Nonwoven webs made from multi-component filaments and methods for forming nonwoven webs

Abstract

Nonwoven webs formed from fibers with two or more polymer-containing components and methods for producing such nonwoven webs are disclosed. The fibers contain a rapid crystallization additive capable of increasing the crystallization and / or solidification rate of the respective polymer-containing component. The use of the rapid crystallization additive in one of the polymeric components of the multicomponent filaments makes it possible to reduce or eliminate low-temperature polymers, which are generally required for softness, while maintaining the softness and strength of the nonwoven.

Description

BACKGROUND OF REVELATION

[0001] Fibers that form nonwoven webs are generally oriented in the xy plane of the web, resulting in a nonwoven web material that is relatively thin and lacks bulk or thickness. The bulk or thickness of a nonwoven web suitable for use in absorbent personal care articles promotes comfort (softness) for the user, surge management, and liquid distribution to adjacent layers. To impart bulk or thickness to a nonwoven web, it is generally desirable for at least a portion of the fibers that form the web to be oriented in the z direction. Traditionally, staple fibers are used to produce bulky nonwoven webs, which can be entangled or rely on preforming processes, such as fiber crimping on a flat wire or drum, and postforming processes, such as creping or pleating the formed web.

[0002] For example, in a process used to increase the volume or bulkiness of nonwoven webs for improved fluid management performance or to enhance the "cloth-like" feel of the webs, the filaments or fibers are often crimped. Multicomponent filaments can be either mechanically crimped or, with the use of appropriate polymers, naturally crimped. However, in the past, there have been difficulties in producing filaments that naturally crimp to the extent required for a particular application. It has also proven very difficult to produce naturally crimped fine filaments, such as filaments with a linear density of less than 2 denier. In particular, the tensile force used to produce fine filaments typically prevents or removes any significant latent crimp properties that may be inherent in the filaments.Additionally, bulky nonwoven materials with desirable combinations of physical properties, particularly combinations of softness, strength, and absorbency, have been produced, although limitations have been identified. For some applications, for example, polymeric materials such as polypropylene may exhibit a desired level of strength but not a desired level of softness. On the other hand, materials such as polyethylene may, in some cases, exhibit a desired level of softness but not a desired level of strength.

[0003] To produce nonwoven materials with desired combinations of physical properties, spunbonded polymer fabrics have been developed from multicomponent or bicomponent filaments and fibers. Typically, one component has different properties than the other, so the filaments exhibit characteristics of both components. For example, one component may be polypropylene, which is relatively strong, and the other component may be polyethylene, which is relatively soft. The end result is a strong yet soft nonwoven fabric. However, the use of different polymers in the multicomponent filaments can make recycling of the multicomponent filaments and webs made from them impractical or impossible if one of the polymers is not recyclable, as it would be difficult to separate the polymers to extract the recyclable polymer.

[0004] In addition, such bicomponent fibers require the use of through-air bonds or similar techniques to bond the fibers into a nonwoven structure. Because of the use of more than one component, stronger and more durable methods such as point bonding cannot be used, as they would lead to melting of the fibers used to improve the softness of the bicomponent fiber.

[0005] Therefore, it would be advantageous to provide a nonwoven web made from a fiber with improved inherent crimping properties without requiring separate crimping treatments (e.g., mechanical crimping). It would also be advantageous to provide a nonwoven web made from an inherently crimped fiber that is easily recycled. Another advantage would be to provide a nonwoven web made from crimped fibers that have undergone point bonding. Furthermore, it would be advantageous to provide a nonwoven web that can be recycled without compromising one or more of the properties of bulk, softness, strength, and absorbency. SUMMARY OF REVELATION

[0006] The present disclosure generally relates to a nonwoven web containing a multicomponent fiber. The multicomponent fiber includes a first polymer-containing component and a second polymer-containing component, wherein the second polymer-containing component contains a rapid crystallization additive and has a solidification and / or crystallization rate that is at least about 10% or greater than the solidification and / or crystallization rate of the first polymer-containing component, and wherein the first polymer component and / or the second polymer component comprises one or more polymers having a melting temperature of at least about 130°C or greater, such as 135°C or greater, such as 140°C or greater, such as 145°C or greater, such as 150°C or greater. Furthermore, the nonwoven web has a TS7 softness value of about 6 or less, as measured as an EMTEC Tissue Softness Analyzer (TSA) output.

[0007] In one aspect, the nonwoven web has a thickness of about 0.5 mm or more. Additionally or alternatively, in one aspect, the nonwoven web has a thickness normalized to the basis weight of about 0.015 mm per g / m 2 (grams per square meter) or more. In another aspect, the nonwoven web has a density of about 76 kg / m 3 or less and / or a TSA stiffness of about 3.25 mm / N or less. In one aspect, the nonwoven web has a tensile peak load of about 4.5 lbf or more.

[0008] Additionally, in one aspect, at least one of the first polymer-containing component and the second polymer-containing component contains more than about 90 wt.% polypropylene, based on the weight of the respective component. In another aspect, the multicomponent fiber contains more than about 70 wt.% polypropylene, based on the weight of the fiber. In one aspect, the multicomponent fibers contain more than about 90 wt.% polypropylene, based on the total weight of the polymers present in the fiber.

[0009] Additionally or alternatively, in one aspect, the rapid crystallization additive is present in the second polymer-containing component in an amount of about 5 wt.% to about 50 wt.%, preferably about 20 wt.% to about 30 wt.%, based on the weight of the second polymer-containing component. In another aspect, the multicomponent fiber includes an average of at least about 8 crimps per cm and has a denier of about 5 or less. Furthermore, in one aspect, the rapid crystallization additive has a melt flow rate (MFR) of between about 81 g / 10 min and about 50 g / 10 min, measured at a temperature of 230°C and a load of 2.16 kg, determined according to ASTM D1238. In another aspect, the rapid crystallization additive is a polypropylene polymer, preferably a polypropylene homopolymer.

[0010] In another aspect, at least one of the first polymer-containing component and the second polymer-containing component includes 50 wt. % or more, preferably about 90 wt. % to about 100 wt. %, based on the total weight of polymer in the respective polymer-containing component, of a polymer having a melting temperature of about 130°C or more, preferably wherein at least one of the first polymer-containing component and the second polymer-containing component is generally free of polyethylene polymers or copolymers. In one aspect, the polymer may have a melting point of about 135°C or more, such as about 140°C or more, such as about 145°C or more, such as about 150°C or more.

[0011] The present disclosure is also generally directed to an absorbent article comprising a nonwoven web according to one or more of the foregoing aspects.

[0012] The present disclosure is also generally directed to a method of forming a nonwoven web comprising: spinning a fiber having at least a first polymer-containing component and a second polymer-containing component, wherein the second polymer-containing component contains a rapid crystallization additive and has a solidification and / or crystallization rate that is at least about 10% or greater than a solidification and / or crystallization rate of the first polymer-containing component; drawing the fibers; depositing the fibers on a forming surface; and subjecting the fibers to a high temperature bonding treatment of about 130°C or greater.

[0013] In one aspect, at least one of the first polymer-containing component and the second polymer-containing component comprises more than about 90 wt.% polypropylene, based on the weight of the respective component. Additionally or alternatively, in one aspect, the fibers comprise more than about 70 wt.% polypropylene, based on the weight of the fiber. In another aspect, the fibers comprise more than about 90 wt.% polypropylene, based on the total weight of the polymers present in the fiber.

[0014] Additionally or alternatively, the multicomponent filaments are continuous or discontinuous. In yet another aspect, the fibers contain an average of at least about two crimps per cm without heat treatment. Furthermore, in one aspect, the high-temperature bonding treatment is a thermal point bond and / or the nonwoven web has a total bond area of ​​about 30% or less. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] A complete and enabling disclosure of the present invention, including the best mode thereof, to those of ordinary skill in the art is set forth more particularly in the remainder of the specification, including reference to the accompanying figure, wherein: Fig. 1 is a schematic drawing of a process line for manufacturing an embodiment of the present invention; Fig. 2A is a schematic drawing illustrating the cross-section of a filament made according to one embodiment of the present invention having polymer components A and B in a side-by-side arrangement; Fig. Figure 2B is a schematic drawing illustrating the cross-section of a filament made according to one embodiment of the present invention having polymer components A and B in an eccentric sheath / core arrangement; Fig.3A is a top-down SEM photograph of Sample 1 of the examples of the present disclosure; Fig. 3B is a top-down SEM image of Control 1 of the examples of the present disclosure; Fig. Figure 3C is a top-down SEM image of Control 2 of the examples of the present disclosure; Fig. 3D is a top-down SEM image of Control 3 of the examples of the present disclosure; Fig. 4A is a SEM cross-sectional image of Sample 1; and Fig. Figure 4B is a SEM cross-sectional image of Control 1.

[0016] The repeated use of reference numerals in this specification and the drawings is intended to represent identical or analogous features or elements of the invention. DETAILED DESCRIPTION OF REPRESENTATIVE ASPECTSDefinitions

[0017] As used herein, the terms "about," "approximately," or "generally," when used to modify a value, mean that the value may be increased or decreased by 10%, such as 7.5%, 5%, such as 4%, such as 3%, such as 2%, such as 1%, and remain within the disclosed aspect. Furthermore, the term "substantially free of," when used to describe the amount of a substance in a material, is not limited to "completely or totally free of," but can also correspond to the absence of any appreciable or detectable amount of said substance in the material. Thus, for example, a material is "substantially free of" a substance if the amount of the substance in the material is less than the accuracy of an industry-recognized instrument or test for measuring the amount of the substance in the material.In certain exemplary embodiments, a material may be "substantially free of" a substance if the amount of the substance in the material is less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.5%, or less than 0.1%, by weight of the material.

[0018] As used herein, the terms "elastomeric" and "elastic" refer to a material that is extensible in at least one direction (such as the CD or MD direction) upon application of a stretching force, and that contracts / recovers approximately to its original dimension upon removal of the stretching force. For example, a stretched material may have a stretched length that is at least 50% greater than the relaxed, unstretched length and that recovers to at least 50% of the stretched length upon removal of the stretching force. A hypothetical example would be a one (1) inch sample of a material that can be stretched to at least 1.50 inches and that recovers to a length no greater than 1.25 inches upon removal of the stretching force. Preferably, the material contracts or recovers to at least 50%, and more preferably, to at least 80% of the stretched length.

[0019] As used herein, the term "fibers" generally refers to elongated extrudates that can be formed by passing a polymer through a forming orifice, such as a die. Unless otherwise noted, the term "fibers" includes discontinuous fibers with a definite length (e.g., stable fibers) and substantially continuous filaments. For example, filaments can have a length much greater than their diameter, such as a length-to-diameter ratio ("aspect ratio") of greater than about 15,000 to 1, and in some cases, greater than about 50,000 to 1.

[0020] As used herein, the term "extensible" generally refers to a material that stretches in the direction of an applied force (e.g., CD or MD direction) by about 50% or more, in some aspects by about 75% or more, in some aspects by about 100% or more, and in some aspects by about 200% or more of its relaxed length or width.

[0021] As used herein, the term "nonwoven web" generally refers to a web having a structure of individual fibers or filaments interwoven, but not in an identifiable manner as in a knit fabric. Examples of suitable nonwoven fabrics or webs include, but are not limited to, meltblown webs, spunbonded webs, bonded carded webs, airlaid webs, coform webs, hydraulically entangled webs, and so on.

[0022] As used herein, the term "meltblown web" generally refers to a nonwoven web formed by a process in which a molten thermoplastic material is extruded through a plurality of fine, usually circular, die capillaries as molten fibers into converging high-velocity gas streams (e.g., air streams) that attenuate fibers of molten thermoplastic material to reduce their diameter, which may be a microfiber diameter. Thereafter, the meltblown fibers are entrained by the high-velocity gas stream and deposited on a collecting surface to form a web of randomly distributed meltblown fibers. One such process is disclosed, for example, in U.S. Patent No. 3,849,241 to Butin et al., which is incorporated herein by reference in its entirety for all purposes.Generally speaking, meltblown fibers can be microfibers that can be essentially continuous or discontinuous, that generally have a diameter of less than 10 microns, and that are generally sticky when deposited on a collecting surface.

[0023] As used herein, the term "spunbonded web" generally refers to a web containing essentially continuous, small-diameter fibers. The fibers are formed by extruding molten thermoplastic material from a plurality of fine, usually round, capillaries from a spinneret, with the diameter of the extruded fibers then being rapidly reduced, for example, by eductive drawing and / or other known spunbond mechanisms. The production of spunbonded webs is described and illustrated, for example, in U.S. Patent Nos. 4,340,563 to Appel, et al., 3,692,618 to Dorschner, et al., 3,802,817 to Matsuki, et al., 3,338,992 to Kinney, 3,341,394 to Kinney, 3,502,763 to Hartman, 3,502,538 to Levy, 3,542,615 to Dobo, et al., and 5,382,400 to Pike, et al., all of which are incorporated herein by reference for all purposes.Spunbond fibers are generally non-sticky when deposited on a collecting surface. Spunbond fibers can sometimes have diameters of less than about 40 microns and often range from about 5 to about 20 microns.

[0024] As used herein, the term "coform" generally refers to composite materials comprising a blend or stabilized matrix of thermoplastic fibers and a second, non-thermoplastic material. Coform materials may be produced, for example, by a process in which at least one meltblowing die head is disposed near a hopper through which other materials are added to the web as it is formed. Such other materials may include, among others, fibrous organic materials, such as woody or non-woody pulp such as cotton, rayon, recycled paper, fluff pulp, and also superabsorbent particles, inorganic and / or organic absorbent materials, treated polymeric staple fibers, and so on. Some examples of such coform materials are described in U.S. Pat. Nos. 4,100,324 to Anderson, et al., 5,284,703 to Everhart, et al., and 5,350,624 to Georger, et al.described, each of which is incorporated herein by reference in its entirety for all purposes.

[0025] As used herein, the term "thermal point bonding" generally refers to a process in which a material is passed between, for example, a patterned roll (e.g., a calender roll) and another roll (e.g., an anvil roll), which may or may not be patterned. Typically, one or both of the rolls are heated.

[0026] As used herein, the term "ultrasonic bonding" generally refers to a process that occurs, for example, by passing a material between a sonotrode and a patterned roll (e.g., anvil roll). Ultrasonic bonding using a stationary sonotrode and a rotating patterned anvil roll is described, for example, in U.S. Patent Nos. 3,939,033 to Grgach, et al., 3,844,869 to Rust Jr., and 4,259,399 to Hill, each of which is incorporated in its entirety by reference for all purposes. In addition, ultrasonic bonding using a rotating sonotrode with a rotating anvil roll is described in U.S. Patent Nos. 5,096,532 to Neuwirth, et al., 5,110,403 to Ehlert, and 5,817,199 to Brennecke, et al. described, each of which is incorporated herein by reference in its entirety for all purposes.Of course, any other ultrasonic bonding technique may be used in the present disclosure.

[0027] A "mechanically crimped filament" is a filament that is crimped by activating a latent crimp inherent in the filaments. For example, in one embodiment, filaments can be mechanically crimped by exposing them to a gas, such as a heated gas, during or after drawing, or by air drying or the use of an air knife.

[0028] "Inherent crimp," as used herein, means that the multicomponent filaments crimp upon solidification and / or crystallization without further crimping treatments, i.e., treatments to produce or activate the crimp. Indeed, the multicomponent filaments of the present disclosure may generally refer to "inherently crimped fibers or filaments" that exhibit a high degree of crimp without the application of additional or subsequent crimping treatments.

[0029] The present invention thus enables simplified and less energy-intensive processes for producing highly crimped multicomponent filaments and nonwoven webs formed therefrom. DETAILED DESCRIPTION

[0030] Generally, the present disclosure relates to a nonwoven web having a unique and advantageous combination of properties. Indeed, the present disclosure has surprisingly discovered that, through the use of a rapid crystallization additive, fibers can be formed that are generally free of low-melting point polymers often required to impart softness. Thus, in addition to a high degree of inherent crimp attributable at least in part to the rapid crystallization additive, the fibers can be formed from one or more polymers having a melting temperature of at least about 130°C or greater, as exemplified in more detail below. The melting temperature can be, for example, about 135°C or greater, about 140°C or greater, about 145°C or greater, or about 150°C or greater.

[0031] Without wishing to be bound by theory, it is believed that the rapid crystallization additive imparts a crystallization gradient within the fiber, resulting in a different crystallization and / or solidification rate between two or more components within the fiber, allowing the fiber to experience inherent crimp. In particular, the rapid crystallization additive may impart a faster solidification and / or crystallization rate to one of the fiber components than to at least one of the polymeric components, resulting in crimping properties similar to those achieved by mechanically crimping the fiber, even without the need for low-melting temperature components.Furthermore, it has been surprisingly discovered that the combination of multicomponent fibers including one or more high-melting-point polymers and a rapid crystallization additive imparts softness properties to the fibers that are not normally present in the absence of a low-melting-point component. Thus, as will be explained in more detail below, nonwoven webs according to the present disclosure exhibit a unique combination of properties, such as softness and bulk, without compromising abrasion resistance and / or other properties.

[0032] For example, as noted above, nonwoven webs according to the present disclosure exhibit excellent bulk even at low basis weights. For example, a nonwoven web according to the present disclosure has a thickness of about 0.5 millimeters (mm) or more, such as about 0.55 mm or more, such as about 0.6 mm or more, such as about 0.65 mm or more, such as about 0.7 mm or more, up to about 1 mm or less, such as about 0.9 mm or less, such as about 0.8 mm or less, or any ranges or values ​​therebetween.

[0033] In another aspect, a nonwoven web according to the present disclosure has a basis weight of about 50 g / m 2 or less, such as 47.5 g / m 2 or less, such as 45 g / m 2 or less, such as 42.5 g / m 2 or less, such as 40 g / m 2 or less, such as 37.5 g / m 2 or less, such as more than about 25 g / m 2or more, such as more than about 30 g / m 2 , or any ranges or values ​​in between.

[0034] Thus, in one aspect, a nonwoven web according to the present disclosure has a thickness (bulkness) that is suitable for a basis weight of about 0.015 mm / g / m 2 (grams per square meter) or more, such as 0.016 mm / g / m 2 or more, such as 0.017 mm / g / m 2 or more, such as 0.018 mm / g / m 2 or more, such as 0.019 mm / g / m 2 or more, such as 0.02 mm / g / m 2 or more, up to about 0.03 mm / g / m 2 or less, such as 0.028 mm / g / m 2 or less, such as 0.025 mm / g / m 2 or less, or any ranges or values ​​in between.

[0035] Furthermore, as will be understood from the foregoing, a nonwoven fabric formed according to the present disclosure may also exhibit improved bulk without compromising strength and / or softness. Without wishing to be bound by theory, the helical crimping of the filaments creates an open web structure with substantial voids between the filaments and bonds the filaments together at points of contact. In one embodiment, the nonwoven web of the present invention has a density of about 76 kg / m 3 or less, such as 75 kg / m 3 or less, such as 70 kg / m 3 or less, such as 60 kg / m 3 or less, such as 50 kg / m 3 or less, such as 40 kg / m 3 or less, such as 30 kg / m 3 or less, such as 25 kg / m 3 or less, such as 20 kg / m 3 or less, such as 10 kg / m 3or less, or any ranges or values ​​therebetween. Surprisingly, the nonwoven web according to the present disclosure also exhibits excellent softness without using a low melting point polymer in the fiber, as discussed above. For example, in one aspect, a nonwoven web according to the present disclosure has a TS7 value of about 6 or less, such as about 5.5 or less, such as about 5 or less, such as about 4.5 or less, such as about 4 or less, such as about 3.5 or less, such as about 3 or less, such as about 2.5 or less, or any ranges or values ​​therebetween. The terms "TS7" and "TS7 value" as used herein refer to an output of an EMTEC

[0036] Tissue Softness Analyzer (TSA) (Emtec Electronic GmbH, Leipzig, Germany) as described in the test procedures section. The units of the TS7 value are dB V. 2rms, however, TS7 values ​​are often referred to herein without reference to units. Furthermore, the nonwoven web according to the present disclosure also exhibits excellent stiffness. For example, a nonwoven web according to the present disclosure, measured using TSA stiffness, the method of which is explained below, may exhibit a stiffness of about 3.25 mm / N or less, such as about 3 mm / N or less, such as about 2.75 mm / N or less, such as about 2.5 mm / N or less, or any ranges or values ​​therebetween.

[0037] An alternative measure of softness may be cup deformation softness, as explained in more detail below. In one aspect, the nonwoven fabric according to the present disclosure may have a total cup deformation energy of about 7.5 N-mm or less, such as about 7 N-mm or less, such as about 6 N-mm or less, such as about 5 N-mm or less, such as about 4 N-mm or less, such as about 3 N-mm or less, or any ranges or values ​​therebetween. Similarly, in one aspect, the nonwoven fabric according to the present disclosure may have a peak cup deformation load of about 45 gf or less, such as about 40 gf or less, such as about 35 gf or less, such as about 30 gf or less, such as about 25 gf or less, or any ranges or values ​​therebetween.

[0038] The nonwoven web according to the present disclosure may also have excellent drape, such as about 4.25 cm or less, such as about 4 cm or less, such as about 3.75 cm or less, such as about 3.5 cm or less, such as about 3.25 cm or less, such as about 3 cm or less, or any ranges or values ​​therebetween.

[0039] Furthermore, a nonwoven web according to the present disclosure also exhibits excellent abrasion resistance. In one aspect, a nonwoven web according to the present disclosure exhibits a Martindale Abrasion Value of about 2 or more, such as about 2.5 or more, such as about 3 or more, such as about 3.5 or more, such as about 4 or more, up to about 5 or less, or any ranges or values ​​therebetween, after 25 cycles, as described in the test methods below.

[0040] Similarly, the nonwoven web according to the present disclosure may have a tensile peak load of about 12.5 lbf (pound-force) or less, such as about 11 lbf or less, such as about 10 lbf or less, such as about 9.5 lbf or less, such as about 9 lbf or less, or such as about 4.5 lbf or more, such as about 5 lbf or more, such as about 6 lbf or more, such as about 7 lbf or more, such as about 8 lbf or more, or any ranges or values ​​therebetween. Additionally or alternatively, the nonwoven web according to the present disclosure may have a modulus of elasticity of about 4000 psi or less, such as about 3500 psi or less, such as about 3000 psi or less, such as about 2500 psi or less, such as about 2000 psi or less, such as about 1500 psi or less, such as about 1000 psi or less, such as about 500 psi or less, or such as about 250 psi or more, or any ranges or values ​​therebetween.

[0041] Furthermore, a nonwoven web according to the present disclosure can exhibit excellent uptake rates (salt uptake), such as about 7.5 seconds or less, such as about 7.25 seconds or less, such as about 7.0 seconds or less, such as about 6.75 seconds or less, or any ranges or values ​​therebetween, as measured according to the following examples. Furthermore, the nonwoven web exhibits excellent rewet or backflow to the surface of the nonwoven web, such as about 1.5 g or less, such as about 1.25 g or less, such as about 1 g or less, or any ranges or values ​​therebetween, as measured according to the following examples.

[0042] Similarly, in one aspect, the nonwoven web has a Lister sweep of about 15 seconds or less, such as about 13 seconds or less, such as about 12 seconds or less.

[0043] In addition, the nonwoven web according to the present disclosure may have an air permeability of about 475 (ft 3 / ft 2 / min) or more, such as 485 (ft 3 / ft 2 / min) or more, such as 495 (ft 3 / ft 2 / min) or more, such as 500 (ft 3 / ft 2 / min) or more, such as 510 (ft 3 / ft 2 / min) or more, such as 520 (ft 3 / ft 2 / min) or more, such as 530 (ft 3 / ft 2 / min) or more, such as 1000 (ft 3 / ft 2 / min) or less, such as 900 (ft 3 / ft 2 / min) or less, such as 800 (ft 3 / ft 2 / min) or less, such as 750 (ft 3 / ft 2 / min) or less, or any range or value in between.

[0044] Nevertheless, as explained above, the solidification and / or crystallization rate of a polymer refers to the rate at which a softened or molten polymer hardens and forms a solid structure. The solidification and / or crystallization rate of a polymer is influenced by various parameters, including the melting temperature and the crystallization rate of the polymer. As explained above, the inherent crimp of fibers is believed to be due, at least in part, to differences in shrinkage properties—i.e., differences in solidification and / or crystallization rates—between two or more components of a multicomponent fiber.

[0045] Indeed, in one aspect, the fibers of the present disclosure may have a side-by-side, eccentric, or sheath-core arrangement and may therefore be generally referred to as "multicomponent," e.g., having at least two different components formed from polymer-containing compositions, wherein the composition forming at least one component of the fiber contains a rapid crystallization additive, as discussed herein. In this way, the differences between the solidification and / or crystallization rates of the two (or more) polymer-containing components result in a fiber with inherent crimp.

[0046] Thus, in one aspect, the fibers according to the present disclosure may have an average of at least about 2 crimps per cm, such as an average of about 4 crimps per cm or more, such as an average of about 8 crimps per cm or more, such as an average of about 12 crimps per cm or more, such as an average of about 16 crimps per cm or more, such as an average of about 20 crimps per cm or more, or any ranges or values ​​in between. Further, as indicated above, such crimp is exhibited without mechanical intervention or further treatments.

[0047] In one aspect, such inherent crimp can result in improved surface properties, which are explained in more detail in the following examples. For example, the nonwoven web can have a randomness or fiber orientation of about 0.35 or more, such as about 0.4 or more, such as about 0.5 or more, such as about 0.6 or more, such as about 0.7 or more, or any ranges or values ​​in between. The nonwoven web can also, in one aspect, have an average surface height of greater than about 75 micrometers, such as about 77.5 micrometers or more, such as about 80 micrometers or more. In one aspect, the nonwoven web can also have a surface area of ​​greater than about 7 micrometers, such as about 7.1 micrometers or more, such as about 7.2 micrometers or more, such as about 7.3 micrometers or more, such as about 7.4 micrometers or more, or any ranges or values ​​in between.In one aspect, the nonwoven web may also have a profile height of about 325 micrometers or more, such as about 350 micrometers or more, such as about 375 micrometers or more, such as about 380 micrometers or more, such as about 390 micrometers or more, or any ranges or values ​​therebetween.

[0048] Furthermore, as stated above, it was surprisingly discovered that the excellent inherent crimp occurred in fine fibers having lower denier than generally possible in crimped fibers. In one aspect, the fibers according to the present disclosure have a denier of about 5 or less, such as about 4.5 or less, such as about 4 or less, such as about 3.5 or less, such as about 3 or less, such as about 2.5 or less, such as about 2 or less, or about 0.5 or more, such as about 1 or more, or any ranges or values ​​therebetween.

[0049] In one aspect, the rapid crystallization additive is a polyolefin having a latent heat of fusion (ΔH f), which is an indicator of the degree of crystallinity, from about 25 to about 210 joules per gram ("J / g"), in some aspects from about 35 to about 150 J / g, in some aspects from about 50 to about 100 J / g, and in some aspects from 60 to about 90 J / g, or any ranges or values ​​therebetween. As explained in more detail below, while the rapid crystallization additive may have one or more of the above latent heat of fusion values, in one aspect the rapid crystallization additive has a latent heat of fusion that is about 1.05 times the latent heat of fusion of at least one of the component polymers of the fiber, such as 1.1 times or more, such as 1.15 times or more, such as 1.2 times or more, such as 1.25 times or more, than a latent heat of fusion of at least one of the component polymers of the multicomponent fiber.It is to be understood, however, that in one aspect, the above ratios refer to two (or more, if any) of the polymeric fiber components, and in one aspect, the ratio refers to all polymeric components of the fiber.

[0050] Additionally, in one aspect, the rapid crystallization additive is a polyolefin having an MFR (melt flow rate) of about 1 gram per 10 minutes to about 50 grams per 10 minutes, such as about 2.5 grams per 10 minutes to about 40 grams per 10 minutes, such as about 5 grams per ten minutes to about 30 grams per ten minutes, such as about 7.5 grams per ten minutes to about 20 grams per ten minutes, such as about 10 grams per ten minutes to about 17.5 grams per ten minutes, or any ranges or values ​​therebetween, at a load of 2.16 kg, determined according to ASTM D1238, and a density of 0.9 g / cm 3 . The latent heat of fusion (ΔH r) and melting temperature can be determined using differential scanning calorimetry (“DSC”) according to ASTM D-3417, as is well known to those skilled in the art.

[0051] For example, in one aspect, the rapid crystallization additive is a polypropylene polymer, which in one aspect may be a polypropylene homopolymer. An example of such a polymer may be ExxonMobil's Achieve Advanced PP3684. Furthermore, in one aspect, the rapid crystallization additive is generally free of phthalates.

[0052] However, regardless of the rapid crystallization additive selected, in one aspect the rapid crystallization additive is present in at least one of the one or more polymer-containing components in an amount of about 50 wt.% or less, such as about 45 wt.% or less, such as about 40 wt.% or less, such as about 35 wt.% or less, such as about 30 wt.% or less, based on the weight of the respective component, or any ranges or values ​​therebetween. Furthermore, in one aspect the rapid crystallization additive is present in the entire fiber-forming composition in an amount of about 25 wt.% or less, such as about 20 wt.% or less, such as about 15 wt.% or less, such as about 12.5 wt.% or less, such as about 10 wt.% or less, or any ranges or values ​​therebetween, based on the weight of the fiber-forming composition.

[0053] Regardless of the rapid crystallization additive used, fibers of the present disclosure are formed from continuous or discontinuous polymeric multicomponent filaments containing at least first and second polymer-containing components. In one aspect, the fibers include a bicomponent fiber, which may be continuous and include a first polymer-containing component A and a second polymer-containing component B. As indicated above, the first and second components A and B are disposed in substantially separate zones across the cross-section of the fiber and extend continuously along the length of the fiber in a side-by-side, eccentric, or sheath-core arrangement.

[0054] In one aspect, as in Fig. 2A and Fig.2B, a fiber having two polymer-containing components may be arranged such that first and second polymer-containing components A and B are arranged, for example, either in a side-by-side arrangement as in Fig. 2A, or in an eccentric sheath / core arrangement, as in Fig. 2B, such that the resulting filaments exhibit an inherent helical crimp. In such an illustration, the polymer-containing component A is the core of the filament and the polymer-containing component B is the sheath in the sheath / core arrangement. However, it is understood that a sheath / core arrangement could be realized with B in the core and A as the sheath. Methods for extruding multicomponent polymeric fibers into such assemblies are well known to those of ordinary skill in the art and are discussed in more detail below.

[0055] However, in one aspect, as noted above, one of the polymer-containing components exhibits one or more properties that result in a faster solidification and / or crystallization rate than the other polymer-containing component(s). For example, in one aspect, one of the two or more polymer-containing components has a higher melting temperature than the other polymer-containing component(s).Furthermore, in one aspect, the solidification and / or crystallization rate of one of the polymer-containing components is about 5% or more faster than the solidification and / or crystallization rate of the other polymer-containing component(s), such as about 10% or more faster, such as at least about 15% or more faster, such as about 20% or more faster, such as about 25% or more faster, such as about 30% or more faster, such as about 40% or more faster, such as about 50% or more faster, such as about 60% or more faster, such as about 70% or more faster, such as about 80% or more faster, such as about 90% or more faster, such as about 100% faster than the solidification and / or crystallization rate of one or more of the further polymer-containing component(s).

[0056] However, in one aspect, one or more of the polymer-containing components may include one or more of the following polymers: Exemplary semi-crystalline polyolefins include polyethylene, polypropylene, and their blends and copolymers. In one particular aspect, a polyethylene is used that is a copolymer of ethylene and an α-olefin, such as a C3-C 20 α-olefin or C3-C 12α-olefin. Suitable α-olefins can be linear or branched (e.g., one or more C1-C3 alkyl branches or an aryl group). Specific examples include 1-butene; 3-methyl-1-butene; 3,3-dimethyl-1-butene; 1-pentene; 1-pentene with one or more methyl, ethyl, or propyl substituents; 1-hexene with one or more methyl, ethyl, or propyl substituents; 1-heptene with one or more methyl, ethyl, or propyl substituents; 1-octene with one or more methyl, ethyl, or propyl substituents; 1-nonene with one or more methyl, ethyl, or propyl substituents; ethyl-, methyl-, or dimethyl-substituted 1-decene; 1-Dodecene and styrene. In one aspect, the α-olefin comonomers are 1-butene, 1-hexene, and 1-octene. The ethylene content of such copolymers can range from about 60 mol% to about 99 mol%, in some aspects from about 80 mol% to about 98.5 mol%, and in some aspects from about 87 mol% to about 97.5 mol%.The α-olefin content may similarly range from about 1 mol% to about 40 mol%, in some aspects from about 1.5 mol% to about 15 mol%, and in some aspects from about 2.5 mol% to about 13 mol%.

[0057] The density of polyethylene can vary depending on the type of polymer used, but generally ranges from about 0.85 g / cm 3 up to about 0.96 g / cm 3 . Polyethylene “plastomers”, for example, have a density in the range of about 0.85 g / cm 3 up to about 0.91 g / cm 3 . Similarly, “linear low-density polyethylene” (“LLDPE”) may have a density in the range of approximately 0.91 g / cm 3 up to about 0.94 g / cm 3 “Low density polyethylene” (“LDPE”) may have a density in the range of 0.91 g / cm 3 up to about 0.94 g / cm 3 and “high density polyethylene” (“HDPE”) can have a density in the range of about 0.94 g / cm 3 up to about 0.96 g / cm 3Densities can be measured according to ASTM 1505.

[0058] In one aspect, particularly suitable polyethylene copolymers are those that are "linear" or "substantially linear." The term "substantially linear" means that the ethylene polymer contains long-chain branches in the polymer backbone in addition to the short-chain branches resulting from the incorporation of comonomers. "Long-chain branch" refers to a chain length of at least 6 carbons. Each long-chain branch can have the same comonomer distribution as the polymer backbone and be as long as the polymer backbone to which it is attached. Preferred substantially linear polymers are substituted with from 0.01 long-chain branches per 1000 carbons to 1 long-chain branch per 1000 carbons, and in some aspects, from 0.05 long-chain branches per 1000 carbons to 1 long-chain branch per 1000 carbons.In contrast to the term "substantially linear," the term "linear" means that the polymer has no measurable or detectable long-chain branches. That is, the polymer is substituted with an average of less than 0.01 long-chain branches per 1000 carbons. Suitable plastomers for use in the present disclosure are ethylene-based copolymer plastomers available under the designation EXACT™ from ExxonMobil Chemical Company of Houston, Texas, ENGAGE™ and AFFINITY™ from Dow Chemical Company of Midland, Michigan, and olefin block copolymers available from Dow Chemical Company of Midland, Michigan under the trade designation INFUSE™, such as INFUSE™ 9807. A polyethylene that is substituted in a.

[0059] Fiber of the present disclosure is DOW™ 61800.41. Other suitable ethylene polymers are available from The Dow Chemical Company under the designations DOWLEX™ (LLDPE), ASPUN™ (LLDPE), and ATTANE™ (ULDPE). Other suitable ethylene polymers are described in U.S. Patent Nos. 4,937,299 to Ewen et al., 5,218,071 to Tsutsui et al., 5,272,236 to Lai et al., and 5,278,272 to Lai et al., which are incorporated herein by reference in their entirety for all purposes.

[0060] Nevertheless, it is understood that in one aspect, the polymer components are formed from one or more ethylene or propylene polymers, such as one or more generally non-elastomeric ethylene or propylene polymers. Thus, in one aspect, the non-elastic polyolefin may include generally inelastic polymers such as conventional polyolefins (e.g., polyethylene), low-density polyethylene (LDPE), Ziegler-Natta-catalyzed linear low-density polyethylene (LLDPE), etc., ultra-low-density polyethylene (ULDPE), polypropylene, polybutylene, etc.; polytetrafluoroethylene; polyesters, e.g., polyethylene terephthalate (PET), etc.; polyvinyl acetate; polyvinyl chloride acetate; polyvinyl butyral; acrylic resins, e.g., polyacrylate, polymethyl acrylate, polymethyl methacrylate, etc.; polyamides, e.g., nylon; polyvinyl chloride; polyvinylidene chloride; polystyrene; polyvinyl alcohol; polyurethanes; polylactic acid; copolymers and blends thereof; and so on.For example, one or more of the polymer components may include an LLDPE available from Dow Chemical Co. of Midland, Michigan, such as DOWLEX™ 2517 or DOWLEX™ 2047, or a combination thereof, or available from Westlake Chemical Corp. of Houston, Texas. Additionally, in one aspect, the one or more polymer components may be other suitable ethylene polymers, such as those available from The Dow Chemical Company under the designations ASPUN™ (LLDPE) and ATTANE™ (ULDPE), or from The Dow Chemical Company under the designations DOWLEX™ (LLDPE), ASPUN™ (LLDPE), and ATTANE™ (ULDPE).

[0061] Propylene polymers are also suitable for use as semi-crystalline polyolefins. Suitable plastomeric propylene polymers may include, for example, copolymers or terpolymers of propylene, copolymers of propylene with an α-olefin (e.g., C3-C 20), such as ethylene, 1-butene, 2-butene, the various pentene isomers, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-unidecene, 1-dodecene, 4-methyl-1-pentene, 4-methyl-1-hexene, 5-methyl-1-hexene, vinylcyclohexene, styrene, etc. The comonomer content of the propylene polymer may be about 35 wt.% or less, in some aspects from about 1 wt.% to about 20 wt.%, and in some aspects from about 2 wt.% to about 10 wt.%. Preferably, the density of the polypropylene (e.g., propylene / α-olefin copolymer) may be 0.91 grams per cubic centimeter (g / cm 3 ) or less, in some aspects from 0.85 to 0.88 g / cm 3 and in some aspects of 0.85 g / cm 3 up to 0.87 g / cm 3Suitable propylene-based copolymer plastomers are commercially available under the designations VISTAMAXX™ (e.g., 2330, 6202, and 6102), a propylene-ethylene copolymer-based plastomer, from ExxonMobil Chemical Co. of Houston, Texas; FINA™ (e.g., 8573) from Atofina Chemicals of Feluy, Belgium; TAFMER™, from Mitsui Petrochemical Industries; and VERSIFY™, from Dow Chemical Co. of Midland, Michigan. Other examples of suitable propylene polymers are described in U.S. Patent Nos. 6,500,563 to Datta, et al.; 5,539,056 to Yang, et al.; and 5,596,052 to Resconi, et al. which are hereby incorporated by reference in their entirety for all purposes.

[0062] However, it is understood that in one aspect, one or more of the polymers in one or more of the polymer-containing components are formed from a propylene polymer and / or copolymer, such as, in one aspect, a polypropylene homopolymer. In one aspect, the polyolefin is a propylene homopolymer or copolymer (e.g., random or block) containing about 10 wt. % or less of comonomers (e.g., α-olefins), and in some embodiments, about 2 wt. % or less. If desired, the propylene polymer can be syndiotactic or isotactic. The term "syndiotactic" generally refers to tacticity in which a substantial portion, if not all, of the methyl groups alternate on opposite sides along the polymer chain. On the other hand, the term "isotactic" generally refers to tacticity in which a substantial portion, if not all, of the methyl groups alternate on the same side along the polymer chain.Such polymers are typically formed using a Ziegler-Natta catalyst, either alone or in combination with a small amount of an α-olefin comonomer. Isotactic polymers, for example, typically have a density in the range of 0.90 to 0.94 g / cm. 3as determined according to ASTM 1505-10. Commercially available propylene homopolymers may include, for example, Metocene™ MF650Y and MF650X (Basell Polyolefins), PP2252E1, PP 3155 or PP 2252 (ExxonMobil), and M3661 PP (Total Refining and Chemicals). Other examples of suitable propylene polymers may be found in U.S. Pat. No. 6,500,563 to Datta et al.; U.S. Pat. No. 5,539,056 to Yang et al.; and U.S. Pat. No. 5,596,052 to Resconi et al. Additionally or alternatively, one or more of the polymer components are formed from a propylene-based copolymer plastomer, such as a propylene-based copolymer commercially available under the designations VISTAMAXX™ (e.g., 2330, 6202, 6102, and 7050), a propylene-ethylene copolymer-based plastomer from ExxonMobil Chemical Co. of Houston, Texas; FINA™ (e.g., 8573) from Atofina Chemicals of Feluy, Belgium; TAFMER™, available from Mitsui Petrochemical Industries; and VERSIFY™, available from Dow Chemical Co. of Midland, Michigan.

[0063] However, as stated above, in one aspect, one or more of the polymers in one or more of the polymer-containing components includes a spunbond polypropylene without an α-olefin comonomer, such as a polypropylene homopolymer, also referred to as spunbond polypropylene.

[0064] In one aspect, a polypropylene homopolymer is present in one or more of the polymer-containing components in an amount of about 15 wt.% or more, such as about 20 wt.% or more, such as about 25 wt.% or more, such as about 30 wt.% or more, such as about 35 wt.% or more, such as about 40 wt.% or more, such as about 45 wt.% or more, such as about 50 wt.% or more, such as about 55 wt.% or more, based on the weight of one or more of the polymer-containing components. Additionally, in one aspect, a polypropylene homopolymer is present in an amount of about 50 wt.% or more, such as about 55 wt.% or more, such as about 60 wt.% or more, such as about 65 wt.% or more, such as about 70 wt.% or more, based on the total weight of the fiber-forming composition.

[0065] Additionally, in one aspect, a polypropylene used in one or more of the polymer components may have a melt flow rate of about 5 to about 200 grams per 10 minutes, such as about 15 to about 150 grams per 10 minutes, such as about 17.5 to about 100 grams per 10 minutes, such as about 20 grams to about 55 grams per ten minutes at 230°C and a load of 2.16 kg, determined according to ASTM D1238.

[0066] Furthermore, in one aspect, polypropylene copolymers having small comonomer amounts of ethylene may be included in one or more of the polymer-containing components of the fiber-forming composition. When present, the ethylene comonomer is present in an amount of about 10 wt.% or less, such as about 7.5 wt.% or less, such as about 5 wt.% or less, such as about 2.5 wt.% or less, such as about 1 wt.% or less, such as about 0.5 wt.% or less, such as about 0.1 wt.% or less, based on the total weight of the polymers in the fiber-forming composition. In one aspect, the propylene copolymer may be generally free of non-polypropylene monomers, such as polyethylene comonomers.Alternatively, as noted above, in one aspect, the percentage of non-polypropylene polymers may refer to polymers having a melting temperature of less than 130°C, including polypropylene homopolymers or copolymers having a melting temperature of less than 130°C. Indeed, as noted above, it has surprisingly been found that the addition of a rapid crystallization additive improves the softness and crystallization of the multicomponent fiber without the use of low-melting-point polymers. Furthermore, such a fiber-forming composition allows for the use of more temperature-intensive bonding processes, such as point bonding, as explained in more detail below, so that the nonwoven web formed from the fibers of the present disclosure can exhibit both softness and strength properties in addition to improved bulk.

[0067] Nevertheless, as explained in more detail below, it is to be understood that in one aspect, each of the one or more polymer-containing components may contain two or more, such as three or more, such as four or more, such as five or more, different polymers. However, as stated above, it is to be understood that in one aspect, regardless of the number of polymers in each polymer-containing component, each of the polymers is from the same general class of polyolefins, such as, for example, in one aspect, each of the polymers is a polypropylene polymer containing less than 10% comonomers, as explained above. Further, regardless of the number of polymers included in the one or more polymer-containing components, the polymer(s) may generally be free of comonomers and thus may consist entirely of homopolymers, which, as stated above, may further enhance the recyclability of the nonwoven fabrics of the present disclosure.

[0068] Any of a variety of known techniques can generally be employed to form polyolefin polymers. For example, olefin polymers can be formed using a free radical or a coordination catalyst (e.g., Ziegler-Natta). Preferably, the olefin polymer is formed from a complex-coordinative single-site catalyst, such as a metallocene catalyst. Such a catalyst system produces ethylene copolymers in which the comonomer is randomly distributed within a molecular chain and uniformly distributed across the different molecular weight fractions. Metallocene-catalyzed polyolefins are described, for example, in U.S. Pat. Nos. 5,571,619 to McAlpin et al.; 5,322,728 to Davis et al.; 5,472,775 to Obiieski et al.; 5,272,236 to Lai et al., and 6,090,325 to Wheat, et al., which are incorporated herein by reference in their entirety for all purposes.Examples of metallocene catalysts include bis(n-butylcyclopentadienyl)titanium dichloride, bis(n-butylcyclopentadienyl)zirconium dichloride, bis(cyclopentadienyl)scandium chloride, bis(indenyl)zirconium dichloride, bis(methylcyclopentadienyl)titanium dichloride, bis(methylcyclopentadienyl)zirconium dichloride, cobaltocene, cyclopentadienyltitanium trichloride, ferrocene, hafnocene dichloride, isopropyl(cyclopentadienyl-1-flourenyl)zirconium dichloride, molybdocene dichloride, nickelocene, niobocene dichloride, ruthenocene, titanocene dichloride, zirconocene chloride hydride, zirconocene dichloride, and so on. Polymers prepared using metallocene catalysts typically have a narrow molecular weight range. Metallocene-catalyzed polymers can, for example, have polydispersity numbers (M). w / M n ) of less than 4, a controlled short chain branching distribution and a controlled isotacticity.

[0069] However, as stated above, in an example such as Fig. 2A and Fig. 2B, polymer-containing component A is a polypropylene polymer and polymer-containing component B is a polypropylene polymer. In one aspect, the weight ratio of the first polymer-containing component (component A) to the second polymer-containing component (component B) is about 50:50 to about 90:10, such as about 50:50 to about 65:35, or about 50:50 to about 75:25.

[0070] However, as indicated above, in one aspect, one or more of the polymer-containing components also include additional ingredients. Generally, additional ingredients are present in an amount of about 30 wt.% or less, such as about 25 wt.% or less, such as about 22.5 wt.% or less, such as about 20 wt.% or less, such as about 17.5 wt.% or less, such as about 15 wt.% or less, such as about 12.5 wt.% or less, such as about 10 wt.% or less, such as about 7.5 wt.% or less, such as about 5 wt.% or less, based on the weight of a respective individual polymer-containing component or based on the total weight of the fiber-forming composition. Additional ingredients for the multicomponent filaments of the present invention include, for example, softness / bulk improvers, pigments, fillers, and slip aids.Other inert additives, as known in the art, may be included, as will be understood by those skilled in the art. For example, in one aspect, one or more of the polymer-containing components may include one or more inorganic fillers. Thus, in one aspect, the one or more of the polymer-containing components include one or more of calcium carbonate (CaCO3), various types of clay, silica (SO2), alumina, barium sulfate, sodium carbonate, talc, magnesium sulfate, titanium dioxide, zeolites, aluminum sulfate, cellulosic powders, diatomaceous earth, magnesium sulfate, magnesium carbonate, barium carbonate, kaolin, mica, carbon, calcium oxide, magnesium oxide, aluminum hydroxide, wood pulp powder, wood powder, cellulose derivatives, polymer particles, chitin, and chitin derivatives. In one aspect, the inorganic particles may include calcium carbonate, diatomaceous earth, or combinations thereof.

[0071] In one aspect, one or more of the polymer-containing components may include one or more pigment particles. In one aspect, one or more pigment particles are included in one or more of the polymer-containing components in an amount of from about 0.1 wt.% to about 5 wt.% pigment particles, based on the total weight of the component, such as from about 0.5 wt.% to about 4.5 wt.%, such as from about 1 wt.% to about 4 wt.%, such as from about 1.5 wt.% to about 3.5 wt.%, or any ranges or values ​​therebetween. Suitable pigments may include white pigments such as titanium dioxide and / or zinc dioxide. In one aspect, the pigment is a white pigment such as SCC-4837, titanium dioxide, available from Standridge Color Corporation, Social Circle, GA.

[0072] Suitable softness / bulk improvers include polypropylene / polyethylene copolymers such as Vistamaxx 7050, a polypropylene / polyethylene copolymer containing 13 wt% ethylene and a mass flow rate of 45 g / 10 min at 230 °C and a load of 2.16 kg, determined according to ASTM D1238, available from ExxonMobil, and Americhem 48137, a secondary fatty acid amide available from Americhem of Cuyahoga Falls, OH.

[0073] Suitable slip aids include primary and secondary amides. In one aspect, the slip aid is a fatty acid amide, such as a suitable amide compound derived from the reaction between a fatty acid and ammonia or an amine-containing compound (e.g., a compound containing a primary amine group or a secondary amine group) to form a secondary amide. The fatty acid may be any suitable fatty acid, such as a saturated or unsaturated C8-C 28-fatty acid or a saturated or unsaturated C 12 -C 28 -Fatty acid. In certain aspects, the fatty acid can be erucic acid (i.e., cis-13-docosanic acid), oleic acid (i.e., cis-9-octadecenoic acid), stearic acid (octadecanoic acid), behenic acid (i.e., docosanoic acid), arachidic acid (i.e., arachidic acid or eicosanoic acid), palmitic acid (i.e., hexadecanoic acid), and mixtures or combinations thereof. The amine-containing compound can be any suitable amine-containing compound, such as fatty amines (e.g., stearylamine or oleylamine), ethylenediamine, 2,2'-iminodiethanol, and 1,1'-iminodipropan-2-ol.

[0074] In one aspect, the secondary amide may be a fatty acid amide having the structure of any of the formulas (I)-(III): wherein R 14 , R 15 , R 16 and R 18 independently from C7-C 27 -alkyl groups and C7-C 27 -alkenyl groups and in some aspects from C 11 -C 27-alkyl groups and C 11 -C 27 -alkenyl groups are selected; and R 17 is selected from C8-C 28 -alkyl groups and C8-C 28 -alkenyl groups and in some aspects from C 12 -C 28 -alkyl groups and C 12 -C 28 -alkenyl groups.

[0075] The fatty acid amide may, for example, have the structure of formula (I), where R 14 - CH2(CH2) 10 CH=CH(CH2)7CH3 (erucamide) and R 15 -CH2(CH2) 15 CH3, or where R 15 - CH2(CH2)6CH=CH(CH2)7CH3 (oleamide) and R 15 -CH2(CH2) 13 CH3. Likewise, in other aspects, the fatty acid amide may have the structure of formula (II), in which R 16 CH2(CH2) 15CH3 or - CH2(CH2)6CH=CH(CH2)7CH3. The secondary amide may also contain a mixture of two or more such fatty acid amides. However, in one aspect, such as the examples explained below, the secondary amide additive is erucamide, oleamide, oleyl palmitamide, ethylene bis-oleamide, stearyl erucamide, or a combination thereof. Of course, in one aspect, the secondary amide may also be a non-fatty acid amide.

[0076] Preferably, the slip aid is present in at least one of the one or more polymer-containing components in an amount between about 0.1 wt% and about 1 wt% or between about 0.2 wt% and about 0.5 wt%, based on the weight of the respective polymer-containing component.

[0077] Regardless of the components selected / formed, nonwoven webs formed according to the present disclosure are particularly suitable for manufacturing various products, including liquid and gas filters, personal care articles, and clothing materials such as surge layers for personal care products, acoustic and thermal insulation, packaging materials, cushioning, absorbents, filtering, and cleaning materials. Personal care articles include infant care products such as disposable baby diapers, child care products such as training pants, and adult care products such as incontinence products and feminine hygiene articles. Suitable garments include safety wear, workwear, and the like.

[0078] However, the present disclosure is also generally directed to a method of forming a nonwoven web as discussed above. A method of making nonwoven webs according to the present disclosure will now be described with reference to Fig. 1. The following procedure is similar to that described in U.S. Pat. No. 5,382,400 to Pike et al., which is incorporated herein by reference in its entirety.

[0079] Referring to Fig.1, a process line 10 is disclosed for preparing one aspect of the present disclosure. In one aspect, the filaments described herein may be produced, for example, by a "closed" or "open" spunbond system, as described below. The process line 10 is configured to produce continuous bicomponent fibers, however, it is understood that the present disclosure contemplates nonwoven fabrics made from multicomponent fibers having more than two components. For example, the nonwoven fabric of the present disclosure may be produced with fibers having three or four or more components, as discussed above.

[0080] The process line 10 includes a pair of extruders 12a and 12b for separately extruding a polymer-containing component A and a polymer-containing component B. The polymer-containing component A is fed from a first hopper 14a into the respective extruder 12a, and the polymer-containing component B is fed from a second hopper 14b into the respective extruder 12b. From the extruders 12a and 12b, the polymer-containing component A is fed to a spinneret 18 via a polymer line 16a and 16b, respectively. Those skilled in the art will appreciate that the polymers containing the respective polymer-containing component can be dry-blended with any desired additives in the hopper or prior to incorporation into the hopper.Thus, in one aspect, when the polymer-containing component is the faster crystallizing component, the polymer may be dry blended with the fast crystallizing agent and any additives such as slip agents, pigments, and the like prior to extrusion.

[0081] Spinnerets for extruding multicomponent fibers are well known to those skilled in the art and will therefore not be described in detail here. However, the spinneret 18 includes a housing containing a die pack including a plurality of stacked plates having a pattern of openings arranged to create flow paths for separately directing the polymer-containing components A and B through the spinneret. The spinneret 18 has openings arranged in one or more rows. The spinneret openings form a downwardly projecting filament curtain as the polymers are extruded through the spinneret. For the purposes of the present disclosure, the spinneret 18 may be arranged to form side-by-side, eccentric, or sheath / core multicomponent fibers, as shown in Fig. 2A and Fig.2B. The process line 10 also includes a quench blower 20 positioned adjacent to the fiber curtain extending from the spinneret 18. Air from the quench blower 20 quenches the filaments extending from the spinneret 18. The quench air can be supplied from one side of the filament curtain, as shown in Fig. 1, or both sides of the filament curtain.

[0082] A fiber drawing unit or aspirator 22 may also be disposed below the spinneret 18 and receive the quenched fibers. Fiber drawing units or aspirators for use in melt spinning or spunbonded polymers are well known in the art, as discussed above. Suitable fiber drawing units for use in the process of the present disclosure include a linear fiber aspirator of the type shown in U.S. Pat. No. 3,802,817 and educational guns of the type shown in U.S. Pat. Nos. 3,692,618 and 3,423,266, the disclosures of which are incorporated herein by reference.

[0083] Deposition of the fibers is assisted by a vacuum beneath the wire provided by a suction box 30, which draws the fibers onto the forming wire 26. The forming wire 26 is porous, so the vertical airflow created by the suction box 30 can cause the fibers to settle. In one aspect of the present disclosure, the flow velocity of this airflow can be kept relatively low to enhance the tendency of the fibers to remain aligned in the MD direction. Alternatively, the suction box can include sections extending in the MD direction to interrupt the vertical airflow at the point where the fibers are laid onto the moving web, allowing the fibers a higher degree of MD alignment. An example of such a technique is described, for example, in U.S. Patent No. 6,331,268.Of course, other techniques may be used to maintain the fibers aligned in the machine direction. For example, deflector vanes or other mechanical elements may be used, as described in U.S. Patent Nos. 5,366,793 and 7,172,398. The direction of the air flow used to dampen the fibers during their formation may also be adjusted to influence machine direction alignment, as described in U.S. Patent No. 6,524,521. In addition to the method described above, other known techniques for forming the fibers may be used. In one aspect, for example, the fibers may be quenched after formation and then deposited directly onto a forming screen without prior drawing in the manner described above.In these aspects, as described above, the flow velocity of this air stream may be kept relatively low to enhance the tendency of the fibers to remain aligned in the MD direction. However, it should be understood that in one aspect, the fibers are not primarily aligned in the MD direction.

[0084] Surprisingly, the present disclosure has discovered that the fibers formed according to the present disclosure can exhibit additional bulk and texture through the use of a textured forming screen. Indeed, the inherent crimp and high-temperature properties of the fibers allow the fibers to retain a textured surface imparted by the textured forming screen 26. Without wishing to be bound by theory, it is believed that such characteristics are due, at least in part, to the ability of the inherently crimped fibers to retain their shape and their ability to withstand high-temperature bonding processes.It is explained that high-temperature bonding processes such as point bonding can be carefully chosen to maintain an imparted texture, while lower-temperature processes and mechanical crimp activation can remove the texture from the web. However, any desired texture can be imparted by using a suitable forming screen 26.

[0085] In any case, the resulting fibers can then be bonded to form a consolidated, coherent nonwoven web structure. In the present disclosure, any suitable bonding technique may generally be used, such as adhesive or autogenous bonding (e.g., fusion and / or self-adhesion of the fibers without an externally applied adhesive). Autogenous bonding can be achieved, for example, by contacting the fibers while they are semi-molten or tacky, or simply by mixing a tackifying resin and / or a solvent with the polymer composition used to form the fibers. Suitable autogenous bonding techniques include ultrasonic bonding, thermal bonding, through-air bonding, and so on. In thermal point bonding, for example, a nip is typically formed between two rolls, at least one of which is patterned.In ultrasonic bonding, however, a nip is usually formed between a sonotrode and a patterned roller.

[0086] Nevertheless, as stated above, it is understood that the fibers according to the present disclosure are particularly suitable for high-temperature bonding processes such as thermal point bonding. Indeed, the present disclosure has surprisingly discovered that by combining a rapid crystallization additive and high-melt temperature polymer(s), a nonwoven according to the present disclosure can be thermally point bonded without melt damage to the web. Thus, in one aspect, as stated above, the nonwoven web according to the present disclosure can be subjected to a high-temperature bonding process such as thermal point bonding, so that the nonwoven web, in addition to the advantageous properties already discussed, exhibits improved abrasion resistance and strength compared to low-temperature bonding applications such as through-air bonding.

[0087] Regardless, the particular nature of the weave pattern can vary as desired. For example, one suitable weave pattern is known as the "S-weave" pattern and is described in U.S. Patent No. 5,964,742 to McCormack et al. Another suitable weave pattern is known as the "rib knit" pattern and is described in U.S. Patent No. 5,620,779 to Levy et al. Another suitable pattern is the "wire mesh" pattern, which has a weave density of about 200 to about 500 weave sites per square inch, and in some aspects, about 250 to about 350 weave sites per square inch. Of course, other weave patterns can be used, as described in U.S. Patent Nos. 3,855,046 to Hansen et al.; 5,962,112 to Haynes et al.; 6,093,665 to Sayovitz et al.; D375,844 to Edwards et al.; D428,267 to Romano et al.; and D390,708 to Brown.Additionally, a bond pattern may also be used that includes bond regions generally oriented in the machine direction and having an aspect ratio of about 2 to about 100, in some aspects from about 4 to about 50, and in some aspects from about 5 to about 20. The pattern of bond regions is also typically selected such that the nonwoven web has a total bond area of ​​less than about 50% (as determined by conventional optical microscopy techniques), and in some aspects, about 30% or less, such as about 25% or less, such as about 20% or less, such as about 17.5% or less, such as about 15% or less, such as about 12.5% ​​or less, such as about 10% or less, or any ranges or values ​​therebetween, in an aspect.

[0088] Thus, as in Fig.1, the process line 10 further includes a bonding device such as thermal point bonding rolls 34 (shown in phantom) or a through-air binder 36. Thermal point binders and through-air binders are well known to those skilled in the art and are not disclosed in detail here. The through-air binder 36 generally includes a perforated roll 38 that receives the web and a hood 40 surrounding the perforated roll. Finally, the process line 10 includes a winding roll 42 for receiving the finished fabric.

[0089] Finally, the bonded nonwoven web is wound onto the winding roll 42 and is ready for further treatment or use. When used to manufacture liquid-absorbent articles, the fabric of the present invention may be treated with conventional surface treatments or contain conventional polymer additives to increase the wettability of the fabric. For example, the fabric of the present invention may be treated with polyalkylene oxide-modified siloxanes and silanes, such as polyalkylene oxide-modified polydimethylsiloxane, as disclosed in U.S. Pat. No. 5,057,361. Such a surface treatment improves the wettability of the fabric.

[0090] The spunbonded web may also be subjected to one or more additional post-treatment steps, as is known in the art. For example, the spunbonded web may be stretched in the cross-machine direction using known techniques such as tenter frame stretching, grooved roll stretching, etc. The spunbonded web may also be subjected to other known processing steps, such as perforation, heat treatments, etc.

[0091] In one aspect, the spunbonded web formed according to the present disclosure can form all or part of a nonwoven facesheet of a composite. Of course, the nonwoven facesheet can also include additional layers (e.g., nonwoven webs, films, strands, etc.) if desired. For example, the facesheet can include two (2) or more layers, and in some aspects, three (3) to ten (10) layers (e.g., 3 or 5 layers). In one aspect, the nonwoven facesheet can include, for example, an inner nonwoven layer (e.g., meltblown or spunbonded) sandwiched between two outer nonwoven layers (e.g., spunbonded). For example, the inner nonwoven layer can be formed from the spunbonded web of the present disclosure, and one or both of the outer nonwoven layers can be formed from the spunbonded web of the present disclosure or a conventional nonwoven web.Alternatively, the inner nonwoven layer may be formed from the spunbonded web of the present disclosure or a conventional nonwoven web, and one or both of the outer nonwoven layers may be formed from the spunbonded web of the present disclosure. Various techniques for forming laminates of this type are described in U.S. Patent Nos. 4,041,203 to Brock et al.; 5,213,881 to Timmons et al.; 5,464,688 to Timmons et al.; 4,374,888 to Bornslaeger; 5,169,706 to Collier et al.; and 4,766,029 to Brock et al. The cover layer may have other configurations and any number of layers, such as: E.g., a spunbond-meltblown-spunbond (“SMMS” laminate), a spunbond-meltblown laminate (“SM” laminate), etc.

[0092] Regardless of the method by which the spunbonded web is formed or the number of layers in the facesheet, in one aspect, the nonwoven facesheet can be used in a laminate by laminating the nonwoven facesheet to an elastic film or other carrier or layer, as discussed above. Lamination can be accomplished using a variety of techniques, such as adhesive bonding, thermal point bonding, ultrasonic bonding, etc. The particular bonding pattern is not critical to the present disclosure, and any bonding pattern, aperture formation, and stretching discussed above with respect to the spunbonded web can also be used for lamination.

[0093] For example, in one aspect, an elongation ratio of about 1.5 or more, or 2 to 6, or 2.5 to 7.0, or 3.0 to 5.5 is used to achieve the desired level of tension in the film during lamination. The elongation ratio can be determined by dividing the final length of the film by its original length. The elongation ratio can also be approximately equal to the draw ratio, which can be determined by dividing the linear speed of the film during lamination (e.g., speed of the nip rolls) by the linear speed at which the film is formed (e.g., speed of the casting rolls or blown nip rolls). Whether laminated to a carrier or used alone as a nonwoven web, the spunbonded web can be used in a wide variety of applications. As mentioned above, the spunbonded web can be used, for example, in an absorbent article.An "absorbent article" generally refers to any article capable of absorbing water or other liquids. Examples of some absorbent articles include, but are not limited to, absorbent personal care articles, such as diapers, training pants, absorbent underpants, incontinence products, feminine care products (e.g., sanitary napkins, panty liners, etc.), swimwear, baby wipes, and so on; medical absorbent articles, such as garments, fenestration materials, underpads, bed pads, bandages, absorbent drapes, and medical wipes; catering wipes; clothing articles, and so on, and are particularly well-suited for wearable articles due to their enhanced clothing-like feel.

[0094] Several examples of such absorbent articles are described in U.S. Patent Nos. 5,649,916 to DiPalma et al.; 6,110,158 to Kielpikowski; and 6,663,611 to Blaney et al. Other suitable articles are described in U.S. Patent Application No. 2004 / 0060112 A1 to Fell et al., as well as U.S. Patent Nos. 4,886,512 to Damico et al.; 5,558,659 to Sherrod et al.; 6,888,044 to Fell et al.; and 6,511,465 to Freiburger et al. Materials and processes suitable for forming such absorbent articles are widely known to those skilled in the art. Typically, absorbent articles include a substantially liquid-impermeable layer (e.g., outer cover), a liquid-permeable layer (e.g., bodyside liner, surge layer), and an absorbent core. In a particular aspect, the nonwoven fabric according to the present disclosure may be suitable for one or more liquid-permeable layers.

[0095] The present disclosure will be better understood by reference to the following examples. Test Methods: TSA

[0096] TS7 and TS750 values ​​were measured using an EMTEC Tissue Softness Analyzer ("TSA") (Emtec Electronic GmbH, Leipzig, Germany). The TSA consists of a rotor with vertical blades that rotate on the test piece and apply a defined contact pressure. The contact of the vertical blades with the test piece generates vibrations that are recorded by a vibration sensor. The sensor then sends a signal to a PC for processing and display. The signal is displayed as a frequency spectrum. To measure TS7 and TS750 values, the blades are pressed against the sample with a load of 100 mN and the blades rotate at 2 revolutions per second.

[0097] To measure TS7 and TS750 values, two different frequency analyses are performed. The first frequency analysis is performed in the range from approximately 200 Hz to 1000 Hz, with the TS750 value being recorded as the amplitude of the peak occurring at 750 Hz. The TS750 value represents the surface smoothness of the sample. A high amplitude peak correlates with a rougher surface. A second frequency analysis is performed in the range from 1 to 10 kHz, with the TS7 value being recorded as the amplitude of the peak occurring at 7 kHz. The TS7 value represents the softness of the sample. A lower amplitude correlates with a softer sample. Both TS750 and TS7 values ​​have the units dB V 2 rms. The samples were measured in an environment with 50% relative humidity and at 22 °C.

[0098] To measure the stiffness properties of the test specimen, the rotor is first loaded up to a load of 100 mN against the test specimen. Then, the rotor is gradually loaded further until the load reaches 600 mN. The instrument records the specimen displacement (µm) versus load (mN) as the specimen is loaded and outputs a curve over the range 100 to 600 mN. The modulus value "E" is given as the slope of the displacement-stress curve for this first loading cycle in units of mm displacement / N load force. After completing the first loading cycle from 100 to 600 mN, the instrument reduces the load back to 100 mN and then increases the load again to 600 mN for a second loading cycle. The slope of the displacement-stress curve from the second loading cycle is referred to as the "D" modulus value. Shell deformation softness:

[0099] The softness of a specimen can also be measured according to the "cup deformation test" per WSP Standard Test No. 402.0 (09), which evaluates softness by measuring the peak load ("cup deformation load") required for a straight-formed foot (15 mm diameter, Model 12) to deform a specimen (153 mm x 153 mm) into an inverted cup shape while the cup-shaped specimen remains surrounded by a forming cup / cylinder (approximately 58 mm high with a diameter of 35 mm) to maintain uniform deformation. An average of 5 readings was used. The foot and cup are aligned to avoid contact between the cup walls and the foot, which could affect the readings. The peak load is measured in grams while the foot descends at a rate of approximately 380 mm per minute.The shell deformation test also provides a total energy value required to deform a specimen (the "shell deformation energy"), which is the energy from the start of the test to the peak load point—that is, the area under the curve defined by the load in grams on one axis and the foot distance in millimeters on the other axis. Therefore, the shell deformation energy is expressed in g*mm. Lower shell deformation values ​​indicate a softer material. A suitable device for measuring shell deformation is an FTD-G-500 load cell (500-gram range) available from the Schaevitz Company of Pennsauken, NJ. Train peak load

[0100] The specimen (3" CD x 6" MD) was held between clamps measuring 25.4 mm x 76 mm front and back. The gripping surfaces were rubberized, and the longer dimension of the grip was perpendicular to the direction of tension. The grip pressure was maintained pneumatically at a pressure of 60 pounds per square inch. The tensile test was conducted at a speed of 305 mm per minute with a gauge length of 76 mm and a fracture sensitivity of 65%.

[0101] Five specimens were tested by applying the test load along the machine direction. The peak tensile forces of each tested specimen were arithmetically averaged to determine the MD tensile strength. Air permeability

[0102] The air permeability was measured using a Textest FX3300 air permeability tester from Textest Ltd., Zurich, Switzerland, in cubic feet of air per minute passing through an area of ​​38 cm 2(7 cm diameter circle). All tests were conducted in a laboratory at a temperature of 23 ± 2 °C and 50 ± 5% relative humidity. Specifically, a nonwoven fabric is allowed to dry and condition for at least 12 hours prior to testing in the laboratory at 23 ± 2 °C and 50 ± 5% relative humidity. The nonwoven fabric is clamped into the 7 cm diameter fabric test port, and the tester is set to a pressure drop of 125 Pa. Placing folds or wrinkles across the fabric test port should be avoided whenever possible. The instrument is switched on by applying clamping pressure to the sample. The airflow at 125 Pa pressure drop is recorded after 15 seconds of airflow to achieve a steady-state value. Lister recording:

[0103] The Lister test is used to determine the liquid throughput time of a nonwoven test sample. The throughput time is the time required for a specific amount of liquid to be absorbed by the nonwoven fabric. A suitable test method is EDANA Test No. 150.9-1 (Liquid Throughput Time Test). According to one method, a 4 in. x 4 in. (10.2 cm x 10.2 cm) sample of the selected nonwoven material is weighed and placed on a 4 in. x 4 in. (10.2 cm x 10.2 cm) assembly of 5-ply filter paper, Type ERT FF3 (available from Hollingsworth and Vose Co., East Walpole, Mass.). The sample assembly is then placed under a Lister tester. A suitable Lister tester is available from W. Fritz Mezger Inc., Spartanburg, SC. The test uses a flow plate positioned above the test sample and below the Lister test device. A 5 ml volume of 0.9% saline solution is applied to the sample assembly.The time required to absorb the liquid (transit time) is automatically measured and displayed by the Lister test device. A new 5-ply blotting paper assembly is then quickly placed under the nonwoven sample within 20 seconds, and the 5 ml of saline solution is dispensed again. A total of 5 ml of liquid is dispensed 5 times on the selected nonwoven sample, and each transit time is recorded. The sample is reweighed after the sequence of 5 tests. For a given nonwoven sample, the 5-sequence test is repeated 5 times, and the results are averaged to determine the transit time of the material. Draping coefficient test

[0104] The Cusick drape test can be performed using any suitable drape test device to obtain a drape coefficient. Commercially available drape test devices include the TF118 test device marketed by Testex of Dongguam, China, or the Model 665 test device marketed by James H Heal & Co. of Halifax, England. The drape test can be performed according to ISO Test 9073-9 (2008). Martindale Abrasion:

[0105] This test measures the relative abrasion resistance of a specimen according to Worldwide Strategic Partners (“WSP”) Standard Test No. 20.5 (08). A circular specimen with a diameter of 165 mm ± 6.4 mm and an area of ​​18,258 mm 2is subjected to a required number of cycles (10 or 60) with an abrasive under a pressure of 9 kilopascals (kPa). The abrasive is a 36 inch by 4 inch by 0.05 thick, glass fiber reinforced silicone rubber wheel with a rubber surface hardness of 81A Durometer, Shore A of 81±9. The specimen is examined for the presence of surface fraying (fiber abrasion), pilling (small fiber remnants), roping, delamination, or holes and assigned a numerical rating of 1, 2, 3, 4, or 5 based on comparison with a set of similarly numbered standard photographs, with "1" indicating the greatest wear and "5" the least. The test is conducted using a Martindale Wear and Abrasion Tester, such as Model No. 103 or 403 from James H. Heal & Company, Ltd. of West Yorkshire, England. Surface roughness

[0106] Topographic maps of the surface of each spunbond sample (10 mm x 10 mm sections of each sample) were created using a confocal microscope (Keyence VK-X160K 3D laser confocal microscope using the VKViewer software supplied by Keyence with the microscope). A background plane was subtracted from each map to flatten each map and correct for any tilt of the samples. Data analysis was performed using MultiFileAnalyze software provided by Keyence. The corrected maps were measured according to ISO method 25178 and surface roughness measurements were used to calculate the following: Sa - Average mean surface height (in micrometers) Sq - Root mean square (RMS) of surface height (in micrometers) Str - Surface Texture Ratio (expressed as a unitless value) - indicates the uniformity of the surface texture (Str ranges from 1 for an isotropic surface to 0 for an aligned surface (e.g., a brushed surface)) Sdr - Developed interfacial area ratio (expressed as a unitless value) which indicates the ratio of the area of ​​the surface to a flat surface of the same size (where Sdr = 0 indicates a completely flat surface, higher values ​​indicate a rougher surface. Profile elevation analysis: Two lines were drawn across each map, and the surface elevation profile along this line was extracted. The height between the lower section of the profile and the higher section of the profile was measured. Area step height analysis:

[0107] Keyence software was used to isolate the bottom 10% of each topographic map, and the average elevation of this area was calculated.

[0108] Keyence software was used to isolate the top 10% of each topographic map, and the average elevation of this area was calculated.

[0109] The difference between these two values ​​was calculated to indicate a “step height” between the low and high ranges of each card. Cradle test procedure:

[0110] The cradle test replicates the actual positioning of a garment on a wearer and can be used to determine the absorption rates, backflow, and liquid distribution of a garment. In this method, a slotted receiving device, as shown in Fig.4b and US Pat. No. 6,727,404, both of which are made of a water-resistant material, such as acrylic plastic, and simulate a wearer's body curvature.

[0111] The holder (for diapers, etc.) has a total length of 305 mm, a width of 350 mm in the slot direction, and a height of 255 mm (including 57 mm of height below the slot). The material used in the construction varies in thickness from 6 mm to 12 mm. The holder has a 6 mm wide slot at its deepest point, which runs the length of the holder. The curvature of the holder is formed by an angle of 60°. 1. Product preparation A. For adult hygiene clothing, the three-dimensional pants-like products are cut at the sides or side seams to make the product two-dimensional. B. Do not cut leg and flap elastic. C. Weigh the product to the nearest 0.01 gram and record the value. D. Measure the cushion length (using a light board) to the nearest millimeter and note the value. E. Measure the product length and mark the center. F. Mark the insult area at a distance from the center of the product to the nearest 1 mm. Center the measurement in the transverse direction. The marked distance depends on the product being tested as follows: Diaper Size Weight Range (lb) Distance (cm) < 10 < 14 12-18 16-28 22-37 > 27 > 35 Unisex 4 5,5 6,5 7.5 8,5 9 9,2 Boy 6 7,5 8,5 9,5 10,5 11 11,2 Girl 2 3,5 4,5 5,5 6,5 7 7,2 Diaper size (1b) Distance (cm) 18-34* 32-40* > 38* 38-65** 60-125** Unisex 8,5 9 9,5 12,0 - Boy 10,5 11 12 15 17 Girl 6,5 7 7 9 8 * Tracksuit pants ** Youth trousers 2. Product test (test liquid = 0.9 w / v% saline solution) A. Verify that the pump delivers the required test fluid volume for the insult + / - 0.5 ml. The flow rate should be set to 8 ml / second. The test fluid volume is 50 ml for adult care products or 85 ml for baby diapers. The tubing end or nozzle should have an outlet diameter of 0.125 inches. B. For the slotted containment device, place a catch basin of known weight under the containment device slot to collect any fluid overflow. Measure the weight of the catch basin to the nearest 0.01 gram. Note: Low-capacity products without flaps (i.e., cloth underwear, cloth training pants, vinyl / cloth training pants) are prone to overflow. C. Position the specimen with the insert / inside facing up, with the "pre-marked" center of the product aligned with and touching the lowest point in the cradle. The entire length of the outer shell / outer surface of the product should be in contact with the cradle. Clamp or otherwise secure the product to the cradle at the front and back waist edges to hold it in place. Gently pull on the front / back waist of the specimen to smooth out any wrinkles or creases in the product. For the cradle test, all product codes are insulated at a point 95 mm in front of the center of the product. D. Hold the nozzle above the target area and perpendicular to the sample. The base of the nozzle should be 5 to 10 mm from the sample. E. Begin the insult and start the stopwatch when the test fluid exits the nozzle. Once the insult is complete, move the nozzle to the side to observe the test fluid. F. Stop the stopwatch immediately when the test fluid is no longer visible on the sample surface. Record the exposure time to the nearest 0.01 second. If the fluid overflows into the collection container, the exposure time is recorded as soon as no more fluid is visible on the surface. G. After the insult has been absorbed, immediately set the timer for 15 minutes. Keep the subject in the holding device during the entire waiting period. H. Repeat steps D to G two more times for a total of 3 insults separated by 15 minutes. I. For the reflux test, after completing the final insult and recording the absorption time, set the timer for 2 minutes. Reflux is the amount of unabsorbed fluid after the third insult. More specifically, it is defined as the amount of fluid that can be absorbed by an insulted sample onto a blotting paper when subjected to a predetermined vacuum pressure for a specified period of time. J. At the end of the waiting period, immediately transfer the specimen from the receiving device to a saturation capacity tester, as described and illustrated in U.S. Patent No. 6,727,404, which is hereby incorporated by reference. Hold the specimen in the receiving device during the transfer and then place it flat (horizontally) on the saturation capacity tester with the insert / inside facing up. Center the specimen on the saturation capacity tester. Hold the test specimen flat and place either one pre-weighed 228 mm x 300 mm (plus or minus 13 mm) blotting paper or two pre-weighed 88 mm x 300 mm (plus or minus 13 mm) blotting papers on the absorbent side of the specimen. The blotting paper has a basis weight of 300 g / m 2 - VERIGOOD Grade 88. Place blotting paper(s) approximately 6 mm from the front end fluff of the test piece. K. Cover the test specimen and the blotting papers with a latex rubber sheet as described in U.S. Patent No. 6,727,404 and press the start button on the vacuum control housing. L. Maintain 0.5 + / - 0.04 psi on the saturation capacity tester for 2 minutes. After the time has elapsed, lift the latex rubber sheet to release the pressure from the saturation capacity tester. M. Immediately remove the blotting papers, weigh them to the nearest 0.01 gram, and record the reflux value. The reflux is determined from the weight of the blotting paper(s): (wet weight - dry weight) / dry weight). EXAMPLE 1

[0112] Nonwoven webs were prepared according to the present disclosure as shown in Table 1: Table 1 Component A Component B sample A / B ratio A B C D A B C D E F Control 1 70 / 30 79 % 10 % 10 % 1 % 89 % 10 % 0% 1 % 0% 0% Control 2 and 3 50 / 50 83 % 6% 10 % 1 % 0% 10 % 0% 0% 0% 90 % Sample 1 70 / 30 79 % 10 % 10 % 1 % 59 % 10 % 0% 1 % 30 % 0% A: Polypropylene homopolymer, available for example as 3155 from ExxonMobil B: Masterbatch of 12.5 wt% modified siloxane in polypropylene, available, for example, as a blend of Masil SF-19 and Exxon 3155 from Americhem C: Propylene-ethylene copolymer-based plastomer with 14% ethylene from ExxonMobil Chemical Co., available under the name VistaMaxx 7050 D: 50 wt% titanium dioxide particles in a polypropylene carrier resin, available, for example, from Standridge Color Corporation E: Rapid crystallization additive, polypropylene homopolymer, available, for example, as Achieve™ Advanced PP 3684 from ExxonMobil F: Polyethylene plastomer, available for example as Aspun 6840A from Dow Chemicals

[0113] The nonwoven webs were formed into inserts as described above and subjected to various tests as shown in Table 2: Table 2: binding Thickness / Basis weight Basis weight (g / m 2 ) TSA TS7 TSA TS750 TSA D-Stiffness Draping (cm) Lister (s) Sample 1 Point 0,018 37,9 2,2 4 3,3 2,8 11,8 Control 1 Point 0,014 35,2 2,6 5,3 2,1 4,4 21,2 Control 2 TAB 0,017 32,5 3,3 3,8 3,1 3,6 4,8 Control 3 Point 0,022 34,5 4,6 4,7 4,4 2,3 4,7 Table 2 (continued) Train peak load (MD, lbf) Elastic modulus (psi) Air permeability (ft 3 / ft 2 / min) Total energy of shell deformation (N-mm) Shell deformation peak load (gf) Martindale Thickness (mm) Peak energy (in *lbf) Sample 1 8,55 457 537 2,75 21,35 4 0,66 3,2 Control 1 13,14 4027 464 7,63 49,41 1,5 0,48 9,4 Control 2 4,26 885 871 3,61 25,08 1,9 0,56 4,1 Control 3 4,44 217 789 0,98 8,69 1,5 0,76 16,3

[0114] The nonwoven webs were also formed into inserts and placed over a surge layer and subjected to various tests as shown in Tables 3 to 5. In addition, Fig. 3A to 3D SEM images are shown, showing the curl and irregularity of each code.

[0115] Absorbent articles were made from the insert and surge layer. The absorbent articles were tested for absorbency in Tables 3 and 4 below. In each example, the absorbent article contained an 80 g / m 2 Nonwoven absorbent structure with super absorbent particles and a 74 mm x 178 mm surge layer.

[0116] Table 3 shows the results of the cradle test as described above. Table 3 1. Recording(s) 2. Recording(s) 2. Recording(s) Return flow (%) Sample 1 7,4 10 48 24,8 Control 1 7,9 11 63 25,1 Control 2 7,3 10 76 26,2

[0117] Table 4 shows the results of a stool (BM) drainage test using a simulated BM. Table 4 RBM discharge (g) RBM max. MD length (mm) RBM max. CD width (mm) Sample 1 0,6 251 30 Control 1 1,1 251 28 Control 2 0 212 31

[0118] As illustrated by the results in Tables 2 to 4, the nonwoven webs according to the present disclosure exhibited excellent absorbency and softness with good stiffness and abrasion resistance.

[0119] The nonwoven web interlinings formed from Sample 1 and Control 1 were subjected to a surface roughness test as previously discussed, the results of which are illustrated in Table 5. As shown, Sample 1 exhibited improved surface roughness across all measurements than Control 1, which is also illustrated in the cross-sectional SEM images of Figures 4A and 4B (SEM images of the samples prior to formation into an interlining). Table 5 insert Sa. (µm) Sq. (µm) Street . Sdr . Profile height (µm) Δ Step height Sample 1 81 103 0,76 7,4 397 339 Control 1 75 97 0,31 7 321 321

[0120] The samples were also subjected to micro-CT and image analysis to determine the percentage porosity and projection height. A Bruker SKYSCAN 1272 micro-CT was used to examine the samples X-ray under the following conditions: Source voltage = 30 kV Source current = 133 µA Image pixel size = 10.0 µm Exposure = 220 ms Rotation step = 0.2° Image averaging = ON (6) Random Move = ON (1)

[0121] NRECON software was used to reconstruct the X-ray images into cross-sectional sections. DATA VIEWER software was then used to extract at least five transaxial view images per code. These images were then analyzed using the "Z-Projection Height (Micro-CT Slices)-1" image analysis algorithm to obtain the results presented below. At least 12 measurements were taken per code. CTAn software was used to capture the 3D micro-CT results. The following results were obtained: Table 6 % Porosity % object volume Object surface / volume Projection height (mm) Sample 1 85,6 14,4 116,1 0,48 Control 1 74,6 25,4 113,1 0,3 Control 2 77,4 22,6 107,9 0,43 Control 3 83,2 16,8 112,5 0,44

[0122] These and other modifications and variations of the present disclosure may be implemented by those of ordinary skill in the art without departing from the spirit and scope of the present invention, as particularly pointed out in the appended claims. Furthermore, it is to be understood that aspects of the various embodiments are interchangeable, in whole or in part.

[0123] Furthermore, those of ordinary skill in the art will understand that the foregoing description is exemplary only and is not intended to limit the invention as particularly described in the appended claims. QUOTES CONTAINED IN THE DESCRIPTION

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[0094] US 4,886,512

[0094] US 6,727,404 [0110, 0111] Zitierte Nicht-Patentliteratur

[0000] Ewen et al., 5,218,071 an Tsutsui et al., 5,272,236 an Lai et al. und 5,278,272 an Lai

[0059] Datta, et al.; 5,539,056 an Yang

[0061] McAlp

[0068] 322,728 an Davis et al., 5,472,775 an Obiieski

[0068] ISO Test 9073-9 (2008

[0104]

Claims

[1] Nonwoven web, comprising: a multi-component fiber, the multi-component fiber comprising: a first polymer-containing component and a second polymer-containing component, wherein the second polymer-containing component comprises a rapid crystallization additive and has a solidification and / or crystallization rate that is at least about 10% or more than a solidification and / or crystallization rate of the first polymer-containing component, and wherein the first polymer component and / or the second polymer component comprises one or more polymers having a melting temperature of at least about 130°C or more; wherein the nonwoven web has a TS7 softness value of about 6 or less as measured by an EMTEC Tissue Softness Analyzer (“TSA”) output. [2] The nonwoven web of claim 1, wherein the nonwoven web has a thickness of about 0.5 mm or more. [3] Nonwoven web according to claim 1 or 2, wherein the nonwoven web has a thickness normalized to the basis weight of about 0.015 mm per g / m 2 (grams per square meter) or more. [4] Nonwoven web according to one of claims 1 to 3, wherein the nonwoven web has a density of about 76 kg / m 3 or less and / or wherein the nonwoven web has a TSA stiffness of about 3.25 mm / N or less. [5] The nonwoven web of any one of claims 1 to 4, wherein at least one of the first polymer-containing component and the second polymer-containing component comprises more than about 90 wt.% polypropylene, based on the weight of the respective component. [6] The nonwoven web of any one of claims 1 to 5, wherein the multicomponent fiber comprises more than about 70% by weight of polypropylene based on the weight of the fiber. [7] The nonwoven web of any one of claims 1 to 6, wherein the nonwoven web has a tensile peak load of about 4.5 lbf or more. [8] A nonwoven web according to any one of claims 1 to 7, wherein the rapid crystallization additive is present in the second polymer-containing component in an amount of about 5 wt% to about 50 wt%, preferably about 20 wt% to about 30 wt%, based on the weight of the second polymer-containing component. [9] The nonwoven web of any one of claims 1 to 8, wherein the multicomponent fiber has an average of at least about 8 crimps per cm and a denier of about 5 or less. [10] The nonwoven web of any one of claims 1 to 9, wherein the rapid crystallization additive has a melt flow rate (MFR) of between about 81 g / 10 min and about 50 g / 10 min, measured at a temperature of 230°C and a load of 2.16 kg, determined according to ASTM D1238. [11] Nonwoven web according to one of claims 1 to 10, wherein the additive for rapid crystallization is a polypropylene polymer, preferably a polypropylene homopolymer. [12] The nonwoven web of any one of claims 1 to 11, wherein at least one of the first polymer-containing component and the second polymer-containing component comprises 50% by weight or more, preferably from about 90% by weight to about 100% by weight, based on the total weight of the polymer in the respective polymer-containing component, of a polymer having a melting temperature of about 130°C or more, preferably wherein at least one of the first polymer-containing component and the second polymer-containing component is generally free of polyethylene polymers or copolymers. [13] The nonwoven web of any one of claims 1 to 12, wherein the first polymer component and / or the second polymer component comprises one or more polymers having a melting temperature of at least about 150°C or more. [14] An absorbent article comprising the nonwoven web according to any one of claims 1 to 13. [15] A method of forming a nonwoven web comprising: Spinning a fiber having at least a first polymer-containing component and a second polymer-containing component, wherein the second polymer-containing component comprises a rapid crystallization additive and has a solidification and / or crystallization rate that is at least about 10% or more than a solidification and / or crystallization rate of the first polymer-containing component; pulling the fibers; depositing the fibers on a forming surface; and Subjecting the fibers to a high-temperature bonding treatment of about 130 °C or more. [16] The method of claim 15, wherein at least one of the first polymer-containing component and the second polymer-containing component comprises more than about 90 wt.% polypropylene, based on the weight of the respective component. [17] The method of claim 15 or 16, wherein the fibers comprise more than about 70% by weight of polypropylene based on the weight of the fiber. [18] A method according to any one of claims 15 to 17, wherein the fibers comprise more than about 90% by weight of polypropylene based on the total weight of the polymers present in the fiber. [19] A process according to any one of claims 15 to 18, wherein the multicomponent filaments are continuous or discontinuous. [20] A method according to any one of claims 15 to 19, wherein the fibers have on average at least about two crimps per cm without heat treatment. [21] The method of any one of claims 15 to 20, wherein the high temperature bonding treatment is a thermal point bond and / or wherein the nonwoven web has a total bond area of about 30% or less.

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