprising the fluid management layer of the present disclosure included a storage layer. Referring back to FIGS. 1A and 1B, the storage layer is generally disposed where the absorbent core 40 is described. The storage layer may be configured as described with respect to the absorbent core. The storage layer may contain conventional absorbent materials. In addition to conventional absorbent materials such as creped cellulose wadding, fluffed cellulose fibers, rayon fibers, wood pulp fibers known as air felts, and fabric fibers, the storage layer often includes a superabsorbent material that absorbs fluid to form a hydrogel. Such materials are also known as absorbent gelling materials (AGM) and may be included in particulate form. AGM can typically absorb large amounts of body fluid and hold them under moderate pressure. Synthetic fibers including cellulose acetate, polyvinyl fluoride, polyvinylidene chloride, acrylics (such as Orlon), polyvinyl acetate, insoluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon), polyesters, bicomponent fibers, tricomponent fibers, mixtures thereof, etc. can also be used in the second storage layer. The storage layer can also include a filler material, such as perlite, diatomaceous earth, vermiculite, or other suitable material, that reduces the rewetting problem.

[0136] The storage layer or fluid storage layer may have the absorbent gelling material (AGM) in a uniform distribution or in a non-uniform distribution. The AGM may be in the form of channels, pockets, stripes, cross patterns, swirls, dots, or any other pattern, and can be either two-dimensional or three-dimensional, imaginable by a person. The AGM may be sandwiched between a pair of fibrous cover layers. Or the AGM may be at least partially encapsulated by a single fibrous cover layer.

[0137] A part of the storage layer can be formed of only the superabsorbent material, or can be formed of the superabsorbent material dispersed in a suitable carrier such as fluff-like cellulose fibers or stiffened fibers. A non-limiting example of the storage layer is the first layer formed of only the superabsorbent material disposed on the second layer formed of a dispersion of the superabsorbent material in cellulose fibers.

[0138] Examples of the absorbent core formed by a layer of the superabsorbent material and / or a layer of the superabsorbent material dispersed in cellulose fibers that can be used in the absorbent articles (e.g., sanitary napkins, incontinence products) detailed in the specification are disclosed in U.S. Patent Application Publication No. 2010 / 0228209 (A1). Absorbent cores containing a relatively high amount of SAP with various core designs are disclosed in U.S. Patent No. 5,599,335 to Goldman et al., European Patent No. 1,447,066 to Busam et al., International Publication No. 95 / 11652 to Tanzer et al., U.S. Patent Application Publication No. 2008 / 0312622 (A1) to Hundorf et al., International Publication No. 2012 / 052172 to Van Malderen, U.S. Patent No. 8,466,336 to Carlucci, and U.S. Patent No. 9,693,910 to Carlucci. These can be used to constitute the second storage layer.

[0139] The absorbent core 10 may further include a barrier cuff. Some examples of other suitable barrier cuffs are described in U.S. Patent Nos. 4,695,278, 4,704,115, 4,795,454, 4,909,803, and U.S. Patent Application Publication No. 2009 / 0312730. Further suitable barrier cuffs are described in U.S. Patent Application Publication Nos. 2018 / 0098893 and 2018 / 0098891.

[0140] Additional assumed examples Example A A1: A disposable absorbent article comprising a topsheet, a backsheet, an absorbent core disposed between the topsheet and the backsheet, and an integrated nonwoven fluid management layer disposed between the topsheet and the absorbent core, wherein the absorbent article exhibits an average wicking size of less than about 2400 mm 2 when measured according to the wicking size test method, more preferably less than about 2100 mm 2 when measured according to the wicking size test method, or most preferably less than about 1800 mm 2 when measured according to the wicking size test method, and a difference in capture speed between the second jet and the first jet of less than about 11 seconds, more preferably less than about 9 seconds, or most preferably less than about 8 seconds when measured by the repeated capture and rewetting method. A2: The disposable absorbent article according to Example A1, wherein the absorbent article exhibits an average wicking size of about 1200 mm 2 ~ about 2400 mm 2 when measured according to the wicking size test method, more preferably about 1200 mm 2 ~ about 2100 mm 2 when measured according to the wicking size test method, or most preferably about 1200 mm 2 ~ about 1950 mm 2 when measured according to the wicking size test method. A3: The disposable absorbent article according to Example A1 or A2, wherein the fluid management layer has a basis weight in the range of about 40 gsm to about 75 gsm, more preferably in the range of about 50 gsm to about 70 gsm, or most preferably in the range of about 55 gsm to about 65 gsm. A4: The disposable absorbent article according to any one of Examples A1 to A3, wherein the fluid management layer contains absorbent fibers in the range of about 10 wt% to about 60 wt%, more preferably in the range of about 15 wt% to about 50 wt%, and most preferably in the range of about 20 wt% to about 40 wt%. A5: The disposable absorbent article according to any one of Examples A1 to A4, wherein the fluid management layer contains absorbent fibers in the range of about 20 wt% to about 30 wt%. A6. The disposable absorbent article according to any one of Examples A1 to A5, wherein the fluid management layer contains absorbent fibers having a linear density in the range of about 1 dtex to about 7 dtex, more preferably in the range of about 1.4 dtex to about 6 dtex, or most preferably in the range of about 1.7 dtex to about 5 dtex. The disposable absorbent article according to any one of Examples A1 to A6, wherein the fluid management layer contains elastic fibers in an amount of about 15% to about 70% by weight, more preferably about 20% to about 60% by weight, or most preferably about 25% to about 50% by weight. The disposable absorbent article according to any one of Examples A1 to A7, wherein the fluid management layer contains elastic fibers in an amount of about 25% to about 35% by weight. The disposable absorbent article according to any one of Examples A1 to A8, wherein the fluid management layer contains elastic fibers having a linear density of about 4 dtex to about 15 dtex, more preferably about 5 dtex to about 12 dtex, or most preferably about 6 dtex to about 10 dtex. The disposable absorbent article according to any one of Examples A1 to A9, wherein the fluid management layer contains elastic fibers having a linear density of about 10 dtex. The disposable absorbent article according to any one of Examples A1 to A10, wherein the fluid management layer contains elastic fibers, and the elastic fibers contain polyethylene terephthalate having a hollow spiral structure. The disposable absorbent article according to any one of Examples A1 to A11, wherein the fluid management layer contains stiffening fibers in an amount of about 25% to about 70%, more preferably about 30% to about 60%, or most preferably about 40% to about 55%. The disposable absorbent article according to any one of Examples A1 to A12, wherein the fluid management layer contains stiffening fibers having a linear density of about 1.0 dtex to about 6 dtex, more preferably about 1.5 dtex to about 5 dtex, or most preferably about 2.0 dtex to about 4 dtex. The disposable absorbent article according to any one of Examples A1 to A13, wherein the fluid management layer contains stiffening fibers having a linear density of about 2.2 dtex. The disposable absorbent article according to any one of Examples A1 to A14, wherein the fluid management layer is integrated by hydroentangling or needle punching. The disposable absorbent article according to any one of Examples A1 to A15, wherein the fluid management layer has a caliper factor of at least about 0.13 mm, more preferably at least about 0.15, or most preferably at least about 0.2 mm. A disposable absorbent article according to any one of Examples A1 to A16, wherein the fluid management layer has a caliper factor of about 0.13 mm to about 0.3 mm, or more preferably about 0.14 mm to about 0.25 mm, or most preferably about 0.15 mm to about 0.22 mm. A disposable absorbent article according to any one of Examples A1 to A17, wherein the absorbent article is a menstrual pad.

[0141] Test Method Caliper The caliper or thickness of the test piece is measured as the distance between a reference platform on which the sample is placed and a presser that applies a specific amount of pressure on the sample over a specific time. All measurements are carried out in a laboratory maintained at 23 °C ± 2 °C and a relative humidity of 50% ± 2%, and the test piece is conditioned in this environment for at least 2 hours before the test.

[0142] The caliper is measured with a manual micrometer equipped with a presser that can apply a steady pressure of 0.50 kPa ± 0.01 kPa to the test piece. The manual micrometer is a self-weighted instrument with accurate readings up to 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic available from VWR International, or an equivalent. The presser has a diameter smaller than the test piece and is a flat, grounded, circular movable surface capable of applying the required pressure. A suitable presser has a diameter of 25.4 mm, but smaller or larger pressers can be used depending on the size of the sample being measured. The test piece is supported by a horizontal flat reference platform larger than the surface of the presser and parallel to the surface of the presser. The system is calibrated and operated according to the manufacturer's instructions.

[0143] If necessary, obtain test specimens by removing them from the absorbent article. When excising the test specimens from the absorbent article, take care not to impart any contamination or deformation to the layers of the test specimens during the process. The test specimens are obtained from areas that do not contain folds or wrinkles and must be larger than the presser.

[0144] To measure the caliper, first zero the micrometer against a horizontal flat reference platform. Place the test specimen on the platform with the test position centered under the presser. Gently lower the presser at a descent rate of 3.0 mm ± 1.0 mm / second until the full pressure is applied to the test specimen. After waiting for 5 seconds, record the caliper of the test specimen in 0.001 mm units. Similarly, repeat for a total of 10 replicate test specimens. Calculate the arithmetic mean for all caliper measurements and report it in 0.001 mm units as the caliper.

[0145] Caliper coefficient The caliper coefficient is, as described above, the caliper per 10 gsm of the basis weight of the sample. Thus, the formula is caliper / (basis weight / 10).

[0146] Weighing 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 in accordance with the official method WSP130.1. Cut a piece of the test sample to a known area and measure the mass of the sample using an analytical balance with an accuracy of 0.0001 grams. All measurements are carried out in a laboratory maintained at 23°C ± 2°C and a relative humidity of 50% ± 2%, and the test sample is conditioned in this environment for at least 2 hours before the test.

[0147] The measurement is performed on a test sample taken from a roll or sheet of the raw material, or a test sample obtained from a material layer cut from an absorbent article. When cutting the material layer from the absorbent article, care is taken not to impart any contamination or deformation to the layer during the process. The cut layer shall not contain any residual adhesive. The layer is immersed in a suitable solvent that dissolves the adhesive without adversely affecting the material itself, so that all the adhesive is surely removed. One such solvent is THF (general-purpose tetrahydrofuran available from any convenient source, CAS 109-99-9). After solvent immersion, the material layer is completely air-dried in a manner that prevents unnecessary stretching or other deformation of the material. After the material is dry, test pieces are obtained. The test pieces shall be as large as possible so that any inherent material variations are taken into account.

[0148] Use a NIST-traceable calibrated steel metal gauge or equivalent to measure the dimensions of the single-layer test pieces. Calculate the area of the test pieces and record it in units of 0.0001 square meters. Use an analytical balance to obtain the mass of the test pieces and record it in units of 0.0001 grams. Divide the mass (in grams) by the area (in square meters) to calculate the basis weight and record it in units of 0.01 grams per square meter (gsm). Repeat the test for a total of 10 replicate test pieces in the same manner. Calculate the arithmetic mean of the basis weights and report it in units of 0.01 grams per square meter.

[0149] Composition analysis of the material Determine the quantitative chemical composition of the test pieces containing a mixture of multiple fiber types using ISO 1833-1. All measurements are carried out in a laboratory maintained at 23 °C ± 2 °C and a relative humidity of 50% ± 2%.

[0150] The analysis is performed on test samples taken from rolls or sheets of raw materials, or test samples obtained from material layers cut from absorbent articles. When cutting the material layer from the absorbent article, care is taken not to impart any contamination or deformation to the sample layer during the process. The cut layer shall not contain residual adhesive. The layer is immersed in a suitable solvent that dissolves the adhesive without adversely affecting the material itself so that all the adhesive is surely removed. One such solvent is THF (general-purpose tetrahydrofuran available from any convenient source, CAS 109-99-9). After solvent immersion, the material layer is completely air-dried in such a way as to prevent unwanted stretching or other deformation of the material. After drying the material, test specimens are obtained and tested according to ISO 1833-1 to quantitatively determine its chemical composition.

[0151] Fiber decitex (Dtex) Fabric webs (e.g., woven fabrics, nonwoven fabrics, airlaid) are composed of individual fibers of the material. The fibers are measured with respect to the linear mass density reported in decitex units. The decitex value represents the mass of the fiber in grams present in 10,000 meters of the fiber. The decitex values of the fibers in the material web are often reported by the manufacturer as part of the specifications. If the decitex value of the fiber is not known, the cross-sectional area of the fiber is measured by a suitable microscopy method such as scanning electron microscopy (SEM), and after determining the composition of the fiber using suitable techniques such as FT-IR (Fourier transform infrared) spectroscopy and / or DSC (differential scanning calorimetry), it can be calculated by using the literature values for the density of the composition to calculate the mass of the fiber in grams present in 10,000 meters of the fiber. All tests are carried out in a chamber maintained at a temperature of 23 °C ± 2.0 °C and a relative humidity of 50% ± 2%, and the samples are conditioned under the same environmental conditions for at least 2 hours before the test.

[0152] If necessary, representative samples of the web material of interest can be cut from the absorbent article. In this case, the web material is cut so that the sample is not stretched, distorted, or contaminated.

[0153] Once the SEM image is obtained, analyze it as follows to determine the cross-sectional area of the fiber. To analyze the cross-section of a sample of the web material, prepare a test piece as follows. Cut a test piece of approximately 1.5 cm (height) × 2.5 cm (length) without folds or wrinkles from the web. Immerse the sample in liquid nitrogen and break off the edges along the length of the test piece using a pair of scissors blades (VWR Single Edge Industrial Razor blade No. 9, surgical carbon steel). Sputter coat the test piece with gold and then adhere it to the SEM mount using double-sided conductive tape (Cu, 3M available from electron microscopy sciences). To minimize any oblique distortion of the cross-section being measured, orient the test piece so that the cross-section is as perpendicular as possible to the detector. Obtain the SEM image at a sufficient resolution such that the cross-sections of the fibers present in the test piece are clearly shown. The shapes of the fiber cross-sections vary widely, and some fibers are composed of multiple individual filaments. Nevertheless, the area of each fiber cross-section is measured (e.g., for circular fibers, the diameter; for elliptical fibers, the major and minor axes; for more complex shapes, using image analysis). If the fiber cross-section exhibits a heterogeneous cross-sectional composition, record the area of each recognizable constituent component, calculate the contribution of dtex for each constituent component, and then sum them. For example, if the fiber is a bicomponent fiber, measure the cross-sectional area of the core and sheath separately, calculate the dtex contribution from the core and sheath respectively, and sum them. If the fiber is hollow, exclude the inner portion of the fiber consisting of air that does not significantly contribute to the dtex of the fiber from the cross-sectional area. Overall, perform such measurements of at least 100 cross-sectional areas for each fiber type present in the sample, and record the arithmetic mean a of the cross-sectional areas expressed in square micrometers (μm 2 ) k in units of 0.1 μm 2 .

[0154] The composition of the fibers is determined using common characterization methods such as FTIR spectroscopy. In the case of more complex fiber compositions (such as two-component fibers with a polypropylene core / polyethylene sheath), 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 web material.

[0155] The decitex d of each fiber type in the web material k is calculated as follows. d k = 10000m × a k × ρ k × 10 -6 wherein the unit of d k is grams (per 10,000 meters of calculated length), the unit of a k is μm 2 and the unit of ρ k is grams per cubic centimeter (g / cm 3 ³). The decitex is reported in 0.1 g units (per 10,000 meters of calculated length) together with the fiber type (e.g., PP, PET, cellulose, PP / PET two-component).

[0156] Preparation of Artificial Menstrual Fluid (AMF) Artificial Menstrual Fluid (AMF) is composed of a mixture of defibrinated sheep blood, phosphate buffered saline, and mucus components. AMF is prepared to have a viscosity of 7.15 - 8.65 centistokes at 23 °C.

[0157] The viscosity of the AMF is measured using a low-viscosity rotational viscometer (a suitable instrument is the Cannon LV-2020 Rotary Viscometer equipped with a UL adapter (Cannon Instrument Co., State College, PA) or equivalent). An appropriately sized spindle for the viscosity range is selected and the instrument is operated and calibrated according to the manufacturer's instructions. The measurement is performed at 23 °C ± 1 °C and 60 rpm. The results are reported in centipoise units of 0.01.

[0158] Reagents required for AMF preparation include defibrinated sheep blood having a hematocrit value of 38% or more (collected under aseptic conditions, available from Cleveland Scientific, Inc., Bath, OH, or equivalent), gastric mucin having a target viscosity of 3 to 4 centistokes when prepared as a 2% aqueous solution (crude form, available from Sterilized American Laboratories, Inc., Omaha, NE, or equivalent), 10% v / v aqueous lactic acid solution, 10% w / v aqueous potassium hydroxide solution, dibasic sodium phosphate anhydrous (reagent grade), sodium chloride (reagent grade), monobasic sodium phosphate monohydrate (reagent grade), and deionized water (each available from VWR International or equivalent sources).

[0159] Phosphate Buffered Saline consists of two individually prepared solutions (Solution A and Solution B). To prepare 1 L of Solution A, 1.38 ± 0.005 g of sodium phosphate monobasic monohydrate and 8.50 ± 0.005 g of sodium chloride are added to a 1000 mL volumetric flask, and deionized water is added to volume. Mix thoroughly. To prepare 1 L of Solution B, 1.42 ± 0.005 g of sodium phosphate dibasic anhydrous and 8.50 ± 0.005 g of sodium chloride are added to a 1000 mL volumetric flask, and deionized water is added to volume. Mix thoroughly. To prepare Phosphate Buffered Saline, 450 ± 10 mL of Solution B is added to a 1000 mL beaker and stirred at low speed on a stirring plate. A calibrated pH probe (accurate to 0.1) is inserted into the beaker of Solution B, and sufficient Solution A is added while stirring to bring the pH to 7.2 ± 0.1.

[0160] The mucus component is a mixture of phosphate buffered saline, aqueous potassium hydroxide, gastric mucin, and aqueous lactic acid. The amount of gastric mucin added to the mucus component directly affects the final viscosity of the prepared AMF. To determine the amount of gastric mucin required to obtain AMF within the target viscosity range (7.15 - 8.65 centistokes at 23°C), three batches of AMF with various amounts of gastric mucin in the mucus component are prepared, then a linear fit is performed by the method of least squares passing through three points, and the exact amount required is interpolated from the concentration-versus-viscosity curve. A good range of gastric mucin is usually 38 - 50 grams.

[0161] To prepare approximately 500 mL of mucus component, 460 ± 10 mL of pre-prepared phosphate buffered saline and 7.5 ± 0.5 mL of 10% w / v potassium hydroxide aqueous solution are added to a 1000 mL sturdy glass beaker. This beaker is placed on a stirring hot plate and the temperature is brought to 45°C ± 5°C while stirring. A predetermined amount of gastric mucin (±0.50 g) is weighed and slowly poured into the already prepared liquid at 45°C without agglomeration. Cover the beaker and continue mixing. Over 15 minutes, bring the temperature of this mixture above 50°C but not exceeding 80°C. While maintaining this temperature range, continue heating with gentle stirring for 2.5 hours. After 2.5 hours, remove the beaker from the hot plate and cool it to below 40°C. Next, add 1.8 ± 0.2 mL of 10% v / v lactic acid aqueous solution and mix well. Autoclave the mucus component mixture at 121°C for 15 minutes and let it cool for 5 minutes. Take the mucus component mixture out of the autoclave and stir until the temperature reaches 23°C ± 1°C.

[0162] Bring the temperature of the sheep blood and mucus component to 23°C ± 1°C. Using a 500 mL graduated cylinder, measure the total volume of the pre-prepared mucus component batch and add that volume to a 1200 mL beaker. Add an equal volume of sheep blood to the beaker and mix well. Using the viscosity method described above, confirm that the viscosity of the AMF is between 7.15 and 8.65 centistokes. If not, the batch is discarded, another batch is made, and the mucus components are adjusted as necessary.

[0163] The certified AMF needs to be refrigerated at 4°C unless intended for immediate use. The AMF can be stored in an airtight container at 4°C for a maximum of 48 hours after preparation. Before testing, the AMF needs to be brought to 23°C ± 1°C. After the test is completed, any unused portion is discarded.

[0164] Repeated capture time and rewetting The capture time is measured for an absorbent article administered with the herein-described artificial menses fluid (AMF) using a wicking plate and an electronic circuit interval timer. The time required for the absorbent article to capture a series of doses of AMF is recorded. After the capture test, a rewetting test is performed. All measurements are conducted in a laboratory maintained at 23 °C ± 2 °C and a relative humidity of 50% ± 2%.

[0165] Referring to FIGS. 7-9B, the wicking plate 9001 is composed of plexiglass having overall dimensions of length 10.2 cm × width 10.2 cm × height 3.2 cm. The longitudinal channel 9007 extending along the length of the plate is 13 mm deep and 28 mm wide at the top surface of the plate, and the transverse walls slope downward at 65° to a base 15 mm wide. The central test fluid well 9009 is 26 mm long, 24 mm deep, and 38 mm wide at the top surface of the plate, and the transverse walls slope downward at 65° to a base 15 mm wide. At the base of the test fluid well 9009, there is an "H"-shaped test fluid reservoir 9003 that opens to the bottom of the plate for introducing fluid onto the underlying test sample. 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 3.5 mm apart. The central post has a radius 9011 of 3 mm and houses opposing electrodes 6 mm apart. The sides of the reservoir curve outward in an arcuate shape with a radius 9012 of 14 mm bounded by an overall width 2013 of 15 mm. Two wells 9002 (length 80.5 mm × width 24.5 mm × depth 25 mm) located outside the transverse channel are filled with lead shot (or equivalent) to adjust the overall mass of the plate and provide 0.25 psi (17.6 g / cm 2It provides the confinement pressure. The electrode 9004 is embedded in the plate 9001 and connects the external banana jack 9006 to the inner wall 9005 of the fluid reservoir 9003. The circuit interval timer is plugged into the jack 9006, monitors the impedance between the two electrodes 9004, and measures the time from the introduction of the AMF into the reservoir 9003 until the AMF is discharged from the reservoir. The timer has a resolution of 0.01 seconds.

[0166] For the rewetted portion of the test, the pressure applied to the test sample is 1.0 psi. The rewetted weight is configured such that the dimensions of the bottom surface of the weight match the dimensions of the wetted plate, and the total mass required is calculated to provide a pressure of 1.0 psi over the bottom surface of the weight. Thus, the bottom surface of the weight is 10.2 cm in length × 10.2 cm in width and is composed of a flat, smooth, rigid material (e.g., stainless steel) to provide a mass of 7.31 kg.

[0167] For each test sample, seven filter papers cut to a diameter of 150 mm are used as the rewetted substrate. Prior to the test, the filter papers are conditioned at 23°C ± 2°C and a relative humidity of 50% ± 2% for at least 2 hours. A suitable filter paper has a basis weight of approximately 74 gsm, a thickness of approximately 157 micrometers with a medium porosity, and is available from VWR International as grade 413.

[0168] The test sample is removed from all packaging, taking care not to push or pull the product during handling. No attempt is made to smooth out wrinkles. Prior to testing, the test sample is conditioned at 23 ± 2 °C and 50% ± 2% relative humidity for at least 2 hours. Determine the administration position as follows. For symmetric samples (i.e., the front side of the sample has the same shape and size as the back side when divided laterally along the midpoint of the longitudinal axis of the sample), the administration position is the intersection of the midpoint of the longitudinal axis of the sample and the midpoint of the transverse axis. For asymmetric samples (i.e., the front side of the sample does not have the same shape and size as the back side when divided laterally along the midpoint of the longitudinal axis of the sample), the administration position is the intersection of the midpoint of the longitudinal axis of the sample and the transverse axis located at the midpoint of the wing of the sample.

[0169] The required mass of the soak-through plate needs to be calculated for the specific dimensions of the test sample such that a restraint pressure of 0.25 psi is applied. Measure and record the lateral width of the core at the administration position in 0.1 cm increments. The required mass of the soak-through plate is calculated by multiplying the core width by the length of the soak-through plate (10.2 cm) and multiplying by 17.6 g / cm 2 and is recorded in 0.1 g increments. Add lead shot (or equivalent) to well 9002 in the soak-through plate to achieve the calculated mass.

[0170] Connect an electronic circuit interval timer to soak-through plate 9001 and set the timer to zero. Place the test sample on a flat horizontal surface with the body side facing up. Gently place soak-through plate 9001 over the center of the test sample and confirm that the "H" shaped reservoir 9003 is centered over the predetermined administration position.

[0171] Use a mechanical pipette to accurately pipette 3.00 mL ± 0.05 mL of AMF into the test fluid reservoir 9003. The fluid is dispensed without splashing within a period of 3 seconds or less along the formed lip at the bottom of the reservoir 9003. Immediately after the fluid is captured, record the capture time in 0.01 - second increments and start a 5 - minute timer. Similarly, apply the second and third doses of AMF into the test fluid reservoir with a 5 - minute waiting period between each application. Record the capture time in 0.001 - second increments. Immediately after the third dose of AMF is captured, start a 5 - minute timer and prepare filter paper for the rewetting portion of the test.

[0172] Obtain the mass of 7 filter papers and record it in 0.001 - gram units as Dry Mass fp When 5 minutes have elapsed after the third capture, gently remove the soak - through plate from the test sample and set it aside. Place 7 pre - weighed filter papers on the test sample and center the stack above the dosing position. Here, place the rewetting weight centered above the filter papers and start a 15 - second timer. As soon as 15 seconds have elapsed, gently remove the rewetting weight and set it aside. Obtain the mass of 7 filter papers and record it in 0.001 - gram units as Wet Mass fp Subtract Dry Mass fp from Wet Mass fp and report it in 0.001 - gram units as the rewetting value. Before testing the next sample, thoroughly clean the electrode 9004 and wipe any residual test fluid from the bottom of the soak - through plate and the rewetting weight.

[0173] Immediately after the rewetting portion of the test, proceed to the stain - size method using the administered test sample as described herein.

[0174] Similarly, repeat the entire procedure for 10 replicate samples. The reported values are the arithmetic means of 10 individually recorded measurements in 0.001 - second units for the capture times (first, second, and third) and 0.001 - gram units for the rewetting values.

[0175] Stain - size measurement method This method describes a method for measuring the size of a visible fluid stain on an absorbent article. This procedure is carried out on a test sample immediately after administering a test liquid according to a separate method (e.g., repeated capture and rewetting method) as described herein. The resulting test sample is photographed under controlled conditions. Then, each photographic image is analyzed using image analysis software to obtain a measurement of the size of the visible stain obtained. All measurements are carried out at a constant temperature (23°C ± 2°C) and relative humidity (50% ± 2%).

[0176] With a calibrated ruler (traceable to NIST or equivalent), the test sample is placed horizontally flat on a matte black background within a light box that provides stable, uniform illumination across the entire base of the light box. A suitable light box is the Sanoto MK50 (Sanoto (Guangdong, China)) or equivalent, which provides illumination of 5500 lux at a color temperature of 5500K. A digital single-lens reflex (DSLR) camera with manual setting control (e.g., Nikon D40X available from Nikon (Tokyo, Japan), or equivalent) is placed directly above the opening at the top of the light box such that the entire article and the ruler are visible within the camera's field of view.

[0177] 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, US) or equivalent), the camera's white balance is custom set for the lighting conditions inside the light box. The manual settings of the camera are set so that the image is properly exposed, thereby having no signal clipping in any of the color channels. Suitable settings may be an f / 11 aperture setting, an ISO setting of 400, and a shutter speed setting of 1 / 400 second. At a 35 mm focal length, the camera is placed about 14 inches above the article. The image is properly focused, captured, and saved as a JPEG file. The resulting image should contain the entire test sample and distance scale at a minimum resolution of 15 pixels / mm.

[0178] To analyze the image, it is transferred to a computer running image analysis software (suitable software is MATLAB available from Mathworks, Inc (Natick, MA) or equivalent). The image resolution is calibrated using the calibrated distance scale within the image to determine the number of pixels per millimeter. The image is analyzed by manually drawing the boundaries of the region of interest (ROI) around the visually recognizable outer perimeter of the stain formed by the previously administered test fluid. The area of the ROI is reported as the total stain area in 0.01 mm 2 units, along with notation regarding what method (e.g., repeated capture and rewetting) was used to generate the test sample being analyzed.

[0179] This entire procedure is repeated for all of the replicate test samples generated from the method(s) of administration. The reported value is the average of the measurements individually recorded for the total stain area in 0.01 mm 2 units, along with notation regarding what method (e.g., repeated capture and rewetting) was used to generate the test sample being analyzed.

[0180] Dynamic mechanical analysis Using a dynamic mechanical analyzer (DMA), the compressive resistance and recovery characteristics of specimens obtained from individual materials or portions of absorbent articles are measured. A suitable instrument is the DMA Q800 (available from TA Instruments (New Castle, Delaware)) equipped with a 40 mm diameter compression plate, or equivalent. The specimens are exposed to a series of axial compressive force gradients with a controlled change in stress, and the resulting change in displacement is measured. All tests are conducted in a chamber controlled at 23°C ± 3°C and 50% ± 2% relative humidity.

[0181] Prior to testing, the sample is conditioned at 23°C ± 3°C and 50% ± 2% relative humidity for at least 2 hours. When testing the entire article, if present, the release paper is removed from any panty fastening adhesive on the garment-facing surface of the article. A light coating of talc powder is applied to the adhesive to reduce stickiness. The article is placed on a bench with the body-side surface facing up, and then the test location is identified and marked as follows. For symmetric articles (i.e., the front side of the article is the same shape and size as the back side when the article is divided laterally along the midpoint of the longitudinal axis of the sample), the test location is the intersection of the midpoint of the longitudinal axis of the article and the midpoint of the transverse axis. For asymmetric articles (i.e., the front side of the article is not the same shape and size as the back side when the article is divided laterally along the midpoint of the longitudinal axis of the article), the test location is the intersection of the midpoint of the longitudinal axis of the article and the transverse axis located at the midpoint of the wing of the article. A circular cutting die is used to cut a 40 mm diameter specimen centered at the test location. When testing individual material layers (e.g., raw materials or layers excised from the article), the test location is determined in the same manner as when testing the entire article based on where the individual material is located within the article.

[0182] Program the DMA for a controlled force test with a force ramp from 0.02 N to 10 N at a rate of 25 N / min. The test temperature is ambient (23 °C ± 3 °C), so the furnace remains open. Set the Poisson's ratio to 0.44. The data sampling interval is 0.1 s / point. Collect data over 5 cycles of force ramp, e.g., 5 force ramps from 0.2 N to 10 N and 5 force ramps from 10.00 N to 0.02 N. The initial thickness of the test specimen is recorded by the instrument when the initial applied force is 0.02 N.

[0183] Start the test and collect force (N) and displacement (mm) data for all 5 cycles of force ramp. The first half of the cycle is the compression step (force is being applied to the test specimen), and the second half of the cycle is the recovery step (force is being removed from the test specimen). Calculate the following intermediate results for the test specimen.

[0184]

Table 10

[0185] Here, for each individual force ramp cycle (1 - 5), calculate and report the following parameters.

[0186]

Table 11

[0187] Similarly, repeat for a total of 5 replicate test specimens and report the arithmetic mean of each calculated parameter.

[0188] Liquid penetration time The penetration time is measured for a test sample soiled with a known volume of test liquid using a penetration plate and an electronic circuit interval timer in accordance with the official method WSP70.3. Record the time required for the test liquid to pass through the test sample. All measurements are carried out in a laboratory maintained at 23°C ± 2°C and a relative humidity of 50% ± 2%, and the test sample is conditioned in this environment for at least 2 hours before the test.

[0189] The materials required to conduct this test are as follows. The test liquid is 0.9% saline (prepared by weighing 9.0 g ± 0.05 g of reagent grade NaCl in a flat-bottom boat and transferring it to a 1 L volumetric flask and diluting to volume with deionized water). The standard absorbent pad placed under the test sample consists of five layers of Ahlstrom Grade 989 filter paper cut to 10 cm × 10 cm (available from Ahlstrom-Munksjo North America LLC (Alpharetta, GA)), or equivalent. The penetration plate and the electronic circuit interval timer are described in the WSP method and can be purchased from W. Fritz Mezger, Inc (Spartanburg, SC) as the Lister AC Strikethrough Tester.

[0190] The measurement is carried out on a test sample taken from a roll or sheet of raw material cut to a size of 10 cm × 10 cm. The measurement can also be carried out on a test sample obtained from a material layer removed from an absorbent article. When cutting the material layer from the absorbent article, care should be taken not to impart any contamination or deformation to the sample layer during the process. If the material layer is cut from the absorbent article, the test position must be determined and marked as follows. In the case of a symmetric article (i.e., the front side of the article has the same shape and size as the back side when divided laterally along the midpoint of the longitudinal axis of the article), the test position is the intersection of the midpoint of the longitudinal axis of the article and the midpoint of the transverse axis. In the case of an asymmetric sample (i.e., the front side of the article does not have the same shape and size as the back side when divided laterally along the midpoint of the longitudinal axis of the article), the test position is the intersection of the midpoint of the longitudinal axis of the article and the transverse axis located at the midpoint of the wing of the article. In this case, the entire layer cut from the absorbent article is the test sample and is not cut to a specific size. In this case, it is possible for the width of the test sample to be less than 10 cm, but it must be wide enough at the test position to completely cover the opening of the wicking plate.

[0191] The test sample is placed on the filter paper with the side intended to face the wearer's body facing up and the test position centered at the midpoint of the filter paper. Then, the wicking plate is centered over the test sample and the filter paper, and the test is performed according to WSP70.3. Only a single ejection of the test liquid is applied, and the wicking time is recorded in 0.01-second increments.

[0192] Similarly, the test is repeated for five replicate test samples using a new stack of filter paper for each replicate. The wicking time is calculated and reported in 0.01-second increments as the arithmetic mean of the replicates.

[0193] Wet CD Flexibility Wet CD flexibility is a measure of the force required to deform an absorbent article loaded with a known volume of Paper Industry Fluid (PIF) as described herein, using a periodic compression test against a constant velocity directed horizontally by a tensile testing machine having a computer interface. The test consists of 7 cycles of load application and load removal, and calculates the average hysteresis area (flexibility), the average initial slope (initial stiffness), and the average total slope (total stiffness) of the force-displacement curve over the last 3 cycles. All tests are conducted in a room controlled at 23 °C ± 3 °C and 50% ± 2% relative humidity.

[0194] The tensile testing machine comprises a load frame consisting of two guide profiles, two lead screws, and two moving crossheads (each mounted opposite each other). The crossheads are symmetrically driven in opposite directions by two lead screws with precision ball screws having no play, guided by linear guides via two carriages on ball bearings. A suitable instrument can be purchased from Zwick Roell (Ulm, Germany) as item D0724788. Calibrate and operate the instrument according to the manufacturer's instructions. Attach a single load cell, where the measured force is within 10% - 90% of the cell's limit, to one of the moving crossheads. The tensile testing machine is equipped with an identical set of rounded edge grips used to hold the test sample, one attached to the right moving crosshead and the other to the left moving crosshead, both centered with the tensile axis of the tensile testing machine. The rounded edge grips have a hemispherical shape with a radius of 50 mm and are configured to firmly grip the test sample to prevent slippage. Such grips are available from Zwick Roell (Ulm, Germany). The right and left grips are attached in such a way that they are aligned horizontally and vertically.

[0195] The tensile tester is programmed for compression testing to collect force (N) and displacement (mm) data at an acquisition rate of 50 Hz as the crosshead moves at a rate of 150 mm / min. The gauge length is set to 55 mm (separation between the outermost edges of the hemispherical grips) and the path length is 20 mm. The compression test consists of seven force cycles. In the first cycle, the grips move from a starting separation distance of 55 mm to a separation distance of 35 mm, then return to a separation distance of 50 mm. For each of the subsequent six cycles, the grips move from a separation distance of 50 mm to 35 mm (force application) and then return to a separation distance of 50 mm (force removal).

[0196] In this test, a strip of standard cotton is secured to the garment side of the test specimen to cover the Panty Fastening Adhesive (PFA). The standard cotton is approximately 100 g / m2, available from Testfabrics, Inc. (West Pittston, PA). 2 The fabric is a bleached 100% cotton weave (Style #429W). Additional vendors of this fabric can be found on the Testfabrics website, www.testfabrics.com. In this experiment, the laterality of the cotton is not relevant. Prepare standard cotton strips having a width of 76 mm and a length of approximately 200 mm. Use a new cotton strip for each test sample.

[0197] Before the test, the test article is conditioned at 23°C ± 2°C and a relative humidity of 50% ± 2% for at least 2 hours. To prepare the test specimen, first remove it from any packaging material present. If the specimen is folded, gently unfold it and smooth out any wrinkles. If wings are present, unfold them, leaving the release paper in place. Place the specimen on a flat, rigid horizontal surface with the clothing side up and the wings extended. Remove the PFA protective cover from the back of the specimen. With the specimen under tension, center a standard cotton strip over the back of the specimen (aligning both longitudinal axes) and secure it to the PFA without creating any wrinkles in either the cotton strip or the specimen. Ensure good contact exists between the cotton strip and the specimen with light pressure. Here, remove the release paper from the wings, fold the wings around the lateral edges of the cotton strip, and gently secure them to the cotton. Take care not to impart strain or compression to the specimen during cotton attachment. Flip the specimen and attached cotton cover so that the body side of the specimen is facing up. Here, determine and mark the application position as follows. Mark a region 40 mm in length (aligned with the longitudinal axis of the specimen) by 30 mm in width (aligned with the transverse axis of the specimen) centered at the intersection of the midpoints of the longitudinal and transverse axes of the specimen.

[0198] Administer the test liquid to the specimen as follows. Using a mechanical pipette, load the test specimen with PIF. Dispense 7.5 mL of PIF accurately and uniformly over the entire pre-marked application position within 5 seconds without splashing. Start a 10-minute timer as soon as the PIF is dispensed from the pipette. Ensure, as described above, that the tensile testing machine is programmed and the grips are 55 mm apart. After 10 minutes have elapsed, insert the side of the test specimen into the grips of the tensile testing machine, ensuring that the specimen is centered at the application position in both the longitudinal and transverse directions. The transverse axis of the test specimen at the longitudinal midpoint is precisely aligned with the central tensile axis of the tensile testing machine. Zero the load cell and start a cyclic compression test, collecting force (N) and displacement (mm) data for all 7 cycles of force application and force removal.

[0199] Create a graph of force (N) versus displacement (mm) for the last 3 cycles (cycles 5 - 7). Calculate the area of the hysteresis loop (the total area formed between load application and load removal) for each of the 3 cycles, and record it in units of 0.01 N * mm. Here, calculate the average area over all 3 cycles and record it in units of 0.01 N * mm as the wet CD flexibility. For each of the 3 cycles, determine the initial slope of the line between displacement values of 5.25 mm to 5.50 mm (during the load application part of the cycle) and record it in units of 0.1 N / m. Here, calculate the average initial slope over all 3 cycles and record it in units of 0.1 N / mm as the initial stiffness. For each of the 3 cycles, determine the total slope of the line between the point where the minimum force occurs (from the load application part of the cycle) and the point where the maximum force occurs (from the load removal part of the cycle), and record it in units of 0.1 N / m. Here, calculate the average total slope over all 3 cycles and record it in units of 0.1 N / mm as the total stiffness.

[0200] Similarly, repeat the test for a total of 10 replicate test samples. Calculate the arithmetic mean of the wet CD flexibility and report it in units of 0.01 N * mm. Calculate the arithmetic mean of the wet CD initial stiffness and report it in units of 0.1 N / m. Calculate the arithmetic mean of the wet CD total stiffness and report it in units of 0.1 N / m.

[0201] Preparation of Papermaking Industry Fluid (PIF) Paper Industry Fluid (PIF) is a widely accepted non-blood-based surrogate fluid for human blood that is harmless. PIF is an aqueous mixture consisting of sodium chloride, carboxymethylcellulose, glycerol, and sodium bicarbonate, and its surface tension is adjusted by the addition of a non-ionic surfactant. This standard test fluid was developed by the technical committee of the French industrial group of manufacturers of physiological products (Groupment Francaise de producteurs d’articles pour usage sanitaires et domestiques) and is described in the AFNOR standard, Normilization francaise Q34-018 in September 1994. When properly prepared, PIF has a viscosity of 11 ± 1 centipoise, a surface tension of 50 ± 2 mN / m, and a pH value of 8 ± 1 at a temperature of 23°C ± 1°C.

[0202] The viscosity of the prepared PIF is measured using a low-viscosity rotational viscometer (a suitable instrument is the Cannon LV-2020 Rotary Viscometer equipped with a UL adapter (Cannon Instrument Co. (State College, PA)) or equivalent). A spindle of the appropriate size for the viscosity range is selected, and the instrument is operated and calibrated according to the manufacturer's instructions. The measurement is carried out at 23°C ± 1°C and 30 rpm. The results are reported in units of 0.1 centipoise.

[0203] The surface tension of the prepared PIF is measured using a tensiometer. A suitable instrument is the Kruss K100 with the plate method (available from Kruss GmbH (Hamburg, Germany)) or equivalent. This instrument is operated and calibrated according to the manufacturer's instructions. The measurement is taken when the aqueous mixture is at a temperature of 23°C ± 1°C. The results are reported in units of 0.1 mN / m.

[0204] Reagents required for PIF preparation include sodium chloride (reagent grade solid), carboxymethyl cellulose (>98% purity, mass fraction), glycerol (reagent grade liquid), sodium bicarbonate (reagent grade solid), a 0.25 wt% aqueous solution of polyethylene glycol tert-octylphenyl ether (Triton™ X-100, reagent grade), and deionized water. Each reagent is available from VWR International or an equivalent source.

[0205] The following preparation process yields approximately 1 liter of PIF. Add 80.0 ± 0.01 g of glycerol to a 2 L glass beaker. Since the amount of carboxymethyl cellulose (CMC) directly affects the final viscosity of the prepared PIF, the amount of CMC is adjusted to yield a final viscosity within the target range (11 ± 1 centipoise). While stirring, slowly add carboxymethyl cellulose to the beaker of glycerol (in an amount of 15 - 20 grams) to minimize aggregation. Continue stirring for about 30 minutes or until all of the CMC is dissolved and no lumps remain. At this point, add 1000 ± 1 g of deionized water to the beaker and continue stirring. Next, while stirring, add 10.0 ± 0.01 g of sodium chloride and 4.0 ± 0.01 g of sodium bicarbonate to the beaker. Since the amount of the nonionic surfactant solution (0.25 wt% Triton™ X-100 aqueous) directly affects the final surface tension of the prepared PIF, the amount of 0.25 wt% Triton™ X-100 is adjusted to yield a final surface tension within the target range (50 ± 2 mN / m). The total amount of 0.25 wt% Triton X-100 solution to be added to the beaker is approximately 3.7 mL.

[0206] Ensure that the temperature of the prepared PIF is 23°C ± 1°C. Using the viscosity and surface tension methods described above, ensure that the viscosity is 11 ± 1 centipoise and the surface tension is 50 ± 2 mN / m. Measure the pH of the prepared PIF using a pH strip or pH meter (any convenient source) and ensure that the pH is within the target range (8 ± 1). If a batch of the prepared PIF does not meet the specified target, it is discarded and the amounts of CMC and 0.25 wt% Triton™ X-100 solution are adjusted as necessary to make another batch.

[0207] Batches of qualified PIF are stored covered at 23°C ± 1°C. Viscosity, surface tension, and pH are tested daily before use to ensure that the mixture meets the specified targets for each parameter.

[0208] MD Bend Length The MD bend length measurements provided herein were obtained by using Worldwide Strategic Partners (WSP) Test Method 90.1.

[0209] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise indicated, each such dimension is intended to mean both the recited value and the functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".

[0210] All documents cited in this specification, including any cross-references or related patents or patent applications, are hereby incorporated by reference in their entirety herein, unless expressly excluded or otherwise limited. The citation of any document is not to be construed as an admission that it is prior art with respect to any invention disclosed or claimed in this specification, or that it alone, or in combination with any other reference or references, teaches, suggests, or discloses any such invention. Further, in the event that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition given to the term in this document shall apply.

[0211] Although 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. Accordingly, it is intended that all such changes and modifications within the scope of the invention be covered by the appended claims.

Claims

Claim 1 A disposable absorbent article comprising a topsheet, a backsheet, an absorbent core disposed between the topsheet and the backsheet, an integrated nonwoven fluid management layer disposed between the topsheet and the absorbent core, wherein the absorbent article exhibits an average capture rate for a first jet of 5 seconds to 13 seconds, more preferably 5 seconds to 12 seconds, or most preferably 5 seconds to 11 seconds when measured according to the repeated capture and rewetting method, and the fluid management layer has a basis weight in the range of 40 gsm to 75 gsm when measured by the basis weight method, 10 wt% to 60 wt% absorbent fibers, 15 wt% to 70 wt% elastic fibers, and 25 wt% to 70 wt% stiffening fibers when measured by material composition analysis, and the weight percentage of the stiffening fibers is greater than or equal to the weight percentage of the elastic fibers, the integrated nonwoven fluid management layer; and a disposable absorbent article. Claim 2 The disposable absorbent article according to claim 1, wherein the absorbent article exhibits an average capture rate for a second jet of 9 seconds to 23 seconds, more preferably 9 seconds to 21 seconds, or most preferably 9 seconds to 18 seconds when measured according to the repeated capture and rewetting method. Claim 3 The disposable absorbent article according to claim 1 or 2, wherein the absorbent article exhibits an average capture rate for a third jet of 15 seconds to 31 seconds, more preferably 15 seconds to 29 seconds, or most preferably 15 seconds to 27 seconds when measured according to the repeated capture and rewetting method. Claim 4 The disposable absorbent article according to any one of claims 1 to 3, wherein the absorbent article exhibits an average capture rate of less than 13 seconds, more preferably less than 12 seconds, or most preferably less than 11 seconds for the first jet when measured according to the repeated capture and rewetting method. Claim 5 The disposable absorbent article according to claim 2, wherein the absorbent article exhibits an average capture rate of less than 23 seconds for the second jet, more preferably less than 21 seconds for the second jet, or most preferably less than 18 seconds for the second jet when measured according to the repeated capture and rewetting method. Claim 6 The disposable absorbent article according to claim 3, wherein the absorbent article exhibits an average capture rate of less than 31 seconds for the third jet, more preferably less than 29 seconds for the third jet, or most preferably less than 27 seconds for the third jet when measured according to the repeated capture and rewetting method. Claim 7 The disposable absorbent article according to any one of claims 1 to 6, when measured according to the repeated capture and rewetting method, exhibits an average rewetting value of 0.1 gram to 1.0 gram, more preferably 0.1 gram to 0.9 gram, or most preferably 0.1 gram to 0.8 gram.

8. The disposable absorbent article according to claim 7, when measured according to the repeated capture and rewetting method, exhibits an average rewetting value of less than 1.0 gram, more preferably less than 0.9 gram, or most preferably less than 0.8 gram.

9. The disposable absorbent article according to any one of claims 1 to 8, wherein the fluid management layer has a basis weight in the range of 50 gsm to 70 gsm, or most preferably in the range of 55 gsm to 65 gsm.

10. The disposable absorbent article according to any one of claims 1 to 9, wherein the fluid management layer contains 15 wt% to 50 wt% of absorbent fibers, most preferably 20 wt% to 40 wt% of absorbent fibers.

11. The disposable absorbent article according to any one of claims 1 to 10, wherein the fluid management layer contains absorbent fibers having a linear density of 1 dtex to 7 dtex, more preferably 1.4 dtex to 6 dtex, or most preferably 1.7 dtex to 5 dtex.

12. The disposable absorbent article according to any one of claims 1 to 11, wherein the fluid management layer contains 20 wt% to 60 wt% of elastic fibers, or most preferably 25 wt% to 50 wt% of elastic fibers.

13. The disposable absorbent article according to any one of claims 1 to 12, wherein the fluid management layer contains elastic fibers having a linear density of 4 dtex to 15 dtex, more preferably 5 dtex to 12 dtex, or most preferably 6 dtex to 10 dtex.

14. The disposable absorbent article according to any one of claims 1 to 13, wherein the fluid management layer contains elastic fibers having a linear density of 10 dtex.

15. The disposable absorbent article according to any one of claims 1 to 14, wherein the fluid management layer contains 30 wt% to 60 wt% of stiffening fibers, or most preferably 40 wt% to 55 wt% of stiffening fibers.

16. The disposable absorbent article according to any one of claims 1 to 15, wherein the fluid management layer contains stiffening fibers having a linear density of 1.0 dtex to 6 dtex, more preferably 1.5 dtex to 5 dtex, or most preferably 2.0 dtex to 4 dtex. Claim 17 The disposable absorbent article according to any one of claims 1 to 16, wherein the fluid management layer is spunlaced. Claim 18 The disposable absorbent article according to any one of claims 1 to 17, wherein the fluid management layer has a caliper of at least 0.13 mm, more preferably at least 0.15 mm, or most preferably 0.2 mm. Claim 19 The disposable absorbent article according to any one of claims 1 to 18, wherein the fluid management layer has a caliper of 0.13 mm to 0.3 mm, more preferably 0.14 mm to 0.25 mm, or most preferably 0.15 mm to 0.22 mm.

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