具体实施方式：
[0045]Unless otherwise defined, all terms used in disclosing characteristics of the disclosure, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present disclosure.
[0046]As used herein, the following terms have the following meanings:
[0047]“A”, “an”, and “the” as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, “a compartment” refers to one or more than one compartment.
[0048]“About” as used herein referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/−20% or less, preferably +/−10% or less, more preferably +/−5% or less, even more preferably +/−1% or less, and still more preferably +/−0.1% or less of and from the specified value, in so far such variations are appropriate to perform in the disclosed disclosure. However, it is to be understood that the value to which the modifier “about” refers is itself also specifically disclosed.
[0049]“Comprise”, “comprising”, and “comprises” and “comprised of” as used herein are synonymous with “include”, “including”, “includes” or “contain”, “containing”, “contains” and are inclusive or open-ended terms that specifies the presence of what follows e.g. component and do not exclude or preclude the presence of additional, non-recited components, features, element, members, steps, known in the art or disclosed therein.
[0050]The expression “% by weight” (weight percent), here and throughout the description unless otherwise defined, refers to the relative weight of the respective component based on the overall weight of the formulation.
[0051]The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within that range, as well as the recited endpoints.
[0052]“Absorbent article” refers to devices that absorb and contain liquid, and more specifically, refers to devices that are placed against or in proximity to the body of the wearer to absorb and contain the various exudates discharged from the body. Absorbent articles include but are not limited to diapers, adult incontinence briefs, training pants, diaper holders and liners, sanitary napkins and the like, as well as surgical bandages and sponges. Absorbent articles preferably comprise a longitudinal axis and a transversal axis perpendicular to said longitudinal axis. The longitudinal axis is hereby conventionally chosen in the front-to-back direction of the article when referring to the article being worn, and the transversal axis is conventionally chosen in the left-to-right direction of the article when referring to the article being worn. Disposable absorbent articles can include a liquid pervious top sheet, a back sheet joined to the top sheet, and an absorbent core positioned and held between the top sheet and the back sheet. The top sheet is operatively permeable to the liquids that are intended to be held or stored by the absorbent article, and the back sheet may or may not be substantially impervious or otherwise operatively impermeable to the intended liquids. The absorbent article may also include other components, such as liquid wicking layers, liquid intake layers, liquid distribution layers, transfer layers, barrier layers, wrapping layers and the like, as well as combinations thereof. Disposable absorbent articles and the components thereof can operate to provide a body-facing surface and a garment-facing surface.
[0053]An absorbent article, such as a diaper, comprises a front waistband region, a back waistband region, an intermediate crotch region which interconnects the front and rear waistband regions. When used herein, reference to a “front” portion refers to that part of the absorbent article which is generally located on the front of a subject, such as an infant or adult, when in use. Reference to the “rear” portion refers to the portion of the absorbent article generally located at the rear of the subject, such as an infant or adult, when in use, and reference to the “crotch” portion refers to that portion which is generally located between the legs of subject, such as an infant or adult, when in use. The crotch region is an area where repeated fluid surge typically occurs, within the absorbent article assembly.
[0054]“Front”, “rear or back”, and “crotch” portions of the absorbent core as used herein typically refer to portions of the absorbent core that are proximal to respective portions of the absorbent article. For example, the “front” portion of the core is that which is most proximal to the front of the subject when worn, the “rear or back” portion of the core is that which is most proximal to the rear or back of the subject when worn, and the “crotch” portion of the core is the middle portion of the absorbent core between the “front” and “rear or back” portions.
[0055]Preferably, a diaper comprises a liquid permeable “top sheet”, a liquid impermeable “back sheet”, and an “absorbent medium” disposed between the top sheet and the back sheet. The top sheet, back sheet and the absorbent medium could be made from any suitable material known to the person skilled in the art. The top sheet is generally located at or near the bodyside surface of the article, while the back sheet is generally located at or near the garment-side surface of the article. Optionally, the article may comprise one or more separate layers which are in addition to the back sheet and are interposed between the back sheet and the absorbent medium. Top sheet and back sheet are connected or otherwise associated together in an operable manner.
[0056]The “absorbent medium” or “absorbent core” or “absorbent body” is the absorbent structure disposed between the top sheet and the back sheet of the absorbent article in at least the crotch region of the absorbent article and is capable of absorbing and retaining liquid body exudates. The size and the absorbent capacity of the absorbent medium should be compatible with the size of the intended wearer and the liquid loading imparted by the intended use of the absorbent article. Further, the size and the absorbent capacity of the absorbent medium can be varied to accommodate wearers ranging from infants through adults. It may be manufactured in a wide variety of shapes (for example, rectangular, trapezoidal, T-shape, I-shape, hourglass shape, etc.) and from a wide variety of materials. Examples of commonly occurring absorbent materials are cellulosic fluff pulp, tissue layers, highly absorbent polymers (so called superabsorbent polymer particles (SAP)), absorbent foam materials, absorbent nonwoven materials or the like. It is common to combine cellulosic fluff pulp with superabsorbent polymers in an absorbent material.
[0057]“Acquisition and distribution layer”, “ADL” or “surge management portion” refers to a sub-layer which preferably is a nonwoven wicking layer under the top sheet of an absorbent product, which speeds up the transport and improves distribution of fluids throughout the absorbent core. The surge management portion is typically less hydrophilic than the retention portion, and has the ability to quickly collect and temporarily hold liquid surges, and to transport the liquid from its initial entrance point to other parts of the absorbent structure, particularly the retention portion. This configuration can help prevent the liquid from pooling and collecting on the portion of the absorbent garment positioned against the wearer's skin, thereby reducing the feeling of wetness by the wearer. Preferably, the surge management portion is positioned between the top sheet and the retention portion.
[0058]The term “adhesive” as used herein is intended to refer to any suitable hot melt, water or solvent borne adhesive that can be applied to a surface of a film layer in the required pattern or network of adhesive areas to form the film-nonwoven laminate of the present disclosure. Accordingly, suitable adhesives include conventional hot melt adhesives, pressure-sensitive adhesives and reactive adhesives (i.e., polyurethane).
[0059]As used herein, the term “adhesive bonding” means a bonding process which forms a bond by application of an adhesive. Such application of adhesive may be by various processes such as slot coating, spray coating and other topical applications. Further, such adhesive may be applied within a product component and then exposed to pressure such that contact of a second product component with the adhesive containing product component forms an adhesive bond between the two components.
[0060]As used herein, an “airformed web” refers to a material comprising cellulosic fibers such as those from fluff pulp that have been separated, such as by a hammermilling process, and then deposited on a porous surface without a substantial quantity of binder fibers present. Airfelt materials used as the absorbent core in many diapers, for example, are a typical example of an airformed material.
[0061]As used herein, an “airlaid web” is a fibrous structure formed primarily by a process involving deposition of air-entrained fibers onto a mat, typically with binder fibers present, and typically followed by densification and thermal bonding. In addition to traditional thermally bonded airlaid structures (those formed with non-tacky binder material present and substantial thermally bonded), the scope of the term “airlaid” according to the present disclosure can also include coform, which is produced by combining air-entrained dry, dispersed cellulosic fibers with meltblown synthetic polymer fibers while the polymer fibers are still tacky. Further, an airformed web to which binder material is subsequently added can be considered within the scope of the term “airlaid” according to the present disclosure. Binder can be added to an airformed web in liquid form (e. g., an aqueous solution or a melt) by spray nozzles, direction injection or impregnation, vacuum drawing, foam impregnation, and so forth. Solid binder particles can also be added by mechanical or pneumatic means.
[0062]As used therein, the term “associated” encompasses configurations in which top sheet is directly joined to back sheet by affixing top sheet directly to back sheet, and configurations wherein top sheet is joined to back sheet by affixing top sheet to intermediate members which in turn are affixed to back sheet. Top sheet and back sheet can be affixed directly to each other by attachment means such as an adhesive, sonic bonds, thermal bonds or any other attachment means known in the art. For example, a uniform continuous layer of adhesive, a patterned layer of adhesive, a sprayed pattern of adhesive or an array of separate lines, swirls or spots of construction adhesive may be used to affix top sheet to back sheet. It should be readily appreciated that the above-described attachment means may also be employed to interconnect and assemble together the various other component parts of the article described herein.
[0063]The terms “back section” and “rear back section” are used herein as synonyms and refer to the area of the absorbent article which is contact with the back of the wearer when the absorbent article is worn.
[0064]The term “back sheet” refers to a material forming the outer cover of the absorbent article. The back sheet prevents the exudates contained in the absorbent structure from wetting articles such as bedsheets and overgarments which contact the disposable absorbent article. The back sheet may be a unitary layer of material or may be a composite layer composed of multiple components assembled side-by-side or laminated. The back sheet may be the same or different in different parts of the absorbent article. At least in the area of the absorbent medium the back sheet comprises a liquid impervious material in the form of a thin plastic film, e.g. a polyethylene or polypropylene film, a nonwoven material coated with a liquid impervious material, a hydrophobic nonwoven material, which resists liquid penetration, or a laminate of a plastic film and a nonwoven material. The back sheet material may be breathable so as to allow vapour to escape from the absorbent material, while still preventing liquids from passing there through. Examples of breathable back sheet materials are porous polymeric films, nonwoven laminates of spunbond and meltblown layers and laminates of porous polymeric films and nonwoven materials.
[0065]The terms “belly section” and “front belly section” are used herein as synonyms and refer to the area of the absorbent article which is contact with the belly of the wearer when the absorbent article is worn.
[0066]The term “blend” means a mixture of two or more polymers while the term “alloy” means a sub-class of blends wherein the components are immiscible but have been compatibilized.
[0067]As used herein, the “skin-facing”, “body-facing” or “bodyside” surface means that surface of the article or component which is intended to be disposed toward or placed adjacent to the body of the wearer during ordinary use, while the “outward”, “outward-facing” or “garment-side” surface is on the opposite side, and is intended to be disposed to face away from the wearer's body during ordinary use. Such outward surface may be arranged to face toward or placed adjacent to the wearer's undergarments when the absorbent article is worn.
[0068]“Bonded” refers to the joining, adhering, connecting, attaching, or the like, of at least two elements. Two elements will be considered to be bonded together when they are bonded directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements.
[0069]The term “breathable” refers to films having a water vapor transmission rate (WVTR) of at least 300 grams/m2-24 hours.
[0070]“Carded web” refers to webs that are made from staple fibers that are sent through a combing or carding unit, which opens and aligns the staple fibers in the machine direction to form a generally machine direction-oriented fibrous nonwoven web. The web is then bonded by one or more of several known bonding methods. Bonding of nonwoven webs may be achieved by a number of methods; powder bonding, wherein a powdered adhesive or a binder is distributed through the web and then activated, usually by heating the web and adhesive with hot air; pattern bonding, wherein heated calendar rolls or ultrasonic bonding equipment are used to bond the fibers together, usually in a localized bond pattern, though the web can be bonded across its entire surface if so desired; through-air bonding, wherein air which is sufficiently hot to soften at least one component of the web is directed through the web; chemical bonding using, for example, latex adhesives that are deposited onto the web by, for example, spraying; and consolidation by mechanical methods such as needling and hydroentanglement.
[0071]As used herein, the term “cellulosic” is meant to include any material having cellulose as a major constituent, and specifically comprising at least 50 percent by weight cellulose or a cellulose derivative. Thus, the term includes cotton, typical wood pulps, nonwoody cellulosic fibers, cellulose acetate, cellulose triacetate, rayon, thermomechanical wood pulp, chemical wood pulp, debonded chemical wood pulp, milkweed, or bacterial cellulose.
[0072]“Chassis” refers to a foundational constituent of an absorbent article upon which the remainder of the structure of the article is built up or overlaid, e.g., in a diaper, the structural elements that give the diaper the form of briefs or pants when configured for wearing, such as a back sheet, a top sheet, or a combination of a top sheet and a back sheet.
[0073]“Coform” as used herein is intended to describe a blend of meltblown fibers and cellulose fibers that is formed by air forming a meltblown polymer material while simultaneously blowing air-suspended cellulose fibers into the stream of meltblown fibers. The coform material may also include other materials, such as superabsorbent particles. The meltblown fibers containing wood fibers are collected on a forming surface, such as provided by a foraminous belt. The forming surface may include a gas-pervious material, such as spunbonded fabric material, that has been placed onto the forming surface.
[0074]“Compression” refers to the process or result of pressing by applying force on an object, thereby increasing the density of the object.
[0075]The term “consisting essentially of” does not exclude the presence of additional materials which do not significantly affect the desired characteristics of a given composition or product. Exemplary materials of this sort would include, without limitation, pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, solvents, particulates and materials added to enhance processability of the composition.
[0076]The diaper can comprise “containment flaps” or “barrier cuffs”. The containment flaps are generally thought to be particularly well suited for the containment of fecal matter and to prevent the lateral flow of liquid waste until such time as the liquid waste can be absorbed by the absorbent article. Many constructions of containment flaps are known. Such containment flaps generally comprise a proximal edge, intended to be attached to the absorbent article, and an opposite distal edge which is generally not attached to the absorbent article along at least a portion of its length. An elastic member is generally located adjacent the distal edge to assist in maintaining the containment flap in an upright condition and in maintaining a sealing relationship between the distal edge of the containment flap and the body of a wearer during use. The elastic member is generally located between two layers of material so that the elastic does not come into contact with the body of a wearer. The containment flaps may be manufactured from a wide variety of materials such as polypropylene, polyester, rayon, nylon, foams, plastic films, formed films, and elastic foams. A number of manufacturing techniques may be used to manufacture the containment flaps. For example, the containment flaps may be woven, non-woven, spunbonded, carded, cast, blown or the like.
[0077]The diaper can comprise leg containment gaskets. Leg “containment gaskets” help prevent leakage of bodily exudates when the wearer exerts compressive forces on the absorbent article. In particular, the stiffness of the leg containment gaskets prevents twisting and bunching of the leg openings of the absorbent article which can lead to leaks. In addition, the elasticity and conformability of the leg containment gaskets ensures that the bodyfacing surface of the leg containment gaskets provides an adequate seal against the body of the wearer. The physical properties of the leg containment gaskets, such as the thickness and stiffness, also function to space the bodyside liner, outer cover and absorbent core away from the wearer's body when in use. As such, void volume is created between the wearer's body and the bodyside liner and absorbent core of the absorbent article to help contain body exudates.
[0078]A “continuous waistband” can be an elastomeric, cloth-like, nonwoven fibrous material, such as an elastomeric stretch bonded laminate web or an elastomeric meltblown web. By proper selection of materials, the continuous waistband can be rendered temporarily elastically inhibited, such as by compression. Once temporarily elastically inhibited, the elastic material, of which waistband is comprised, can be activated, such as by treating with heat, to recover to a state of elasticity.
[0079]“Conventional hot-melt adhesive” means a formulation that generally comprises several components. These components typically include one or more polymers to provide cohesive strength (e.g., aliphatic polyolefins such as poly (ethylene-co-propylene) copolymer; ethylene vinyl acetate copolymers; styrene-butadiene or styrene-isoprene block copolymers; etc.); a resin or analogous material (sometimes called a tackifier) to provide adhesive strength (e.g., hydrocarbons distilled from petroleum distillates; rosins and/or rosin esters; terpenes derived, for example, from wood or citrus, etc.); perhaps waxes, plasticizers or other materials to modify viscosity (i.e., flowability) (examples of such materials include, but are not limited to, mineral oil, polybutene, paraffin oils, ester oils, and the like); and/or other additives including, but not limited to, antioxidants or other stabilizers. A typical hot-melt adhesive formulation might contain from about 15 to about 35 weight percent cohesive strength polymer or polymers; from about 50 to about 65 weight percent resin or other tackifier or tackifiers; from more than zero to about 30 weight percent plasticizer or other viscosity modifier; and optionally less than about 1 weight percent stabilizer or other additive. It should be understood that other adhesive formulations comprising different weight percentages of these components are possible.
[0080]The term “density” or “concentration” when referring to the absorbent material, in particular the SAP, of a layer, refers to the amount of the absorbent material divided by the surface area of the layer over which the absorbent material is spread out.
[0081]As used herein, the term “diaper” refers to an absorbent article generally worn by infants about the lower torso.
[0082]The term “disposable” is used herein to describe absorbent articles that generally are not intended to be laundered or otherwise restored or reused as an absorbent article (i.e., they are intended to be discarded after a single use and, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner).
[0083]As used herein, the term “elastic resistance” describes an elastic force that tends to resist an applied tensile force causing a material provided therewith to tend to contract to an untensioned configuration in response to a stretching force.
[0084]As used herein, the terms “elastic”, “elastomeric”, “elasticity” or derivations thereof are used to describe the ability of various materials and objects comprised of such to reversibly undergo deformation under stress, e.g., become stretched or extended, in at least one direction when a force is applied to the material and to resume substantially to their original dimensions upon relaxing, i.e., when the force is released, without rupture or breakage. Preferably, it refers to a material or composite which can be elongated in at least one direction by at least 50% of its relaxed length, i.e., elongated to at least 150% of its relaxed length, and which will recover upon release of the applied tension at least 40% of its elongation. Accordingly, upon release of the applied tension at 50% elongation, the material or composite contracts to a relaxed length of not more than 130% of its original length. Examples of suitable elastomer materials include polyether-polyamide block copolymers, polyurethanes, synthetic linear A-B-A and A-B block copolymers, chlorinated rubber/EVA (ethylene-vinyl acetate) blends, EPDM (ethylene-propylene diene monomer) rubbers, EPM (ethylene-propylene monomer) rubbers, blends of EPDM/EPM/EVA, and the like.
[0085]The term “elasticized” refers to a material, layer, or substrate that is naturally non-elastic, but which has been rendered elastic by, for example, suitably joining an elastic material, layer, or substrate thereto.
[0086]“Elongation” means the ratio of the extension of a material to the length of the material prior to the extension (expressed in percent), as represented by the following: “Extension” means the change in length of a material due to stretching (expressed in units of length).
[0087]As used herein the term “extensible” means elongatable in at least one direction, but not necessarily recoverable.
[0088]The term “fabrics” is used to refer to all of the woven, knitted and nonwoven fibrous webs.
[0089]“Fastening means”, such as tape tab fasteners, are typically applied to the back waistband region of the diaper to provide a mechanism for holding the diaper on the wearer. Fastening means, such as tape tab fasteners, snaps, pins, belts, hooks, buckles, “hook/mushroom”-and-loop fasteners (e.g. VELCRO®-type fasteners) and the like, may be employed and are typically applied at the lateral, side ends of the back waistband region of diaper to provide a mechanism for holding the diaper about the waist of the wearer in a conventional manner. Tape tab fasteners can be any of those well known in the art, and are typically applied to the corners of the diaper. For example, adhesive fasteners, mechanical fasteners, hook-and-loop fasteners, snaps, pins or buckles, may be used alone, or in combination. For example, the fasteners can be adhesive fasteners, which are constructed to releasably adhere to a landing zone patch attached to the front waistband section of the diaper to provide a refastenable adhesive fastening system.
[0090]The term “finished” or “final”, when used with reference to a product, means that the product has been suitably manufactured for its intended purpose.
[0091]The term “flexible” refers to materials which are compliant and which will readily conform to the general shape and contours of the wearer's body.
[0092]As used herein, the term “garment” means any type of apparel which may be worn. This includes diapers, training pants, incontinence products, surgical gowns, industrial workwear and coveralls, undergarments, pants, shirts, jackets and the like.
[0093]Many of the known superabsorbent polymer particles exhibit gel blocking. “Gel blocking” occurs when superabsorbent polymer particles are wetted and the particles swell so as to inhibit fluid transmission to other regions of the absorbent structure. Wetting of these other regions of the absorbent member therefore takes place via a very slow diffusion process. In practical terms, this means acquisition of fluids by the absorbent structure is much slower than the rate at which fluids are discharged, especially in gush situations. Leakage from the absorbent article can take place well before the particles of SAP in the absorbent member are even close to being fully saturated or before the fluid can diffuse or wick past the “blocking” particles into the rest of the absorbent member. Gel blocking can be a particularly acute problem if the superabsorbent polymer particles do not have adequate gel strength and deform or spread under stress once the particles swell with absorbed fluid.
[0094]The term “graphic” includes, but is not limited to, any type of design, image, mark, figure, codes, words, patterns, or the like. For a product such as a training pant, graphics will generally include objects associated with little boys and little girls, such as multi-color trucks, airplanes, balls, dolls, bows, or the like.
[0095]“Hydroentanglement process” refers to the manufacturing of nonwoven webs. The process involves directing a series of water jets towards a fibrous web which is supported on a moving porous belt. The water jets pass downwards through the mass of fibres and on making contact with the surface of the belt, the jets rebound, and break up: the energy released causes entanglement of the mass of fibres.
[0096]The term “high-absorbency material” refers to materials that are capable of absorbing at least 10 times their own weight in liquid. The high-absorbency material may comprise absorbent gelling materials, such as superabsorbent polymers. Superabsorbent polymers are water-swellable, water-insoluble organic or inorganic materials capable of absorbing at least about 20 times their own weight of an aqueous solution containing 0.9 weight percent of sodium chloride. Absorbent gelling materials can be natural, synthetic and modified natural polymers and materials. In addition, the absorbent gelling materials can be inorganic materials, such as silica gels, or organic compounds such as cross-linked polymers. The term “cross-linked” refers to any means for effectively rendering normally water-soluble materials substantially water insoluble but swellable. Such means can include, for example, physical entanglement, crystalline domains, covalent bonds, ionic complexes and associations, hydrophilic associations, such as hydrogen bonding, and hydrophobic associations or Van der Waals forces. Examples of synthetic absorbent gelling material polymers include the alkali metal and ammonium salts of poly(acrylic acid) and poly (methacrylic acid), poly(acrylamides), poly(vinyl ethers), maleic anhydride copolymers with vinyl ethers and alpha-olefins, poly(vinyl pyrrolidone), poly(vinylmorpholinone), poly(vinyl alcohol), and mixtures and copolymers thereof. Further polymers suitable for use in the absorbent structure include natural and modified natural polymers, such as hydrolyzed acrylonitrile-grafted starch, acrylic acid grafted starch, methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, and the natural gums, such as alginates, xanthan gum, locust bean gum and the like. Mixtures of natural and wholly or partially synthetic absorbent polymers can also be used. Synthetic absorbent gelling materials typically are xerogels which form hydrogels when wetted. The term “hydrogel”, however, has commonly been used to also refer to both the wetted and unwetted forms of the material. The high-absorbency material may be in any of a wide variety of geometric forms. As a general rule, it is preferred that the high-absorbency material be in the form of discrete particles. However, the high-absorbency material may also be in the form of fibres, flakes, rods, spheres, needles, spiral or semi-spiral, cubic, rod-like, polyhedral, or the like. Conglomerates of particles of high-absorbency material may also be used. The high-absorbency material may be present in the absorbent core in an amount of from about 5 to about 100 weight percent and desirably from about 30 to about 100 weight percent based on the total weight of the absorbent core. The distribution of the high-absorbency material within the different portions of the absorbent core can vary depending upon the intended end use of the absorbent core. The high-absorbency material may be arranged in a generally discrete layer within the matrix of hydrophilic fibres. Alternatively, the absorbent core may comprise a laminate of fibrous webs and high-absorbency material or other suitable means of maintaining a high-absorbency material in a localized area.
[0097]A “hook-and-loop fastener” refers to complementary fastening means having a “hook” portion and a “loop” portion and which are refastenable. The term “hook” as used herein refers to any element capable of engaging another element, the so called “loop” portion. The term “hook” is not limited to only “hooks” in its normal sense, but rather encompasses any form of engaging elements, whether unidirectional or bi-directional. The term “loop” is likewise not limited to “loops” in its normal sense, but also encompasses any structure capable of engaging with a “hook” fastener. Examples of “loop” materials are fibrous structures, like nonwoven materials.
[0098]The term “hydrophilic” describes fibers or the surfaces of fibers which are wetted by the aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and materials involved. The term “wettable” is meant to refer to a fiber which exhibits a liquid, such as water, synthetic urine, or a 0.9 weight percent aqueous saline solution, in air contact angle of less than 90°, whereas “hydrophobic” or “non-wettable” describes fibers having contact angles equal to or greater than 90°.
[0099]As used herein, the term “impermeable” generally refers to articles and/or elements that are substantially not penetrated by aqueous fluid through the entire thickness thereof under a pressure of 1.0 kPa or less. Preferably, the impermeable article or element is not penetrated by aqueous fluid under pressures of 3.4 kPa or less. More preferably, the impermeable article or element is not penetrated