Wearable article including an elastic laminate

Abstract

The present invention discloses a wearable article including an elastic laminate having excellent sweat management characteristics. The elastic laminate includes a first fibrous web and a second fibrous web. The second fibrous web is formed by a first fibrous layer and a second fibrous layer integrally bonded to each other. The second fibrous layer may be more hydrophilic than the first fibrous layer; and / or the second fibrous layer may have a higher average surface area per volume than the first fibrous layer.

Description

Technical Field

[0001] The present invention relates to a wearable article that includes an elastic laminate suitable for a wearable article, and the wearable article exhibits improved sweat management characteristics. Background Art

[0002] Base materials such as nonwoven fabrics and their laminates are commonly used in wearable articles such as absorbent articles. For example, absorbent articles typically use nonwoven base materials on both the skin-facing side and the clothing-facing side of the article to control the movement of liquids and provide a comfortable, conforming fit when the article is worn by a wearer. In terms of comfort, it may be desirable to have a cloth-like base that can effectively absorb sweat and excess moisture from the skin and release them to the outside of the article. For absorbent articles, this is particularly desirable for caregivers of infants, but is not limited thereto, where skin health is closely related to the absence of prickly heat and diaper rash, but is also closely related to absorbent articles (such as pants) for incontinent adults, who are typically older and may also have fragile skin. Prickly heat in the waist area may be associated with the humidity or moisture in the waist area within the absorbent article. Caregivers typically check for humidity or moisture by touching the waist area within the absorbent article worn by an infant.

[0003] Elastic laminates having sweat management characteristics have been proposed, such as those described in Japanese Patent Application Publication Nos. 2017-12319A and 2017-113186A. There is a need to provide an elastic laminate having further improved sweat management characteristics while being manufactured economically.

[0004] An elastic laminate for a belt of, for example, an absorbent pant is typically made of two nonwoven fiber webs that are joined to each other in a face-to-face relationship, with elastic strands sandwiched therebetween. In such a laminate, the first nonwoven fiber web (inner nonwoven fiber web) faces the skin of the wearer and directly contacts the skin over a relatively large area of its surface. The second nonwoven fiber web (outer nonwoven fiber web) faces outward, away from the wearer, and thus it typically contacts the wearer's clothing. Typically, the outer nonwoven fiber web includes an extension portion that is folded over the inner nonwoven fiber web at the edge of the elastic laminate that forms the waist edge of the absorbent pant. Thus, a more underwear-like finished pant appearance is provided. Thus, adjacent to the waist edge, the elastic laminate may include three nonwoven fiber webs, namely, the inner nonwoven fiber web sandwiched between the outer nonwoven fiber web and the extended folded portion of the outer nonwoven fiber web.

[0005] Both the first nonwoven fiber web and the second nonwoven fiber web are typically hydrophobic, which has been found to result in relatively unsatisfactory performance in terms of sweat handling, i.e., transporting sweat from the skin of the wearer through the laminate to the outside.

[0006] To address this shortcoming, it has been proposed to use a hydrophobic inner nonwoven web and a hydrophilic outer nonwoven web. However, this technical approach may have certain limitations, as sweat may not be sufficiently wicked in the plane of the belt itself, and as liquid may accumulate in the outer layer, providing a damp, moist feeling when contacting the outer nonwoven web and potentially wetting the fabric worn over the absorbent pants. Additionally, in an elastic laminate of a belt having an extended folded portion of an outer nonwoven web, at least a portion of the folded portion will typically be in direct contact with the skin of the wearer. In such configurations, the transport of sweat from the skin of the wearer tends to be reduced by the hydrophobic inner nonwoven web that is sandwiched between the hydrophilic folded portion of the outer nonwoven web and the hydrophilic outer nonwoven web.

[0007] There remains a need for an elastic laminate having an improved ability to wick liquid away from the skin of the wearer in an effective manner. Summary of the Invention

[0008] The present invention relates to a wearable article including an elastic laminate. The elastic laminate includes a first web and a second web in a face-to-face relationship. Each of the first web and the second web constitutes the entire surface area of the elastic laminate.

[0009] The first web is a nonwoven web.

[0010] The second web is formed by a first fiber layer and a second fiber layer, where the second fiber layer is more hydrophilic than the first fiber layer; and / or where the second fiber layer has a higher average surface area per volume than the first fiber layer.

[0011] The average surface area per volume of the second fiber layer may be at least 20 [1 / mm], more preferably at least 30 [1 / mm], more preferably at least 50 [1 / mm], more preferably at least 60 [1 / mm], and even more preferably at least 100 [1 / mm] higher than the average surface area per volume of the first fiber layer.

[0012] The first fiber layer and the second fiber layer are integrally bonded to each other. At least some of the fibers in the second fiber layer interpenetrate the fibers of the first fiber layer. The first fiber layer forms the first surface of the second web, and the second fiber layer forms the second surface of the second web. The second surface faces the first web, and the first surface faces away from the first web.

[0013] The first fiber layer and the second fiber layer may each have a contact angle θ, and the first web may have a contact angle θ. The cosine of the contact angle θ multiplied by the average surface area per volume of the second fiber layer (cosθ × average surface area / volume) may be higher than the cosine of the contact angle θ multiplied by the average surface area per volume of the first web.

[0014] (cosθ × average surface area / volume) of the second fiber layer may be at least 20 [1 / mm], more preferably at least 30 [1 / mm], even more preferably at least 50 [1 / mm], still more preferably at least 60 [1 / mm], and even more preferably at least 100 [1 / mm] higher than (cosθ × average surface area / volume) of the first fiber web.

[0015] (cosθ × average surface area / volume) of the second fiber layer may be not more than 500 [1 / mm], or not more than 400 [1 / mm] higher than (cosθ × average surface area / volume) of the first fiber web.

[0016] Cosine of the contact angle θ multiplied by the average surface area per volume of the second fiber layer may be higher than cosine of the contact angle θ multiplied by the average surface area per volume of the first fiber layer.

[0017] (cosθ × average surface area / volume) of the second fiber layer may be at least 20 [1 / mm], more preferably at least 30 [1 / mm], even more preferably at least 50 [1 / mm], still more preferably at least 60 [1 / mm], and even more preferably at least 100 [1 / mm] higher than (cosθ × average surface area / volume) of the first fiber layer.

[0018] (cosθ × average surface area / volume) of the second fiber layer may be not more than 500 [1 / mm], or not more than 400 [1 / mm] higher than (cosθ × average surface area / volume) of the first fiber layer.

[0019] The wearable article may have a longitudinal direction and a transverse direction. In the elastic laminate, elastic strands may be disposed between the first fiber web and the second fiber web. The elastic strands may extend in the transverse direction of the wearable article and may be spaced apart from each other in the longitudinal direction of the wearable article.

[0020] The elastic strands may be directly attached to the first fiber web and / or attached to the second fiber web by an adhesive. The attachment may be continuous along the entire length of the elastic strands, intermittent along the entire length of the elastic strands, or the elastic strands may be attached to the first fiber web and / or the second fiber web only at or near the ends of the first fiber web and / or the second fiber web.

[0021] Both the first fiber web and the second fiber web may be non-elastic.

[0022] The elastic laminate may form a component of the wearable article, and the component may be selected from the group consisting of: an elastic band, a waistband, a side panel, a continuous infrastructure, a leg cuff, and an outer covering.

[0023] In a preferred embodiment, the elastic laminate can be formed of or form an elastic band that is formed by a front band and a rear band. Alternatively, the elastic laminate can form the entire outer surface of a wearable article.

[0024] The first fibrous web of the elastic laminate can form the inner fibrous web of the elastic band, and the second fibrous web can form the outer fibrous web of the elastic band. Alternatively, the first fibrous web of the elastic laminate can form the outer fibrous web of the elastic band, and the second fibrous web can form the inner fibrous web of the elastic band.

[0025] The front band can form the front waist edge of the wearable article, and the rear band can form the rear waist edge of the wearable article.

[0026] The outer fibrous web of the elastic band can include an extension portion that extends beyond the front waist edge and the rear waist edge, and the extension portion is folded over the inner fibrous web such that the fold forms the front waist edge and the rear waist edge, and at least a portion of the elastic band includes the inner fibrous web sandwiched between the outer fibrous web and the extension portion of the outer fibrous web.

[0027] If the elastic laminate forms the front and rear bands of the wearable article, the front and rear bands together form an annular elastic band, and the wearable article can further include a central infrastructure. The center of the front band can be joined to the front waist panel of the central infrastructure, and the center of the rear band can be joined to the rear waist panel of the central infrastructure. The remainder of the central infrastructure can form the crotch region. The front and rear bands can each have a left side panel and a right side panel, wherein the central infrastructure does not overlap, and the lateral edges of the front and rear bands can be joined by seams to form a waist opening (composed of the front waist edge and the rear waist edge) and two leg openings. The front and rear bands can be discontinuous with each other in the longitudinal direction in the crotch region.

[0028] The central infrastructure can include an outer cover layer on the clothing-facing surface and a backsheet attached to the outer cover layer on the wearer-facing surface. The longitudinal length of the outer cover layer can be longer than the longitudinal length of the crotch region and shorter than the longitudinal length of the backsheet.

[0029] If the elastic laminate forms the elastic band of the wearable article, the first fibrous web or the second fibrous web of the elastic laminate can form the outer fibrous web of the elastic band. According to the test method described herein, the outer fibrous web can have a plurality of openings, such as open holes, with an opening ratio of about 5% to about 50%, preferably about 5% to about 30%. According to the test method herein, the outer fibrous web can have an effective opening area of 0.1 mm 2 to 25 mm 2 , preferably 0.1 mm 2 to 10 mm 2 of the effective opening area.

[0030] The respective other one of the first fibrous web and the second fibrous web may form the internal fibrous web of the elastic band. According to the test method of the present invention, the internal fibrous web may have a plurality of openings, such as open holes, with an opening ratio of 5% to 30%, preferably 5% to 15%, and the effective opening area of the internal fibrous web is 0.1 mm 2 to 25 mm 2 preferably 0.1 mm 2 to 10 mm 2 .

[0031] The internal fibrous web of the elastic band may have a basis weight of 5 g / m 2 to 45 g / m 2 and the external fibrous web may have a basis weight of 10 g / m 2 to 45 g / m 2 .

[0032] The elastic laminate may have an elongation rate of at least 110% in at least one direction.

[0033] The first fibrous web may form the internal fibrous web of the elastic band and may be hydrophilic.

[0034] Based on the total basis weight of the first fibrous web, the first fibrous web may comprise at least 50% by weight of fibers selected from the group consisting of natural fibers, regenerated cellulose fibers, and bio-based polymers, and combinations thereof.

[0035] Based on the total basis weight of the second fibrous web, the second fibrous web may comprise at least 50% by weight of fibers selected from the group consisting of natural fibers, regenerated cellulose fibers, and bio-based polymers, and combinations thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figures 1A to 1B is a schematic plan view showing an embodiment of the wearable article of the present invention facing the clothing surface, with the seams of the wearable article not joined and in a flat and unshrunk state.

[0037] Figures 2A to 2C is a schematic cross-sectional view of an embodiment of the wearable article of the present invention.

[0038] Figure 3 is a schematic diagram showing an NMR sensor.

[0039] Figure 4 is a schematic diagram showing a sample and equipment prepared for placement on an NMR MOUSE sensor.

[0040] Figure 5A is a schematic diagram showing the position of the sample holder determined by the top marker, with no sample in between.

[0041] Figure 5B Shows the position of the sample holder determined by the top marker, with a dry sample therebetween.

[0042] Figure 5C Shows the position of the sample holder determined with a wet sample in the absence of a top marker.

[0043] Figure 6A Shows the drying distribution characteristic diagram and the wetting distribution characteristic diagram of Comparative Example 1 (after 1 minute and 20 minutes).

[0044] Figure 6B Shows the drying distribution characteristic diagram and the wetting distribution characteristic diagram of Comparative Example 2 (after 1 minute, 10 minutes and 20 minutes).

[0045] Figure 6C Shows the drying distribution characteristic diagram and the wetting distribution characteristic diagram of Example 2 (after 1 minute, 10 minutes and 20 minutes).

[0046] Figure 6D Shows the drying distribution characteristic diagram and the wetting distribution characteristic diagram of Example 3 (after 1 minute, 10 minutes and 20 minutes).

[0047] Figure 7 Shows the SEM photograph of the second fibrous web having a first fibrous layer and a second fibrous layer, wherein the upper side is the first fibrous layer (polypropylene fibers), and the bottom side is the second fibrous layer (cotton fibers). The SEM photograph shows that the fibers of the second fibrous layer interpenetrate with the fibers of the first fibrous layer. It can also be seen that some fibers of the second fibrous layer pass through the first fibrous layer and out of the first surface.

[0048] Definitions

[0049] As used herein, the following terms shall have the meanings specified hereinafter:

[0050] "Wearable article" means an article that can be worn in the form of, for example, pants, adhesive diapers, incontinence briefs, feminine hygiene underwear, wound dressings, hospital gowns, etc. Preferably, the wearable article of the present invention is pants. The "wearable article" can be so constructed as to also absorb and contain various effluents discharged from the body such as urine, feces, and menstrual fluid. The "wearable article" can be used as an outer cover adapted to be joined to a separate disposable absorbent insert for providing an absorption and containment function, such as those disclosed in PCT Publication WO 2011 / 087503A.

[0051] As used herein, "adhesive diaper" and "pant" refer to absorbent articles generally worn around the lower body by infants and incontinent patients to encircle the waist and legs of the wearer and particularly adapted to receive and contain urine and feces. In a pant, as used herein, the longitudinal edges of the first and second waist regions are attached to each other to pre-form a waist opening and leg openings. A pant is generally applied to a wearer in a proper position by inserting the wearer's legs into the leg openings and pulling the pant absorbent article to a position near the lower body of the wearer. The pant can be pre-formed by any suitable technique, which includes but is not limited to joining the various parts of the absorbent article using releasable and / or non-releasable bonding portions (i.e., a permanent side seam is not intended to be torn before the pant is removed from the wearer for disposal). In a diaper, the waist opening and leg openings are only formed when the diaper is applied to a wearer by releasably attaching the longitudinal edges of the first and second waist regions to each other bilaterally using a suitable fastening system.

[0052] An "adhesive diaper" refers to a disposable absorbent article applied to a wearer by means of tapes.

[0053] As used herein, "disposable" is used in its ordinary sense, meaning an article that is disposed of or discarded after a limited number of uses over different periods of time (e.g., less than 20 uses, less than 10 uses, less than 5 uses, or less than 2 uses). If the disposable absorbent article is an adhesive diaper, pant, sanitary napkin, menstrual pad, or wet wipe for personal hygiene, the disposable absorbent article is most often intended to be disposed of after a single use. The absorbent articles described herein are disposable.

[0054] "Longitudinal" refers to a direction that extends substantially perpendicular from one waist edge of the article to the opposite waist edge and is generally parallel to the greatest linear dimension of the article. "Transverse" refers to a direction perpendicular to the longitudinal direction.

[0055] "Inner" and "outer" refer respectively to the relative positions of elements or the relative positions of the surfaces of an element or a group of elements. "Inner" means that during wear, an element or surface is closer to the body of the wearer than some other element or surface. "Outer" means that during wear, an element or surface is farther from the skin of the wearer than some other element or surface (i.e., the element or surface is closer to the clothing of the wearer, which may be worn over the article of the present invention).

[0056] "Body-facing" (also referred to herein as "skin-facing") and "garment-facing" refer to the relative position of an element or the relative position of the surface of an element or a group of elements, respectively. "Body-facing" means that during wear, the element or surface is closer to the wearer than another element of the same assembly. An example is the inner layer of the elastic laminate of the present invention, where the inner layer (an element of the elastic laminate) is closer to the wearer's body than the outer layer (another element of the elastic laminate). "Garment-facing" means that during wear, the element or surface is farther from the wearer than another element of the same assembly. The garment-facing surface may face another garment of the wearer (i.e., other than the wearable article), other items such as bedding, or the atmosphere. The "frontmost 200 microns" mentioned in the following NMR test method refers to a sub-thickness of the elastic laminate that starts from the skin-facing surface of the elastic laminate and extends through the thickness of the elastic laminate towards the garment-facing surface. The "rearmost 200 microns" mentioned in the following NMR test method refers to a sub-thickness of the elastic laminate that starts from the garment-facing surface of the elastic laminate and extends through the thickness of the elastic laminate towards the skin-facing surface.

[0057] "Proximal" refers to the part that is closer to the longitudinal center of the article, whereas "distal" refers to the part that is farther from the longitudinal center of the article.

[0058] "Film" refers to a sheet-like material where the length and width of the material are much greater than the thickness of the material. Typically, the film has a thickness of about 0.5 mm or less.

[0059] "Water-permeable" and "water-impermeable" refer to the permeability of the material within the intended use of the disposable absorbent article. Specifically, the term "water-permeable" refers to a layer or layered structure having pores, openings, and / or interconnected void spaces that allows liquid water, urine, or synthetic urine to permeate through its thickness without pressurization. In contrast, the term "water-impermeable" refers to a layer or layered structure through which liquid water, urine, or synthetic urine cannot permeate through its thickness without pressurization (except for natural forces such as gravity). According to this definition, a water-impermeable layer or layered structure may be vapor-permeable, i.e., may be "vapor-permeable".

[0060] "Hydrophilic" describes a substrate surface that can be wetted by an aqueous fluid (e.g., an aqueous body fluid) that can be deposited on these substrates. Hydrophilicity and wettability are generally defined in terms of a fluid's contact angle and moisture transmission time, for example, through a nonwoven fabric. This is discussed in detail in the publication of the American Chemical Society entitled "Contact angle, Wettability and Adhesion" (Copyright 1964) edited by Robert F. Gould. When the contact angle between the fluid and the surface is less than 90°, or when the fluid tends to spread spontaneously along the substrate surface, it can be said that the substrate surface is wetted by the fluid (i.e., hydrophilic), and these two conditions generally coexist. Conversely, if the contact angle is equal to or greater than 90° and the fluid cannot spread spontaneously along the fiber surface, the substrate is considered "hydrophobic". The contact angle test method used for the present invention is stated below.

[0061] "Extensibility" and "extensible" mean that the width or length of a component in a relaxed state can be extended or increased.

[0062] "Elastic" and "elasticized" mean that the assembly includes at least a portion made of an elastic material.

[0063] "Elongation" means the state in which a material is elongated from its initial relaxed length, i.e., an elongation of 10% means an elongation resulting in 110% of its initial relaxed length.

[0064] "Elongatable material", "extensible material", or "stretchable material" are used interchangeably and refer to a material that, when a biasing force is applied, can be stretched to an elongation of at least 10% (i.e., can be stretched to more than 10% of its initial length) without breaking or fracturing and shows minimal recovery when the applied force is released, i.e., the recovery is less than about 20% of its elongation, without completely breaking or fracturing, as measured by the EDANA method 20.2 - 89. In the event that such an elongatable material recovers at least 40% of its elongation when the applied force is released, the elongatable material will be considered "elastic" or "elasticized". For example, an elastic material with an initial length of 100 mm can be extended to at least 150 mm and, when the force is removed, retracts to a length of at least 130 mm (i.e., exhibits 40% recovery). In the event that the material recovers less than 40% of its elongation when the applied force is released, the elongatable material will be considered "non - elastic". For example, an elongatable material with an initial length of 100 mm can be extended to at least 150 mm and, when the force is removed, retracts to a length of at least 145 mm (i.e., exhibits 10% recovery).

[0065] As used herein, the term "nonwoven fibrous web" refers to a material that is a manufactured fibrous web / layer of oriented or randomly oriented fibers or filaments. The fibers can be of natural or man-made origin. Natural fibers can be selected from the group consisting of: wheat straw fibers, rice straw fibers, linen fibers, bamboo fibers, cotton fibers, jute fibers, hemp fibers, sisal fibers, bagasse fibers, Yucca filamentosa fibers, Miscanthus fibers, marine or freshwater algae / seaweed fibers, silk fibers, wool fibers, and combinations thereof. Another group of fibers can also be regenerated cellulose fibers, such as viscose fibers, Lyocell fibers rayon, modal, acetate fibers, acrylic fibers, cuprammonium rayon, regenerated protein fibers, etc. Preferably, the natural fiber or modified natural fiber is selected from the group consisting of: cotton fibers, bamboo fibers, viscose fibers, or mixtures thereof. Preferably, the natural fiber is cotton fiber. Synthetic fibers can be selected from the group consisting of: polyolefins (such as polyethylene, polypropylene, or combinations and mixtures thereof), polyethylene terephthalate (PET), co-PET, polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA), nylon (or polyamide), or mixtures or compositions thereof. Another option is to use superabsorbent fibers, such as SAF TM , which is a crosslinked terpolymer based on acrylic acid that is partially neutralized to its sodium salt and is commercially available from Technical Absorbents.

[0066] The fibers in the nonwoven fibrous web are consolidated by friction, and / or cohesion and / or adhesion, and / or by thermal bonding, pressure bonding, thermal and pressure bonding, and / or ultrasonic bonding, excluding paper and woven, knitted, tufted, and stitch-bonded products. The fibers can be staple fibers (e.g., in a carded nonwoven fibrous web) or continuous fibers (e.g., in a spunbond or meltblown nonwoven).

[0067] The nonwoven fibrous web can be formed by many processes, such as meltblowing, spunlacing, solvent spinning, electrospinning, and carding methods, and the fibers can be consolidated, for example, by hydroentangling (in a hydroentangled nonwoven fibrous web), through-air bonding (using hot air blown through the fiber layer in the thickness direction), needling, one or more bonding patterns and bond indentations produced by local compression and / or application of heat or ultrasonic energy, or combinations thereof. Alternatively or additionally, the fibers can be consolidated by using a binder. The binder can be provided in the form of binder fibers (which are subsequently melted) or can be provided in liquid form, such as a styrene-butadiene binder. The liquid binder is provided to the fibers (e.g., by spraying, printing, or foam application) and is subsequently cured to solidify.

[0068] The basis weight of the nonwoven fibrous web is typically expressed in grams per square meter (g / m 2 ).

[0069] In a spunlace nonwoven fibrous web, the fibers have been carded into a precursor web and then subjected to the spunlace process to cause the fibers to interlace and entangle with each other. The cohesion and entanglement of the fibers with each other can be achieved by causing a plurality of jets of water to pass under pressure through a moving tufted fabric or cloth and interlace the fibers with each other like knitting (also referred to hereinafter as "hydroentanglement"). Thus, the consolidation of the spunlace nonwoven fibrous web is essentially the result of hydroentanglement. As used herein, "spunlace nonwoven fibrous web" also refers to a nonwoven fabric formed from two or more precursor webs that are joined to each other by hydroentanglement.

[0070] Before two or more fibrous webs are joined into a single nonwoven fabric by hydroentanglement, they may have undergone a bonding process, such as heat and / or pressure bonding using, for example, patterned calender rolls and anvil rolls to impart a bonding pattern. However, the two or more fibrous webs are joined to each other only by hydroentanglement. Alternatively, the spunlace nonwoven fibrous web is a single fibrous web, i.e., it is not formed from two or more precursor webs. In another alternative, the spunlace nonwoven fibrous web of the present invention can be formed from a single precursor web with short fibers laid on the precursor web. The short fibers may not yet be consolidated into a self-supporting precursor web, but the fibers are laid loosely on the precursor web. The relatively loose short fibers are then joined to each other and entangled with the fibers of the underlying precursor web by (only) hydroentanglement. The spunlace nonwoven layer / web can be made from short fibers or continuous fibers (continuous fibers are commonly also referred to as filaments).

[0071] Through-air bonding (which can be used interchangeably with the term "air-through bonding") refers to a process of bonding short fibers or continuous fibers by forcing air through the nonwoven fibrous web, where the air is hot enough to melt the polymer of the fibers (or at least partially melt, or melt to a state where the fiber surfaces become sticky enough), or if the fibers are multicomponent fibers, where the air is hot enough to melt one of the polymers of the fibers making up the nonwoven fibrous web (or at least partially melt, or melt to a state where the fiber surfaces become sticky enough). The melting and re-solidification of the polymer provides the bonding between the different fibers.

[0072] "Comprising" or "including" are open-ended terms, each specifying the presence of a feature, e.g., a component, but not excluding the presence of other features known in the art or disclosed herein, e.g., elements, steps, components. These terms based on the verb "comprise" encompass the narrower term "consisting essentially of", which excludes any element, step, or ingredient that significantly affects the way the feature performs its function and is not mentioned; and encompass the term "consisting of", which excludes any element, step, or ingredient not specified. Detailed implementation mode

[0073] Elastic laminate for a wearable article

[0074] The elastic laminate included in the wearable article of the present invention includes a first fibrous web and a second fibrous web in a face-to-face relationship. Each of the first fibrous web and the second fibrous web constitutes the entire surface area of the elastic laminate.

[0075] The first fibrous web is a nonwoven fibrous web, which can be formed of at least 90% by weight (based on the total weight of the first fibrous web) of synthetic fibers. The first fibrous web can be formed of 95% by weight or 100% by weight of synthetic fibers. The synthetic fibers of the first fibrous web can be selected from the group consisting of polyethylene, polypropylene, polyester, polylactic acid (PLA), and mixtures and combinations thereof (such as copolymers of polyethylene and polypropylene).

[0076] The second fibrous web is formed by a first fibrous layer and a second fibrous layer. The fibers of the first fibrous layer can be less hydrophilic than the fibers of the second fibrous layer. The relationship that the fibers of the second fibrous layer have higher hydrophilicity than the fibers of the first fibrous layer includes the following cases: where the first fibrous layer is hydrophobic and the second fibrous layer is hydrophilic, or both the first fibrous layer and the second fibrous layer are hydrophilic (where the second fibrous layer has higher hydrophilicity).

[0077] Alternatively or in addition, the fibers of the first fibrous layer can have a smaller average fiber surface area / volume than the fibers of the second fibrous layer. A smaller average fiber surface area / volume (resulting in a smaller average surface area per volume of the fibrous layer) can be obtained, for example, by using thicker fibers or by using, for example, circular fibers as the fibers of the first fibrous layer and shaped and / or thinner fibers for the second fibrous layer. Shaped fibers can have all shapes known in the art, such as multilobal. Examples of shaped fibers can be Coolmax fibers. Very fine fibers can be obtained via splittable fibers (such as splittable multicomponent fibers). Natural fibers can also be irregular in shape, such as cotton fibers, thereby providing an increased average surface area per volume.

[0078] If any of the first fibrous web, the first fibrous layer, and / or the second fibrous layer of the second fibrous web is formed of a mixture of different fibers, the average surface area per volume of the fibrous layer or the fibrous web is respectively the average fiber surface area per volume of the different fibers used, as determined by the average fiber surface area per volume test described below.

[0079] The average surface area per volume of the second fiber layer can be at least 20 [1 / mm], more preferably at least 30 [1 / mm], more preferably at least 50 [1 / mm], more preferably at least 60 [1 / mm], and even more preferably at least 100 [1 / mm] higher than the average surface area per volume of the first fiber layer.

[0080] The first fiber layer and the second fiber layer are integrally joined to each other such that at least some of the fibers of the second fiber layer interpenetrate the fibers of the first fiber layer. The integral joining of the first fiber layer and the second fiber layer can be achieved, for example, by hydroentangling, i.e., the second fiber web can be a hydroentangled nonwoven fiber web.

[0081] The first fiber layer can be a preformed nonwoven material, such as a spunbond nonwoven material, which can be bonded with heat and / or pressure (spots), for example, by passing the layer between a pair of calender rolls, one of the pair of calender rolls can have protrusions extending outward from the surface of the roll to impart a pattern of bonding areas on the spunbond layer; one or both of the calender rolls can be heated. Alternatively, the preformed nonwoven material forming the first fiber layer can be a carded air-laid bonded nonwoven material. The second fiber layer can be formed from a short fiber web that is laid on the precursor nonwoven material forming the first fiber layer.

[0082] Alternatively, although less preferred, the second fiber layer can be a preformed nonwoven material, such as the first fiber layer described in the previous paragraph.

[0083] The first fiber layer and the second fiber layer can then be joined by hydroentangling.

[0084] If the first fiber layer is a spunbond nonwoven precursor fiber web, the fiber web can be spot-bonded by heat and / or pressure. At the bonding spots, the fibers of the spunbond nonwoven precursor fiber web can be fused together. The spot bonding can be relatively small, and the total bonding area can be relatively small. Since the fibers of the second fiber layer can more easily entangle and interpenetrate the fibers of the first fiber layer, such a nonwoven fiber web is considered more suitable for integrally joining with the second fiber layer. If the total bonding area and the individual spot bondings are too large, the first fiber layer may also break if the first fiber layer and the second fiber layer are integrally joined by hydroentangling.

[0085] The first fiber layer forms the first surface of the second fiber web, and the second fiber layer forms the second surface of the second fiber web. In the elastic laminate, the second surface faces the first fiber web, and the first surface faces away from the first fiber web.

[0086] The second fibrous web may form the inner fibrous web of the elastic laminate such that at least a portion of the first surface of the second fibrous web (i.e., the portion that forms the innermost surface of the wearable article) is in direct contact with the wearer's skin during use of the article. The first fibrous web may form the outer fibrous web of the elastic laminate. The outer fibrous web may form a portion of the outermost surface of the wearable article, i.e., the surface facing the wearer's clothing in use. If the outer fibrous web includes an extension folded over the inner fibrous web (described in more detail below), then the extension may contribute to the innermost surface of the wearable article.

[0087] Without being bound by theory, it is believed that the sweat management of the elastic laminate can be improved by establishing a capillary gradient within the elastic laminate to drive fluid away from the wearer's skin, i.e., from the inner skin-facing surface of the laminate towards the center of the elastic laminate. It is important to transport moisture away from the surface of the elastic laminate that is in direct contact with the skin. Thus, if the second fibrous layer of the second fibrous web has a higher capillary pressure than the first fibrous web and higher than the first fibrous layer of the second fibrous web, it allows sweat to be transported away from the skin side of the elastic laminate towards the middle section of the elastic laminate (relative to the thickness of the elastic laminate). It has been found that sweat transport towards the outer surface of the elastic laminate may be less desirable compared to the rapid fluid transport towards the center of the elastic laminate. The liquid can be transported to the outer surface of the elastic laminate at a lower rate from there, or it can be transported to the outer surface by evaporation. Thereby, the outer surface of the elastic laminate (i.e., the surface facing the clothing) can provide a relatively dry feeling (and is actually dry), while achieving a dry skin-facing surface and dry skin.

[0088] In addition, there is an increasing desire to use natural fibers in absorbent articles, such as cotton, silk, lyocell, viscose, and bamboo. Such use helps to improve the sustainability of the article and is also considered to be healthier and more comfortable for the skin compared to synthetic fibers. However, while natural fibers readily absorb fluids, such as the sweat of the wearer, they do not easily transfer the liquid to other layers. Thus, a nonwoven fibrous web using natural fibers may feel wet both on the wearer's skin and on the surface facing the wearer's clothing. However, it has been found that by using natural fibers in the layers forming the inside of the elastic laminate, the potential wet feeling on the skin or from the outside can be eliminated.

[0089] In addition, the presence of natural fibers such as cotton or viscose provides additional capacity for temporarily storing sweat until the sweat is transported away by evaporation: In fact, it is known that natural fibers such as cotton and viscose can absorb moisture within the fibers themselves at significantly higher levels than traditional synthetic fibers such as polypropylene or polyester. If desired, this mechanism for increasing temporary sweat storage can be further enhanced by including superabsorbent fibers. Adding natural fibers and / or superabsorbent fibers to the second fiber layer allows moisture to be temporarily retained in the middle of the elastic laminate, thereby masking the moisture on the surface of the wearer's skin and the outer surface (i.e., the surface facing the clothing). A test method for determining the moisture absorption capacity of the fiber web is presented below.

[0090] As is known in the field of porous media science, the capillary pressure of a fiber material (such as the first and second fiber webs of the elastic laminate of the present invention) is proportional to the average surface area / volume of the fibers contained in the fiber material and to the hydrophilicity of the fibers determined via the contact angle θ. Specifically, it is known that the capillary pressure is proportional to the cosine of the contact angle cosθ. In other words, a higher average surface area per volume results in a higher capillary suction or capillary pressure in the material (i.e., in the first and second fiber webs). Similarly, a higher hydrophilicity (and a higher cosθ) also results in a higher capillary suction or capillary pressure in this material (i.e., in the first and second fiber webs). Hydrophilicity and hydrophobicity are determined via the contact angle θ. A fiber web or fiber layer with a contact angle θ of 90° or less is hydrophilic, and a fiber web or fiber layer with a contact angle equal to or greater than 90° is hydrophobic. The lower the contact angle (below 90°), the higher the hydrophilicity of the fiber web or fiber layer; the higher the contact angle (above 90°), the higher the hydrophobicity of the fiber web or fiber layer.

[0091] Test methods for determining the contact angle θ and the average surface area per volume are described below. These parameters can be determined for the first fiber web and for the first and second fiber layers of the second fiber web.

[0092] The first and second fiber layers can each have a contact angle θ, and the first fiber web can have a contact angle θ. The cosine of the contact angle θ multiplied by the average surface area / volume of the second fiber layer (cosθ × average surface area / volume) can be higher than the cosine of the contact angle θ multiplied by the average surface area / volume of the first fiber web.

[0093] The (cosθ × average surface area / volume) of the second fiber layer can be at least 20 [1 / mm], more preferably at least 30 [1 / mm], even more preferably at least 50 [1 / mm], still more preferably at least 60 [1 / mm], and even more preferably at least 100 [1 / mm] higher than the (cosθ × average surface area / volume) of the first fiber web.

[0094] The (cosθ × average surface area / volume) of the second fiber layer may be higher than that of the first fiber web by no more than 500 [1 / mm], or no more than 400 [1 / mm].

[0095] The cosine of the contact angle θ multiplied by the average surface area per volume of the second fiber layer may be higher than the cosine of the contact angle θ multiplied by the average surface area per volume of the first fiber layer.

[0096] The (cosθ × average surface area / volume) of the second fiber layer may be higher than that of the first fiber layer by at least 20 [1 / mm], more preferably at least 30 [1 / mm], even more preferably at least 50 [1 / mm], still more preferably at least 60 [1 / mm], and even more preferably at least 100 [1 / mm].

[0097] The (cosθ × average surface area / volume) of the second fiber layer may be higher than that of the first fiber layer by no more than 500 [1 / mm], or no more than 400 [1 / mm].

[0098] In addition, natural fibers or fibers with a higher average surface area per volume that may be present in the second fiber layer of the second fiber web may also be present in the first fiber layer of the second fiber web due to interpenetration and protrude from the first surface of the first fiber layer of the second fiber web. The protruding fibers may contact the skin and assist in transferring liquid from the skin to the second fiber web.

[0099] The contact angle highly depends on the hydrophilic / hydrophobic properties of the material. Thus, the fibers of the first fiber layer may be less hydrophilic than the fibers of the second fiber layer. The fibers of the first fiber layer may be hydrophobic, while the fibers of the second fiber layer may be hydrophilic. The relationship that the fibers of the second fiber layer have higher hydrophilicity than the fibers of the first fiber layer includes the following cases: where the first fiber layer is hydrophobic and the second fiber layer is hydrophilic. Alternatively, both the first fiber layer and the second fiber layer may be hydrophilic, where the second fiber layer has higher hydrophilicity.

[0100] Alternatively or in addition, the fibers of the first fiber layer may have a smaller average fiber surface area per volume than the fibers of the second fiber layer. The first fiber web may have a smaller average fiber surface area per volume than the fibers of the second fiber layer.

[0101] It has been found that the cosine of θ multiplied by the average surface area per volume (cosθ × average surface area / volume) is a good indication of the capillary pressure of the material, that is, the higher the value of the cosine of θ multiplied by the average surface area per volume, the higher the capillary pressure.

[0102] Therefore, it is desirable for the second fiber layer to have a higher (cosθ × average surface area / volume) value compared to the (cosθ × average surface area / volume) value of the first fiber layer.

[0103] It may also be desirable for the second fiber layer to have a higher (cosθ × average surface area / volume) value compared to the (cosθ × average surface area / volume) value of the first fiber web.

[0104] The second fiber layer can be a carded layer, and the fibers of the second fiber layer can be short fibers.

[0105] The first fiber layer can be a spunbond layer formed of continuous fibers. Alternatively, the first fiber layer can be a carded airlaid bonded layer formed of short fibers.

[0106] The first fiber layer and the second fiber layer can be integrally bonded to each other by hydroentangling. The fibers of the second fiber layer can be disposed on the surface of the first fiber layer, and subsequently, the fibers of the second fiber layer can be entangled with each other and with the fibers of the first fiber layer by applying a water jet to the fibers of the second fiber web (hydroentanglement). When the fibers of the first fiber layer are disposed on the second fiber layer, the fibers of the first fiber layer may not be pre-consolidated. For example, synthetic fibers such as polypropylene can form the first fiber layer (as a carded layer) of the second fiber web, while cotton fibers can form the second fiber layer (also as a carded layer) of the second fiber web. As used herein, "consolidated" means that the fibers of the fiber layer are not bonded to each other by, for example, providing a binder, by pressure, heat, or a combination thereof, and the fibers are not entangled with each other by other means such as by a water jet (referred to as hydroentanglement) or needling.

[0107] Conversely, although less preferred, the first fiber layer and the second fiber layer can be integrally bonded to each other by hydroentangling the fibers by providing the first fiber layer on the surface of the second fiber layer, and subsequently, the fibers of the first fiber layer can be entangled with the fibers of the second fiber layer by applying a water jet to the fibers of the second fiber web. When the fibers of the second fiber layer are disposed on the first fiber layer, the fibers of the second fiber layer may not be pre-consolidated.

[0108] As an alternative to hydroentangling, the fibers of the first fiber layer and the second fiber layer can be integrally bonded to each other by other known techniques such as needling.

[0109] It is preferred not to use adhesives (such as pressure-sensitive adhesives or hot-melt adhesives) and not to use binders to bond the first fiber layer and the second fiber layer.

[0110] At least 40%, or at least 50%, or at least 70%, or all of the surface area of the elastic laminate does not include any additional material layers other than the first fibrous web and the second fibrous web. When the elastic laminate is stretched such that the first fibrous web and the second fibrous web are flattened, or such that the first fibrous web or the second fibrous web is flattened, the average surface area is measured if it is not possible to further elongate without breaking or rupturing one of the first fibrous web or the second fibrous web. If one of the first fibrous web or the second fibrous web includes an extension folded onto the corresponding other of the first fibrous web and the second fibrous web, thereby providing a region in the elastic laminate having three fibrous webs (i.e., the first fibrous web, the second fibrous web, and the extension of the first fibrous web or the second fibrous web) overlapping each other, the extension is not considered an "additional material layer". Similarly, elastic strands are not considered additional material layers. An additional material layer is a material provided in addition to the first fibrous web and the second fibrous web (including any extensions) and having a significant average surface area, such as a film, an additional nonwoven fibrous web, or paper.

[0111] The second fibrous layer may comprise natural hydrophilic fibers, modified natural hydrophilic fibers, or a combination thereof. The second fibrous layer may be formed entirely of such natural hydrophilic fibers, modified natural hydrophilic fibers, or a combination thereof. Alternatively, the second fibrous layer may comprise at least 25 wt%, 50 wt%, or at least 70 wt%, or at least 90 wt%, or at least 95 wt% of natural hydrophilic fibers, modified natural hydrophilic fibers, hydrophilic synthetic fibers, or a combination thereof, based on the total weight of the second fibrous layer. Based on the total weight of the second fibrous layer, at least 25 wt%, 50 wt%, 70 wt%, 90 wt% or at least 95 wt% are hydrophilic fibers. Preferably, all the fibers of the second fibrous layer are hydrophilic fibers.

[0112] All the fibers of the first fibrous layer may be synthetic fibers, such as hydrophobic or hydrophilic synthetic fibers. Alternatively, synthetic fibers such as hydrophobic synthetic fibers may form at least 90 wt% or at least 95 wt% (based on the total weight of the first fibrous layer) of the first fibrous layer.

[0113] When the fibers of the first fibrous layer and the second fibrous layer are integrally bonded to each other (e.g., by hydroentangling), the amount of natural hydrophilic fibers and / or modified natural hydrophilic fibers may gradually increase through the thickness of the second fibrous web from the first surface of the second fibrous web to the second surface of the second fibrous web.

[0114] The natural hydrophilic fibers or modified natural hydrophilic fibers of the second fibrous layer may be selected from the group consisting of cotton, bamboo, viscose fiber, cellulose, silk, or mixtures or combinations thereof. Preferred modified natural hydrophilic fibers are regenerated cellulose fibers. For example, viscose fiber is a modified natural hydrophilic fiber made from regenerated cellulose fibers such as cellulose fibers from wood or bamboo or cotton.

[0115] In the second fibrous web, the basis weight ratio of the first fibrous layer to the second fibrous layer can be from 0.2 to 3, or from 0.2 to 2, or from 0.5 to 1.5, or from 0.5 to 1.

[0116] The first fibrous web can be a breathable bonded carded nonwoven fibrous web. Alternatively, the first fibrous web can be a spunbond fibrous web. If the first fibrous web is a spunbond fibrous web, the fibrous web can be bonded by heat and / or pressure (points).

[0117] Elastic laminate for use as a strap of a wearable article

[0118] The first fibrous web can form the inner fibrous web of the elastic laminate, while the second fibrous web can form the outer fibrous web of the elastic laminate. Alternatively, the second fibrous web can form the inner fibrous web of the elastic laminate, while the first fibrous web can form the outer fibrous web of the elastic laminate. The elastic laminate can form a belt of a wearable article such as a pant. The pant can be a disposable pant. Wearable articles are described in more detail below.

[0119] If the elastic laminate forms a belt of a wearable article (e.g., a disposable pant), then at least a portion of the inner fibrous web will be in direct contact with the skin of the wearer when the article is applied to the wearer, i.e., it will form at least a portion of the innermost surface of the wearable article. The outer fibrous web can form at least a portion of the outermost surface of the wearable article, which portion will generally be in contact with the wearer's clothing and may often be touched by a caregiver.

[0120] The first fibrous web and the second fibrous web can be directly joined to each other in an area of about 5% to about 50%. By "directly joined" it is meant that the inner fibrous web and the outer fibrous web are directly fixed to each other by applying an adhesive, ultrasonic waves, pressure, heat, or a combination thereof. The area percentage of the inner fibrous web and the outer fibrous web that are directly joined to each other can vary depending on the joining method used to form the elastic laminate, as discussed in further detail below. The inner fibrous web and the outer fibrous web can be directly joined to each other in an area of about 5% to about 50% to provide suitable sweat management properties while also helping to maintain the integrity of the elastic laminate.

[0121] According to the measurements herein, the outer fibrous web of the elastic laminate can have a plurality of openings with an opening ratio of about 5% to about 50%. By further providing a certain opening area for the outer fibrous web, a plurality of moisture transport channels are provided, which can contribute to effective liquid removal and transport to the outer fibrous web. The transport channels can be driven by a capillary force gradient and enhance the exposure of the outside of the laminate away from the skin.

[0122] Moreover, to provide a thickness gradient, the basis weight of the inner fibrous web can be no greater than that of the outer fibrous web. The inner fibrous web of the present invention is a nonwoven fibrous web, which can have a basis weight of about 5 g / m 2 to about 45 g / m 2 or about 5 g / m 2 to about 35 g / m 2 of basis weight.

[0123] The first fibrous web and the second fibrous web can have a fiber diameter of 1 μm to 35 μm. The first fibrous web and / or the second fibrous web can also include nanofibers with a fiber diameter less than 1 μm. As is known in the industry, the fiber diameter can also be expressed in denier per filament (dpf), which is grams per 9,000 meters of fiber length. In the second fibrous web, the fiber diameter of the second fiber layer can be less than that of the first fiber layer and the first fibrous web.

[0124] If the inner fibrous web is the first fibrous web, the inner fibrous web can be made by methods such as spunbonding, hydroentangling, carding or air-laying; and can include fibers and / or filaments made of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polylactic acid / polylactide (PLA) or conjugate fibers (such as PE / PET, PE / PP, PE / PLA), as well as natural fibers (such as cotton) or regenerated cellulose fibers (such as viscose fiber or lyocell fiber). If the inner fibrous web is the first fibrous web, the inner fibrous web can be made of biodegradable materials or derived from renewable resources. Non-limiting examples of materials suitable for the inner fibrous web of the present invention include: a 12-30 gsm breathable carded nonwoven substrate made of PE / PET bicomponent staple fibers, such as those purchased from Beijing Dayuan Nonwoven Fabric Co., Ltd. or Xiamen Yanjan New Material Co., Ltd.; and an 8-30 gsm spunmelt nonwoven substrate containing PP monofilaments or PE / PP bicomponent fibers, such as those purchased from Fibertex or Fitesa.

[0125] If the internal fibrous web is the first fibrous web, the internal fibrous web may preferably be relatively hydrophilic. If the external fibrous web includes an extension portion folded over the internal fibrous web, a certain degree of hydrophilicity may contribute to transporting away from the wearer's skin through the extended folded portion of the external fibrous web, which is at least partially not in direct contact with the wearer's skin. However, alternatively, although less preferred, if the internal fibrous web is the first fibrous web, the internal fibrous web may be inherently hydrophobic. Hydrophobicity can be provided to the internal fibrous web by treating the polymer resin with a hydrophobic molten additive during fiber preparation or by applying a hydrophobic additive after the nonwoven material is formed.

[0126] The hydrophobic additive may be a fatty acid derived from plant, animal, and / or synthetic sources. The fatty acid can be a C 8 -C 30 fatty acid, or a C 12 -C 22 fatty acid, or a substantially saturated fatty acid. The hydrophobic additive may be a fatty acid derivative, including fatty alcohols, fatty acid esters, and fatty acid amides. Suitable fatty alcohols include those derived from C 12 -C 30 fatty acids. Suitable fatty acid esters include those derived from a mixture of C 12 -C 30 fatty acids and a short-chain monohydric alcohol, preferably those fatty acid esters derived from a mixture of C 12 -C 22 saturated fatty acids and a short-chain monohydric alcohol. The hydrophobic molten additive may include a mixture of mono-fatty acid esters, di-fatty acid esters, and / or tri-fatty acid esters. Examples include fatty acid esters of glycerol having at least one alkyl chain, at least two or three chains attached to the glycerol to form monoglycerides, diglycerides, or triglycerides. Suitable triglycerides include glyceryl behenate, glyceryl tristearate, glyceryl tripalmitate, and glyceryl trimyristate, and mixtures thereof. Exemplary hydrophobic molten additives include glyceryl tristearate, such as those commercially available under the trade name Techmer PPM15000. The hydrophobic agent may be a fatty acid amide, including those derivatives obtained from a mixture of C12-C28 fatty acids (saturated or unsaturated) and primary or secondary amines such as erucamide, oleamide, and behenamide.

[0127] Exemplary hydrophobic additives that can be applied after the nonwoven material is formed include surfactants and silicone-based finishing agents, natural oils or waxes such as cottonseed oil, beeswax, and shea butter.

[0128] According to the measurements of the present invention, the internal fibrous web may optionally have a plurality of openings with an opening ratio of about 5% to about 30%, or about 5% to about 15%, or about 6% to about 8%, or about 7% to about 15%, or about 9% to about 25%, and an effective opening area of 0.1 mm 2 to about 25 mm 2 or about 0.1 mm 2 to about 10 mm 2 or about 0.5 mm 2 to about 4 mm 2 or about 4.0 mm 2 to about 8 mm 2 or about 7 mm 2 to about 15 mm 2 .

[0129] The external fibrous web of the elastic laminate may have a basis weight of about 10 g / m 2 to about 45 g / m 2 or about 10 g / m 2 to about 35 g / m 2 and may be adjusted such that the basis weight of the internal fibrous web is greater than, equal to, or less than the basis weight of the external fibrous web. If the external fibrous web is the first fibrous web, the external fibrous web may be made by methods such as spunbonding, hydroentangling, carding or air-laying; and may include fibers and / or filaments made of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polylactic acid / polylactide (PLA) or conjugate fibers (such as PE / PET, PE / PP, PE / PLA), as well as natural fibers (such as cotton) or regenerated cellulose fibers (such as viscose or lyocell). Additionally, if the external fibrous web is the first fibrous web, the external fibrous web may be made of biodegradable materials or derived from renewable resources.

[0130] The hydrophilic additive may be a polypropylene and polyethylene polymer, such as those purchased from Techmer PM (Clinton, TN, US) sold under the trade names Techmer PPM15560, TPM12713, PPM19913, PPM 19441, PPM19914, and PM19668. The hydrophilic additive may include anionic surfactants, cationic surfactants, amphoteric surfactants, or mixtures thereof. Exemplary hydrophilic additives include 100410AF PE MB sold by Ampacet, Irgasuf HL560 commercially available from Ciba Speciality Chemicals Inc., Hydrosorb 1001 commercially available from Goulston Technologies Inc., Cirrasol PP682 commercially available from Uniqema, Stantex S 6327 commercially available from Cognis, Silastol PST, Silastol PHP26 commercially available from Schill & Seilacher, Silwet L-7608 commercially available from Momentive Performance Materials, and silicone surfactants having a polyethylene oxide chain and a molecular weight above 700 g / mol commercially available from Polyvel Inc under the trade names Polyvel S-1416 or VW 315.

[0131] If the outer web is the first web, exemplary materials for the outer web include: an air-permeable carded nonwoven material having a thickness of at least about 50 μm, or at least about 80 μm, or at least about 200 μm. The thickness may be less than 2000 μm, or less than 1500 μm, or less than 1250 μm. Such materials may provide a soft and bulgy feeling for the web facing the clothes. If the outer web is the first web, suitable for the outer web of the present invention is an air-permeable carded nonwoven material made of co-centered bicomponent fibers, crimped fibers made of core-eccentric bicomponent filaments or side-by-side bicomponent filaments. Non-limiting examples of materials suitable for the outer web include: 12 g / m 2 to 45 g / m 2 an air-permeable carded nonwoven substrate comprising PE / PET bicomponent fibers, such as those purchased from Beijing Dayuan Nonwoven Fabric Co., Ltd. or Xiamen Yanjan New Material Co., Ltd.; and a spunbond nonwoven substrate having a weight of 8 - 45 gsm and comprising PP monofilaments or PE / PP bicomponent fibers, such as those purchased from Fibertex or Fitesa.

[0132] The basis weight and material thickness of the internal fiber web and the external fiber web of the present invention relate to materials obtained from the finished product according to "Preparation for Thickness and Basis Weight" below and measured respectively by the "Standard Test Method ASTM D 654 for Thickness of Paper and Paperboard" (with the load modified to 500 Pa) and by "Basis Weight - ASTM D 756 Practice for Determining the Weight and Shape Changes of Plastics under Accelerated Service Conditions". The total thickness of the elastic laminate is determined by the NMR MOUSE test method shown below.

[0133] According to the measurements herein, the external fiber web may have a plurality of openings with an opening ratio of about 5% to about 50%, or about 5% to about 30%, or about 7% to about 15%, or about 9% to about 25%, and an effective opening area of about 0.1 mm 2 to about 25 mm 2 or about 0.4 mm 2 to about 2.0 mm 2 or about 1.0 mm 2 to about 5 mm 2 or about 4.0 mm 2 to about 8 mm 2 or about 7 mm 2 to about 15 mm 2 .

[0134] Alternatively or in addition, according to the measurements herein, the internal fiber web may have a plurality of openings with an opening ratio of about 5% to about 50%, or about 5% to about 30%, or about 7% to about 15%, or about 9% to about 25%, and an effective opening area of about 0.1 mm 2 to about 25 mm 2 or about 0.1 mm 2 to about 10 mm 2 or about 0.4 mm 2 to about 2.0 mm 2 or about 0.5 mm 2 to about 4 mm 2 or about 1.0 mm 2 to about 5 mm 2 or about 4.0 mm 2 to about 8 mm 2 or about 7 mm 2 to about 15 mm 2 .

[0135] For the external fibrous web and / or the internal fibrous web, the openings can be open holes, slits, etc. Preferably, the openings are open holes. If the internal fibrous web and the external fibrous web have openings, the openings of the internal fibrous web can coincide with the openings of the external fibrous web. Alternatively, if the internal fibrous web and the external fibrous web have openings, the openings of the internal fibrous web may not coincide with the openings of the external fibrous web. In yet another alternative, if the internal fibrous web and the external fibrous web have openings, some of the openings in the internal fibrous web can coincide with the openings in the external fibrous web, while the remaining openings in the internal fibrous web may not coincide with the openings of the external fibrous web.

[0136] The openings in the internal fibrous web and / or the external fibrous web can be open holes having an aspect ratio of less than about 5. The aspect ratio of the openings is determined accordingly. Measure the maximum dimension of the opening, wherein the direction of the maximum dimension defines a first axis. A line perpendicular to the first axis defines a second axis. Measure the dimension of the opening along the second axis and define the transverse dimension. The aspect ratio is the maximum dimension divided by the transverse dimension.

[0137] The openings can be made by male and female hot pin methods, punching methods, hydroentangling methods using water spray and screens to create holes, and combinations thereof. The openings can be made by forming a plurality of weakened positions by heating or pressure and then incrementally stretching, causing the nonwoven fibrous web to rupture at the weakened positions, as described in U.S. Patent 5,628,097. Such rupture methods can be particularly useful for nonwoven materials using spunbond fibers and meltblown fibers. The openings can be three-dimensional, non-uniform, misaligned, and form a pattern as described in PCT Publication WO 2016 / 73712.

[0138] The internal fibrous web or the external fibrous web can be without openings (alternatively, both layers can be without openings). That is, according to the measurements herein, the combination of the internal fibrous web and the external fibrous web can provide a relative opening rate of 100%, less than 100%, or less than about 50%, or less than about 15%. The so-called relative opening rate means the percentage of the openings of the elastic laminate that match the openings of the external fibrous web. When there are openings only in the external fibrous web, the relative opening rate is 0%, whereas when the openings of the external fibrous web completely match the openings of the internal fibrous web, the relative opening rate is 100%. In the present invention, the internal fibrous web can optionally have openings, and when so, the pattern and density of the openings can be varied to completely or partially match the openings of the external fibrous web.

[0139] The inner fibrous web and the outer fibrous web can be directly joined to each other in an area of about 5% to about 50% by any means known in the art, such as by applying an adhesive, ultrasonic waves, pressure, or heat, to provide the elastic laminate of the present invention. The inner fibrous web and the outer fibrous web can be directly joined at least in part by an adhesive. When an adhesive is used to join the inner fibrous web and the outer fibrous web, the area where the adhesive is applied between the inner fibrous web and the outer fibrous web is considered the area where the fibrous webs are directly joined. When using an adhesive as the joining means, the adhesive can be applied intermittently, such as in a spiral pattern. Alternatively or in addition, for better process control, the adhesive can be applied by a slot coating pattern, where the area of adhesive application is about 5% to about 50%, or about 5% to about 40%, or about 5% to about 30% of the planar area of the laminate. Alternatively or in addition, the inner fibrous web and the outer fibrous web can also be directly joined at least in part by directly joining the fibers of the inner fibrous web and the outer fibrous web, such as by heat, pressure, or ultrasonic waves.

[0140] The elastic laminate of the present invention can have an elongation rate of at least about 110% in at least one direction. Elasticity can be imparted by laminating an elastomer between the inner fibrous web and the outer fibrous web. The elastomer can preferably be a plurality of elastic strands, but can also alternatively be an elastic strip or an elastic sheet. The fibrous web and the elastomer can be joined at least in part by a method selected from the following: adhesives, heat, pressure, ultrasonic waves, and combinations thereof. See Figure 1B , an adhesive can be applied to join the elastomer to the outer fibrous web and / or the inner fibrous web, and can also be applied via slot coating in the pattern of side panel adhesive 233 for joining the outer fibrous web and the inner fibrous web. Alternatively or in addition, the elastomer can be joined by deforming the inner fibrous web and / or the outer fibrous web in contact with the elastomer via ultrasonic waves or heat to anchor the elastomer against the inner fibrous web and / or the outer fibrous web. Although less preferred, the elastomer can be an elastic sheet; where ultrasonic waves are applied to the combined inner fibrous web, outer fibrous web, and elastic sheet at a certain energy level such that the fibers of the inner fibrous web and the outer fibrous web are in direct contact with each other. These direct joining areas of the fibers are also considered the areas where the inner fibrous web and the outer fibrous web are directly joined.

[0141] The elastic laminate obtained by any of the foregoing joining methods does not require more force than that required to at least partially directly join the laminate to be embossed or mechanically activated. Thus, the elastic laminate can be prepared economically. The direct joining area can be measured by appropriately stretching the elastic laminate to an unshrunk state with a force of 25 N and observing the planar area where the inner layer and the outer layer are directly joined.

[0142] Wearable article

[0143] The present invention relates to a wearable article comprising an elastic laminate. The elastic laminate can form at least a part of the wearable article that is in direct contact with the skin.

[0144] If used as an elastic band of a wearable article, the elastic laminate comprises an inner fibrous web and an outer fibrous web. When the article is worn, the inner fibrous web is closer to the wearer than the outer fibrous web. When the article is worn, the inner fibrous web can be in direct contact with the wearer's skin. The outer fibrous web can form at least a part of the outer surface of the wearable article.

[0145] Generally, the elastic laminate can be used as a component selected from the following: an elastic band of a wearable article, a waistband, side panels, leg cuffs, and an outer covering.

[0146] The elastic laminate of the present invention can be particularly used as an elastic band. The wearable article can be a pair of pants. An exemplary pair of pants is described in PCT Publication WO 2006 / 17718A. The pants can include a central infrastructure 38 for covering the crotch region of the wearer when the article is worn, a front band 84 and a rear band 86 (hereinafter referred to as "the front band and the rear band") comprising the elastic laminate of the present invention, and the front band 84 and the rear band 86 form a discrete annular elastic band 40 (hereinafter referred to as "the waistband"), and the annular elastic band extends transversely to define a waist opening. The wearable article 20 can be a one-piece pants, wherein the central infrastructure 38 is continuous with the front band 84 and the rear band 86, and the leg openings are formed continuously (not shown). A banded pants can be advantageous because the central infrastructure 38 has better breathability, thus providing better sweat management for the entire wearable article.

[0147] Figure 1A A perspective view showing an example of the wearable article of the present invention for a pair of pants facing the clothing surface, the seams of the wearable article are not joined and in a flat and unshrunk state. The wearable article has a longitudinal center line L1 that also serves as a longitudinal axis, and a transverse center line T1 that also serves as a transverse axis. The wearable article has a body-facing surface, a clothing-facing surface, a front region 26, a rear region 28, a crotch region 30, and seams that join the front region 26 and the rear region 28 to form two leg openings and a waist opening. Since each of the first fibrous web and the second fibrous web is included in the entire surface area of the elastic laminate, the seams also include both the first fibrous web and the second fibrous web, that is, the front band 84 and the rear band 86. At least a part or all of the front band 84, or at least a part or all of the rear band 86, or the entire discrete annular elastic band 40 can be made of the elastic laminate of the present invention. The front band 84, the rear band 86, and the central infrastructure 38 together define the leg openings.

[0148] As Figure 1A and 2AAs shown in Figure 2C, the central base structure 38 may include a backsheet 60 and an outer cover layer 42 for covering the outer side of the backsheet 60. The backsheet 60 may be a water-impermeable film. At least a portion or all of the outer cover layer 42 may be the elastic laminate of the present invention. The central base structure 38 may include an absorbent core 62 disposed on the central base structure 38 for absorbing and containing body exudates. Figure 1A As illustrated, the central base structure 38 may have a generally rectangular shape, left and right longitudinally extending side edges 48 (hereinafter referred to as "side edges"), and front and rear transversely extending end edges 50 (hereinafter referred to as "end edges"). The central base structure 38 also has a front waist panel 52 positioned in the front region 26 of the wearable article, a rear waist panel 54 positioned in the rear region 28, and a crotch panel 56 located between the front waist panel 52 and the rear waist panel 54 in the crotch region 30. The center of the front band 84 is joined to the front waist panel 52 of the central base structure 38, and the center of the rear band 86 is joined to the rear waist panel 54 of the central base structure 38, and the front band 84 and the rear band 86 each have a left side panel and a right side panel 82 in which the central base structure 38 does not overlap. The central base structure 38 may include one or more leg cuffs on each side for forming a gasket for the leg opening. At least a portion of the leg cuffs or at least one or all of them may be the elastic laminate of the present invention.

[0149] Although not shown, the wearable article of the present invention may be a taped diaper having a longitudinal axis, a longitudinal axis, a body-facing surface, and a clothing-facing surface. The wearable article may have a central infrastructure, which includes a front region, a rear region, and a crotch region each defined by a laterally extending line assumed to be separated by 3 equal lengths along the longitudinal axis. The front region and / or the rear region may have a fastening member for fastening the article to construct a waist opening and leg openings. The waist opening may include a waistband. The fastening member may be made of the following components: a connecting member connected to the central infrastructure, a stretchable side piece that can be stretched laterally, and a fastening member with an engaging element such as a hook. The front region and / or the rear region may be provided with a landing zone for receiving the engaging element of the fastening member. The landing zone may be a loop that can be engaged with a hook. At least a portion or all of the waistband, side piece, or landing zone of the wearable article may be an elastic laminate of the present invention.

[0150] The annular elastic band 40 of the pants of the present invention serves to dynamically generate an adhesion force and distribute the dynamically generated force during wearing. The proximal edge 90 is positioned closer to the crotch piece 56 of the central infrastructure 38 than the distal edge 88. The front band 84 and the rear band 86 can be joined to each other only at the side edges 89 at the seams to form a wearable article having a waist opening and two leg openings. Each leg opening can be provided with elasticity around the perimeter of the leg opening. For banded pants, the elasticity around the leg opening can be provided by a combination of the elasticity from the front band 84, the rear band 86, and any elasticity from the central infrastructure 38.

[0151] The front band 84 and the rear band 86 of the pants are configured to impart elasticity to the band 40. The front band 84 and the rear band 86 can each be formed of the elastic laminate of the present invention, which includes a plurality of elastomers 96 extending in the transverse direction, an internal fiber web 94, and an external fiber web 92. Optionally, an external sheet fold 93, which is an extension of the external fiber web ( = second fiber web), can be formed by folding the extension of the external fiber web. Alternatively, although not preferred, an internal sheet fold 95, which is an extension of the internal sheet, can be formed by folding the internal sheet. The external fiber web 92 can be made of the same nonwoven substrate of the present invention as the outer covering layer 42 to provide an overall aesthetic and tactile feel to the article. Preferably, an external fiber web fold is provided around the waist opening 88 of the wearable article.

[0152] When the central infrastructure 38 includes an absorbent core, some or all of the regions of the front band 84 or the rear band 86 that overlap the absorbent core can be made non-elastic. See Figure 1A , where the regions of the front waist panel 52 and the rear waist panel 54 where the elastomers 96 are ineffective are shown in white. For example, as seen in the rear band 86, the elastomers 96 that overlap the non-existing region 61 of the absorbent material and face the distal edge of the absorbent core 62 can be provided with effective elasticity to achieve a good fit of the central infrastructure 38. This may be advantageous for preventing leakage.

[0153] Providing the outer folds 95, 93 helps to avoid the waist opening 88 terminating in the sharp edges of the front band 84 or the rear band 86. In addition, any elastomers 96 in the front band 84 or the rear band 85 can be set at least about 2 mm, or about 5 mm to about 9 mm, away from the waist opening to avoid sharpness of the waist opening and also ensure that any elastomers are not accidentally exposed during manufacturing or use. The external fiber web folds 95, 93 can extend towards the proximal edge of the band such that there is an overlap of at least about 10 mm, or at least about 15 mm, between the central infrastructures 38 to ensure the integrity between the front band 84 and / or the rear band 86 and the central infrastructure 38.

[0154] See Figure 2A, the front panel 84 and / or the back panel 86 may include an outer web fold 93, where the outer web fold 93 is an extension of the outer web, and the outer web fold 93 is formed by folding an extended portion of the outer web at the distal edge 88 of the panel. When the front panel 84 and / or the back panel 86 are formed from the elastic laminate of the present invention, the outer web extends beyond the elastic laminate and is folded over the inner web such that at least a portion of the elastic panel includes a layer of the inner web sandwiched between two layers of the outer web.

[0155] See Figure 1A , the lateral width LW of the back panel 86 in the unshrunk state may be the same as the lateral width of the front panel 84 in the same state. Such articles can be prepared economically. The longitudinal length LB of the back panel 86 between the back distal edge 88 and the back proximal edge 90 along the entire width LW of the back panel 86 may be substantially the same as the longitudinal length LF of the front panel 84 between the front distal edge 88 and the front proximal edge 90. In such a configuration, the side edges 89 of the front panel 84 and the back panel 86 of the same length are joined at the seam to form the article. Such articles can be prepared economically. The back panel 86 may have a greater longitudinal length LB transversely between the back distal edge 88 and the back proximal edge 90 along the entire width LW of the back panel 86 compared to the longitudinal length LF of the front panel 84 between the front distal edge 88 and the front proximal edge 90. In such a configuration, when the wearable article is assembled to form a waist opening and leg openings, the wearable article is folded along the transverse centerline T1 such that the front distal edge 88 is aligned with the back distal edge 88. The front side edge 89 is also aligned with a portion of the back side edge 89. Then the front panel 84 and the back panel 86 are joined at the seam at the front and back side edges 89. However, the front proximal edge and the back proximal edge 90 may not be aligned with each other. The back proximal edge 90 may be disposed longitudinally closer to the transverse centerline T1 than the front proximal edge 90 such that the proximal portion of the back panel 82 extends beyond the front proximal edge 90 towards the crotch panel 56 of the central infrastructure 38. The side edges of the proximal portion of the back panel 82 may not be joined to any part and do not contain attachments. Thus, the proximal portion of the back panel 82 provides buttock coverage.

[0156] See Figure 1A and 2A-2C, the front gusset 84 and the rear gusset 86 are discontinuous from each other in the crotch region 30 such that the outer cover layer 42 is the surface facing the garment in the crotch region 30. The outer cover layer 42 may extend longitudinally only partially along the front waist panel 52 and the rear waist panel 54 to leave distal portions of the front waist panel 52 and the rear waist panel 54 that do not include the outer cover layer 42. That is, the longitudinal length of the outer cover layer 42 may be longer than the longitudinal length of the crotch panel 56 and shorter than the longitudinal length of the backsheet 60. With such a configuration, the distal portions of the front waist panel 52 and the rear waist panel 54 lack the outer cover layer 42, thereby providing better breathability and sweat management for the elastic band 40. Additionally, this may provide cost savings in the material of the outer cover layer 42. Thus, observing the layers of elements between the surface facing the garment and the backsheet 60 of the central infrastructure 38, there is a transition zone 34 disposed on the front waist panel 52 and the rear waist panel 54 where the outer cover layer 42 is present. The longitudinal length of the transition zone 34 can be made as short as possible, for example, less than about 20 mm, or less than about 15 mm, or less than about 10 mm. Additionally, an adhesive can be applied over the entire area of the transition zone 34, or over the entire area that leaves a longitudinal distance not exceeding at most 5 mm from the distal edge of the transition zone 34. To provide an attractive artwork for the wearable article in an economical manner, printing can be provided on the side of the backsheet 60 facing the garment. By providing a transition zone 34 that is as short as possible, applying an adhesive to the transition zone 34 to enhance transparency, or simply avoiding showing the artwork in the transition zone 34, damage to the appearance of the artwork on different material layers between the artwork and the observer can be avoided. See Figure 1A , the artwork on the backsheet 60 can be printed in the regions 40F and / or 40B.

[0157] The article of the present invention provides improved sweat management characteristics, is easy to apply and comfortable to wear, while being manufactured economically.

[0158] Bio-based material

[0159] Using ASTM D6866 - 10, Method B, the elastic laminate may include a bio - based content value of about 10% to about 100%, or about 25% to about 75%, or about 50% to about 60%.

[0160] Using ASTM D6866 - 10, Method B, the first fiber web, the first fiber layer, and / or the second fiber layer of the elastic laminate may include a bio - based content value of about 10% to about 100%, or about 25% to about 75%, or about 50% to about 60%.

[0161] To apply the method of ASTM D6866-10 to determine the biobased content of a single-component material (i.e., an elastomeric laminate), the material is separated and cleaned such that the resulting sample reflects as closely as possible the composition of the starting material. For example, if the nonwoven component of an elastomeric nonwoven laminate is of interest, the laminate is deconstructed (removing the elastomeric strands), and the nonwoven layer is washed with a suitable solvent to remove any residual binder present. To apply the method of ASTM D6866-10 to a sample assembly of two or more materials with different or unknown compositions, the materials are ground into particulate form (particle size of about 20 mesh or smaller) by using a known grinding method (such as using a Wiley mill) to homogenize the sample. A representative sample of a suitable mass is then taken from the resulting sample of randomly mixed particles.

[0162] Verification of polymers derived from renewable resources

[0163] A suitable verification technique is by 14C analysis. A small fraction of the carbon dioxide in the atmosphere is radioactive. This 14C carbon dioxide is created when nitrogen is attacked by neutrons generated by ultraviolet light, causing the nitrogen to lose a proton and form carbon with a molecular weight of 14, which is immediately oxidized to carbon dioxide. This radioactive isotope represents a small but measurable fraction of the atmospheric carbon. Atmospheric carbon dioxide cycles through green plants to produce organic molecules during photosynthesis. The cycle ends when the green plants or other forms of life metabolize the organic molecules to produce carbon dioxide, which is released back into the atmosphere. Nearly all forms of life on Earth rely on green plants to produce organic molecules for growth and reproduction. Thus, the 14C present in the atmosphere becomes part of all life forms and their biological products. In contrast, fossil fuel-based carbon does not have the labeled radioactive carbon ratio of atmospheric carbon dioxide.

[0164] The assessment of the renewable-based carbon in a material can be performed by standard test methods. By using radiocarbon and isotope ratio mass spectrometry, the biobased content of a material can be determined. ASTM International (formerly known as the American Society for Testing and Materials) has established a standard method for assessing the biobased content of materials. This ASTM method is named ASTM D6866-10.

[0165] The application of ASTM D6866-10 to derive the "biobased content" is based on the same concept as radiocarbon dating but does not use the age equation. The analysis is performed by deriving the ratio of the amount of organic radioactive carbon (14C) in an unknown sample to the amount of radioactive carbon in a modern reference standard. This ratio is reported as a percentage, with "pMC" (percent modern carbon) as the unit.

[0166] The modern reference standard used in radiocarbon dating is the NIST (National Institute of Standards and Technology) standard, which has a known radiocarbon content equivalent to approximately the year 1950 AD. The year 1950 AD was chosen because it represents the time before thermonuclear weapon tests, which introduced large amounts of excess radiocarbon into the atmosphere with each explosion (the term "carbon explosion"). The reference for the year 1950 AD is expressed as 100 pMC.

[0167] Tests have shown that before the end of thermonuclear weapon tests, due to the "carbon explosion", the radiocarbon content in the atmosphere reached its peak in 1963, almost twice the normal level. After the distribution of the radiocarbon content in the atmosphere reached its peak, it has remained roughly constant, so that after the year 1950 AD, the biogenic radiocarbon content in plants and animals exceeded 100 pMC. Over time, it has been gradually reduced, and the current value is close to 107.5 pMC. This means that fresh biomass materials such as corn can give a radiocarbon label close to 107.5 pMC.

[0168] Combining fossil carbon with contemporary carbon in a material will result in dilution of the contemporary pMC content. Assuming that 107.5 pMC represents contemporary biomass materials and 0 pMC represents petroleum derivatives, the measured pMC value of the material will reflect the proportion of the two component types. A material that is 100% derived from contemporary soybeans should give a radiocarbon label close to 107.5 pMC. If the material is diluted with, for example, 50% petroleum derivatives, it will give a radiocarbon label close to 54 pMC (assuming that the petroleum derivatives have the same carbon percentage as soybeans).

[0169] The results of the biomass content are derived by setting 100% equal to 107.5 pMC and 0% equal to 0 pMC. In this regard, a sample with a measured value of 99 pMC will give an equivalent biobased content value of 92%.

[0170] The evaluation of the materials described herein can be carried out in accordance with ASTM D6866. The average values cited in this report cover an absolute range of 6% (±3% on either side of the biobased content value) to account for variations in the final component radiocarbon labels. It is assumed that all materials are modern materials or fossils in their initial state, and it is assumed that the desired result is the amount of the biological component "present" in the material, not the amount of biobased material "used" in the manufacturing process.

[0171] Test methods

[0172] Contact angle test method

[0173] A rectangular fibrous web sample measuring 1 cm × 2 cm is taken from the elastic laminate of the wearable article so as not to damage the structure of the material. The length (2 cm) of the sample is arranged parallel to the longitudinal centerline of the article. The sample of interest can be separated from other components of the wearable article, such as the internal fibrous web or the external fibrous web of the elastic laminate, the elastomer between the internal fibrous web and the external fibrous web, or the backsheet or any other material, by techniques such as applying a cryogenic spray or other suitable methods that do not permanently alter the properties of the fibrous web. The extracted fibrous web sample is conditioned at a temperature of 23 ± 2 °C and a relative humidity of 50 ± 10% for at least 24 hours. The sample is gently handled by the edges using tweezers and is flat-mounted on the SEM sample holder using double-sided tape. Multiple samples are prepared in a similar manner as needed to accumulate the required number of individual measurements.

[0174] The sample is sprayed with a fine mist of water droplets generated using a small hobby airbrush device. The water used to generate the droplets is distilled deionized water having a resistivity of at least 18 MΩ-cm. The airbrush is adjusted so that each droplet has a volume of approximately 2 pL. Approximately 0.5 mg of water droplets are deposited evenly and gently onto the sample. Immediately after the water droplets are applied, the mounted sample is immersed in liquid nitrogen for freezing. After freezing, the sample is transferred to a Cryo-SEM preparation chamber at -150 °C, coated with Au / Pd for 2 minutes, and transferred to a Cryo-SEM chamber at -150 °C. The Gatan Alto 2500 Cryo-SEM preparation chamber or an equivalent instrument is used as the preparation chamber. High-resolution images of the water droplets on the fibers are obtained using a Hitachi S-4700 Cryo-SEM or an equivalent instrument. The water droplets are randomly selected, but a droplet is suitable for imaging only if the orientation of the droplet in the microscope is such that the projection of the droplet extending from the fiber surface is approximately maximized. The contact angle between the water droplet and the fiber is determined directly from the image.

[0175] The above procedure is used for the first fibrous web to determine the first fibrous web contact angle. Ten water droplets located on the first fibrous web are imaged, thereby performing 20 contact angle measurements (once on each side of each imaged droplet), and the arithmetic mean of these 20 contact angle measurements is calculated and reported as the first fibrous web contact angle, accurate to 0.1 degree.

[0176] The above procedure is used for the first fibrous layer of the second fibrous web to determine the first fibrous layer contact angle of the second fibrous web. Ten water droplets located on the first fibrous layer of the second fibrous web are imaged, thereby performing 20 contact angle measurements (once on each side of each imaged droplet), and the arithmetic mean of these 20 contact angle measurements is calculated and reported as the first fibrous layer contact angle of the second fibrous web, accurate to 0.1 degree. Ten water droplets are analyzed from the fiber portion located within a certain distance from the first surface of the second fibrous web, where the distance is 20% of the thickness of the second fibrous web.

[0177] The above procedure is used for the second fiber layer of the second fibrous web to determine the contact angle of the second fiber layer of the second fibrous web. Ten droplets located on the second fiber layer of the second fibrous web are imaged, thereby performing 20 contact angle measurements (once for each side of each imaged droplet), and the arithmetic mean of these 20 contact angle measurements is calculated and reported as the contact angle of the second fiber layer of the second fibrous web, accurate to 0.1 degree. Ten droplets are analyzed from the fiber portions located within a certain distance from the second surface of the second fibrous web, where the distance is 20% of the thickness of the second fibrous web.

[0178] Moisture absorption capacity test method

[0179] The moisture absorption capacity C of the fibrous web can be measured as follows:

[0180] The fibrous web can be obtained as a raw material or removed from a wearable article. To remove it from a wearable article, multiple samples of the fibrous web are removed from the elastic laminate of the wearable article, taking care not to touch the surface of the samples or damage the structure of the material. Each sample can be separated from other components of the wearable article, such as the internal fibrous web or external fibrous web of the elastic laminate, the elastomer between the internal fibrous web and the external fibrous web, or the backsheet or any other material, by techniques such as applying a cryogenic spray or other suitable methods that do not permanently alter the properties of the fibrous web. Samples of the fibrous web can be removed from one sample of the wearable article, or combined from multiple samples of the same wearable article to extract approximately 1 g of the fibrous web. The extracted fibrous web samples are conditioned at a temperature of 23°C ± 2°C and a relative humidity of 50% ± 10% for at least 24 hours. The samples are gently handled by the edges using tweezers.

[0181] - Condition a fibrous web (sample) with a dry weight of approximately 1 g in a chamber at constant temperature and humidity (20°C, 60% RH) for 24 hours.

[0182] - Subsequently, allow the sample to absorb moisture in a chamber at constant temperature and humidity (40°C, 60% RH) for 2 hours. Immediately measure the wet mass (MWET) of the sample after 24 hours.

[0183] - Then dry the sample in an oven at a temperature of 105°C + / - 3°C and 60% RH for 24 hours.

[0184] - Measure the dry mass (MDRY) of the sample.

[0185] - Calculate the moisture absorption capacity C as (MWET - MDRY) / MDRY, in units of grams of moisture / gram of dry sample.

[0186] Average surface area / volume test method

[0187] The per volume average surface area method uses scanning electron microscopy (SEM) analysis to determine the per volume average surface area of each of one or more fiber layers present in a fiber web, and to determine the per volume average surface area of the entire fiber web, such as a first fiber web. SEM images that include front views and / or cross-sections of the fibers are used to measure the perimeter of the cross-sectional area of each individual fiber, which is considered to directly correspond to the surface area per volume ratio of these same fibers, thereby determining the per volume average surface area present in each layer or fiber web, respectively.

[0188] A rectangular fiber web sample measuring 1 cm × 2 cm is removed from the elastic laminate of the wearable article, taking care not to disrupt the structure of the material. The sample has a length (2 cm) aligned with the longitudinal centerline of the wearable article. The sample of interest can be separated from other components of the wearable article, such as a first fiber web and a second fiber web (if used as an elastic band, which can represent the inner fiber web or outer fiber web of the elastic laminate), the elastomer between the inner fiber web and the outer fiber web, or the backsheet or any other material, by techniques such as applying a cryogenic spray or other suitable methods that do not permanently alter the properties of the fiber web. The extracted fiber web sample is conditioned at a temperature of 23 ± 2 °C and a relative humidity of 50 ± 10% for at least 24 hours. The sample is gently handled by the edges using tweezers and is flat-mounted on an SEM sample holder using double-sided tape. Multiple samples are prepared in a similar manner as needed to accumulate a certain number of measurements. In the case of performing a cross-sectional analysis, as described below, a new single-edge razor blade (such as a 0.009" (0.22 mm) thick surgical carbon steel razor blade, part number 55411-050 from VWR, Radnor, PA, USA, or equivalent) is used to cross-section the sample before mounting it in the 2 cm dimension, and then one of the new cross-sections is analyzed in the SEM. Before introducing the sample into the SEM, each sample is sputter-coated with a gold or palladium compound to avoid charging and vibration of the fibers in the electron beam.

[0189] Use scanning electron microscopy (SEM) to analyze the top view and cross-section of the fibers.

[0190] Select a magnification of 500 to 10,000 times such that the ratio of the target fiber perimeter to the horizontal field width (HFW) is greater than 0.5. Secondary electron images are obtained using a standard Everhart-Thornley detector.

[0191] Capture an initial cross-sectional SEM image of the fibrous web of interest. If the fibers present have a circular cross-section, the fiber width measurements from the top-view image can be used as diameters, and for each diameter, the corresponding perimeter (circumference) is calculated assuming a circular cross-section. No fiber is measured more than once, and the surface area to volume of each measured fiber is recorded as the ratio of the perimeter to the area at that measurement point, i.e., πD / ((πD2) / 4) = 4 / D, where D is the measured fiber diameter. If the fibers present in the fibrous web do not have a circular cross-section, the area and perimeter of each fiber analyzed are measured directly from the SEM cross-sectional fibrous web image. Image analysis software, such as Image J (NIH, Bethesda, MD, USA, or equivalent), can be used to assist in accurately and easily measuring the cross-sectional perimeter. Record the perimeter and area of each measured cross-section, and the ratio of the perimeter to the area of each cross-section.

[0192] If the fibrous web of interest exhibits a gradient in fiber size and / or shape, each distinct fiber layer is characterized separately.

[0193] Make at least 100 individual fiber measurements for each fiber layer in the fibrous web of interest or throughout the fibrous web. Calculate the arithmetic mean of the recorded cross-sectional perimeter to area ratios between the fibers in each layer present and report it separately as the per volume average surface area of the fiber layer in the fibrous web of interest or of the fiber layer or fibrous web. The average surface area to volume ratio is reported in units of 1 / mm, accurate to 0.1 1 / mm.

[0194] Fiber diameter test method

[0195] The average equivalent fiber diameter of each fiber layer in one or more different fiber layers present in the fibrous web is determined by the per volume average surface area method. Once the per volume average surface area (SApV) of a given fiber layer is determined, the average equivalent diameter of that fiber layer is calculated as 4 / SApV. The average equivalent fiber diameter is recorded in micrometers (μm), accurate to 0.1 μm.

[0196] NMR MOUSE test method

[0197] NMR-MOUSE (Mobile Universal Surface Explorer) is a portable open NMR sensor equipped with a permanent magnet geometry that generates a highly uniform gradient perpendicular to the surface of the scanner (as Figure 3As shown). A frame 1007 made of glass fiber reinforced plastic supports the sample and remains stationary during testing. At the position defining the maximum depth penetrating into the sample, the flat sensitive volume of the sample is excited and detected by the surface of a coil 1012 placed on top of a magnet 1010. By repositioning the sensitive layer on the sample using a high-precision lifter 1008, the scanner can generate a one-dimensional feature map of the sample structure with high spatial resolution.

[0198] An exemplary instrument is the Profile NMR-MOUSE model PM25 with a high-precision lifter, purchased from Magritek Inc. (San Diego, CA). The requirements for the NMR-MOUSE are a resolution of 50 μm in the z-direction, a measurement frequency of 13.5 MHz, a maximum measurement depth of 25 mm, a static gradient of 8 T / m, and a sensitive volume (x-y dimension) of 40 mm × 40 mm. Before using the instrument, perform phase adjustment, check the resonance frequency, and check the external noise level according to the manufacturer's instructions. All measurements are carried out in a chamber controlled at 23 °C ± 1 °C and 50% ± 2% relative humidity.

[0199] Prepare the test solution: Prepare a 0.9 wt% / vol% saline solution by diluting 9.0 g of NaCl in 1 L of deionized water. Add 2 mM / L of gadolinium(III) dihydrogen ethylenediaminetetraacetate (purchased from SigmaAldrich). After addition, stir the solution at a rate of 160 rpm for one hour using an oscillator. Subsequently, check the solution to ensure that there are no remaining visible undissolved crystals. Before use, let the solution stand for 10 hours.

[0200] Before testing, condition the product to be tested at 23 °C ± 1 °C and 50% ± 2% relative humidity for two hours.

[0201] Identify the elastic laminate of the wearable article (e.g., if the elastic laminate forms an elastic band of the wearable article, at the back band) and cut a 100.0 mm × 100.0 mm sample from the elastic laminate. Ensure that only the elastic laminate is cut to obtain a flat sample 1022 on the frame. If the elastic laminate is attached to other components of the wearable article and the sample cannot be cut without separating the elastic laminate, the elastic laminate should be carefully separated from those other components by appropriate techniques, such as by applying type cold spraying, or other suitable methods that do not permanently alter the properties of the elastic laminate.

[0202] As Figure 4As shown, the sample 1022 is mounted on a frame 1023 made of polycarbonate, 80 mm × 80 mm × 20 mm high, with the surface of the outer fiber web (as specified in the Examples section below) facing up. On each edge, two pieces of double-sided tape 1024 are used to stretch the elastic laminate until the material is flat, i.e., the laminate shows no wrinkles. The frame has an opening area of 40 mm × 40 mm into which the top marker is inserted. The top marker consists of a block 1025 and a glass plate 1026. The block is made of polycarbonate, and the glass plate is mounted to the block 1025 using double-sided tape 1027 (the glass slide 1026 and the tape 1027 are shown in Figure 4 an enlarged size in

[0203] ). The block 1025 has dimensions of 40 mm × 40 mm corresponding to the size of the opening area in the frame 1023. The height of the polymer block is 30 mm. The glass plate 1026 has a thickness of 400 μm. The double-sided tape 1027 must be suitable for providing an NMR amplitude signal.

[0204] Similar to the frame 1023, the sample holder 1020 has an opening 1028 of 40 mm × 40 mm. The depth of the opening in the sample holder 1028 is 400 μm. The sample holder has dimensions of 80 mm × 80 mm and a height of 1.4 mm (including the 400 μm depth). The sample holder 1020 is placed in the middle of the NMR MOUSE on the plane 1006 (above the radiofrequency coil 1012) to ensure that the sensitive NMR volume is within the 40 mm × 40 mm opening 1028 where the liquid will be applied. The frame 1023 is centered on top of the sample holder 1020 such that the top marker and the opening 1028 are aligned, and the top marker is placed on the sample 1022 such that the glass plate 1026 is in contact with the sample 1022. The top marker is used to define the dimensions of the sample by determining the surfaces of the sample holder 1020 and the sample 1022 in the 40 mm × 40 mm opening area 1028.

[0205] Collect the first 1-D dry profile maps with and without the sample 1022, with the top marker on the sample. The dry profile map is the NMR signal varying with depth, with a resolution of 50 μm. Ensure that the sample prepared on the instrument is aligned above the top of the radiofrequency coil 1012. Program the NMR-MOUSE to use the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence, which consists of a 90° x-pulse followed by a refocusing pulse of 180° y-pulse, using the following conditions:

[0206] Repetition time = 500 ms

[0207] Number of scans = 8

[0208] Number of echoes = 8

[0209] Resolution = 50 μm

[0210] Step size = -50 μm

[0211] Pulse length = 5 μs

[0212] Echo time = 90 μs

[0213] Echo shift = 1 μs

[0214] As described by the vendor, the Rx phase of the NMR signal is optimized during phase adjustment to maximize the real part of the NMR signal used for data processing. For our experiment, a value of 230° is applied. However, the optimal value may vary depending on the NMR instrument used, so the Rx phase should be optimized as described by the vendor. The pulse length of the 90° pulse depends on the depth measurement value here, which is 5 mm, and is determined to be 5 μs based on the optimization procedure described by the vendor. If necessary, a spacer 1011 can be used to adjust the depth (see Figure 3 ).

[0215] As the high-precision lifter steps through the depth of the sample, NMR amplitude data (in arbitrary units a.u.) is collected against depth (μm). Representative curves with a dry sample are shown in Figure 5B and representative curves without a sample are shown in Figure 5A .

[0216] After measuring the dry distribution map, the top marker and the frame 1023 to which the sample 1022 is attached are removed. 400 μl of the test solution (see above for the preparation of the test solution) is applied in the opening 1028 of the sample holder 1020. Then the frame 1023, to which the sample 1022 is still attached, is immediately placed on top of the sample holder 1020. One minute after the sample 1022 has been brought into contact with the test solution, the NMR 1-D wetting distribution map in the wet state of the sample is measured. This map is used to calculate the liquid ratio of the front 200 μm and the last 200 μm sub-thicknesses to the total thickness value after one minute.

[0217] The NMR 1-D wetting profile can also be used to calculate the liquid ratio of the front 200-μm sub-thickness to the second total thickness after 10 minutes and 20 minutes. The profile is determined as follows: The evaporation step is carried out without additional air ventilation, i.e., evaporation is not accelerated by air ventilation. During the entire evaporation time, the frame with the sample is held on top of the sample holder. After 10 minutes of evaporation time (without further waiting), the NMR 1-D wetting profile is measured. The profile is used to calculate the liquid ratio of the front 200-μm and the last 200-μm sub-thicknesses to the total thickness value after ten minutes. The “front 200 μm” is the sub-thickness facing the bottom of the sample holder, and the “last 200 μm” is the sub-thickness facing away from the sample holder. The front 200 μm includes the first outward-facing surface of the sample. If the sample is taken from an elastic laminate forming an elastic band of a wearable article, the first outward-facing surface contacts the skin of the wearer when the article is applied to the wearer. The last 200 μm includes the second outward-facing surface of the sample (which is opposite to the first outward-facing surface). If the sample is taken from an elastic laminate forming an elastic band of a wearable article, the second outward-facing surface is the surface facing the clothing when the article is applied to the wearer and does not directly contact the skin of the wearer.

[0218] Repeat the process to allow the liquid to evaporate through the sample 1022 for another 10 minutes (like the previous 10 minutes, this evaporation step is carried out without additional air ventilation, i.e., evaporation is not accelerated by air ventilation). Measure the NMR 1-D wetting profile in the wetting state of the sample after 20 minutes of evaporation. The profile is used to calculate the liquid ratio of the front 200-μm and the last 200-μm sub-thicknesses to the second total thickness value after twenty minutes.

[0219] When starting the evaporation time, after obtaining the dry profile, the test solution is not filled into the opening 1028 anymore, i.e., the test solution is filled only once.

[0220] Figures 6A to 6D Show the dry profile and the wetting profiles after 1 minute, 10 minutes, and 20 minutes.

[0221] Calculate the liquid ratio of the front 200-μm and the last 200-μm thicknesses to the total thickness as described below. Figure 5C Show a typical example of the liquid distribution according to the depth change.

[0222] For any range of thicknesses of interest, such as the total thickness in the sample (i.e., the total thickness of the elastic laminate), the front and last 200-μm sub-thicknesses of the sample (i.e., the front 200-μm sub-thickness of the elastic laminate), and the total thickness of the sample (i.e., the total thickness of the elastic laminate), perform area calculations:

[0223]

[0224] where X i is the depth in μm corresponding to the data point, S i is the amplitude of the corresponding NMR signal, and n is the total number of data points.

[0225] Determine the liquid ratio of the front 200 μm to the total thickness of the sample product.

[0226]

[0227] Similarly, the percentage of the liquid volume in the last 200 μm of the sample to the liquid volume in the total thickness is calculated as follows:

[0228]

[0229] where the liquid ratio [%] is the ratio of the remaining liquid in the front 200 μm or the last 200 μm of the sample to the total thickness of the sample, as Figure 5C shown. The total thickness of the flattened elastic laminate is determined by using the position of the top marker on the top of the sample holder without any sample (shown in Figure 5A ) and the position of the top marker outside the 1D drying profile (see Figure 5B ), where the total thickness of the elastic laminate is the "thickness of the sample".

[0230] Each measurement (drying profile 1 minute later, wetting profile) is performed on only one sample. Corresponding to each wetting profile measurement,

[0231] calculate the % liquid ratio [%] in the front 200 microns / total thickness and the % liquid ratio [%] in the last 200 microns / total thickness, and report to the nearest tenth of a percent.

[0232] Relative opening ratio

[0233] The relative opening ratio is the opening ratio of the combined outer and inner fiber webs compared to the opening ratio of the outer fiber web. Before preparing the sample, observe the relationship of the openings from the outer and inner fiber webs as the elastic laminate. If the inner fiber web has no openings, the relative opening ratio is determined to be 0%. If the inner fiber web has openings and the openings from the outer and inner fiber webs appear to match completely or substantially, the sample is arranged according to A). If the inner fiber web has openings and the openings from the outer and inner fiber webs appear to partially match or not match, the sample is arranged according to B).

[0234] A) Process the elastic laminate according to the preparation of the above sample to obtain an internal fiber web and an external fiber web. Overlap the internal fiber web and the external fiber web such that the openings match each other as much as possible. Deliver the overlapped sample for measurement.

[0235] B) Process the elastic laminate according to the preparation of the above sample to obtain an internal fiber web and an external fiber web. Overlap the internal fiber web and the external fiber web at two different degrees of overlap of the openings, one with the openings matching as much as possible and the other with the openings not matching as much as possible. Deliver the two types of overlapped samples separately for measurement. Obtain the average relative opening ratio of the two types of overlapped samples.

[0236] Measure the overlapped sample in the same manner as specified according to "2. Effective opening area and opening ratio" to obtain the opening ratio of the overlapped sample.

[0237] Obtain the relative opening ratio in this way. When there is a perfect match between the internal fiber web and the external fiber web, the relative opening ratio is 100%.

[0238] Relative opening ratio (%) = Opening ratio of the overlapped sample / Opening ratio of the external fiber web × 100

[0239] Average flow pore size

[0240] The average flow pore size of the nonwoven material is characterized by the gas-liquid displacement method according to ASTM F316, using a capillary flow porosimeter such as Porolux TM 100NW (Porometer N.V., Belgium). Pore measurements follow the Young-Laplace formula, P = 4 * γ * cos(θ) / D, where D is the pore diameter, P is the measured pressure, γ is the surface tension of the wetting liquid, and θ is the contact angle of the wetting liquid with the sample. The procedure is as follows:

[0241] 1) Wet the sample with a liquid having a low surface tension and a low vapor pressure (e.g., the commercial wetting liquid Porefil (Prorometer N.V., Belgium) with a surface tension of 16 mN / m). Thus, all pores are filled with the liquid.

[0242] 2) An inert gas is used to displace the wetting liquid from the pores, and a flowmeter is usually used to measure the gas flow rate. The liquid is blown out of the sample by gradually increasing the gas pressure. When the pressure is further increased, the gas flows through the small pores until all pores are emptied. Record the gas pressure and gas flow rate when the liquid is discharged.

[0243] 3) After the wet run, measure the same sample in the dry state.

[0244] 4) The pore size parameters are calculated according to ASTM F316 by comparing the pressure-flow curves from wet runs and dry runs.

[0245] Examples

[0246] The following examples and comparative examples were tested:

[0247] Comparative Example 1 :

[0248] Inner fiber web = First fiber web: spunbond nonwoven material (SSS, i.e., three identical spunbond layers); 100% polypropylene; fiber diameter of about 15 μm; basis weight of 15 gsm. This nonwoven material is provided by Fibertex under the trade name A10150AH.

[0249] Outer fiber web = Second fiber web: carded air-laid bonded nonwoven material, bicomponent PE / PET 50% PET (core of the bicomponent fiber), 50% polyethylene (sheath of the bicomponent fiber), fiber diameter of about 14.3 μm; basis weight of 20 gsm. This nonwoven material is provided by Dayuan under the trade name FJ206.

[0250] Comparative Example 2 :

[0251] Inner fiber web = First fiber web: the same as the inner fiber web of Comparative Example 1

[0252] Outer fiber web = Second fiber web: carded air-laid bonded nonwoven material, bicomponent PE / PET 50% PET, 50% polyethylene, fiber diameter of about 14.8 μm; basis weight of 22 gsm. This nonwoven material is provided by Yanjan under the trade name Z05X-22.

[0253] Example 1 :

[0254] Inner fiber web = Second fiber web: spunlace nonwoven material, total basis weight 25 gsm; the first fiber layer is a spunbond nonwoven material (SSS), PP, fiber diameter of about 15.1 μm and basis weight of 11 gsm; the second fiber layer is cotton fiber with a basis weight of 14 gsm (the second fiber layer faces the outer fiber web). The first fiber layer and the second fiber layer are bonded by spraying liquid in the spunlace process so that at least some fibers of the second fiber layer penetrate the fibers of the first fiber layer. This nonwoven material is provided by Yanjan under the trade name FL08-25.

[0255] Outer fiber web = First fiber web: the same as the outer fiber web of Comparative Example 2

[0256] Example 2 :

[0257] Inner fiber web = second fiber web: the same as the inner fiber web of Example 1

[0258] Outer fiber web = first fiber web: spunbond nonwoven material (SSS, i.e., three identical spunbond layers); 100% polypropylene; fiber diameter of approximately 16.2 μm; basis weight of 15 gsm. This nonwoven material is provided by Fibertex under the trade name A20150KV.

[0259] Example 3 :

[0260] Inner fiber web = first fiber web: the same as the outer fiber web of Example 2

[0261] Outer fiber web = second fiber web: the same as the inner fiber web of Example 1, but the second fiber layer faces the inner fiber web.

[0262] Example 4 :

[0263] Inner fiber web = second fiber web: hydroentangled nonwoven material, total basis weight 30 gsm; the first fiber layer is a spunbond nonwoven material (SSS), PP, fiber diameter of approximately 15.1 μm and basis weight of 11 gsm; the second fiber layer is cotton fiber with a basis weight of 19 gsm (the second fiber layer faces the outer fiber web). The first fiber layer and the second fiber layer are bonded by spraying liquid in the hydroentangling process, such that at least some fibers of the second fiber layer penetrate through the fibers of the first fiber layer. This nonwoven material is provided by Yanjan under the trade name FL08 - 30.

[0264] Outer fiber web = first fiber web: the same as the outer fiber web of Comparative Example 2

[0265] Example 5 :

[0266] Inner fiber web = first fiber web: the same as the outer fiber web of Example 2

[0267] Outer fiber web = second fiber web: the same as the inner fiber web of Example 4, but the second fiber layer faces the inner fiber web.

[0268] Table 1: Characterization of the inner fiber web and the outer fiber web (average surface area / volume, contact angle)

[0269]

[0270] Table 2: Characterization of the inner fiber web and the outer fiber web; cosine of the contact angle θ multiplied by the average surface area per volume

[0271]

[0272]

[0273] For the NMR MOUSE test, a sample is formed to simulate the condition of folding an extension of an outer web onto an inner web such that the sample tested according to the NMR MOUSE test method has three layers, namely an inner web sandwiched between two outer webs (i.e., the outer web and the extension of the outer web). The sample is formed without elastic strands therebetween, and the inner web and the outer webs are attached to each other with a 5 gsm adhesive in a spiral pattern. The test result refers to 1 minute after the sample is contacted with the test solution.

[0274] Table 3: Test results of the NMR MOUSE test

[0275]

[0276] The foremost 200 microns is a sub-thickness starting from the downward-facing surface towards the bottom of the sample holder. The last 200 microns is a sub-thickness starting from the upward-facing surface. If the elastic laminate is used as an elastic band, the foremost 200 microns starts from the skin-facing surface of the elastic band, extends through the thickness of the elastic laminate (= thickness) towards the clothing-facing surface of the elastic laminate, and the last 200 microns will start from the clothing-facing surface of the elastic laminate, extend through the thickness of the elastic laminate (= thickness) towards the skin-facing surface of the elastic laminate.

[0277] Seven adults (hereinafter referred to as panelists) were tested for wear during use using a wearable article in the form of an adult incontinence pant. The panelists were required not to shower or bathe and not to exercise for two hours before the start of the test, so the skin was dry at the start of the test. In addition, the panelists were advised not to use any creams, lotions, and cosmetics on their skin 24 hours before the start of the test. Each of the seven panelists tested one sample of Comparative Examples 1 and 2 and Examples 4 and 6. The panelists were tested in a random sample order (circular scheduling).

[0278] The elastic bands of the pants of the comparative examples and examples were formed of an elastic laminate. The outer web of the elastic band includes an extension that extends beyond the front waist edge and the rear waist edge, and the extension is folded onto the inner web such that the fold forms the front waist edge and the rear waist edge, and a portion of the elastic band includes an inner web ( = 3-layer region) sandwiched between the outer web and the extension of the outer web. The extension extends approximately 10 mm and 40 mm from the front waist edge and the rear waist edge towards the crotch region, respectively.

[0279] After a 15-minute acclimation period in the CTCH chamber (29°C ± 1°C and 50% ± 5% RH) (CTCH = Controlled Temperature, Controlled Humidity), the panelists walked on a motorized treadmill at a speed between 3.5 Km / h - 4.5 Km / h for 15 minutes in the CTCH chamber (29°C ± 1°C and 50% ± 5% RH). At the end of the treadmill walking phase, EWL (= Evaporative Water Loss) was measured directly on the skin area of the panelists in contact with the 3-layer area after removing the strap on the back using a Delfin Vapometer SWL-2 manufactured by Delfin Technologies, Finland. The vapometer is an independent device with a predefined time (10 seconds) and algorithm calculation. We can refer to the user manual in the protocol.

[0280] The average EWL is reported in Table 3. A lower EWL indicates that the elastic laminate performs better in transporting sweat away from the skin.

[0281] Table 4: Average EWL

[0282]

[0283] Based on NMR tests conducted on 3-layer samples (i.e., two outer fiber webs with an inner fiber web in between), Examples 2 and 3 showed a decrease in the % of liquid in the front 200 microns / total thickness on the skin-facing side compared to the Comparative Examples, while the % of liquid in the last 200 microns / total thickness on the outer side was comparable for Examples 2 and 3 relative to the Comparative Examples. This is consistent with the data of the average EWL of Examples 4 and 5, reflecting a decrease in skin hydration.

[0284] The dimensions and values disclosed herein should not be construed as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to represent that value and the range functionally equivalent around that value. For example, a dimension disclosed as "40 mm" is intended to represent "about 40 mm". In addition, each numerical range given throughout this specification includes every narrower numerical range that falls within such broader numerical ranges.

[0285] Unless expressly excluded or otherwise limited, each document cited herein, including any cross-referenced or related patent or application, is hereby incorporated by reference in its entirety. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone or in any combination with any one or more other references anticipates, suggests, or discloses any such invention. Further, when any meaning or definition of a term in this invention conflicts with the same term's meaning or definition in a document incorporated by reference, the meaning or definition assigned to the term in this invention shall govern.

[0286] While specific embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the present invention. Accordingly, it is intended that all such changes and modifications that fall within the scope of the present invention be covered by the appended claims.

Claims

1. A wearable article comprising an elastic laminate, said elastic laminate comprising a first fibrous web and a second fibrous web in a face-to-face relationship, wherein each of said first fibrous web and said second fibrous web constitutes the entire surface area of the elastic laminate, wherein said first fibrous web is a nonwoven fibrous web, and wherein said second fibrous web is formed by a first fibrous layer and a second fibrous layer, a) wherein said second fibrous layer is more hydrophilic than said first fibrous layer, and the second fibrous layer of the second fibrous web has a higher capillary pressure than the first fibrous web ； and / or b) said second fibrous layer has a higher average surface area per volume than said first fibrous layer, wherein each of said first fibrous layer and said second fibrous layer has a contact angle θ, and wherein said first fibrous web has a contact angle θ, and wherein the cosine of said contact angle θ multiplied by the average surface area per volume of said second fibrous layer is greater than the cosine of said contact angle θ multiplied by the average surface area per volume of said first fibrous web, and wherein the cosine of said contact angle θ multiplied by the average surface area per volume of said second fibrous layer is higher than the cosine of said contact angle θ multiplied by the average surface area per volume of said first fibrous layer; wherein said first fibrous layer and said second fibrous layer are integrally joined to each other, and wherein at least some of the fibers of said second fibrous layer interpenetrate the fibers of said first fibrous layer, said first fibrous layer forming the first surface of the second fibrous web, and said second fibrous layer forming the second surface of the second fibrous web, wherein said second surface faces said first fibrous web, and said first surface faces away from said first fibrous web.

2. The wearable article according to claim 1, wherein at least some of the fibers of said second fibrous layer interpenetrate the fibers of said first fibrous layer such that they protrude from the first surface of the second fibrous web.

3. The wearable article according to claim 1 or 2, wherein said first fibrous web forms the internal fibrous web of the elastic laminate such that at least a portion of said first fibrous web is in direct contact with the skin of the wearer, and said second fibrous web forms the external fibrous web of the elastic laminate.

4. The wearable article according to claim 1 or 2, wherein said second fibrous web forms the internal fibrous web of the elastic laminate such that at least a portion of the first surface of said second fibrous web is in direct contact with the skin of the wearer when the article is in use, and said first fibrous web forms the external fibrous web of the elastic laminate.

5. The wearable article according to claim 1 or 2, wherein said second fibrous layer is a carded layer, and the fibers of said second fibrous layer are staple fibers.

6. The wearable article according to claim 1 or 2, wherein said first fibrous layer is a spunbond layer formed of continuous fibers, or said first fibrous layer is a carded layer formed of staple fibers.

7. The wearable article according to claim 1 or 2, wherein the first fiber layer is a carded breathable bonded layer formed of staple fibers, and wherein the staple fibers are bicomponent fibers.

8. The wearable article according to claim 1 or 2, wherein the first fiber layer and the second fiber layer are integrally bonded by a hydroentangling method.

9. The wearable article according to claim 1 or 2, wherein the fibers of the second fiber layer are not consolidated before being integrally bonded to the fibers of the first fiber layer.

10. The wearable article according to claim 1 or 2, wherein no adhesive and / or no binder is used to bond the first fiber layer and the second fiber layer.

11. The wearable article according to claim 1 or 2, wherein at least 40% or at least 50% of the surface area of the elastic laminate, as measured when the elastic laminate is stretched such that the first fiber web and the second fiber web are flattened, does not include any additional layer other than the first fiber web and the second fiber web.

12. The wearable article according to claim 1 or 2, wherein the second fiber layer comprises natural hydrophilic fibers and / or modified hydrophilic fibers.

13. The wearable article according to claim 12, wherein the amount of natural hydrophilic fibers and / or artificially modified hydrophilic fibers gradually increases from the first surface of the second fiber web towards the second surface through the thickness of the second fiber web.

14. The wearable article according to claim 12, wherein the natural hydrophilic fibers or modified natural hydrophilic fibers are selected from the group consisting of cotton, bamboo, viscose fiber, cellulose, silk, or a mixture or combination thereof.

15. The wearable article according to claim 1 or 2, wherein, in the second fiber web, the basis weight ratio of the first fiber layer to the second fiber layer is from 0.2 to 3, or from 0.2 to 2.5, or from 0.5 to 1.5, or from 0.5 to 1.

16. The wearable article according to claim 1 or 2, wherein based on the total basis weight of the first fiber web, the first fiber web comprises at least 70% by weight of synthetic fibers, and wherein the synthetic fibers of the first fiber web are selected from the group consisting of polyethylene, polypropylene, polyester, polylactic acid (PLA), and combinations thereof, and wherein the first fiber web does not include fiber layers integrally bonded to each other such that at least some of the fibers of the second fiber layer interpenetrate the fibers of the first fiber layer.

17. The wearable article according to claim 1 or 2, wherein the surface area of the elastic laminate does not include any additional material layer other than the first fiber web and the second fiber web.

18. The wearable article according to claim 1 or 2, wherein a plurality of elastic strands are provided between the first fiber web and the second fiber web.

19. The wearable article according to claim 1 or 2, wherein the second fiber web is water-permeable.

20. The wearable article according to claim 1 or 2, wherein the wearable article comprises a central base structure and an annular elastic band formed from the elastic laminate and consisting of a front band and a rear band; a center of the front band is joined to a front waist panel of the central base structure, a center of the rear band is joined to a rear waist panel of the central base structure, and the remainder of the central base structure forms a crotch region, each of the front band and the rear band having a left side panel and a right side panel where the central base structure does not overlap, and transverse edges of the front band and the rear band are joined by seams to form a waist opening defined by a front waist edge and a rear waist edge and also to form two leg openings; wherein the front band and the rear band are longitudinally discontinuous with each other in the crotch region; and wherein the second fibrous web forms an outer fibrous web of the front band and the rear band, and the first fibrous web forms an inner fibrous web of the front band and the rear band, the outer fibrous web including an extension portion that extends beyond the front waist edge and the rear waist edge, and the extension portion is folded over the inner fibrous web such that the fold forms the front waist edge and the rear waist edge, and at least a portion of the elastic band includes the inner fibrous web sandwiched between the outer fibrous web and the extension portion of the outer fibrous web.

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