Nonwoven fabric and absorbent article containing the same

Abstract

An absorbent article comprising a liquid permeable topsheet, a liquid impermeable backsheet, an absorbent core disposed between the topsheet and the backsheet, and an intermediate layer disposed between the topsheet and the absorbent core, wherein the intermediate layer comprises a nonwoven comprising a plurality of apertures, absorbent fibers, and microfibers, wherein the nonwoven comprises from about 3% to about 35% microfibers by weight of the nonwoven, and the apertures have a hydraulic diameter in the range of from about 600 pm to about 4500 pm; or wherein the absorbent fibers are staple fibers having a fiber length of not less than about 30 mm, and the nonwoven has an air permeability of not less than about 110 m 3 / m 2 / min as measured by the Air Permeability Test and a wicking rate of not less than about 120 mm @ 300 s as measured by the Wicking Rate Test; or wherein the nonwoven has a fiber intermingling degree of not less than about 0.040 as measured by the Fiber Intermingling Degree Test disclosed herein.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to nonwovens suitable for use in disposable absorbent articles, particularly fluid management substrates, which are hydroentangled nonwovens comprising absorbent fibers and microfibers having improved performance characteristics, and to absorbent articles comprising the same. BACKGROUND

[0002] Disposable absorbent articles such as baby diapers, feminine hygiene articles, and incontinence articles are designed to absorb fluids from the body of the wearer. It is desirable in absorbent articles for the body fluid discharged on the topsheet to quickly transfer from the top surface of the topsheet toward the bottom of the topsheet, which is typically held in close contact with the absorbent core of the absorbent article, so that the body fluid quickly transfers from the topsheet into the absorbent core without giving the wearer an uncomfortable wet feeling.

[0003] Disposable absorbent articles are typically designed to include a liquid permeable topsheet, a liquid impermeable backsheet, and an absorbent core disposed between the topsheet and the backsheet. To avoid hindering the transfer of liquid from the topsheet to the absorbent core and to minimize the amount of body fluid retained on the topsheet, absorbent articles have been designed by introducing an acquisition-distribution system ("ADS") between the topsheet and the absorbent core. One desirable function of the ADS is to quickly acquire liquid or other body exudates and transfer them to the absorbent core in an efficient manner. Another function is to reduce the amount of liquid in the topsheet to avoid a wet feeling. To reduce the amount of liquid in the topsheet, the ADS material is required to have good wicking properties to distribute the liquid along the planar direction of the ADS material, thereby reducing the concentration of liquid at the point of loading, and high capillary forces to draw the liquid from the topsheet. Small pore diameters in the planar direction or z-direction contribute to both wicking properties and capillary forces. While small size pores in the ADS enhance wicking properties and capillary forces, they also bring high flow resistance for liquid to penetrate the ADS, which results in slow acquisition speed.

[0004] Some absorbent articles currently marketed include an ADS comprising a nonwoven layer comprising synthetic fibers and / or water-absorbing fibers.

[0005] There is a continuing need for an ADS that quickly moves fluid away from the body while it can reduce the amount of liquid retained in the topsheet in the absorbent article. SUMMARY

[0006] The present invention relates to an absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable backsheet, an absorbent core disposed between the topsheet and the backsheet, and an intermediate layer disposed between the topsheet and the absorbent core, the intermediate layer comprising a nonwoven, wherein the nonwoven comprises a plurality of open holes, absorbent fibers, and from about 3% to about 35% by weight of the nonwoven of microfibers, and wherein the open holes have a hydraulic diameter in the range of from about 600 μm to about 4500 μm.

[0007] The present invention also relates to an absorbent article comprising a liquid permeable topsheet, a liquid impermeable backsheet, an absorbent core disposed between the topsheet and the backsheet, and an intermediate layer disposed between the topsheet and the absorbent core, the intermediate layer comprising a nonwoven, wherein the nonwoven comprises a plurality of open holes, absorbent fibers, and microfibers, wherein the absorbent fibers are staple fibers having a fiber length of not less than about 30 mm, and wherein the nonwoven has an air permeability of not less than about 110 mm as measured by an air permeability test. 3 / m 2 The present invention also relates to a nonwoven fabric comprising a plurality of open pores, absorbent fibers, and about 3% to about 35% by weight of the nonwoven of microfibers, wherein the open pores have a hydraulic diameter in the range of about 600 μm to about 4500 μm.

[0008] The present invention also relates to a nonwoven fabric comprising a plurality of open pores, absorbent fibers, and microfibers, wherein the nonwoven fabric has an air permeability of not less than 110 m / s as measured by an air permeability test. 3 / m 2 / min and an air permeability of not less than about 120 mm@300 s as measured by the wicking rate test. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] While the specification concludes with claims that particularly point out and distinctly claim the subject matter regarded as the invention, it is believed that the invention will be more fully understood from the following description taken in conjunction with the accompanying drawings. Some of the figures may have been simplified by omitting selected elements in order to more clearly illustrate other elements. Such omissions of elements in certain figures do not necessarily indicate the presence or absence of a particular element in any exemplary embodiment unless such is expressly stated in the corresponding caption. The drawings are not drawn to scale.

[0010] Figure 1 is a schematic plan view of an exemplary absorbent article according to the present invention.

[0011] Figure 2 For the Figure 1 2-2 is a side cross-sectional view of the absorbent article.

[0012] Figure 3 is a microscopic image of the nonwoven of the present invention.

[0013] Figure 4 is a microscopic image of another nonwoven of the present invention.

[0014] Figure 5 is a SEM image of a plan view of a nonwoven fabric of the present invention (sample 6).

[0015] Figure 6 is with Figure 5 Magnified SEM image of a plan view of the same nonwoven.

[0016] Figure 7A and Figure 7B 2 is a diagram showing an exemplary cross-sectional shape of a split-film conjugate fiber.

[0017] Figure 8 Schematic diagram of an apparatus for forming openings in a nonwoven fabric.

[0018] Figure 9A is an SEM image of a cross-sectional view of a nonwoven fabric from which the fiber mixing degree was calculated according to the fiber mixing degree test.

[0019] Figure 9B is based on Figure 9A Generated binary image of manually labeled absorption fibers.

[0020] Figure 9C is based on Figure 9A Generated binary image of manually labeled microfibers.

[0021] Figures 10A to 10C is a schematic diagram of an exemplary apparatus for sample preparation and for fluid collection time and amount of liquid in the topsheet.

[0022] Figure 11 is a SEM image of a cross-sectional view of the nonwoven of the present invention (Sample 5).

[0023] Figure 12 is a SEM image of a cross-sectional view of a nonwoven of the present invention (Sample 6).

[0024] Figure 13 is a SEM image of a cross-sectional view of the nonwoven of the present invention (Sample 10).

[0025] Figure 14 is a SEM image of a cross-sectional view of the nonwoven (Sample 15).

[0026] Figure 15 is a SEM image of a cross-sectional view of the nonwoven (Sample 26). DETAILED DESCRIPTION

[0027] Various non-limiting forms of the present disclosure will now be described in order to provide an overall understanding of the structural principles, functioning, manufacture, and use of absorbent articles including back ears having unique engineered strain properties and low surface roughness. One or more examples of these non-limiting embodiments are shown in the drawings. Those skilled in the art will appreciate that the absorbent articles described herein and shown in the drawings are non-limiting example forms and that the scope of the various non-limiting forms of the present disclosure is defined completely by the claims. Features shown or described in connection with one non-limiting form can be combined with the features of other non-limiting forms. Such modifications and variations are intended to be included within the scope of the present disclosure.

[0028] "Absorbent article" refers to a wearable device that absorbs and contains liquid, and more specifically, a device that is placed against or in proximity to the body of a wearer for absorption and containment of the various exudates discharged by the body. Absorbent articles can include diapers, training pants, adult incontinence undergarments, feminine hygiene products such as sanitary napkins and panty-liners, and wipes.

[0029] As used herein, the term "absorbent fiber" is intended to include fibers having a moisture pick-up of no less than about 8%.

[0030] As used herein, the term "comprising" means that various components, ingredients, or steps, which are non-limiting, can be conjointly employed in the processes and methods described herein. Accordingly, the term "comprising", or variations thereof, such as "comprise" and "comprises", is inclusive or open-ended and does not exclude additional, unrecited components, ingredients, or steps.

[0031] As used herein, the term "cellulose-based fiber" is intended to include natural cellulose fibers, such as pulp and cotton, as well as regenerated cellulose fibers, such as rayon (including viscose, lyocell, modal (a product of Lenzing AG, Lenzing, Austria), and cupro), unless otherwise indicated.

[0032] As used herein, the terms "hydrophilic" and "hydrophobic" have the meanings generally accepted in the art with respect to the contact angle of water on a material surface. Thus, a material having a water contact angle greater than about 90° is considered to be hydrophobic, and a material having a water contact angle less than about 90° is considered to be hydrophilic.

[0033] As used herein, the term "natural fiber" refers to elongated substances produced by plants and animals, and includes animal-based fibers and plant-based fibers. Natural fibers can include fibers that are harvested without any post-harvest processing steps, as well as fibers with post-processing steps, such as, for example, washing, scouring, and bleaching.

[0034] As used herein, the term "plant-based fiber" includes both harvested fibers and synthetic fibers comprising a bio-based content. Harvested plant-based fibers can include cellulosic materials such as wood pulp; seed hairs such as cotton; stem (or bast) fibers such as flax and hemp; leaf fibers such as sisal; and husk fibers such as coconut.

[0035] The term "Z-direction" means orthogonal to both the longitudinal and transverse directions.

[0036] Absorbent article

[0037] Absorbent articles will now be generally discussed and further illustrated in the form of a baby diaper 20, as Figure 1 is exemplarily presented. Figure 1 is presented in a plan view of an exemplary diaper 20 in a flat out configuration with the taped end open and the garment facing side turned inside out. A closed article such as a training pant presented to a user can also be laid flat by cutting along its side waist portions. The absorbent article generally has a front edge 110, a back edge 112, and longitudinally extending lateral side edges 113, 114. The front edge 110 forms the edge of the front waist portion and the back edge 112 forms the edge of the back waist portion which together form an opening for the wearer's waist when worn by a wearer. The lateral edges 113, 114 can each form one leg opening. The absorbent article 20 notionally includes a longitudinal centerline 80 dividing the article into left and right sides and a vertical transverse centerline 90 disposed at half the length of the article as measured on the longitudinal centerline 80, where the two centerlines intersect at a center point C. The taped back end 42 is attached to the front of the diaper such as landing zone 44.

[0038] Other layers of the absorbent article are better shown in Figure 2 which, in addition to showing the liquid permeable topsheet 24 and the backsheet 26 in cross-section, also shows the absorbent core 28 positioned between the topsheet 24 and the backsheet 26.

[0039] An optional acquisition and / or distribution layer (or system) 50 is shown in Figure 2 along with other typical diaper components. The acquisition and / or distribution layer can comprise one layer or more than one layer. The acquisition and / or distribution layer can generally not contain SAP as this can slow the acquisition and distribution of fluid, but additional layers can also contain SAP if a certain degree of fluid retention properties is desired.

[0040] The absorbent article can generally include a pair of partially standing barrier leg cuffs 34 having elastic elements 35 and an elasticized gasketing cuff 32 having elastic elements 33 that are substantially co-planar with the chassis. Generally, both types of cuffs are generally joined to the chassis of the absorbent article via bonding to the topsheet and / or the backsheet.

[0041] The absorbent article may include elasticized back ears 40 having taped ends 42 that may be attached to a landing zone 44 at the front of the article, and front ears 46 typically found in such taped diapers.

[0042] Top sheet

[0043] refer to Figure 1 and Figure 2 The topsheet 24 is the portion of the absorbent article 10 that contacts the wearer's skin. The topsheet 24 may be joined to portions of the backsheet 26, the absorbent core 28, the barrier leg cuffs 34, and / or any other layer known to those of ordinary skill in the art. The topsheet 24 can be compliant, soft-feeling, and non-irritating to the wearer's skin. In addition, at least a portion or all of the topsheet 24 can be liquid permeable, allowing liquid body exudates to easily penetrate its thickness.

[0044] The topsheet may comprise a single layer or more than one layer.The topsheet may comprise a plurality of three-dimensional elements, such as protrusions, recesses, apertures and any combination thereof, such that the topsheet has a three-dimensional structure.

[0045] Suitable topsheets can be made from a variety of different materials, such as porous foams, reticulated foams, open-cell plastic films, woven materials, nonwoven materials, woven or nonwoven materials of natural fibers (e.g., wood fibers or cotton fibers), synthetic fibers or filaments (e.g., polyester fibers or polypropylene fibers or PE / PP bicomponent fibers or mixtures thereof), or a combination of natural and synthetic fibers.

[0046] The top sheet may comprise a nonwoven fabric comprising cellulose-based fibers. The top sheet may comprise a nonwoven layer comprising, by weight of the nonwoven layer, between about 20% to about 100%, between about 50% to about 100%, or between about 65% to 100% cellulose-based fibers. The top sheet may comprise approximately 100% cellulose-based fibers, such as approximately 100% cotton fibers. The top sheet may comprise a laminate comprising a nonwoven layer comprising cellulose-based fibers.

[0047] Absorbent core

[0048] As used herein, the term "absorbent core" refers to a component that is used or intended to be used in an absorbent article and that includes absorbent material and an optional core wrap. As used herein, the term "absorbent core" excludes the topsheet, backsheet, and any acquisition-distribution layer or multi-layer system that is not an integral part of the absorbent core. The absorbent core is typically the component of an absorbent article that has the largest absorption capacity of all the components of the absorbent article. The terms "absorbent core" and "core" are used interchangeably herein.

[0049] See also Figure 1 andFigure 2 , the absorbent core 28 can absorb and contain liquids received by the absorbent article and includes absorbent material 60, which can be cellulose fibers, a blend of superabsorbent polymers and cellulose fibers, pure superabsorbent polymers and / or high internal phase emulsion foam. The absorbent core 28 may include channels 29 that do not contain absorbent material, through which the top side 56 of the core wrap can be bonded to the bottom side 58 of the core wrap. The core wrap bond 27 can persist at least while the absorbent core 28 absorbs liquid and swells, and creates a three-dimensional channel at the wearer-facing surface of the article. Of course, this is entirely optional, and the absorbent core may also have no bonded channels, or even no unbonded channels. The absorbent material defines an absorbent material area 8, which may be rectangular, such as Figure 1 As shown, it is also common to have a profiled area that tapers in an area about the transverse centerline 90 .

[0050] The absorbent material includes liquid-absorbent materials commonly used in disposable absorbent articles, such as comminuted wood pulp (commonly referred to as airfelt or fluff). Other examples of suitable liquid-absorbent materials include creped cellulose wadding; meltblown polymers, including coform meltblown polymers; chemically stiffened, modified, or crosslinked cellulose fibers; tissue (including tissue wraps and tissue laminates), absorbent foams, absorbent sponges, superabsorbent polymers (abbreviated herein as "SAP"), absorbent gelling materials, or any other known absorbent material or combination of materials.

[0051] The absorbent material in the absorbent core can be of any type. It can be an air felt core comprising lignocellulosic fibers such as pulp fibers mixed with SAP, or an air felt-free core that does not contain such cellulose fibers. The air felt core typically contains 40% to 80% SAP. For absorbent cores comprising a relatively high proportion of SAP at least partially encapsulated in a core wrap, the SAP content can specifically represent at least 80%, 85%, 90%, 95% and up to 100% superabsorbent polymer by weight of the absorbent material. By weight of the absorbent material, the absorbent material can specifically contain no or only a small amount of cellulose fibers, such as less than 20%, specifically less than 10%, 5% or even 0% cellulose fibers. The absorbent core can contain at least 80%, at least 90%, at least 95% or at least 99% absorbent material by weight of the absorbent core. The term "superabsorbent polymer" refers herein to an absorbent material that can be a cross-linked polymer and that is typically capable of absorbing at least 10 times its own weight in a 0.9% saline solution when measured using the Centrifuge Retention Capacity (CRC) test (EDANA method WSP 241.2-05E). SAPs can specifically have a CRC value of more than 20 g / g, or more than 24 g / g, or from 20 g / g to 50 g / g, or from 20 g / g to 40 g / g, or from 24 g / g to 30 g / g. SAPs can typically be in particulate form (superabsorbent polymer particles), but other forms of SAP, such as, for example, superabsorbent polymer foams, are not excluded.

[0052] Acquisition-distribution system

[0053] refer to Figure 1 and Figure 2 , the absorbent article 20 of the present disclosure includes an acquisition-distribution system ("ADS") 50. One function of the ADS 50 is to quickly acquire body fluids, such as urine, and distribute them in an efficient manner to the absorbent core 28. The ADS 50 includes a nonwoven as disclosed and discussed in further detail below.

[0054] The ADS 50 may be a single layer. It may include two or more layers that may form an integral structure or may be maintained as discrete layers that may be attached to each other by, for example, thermal bonding, adhesive bonding, or a combination thereof. The integral structure herein is intended to mean that although it may be formed by several sub-layers having different properties and / or compositions from one another, they are mixed in a certain way at the boundary region so that the region where the different sub-layers transition from one to another can be identified, rather than a clear boundary between the sub-layers. Such integral structures are typically constructed in the following manner: each sub-layer is formed one on top of another in a continuous manner (e.g., using air-laid or wet-laid deposition). Typically, no adhesive is used between the sub-layers of a single material. However, in some cases, an adhesive and / or binder may be present, but its content is typically lower than that in a multilayer material formed by a separate layer.

[0055] In the absorbent article according to the present invention, the ADS comprises the nonwoven disclosed herein.

[0056] The ADS may have an air permeability of not less than about 110 m³ / s as measured by an air permeability test. 3 / m 2 / min to about 320m 3 / m 2 / min air permeability and / or a wicking rate of not less than about 120 mm@300 s as measured by the Wicking Rate Test.

[0057] Further details regarding the nonwovens disclosed herein for use as ADS are discussed further below in a dedicated section.

[0058] nonwovens

[0059] The nonwovens disclosed herein can be used in a variety of disposable absorbent articles, but are particularly useful in diapers, feminine hygiene products, and incontinence products such as sanitary napkins and incontinence pads. The nonwovens disclosed herein can be particularly effective as acquisition-distribution systems ("ADS") in absorbent articles.

[0060] See also Figure 3 and Figure 4 , the nonwoven 300 disclosed herein includes open pores 330. Figure 5 and Figure 6 (which is a SEM image), the nonwoven fabric 300 disclosed herein includes absorbent fibers 310 and microfibers 320 .

[0061] The nonwoven fabrics of the present invention may comprise from about 65% to about 97%, from about 70% to about 95%, or from about 80% to about 95% by weight of absorbent fibers, specifically including any value within these ranges and any ranges derived therefrom. The absorbent fibers are used to absorb liquid insults.

[0062] Any suitable absorbent fiber may be utilized. Some conventional absorbent fibers include cellulose-based fibers. Cellulose-based fibers suitable for use in the present invention may be staple fibers having a fiber length of not less than about 30 mm, about 30 mm to about 100 mm, or about 30 mm to about 50 mm, or about 35 mm to about 50 mm, with all values ​​within these ranges and any ranges derived therefrom being specifically recited. The absorbent fiber may be regenerated cellulose fiber. In one embodiment, the absorbent fiber is viscose fiber.

[0063] As previously mentioned, in addition to absorbent fibers, the nonwoven fabrics disclosed herein may also include microfibers. The microfibers used in the present invention may be hydrophobic fibers. In the case where the microfibers are hydrophobic, the fibers themselves absorb little body fluid.

[0064] Ultrafine fibers can be formed using, for example, a meltblown spinning method, or can be made by splitting split-film conjugate fibers. When ultrafine fibers are formed by splitting split-film conjugate fibers, the split-film conjugate fibers make it possible to form ultrafine fibers and to tightly entangle the ultrafine fibers and absorbent fibers by a hydroentanglement process (i.e., a spunlace process) using a high-pressure water flow. After the hydroentanglement process, the split-film conjugate fibers may not be completely split into corresponding structural components. For example, it is acceptable to split only a portion of the structural components. Alternatively, it is also acceptable that the ultrafine fibers are not completely independent fibers, but one or more ultrafine fibers are branched out from a single split-film conjugate fiber. In the case where the splitting of the split-film conjugate fibers into ultrafine fibers stops midway, the fibers that are not completely split into ultrafine fibers are still considered to be ultrafine fibers.

[0065] See also Figure 7A and Figure 7B , the split-film conjugate fibers may have a fiber cross-sectional structure in which at least one component is divided into two or more segments, and at least a portion of each component is exposed to the fiber surface, and the exposed portion is continuously formed in the longitudinal direction of the fiber. The split-film conjugate fibers each have, for example, Figure 7A The cross-sectional configuration shown in FIG. 1 includes a first plurality of segments 322 and a second plurality of segments 324 arranged circumferentially in an alternating manner. When the split-film conjugate fiber having such a configuration is subjected to an impact during a fiber splitting process such as hydroentanglement, the split-film conjugate fiber is split at the interface between the polymer segments 322 and 324 into split microfibers composed of the polymer segments 322 and 324.

[0066] The split-film conjugate fiber may include a combination of two polymers selected from polyethylene terephthalate ("PET"), polyester, polyethylene ("PE"), polypropylene ("PP"), ethylene propylene copolymer, and polyamide ("PA"). The split-film conjugate fiber may include a combination such as PET / PE, PET / PP, PET / PA, PET / ethylene propylene copolymer, PP / PE, or PA / PE.

[0067] The microfibers may have a diameter of no greater than about 2 μm or no greater than about 1.5 μm as measured by the Fiber Diameter Test disclosed herein. If the microfiber fineness is too high, it may not be possible to effectively form a narrow space between the absorbent fibers and the microfibers to restrict the movement of liquid.

[0068] Without wishing to be bound by theory, the distance between the absorbent fibers and the microfibers can affect the wicking rate of the nonwoven and the dry feel of an absorbent article comprising the nonwoven of the present invention. Microfibers do not have strong water absorption properties, and when microfibers are present in close proximity to absorbent fibers and at a short distance from the absorbent fibers, the microfibers can restrict the movement of body fluids away from the absorbent fibers, thereby increasing the bond strength between the absorbent fibers and water. The fiber diameter can affect the distance between the absorbent fibers and the microfibers.

[0069] In order to form ultrafine fibers from split-film conjugated fibers, Figure 7A and Figure 7B The split-film conjugate fiber having the cross-sectional configuration shown in FIG may have a denier of 1.5 to about 2.5, and the number of circumferentially arranged split-film segments in the split-film conjugate fiber may be about 8 to about 20. If the number of circumferentially arranged segments is increased, ultrafine fibers with smaller diameters may be formed.

[0070] When the ultrafine fibers are short fibers, the fiber length of the ultrafine fibers may be selected from the range of, for example, about 5 mm to about 100 mm, or about 20 mm to about 60 mm, or about 30 mm to 60 mm.

[0071] The absorbent fibers and microfibers of the nonwoven disclosed herein are tightly entangled with each other, and the nonwoven has a high wicking rate. Therefore, the nonwoven disclosed herein can be suitable for use as components such as acquisition and / or distribution layers in disposable absorbent articles.

[0072] When liquid forms a continuous stream driven by gravity, the penetration rate follows Darcy's law, and the high permeability of the ADS, as measured by its air permeability, is a factor in achieving high acquisition rates. Downstream of the continuous stream, the liquid's gravity cannot generate sufficient pressure to drive the liquid in the z-direction to the ADS, and the capillary gradient plays a primary role in draining the liquid from the topsheet downward to the ADS. Consequently, the high capillary force of the ADS can result in a small amount of liquid being retained in the topsheet, creating a dry sensory sensation. Capillary force is characterized by the wicking rate.

[0073] As previously mentioned, in addition to the absorbent fibers and microfibers, the nonwoven fabric of the present invention also includes a plurality of apertures having a hydraulic diameter in the range of about 600 μm to about 4500 μm. If the hydraulic diameter of the aperture is too small, the liquid penetration rate will be negatively impacted. If the hydraulic diameter of the aperture is too high, when the nonwoven fabric is used as an ADS in an absorbent article, the connection between the nonwoven fabric and other components (such as the top sheet of the absorbent article) will be reduced and result in poor liquid drainage.

[0074] As measured by the fiber mixing degree test disclosed herein, the nonwoven of the present invention can have a fiber mixing degree of not less than about 0.040, or less than 0.043, or less than 0.045. Without being bound by theory, the distance between the absorbent fibers and the microfibers can affect the wicking rate of the nonwoven. Microfibers do not have strong water absorption properties, and when microfibers are closely adjacent to the absorbent fibers and are at a shorter distance from the absorbent fibers, the microfibers can limit body fluids from moving away from the absorbent fibers, thereby improving the bond strength between the absorbent fibers and the water.

[0075] The nonwoven can have a total open area of ​​about 5% to about 21%. If the total open area % is too low, the liquid penetration rate is negatively affected. If the total open area % is too high, when the nonwoven is used as an ADS in an absorbent article, the connection between the nonwoven and other components (such as the top sheet of the absorbent article) will be reduced and lead to poor liquid drainage.

[0076] The nonwovens disclosed herein may have a basis weight of not less than about 30 gsm, or not less than about 35 gsm, or not less than about 40 gsm. If the basis weight of the nonwoven is too low, the capillary gradient may not be effectively generated due to the low amount of absorbent fibers.

[0077] The nonwovens disclosed herein may have an air permeability of not less than 110 m / s as measured by the Air Permeability Test disclosed herein. 3 / m 2 / min or not less than about 120m 3 / m 2The air permeability can be not less than 1000 cfm / min. If the air permeability is too low, it has a negative impact on liquid penetration. The upper limit of the air permeability can not be critical as higher air permeability is advantageous in terms of acquisition speed and can be determined considering the processability of the absorbent article production. For example, if the permeability of the nonwoven is too high, it is not efficient to process in the vacuum conveying system in the absorbent article production. This can also lead to process failure as the adhesive easily bleeds from the nonwoven if the permeability of the nonwoven is too high.

[0078] The nonwoven disclosed herein can have a wicking rate of not less than 120 mm @ 300 s as measured by the Liquid Test in the Top Sheet disclosed herein. If the wicking rate is too low, the nonwoven can not have sufficient suction to pull liquid down from the topsheet and have an adverse effect on the dryness of the topsheet when the nonwoven is used as an ADS in an absorbent article.

[0079] Method of manufacturing a nonwoven

[0080] The nonwoven can be formed by any suitable method known in the nonwoven industry. In one example, each of the cellulose-based fiber and the split conjugate fiber is fed separately into a fiber breaking unit. The fiber breaking machine loosens the gathered fiber clusters into relatively loose fibers and places them on the same conveyor belt according to a predetermined weight ratio. Then, the two fibers are transported into a fiber mixing container where the cellulose-based fiber and the split conjugate fiber are mixed. The fiber mixture is laid on a forming belt by a suitable method such as a carding method, an air-laid method, and a wet-laid method to form a fiber web. The fiber web can be processed to split the split conjugate fiber and entangle all the component fibers by hydroentangling with a water jet (also known as spunlace) to obtain a nonwoven.

[0081] In another example, the split conjugate fiber is first charged into a water container. The fiber is treated with a hot alkali solution for a certain time to split the split conjugate fiber into ultrafine fibers. After that, the alkali solution is drained from the container and an acid solution is added to the container to neutralize the free alkali. After that, the acid solution is drained and pure water is added to rinse the fiber. Then, the viscose fiber is added to the container in the presence of water to mix with the ultrafine fiber according to a predetermined weight ratio. The fiber mixture is pulled out into a fiber web by a conveyor belt and then hydroentangled by a spunlace unit to obtain a nonwoven. In this method, the fiber mixing speed, mixing time, and agitator design can be important to control the degree of mixing between the absorbent fiber and the ultrafine fiber.

[0082] After the hydroentangling, the nonwoven is optionally subjected to a drying step to further dry the nonwoven.

[0083] Open pores can be formed using a spunlace process. The size of the pores is determined by the screen design and the water jet pressure. The purpose of creating open pores in a spunlace process is to balance pore definition with nonwoven strength. To achieve the desired level of nonwoven strength, the fibers need to be firmly entangled, but these firmly entangled fibers are difficult to be pushed by the water on a large screen to form large pores.

[0084] The apertures can be formed after the spunlace process by a post-aperture process known in the nonwoven industry. For example, the apertures can be formed by Figure 8 The punching process schematically shown in FIG is formed. First, the precursor nonwoven web 292 is fed into the punching unit 296 together with the consumable material 294 in a face-to-face manner. The precursor nonwoven web 292 can be unwound from roller A. The consumable material 294 can be unwound from roller B. The consumable material 294 can have a greater stiffness than the precursor nonwoven web 292 and can be used to increase the stiffness of the precursor nonwoven web 292 during the aperture process. The consumable material 294 can be, for example, a cardboard having a stiffness greater than that of the precursor nonwoven web 292. Compared to the aperture process in the related art, this increase in stiffness can allow the formation of cleaner, more regular holes with fewer or no hole perimeter tails. In another example, the consumable material 294 can be replaced by a collection layer, wherein the precursor nonwoven web 292 and the collection layer can be unwound from their respective rollers and bonded together to form a laminate before entering the punching unit 296. For example, an actuator 298 (such as a pneumatic actuator) moves a punching unit 296 comprising a plurality of punching members 297 toward the precursor web to create holes in the nonwoven web 292 and the consumable material 294. The punched sheet can then be at least partially removed or completely removed by directing a fluid (e.g., air) onto the nonwoven web, or by placing the nonwoven web under vacuum (block C) after the holes have been created in the nonwoven web. After the holes have been created, the nonwoven web can be directly wound or transferred to a manufacturing operation for a consumer product (such as an absorbent article).

[0085] Measurement

[0086] 1. SEM image test

[0087] (1) Sample preparation

[0088] When the nonwoven is available in raw material form, a sample of 10 mm x 20 mm is cut from the raw material. When the nonwoven is a component of a finished product, the nonwoven is removed from the finished product using a razor blade, separating the nonwoven from other components of the finished product, and cut to provide a nonwoven sample of 10 mm x 20 mm with no folds or wrinkles. If necessary, a cryogenic spray such as Cyto-Freeze (Control Company, Houston TX) can be used to remove the nonwoven fabric sample from other components of the finished product.

[0089] To measure the top view of the sample, the sample is adhered horizontally to a copper plate (40 mm diameter, 30 mm thickness) by double-sided conductive tape.

[0090] To measure the cross-section of the sample, the sample is first soaked in liquid nitrogen for 180 seconds, and then cut perpendicularly to the sample plane direction with a steel knife. After cutting, the sample is adhered vertically to a copper plate with the cut face facing up by double-sided conductive tape.

[0091] The plate is then placed in the sample chamber of a coating instrument (such as Hitachi E-1045) for platinum sputter coating. During coating, the gas pressure in the sample chamber is controlled to be below 100 Pa, and the charge current is 300 mA. After 120 seconds of coating, the copper plate is removed.

[0092] (2) Image generation

[0093] The coated sample adhered to the copper plate is placed in the chamber of a SEM instrument (Hitachi TM3000) for measurement. For top view images, SEM images are obtained at a resolution sufficient to clearly illustrate the absorbing fibers and microfibers present in the sample. For cross-section view images, SEM images are obtained at a resolution sufficient to clearly illustrate the cross-sections of the fibers present in the sample.

[0094] 2. Fiber diameter test

[0095] According to the above SEM image test, SEM images of the cross-section view of the nonwoven sample are generated.

[0096] Fiber diameter is analyzed by image analysis software such as ImageJ software (version 1.52p or later, National Institutes of Health, USA) or equivalent. The measurement photo is opened in ImageJ. The image type is converted to 8-bit. The gray scale of the 8-bit image is 0 to 255. The fibers have high gray values, while the background has low gray levels.

[0097] Select a single fiber section with a clean black background. Draw a line perpendicular to the fiber section and through the fiber, with a length of about 2 times the fiber width. Then, record the grayscale of each pixel on this line. The boundary between the fiber and the background is defined as the grayscale value of "Gray min +0.2×(Gray max -Gray min Gray max and Gray min are the maximum and minimum grayscale values ​​on the line respectively.

[0098] The fiber width, considered to be the fiber diameter, is then determined as the distance between the two boundary points on the line.If the fiber is not perfectly circular (eg, elliptical), the smallest dimension of the fiber, such as the minor axis, is considered to be the fiber diameter.

[0099] 3. Hygroscopicity test

[0100] (1) Instrument

[0101] Balance: precision 0.001g

[0102] Oven: Heating temperature control with an accuracy of 1°C.

[0103] Fan: circulates air between the interior and exterior for drying purposes;

[0104] (2) Procedure :

[0105] Take 50g-55g of fiber and record the weight as G0.

[0106] The fibers were placed loosely on a plate at 23°C (+ / - 2°C) and 50% RH (45%-55% RH) for 24 hours to reach equilibrium, and the weight was then recorded as G1.

[0107] The oven was turned on and the temperature was set to 108° C. When the temperature reached 108° C. (+ / - 2° C.), the fiber was placed in the oven and allowed to stand for 40 minutes.

[0108] After 40 minutes, the fibers were removed from the oven for rapid weighing within 60 seconds and then placed back into the oven.

[0109] Every 10 minutes, the fibers were removed from the oven and weighed, and they were placed back into the oven until the difference between two consecutive measurements was less than 0.01 g. The final weight was recorded as G2.

[0110] The moisture absorption rate R is calculated as follows:

[0111] R = (G1 - G2) / G2 x 100%.

[0112] 4. Aperture size test

[0113] (1) Sample preparation

[0114] When the nonwoven is available in raw material form, a sample measuring 50 mm x 50 mm is cut from the raw material. When the nonwoven is a component of a finished product, a razor blade is used to remove the nonwoven from the finished product and cut the nonwoven from other components of the finished product to provide a nonwoven sample measuring 10 mm x 20 mm. If necessary, a cryogenic sprayer (such as Cyto-Freeze, Control Company, Houston TX) can be used to remove the nonwoven from other components of the finished product.

[0115] (2) Image generation

[0116] Microscopic images of the nonwoven are obtained by using an optical microscope such as a VR-3200 (KEYENCE, Japan) or equivalent. Appropriate magnification and working distance are selected so that a single opening is adequately magnified for measurement. The image should have sufficient resolution, at least 100 pixels across the opening diameter.

[0117] (3) Image analysis

[0118] The hydraulic diameter of the perforation is analyzed by image analysis software such as ImageJ software (version 1.52p or above, National Institutes of Health, USA) or equivalent. The measurement photos are opened in ImageJ. The image type is converted to 8 bits. The image needs to be calibrated with a ruler image to give the image resolution.

[0119] The 8-bit grayscale image is then converted into a binary image (where “black” foreground pixels correspond to hole regions) using the “minimum” thresholding method: if the grayscale (GL) value histogram (ranging from 0 to 255, with each grayscale value i having a tendency P i The bin has exactly two local maxima, and the threshold t of the gray level value is defined as P under this value. t-1 >P t And P t ≤P t+1 If the histogram has more than two local maxima, the histogram is iteratively smoothed using a windowed arithmetic mean of size 3, and this smoothing is performed iteratively until there are exactly two local maxima. The grayscale value threshold t is defined as the value P at which t-1 >P t And P t ≤P t+1The procedure identifies the gray level (GL) value of the smallest population located between the dark pixel peak of the opening and the lighter pixel peak of the sample material. If the histogram contains zero or one local maximum, the method cannot proceed and the output parameters are not defined.

[0120] A filtered image was created by removing small openings from the binary image using an outlier removal median filter that replaced a pixel with the median of the surrounding area with a radius of 5 pixels if the pixel was darker than the surrounding pixels. A second filtered image was created based on the first filtered image by removing stray fibers from the binary image using an outlier removal median filter that replaced a pixel with the median of the surrounding area with a radius of 5 pixels if the pixel was brighter than the surrounding pixels. Measurements were set to include analysis of both the area (A) and perimeter (L) of the opening. The opening was traced through the outer edge of the opening and sizes below 2000 μm were excluded. 2 After selecting the openings, the area and perimeter of the selected openings (“quality openings”) are obtained.

[0121] The hydraulic diameter is calculated by 4×A / L.

[0122] 5. Open area test

[0123] The images generated using a flatbed scanner were subjected to aperture opening percentage measurements that can be scanned in reflective mode at a resolution of 6400 dpi and 8-bit grayscale (a suitable scanner is an Epson Perfection V750 Pro, Epson, USA). Analysis was performed using ImageJ software (version 1.46, National Institute of Health, USA) and calibrated using a straightedge certified by NIST. Steel frames (100 square millimeters, 1.5 mm thick, with an opening of 60 square millimeters) were used to mount the sample and black glass tiles (P / N 11-0050-30, available from HunterLab, Reston, VA) were used as the background for the scanned images.

[0124] Obtain steel frame and around inner opening double-sided adhesive tape is placed on the bottom surface.In order to obtain sample, nonwoven is laid flat on laboratory workbench.Use double-sided conductive tape, steel frame is adhered on the nonwoven.Also can measure the test sample obtained from the nonwoven removed from absorbent article.If necessary, can use cryogenic sprayer (such as Cyto-Freeze, Control Company, Houston TX) or other suitable solvents that do not permanently change the property of nonwoven sample composition to remove nonwoven from other parts of absorbent article.

[0125] When cutting a layer of material from an absorbent article, be careful not to cause any contamination or deformation to the layer during the process. If the layer of material has been cut from an absorbent article, the test location is the intersection of the midpoints of the longitudinal and lateral axes of the absorbent article.

[0126] Place a ruler on the scanner bed, close the lid and acquire a 50mm x 50mm calibration image of the ruler in reflective mode at a resolution of 6400 dpi and 8-bit grayscale. Save the image as an uncompressed TIFF file. Lift the lid and remove the ruler. After obtaining the calibration image, scan all samples under the same conditions and measure based on the same calibration file. Next, place the framed sample in the center of the scanner bed. Place a black glass tile on top of the frame, covering the sample, close the lid and acquire a scanned image. Scan the remaining four parallel samples in a similar manner.

[0127] Open the calibration file in ImageJ and use the ruler of imaging to perform linear calibration, set the scale to Global so that the calibration will be applied to subsequent samples. Open the sample image in ImageJ. Observe the histogram and identify the grayscale value of the smallest group between the dark pixel peak located in the pore and the brighter pixel peak of the nonwoven. Set the threshold of the image to the minimum grayscale value to generate a binary image. In the processed image, the pore appears black and the nonwoven appears white.

[0128] Select the Analyze Particles function. Set the minimum open area exclusion limit to 0.02 mm2 and exclude edge openings for analysis purposes. Set the software to calculate the effective open area. Record the average effective open area to the nearest 0.01 mm 2 Again, select the Analyze Particles function, but this time set the analysis to include edge pores when calculating the effective open area. Sum the effective open areas (including both full and partial open areas) and divide by the total area included in the image (2500 mm2). Record this as the percentage of open area to the nearest 0.1%.

[0129] 6. Fiber mixing degree test

[0130] The degree of fiber mixing was determined using scanning electron microscopy (SEM) image analysis of nonwoven cross sections. The analysis procedure is described below.

[0131] Input image: A SEM image of a cross-sectional view of a nonwoven sample generated according to the SEM image test described above.

[0132] Image Recognition: Figure 9A is a SEM image of a cross-sectional view of a nonwoven (magnification 500 times). Figures 9A to 9C , absorbent fibers and microfibers inFigure 9A They are manually identified and labeled as two binary images respectively. Figure 9B and Figure 9C They are the binary images of the absorbing fiber and the binary images of the ultrafine fiber with the same field size, respectively.

[0133] Calculation of fiber density for mesh and absorbent fiber / microfiber ratio matrix:

[0134] a. Calculate the total density of absorbing fibers by dividing the total number of absorbing fiber pixels by the total number of pixels in the image.

[0135] b. Divide both the coarse fiber image and the fine fiber image into 32 μm wide square grids. For each grid, calculate the fiber density of coarse fibers and fine fibers by dividing the number of fiber pixels in each grid by the total number of pixels ( and ).

[0136] c.through The ratio of fine fibers to absorbent fibers (R i ). However, if Less than total absorbent fiber density , the ratio is set to zero.

[0137] d. By all R i The averages were taken to calculate the fiber mixing ratio "R".

[0138] For each nonwoven sample, 10 SEM images of different nonwoven cross-section portions were tested.The reported value is the average of the 10 recorded measurements for each nonwoven sample.

[0139] 7. Air permeability test

[0140] The air permeability of nonwovens was measured using European Disposables and Nonwovens Association (EDANA) 140.2-99 with the following modifications.

[0141] (1) Analysis area: 38.3 cm 2 ,

[0142] (2) Pressure drop: 125Pa, and

[0143] (3) Recording unit: m 3 / m 2 / min

[0144] 8. Wicking rate test

[0145] The wicking rate measurements provided herein were obtained using European Disposables and Nonwovens Association (EDANA) test method 70.1.

[0146] 9. Fluid acquisition test

[0147] See also Figures 10A to 10C , place the sample absorbent article 20 on a workbench plate 610 measuring 250 mm x 400 mm, which has a hollow portion 612 in the middle of the plate, with the top sheet 24 facing upward. Attach the front and rear edges of the absorbent article 20 to the plate 610 using hook material, adhesive tape, or the like. Draw the longitudinal centerline 80. The loading center LC of the loading position is along the longitudinal centerline 80 and is 12 cm from the front edge 10 of the absorbent article 20.

[0148] The loading tool 620 is placed on top of the loading position so that the loading center LC is located in the middle of the loading tube 622. The weights 624 (500 g each) on the loading tool 620 generate a pressure of approximately 0.3 psi. The equilibrium time before the first loading feed is 5 minutes. A first surge of 75 ml of 0.9% saline solution is loaded through the loading tube 622. The equilibrium time between consecutive loads is 5 minutes. A second surge of 75 ml of 0.9% saline solution and a third surge of 75 ml of 0.9% saline solution are loaded in the same manner as the first surge. During each surge, a timer is started when liquid is loaded into the loading tool. The timer is stopped when the liquid level in the tube 622 is less than 0.5 mm. This time is recorded as the acquisition time for one surge, i.e., Ti (i=1, 2, or 3). The total acquisition time is obtained according to the following equation (1).

[0149] Total acquisition time T 总 =T1+T2+T3 (1)

[0150] 10. Liquid test in top sheet

[0151] The amount of liquid in the top sheet is measured using the sample in the above-mentioned fluid collection time test. Before the first surge, carefully remove the top sheet from the lower layer of the sample absorbent article. If necessary, a cryogenic sprayer (such as Cyto-Freeze, Control Company, Houston TX) or other suitable solvent can be used to remove the top sheet from the lower layer. The dry weight of the top sheet is weighed and recorded as W0. Then, the removed top sheet is reattached to the lower layer of the sample absorbent article using 1gsm glue. After the third surge tested according to the fluid collection time, the loading tool is kept on the top sheet for 5 minutes before removal. Then, the top sheet is carefully removed from the sample absorbent article for weighing. The weight of the top sheet is recorded as W1. The liquid in the top sheet is calculated according to the following formula (2).

[0152] Liquid in top sheet = W1-W0 (2)

[0153] Example

[0154] Example 1: Nonwoven

[0155] Nonwoven samples were prepared and analyzed for various properties according to the methods described in the "Measurement" section above. The results are summarized in Table 1.

[0156] Sample 1 A 58 gsm open-aperture spunlace material was prepared using a 100-mesh carding-spunlace process from 95 wt% 1.7 dtex viscose fibers (fiber length: 40 mm, moisture absorption: approximately 11%) and 5 wt% 2-denier split PET / PA conjugate fibers (fiber length: 38 mm, 8 segments each of PET and PA, PET / PA = 60 / 40 wt%). The apertures had a hydraulic diameter of 180 μm.

[0157] Samples 2-14 Apertured spunlaced materials were prepared using a carding-spunlaced process and post-aperture process from the same viscose fibers and split PET / PA fibers as used in Sample 1 at various ratios and aperture sizes as shown in Table 1. In Samples 2-8, the apertures were formed by the spunlaced process using a suitable mesh. In Samples 9-11, 13, and 14, the apertures were formed using the punching process disclosed herein. Figure 5 and Figure 6 is a plan view SEM image of Sample 6. Figures 11 to 13 SEM images of cross-sectional views of samples 5, 6, and 10, respectively (image resolution: approximately 0.04 μm / pixel).

[0158] Sample 15 A 60 gsm open aperture spunlace material comprising 90 wt% viscose fibers (fiber length: fiber fineness:) and 10 wt% ultrafine PET fibers and PA fibers was prepared using a card-spunlace process, wherein the apertures had a hydraulic diameter of 670 μm. Figure 14 The SEM image is a cross-sectional view of Sample 15.

[0159] Sample 16 : Using a 100 mesh carding-spunlace process, a 60 gsm open-aperture spunlace material with an opening size of 180 μm was prepared from 90 wt% cotton fibers (fiber length: 22 mm-28 mm, moisture absorption rate: about 6%) and 10 wt% of the same split-film PET / PA composite fibers used in Sample 1.

[0160] Sample 17A 60 gsm open aperture spunlace material with an aperture size of 920 μm was prepared using a card-spunlace process from the same cotton fiber and split PET / PA composite fiber (90:10 wt%) as used in Sample 16. Apertures with a hydraulic diameter of 920 μm were formed using the punching method disclosed herein.

[0161] Sample 18 A 55 gsm open aperture spunlace material comprising 100% 1.7 dtex viscose fibers (fiber length: 40 mm, moisture absorption: 10%-12%) with a hydraulic diameter of 180 μm was prepared using a 100 mesh screen card-spunlace process.

[0162] Samples 19-22 Using a 100-mesh screen card-spunlace method, apertured spunlace materials were prepared from 1.7 dtex viscose fibers (fiber length: 40 mm, moisture absorption: 10%-12%) and PET fibers at various ratios and aperture sizes as shown in Table 1. The apertures had a hydraulic diameter of 180 μm.

[0163] Sample 23 : 40 gsm airlaid carded nonwoven (Z87G from Xiamen Yanjan New Material Co. Ltd, China) obtained from 2 denier PE / PET bicomponent fibers and 4 denier PE / PET bicomponent fibers (60:40 wt%).

[0164] Sample 24 : 43gsm nonwoven (AQL2+, obtained from TWE Nonwoven (Hangzhou) Co. Ltd, China)

[0165] Sample 25 : 80 gsm laminate nonwoven (B643H080N00B, available from Fitesa, China) with a 20 gsm hydrophilic airlaid nonwoven top layer and a 60 gsm airlaid pulp bottom layer.

[0166] Sample 26 A nonwoven laminate was prepared with a top layer of 60 gsm viscose and a bottom layer of 20 gsm microfiber. The viscose layer was made from the same viscose fiber used in Sample 1 using a 100 mesh carding-spunlace process. The microfiber layer was made from the same split-film conjugate fiber used in Sample 1 using a carding-spunlace process. The viscose layer and the microfiber layer were laminated using 2 gsm adhesive. Open holes with a hydraulic diameter of 670 μm were then formed in the laminate using a punching process. Figure 15 is a SEM image of a cross-sectional view of Sample 26 (image resolution: about 0.04 μm / pixel).

[0167] Sample 27 A nonwoven laminate was prepared having a top layer of 20 gsm microfiber and a bottom layer of 60 gsm viscose. The microfiber layer was made from the same split-film conjugate fiber used in Sample 1 using a carding-spunlace process. The viscose layer was made from the same viscose fiber used in Sample 1 using a 100 mesh screen carding-spunlace process. The viscose layer and the microfiber layer were laminated using 2 gsm adhesive. Open holes with a hydraulic diameter of 670 μm were then formed in the laminate using a punching process.

[0168] Example 2: Nonwoven properties

[0169] The pore diameter, open area, air permeability, and wicking rate of the nonwovens prepared in Example 1 were measured according to the pore size test, open area test, permeability test, and wicking rate test disclosed herein, respectively, and are shown in Table 1. The fiber mixing degree of nonwovens 6, 10, 15, and 26 prepared in Example 1 was measured according to the fiber mixing degree test disclosed herein and is shown in Table 1.

[0170] Table 1

[0171]

[0172]

[0173] microfiber * :From split film PET / PA fiber

[0174] Opening diameter * : Hydraulic diameter of the opening

[0175] Example 3: Absorbent article

[0176] Diaper sample 1-27 uses Pampers Hajimeteno Hadaeno Ichiban, size L (Procter and Gamble Japan KK Japan) and in embodiment 1 as the nonwoven fabric manufacturing of AQS preparation, this nonwoven fabric is arranged between top flat and absorbent cores.First, by using cold spray agent, carefully remove top flat and the AQS layer that is arranged between top flat and absorbent cores from Pampers Hajimeteno Hadaeno Ichiban diaper.Then, use 1gsm spiral adhesive to be made of 22gsm hydrophilic breathable nonwoven fabric (deriving from XiamenYanjan New Material Co.Ltd, China's Z63) of 1.2 denier hydrophilic PE / PET bicomponent fibers, be laminated on remaining diaper as every kind of nonwoven fabric as ADS material prepared in top flat and embodiment 1 loosely, make top flat and ADS be connected to each other and be connected on remaining diaper, and can easily separate after test.

[0177] Example 4: Properties of absorbent article

[0178] The diaper samples prepared in Example 3 were analyzed for Total Acquisition Time and Liquid in Topsheet according to the Fluid Acquisition Test and Liquid in Topsheet Test described in the "Measurements" section above. The results are summarized in Table 2.

[0179] Table 2

[0180]

[0181]

[0182] The dimensions and values ​​disclosed herein are not to be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

[0183] Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any application disclosed or claimed herein or that it alone, or along with any other document or together with any relevant art, teaches, suggests or discloses any such application. Further, the citation of any document is not an admission that it is prior art with respect to any application disclosed or claimed herein or that it alone, or along with any other document or together with any relevant art, teaches, suggests or discloses such application. In addition, with respect to any document that has a priority date or filing date prior to the priority date or filing date of this application, the priority date or filing date of this application is used, not the priority date or filing date of the earlier document. Finally, documents that are incorporated by reference herein are not admitted to be prior art with respect to the application, unless expressly so stated.

[0184] While particular embodiments of the present application have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the application. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this application.

Claims

1. An absorbent article comprising: Liquid-permeable topsheet, Liquid-impermeable backsheet, an absorbent core disposed between the top sheet and the back sheet, and an intermediate layer disposed between the top sheet and the absorbent core, the intermediate layer comprising a nonwoven fabric, The nonwoven fabric comprises: i) multiple openings, ii) absorbent fibers, and iii) 3% to 35% by weight of the nonwoven of ultrafine fibers, wherein the ultrafine fibers have a diameter of no greater than 2 μm, and wherein the opening has a hydraulic diameter in the range of 600 µm to 4500 µm as measured according to the Opening Size Test, wherein the hydraulic diameter is calculated by 4×A / L, where A is the opening area of ​​the opening and L is the perimeter of the opening.

2. The absorbent article of claim 1, wherein the absorbent fibers are cellulose-based fibers.

3. The absorbent article according to claim 1 or 2, wherein the nonwoven is a hydroentangled nonwoven.

4. The absorbent article according to claim 1 or 2, wherein the topsheet comprises cellulose-based fibers.

5. The absorbent article of claim 1 or 2, wherein the nonwoven has a basis weight of not less than 45 gsm.

6. The absorbent article of claim 1 , wherein the nonwoven has an Air Permeability of not less than 110 m / s as measured by the Air Permeability Test disclosed herein. 3 / m 2 / min air permeability.

7. The absorbent article of claim 1 or 6, wherein the nonwoven has a Wicking Rate of not less than 120 mm@300 s as measured by the Wicking Rate Test disclosed herein.

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