Nonwoven fabric with improved flexibility

Abstract

A nonwoven fabric having a plurality of fibers bonded together to form a coherent web, wherein the plurality of fibers comprise the formation of a polymer blend of a polypropylene resin and an elastomerous polyolefin, wherein the nonwoven fabric exhibits a reduction in fiber fineness of at least 5% compared to a nonwoven fabric prepared under the same conditions without the elastomerous polyolefin blended with the polypropylene resin.

Description

[Technical Field]

[0001] Cross-reference with related applications This application claims priority to U.S. Provisional Application No. 63 / 521,466, filed on 16 June 2023, the contents of which are incorporated herein by reference.

[0002] [Technical field] This invention generally relates to nonwoven fabrics, and more particularly to bonded nonwoven fabrics that exhibit improvements in fiber fineness and softness. [Background technology]

[0003] Nonwoven fabrics are used in a variety of applications, particularly in garments, disposable medical products, and absorbent articles such as diapers and personal hygiene products. New products developed for these applications require stringent performance requirements, including comfort, conformity to the body, freedom of movement, good flexibility and drape, sufficient tensile strength and durability, and resistance to surface abrasion and pilling. Therefore, nonwoven fabrics used in these types of products must be designed to meet these performance requirements. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Despite the considerable effort put into developing nonwoven fabrics, there remains a need for products that demonstrate improvements in flexibility and fiber fineness without sacrificing other beneficial properties, such as mechanical properties. [Means for solving the problem]

[0005] One or more embodiments of the present invention can be to provide a nonwoven fabric having desirable properties with respect to fiber fineness and flexibility while maintaining good mechanical properties such as tensile strengths and elongations.

[0006] One embodiment is directed to a nonwoven fabric including a plurality of fibers adhered on its surface with a bond pattern to form a coherent web.

[0007] In one embodiment, a nonwoven fabric is provided where a plurality of fibers adhere to form a coherent web, and the plurality of fibers includes a polymer blend of a polypropylene resin and an elastomeric polyolefin, wherein the nonwoven fabric exhibits at least a 5% reduction in fiber fineness compared to a similarly manufactured nonwoven fabric that does not include the elastomeric polyolefin blended with the polypropylene resin.

[0008] In one embodiment, the polypropylene resin has a molecular weight in any range of 120,000 g / mol to 300,000 g / mol, 140,000 g / mol to about 280,000 g / mol, about 150,000 g / mol to about 250,000 g / mol, particularly about 160,000 g / mol to about 180,000 g / mol. In some embodiments, the polypropylene resin includes Ziegler-Natta catalyzed polypropylene, metallocene catalyzed polypropylene or a blend thereof.

[0009] In certain embodiments, the plurality of fibers are bicomponent fibers having a sheath core configuration where the elastomeric polyolefin is present only in either the sheath or the core. In other embodiments, the elastomeric polyolefin may be present in both the sheath and the core.

[0010] In certain embodiments, the polypropylene resin of the blend has a melting point of about 150°C to about 175°C. In certain embodiments, the polypropylene resin is present in the polymer blend in an amount of about 75 to about 99 weight percent, particularly about 80 to about 95 weight percent, more particularly about 85 to about 94 weight percent, based on the total weight of the polymer blend.

[0011] In certain embodiments, the elastomeric polyolefin is present in the polymer blend in an amount ranging from about 2 to about 30 weight percent, particularly 5 to 25 weight percent, more particularly about 8 to about 20 weight percent, based on the total weight of the polymer blend.

[0012] In certain embodiments, the elastomeric polyolefin comprises a propylene-alpha-olefin copolymer.

[0013] In certain embodiments, the elastomeric polyolefin comprises a low isotacticity polypropylene polymer.

[0014] In certain embodiments, the low isotacticity polypropylene has an isotacticity [mmmm] in the range of about 20 to about 70 mol%, particularly in the range of 30 to 60 mol%, more particularly in the range of 35 to 55 mol%.

[0015] In certain embodiments, the low isotacticity polypropylene has the following properties: Isotacticity: Mesopentad fraction of 20-70 mol% [mmmm]; Number-average molecular weight (Mw) between 10,000 and 200,000; A melting point of approximately 60 to 120°C; and, Melt flow rate (MFR) exceeding 40g / 10 minutes.

[0016] In one embodiment, the nonwoven fabric comprises fibers having an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and particularly about 1.2 to about 1.35 dtex.

[0017] In one embodiment, the nonwoven fabric exhibits a fiber dtex percentage reduction of approximately 5 to 30% compared to a nonwoven fabric prepared under identical conditions, except that it does not contain elastomer polyolefins and is drawn and attenuated at a cabin pressure of less than 4,200 Pa.

[0018] In one embodiment, the nonwoven fabric exhibits a fiber dtex percentage reduction of approximately 5 to 60% compared to a nonwoven fabric prepared under identical conditions, except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0019] In one embodiment, the nonwoven fabric exhibits a reduction in fiber dtex percentage of approximately 5 to 60%, for example, a reduction in fiber dtex percentage of 15 to 50%, a reduction in fiber dtex percentage of 10 to 30%, or a reduction in fiber dtex percentage of 15 to 25%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0020] In one embodiment, the nonwoven fabric has machine direction bending softness in the range of 30 to 50 mm and cross direction bending softness in the range of 15 to 40 mm.

[0021] In one embodiment, the nonwoven fabric has an average mechanical / transverse bending flexibility in the range of 20 to 45 mm, particularly about 25 to about 40 mm, and particularly about 28 to about 38 mm.

[0022] In one embodiment, the nonwoven fabric exhibits a percentage reduction in mechanical bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0023] In one embodiment, the nonwoven fabric exhibits a percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomeric polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0024] In one embodiment, the nonwoven fabric exhibits one or more of the following characteristics: a) Average fiber fineness in the range of approximately 0.8 to 1.6 dtex, particularly approximately 0.9 to 1.4 dtex, and more particularly approximately 1.2 to 1.35 dtex; b) The nonwoven fabric exhibits a percentage reduction of approximately 5 to approximately 60% in fiber dtex, for example, 15 to 25% in fiber dtex, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa; c) The nonwoven fabric exhibits mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm; d) The nonwoven fabric exhibits one or more machine-direction flexibility of less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more transverse flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm; e) exhibiting at least one mechanical directional flexibility of at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm and at least 48 mm, and at least one lateral flexibility of at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm and at least 46 mm; f) Average mechanical direction / lateral bending flexibility in the range of 25-40 mm, particularly about 28-38 mm, and at least one of the following average mechanical direction / lateral bending flexibility: at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / lateral bending flexibility is less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm; g) A percentage reduction in mechanical directional bending flexibility of about 20-40%, particularly about 25-35%, and more particularly about 26-32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; h) An average percentage reduction in mechanical / transverse bending flexibility of about 20-40%, particularly about 20-35%, and more particularly about 22-30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; i) An average percentage reduction in mechanical / transverse bending flexibility of at least one of the following: at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; j) An average percentage reduction in mechanical / transverse bending flexibility of less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and finely divided at a cabin pressure of less than 4,200 Pa; k) An increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; and, l) An increase in elongation percentage in one or more of the machine direction or transverse direction, ranging from about 5 to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0025] In one embodiment, the nonwoven fabric has an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly in the range of about 0.9 to about 1.4 dtex, and more particularly in the range of about 1.2 to about 1.35 dtex.

[0026] In one embodiment, the nonwoven fabric has a percentage reduction in fiber dtex of about 5 to about 30%, for example, a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0027] In one embodiment, the nonwoven fabric has mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility of 15 to 40 mm.

[0028] In one embodiment, the nonwoven fabric has mechanical direction flexibility of one or more of the following: less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and transverse direction flexibility of one or more of the following: less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm.

[0029] In one embodiment, the nonwoven fabric has mechanical bending flexibility of at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, at least 40%, at least 42%, at least 46%, and at least 48%, and transverse flexibility of at least 20%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, at least 40%, at least 42%, at least 46%, at least 48%, and at least 50 mm.

[0030] In one embodiment, the nonwoven fabric has an average machine direction / transverse bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm, for example, an average machine direction / transverse bending flexibility of at least one of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, and an average machine direction / transverse bending flexibility of at least one of at least 40 mm, at least 38 mm, at least 36 mm, at least 34 mm, at least 32 mm, at least 30 mm, at least 28 mm, at least 26 mm, at least 24 mm, at least 22 mm and at least 20 mm.

[0031] In one embodiment, the nonwoven fabric has a percentage reduction in mechanical bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0032] In one embodiment, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0033] In one embodiment, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40% compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0034] In one embodiment, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of one or more of the following: less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0035] In one embodiment, the nonwoven fabric has an increase in MD tensile strength and CD tensile strength ranging from about 2% to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0036] In one embodiment, the nonwoven fabric has an increase in elongation percentage in either the machine direction or the transverse direction ranging from about 5% to about 30% compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomeric polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0037] In one embodiment, the nonwoven fabric has the following characteristics: The average fiber fineness ranges from approximately 0.8 to 1.6 dtex, particularly 0.9 to 1.4 dtex, and more specifically 1.2 to 1.35 dtex; Compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa, the nonwoven fabric exhibits a percentage reduction of approximately 5 to approximately 60% in fiber dtex, for example, a percentage reduction of 15 to 25% in fiber dtex; and, The nonwoven fabric exhibits mechanical bending flexibility in the range of 30-50 mm and transverse bending flexibility in the range of 15-40 mm, for example, mechanical bending flexibility in the range of 35-45 mm and transverse bending flexibility in the range of 25-40 mm.

[0038] In one embodiment, the nonwoven fabric includes a spunbond layer.

[0039] In one embodiment, the nonwoven fabric comprises a first spunbond layer having low crimping filaments or no crimping filaments, and a second layer having crimped filaments.

[0040] In one embodiment, the nonwoven fabric comprises at least two layers, one of which is selected from the group consisting of a meltblown layer, a carded fabric layer, a spunbond layer, a resin-bonded layer, an airlaid fabric layer, and a spunlace layer.

[0041] In one embodiment, the nonwoven fabric is an absorbent article.

[0042] In a further view, embodiments of the present invention provide nonwoven fabric products including nonwoven fabrics according to embodiments of the present invention.

[0043] In one embodiment, the composite sheet material comprises a sheet material comprising one or more nonwoven layers, such as a meltblown layer, which include a nonwoven fabric according to an embodiment of the present invention. The sheet material comprises a meltblown layer.

[0044] In one embodiment, the composite sheet material includes one or more meltblown layers sandwiched between two spunbond layers.

[0045] A certain viewpoint is directed toward absorbent articles comprising a nonwoven fabric according to one or more embodiments of the present invention.

[0046] Another aspect of the present invention is, A first polypropylene resin and an elastomeric polyolefin are melt-mixed to form a molten or semi-molten polymer flow of the polymer blend; Introducing the polymer flow into a spinning beam; The polymer flow is extruded from the spinning beam to form fibers; The formed fibers are subjected to a cabin pressure exceeding 4,200 Pa to stretch and thin them; and, The method involves gathering the fibers on a collection surface to form a nonwoven web, wherein the plurality of fibers exhibit an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex, and the nonwoven shows a percentage reduction in fiber dtex of about 5 to about 30%, for example, a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven prepared under identical conditions except that it does not contain the elastomeric polyolefin and the fibers are stretched and finened at a cabin pressure of less than 4,200 Pa. This invention relates to a method for preparing adhesive nonwoven fabrics, including [specific components / materials].

[0047] In one embodiment, the cabin pressure is in the range of approximately 4,500 to approximately 7,500 Pa, for example, 4,800 to 7,500 Pa, 5,000 to 6,000 Pa, and 5,100 to 5,600 Pa.

[0048] In one embodiment, the blend and its components conform to the composition described above.

[0049] The nonwoven fabric and associated methods are also directed toward their use in preparing absorbent articles.

[0050] In a further view, the method also includes the step of depositing a second fabric layer on top of the nonwoven web. In one embodiment, the second fabric layer is selected from the group consisting of a meltblown layer, a carded nonwoven layer, a spunbond layer, a resin-bonded layer, an airlaid nonwoven layer, and a spunlace layer.

[0051] In one embodiment, the method further includes a step of thermal bonding the nonwoven web.

[0052] In one embodiment, the process of heat-bonding the nonwoven web includes calender bonding the nonwoven web using an engraved roll having raised bonding points configured and arranged to impart a bonding pattern to the surface of the nonwoven web, wherein the bonding pattern comprises a percentage of bonding area of ​​about 9.6 to about 14% and a thickness of about 0.10 to about 0.25 mm. 2 The average of the individual bond surface areas, and approximately 4 to 7.25 mm. -1 It has an average bond point packing value.

[0053] The present invention has been described in general terms, but hereby refer to the attached drawings, which are not necessarily drawn to scale. [Brief explanation of the drawing]

[0054] [Figure 1] Figure 1 shows a nonwoven fabric according to at least one embodiment of the present invention. [Figure 2] Figure 2 shows a system for preparing a nonwoven fabric according to at least one embodiment of the present invention. [Figure 3] Figure 3 shows a system for preparing a nonwoven fabric according to at least one embodiment of the present invention; [Figure 4A] Figure 4A shows a multilayer nonwoven fabric according to at least one embodiment of the present invention. [Figure 4B] Figure 4B shows a multilayer nonwoven fabric according to at least one embodiment of the present invention. [Figure 4C] Figure 4C shows a multilayer nonwoven fabric according to at least one embodiment of the present invention. [Figure 4D] Figure 4D shows a multilayer nonwoven fabric according to at least one embodiment of the present invention. [Figure 5] Figure 5 shows a typical adhesion pattern used in point bonding nonwoven fabrics according to an embodiment of the present invention. [Modes for carrying out the invention]

[0055] With reference here to the accompanying drawings which show some but not all embodiments of the present invention, the present invention is described more fully below. In fact, the present invention may be carried out in many different forms and should not be construed as being limited to the embodiments shown herein, but rather these embodiments are provided to satisfy the legal requirements to which this disclosure is applicable. Similar numbers throughout refer to similar elements. Where used herein and in the appended claims, the singular “one” (a or an) and “the” include plural references unless the context clearly states otherwise.

[0056] The words “first” and “second,” as well as “primary,” “exemplary,” and “secondary,” do not indicate order, quantity, or importance, but are used to distinguish one element from another. Furthermore, the words “a” and “an,” and the word “the,” do not indicate a limitation of quantity, but rather indicate that there is “at least one” item being referred to.

[0057] Each embodiment disclosed herein is intended to be applicable to each of the other disclosed embodiments. All combinations and subcombinations of the various elements described herein are within the scope of the present invention.

[0058] If a parameter range is provided, it is understood that all integers within that range, as well as one-tenth and one-hundredth thereof, are also provided by the present invention. For example, "5-10%" includes 5%, 6%, 7%, 8%, 9%, and 10%; 5.0%, 5.1%, 5.2%....9.8%, 9.9%, and 10.0%; and 5.00%, 5.01%, 5.02%....9.98%, 9.99%, and 10.00%.

[0059] As used herein, the words “about,” “approximately,” and “substantially” mean, in the context of numbers or ranges, ±10% of the stated or claimed number or range, and in particular, include values ​​within the standard margin of error of measurement (e.g., SEM) of the stated value, or variations of ±0.5%, ±1%, ±5%, or ±10% from the specified value.

[0060] For the purposes of this application, the following terms shall have the meanings set forth below.

[0061] The word "fiber" can refer to a fiber of finite length, or a filament of infinite length.

[0062] As used herein, the term "monocomponent" refers to a fiber formed from one polymer, or a fiber formed from a single blend of polymers. Of course, this does not exclude fibers to which additives have been added for purposes such as color, antistatic properties, lubricity, hydrophilicity, or quenchability.

[0063] As used herein, the term “multicomponent” means a fiber formed from at least two polymers (e.g., a two-component fiber) extruded from separate extruders. The at least two polymers may be the same as or different from each other independently, or they may be a blend of polymers. The polymers are arranged in individual zones that are substantially evenly spaced across the cross-section of the fiber. The components may be arranged in any desired configuration, e.g., sheath-core, side-by-side, pie, island-in-the-sea, etc. Various methods for forming multi-component fibers are described in U.S. Patent No. 4,789,592 for Taniguchi et al., U.S. Patent No. 5,336,552 for Strack et al., U.S. Patent No. 5,108,820 for Kaneko et al., U.S. Patent No. 4,795,668 for Kruege et al., U.S. Patent No. 5,382,400 for Pike et al., U.S. Patent No. 5,336,552 for Strack et al., and U.S. Patent No. 6,200,669 for Marmon et al., and these are incorporated herein by reference in their entirety. Multi-component fibers having various irregular shapes are also described, for example, in U.S. Patent No. 5,277,976 for Hogle et al., U.S. Patent No. 5,162,074 for Hills, U.S. Patent No. 5,466,410 for Hills, U.S. Patent No. 5,069,970 for Largman et al., and U.S. Patent No. 5,057,368 for Largman et al., and these are incorporated herein by reference in their entirety.

[0064] As used herein, the terms “nonwoven,” “nonwoven web,” and “nonwoven fabric” mean a structure or web of material formed without using a weaving or knitting process, which is intertwined but not in a recognizable, repeating manner. Nonwoven webs have historically been formed by various conventional processes, such as the meltblown process, the spunbond process, and the staple fiber carding process.

[0065] As used herein, the term “meltblown” refers to a process in which fibers are formed by extruding a molten thermoplastic material through a plurality of thin, usually circular, die capillaries into a high-speed gas (e.g., air) flow, the high-speed gas flow thins the molten thermoplastic material and forms fibers that may be up to the diameter of microfibers. The meltblown fibers are then carried by the gas flow and deposited on a collection surface to form a random web of meltblown fibers. Such a process is disclosed, for example, in U.S. Patent No. 3,849,241 to Buntin et al.

[0066] As used herein, the terms “machine direction” or “MD” refer to the direction of movement of the nonwoven web during manufacturing.

[0067] As used herein, the terms “cross direction” or “CD” mean the direction perpendicular to the machine direction and extending transversely within the width of the nonwoven web.

[0068] As used herein, the term “diagonal direction” or “DD” means a direction that is positioned at an angle greater than 0 degrees and less than 90 degrees with respect to one or more lateral and mechanical directions.

[0069] As used herein, unless otherwise specified, the term “molecular weight” (or “Mw”) means weight-average molecular weight, which is expressed in grams per mole. This weight-average molecular weight can be measured using common methods such as gel permeation chromatography or “GPC”.

[0070] As used herein, the term “spunbond” refers to the process of extruding a molten thermoplastic material as filaments from a plurality of thin, usually circular, capillaries of a spinneret, then thinning the filaments, and then stretching them mechanically or pneumatically. The filaments are deposited on a collection surface to form a web of substantially continuous filaments arranged randomly, which can then be bonded together to form a single nonwoven fabric. The manufacture of spunbond nonwoven webs is described in patents, for example, U.S. Patent No. 3,338,992; U.S. Patent No. 3,692,613; U.S. Patent No. 3,802,817; U.S. Patent No. 4,405,297; and U.S. Patent No. 5,665,300. Generally, these spunbond processes include extruding the filament from a spinneret, quenching the filament with an airflow to accelerate the solidification of the molten filament, thinning the filament by applying draw tension either by riding the filament in an airflow with air pressure or by winding the filament onto mechanical draw rolls, depositing the drawn filaments onto a foraminous collection surface to form a web, and bonding the web of loose filaments into a nonwoven fabric. The bonding can be any thermal or chemical bonding treatment, typically thermal point bonding.

[0071] As used herein, the term “thermal point bonding” includes passing a material to be bonded between a heated calender roll and an anvil roll, such as one or more webs. The calender roll is typically patterned so that the nonwoven fabric is bonded at individual point bonding sites rather than across its entire surface.

[0072] As used herein, the term “air-through thermal bonding” involves passing a material, such as one or more webs of fibers to be bonded, through a flow of a heated gas, such as air, where the temperature of the heated gas is higher than the softening or melting temperature of at least one polymer component of the material being bonded. Air-through thermal bonding may also involve passing the material through a heated oven.

[0073] As used herein, the term “bond density” means the number of individual bond points within a given surface area of ​​the nonwoven fabric.

[0074] As used herein, the term "polymer" generally includes, but is not limited to, homopolymers, copolymers, such as block copolymers, graft copolymers, random copolymers and alternating copolymers, terpolymers, and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term "polymer" encompasses all possible geometric configurations of materials, such as isotactic, syndiotactic and random symmetries.

[0075] Nonwoven fabric

[0076] One embodiment of the present invention provides a nonwoven fabric exhibiting improved flexibility and fiber fineness, wherein at least one portion of the fibers of the nonwoven fabric is directed to the nonwoven fabric comprising a polymer blend of a polypropylene polymer and an elastomeric polyolefin polymer. In one embodiment, the present invention provides a nonwoven fabric comprising a plurality of fibers, wherein the plurality of fibers comprise a blend of a first polypropylene polymer and at least one elastomeric polyolefin polymer. As described in more detail below, the inclusion of the elastomeric polyolefin polymer in the polymer blend improves the softness and fineness of the fibers of the nonwoven fabric compared to the same nonwoven fabric without the elastomeric polyolefin polymer.

[0077] Referring to Figure 1, a nonwoven fabric according to at least one embodiment of the present invention is shown, designated by reference numeral 10. The nonwoven fabric comprises a plurality of fibers 12 that associate with each other to form a coherent web. The nonwoven fabric comprises a first outer surface 14 and a second outer surface 16. In some embodiments, the plurality of fibers of the nonwoven fabric remain relatively unbonded without being subjected to further bonding processes.

[0078] To our advantage and surprise, the inventors of this disclosure have found that improvements in both flexibility and fiber fineness can be obtained in a nonwoven fabric in which a plurality of fibers comprise a polymer blend comprising a first polypropylene polymer and an elastomeric polyolefin polymer, and the plurality of fibers are spun under certain spinning parameters, which will be described in detail later.

[0079] First polypropylene polymer

[0080] In one embodiment, the first polypropylene polymer constitutes the remainder of the polymer blend and typically comprises a polypropylene polymer resin suitable for spinning continuous filaments in a spunbond process. In another embodiment, the first polypropylene polymer constitutes a trace component of the polymer blend, and the elastomeric polyolefin polymer constitutes the remainder of the polymer blend.

[0081] A wide variety of polypropylene polymers can be used in various embodiments of this disclosure. Examples of suitable polypropylenes that can be used typically have molecular weights greater than 120,000 g / mol, more typically 150,000 to about 300,000 g / mol. In one embodiment, the polypropylene polymer may have molecular weights in the range of about 150,000 to about 250,000 g / mol, and particularly about 160,000 to about 180,000 g / mol. In a certain embodiment, the polypropylene resin may have molecular weights in the range of 120,000 to 300,000 g / mol, about 140,000 g / mol to about 280,000 g / mol, about 150,000 to about 250,000 g / mol, and particularly about 160,000 to about 180,000 g / mol.

[0082] In one embodiment for the preparation of spunbond fibers, a suitable polypropylene resin typically has an MFR of about 10 to about 100 g / 10 min, particularly about 20 to about 40 g / 10 min, where an MFR of about 22 to about 38 g / 10 min is somewhat more typical. Unless otherwise specified, the MFR is measured according to ASTM D-1238.

[0083] In one embodiment, the polypropylene resin has a melting point of about 150°C to about 175°C, for example, a melting point in the range of about 150°C to about 160°C.

[0084] An example of such polypropylene is the product name Metocene HM562S (30 MFRg / 10 min, 0.90 g / cm³). 3Available from LyondellBasell under (density); Ziegler-Natta catalyzed homopolymer polypropylene available from IPRC Thailand under product number 1105SC (35 MFRg / 10 min); by ExxonMobil, e.g., PP3155 (36 MFRg / 10 min, 0.90 g / cm 3 density, and Mw 172 kg / mol); PP3155E5 (36 MFRg / 10 min, 0.90 g / cm 3 density, and Mw 172 kg / mol); and, ACHIEVE 商標 3854 (24 MFRg / 10 min, 0.90 g / cm 3 density) may be included. Polypropylene available from SABIC 登録商標 e.g., SABIC PP 511A (25 MFRg / 10 min, 0.905 g / cm 3 density), polypropylene available from Borealis, e.g., HG475FB (27 MFRg / 10 min) and polypropylene available from Braskem, e.g., CP360H (34 MFRg / 10 min) may be used.

[0085] The amount of the first polypropylene polymer in the polymer blend is typically, based on the total weight of the polymer blend, about 1 to about 99 weight percent, particularly about 5 to about 95 weight percent, more particularly about 10 to about 90 weight percent, and even more particularly about 15 to about 85 weight percent, of the polymer blend.

[0086] In one embodiment, the amount of the first polypropylene constitutes about 50 to about 99 weight percent of the polymer blend, based on the total weight of the polymer blend. In one preferred embodiment, the first polypropylene polymer constitutes the remainder of the polymer blend and thus exists in an amount greater than 50 weight percent based on the total weight of the blend. For example, the amount of the first polypropylene resin may be about 65 to about 99 weight percent, particularly about 70 to about 95 weight percent, and more particularly about 75 to about 90 weight percent, based on the total weight of the polymer blend.

[0087] In one embodiment, the amount of the first polypropylene polymer resin in the polymer blend is, based on the total weight of the polymer blend, at least 50 weight percent, at least 51 weight percent, at least 52 weight percent, at least 53 weight percent, at least 54 weight percent, at least 55 weight percent, at least 56 weight percent, at least 57 weight percent, at least 58 weight percent, at least 59 weight percent, at least 60 weight percent, at least 61 weight percent, at least 62 weight percent, at least 63 weight percent, at least 64 weight percent, at least 65 weight percent, at least 66 weight percent, at least 67 weight percent, at least 68 weight percent, at least 69 weight percent, at least 70 weight percent, at least 71 weight percent, at least 72 weight percent, and less It is at least 73% by weight, at least 74% by weight, at least 75% by weight, at least 76% by weight, at least 77% by weight, at least 78% by weight, at least 79% by weight, at least 80% by weight, at least 81% by weight, at least 82% by weight, at least 83% by weight, at least 84% by weight, at least 85% by weight, at least 86% by weight, at least 87% by weight, at least 88% by weight, at least 89% by weight, at least 90% by weight, at least 91% by weight, at least 92% by weight, at least 93% by weight, at least 94% by weight, at least 95% by weight, at least 96% by weight, at least 97% by weight, at least 98% by weight, and at least 99% by weight.

[0088] In one embodiment, the amount of the first polypropylene polymer in the polymer blend is less than 99% by weight, less than 98% by weight, less than 97% by weight, less than 96% by weight, less than 95% by weight, less than 94% by weight, less than 93% by weight, less than 92% by weight, less than 91% by weight, less than 90% by weight, less than 89% by weight, less than 88% by weight, less than 87% by weight, less than 86% by weight, less than 85% by weight, less than 84% by weight, less than 83% by weight, less than 82% by weight, less than 81% by weight, less than 80% by weight, less than 79% by weight, less than 78% by weight, and 7 These are less than 7% by weight, less than 76% by weight, less than 75% by weight, less than 74% by weight, less than 73% by weight, less than 72% by weight, less than 71% by weight, less than 70% by weight, less than 69% by weight, less than 68% by weight, 67% by weight, less than 66% by weight, less than 65% by weight, less than 64% by weight, less than 63% by weight, less than 62% by weight, less than 61% by weight, less than 60% by weight, less than 59% by weight, less than 58% by weight, less than 57% by weight, less than 56% by weight, less than 55% by weight, less than 54% by weight, less than 53% by weight, 52% by weight, and less than 51% by weight.

[0089] In one embodiment, the polypropylene resin is present in the polymer blend in an amount of about 75 to about 99 percent by weight, particularly about 80 to about 95 percent by weight, and more particularly about 85 to about 94 percent by weight, based on the total weight of the polymer blend.

[0090] It should also be recognized that the polymer blends according to embodiments of the present disclosure include, based on the total weight of the polymer blend, the content of the polypropylene polymer resin in any of the aforementioned weight percentages, for example, about 50 to about 99 weight percent, 60 to 98 weight percent, 67 to 97 weight percent, 68 to 96 weight percent, 69 to 96 weight percent, 70 to 95 weight percent, 71 to 94 weight percent, 72 to 93 weight percent, 73 to 92 weight percent, 74 to 91 weight percent, and 75 to 90 weight percent, as well as variations within these ranges.

[0091] In one embodiment, the first polypropylene polymer resin comprises metallocene-catalyzed polypropylene. In another embodiment, the first polypropylene polymer resin comprises Ziegler-Natta catalyzed polypropylene. In yet another embodiment, the first polypropylene polymer resin comprises a blend of metallocene-catalyzed polypropylene and Ziegler-Natta catalyzed polypropylene.

[0092] When present as a blend of metallocene-catalyzed polypropylene and Ziegler-Natta-catalyzed polypropylene, the ratio of metallocene-catalyzed polypropylene to Ziegler-Natta-catalyzed polypropylene is about 5:95 to about 95:5, particularly about 10:90 to about 90:10, and more particularly about 20:80 to about 80:20. In preferred embodiments, the ratio of metallocene-catalyzed polypropylene to Ziegler-Natta-catalyzed polypropylene is about 15:about 85, particularly about 25:about 75, more particularly about 30:about 70, and even more particularly 35:65.

[0093] In one embodiment, the first polypropylene polymer resin comprises metallocene-catalyzed polypropylene and Ziegler-Natta-catalyzed polypropylene, wherein the Ziegler-Natta-catalyzed polypropylene constitutes at least 50 weight percent of the polymer blend based on the total weight of the blend. For example, the amount of Ziegler-Natta-catalyzed polypropylene in the blend is at least about 50 weight percent, at least 52 weight percent, at least 54 weight percent, at least 56 weight percent, at least 58 weight percent, at least 60 weight percent, at least 60 weight percent, at least 62 weight percent, at least 64 weight percent, at least 66 weight percent, at least 68 weight percent, at least 70 weight percent, at least 72 weight percent, at least 74 weight percent, at least 76 weight percent, at least 78 weight percent, at least 80 weight percent, at least 82 weight percent, and at least 84 weight percent, based on the total weight of the polymer blend.

[0094] Elastomer polyolefin polymer

[0095] Suitable elastomeric polyolefins may include polymers having polyethylene, polypropylene, polybutylene, and other olefinic polymers, as well as blends thereof, provided that they possess elastomeric properties, such as extensibility and flexibility. These elastomeric polyolefin polymers may include both polyolefin homopolymers and polyolefin copolymers, as well as blends thereof.

[0096] In one embodiment, the elastomeric polyolefin polymer is present as a trace component in the polypropylene blend. In another embodiment, the elastomeric polyolefin polymer is present as a main component in the polymer blend.

[0097] The amount of the elastomeric polyolefin in the polymer blend is typically 1 to 99 weight percent based on the total weight of the fibers, and about 5 to about 95 weight percent, more particularly 10 to 90 weight percent, and even more particularly about 15 to about 85 weight percent, based on the total weight of the polymer blend.

[0098] In one embodiment, the amount of the elastomeric polyolefin in the polymer blend is typically 1 to 30 weight percent based on the total weight of the fibers, and more particularly about 5 to about 20 weight percent based on the total weight of the fibers. More particularly, the amount of the elastomeric polyolefin in the blend is about 1 to about 25 weight percent based on the total weight of the blend. More particularly, the amount of the elastomeric polyolefin may be about 2 to about 20 weight percent, for example about 4 to about 16 weight percent, about 5 to about 15 weight percent, or about 6 to about 14 weight percent based on the total weight of the blend.

[0099] In one embodiment, the elastomeric polyolefin is present in the polymer blend in an amount ranging from about 2 to about 30 weight percent, particularly 5 to 25 weight percent, and more particularly about 8 to about 20 weight percent, based on the total weight of the polymer blend.

[0100] In one embodiment of the present invention, the elastomeric polyolefin has a smaller molecular weight than the first polypropylene resin. For example, the molecular weight of the elastomeric polyolefin may be about 5 to about 35 percent lower than the molecular weight of the first polypropylene resin, for example, about 10 to about 25 percent lower, and particularly about 15 to about 20 percent lower.

[0101] A preferred example of an elastomeric polyolefin is a polymer in which propylene constitutes the main component of the polymer backbone, and as a result, the remaining crystallinity has the properties of polypropylene crystals. Persistent crystalline entities embedded within the propylene-based elastomer molecular network function as physical crosslinks, providing polymer chain fixation capabilities that improve the mechanical properties of the elastic network, such as high recovery, low set, and low force relaxation.

[0102] Suitable examples of elastomeric polyolefins may include elastomer random poly(propylene / olefin) copolymers, isotactic polypropylene with steric error, isotactic / atactic polypropylene block copolymers, isotactic polypropylene / random poly(propylene / olefin) copolymer block copolymers, stereoblock elastomeric polyolefins, syndiotactic polypropylene block poly(ethylene-co-propylene) block syndiotactic polypropylene triblock copolymers, isotactic polypropylene block regioirregular polypropylene block isotactic polypropylene triblock copolymers, polyethylene random (ethylene / olefin) copolymer block copolymers, reactor blend polypropylene, very low density polypropylene (or equivalent, ultra low density polypropylene), metallocene polypropylene, and combinations thereof.

[0103] In some embodiments, the elastomeric polyolefin encompasses polypropylene having both rigid and flexible segments, wherein the rigid segments are high crystallinity and the flexible segments are amorphous or semi-amorphous. For example, suitable elastomeric polyolefin polymers including crystalline isotactic blocks and amorphous atactic blocks are described, for example, in U.S. Patent Nos. 6,559,262, 6,518,378, and 6,169,151.

[0104] In one embodiment, the elastomeric polyolefin comprises an elastomeric random copolymer (RCP), which contains propylene and incorporates low levels of comonomers (e.g., ethylene or higher α-olefins) within its backbone. For example, the elastomeric polyolefin may include a propylene copolymer containing at least two different monomer units (one of which is propylene). Suitable examples of monomer units are, for example, ethylene and C4-C 20 The range of higher α-olefins includes, for example, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, or combinations thereof. Preferably, ethylene is copolymerized with propylene, so that the propylene copolymer contains propylene units (polymer chain units derived from propylene monomer) and ethylene units (polymer chain units derived from ethylene monomer).

[0105] Typically, the comonomer units of the propylene copolymer are derived from ethylene, or at least one C 4~10The alpha-olefin is present in an amount of 1% to 35% by weight or 5% to about 35% by weight of the propylene-alpha-olefin copolymer. It may be present in an amount of %, or 7% to 32% by weight, or 8% to about 25% by weight, or 8% to 20% by weight, or even 8% to 18% by weight. The comonomer content is such that the propylene-α-olefin copolymer preferably has an isothermal heat of fusion (DSC) of 75,000 Gy (75 J / g) or less, a melting point of 100°C or less, and a crystallinity of 2% to about 65%. In some embodiments, the polypropylene copolymer may contain tactic polypropylene and may be adjusted to have a melt flow rate of 0.5 to 90 dg / min.

[0106] In some embodiments, the elastomeric polyolefin comprises a propylene-α-olefin copolymer having ethylene-derived units. The propylene-α-olefin copolymer is 5% to 35% by weight, or 5% to 20% by weight, or 10% to 12% by weight, or 15% to 20% by weight of the propylene-α-olefin copolymer. It may contain a weight percentage of ethylene-derived units. In some embodiments, the propylene-α-olefin copolymer is essentially composed of propylene and ethylene-derived units, i.e., the propylene-α-olefin copolymer is ethylene and / or propylene used during polymerization.

[0107] In one embodiment, the propylene-α-olefin copolymer may have a triad tacticity of at least 75%, at least 80%, at least 82%, at least 85%, or at least 90% of three propylene units (measured by 13C NMR). The “triad tacticity” is determined as follows: The tacticity ratio (denoted herein as “m / r”) is determined by 13C nuclear magnetic resonance (“NMR”). The tacticity ratio m / r is calculated as defined in Cheng’s 17 MACROMOLECULES 1950 (1984), which is incorporated herein by reference. Here, the notation “m” or “r” represents the stereochemistry of an adjacent pair of propylene groups, where “m” means meso and “r” means racemic. A m / r ratio of 1.0 generally represents a syndiotactic polymer, and an m / r ratio of 2.0 generally represents an atactic material. Isotactic materials theoretically have an m / r ratio approaching infinity, and many by-product atactic polymers have a sufficient isotactic content to obtain an m / r ratio of over 50.

[0108] A suitable example of a propylene-α-olefin copolymer is VISTAMAXX 登録商標 (ExxonMobil Chemical Company, Houston, Tex., USA)VERSIFY 登録商標 (The Dow Chemical Company,Midland.Mich..USA), Grades of TAFMER 登録商標 XM or NOTIO 登録商標 (Mitsui Company, Japan) and Grades of SOFTEL 登録商標 This may include (Basell Polyfins of the Netherlands).

[0109] In one embodiment, the elastomeric polyolefin includes low isotactic homopolymer polypropylene (for example, polypropylene having an isotactic degree [mmmm] of 30 to 70 mol%).

[0110] Accordingly, in one embodiment, the elastomeric polyolefin may be present in amounts of about 1 to about 30 weight percent, 2 to 245 weight percent, 3 to 22 weight percent, 4 to 21 weight percent, 5 to 20 weight percent, 6 to 19 weight percent, 7 to 18 weight percent, 8 to 17 weight percent, 9 to 16 weight percent, and 10 to 15 weight percent, based on the total weight of the polymer blend.

[0111] The low-isotactic polypropylene can generally be characterized by one or more of the following properties: Isotacticity: 20-70 mol% mesopentad fraction [mmmm]; Number-average molecular weight (Mw) between 10,000 and 200,000; A melting point of approximately 60 to 120°C; and, Melt flow rate (MFR) exceeding 40g / 10 minutes.

[0112] In addition to the above characteristics, the low isotactic polypropylene may have a B viscosity of about 7,000 to about 400,000 mPa and a tensile modulus of about 80 to about 120 MPa.

[0113] Generally preferred low-isotactic polypropylene polymers have an isotactic degree of 20-70 mol% [mmmm], particularly 30-60 mol% [mmmm], and more particularly 35-55 mol% [mmmm]. In one embodiment, the low-isotactic polypropylene polymer has an isotactic degree of 40-50 mol% [mmmm] (mol%).

[0114] The stereochemistry of the low-isotactic polypropylene (e.g., stereoregularity index ([mm]), mesopentad fraction ([mmmm]), racemic pentad fraction ([rrrr]), racemic-meso-racemic-mesopentad fraction ([rmrm]), and triad fractions ([mm], [rr], and [mr])) is determined according to the peak assignments proposed by A. Zambelli, et al., Macromolecules, No. 8, p. 687 (1975). 13 It can be determined by 13C-NMR spectroscopy. 13 A 1C-NMR spectrometer, Model JNM-EX400 (manufactured by JEOL Ltd.), can be used to acquire spectra according to the following parameters. Method: proton complete decoupling method; Concentration: 220mg / mL; Solvent: Mixed solvent of 1,2,4-trichlorobenzene and deuterated benzene (volume ratio 90 / 10); Temperature: 130℃; Pulse width: 45°; Pulse repetition time: 4 seconds; Total number of times: 10,000; M = m / S x 100 R = γ / S x 100 S=Pββ+Pαβ+Pαγ <calculation formula> S=Pββ: 19.8~22.5 ppm Pαβ: 18.0~17.5 ppm Pαγ: 17.5~17.1 ppm γ: Racemic pentad chain: 20.7-20.3 ppm m: Meso-type pentad chain: 21.7~22.5 ppm.

[0115] In one embodiment, the elastomeric polyolefin includes a low isotactic polypropylene having an isotactic degree [mmmm] (mol%) of about 30, about 31, about 32, about 33, about 34, about 35, about 36, about 37, about 38, about 39, about 40, about 41, about 42, about 43, about 44, about 45, about 46, about 47, about 48, about 49, about 50, about 51, about 52, about 53, about 54, about 55, about 56, about 57, about 58, about 59, and about 60.

[0116] In one embodiment, the low isotactic polypropylene has an isotactic degree [mmmm] (mol%) of less than about 60, less than about 59, less than about 58, less than about 57, less than about 56, less than about 55, less than about 54, less than about 53, less than about 52, less than about 51, less than about 50, less than about 49, less than about 48, less than about 47, less than about 46, less than about 45, less than about 44, less than about 43, less than about 42, less than about 41, less than about 40, less than about 39, less than about 38, less than about 37, less than about 36, less than about 35, less than about 34, less than about 33, less than about 32, and less than about 31.

[0117] In some embodiments, the elastomeric polyolefin comprises low isotactic polypropylene having a crystallinity of about 30 to about 60 percent, e.g., 35 to 55 percent, e.g., 40 to 50 percent, preferably 42 to 48 percent. In one embodiment, the low isotactic polypropylene may have a crystallinity of about 44 to about 46 percent. The crystallinity of the low isotactic polypropylene may be measured according to ASTM D-3418-15.

[0118] In one embodiment, the elastomeric polyolefin includes low isotactic polypropylene having a typical MFR greater than 40 g / 10 min and a molecular weight less than 140,000 g / mol, and particularly having an MFR greater than 45 g / 10 min and a molecular weight less than 134,200 g / mol. In a preferred embodiment, the elastomeric polyolefin includes low isotactic polypropylene having a molecular weight of 124,200 g / mol to 134,200 g / mol and an MFR of about 45 to about 55 g / 10 min. Unless otherwise specified, the MFR is measured according to ASTM D-1238.

[0119] In one embodiment, the elastomeric polyolefin includes low isotactic polypropylene having a melting point greater than about 60°C, particularly about 60 to about 120°C, and more particularly about 60 to about 100°C. In one embodiment, the low isotactic polypropylene has a melting point of about 65 to about 85°C, particularly about 70 to about 80°C. The melting point of low isotactic polypropylene can be determined according to ISO 306 Method A50.

[0120] In one embodiment, the elastomeric polyolefin includes low-tacticity polypropylene having a molecular weight in the range of about 30,000 to about 150,000 g / mol, particularly about 44,200 to about 140,000 g / mol, and more particularly about 70,000 to about 134,200 g / mol. In a preferred embodiment, the low-isotactic polypropylene has a molecular weight of about 128,000 to about 132,000 g / mol.

[0121] In one embodiment, the elastomeric polyolefin is less than about 150,000 g / mol, less than about 144,200 g / mol, less than about 140,000 g / mol, less than about 138,000 g / mol, less than about 136,000 g / mol, less than about 134,000 g / mol, less than about 132,000 g / mol, less than about 130,000 g / mol, and about 1 Less than 28,000 g / mol, approximately less than 126,000 g / mol, approximately less than 124,000 g / mol, approximately less than 122,000 g / mol, approximately less than 120,000 g / mol, approximately less than 118,000 g / mol, approximately less than 116,000 g / mol, approximately less than 114,000 g / mol, approximately less than 112,000 g / mol, approximately less than 110,000 g / mol, approximately 108 Less than 1,000 g / mol, less than approximately 106,000 g / mol, less than approximately 104,000 g / mol, less than approximately 102,000 g / mol, less than approximately 100,000 g / mol, less than approximately 98,000 g / mol, less than approximately 96,000 g / mol, less than approximately 94,000 g / mol, less than approximately 92,000 g / mol, less than approximately 90,000 g / mol, less than approximately 88,000 g / mol It may have a molecular weight of less than 1, less than approximately 86,000 g / mol, less than approximately 84,000 g / mol, less than approximately 82,000 g / mol, less than approximately 80,000 g / mol, less than approximately 78,000 g / mol, less than approximately 76,000 g / mol, less than approximately 74,000 g / mol, less than approximately 72,000 g / mol, or less than approximately 70,000 g / mol.

[0122] In some embodiments, the low-isotactic polypropylene has a molecular weight lower than that of the first polypropylene polymer resin into which it is mixed. For example, in one embodiment of the present invention, the percentage difference in molecular weight between the first polypropylene polymer and the low-isotactic polypropylene is 5 to 150%. In one embodiment, the percentage difference is 7 to 120%. In a preferred embodiment, the percentage difference in molecular weight between the first polypropylene polymer and the low-isotactic polypropylene is about 20 to about 35%, more preferably about 25 to about 30%.

[0123] In the context of this invention, the percentage difference is calculated as follows:

[0124] Percentage difference

number

[0125] In one embodiment, the polypropylene polymer has a molecular weight of 172,000 g / mol, and the low isotactic polypropylene has a molecular weight of about 130,000, thereby providing a percentage difference of about 27.8%. In another embodiment, the first polypropylene may have a molecular weight of about 140,000 g / mol, and the low isotactic polypropylene may have a molecular weight of 130,000 g / mol, providing a percentage difference of about 7%. In a further embodiment, the first polypropylene may have a molecular weight of about 172,000 g / mol, and the low isotactic polypropylene may have a molecular weight of 44,200, providing a percentage difference of about 117%.

[0126] A suitable example of low-isotactic polypropylene is the trade name L-MODU 商標 It is available from Idemitsu Kosan Co., Ltd. under the following conditions. An example is S400 (approximately 2,600 MFRg / 10 min, 0.87 g / cm³). 3 The density of, and M w 45 kg / mol); S600 (390 MFRg / 10 min, 0.87 g / cm³) 3 The density of, and M w 75 kg / mol); and S901 (50 MFRg / 10 min, 0.87 g / cm³). 3 The density of, and M w It contains 130 kg / mol.

[0127] In other embodiments, the low-isotactic polypropylene may include a copolymer consisting of ethylene and propylene units.

[0128] Any ingredient

[0129] In some embodiments, the plurality of fibers may include one or more additional additives that are mixed with one or more polymers during the melt extrusion step. Examples of suitable additives include colorants (e.g., pigments, e.g., TiO2), UV stabilizers, hydrophobic agents, hydrophilic agents, antistatic agents, elastomers, compatibilizers, antioxidants, antiblocking agents, slip agents, surfactants, fluorescent whitening agents, flame retardants, antimicrobial agents, e.g., copper oxide and zinc oxide, etc.

[0130] In one embodiment, the plurality of fibers of the nonwoven fabric have a monocomponent configuration.

[0131] In one embodiment, the plurality of fibers of the nonwoven fabric have a multicomponent configuration, for example, a two-component configuration. For example, the plurality of fibers may have a sheath / core configuration, a side-by-side eccentric sheath / core configuration, an island-in-the-sea configuration, and the like.

[0132] In one embodiment, the plurality of fibers include a two-component fiber having a first polymer component and a second polymer component, each component constituting a separate region of the fiber. In such an embodiment, the elastomeric polyolefin may be present in either the first polymer component or the second polymer component, or in both the first polymer component and the second polymer component.

[0133] In one embodiment, the configuration of the multi-component fiber is a side-by-side arrangement, where a first polymer component defines a first continuous distinct zone extending along the length of the fiber, and a second polymer component defines a second continuous distinct zone extending along the length of the fiber. Both the first and second polymer components define at least a portion of the outer surface of the continuous fiber. In one embodiment, the first distinct region and the second distinct region of the side-by-side continuous fiber exist in a ratio ranging from 10:90 to 90:10, particularly about 40:60 to 60:40, and more particularly about 50:50. The side-by-side configuration is particularly useful in the preparation of crimped fibers. Other configurations that may be useful in the preparation of crimped fibers include eccentric sheath / core configurations and D-centric sheath / core configurations.

[0134] A preferred configuration is a sheath / core arrangement in which the first component, the sheath, substantially surrounds the second component, the core. The resulting sheath / core two-component fiber may have a circular or non-circular cross-section. Other structured fiber configurations known to those skilled in the art, including segmented pie, island-in-the-sea, and tipped multilobal structures, can be used.

[0135] In one embodiment, the plurality of fibers are two-component, where a first polymer component defines the fiber sheath and a second polymer component defines the fiber core. Generally, the weight percentage of the sheath to the weight percentage of the core in the plurality of fibers can vary considerably depending on the desired properties of the nonwoven fabric. For example, the ratio of the sheath to the core can vary in the range of about 5:95 to about 95:5, for example, about 10:90 to about 90:10, and particularly about 20:80 to about 80:20. In a preferred embodiment, the weight ratio of the sheath to the core is about 25:75 to about 35:65, with a weight ratio of about 30:70 to 50:50 being particularly preferred.

[0136] In one embodiment, the plurality of fibers have a two-component structure in which both the core and the sheath comprise a first polypropylene polymer of the same type, and either the sheath or the core comprises the elastomeric polyolefin, which is present in an amount of about 1 to about 99 weight percent of the total weight of the components in which the elastomeric polyolefin is present, more particularly in an amount of about 5 to about 30 weight percent, more particularly in an amount of about 10 to about 25 weight percent, and even more particularly in an amount of about 15 to about 20 weight percent, based on the total weight of the sheath components.

[0137] In one embodiment, the elastomeric polyolefin may be present only in the core of the two-component fiber and not in the sheath, or present only in the sheath and not in the core, or the highly elastomeric polyolefin may be present in both the sheath and the core. In another embodiment, the elastomeric polyolefin may be present in the polymer blend in both the first component and the second component, but not in the same concentration. For example, the amount of elastomeric polyolefin in the polymer blend of the sheath may be greater or less than the amount of elastomeric polyolefin in the polymer blend of the core.

[0138] In one embodiment, the core comprises a polymer blend containing the first polypropylene polymer resin and the elastomeric polyolefin, while the sheath comprises a polymer or polymer blend different from the polymer or polymer blend of the core. In such an embodiment, the sheath may comprise a wide variety of polymers that can be used to prepare a nonwoven fabric according to embodiments of the present disclosure.

[0139] In such embodiments, the first polymer component, for example, the sheath, may comprise a wide variety of polymers and polymer blends.

[0140] Suitable polymers for preparing such multi-component fibers include polyolefins, such as polypropylene and polyethylene, and their copolymers; polyesters, such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polybutylene terephthalate (PBT); nylon; polystyrene; polyurethane; copolymers and blends thereof; and other synthetic polymers that may be used in the preparation of fibers. In some embodiments, the polymer is polyolefin, polyester, polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polytrimethylene terephthalate, polymethyl methacrylate, polyamide, nylon, polyacrylic, polystyrene, polyvinyl, polytetrafluoroethylene, ultrahigh molecular weight polyethylene, very high molecular weight polyethylene, high molecular weight polyethylene, polyether ether ketone, non-fibrous plasticized cellulose, polyethylene, polypropylene, polybutylene, polymethylpentene, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polystyrene, acrylonitrile-butadiene-styrene, styrene-acrylonitrile, styrene triblock copolymer and styrene tetrablock copolymer, styrene-butadiene, styrene-maleic anhydride, ethylene vinyl acetate, ethylene vinyl alcohol, polyvinyl chloride, cellulose acetate, cellulose acetate butyrate, plasticized cellulose. Cellulosics, cellulose propionate, ethylcellulose, natural fibers, any derivative thereof, any polymer blend thereof, any copolymer thereof, or any combination thereof can be selected from the group.

[0141] In further embodiments, nonwoven fabrics according to one or more embodiments of the present invention may be prepared to include multi-component fibers, the multi-component fibers comprising a first polymer component comprising a polymer blend of the first polypropylene polymer resin and the elastomeric polypropylene, and a second polymer component comprising a bio-based material, particularly a bio-based polymer. In contrast to petroleum-derived polymers, bio-based polymers are generally obtained from bio-based materials. In some embodiments, bio-based polymers may also be considered biodegradable. A special classification of biodegradable products made from bio-based materials may be considered compostable if they can be decomposed in a composting environment. European standard EN 13432, "Proof of Compostability of Plastic Products," can be used to determine whether a textile or film made of sustainable components can be classified as compostable.

[0142] In one embodiment, the nonwoven fabric may include fibers comprising the bio-based polymer and polymer blend described above. In some embodiments, the fibers may have a two-component structure (in which the first polymer component comprises a polymer blend comprising the first polypropylene and the elastomeric polyolefin, and the second polymer component comprises the bio-based polymer), for example, a sheath / core structure (in which the polymer blend comprising the first polypropylene and the elastomeric polyolefin constitutes the sheath of the fiber, and the bio-based polymer constitutes the core of the fiber).

[0143] In one embodiment, the bio-based polymers used may include aliphatic polyester polymers, such as polylactic acid, and bio-based polyethylene.

[0144] Aliphatic polyesters useful in the present invention may include homopolymers and copolymers of poly(hydroxyalkanoates), as well as homopolymers and copolymers of aliphatic polyesters obtained from reaction products of one or more polyols and one or more polycarboxylic acids (typically formed from reaction products of one or more alkanediols and one or more alkanedicarboxylic acids (or acyl derivatives)). Polyesters may further be derived from polyfunctional polyols, such as glycerin, sorbitol, pentaerythritol, and combinations thereof, to form branched, star-shaped, and graft-shaped homopolymers and copolymers. Polyhydroxyalkanoates are generally formed from hydroxy acid monomer units or derivatives thereof. These include, for example, polylactic acid, polyhydroxybutyrate, polyhydroxyvalerate, polycaprolactone, etc. Miscible and immiscible blends of aliphatic polyesters with one or more additional semicrystalline or amorphous polymers may also be used.

[0145] One useful class of aliphatic polyesters includes poly(hydroxyalkanoates) obtained by condensation polymerization or ring-opening polymerization of hydroxy acids or their derivatives. A suitable poly(hydroxyalkanoate) may be represented by the following formula: H(O--R--C(O)--) nOH, where R is a linear or branched alkylene moiety having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, which may optionally be substituted with catenary oxygen atoms (bonded to carbon atoms in the carbon chain); n is a number such that the ester is a polymer, preferably such that the molecular weight of the aliphatic polyester is at least 10,000 daltons, preferably at least 30,000 daltons, and most preferably at least 50,000 daltons. In some embodiments, the molecular weight of the aliphatic polyester is typically less than 1,000,000 daltons, preferably less than 500,000 daltons, and most preferably less than 300,000 daltons. R may further contain one or more catenary (i.e., intrachain) ether oxygen atoms. Generally, the R group of a hydroxy acid is configured such that the pendant hydroxyl group is a primary or secondary hydroxyl group.

[0146] Useful poly(hydroxyalkanoates) include, for example, poly(3-hydroxybutyrate), poly(4-hydroxybutyrate), poly(3-hydroxyvalerate), poly(lactic acid) (also known as polylactide), poly(3-hydroxypropanoate), poly(4-hydroxypentanoate), poly(3-hydroxypentanoate), poly(3-hydroxyhexanoate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), polydioxanone, polycaprolactone, and homopolymers and copolymers of polyglycolic acid (i.e., polyglycolic acid). Two or more copolymers of the above hydroxy acids, for example, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(lactate-co-3-hydroxypropanoate), poly(glycolide-co-p-dioxanone), and poly(lactic acid-co-glycolic acid) may also be used. Blends of two or more poly(hydroxyalkanoates), and blends of one or more semicrystalline or amorphous polymers and / or copolymers may also be used.

[0147] The aliphatic polyester may be a block copolymer of poly(lactic acid-coglycolic acid). Aliphatic polyesters useful in the compositions of the present invention include homopolymers, random copolymers, block copolymers, star-branched random copolymers, star-branched block copolymers, dendritic copolymers, hyperbranched copolymers, graft copolymers, and combinations thereof.

[0148] Another useful class of aliphatic polyesters includes those obtained from the reaction products of one or more alkanediols and one or more alkanedicarboxylic acids (or acyl derivatives). Such polyesters have the following general formula: [ka] Here, R' and R'' each represent an alkylene moiety which may be linear or branched having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, and m is a number such that the ester is a polymer, preferably such that the molecular weight of the aliphatic polyester is at least 10,000 daltons, preferably at least 30,000 daltons, most preferably at least 50,000 daltons, but less than 1,000,000 daltons, preferably less than 500,000 daltons, most preferably less than 300,000 daltons. Each n is independently 0 or 1. R' and R'' may further contain one or more catenary (i.e., intrachain) ether oxygen atoms.

[0149] Examples of aliphatic polyesters include homopolymers and copolymers obtained from the following: (a) one or more of the following diacides (or derivatives thereof): succinic acid; adipic acid; 1,12-dicarboxydodecane; fumaric acid; glutaric acid; diglycolic acid; and maleic acid; and (b) one or more of the following diols: ethylene glycol; polyethylene glycol; 1,2-propanediol; 1,3-propanediol; 1,2-propanediol; 1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2,3-butanediol; 1,6-hexanediol; 1,2-alkanediols having 5 to 12 carbon atoms; diethylene glycol; Polyethylene glycol having a molecular weight of 300 to 10,000 daltons, preferably 400 to 8,000 daltons; propylene glycol having a molecular weight of 300 to 4,000 daltons; block copolymers or random copolymers derived from ethylene oxide, propylene oxide or butylene oxide; dipropylene glycol; and polypropylene glycol, as well as (c) optionally small amounts, i.e., 0.5 to 7.0 mole percent, of polyols having more than two functional groups, such as glycerol, neopentyl glycol and pentaerythritol.

[0150] Such polymers may include polybutylene succinate homopolymers, polybutylene adipate homopolymers, polybutylene adipate-succinate copolymers, polyethylene succinate-adipate copolymers, polyethylene glycol succinate homopolymers, and polyethylene adipate homopolymers.

[0151] Commercially available aliphatic polyesters include poly(lactide), poly(glycolide), poly(lactide-co-glycolide), poly(L-lactide-co-trimethylene carbonate), poly(dioxanone), poly(butylene succinate), and poly(butylene adipate).

[0152] The term "aliphatic polyester" includes not only polyesters made solely from aliphatic and / or alicyclic components, but also polyesters containing aromatic units in addition to aliphatic and / or alicyclic units, as long as the polyester has a substantial bio-based content.

[0153] In addition to the PLA-based resin, the nonwoven fabric according to embodiments of the present invention may also contain other polymers derived from aliphatic components having one carboxylic acid group and one hydroxyl group, which are also called polyhydroxyalkanoates (PHAs). Examples include polyhydroxybutyrate (PHB), poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), poly(hydroxybutyrate-co-polyhydroxyhexanoate) (PHBH), polyglycolic acid (PGA), poly(epsilon-caprolactone) (PCL), preferably polylactic acid (PLA).

[0154] Examples of additional polymers that may be used in embodiments of the present invention include polymers obtained from a combination of an aliphatic component having two carboxylic acid groups and an aliphatic component having two hydroxyl groups, and polyesters obtained from aliphatic diols and aliphatic dicarboxylic acids, such as polybutylene succinate (PBS), polyethylene succinate (PES), polybutylene adipate (PBA), polyethylene adipate (PEA), and polytetramethylene adipate / terephthalate (PTMAT).

[0155] Useful aliphatic polyesters include those derived from semi-crystalline polylactic acid. Poly(lactic acid) or polylactide (PLA) has lactic acid as its main degradation product, which is widely found in nature, non-toxic, and widely used in the food, pharmaceutical, and medical industries. The polymer can be prepared by ring-opening polymerization of lactide, which is a lactic acid dimer. Lactic acid is optically active, and its dimers are found in four different forms: L,L-lactide, D,D-lactide, D,L-lactide (meso-lactide), and a racemic mixture of L,L-lactide and D,D-lactide. By polymerizing these lactides as pure compounds or blends, poly(lactide) polymers with different stereochemical structures and physical properties (including crystallineity) can be obtained. L,L- or D,D-lactide produces semi-crystalline poly(lactide), while poly(lactide) derived from D,L-lactide is amorphous.

[0156] Generally, polylactic acid-based polymers are prepared from dextrose, a sugar source derived from corn. In North America, corn is used because it is the most economical source of plant starch, which is ultimately converted into sugar. However, it should be recognized that dextrose can also be obtained from raw materials other than corn. The sugar is converted to lactic acid or lactic acid derivatives through fermentation using microorganisms. The lactic acid is then polymerized to form PLA. In addition to corn, other agricultural sugar sources may be used, including rice, sugar beets, sugarcane, wheat, cellulosic materials, and xylose recovered from wood pulp processing, for example.

[0157] Polylactides preferably have a high enantiomer ratio to maximize the intrinsic crystallinity of the polymer. The crystallinity of poly(lactic acid) is based on the regularity of the polymer backbone and its ability to crystallize with other polymer chains. When a relatively small amount of one enantiomer (e.g., D-) copolymerizes with the other enantiomer (e.g., L-), the polymer chain becomes irregular in shape, and crystallinity decreases. For these reasons, when crystallinity is important, it is desirable that poly(lactic acid) be at least 85% single isomer, at least 90% single isomer, or at least 95% single isomer to maximize crystallinity.

[0158] In some embodiments, nearly equimolar blends of D-polylactide and L-polylactide are also useful. In some embodiments, this blend forms a unique crystalline structure with a higher melting point than D-poly(lactide) and L-(polylactide) alone, and has improved thermal stability.

[0159] Copolymers of poly(lactic acid) and other aliphatic polyesters (including block copolymers and random copolymers) may also be used. Useful comonomers include glycolides, beta-propiolactone, tetramethylglycolide, beta-butyrolactone, gamma-butyrolactone, pivalolactone, 2-hydroxybutyric acid, alpha-hydroxyisobutyric acid, alpha-hydroxyvaleric acid, alpha-hydroxyisovaleric acid, alpha-hydroxycaproic acid, alpha-hydroxyethylbutyric acid, alpha-hydroxyisocaproic acid, alpha-hydroxy-beta-methylvaleric acid, alpha-hydroxyoctanoic acid, alpha-hydroxydecanoic acid, alpha-hydroxymyristic acid, and alpha-hydroxystearic acid.

[0160] Blends of poly(lactic acid) with one or more other aliphatic polyesters or one or more other polymers may also be used. Examples of useful blends include poly(lactic acid) and poly(vinyl alcohol), polyethylene glycol / polysuccinate, polyethylene oxide, polycaprolactone, and polyglycolide.

[0161] In one preferred embodiment, the aliphatic polyester comprises a PLA-based resin. A wide variety of different PLA resins can be used to produce nonwoven fabrics according to embodiments of the present invention. The PLA resin should have suitable molecular properties for spinning in a spunbond process. Examples of suitable PLA resins are supplied by NatureWorks LLC at Minnetonka, Minn. 55345, for example, grades 6752D, 6100D, and 6202D, which are considered to be produced in general accordance with the teachings of U.S. Patent Nos. 5,525,706 and 6,807,973 to Gruber et al. Other examples of suitable PLA resins include L130, L175, and LX175, all of which are from Corbion at Arkelsedijk 46, 4206 AC Gorinchem, the Netherlands.

[0162] In some embodiments, the nonwoven fabric of the present invention may contain a bio-based polymer component of a biodegradable product, the bio-based polymer component being derived from an aliphatic component having one carboxylic acid group (or a polyester-forming derivative thereof, e.g., an ester group) and one hydroxyl group (or a polyester-forming derivative thereof, e.g., an ether group), or from a combination of an aliphatic component having two carboxylic acid groups (or a polyester-forming derivative thereof, e.g., an ester group) and an aliphatic component having two hydroxyl groups (or a polyester-forming derivative thereof, e.g., an ether group) and an aliphatic component having two hydroxyl groups (or a polyester-forming derivative thereof, e.g., an ether group).

[0163] Additional non-limiting examples of bio-based polymers include polymers produced directly from organisms, such as polyhydroxyalkanoates (e.g., poly(beta-hydroxyalkanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), NODAX 商標 ), and bacterial cellulose; polymers extracted from plants and biomass, such as polysaccharides and their derivatives (e.g., gum, cellulose, cellulose esters, chitin, chitosan, starch, chemically modified starch), proteins (e.g., zein, whey, gluten, collagen), lipids, lignin, and natural rubber; and current polymers obtained from naturally derived monomers and derivatives, such as biopolyethylene, biopolypropylene, polytrimethylene terephthalate, polylactic acid, nylon 11, alkyd resins, succinate polyester, and biopolyethylene terephthalate.

[0164] In some embodiments, the bio-based polymer may include bio-based polyethylene, bio-based polypropylene, and bio-based polyester, such as bio-based PET, derived from biological raw materials. For example, bio-based polyethylene can be prepared from sugars fermented to produce ethanol, which is further dehydrated to provide ethylene. A suitable example of sugarcane-derived polyethylene is available from Braskem SA under trade name PE SHA7260.

[0165] Nonwoven properties

[0166] According to one embodiment, for example, the nonwoven fabric may have a basis weight ranging from about 5 grams per square meter (gsm) to about 150 gsm, depending on the number of layers in the nonwoven fabric and the composition of each layer.

[0167] In particular, the nonwoven fabric may have a standard weight of about 8 gsm to about 150 gsm. In one embodiment, for example, the nonwoven fabric may have a standard weight of about 10 gsm to about 70 gsm. In another embodiment, for example, the nonwoven fabric may have a standard weight of about 11 gsm to about 40 gsm. In one embodiment, the nonwoven fabric may have a standard weight of about 15 gsm to about 25 gsm. Therefore, in one embodiment, the nonwoven fabric may have any of the following thicknesses: at least 5 gsm, at least 6 gsm, at least 7 gsm, at least 8 gsm, at least 9 gsm, at least 10 gsm, at least 11 gsm, at least 12 gsm, at least 13 gsm, at least 14 gsm, and at least 15 gsm, and / or up to about 150 gsm, up to about 100 gsm, up to about 70 gsm, up to about 60 gsm, up to about 50 gsm, up to about 40 gsm, and up to about 30 gsm (for example, about 9 to 60 gsm, about 11 to 40 gsm, about 20 to 35 gsm, etc.).

[0168] Advantageously, nonwoven fabrics according to embodiments of the present disclosure may have fibers typically having a linear mass density of about 0.7 dtex to about 1.7 dtex. In some embodiments, the plurality of fibers may have a linear mass density of at least about 0.81 dtex, at least about 0.85 dtex, at least about 0.90 dtex, at least about 0.95 dtex, at least about 1.0 dtex, at least about 1.05 dtex, at least about 1.10 dtex, at least about 1.15 dtex, at least about 1.20 dtex, at least about 1.25 dtex, at least about 1.30 dtex, at least about 1.35 dtex, at least about 1.40 dtex, at least about 1.45 dtex, at least about 1.50 dtex, at least about 1.55 dtex, at least about 1.60, and at least about 1.65 dtex. It may have any of the following values: a maximum of approximately 1.65 dtex, a maximum of approximately 1.60 dtex, a maximum of approximately 1.55 dtex, a maximum of approximately 1.50 dtex, a maximum of approximately 1.45 dtex, a maximum of approximately 1.40 dtex, a maximum of approximately 1.35 dtex, a maximum of approximately 1.30 dtex, a maximum of approximately 1.25 dtex, a maximum of approximately 1.20 dtex, a maximum of approximately 1.15 dtex, a maximum of approximately 1.10 dtex, a maximum of approximately 1.05 dtex, a maximum of approximately 1.00 dtex, a maximum of approximately 0.95 dtex, a maximum of approximately 0.90 dtex, a maximum of approximately 0.85 dtex, and a maximum of approximately 0.80 dtex (for example, approximately 0.70 to approximately 1.65 dtex, approximately 0.75 to approximately 1.60 dtex, approximately 0.8 to 1.4 dtex, etc.).

[0169] In one embodiment, a nonwoven fabric according to an embodiment of the present invention exhibits improvement in one or more of the following compared to a similarly prepared nonwoven fabric (except that the similar nonwoven fabric does not contain elastomeric polyolefins in the polymer blend and the filaments are finely shredded and stretched under a cabin operating pressure of less than 4,200 Pa): elongation, abrasion resistance, fiber fineness, and flexibility.

[0170] In one embodiment, a similarly prepared nonwoven fabric is substantially identical to the nonwoven fabric of the present invention (e.g., polymer chemical composition except for the elastomeric polyolefin and cabin operating pressure). Some modifications to the process conditions used in the similarly prepared nonwoven fabric may exist, such as slight variations in calender temperature and pressure.

[0171] In one embodiment of the present disclosure, a nonwoven fabric in accordance with the views of the present disclosure is characterized by a reduction of at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, and at least 35% in fiber fineness (dtex) compared to a nonwoven fabric prepared under identical conditions, except that it does not contain an elastomeric polyolefin blended with the polypropylene resin and is stretched and finened at a cabin pressure of less than 4,200 Pa.

[0172] In a preferred embodiment, a nonwoven fabric according to the views of this disclosure is characterized by having an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex.

[0173] In one embodiment, the nonwoven fabric exhibits a percentage reduction in fiber dtex of approximately 5 to approximately 60%, for example, a percentage reduction in fiber dtex of 15 to 50%, a percentage reduction in fiber dtex of 10 to 30%, or a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0174] In addition, nonwoven fabrics according to embodiments of the present invention demonstrate improved flexibility, as demonstrated by both MD bending and CD bending.

[0175] In one embodiment, the nonwoven fabric exhibits mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm.

[0176] In one embodiment, the nonwoven fabric exhibits one or more machine-direction flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more transverse flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm.

[0177] In one embodiment, the nonwoven fabric exhibits machine direction flexibility of at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm, and exhibits transverse direction flexibility of at least 16 mm, at least 18 mm, at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm.

[0178] In one embodiment, the nonwoven fabric has an average machine direction / transverse bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm. For example, the nonwoven fabric may have an average machine direction / transverse bending flexibility of at least one of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, and an average machine direction / transverse bending flexibility of at least one of at least 40 mm, 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm.

[0179] In some embodiments, the nonwoven fabric exhibits a percentage reduction in mechanical bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomeric polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0180] In one embodiment, the nonwoven fabric exhibits an average percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0181] In some embodiments, the nonwoven fabric exhibits an average percentage reduction in mechanical / transverse bending flexibility of at least one of the following percentages: at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0182] In some embodiments, the nonwoven fabric exhibits an average percentage reduction in mechanical / transverse bending flexibility of one or more of the following, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa: less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%.

[0183] Advantageously, improvements in flexibility and fiber fineness are accompanied by little or no decrease in mechanical properties compared to nonwovens prepared under identical conditions, except that the nonwovens do not contain elastomer polyolefins and are stretched and finened at a cabin pressure of less than 4,200 Pa. In some embodiments, the nonwovens of the present invention showed improvements in both tensile strength and elongation.

[0184] For example, the nonwoven fabric may show an increase in MD tensile strength and CD tensile strength ranging from about 2% to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0185] In one embodiment, the nonwoven fabric may exhibit an increase in elongation percentage in one or more of the machine direction or transverse direction, ranging from about 5% to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomeric polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0186] In one embodiment, a nonwoven fabric according to an embodiment of the present invention may be characterized by having one or more of the following features: a) Average fiber fineness in the range of approximately 0.8 to 1.6 dtex, particularly approximately 0.9 to 1.4 dtex, and more particularly approximately 1.2 to 1.35 dtex; b) The nonwoven fabric exhibits a percentage reduction in fiber dtex of approximately 5 to 60%, for example, a percentage reduction in fiber dtex of 15 to 50%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa; c) The nonwoven fabric exhibits mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm; d) The nonwoven fabric exhibits one or more machine-direction flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more transverse flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, less than 20 mm, less than 18 mm, and less than 16 mm; e) exhibiting at least one mechanical directional flexibility of at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm and at least 48 mm, and at least one lateral flexibility of at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm; f) Average mechanical direction / lateral bending flexibility in the range of 25-40 mm, particularly about 28-38 mm, for example, one or more of the average mechanical direction / lateral bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / lateral bending flexibility is one or more of the average mechanical direction / lateral bending flexibility of less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and 20 mm; g) A percentage reduction in mechanical directional bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa; h) An average percentage reduction in mechanical / transverse bending flexibility of the nonwoven fabric compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa, which is about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%; i) The nonwoven fabric exhibits an average percentage reduction in mechanical / transverse bending flexibility of at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40% compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa; j) The nonwoven fabric exhibits an average percentage reduction in mechanical / transverse bending flexibility of less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa; k) An increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa; and, l) An increase in elongation percentage in one or more directions, ranging from about 5% to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0187] In one embodiment, a nonwoven fabric according to an embodiment of the present invention has two or more of the following features: a) Average fiber fineness in the range of approximately 0.8 to 1.6 dtex, particularly approximately 0.9 to 1.4 dtex, and more particularly approximately 1.2 to 1.35 dtex; b) A percentage reduction in fiber dtex of approximately 5 to approximately 60%, for example, 10 to 50% or 15 to 25%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely processed at a cabin pressure of less than 4,200 Pa; c) Mechanical direction bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm; d) One or more mechanical directional flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more lateral flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, less than 20 mm, less than 18 mm, and less than 16 mm; e) at least one mechanical directional flexibility of at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm and at least 48 mm, and at least one lateral flexibility of at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm; f) Average mechanical direction / lateral bending flexibility in the range of 25-40 mm, particularly about 28-38 mm, for example, one or more of the average mechanical direction / lateral bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / lateral bending flexibility is one or more of the following: less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm; g) A percentage reduction in mechanical directional bending flexibility of about 20-40%, particularly about 25-35%, and more particularly about 26-32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa; h) An average percentage reduction in mechanical / transverse bending flexibility of about 20-40%, particularly about 20-35%, and more particularly about 22-30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa; i) An average percentage reduction in mechanical / transverse bending flexibility of at least one of the following: at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa; j) An average percentage reduction in mechanical / transverse bending flexibility of less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa; k) An increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa; and, l) An increase in elongation percentage in one or more of the mechanical or transverse directions, ranging from about 5% to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0188] In one embodiment, a nonwoven fabric according to an embodiment of the present invention may be characterized by having at least the following features: a) Approximately 0.8 to 1.6 dtex, especially approximately 0.9 to 1.4 dtex, and more specifically approximately 1.2 to 1.35 dtex. Average fiber fineness within the range; b) A percentage reduction in fiber dtex of about 5 to about 30%, for example, a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely processed at a cabin pressure of less than 4,200 Pa; and, c) Mechanical bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm.

[0189] Softness bending is measured according to WSP90.1.

[0190] In one embodiment, the nonwoven fabric according to the embodiment of the present invention has an adhesive area percentage of about 9.6 to about 14%, and an adhesive area of ​​about 0.10 to about 0.25 mm. 2 The average of the individual bonding areas is approximately 4 to 7.25 mm. -1 It can be characterized by having an average bonding point filling value and a surface having an adhesive pattern having one or more of the features of a) to l) above.

[0191] System and method for preparing the nonwoven fabric

[0192] A certain aspect of the present invention provides a system and method for preparing a nonwoven fabric according to the embodiments described above.

[0193] Referring to Figure 2, for example, a schematic diagram of a spunbond nonwoven fabric preparation system according to one embodiment of the present invention is shown, schematically indicated by reference numeral 100a. As shown in Figure 2, a first polymer source (i.e., hopper) 102 is in fluid communication with a spunbond spinning beam 104 via an extruder 106. It should be understood that other nonwoven fabric formation systems, such as meltblown, carded, air-bonded, resin-bonded, spunlace, etc., may be used according to one embodiment of the present invention.

[0194] In one embodiment, an elastomeric polyolefin polymer source (not shown) is in fluid communication with either a hopper 102 or an extruder 106. The elastomeric polyolefin may be blended with a polypropylene polymer in the hopper, or it may be separately metered and supplied into the extruder.

[0195] In one embodiment, the first polymer source may supply a polymer stream of molten or semi-molten polymer resin. After extrusion, the extruded polymer stream, containing a mixture of the polymer and an elastomeric polyolefin, is introduced into a spunbond spinning beam 104, at which point a plurality of molten or semi-molten polymer streams are introduced into a die block (not shown) of the spunbond spinning beam. The die block includes a plurality of rows of fluid orifices extending laterally across the spunbond spinning beam. As the extruded filament is discharged from the fluid orifices, cooling air is directed laterally across the extruded filament and then flows downward with the filament through a partially enclosed cabin system (not shown) to cool, draw, and attenuate the filament. Conventionally, the discharge rate and air pressure (also referred to as cabin pressure) of the polymer flow within the cabin system are maintained at a cabin pressure of less than 4,000 Pa to avoid undesirable deformation and / or breakage of the fibers that may occur as the filament is stretched through the cabin system.

[0196] In one embodiment of this disclosure, the inventors have found that by incorporating an elastomeric polyolefin into the polymer blend, it is possible to use higher cabin pressures without causing fiber breakage or deformation. As a result, the higher cabin pressures result in the formation of fine fibers with a denier reduction beyond the range that would normally occur in the absence of an elastomeric polymer.

[0197] In conventional spunbond processes for forming polypropylene fibers, the system and method are typically operated at cabin pressures of less than 4,000 Pa. In embodiments of this disclosure, the presence of the elastomeric polyolefin allows for higher cabin pressures without experiencing fiber breakage and / or fiber deformation. Fiber breakage is particularly undesirable because it results in unsightly and / or defective material, potentially requiring the spunbond process to be stopped, cleaned, and restarted.

[0198] In one embodiment, the polypropylene fibers are spun at a cabin pressure exceeding 4,200 Pa, particularly in the range of about 4,200 Pa to 9,500 Pa.

[0199] While we do not wish to be bound by theory, it is believed that the presence of elastomeric polyolefins in the polymer blend reduces the maximum strain rate and stretching stress experienced by the fibers, thereby allowing them to be subjected to higher cabin pressures without fiber breakage or deformation. As the fibers are stretched and thinned within the cabin system, the higher cabin pressure results in further extension and elongation of the fibers. As a result, low-denier fine fibers can be obtained that would not be possible with the same process without elastomeric polyolefins in the polymer blend.

[0200] After leaving the cabin system, the spunbond fibers 107 are deposited on the collection surface 110 to form a web of filaments. At this stage, the filaments may form a web of filaments 112 that is either unglued or slightly unglued to each other.

[0201] In one embodiment, an optional bonding unit 116 is positioned downstream of the collection surface 110 and configured and positioned to thermally bond fibers together to form a single web. During the thermal bonding of the fiber web 112, the fibers are heated to a temperature sufficient to soften at least one polymer component constituting the fibers of the web 112, thereby producing a bonded nonwoven fabric 124. In one embodiment, the bonded nonwoven fabric 124 is moved to a winder 118, where it is then wound onto a roll.

[0202] In one embodiment, the bonding unit comprises an air-through bonder, in which the fibers are exposed to one or more heated gas streams, such as air. In another embodiment, the bonding unit may comprise a calendar bonding unit comprising a pair of cooperating heated rolls, at least one of which has a plurality of raised bonding points on its surface. These bonding points can be used to impart a bonding pattern to at least one surface of the nonwoven fabric. In some embodiments, the calendar comprises a pair of cooperating rolls, in which the first roll comprises an engraved patterned roll having a plurality of bonding points extending from its surface, and the second roll comprises a smooth surface or an anvil surface. During bonding, the spunbond fiber web passes between a pair of cooperative rolls, which are heated to a temperature sufficient to soften at least one polymer component containing the filaments that make up the web, so that the softened polymer component fuses and adheres with adjacent filaments in the web to form a bonded nonwoven fabric.

[0203] The bonding points of the engraved roll may have various shapes, such as rod-shaped, elliptical, square, rhombic, hexagonal, circular, etc., extending transversely, in the machine direction, or both. The surface area and density of the bonding points may be selected so that 5 to 30% of the surface area of ​​the nonwoven fabric is heat-bonded at individually spaced heat-bonding points. In one embodiment, about 5 to about 20 percent, and particularly about 8 to about 14 percent, of the surface area of ​​the nonwoven fabric is heat-bonded.

[0204] In one embodiment, it was also discovered that improvements in the abrasion resistance and flexibility of a nonwoven fabric can be obtained by using a calendering unit. In this calendering unit, an engraved patterned roll is provided with bonding points for providing a first bond pattern on the surface of the nonwoven fabric, comprising a plurality of alternating arrays of individual bonding points extending in the machine direction, transverse direction, and diagonal direction of the nonwoven fabric. In the first bond pattern, the total bonded surface area of ​​the nonwoven fabric is less than 14%, and the surface area of ​​the individual bonding points is approximately 0.10 to approximately 0.60 square millimeters (mm²). 2 ) and the bond point packing value is approximately 3.5 mm -1 It is extremely high, and the adhesive density is per square centimeter (cm²). 2 There are approximately 20 to 60 individual bonding points per surface area. More specifically, it has been observed that adhesive patterns satisfying these characteristics help to provide nonwoven fabrics with improved flexibility and abrasion resistance compared to similar nonwoven fabrics having a larger percentage of bonded surface area. Nonwoven fabrics having such adhesive patterns, systems and methods associated therewith are described in detail in concurrently pending U.S. Provisional Patent Application No. 63 / 454,941, filed on 27 March 2023 (published as U.S. Patent Publication No. ___ / _______), the contents of which are incorporated herein by reference in their entirety for all purposes.

[0205] In some embodiments, the fiber web is stabilized by compression using an optional pair of cooperating rolls 120 (referred to herein as “press rolls”) before being fed to a winder 118 or an optional bonding unit 116 for bonding. The use of press rolls may be desirable in the spunbond manufacturing process. In some embodiments, for example, if the press rolls are present, they may have a ceramic coating deposited on their surface. In some embodiments, for example, the first roll of the pair of cooperating rolls 120 may be positioned above the collection surface 110, and the second roll of the pair of cooperating rolls 120 may be positioned below the collection surface 110. In some embodiments, the system may also include a hot air knife (not shown) for exposing the fiber web 112 to a flow of heated gas, such as air, to lightly bond and stabilize the fiber web.

[0206] In some embodiments, the system 100a may further include a vacuum source 128 located below the collection surface 110. The vacuum source 128 provides a vacuum that helps draw and pull the fibers 107 on the collection surface 110.

[0207] Referring to Figure 3, further aspects of a system and method for preparing a nonwoven fabric according to at least one embodiment of the present invention are shown, broadly designated by reference numeral 100b. In this embodiment, system 100b may be configured and arranged to produce multi-component spunbond fibers, for example, two-component spunbond fibers.

[0208] System 100b includes a first polymer source (i.e., hopper) 130a that is in fluid communication with a spunbond spin beam 134 via an extruder 136a. A second polymer source (i.e., hopper) 130b is also in fluid communication with a spunblown spin beam 134 via an extruder 136b. In the preparation of a multi-component nonwoven fabric, the first polymer source may provide a flow of a first polymer resin, and the second polymer source may provide a flow of a second polymer resin. In melt spinning applications, the polymer flow is typically in a molten state or a semi-molten state. The first and second polymer resins may be different polymers or the same polymer, depending on the application of the nonwoven fabric and the desired properties. For example, the first polymer resin may include a first polymer blend comprising a first polypropylene polymer and an elastomeric polyolefin, and the second polymer resin may include a second polypropylene resin, for example, a second polypropylene resin, or a chemically different type of polymer. In some embodiments, the first polymer resin and the second polymer resin may be the same as or different from each other.

[0209] After extrusion, the extruded polymer stream is introduced into a spunbond spinning beam 134, at which point multiple polymer streams are introduced into a die head (not shown) of the spunbond spinning beam. The die head comprises multiple fluid orifices and associated cabin systems (not shown) for stretching and thinning the polymer stream discharged from the die head to generate a stream of spunbond fibers.

[0210] The spinning beam 134 generates multiple multi-component spunbond fibers 138, which are deposited on the collection surface 110 to form a spunbond fiber web 140. At this stage, the spunbond web may consist of a web 140 of multi-component fibers that are not bonded to each other or are only slightly bonded.

[0211] As described above, the fibers discharged from the spinning beam are introduced into the cabin system, where they are stretched and finened. Within the cabin system, the fibers are subjected to a cabin pressure exceeding 4,200 Pa to produce fibers with improved fineness and flexibility.

[0212] In one embodiment, an optional bonding unit 116 is positioned downstream of the collection surface 110 and configured and positioned to thermally bond filaments together to form a coherent web. During the thermal bonding of the fiber web 140, at least one polymer component constituting the web fibers 140 is heated to a temperature sufficient to soften, thereby producing a bonded nonwoven fabric 142. In one embodiment, the bonded or unbonded nonwoven fabric is moved to a winder 118, where it is then wound onto a roll.

[0213] In one embodiment, the bonding unit is equipped with an air-through bonder, and the fibers are exposed to one or more heated gas streams, such as air.

[0214] In other embodiments, the bonding unit may comprise a calender bonding unit comprising a pair of coordinating heating rolls, wherein at least one of the rolls has a plurality of raised bonding points on its surface. As previously stated, the bonding points can be used to impart a bonding pattern to at least one surface of the nonwoven fabric. In some embodiments, the calender comprises a pair of coordinating rolls, wherein the first roll has an engraved pattern roll with a plurality of bonding points extending from its surface, and the second roll has a smooth surface or an anvil surface. During bonding, a web of spunbond fibers passes between the pair of coordinating rolls, which are heated to a temperature sufficient to soften at least one polymer component containing filaments that make up the web, so that the softened polymer component fuses and bonds with adjacent filaments in the web to form a bonded nonwoven fabric.

[0215] Similar to the embodiments described above, system 100b may also include an optional pair of cooperative rolls (reference numeral 120 in Figure 2), an optional hot air knife, and a vacuum source 128.

[0216] Embodiments of the present invention may also include multilayer nonwoven fabrics having 2 to 10 layers, for example 2 to 5 layers, and particularly 2 to 3 layers, regardless of whether the spunbond system in Figure 2 or Figure 3 is configured to produce single-component or multi-component fibers. For example, the system may comprise a first spunbond beam, a meltblown beam, and a second spunbond beam, each beam superimposing on a previously deposited nonwoven fabric layer to deposit the nonwoven fabric layer. In this example, the system is configured to produce a nonwoven fabric having a spunbond-meltblown-spunbond (SMS) structure.

[0217] In other embodiments, the process may be configured to produce a wide variety of different multilayered fabrics, including spunbond-spunbond (SS), spunbond-spunbond-meltblown (SSM), spunbond-spunbond-meltblown-spunbond (SSMS), spunbond-spunbond-meltblown-meltblown (SSMM), spunbond-spunbond-meltblown-meltblown-spunbond (SSMMS), spunbond-spunbond-meltblown-meltblown-spunbond-spunbond (SSMMSS), and the like.

[0218] The various layers of the nonwoven fabric may include one or more spunbond layers, one or more carded layers, one or more airlaid layers, one or more meltblown layers, and so on.

[0219] In one embodiment, the adhesive nonwoven fabric may comprise a layer made of single-component filaments and a second layer made of multi-component filaments, such as two-component filaments.

[0220] In embodiments in which the adhesive nonwoven fabric comprises multiple layers, the system may optionally include additional fiber-forming devices. For example, a system according to an embodiment of the present invention may include one or more meltblown beams, one or more devices for preparing carded nonwoven fabric layers, one or more devices for preparing airlaid nonwoven fabric layers, and so on. Such additional devices may be arranged on the same production line as the other fiber-forming devices to provide a continuous system. Alternatively, one or more additional layers may be supplied from a feed roll on which pre-prepared nonwoven fabrics have been wound.

[0221] In one embodiment, the nonwoven fabric may include at least one spunbond layer containing filaments that are not crimped or have low crimping, and at least one layer containing crimped filaments.

[0222] According to one embodiment, for example, bonding a web to form an adhesive nonwoven fabric involves thermally spot-bonding the web using heat and pressure through a calender having a pair of cooperative rolls that include a patterned roll. The patterned roll imparts a three-dimensional geometric bonding pattern to the nonwoven fabric. Various features of the patterned roll are as described above.

[0223] In one embodiment, the nonwoven fabric of the present invention may be combined with one or more additional nonwoven fabric layers to prepare a composite material or a laminate material.

[0224] As previously stated, examples of such composites / laminates include spunbond composites, such as spunbond-meltblown (SM) composites, spunbond-meltblown-spunbond (SMS) composites, or spunbond-meltblown-meltblown-spunbond (SMMS) composites, or spunbond-spunbond-meltblown-meltblown-spunbond (SSMMS) composites, or spunbond-spunbond-meltblown-spunbond (SSMS) composites. In some embodiments, composites comprising one layer of bonded nonwoven fabric and one or more film layers may be prepared. It should be recognized that other configurations also fall within the scope of the present invention.

[0225] For example, Figures 4A to 4D are cross-sectional views of a composite according to a certain embodiment of the present invention. For example, Figure 4A shows a spunbond-meltblown (SM) composite 300 having a spunbond nonwoven fabric layer 310 and a meltblown layer 320 according to an embodiment of the present invention.

[0226] Figure 4B shows a spunbond-meltblown-spunbond (SMS) composite 340 having two spunbond nonwoven fabric layers 342 and a meltblown layer 320 sandwiched between the spunbond nonwoven fabric layers 342.

[0227] Figure 4C shows an SMS composite 360 ​​having a spunbond nonwoven fabric layer 362, a different spunbond layer 364, and a meltblown layer 320 sandwiched between the two spunbond layers 362 and 364.

[0228] Finally, Figure 4D shows a spunbond-meltblown-meltblown-spunbond (SMMS) composite 380 having a spunbond nonwoven fabric layer 382, ​​a different spunbond layer 384, and two meltblown layers 320 sandwiched between the two spunbond layers 382 and 384. Although the SMMS composite 380 is shown having two different spunbond layers 382 and 384, both spunbond layers may consist of the same spunbond nonwoven fabric layer or two different spunbond layers.

[0229] In these multilayer structures, the standard weight of the spunbond nonwoven fabric layer is 5 g / m². 2 From a low value of 150g / m 2 It can be in the range of. In some embodiments, including multilayer structures (e.g., SM, SMS, and SMMS), the amount of meltblown layer in the composite structure can be in the range of about 5 to about 30% by weight, and especially about 5 to about 15% by weight, as a weight percentage of the whole structure.

[0230] It should be recognized that the spunbond layers may be identical or different from each other. In addition, the meltblown layer may contain one or more of the same polymers as the spunbond layers or different polymers.

[0231] In one embodiment including a polypropylene meltblown layer, polypropylene typically having an MFR greater than about 500 g / 10 min may be used. For example, such polypropylene may have an MFR of about 500 to about 2500 g / 10 min, particularly about 1000 to about 1500 g / 10 min, where an MFR of about 1200 to 1400 g / 10 min is somewhat more typical. Examples of such polypropylenes include, for example, H155 (1284 MFR) g / 10 min, available from Braskem; commodity number 1100YC (having an MFR of 1,200 g / 10 min), IPRC Thailand; commodity number HP461Y (having an MFR of 1,300 g / 10 min), Lyonedell Basell, and the like.

[0232] The multilayer structures according to the embodiments can be prepared by various methods, including a continuous in-line process in which each layer is prepared sequentially on the same line, or by depositing a meltblown layer on a pre-formed spunbond layer. The layers of the multilayer structure can be bonded together to form a multilayer composite sheet material using thermal bonding, mechanical bonding, adhesive bonding, hydroentangling, or a combination thereof.

[0233] The multilayer structures according to the embodiments can be prepared in various ways, including a continuous in-line process in which each layer is prepared sequentially on the same line, or by depositing a second nonwoven layer on a pre-formed spunbond layer. The layers of the multilayer structure can be thermally bonded to each other to form a multilayer composite sheet material, providing a composite sheet material having the adhesive pattern described herein. In addition, the composite sheet material, the composite sheet material according to one embodiment of the present invention, may also be subjected to other bonding techniques, such as thermal bonding via air-through dry, mechanical bonding, adhesive bonding, hydroentangling, or a combination thereof. In one embodiment, the layers may be thermally bonded to each other by passing the multilayer structure through a bonding unit equipped with an air-through bonder, such as an oven, where the fibers are exposed to a heated gas stream, such as air.

[0234] In some embodiments, a multilayer structure can be thermally spot-bonded to each other by passing it through an adhesive unit equipped with a pair of calender rolls. The pattern rolls of the calender have an engraved surface on which an adhesive pattern is included.

[0235] In one embodiment, the nonwoven fabric according to the embodiment of the present invention has an adhesive area percentage of about 9.6 to about 14%, and an adhesive area of ​​about 0.10 to about 0.25 mm. 2 The average of the individual bonding areas is approximately 4 to 7.25 mm. -1 It may be characterized by having an average bonding point filling value and possessing one or more of the following characteristics.

[0236] Nonwoven fabrics according to embodiments of the present invention can be used to prepare a variety of different structures. For example, in some embodiments, the adhesive nonwoven fabric of the present invention may consist of about 1 to about 10 layers, particularly 2 to 8 layers, for example 3 to 6 layers.

[0237] As described above, in certain embodiments, the adhesive nonwoven fabric may be combined with one or more additional layers to prepare a composite material or a laminate material.

[0238] Examples of such composites / laminates include spunbond composites, such as spunbond - meltblown (SM) composites, spunbond - meltblown - spunbond (SMS) composites or spunbond - meltblown - meltblown - spunbond (SMMS) composites. In some embodiments, a composite may be prepared that includes one layer of the adhered nonwoven fabric and one or more film layers. It should be recognized that other configurations are also within the scope of the present invention.

[0239] As described above, nonwoven fabrics prepared according to embodiments of the present invention can be used in a wide variety of products and applications. For example, embodiments of the present invention can be used for personal care applications, such as baby care products (diapers, wipes), femcare products (napkins, sanitary napkins, tampons), adult care products (incontinence products), or cosmetic application products (pads), agricultural application products (e.g., root wraps, seed bags, crop covers), industrial application products (e.g., workwear coveralls, airplane pillows, automobile trunk liners, sound insulation materials), and household goods products (e.g., mattress coil covers and furniture scratch pads).

[0240] The following examples are provided to illustrate one or more embodiments of the present invention and should not be construed as limiting the present invention.

[0241] Examples

[0242] Unless otherwise specified, the spunbond nonwoven fabric in the following examples was prepared using a Reicofil 4S spunbond spinning line produced by Reifenhaeuser. Unless otherwise specified, all percentages are by weight. The materials and test methods used in the examples are as follows.

[0243] Test methods:

[0244] The standard weight was measured according to NWSP 130.1.

[0245] The MD tensile strength and CD tensile strength were measured according to NWSP 110.4B (changes: the gauge length was 100 mm, the sample width was 50 mm, and the speed was 100 mm / min).

[0246] The MD elongation and CD elongation were measured according to NWSP 110.4B (changes: the gauge length was 100 mm, the sample width was 50 mm, and the speed was 100 mm / min).

[0247] The air permeability was measured according to ASTM 90.3.

[0248] The hydrohead was measured according to WSP80.6.

[0249] The softness bending was measured according to WSP90.1.

[0250] The fiber fineness (dtex) was measured according to the conventional microscopic method in the prior art.

[0251] Materials

[0252] "PP-1" refers to Ziegler-Natta-catalyzed homopolymer polypropylene with an MFR of 35 g / 10 min, available from IPRC Thailand under product number 1105SC.

[0253] "PP-2" refers to metallocene-catalyzed homopolymer polypropylene with an MFR of 30 g / 10 min, available from Lyondell Basell under product number HM562S.

[0254] "PP-3" refers to meltblown grade polypropylene with an MFR of 1,200 g / 10 min, available from IPRC Thailand under product number 1100YC.

[0255] "PP-4" refers to meltblown grade polypropylene with an MFR of 1,300 g / 10 min, available from Lyondell Basell under product number HP461Y.

[0256] "PP-5" refers to metallocene-catalyzed polypropylene with an MFR of 25 g / 10 min, available from LG under product number MHE1100.

[0257] "EPP" is a trademark of VISTAMAXX 商標 This refers to an elastomeric polyolefin copolymer with an MFR of 48 g / 10 min, available from Exxon Mobil under the 7050 FL standard.

[0258] "L-MODU" is the product name L-MODU 商標 This refers to a low-isotactic polypropylene copolymer available from Idemitsu Kosan Co., Ltd.

[0259] "TiO2" refers to Remafin White PPF2K002G Titanium Dioxide, available from Clariant / Avient under product code PP0N420701.

[0260] "GP" refers to the green pigment available from Standridge under the trade name SCC Green 0087.

[0261] "SA-1" is a trademark of ACCURE. 登録商標 This refers to the slip agent available from Evonik Industries under the name SF 617.

[0262] "SA-2" refers to a slip agent available from Salee Industries, Thailand under the trade name APSA22154.

[0263] Calendar bonding

[0264] In the following embodiment, two different calendering units were used. Both calendering units had an engraved patterned roll and a corresponding anvil roll with a smooth surface. A typical adhesive pattern applied to the surface of a nonwoven fabric by both engraved pattern rolls is shown in Figure 5. Figure 5 shows a nonwoven fabric 500 having an adhesive pattern on its surface 512. The adhesive pattern generally consists of a plurality of spaced bond points 14, which are arranged in a series of alternating arrays consisting of pairs of bond points 520, 522, and 524 extending in the machine direction (MD), transverse direction (CD), and diagonal direction (DD) of the nonwoven fabric. Array pair 520 includes arrays A1 and A2 extending transversely of the nonwoven fabric. Array pair 522 includes arrays A3 and A4 extending in the machine direction. The pair of arrays 524 includes arrays A5 and A6 extending diagonally across the nonwoven fabric. The arrays extending in the machine direction are substantially aligned with respect to the vertical axis (V) of the nonwoven fabric (e.g., 5 ois within, and the array extending in the machine direction is substantially aligned (e.g., within 5°) with the horizontal axis (H) of the nonwoven fabric.

[0265] The calendar bonding unit 1 is provided with a bonded nonwoven fabric having a bond density of 49.9 bond points / cm 2 and each individual bond had a length of 0.882 mm, a width of 0.524 mm, and a bond point surface area of 0.36 mm 2 . The average collective distance between adjacent bond points was 1.19 mm. The distance of the bond points refers to how closely the bond points are arranged relative to the machine direction, transverse direction, and diagonal direction of the nonwoven fabric in a given adhesion pattern. The average bond point distance can be calculated from the average value of the distances between adjacent bond points in adjacent adhesions in the machine direction of the nonwoven fabric (Figure 5, d8), adjacent adhesions in the transverse direction of the nonwoven fabric (Figure 5, d7), and adjacent adhesions in the diagonal direction of the nonwoven fabric (Figure 5, d9). The average bond point packing value for the adhesion pattern was 3.30 mm -1 . The average bond point packing value for a given adhesion pattern is calculated by dividing the total average distance of the bond points for the adhesion pattern by the average surface area of the bond points.

[0266] The calendar bonding unit 2 is provided with a bonded nonwoven fabric having a bond density of 33.4 bond points / cm 2 and each individual bond had a length of 1.09 mm, a width of 0.47 mm, and a bond point surface area of 0.4 mm 2 . The average collective distance between adjacent bond points was 1.6 mm. The average bond point packing value for the adhesion pattern was 4 mm-1 That was the case.

[0267] The calendar bonding unit 3 has 55.4 bond points per cm. 2 A bonded nonwoven fabric having a bond density is provided, with each bond being 0.76 mm in length, 0.30 mm in width, and 0.18 mm in length. 2 The bond point surface area was as follows: The average collective distance between adjacent bond points was 1.28 mm. The average bond point packing for this adhesive pattern was 7.11 mm. -1 That was the case.

[0268] Comparative Example 1

[0269] In Comparative Example 1, a multilayer nonwoven fabric having a spunbond-meltblown-spunbond (SMS) structure was prepared. The spunbond layer consisted of filaments made from a blend of 89.9 wt percent PP-1 and 0.1 wt percent TiO2. The meltblown layer consisted of meltblown fibers made from PP-4. The spunbond layer constituted 90 wt percent of the nonwoven fabric. The spunbond filaments of the spunbond layer were spun at a cabin pressure of approximately 3,300 to 3,500 Pa and a polymer throughput of 2,750 kg / hour.

[0270] The extruded filaments were collected on a moving collection surface, and the resulting multilayer nonwoven fabric was thermally spot-bonded by the calender bonding unit 1. The patterned roll was heated to a temperature of approximately 152°C. In Comparative Example 1, the surface area of ​​the bonded nonwoven fabric was 18.1%, and the bonding density was 1 cm². 2 There were 49.9 adhesive points per unit.

[0271] Example 1 of the present invention

[0272] In Example 1 of the present invention, a multilayer nonwoven fabric was prepared in the same manner as in Comparative Example 1, except for the die cabin pressure and the polymer composition of the spunbond layer. Similar to Comparative Example 1, the nonwoven fabric of Example 1 of the present invention had an SMS structure. The spunbond layer consisted of filaments made from a blend containing 79.0 weight percent PP-1, 10 weight percent EPP, 0.5 weight percent TiO2, and 0.5 weight percent SA-2. The meltblown layer consisted of meltblown fibers made of PP-3. In total, the spunbond layer constituted 90 weight percent of the nonwoven fabric. The spunbond filaments of the spunbond layer were spun at a cabin pressure of approximately 4,500 to 4,700 Pa and a polymer throughput of 2,450 kg / hour.

[0273] The multilayer nonwoven fabric of Example 1 of the present invention was thermally spot-bonded using a calendering unit 1 under the same conditions as Comparative Example 1.

[0274] Comparative Example 2

[0275] In Comparative Example 2, the multilayer nonwoven fabric had the same SMS structure as in Comparative Example 1. The spunbond layer consisted of filaments made from a blend of 89.9 weight percent PP-1 and 0.1 weight percent TiO2. The meltblown layer consisted of meltblown fibers made from PP-4. In total, the spunbond layer constituted 90 weight percent of the nonwoven fabric. The spunbond filaments of the spunbond layer were spun at a die cabin pressure of approximately 3,300–3,500 Pa and a polymer throughput of 2,750 kg / hour.

[0276] The nonwoven fabric of Comparative Example 2 was thermally spot-bonded using adhesive calendering unit 2. The calendering unit was operated at a temperature of approximately 152°C. The percentage of the bonded nonwoven fabric surface in Comparative Example 2 was approximately 13.4%, and the bonding density was 1 cm². 2There were 33.4 adhesive points per unit.

[0277] Example 2 of the present invention

[0278] In Example 2 of the present invention, a multilayer nonwoven fabric was prepared in the same manner as in Comparative Example 2, except for the die cabin pressure and the polymer composition of the spunbond layer. Similar to Comparative Example 2, the nonwoven fabric of Example 2 of the present invention had an SMS structure. The spunbond layer consisted of filaments made from a blend containing 71.4% by weight of PP-1, 18% by weight of L-MODU, 0.3% by weight of TiO2, and 0.3% by weight of SA-1. The meltblown layer consisted of meltblown fibers made of PP-4. In total, the spunbond layer constituted 90% by weight of the nonwoven fabric. The spunbond filaments of the spunbond layer were spun at a cabin pressure of approximately 4,400 to 4,600 Pa and a polymer throughput of 2,450 kg / m / hour.

[0279] The multilayer nonwoven fabric of Example 2 of the present invention was thermally spot-bonded using the same calendering unit 2 under the same conditions as in Comparative Example 2.

[0280] Comparative Examples 1 and 2, as well as the nonwoven fabrics of Examples 1 and 2 of the present invention, were evaluated for their mechanical properties, physical properties, flexibility, and filament fineness. The results are summarized in Table 1 below.

[0281] [Table 1] The values ​​shown in Table 1 are based on the average of 10 samples.

[0282] Tables 1 and 2 clearly show that, compared to nonwoven fabrics prepared under identical conditions except for the absence of the elastomerous polyolefin and the filaments being stretched and fined at a cabin pressure of less than 4,200 Pa, improvements in flexibility and fiber fineness are accompanied by a slight decrease or no decrease at all in mechanical properties. In some embodiments, the nonwoven fabrics of the present invention showed improvements in both tensile strength and elongation.

[0283] For example, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and refined at a cabin pressure of less than 4,200 Pa, the MD tensile strength and CD tensile strength showed an increase in the range of about 2 to about 15%. Only Example 1 of the present invention showed a decrease in mechanical properties (a 2.7% decrease in CD tensile strength compared to Comparative Example 1), while all other properties showed an increase.

[0284] Both Examples 1 and 2 of the present invention showed an increase of approximately 5 to approximately 30% in the mechanical direction (MD) or transverse direction (CD) elongation percentage, or both, compared to Comparative Examples 1 and 2. In particular, Example 1 of the present invention showed a 15.3 percent increase in MD elongation percentage and a 26.1 percent increase in CD elongation percentage.

[0285] [Table 2]

[0286] [Table 3]

[0287] In Table 1, the MD tensile strength and CD tensile strength were similar between the comparative example and the corresponding example of the present invention, with the example of the present invention showing generally modest improvement. Both Example 1 and Example 2 of the present invention showed increases in both MD elongation and CD elongation compared to the comparative example.

[0288] Regarding Table 2, the embodiments of the present invention obtained by subdividing the fibers during the stretching and finening stages demonstrated improved flexibility. In particular, both embodiments of the present invention showed a significant decrease in bending length, which means that the nonwoven fabrics were softer compared to the nonwoven fabrics of Comparative Examples 1 and 2. Considering this in conjunction with the mechanical process, it can be seen that improvements in flexibility are obtained by incorporating elastomeric polyolefins and stretching the filaments under cabin pressures exceeding 4,200 Pa.

[0289] Examples 3 and 4 of the present invention

[0290] In Examples 3 and 4 of the present invention, a three-layer spunbond nonwoven fabric was prepared, each layer comprising the same polymer blend. The nonwoven fabric was thermally spot-bonded using a calendering unit 3 operating at a temperature of approximately 150°C. In Examples 2 and 3 of the present invention, the surface percentage of the bonded nonwoven fabric was 9.92%, and the bonding density was 1 cm². 2 There were 55.4 adhesion points per unit area. The nonwoven fabric of Example 3 of the present invention was prepared with a polymer throughput of 180 kg / m / hour and a cabin pressure of 5,100 Pa. The nonwoven fabric of Example 4 of the present invention was prepared with a polymer throughput of 160 kg / m / hour and a cabin pressure of 5,300 Pa.

[0291] The fibers of Examples 3 and 4 of the present invention consisted of a blend of 92.2% PP-2, 7.0% EPP, 0.8% TiO2, and SA-1.

[0292] Example 5 of the present invention

[0293] In the following Example 5 of the present invention, a three-layer spunbond nonwoven fabric was prepared using a calendering unit 2. The system was operated at a cabin pressure exceeding 5,100 Pa and a polymer throughput of 200 kg / m / hour.

[0294] The fibers in Example 5 of the present invention consisted of a blend of 81.4% PP-1, 18.0% L-MODU, 0.8% TiO2, and SA. The calendering unit was operated at a temperature of approximately 150°C. The surface area of ​​the bonded nonwoven fabric in Example 5 of the present invention was 13.4%, and the bonding density was 1 cm². 2 There were 33.4 adhesive points per unit.

[0295] The properties of the nonwoven fabrics in Examples 3-4 of the present invention are shown in Table 4 below.

[0296] [Table 4]

[0297] [Table 5]

[0298] Interestingly, a comparison of Examples 2 and 3 revealed that a decrease in throughput and an increase in cabin pressure resulted in finer fibers. Specifically, the fibers of Example 3 of the present invention exhibited an average filament fineness of 1.26 dtex, while the fibers of Example 4 of the present invention exhibited an average filament size of 0.9 dtex. This represents a 28.6% decrease in fiber fineness.

[0299] Example 6 of the present invention (L5(e-4))

[0300] In Example 6 of the present invention, a nonwoven fabric containing three spunbond layers was prepared using a Reicofil 5 spunbond spinning line manufactured by Reifenhaeuser. The three spunbond layers were sequentially deposited in a continuous in-line process, overlapping each other.

[0301] The fiber was a two-component fiber having a sheath / core structure, in which the fiber sheath consisted of 64 wt percent PP-1, 20 wt percent PP-5, 15.0 wt percent EPP, 0.5 wt percent TiO2, and 0.5 wt percent SA-1, and the core consisted of 69 wt percent PP-1, 30 wt percent PP-5, 0.5 wt percent TiO2, and 0.5 wt percent SA-1. The resulting three layers of nonwoven fabric were thermally bonded using a calender bonding unit 3. The system cabin pressure was operated at 4,500–4,700 Pa with a polymer throughput of 2,960 kg / hour.

[0302] [Table 6]

[0303] [Table 7]

[0304] Furthermore, Example 6 of the present invention, along with the elastomeric polyolefin, consisted of a polymer blend of metallocene-catalyzed polypropylene and Ziegler-Natta-catalyzed polypropylene, and showed a significant improvement in fiber fineness and flexibility, as demonstrated by flexibility bending tests. In fact, the nonwoven fabric had a lower average MD / CD bending value than that of Examples 1 and 2 of the present invention. Elongation also increased, as shown in Table 6.

[0305] Typical Embodiments

[0306] The following representative embodiments are provided to highlight the features of the disclosed nonwoven fabric. It should be noted that the representative embodiments may include one or more combinations of the features described below, or that the representative embodiments may not include all of the features provided.

[0307] In one embodiment, a nonwoven fabric is provided comprising a plurality of fibers bonded together to form a coherent web, wherein the plurality of fibers comprise a polymer blend of a polypropylene resin and an elastomeric polyolefin, wherein the nonwoven fabric exhibits a reduction in fiber fineness of at least 5% compared to a nonwoven fabric prepared under the same conditions without the polypropylene resin and the elastomeric polyolefin blend.

[0308] In one such embodiment, the polypropylene resin of the nonwoven fabric has a molecular weight in any of the following ranges: 120,000 to 300,000 g / mol, 140,000 g / mol to about 280,000 g / mol, about 150,000 to about 250,000 g / mol, and particularly about 160,000 to about 180,000 g / mol. In one embodiment, the polypropylene resin comprises Ziegler-Natta catalyzed polypropylene, metallocene catalyzed polypropylene, or a blend thereof. In some embodiments, the polypropylene resin has a melting point of about 150°C to about 175°C.

[0309] In one embodiment of the nonwoven fabric, the polypropylene resin is present in the polymer blend in an amount of about 75 to about 99 weight percent, particularly about 80 to about 95 weight percent, and more particularly about 85 to about 94 weight percent, based on the total weight of the polymer blend.

[0310] In one embodiment of the nonwoven fabric, the elastomeric polypropylene is present in the polymer blend in an amount ranging from about 2 to about 30 weight percent, particularly 5 to 25 weight percent, and more particularly 8 to about 20 weight percent, based on the total weight of the polymer blend.

[0311] In one embodiment, the elastomeric polyolefin is selected from the group consisting of propylene-alpha-olefin copolymers and low-isotactic polypropylene polymers. For example, the elastomeric polyolefin includes propylene-alpha-olefin copolymers or low-isotactic polypropylene polymers.

[0312] In one embodiment, the elastomeric polyolefin includes low isotactic polypropylene having an isotactic degree [mmmm] of about 20 to about 70 mol%, particularly 30 to 60 mol% [mmmm], and more particularly 35 to 55 mol% [mmmm]. In one embodiment, the low isotactic polypropylene is Isotacticity: 20-70 mol% mesopentad fraction [mmmm]; Number-average molecular weight (Mw) between 10,000 and 200,000; A melting point of approximately 60 to 120°C; and, Melt flow rate (MFR) exceeding 40g / 10 minutes It possesses the following characteristics.

[0313] In one embodiment, the nonwoven fabric comprises fibers having an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex.

[0314] In one embodiment, the fibers of the nonwoven fabric are stretched and refined in a cabin pressure greater than 4,200 Pa, and the nonwoven fabric exhibits a fiber dtex percentage reduction of about 5 to about 30% compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined in a cabin pressure of less than 4,200 Pa.

[0315] In one embodiment, the nonwoven fabric exhibits a reduction of approximately 15-25% in fiber dtex percentage compared to a nonwoven fabric prepared under identical conditions, except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0316] In one embodiment, the nonwoven fabric has mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm.

[0317] In one embodiment, the nonwoven fabric has an average mechanical / transverse bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm.

[0318] In one embodiment, the nonwoven fabric fibers are stretched and finely processed in a cabin exceeding 4,200 Pa, and, The nonwoven fabric is a. Compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa, the nonwoven fabric exhibits a percentage reduction in mechanical directional bending flexibility of approximately 20-40%, particularly about 25-35%, and more particularly about 26-32%, and, b. Percentage reduction in mechanical / transverse bending flexibility, which is about 20-40%, particularly about 20-35%, and more particularly about 22-30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa. This indicates.

[0319] In one embodiment, the nonwoven fabric exhibits a percentage reduction in mechanical bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0320] In one embodiment, the nonwoven fabric exhibits a percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0321] In one embodiment, the nonwoven fabric exhibits one or more of the following characteristics: a) Average fiber fineness in the range of approximately 0.8 to 1.6 dtex, particularly approximately 0.9 to 1.4 dtex, and more particularly approximately 1.2 to 1.35 dtex; b) The nonwoven fabric exhibits a percentage reduction in fiber dtex of approximately 5 to approximately 60%, for example, a percentage reduction in fiber dtex of 15 to 50%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; c) The nonwoven fabric exhibits mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm; d) The nonwoven fabric exhibits one or more machine direction flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more transverse direction flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm; e) exhibiting at least one of the following mechanical directional flexibility: at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm, and at least 48 mm, and at least one of the following lateral flexibility: at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm, and at least 50 mm; f) Average mechanical direction / lateral bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm, for example, one or more of the average mechanical direction / lateral bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / lateral bending flexibility is one or more of the following: less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm. g) A percentage reduction in mechanical directional bending flexibility of about 20-40%, particularly about 25-35%, and more particularly about 26-32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; h) An average percentage reduction in mechanical / transverse bending flexibility of about 20-40%, particularly about 20-35%, and more particularly about 22-30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; i) An average percentage reduction in mechanical / transverse bending flexibility of at least one of the following: at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; j) An average percentage reduction in mechanical / transverse bending flexibility of less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and finely divided at a cabin pressure of less than 4,200 Pa; k) An increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; and, l) An increase in elongation percentage in one or more of the machine direction or transverse direction, ranging from about 5 to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0322] In one embodiment, the nonwoven fabric has an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex.

[0323] In one embodiment, the nonwoven fabric has a percentage reduction in fiber dtex of about 5 to about 30%, for example, a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0324] In one embodiment, the nonwoven fabric has mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm, for example, having mechanical bending flexibility in the range of 35 to 45 mm and transverse bending flexibility in the range of 25 to 40 mm.

[0325] In one embodiment, the nonwoven fabric has mechanical flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and transverse flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm.

[0326] In one embodiment, the nonwoven fabric has a mechanical bending flexibility of at least one of the following: less than 30 mm, less than 32 mm, less than 34 mm, less than 36 mm, less than 38 mm, less than 40 mm, less than 42 mm, less than 46 mm, and less than 48 mm, and a transverse flexibility of at least one of the following: less than 20 mm, at least less than 24 mm, at least less than 26 mm, at least less than 28 mm, at least less than 30 mm, at least less than 32 mm, at least less than 34 mm, at least less than 36 mm, at least less than 38 mm, less than 40 mm, less than 42 mm, less than 44 mm, less than 46 mm, less than 48 mm, and less than 50 mm.

[0327] In one embodiment, the nonwoven fabric has an average mechanical direction / transverse bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm, for example, one or more of the average mechanical direction / transverse bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / transverse bending flexibility is one or more of the following: less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm.

[0328] In one embodiment, the nonwoven fabric has a percentage reduction in mechanical bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0329] In one embodiment, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0330] In one embodiment, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40% compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0331] In one embodiment, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of one or more of the following: less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0332] In one embodiment, the nonwoven fabric has an increase in MD tensile strength and CD tensile strength ranging from about 2 to about 15% compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0333] In one embodiment, the nonwoven fabric has an increase in elongation percentage of 1 or more in the mechanical or transverse direction, ranging from about 5 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0334] In one embodiment, the nonwoven fabric has the following: The average fiber fineness ranges from approximately 0.8 to 1.6 dtex, particularly 0.9 to 1.4 dtex, and more specifically 1.2 to 1.35 dtex; Compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa, there is a percentage reduction in fiber dtex of about 5 to about 30 percent, for example, a percentage reduction in fiber dtex of 15 to 25 percent; and, Mechanical bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm.

[0335] In one embodiment, the nonwoven fabric includes a spunbond layer.

[0336] In one embodiment, the plurality of fibers of the nonwoven fabric have a sheath / core structure, where the polymer blend constitutes the core and the bio-based polymer constitutes the sheath. In some embodiments, the bio-based polymer includes bio-based polyethylene.

[0337] In one embodiment, the nonwoven fabric comprises a first spunbond layer having low crimping filaments or no crimping filaments, and a second layer having crimped filaments.

[0338] In one embodiment, the nonwoven fabric comprises at least two layers, one of which is selected from the group consisting of a meltblown layer, a carded nonwoven fabric layer, a spunbond layer, a resin-bonded layer, an airlaid nonwoven fabric layer, and a spunlace layer.

[0339] In one embodiment, the nonwoven fabric is an absorbent article.

[0340] In one embodiment, the aspects of this disclosure are directed toward nonwoven fabric products, including the aforementioned nonwoven fabrics.

[0341] A perspective of the present invention also relates to composite sheet materials including the aforementioned nonwoven fabrics. In some embodiments, the sheet material includes a meltblown layer, for example, an embodiment in which the meltblown layer is sandwiched between two spunbond layers.

[0342] The aspect of this disclosure is a method for preparing an adhesive nonwoven fabric, A first polypropylene resin and an elastomeric polyolefin are melt-mixed to form a molten or semi-molten polymer flow of the polymer blend; Introducing the polymer flow into a spinning beam; The polymer flow is extruded from the spinning beam to form fibers; The formed fibers are subjected to a cabin pressure exceeding 4,200 Pa to stretch and thin them; and, The method involves gathering the fibers on a collection surface to form a nonwoven web, wherein the plurality of fibers exhibit an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex, and the nonwoven shows a percentage reduction in fiber dtex of about 5 to about 30%, for example, a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven prepared under identical conditions except that it does not contain the elastomeric polyolefin and the fibers are stretched and finened at a cabin pressure of less than 4,200 Pa. The above method is intended.

[0343] In one embodiment, the fibers are stretched and finely processed at a cabin pressure ranging from about 4,500 to about 7,500 Pa, particularly from about 5,500 to about 7,500 Pa.

[0344] In one embodiment of this method, the first polypropylene has a molecular weight ranging from 120,000 to 300,000 g / mol, 140,000 g / mol to about 280,000 g / mol, about 150,000 to about 250,000 g / mol, and particularly about 160,000 to about 180,000 g / mol. In some embodiments, the first polypropylene includes Ziegler-Natta catalyzed polypropylene, metallocene catalyzed polypropylene, or a blend thereof. In one embodiment, the polypropylene resin has a melting point of about 150°C to about 175°C.

[0345] In one embodiment, the first polypropylene is present in the polymer blend in an amount of about 75 to about 99 weight percent, particularly about 80 to 95 weight percent, and more particularly about 85 to 94 weight percent, based on the total weight of the polymer blend. In another embodiment, the elastomeric polypropylene is present in the polymer blend in an amount ranging from about 2 to about 30 weight percent, particularly 5 to 25 weight percent, and more particularly about 8 to about 20 weight percent, based on the total weight of the polymer blend.

[0346] In one embodiment, the elastomeric polyolefin comprises a propylene-alpha-olefin copolymer. In another embodiment, the elastomeric polyolefin comprises a low-isotactic polypropylene polymer.

[0347] In one embodiment, the low isotactic polypropylene has an isotactic degree [mmmm] of about 20 to about 70 mol%, particularly 30 to 60 mol% [mmmm], and more particularly 35 to 55 mol% [mmmm].

[0348] In one embodiment, the low-isotactic polypropylene has the following properties: Isotacticity: Mesopentad fraction of 20-70 mol% [mmmm]; Number-average molecular weight (Mw) between 10,000 and 200,000; A melting point of approximately 60 to 120°C; and, Melt flow rate (MFR) exceeding 40g / 10 minutes.

[0349] In one embodiment of this method, the nonwoven fabric comprises fibers having an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex.

[0350] In one embodiment of this method, the nonwoven fabric exhibits a percentage reduction of approximately 5 to 60% in fiber dtex compared to a nonwoven fabric prepared under identical conditions, except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0351] In one embodiment of this method, the nonwoven fabric exhibits a fiber dtex percentage reduction of approximately 15 to 60%, for example, 15 to 25%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0352] In one embodiment of this method, the nonwoven fabric has mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm.

[0353] In one embodiment of this method, the nonwoven fabric has an average mechanical / transverse bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm.

[0354] In one embodiment of this method, the nonwoven fabric exhibits a percentage reduction in mechanical bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0355] In one embodiment of this method, the nonwoven fabric exhibits a percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0356] In one embodiment of this method, the nonwoven fabric exhibits one or more of the following characteristics: a) Average fiber fineness in the range of approximately 0.8 to 1.6 dtex, particularly approximately 0.9 to 1.4 dtex, and more particularly approximately 1.2 to 1.35 dtex; b) A percentage reduction of approximately 5 to approximately 60% in fiber dtex, for example, 15 to 50% in fiber dtex, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; c) Mechanical direction bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm; d) One or more mechanical directional flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more mechanical directional bending flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm; e) at least one of the following mechanical directional flexibility: at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm and at least 48 mm, and at least one of the following lateral flexibility: at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm; f) Average mechanical direction / lateral bending flexibility in the range of 25-40 mm, particularly about 28-38 mm, for example, one or more of the average mechanical direction / lateral bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / lateral bending flexibility is one or more of the following: less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm; g) A percentage reduction in mechanical directional bending flexibility of about 20-40%, particularly about 25-35%, and more particularly about 26-32%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; h) An average percentage reduction in mechanical / transverse bending flexibility of about 20-40%, particularly about 20-35%, and more particularly about 22-30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; i) An average percentage reduction in mechanical direction / transverse bending flexibility of at least one of the following percentages, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa: at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40%; j) An average percentage reduction in mechanical / transverse bending flexibility of less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and finely divided at a cabin pressure of less than 4,200 Pa; k) An increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; and, l) An increase in elongation percentage of 1 or more in the mechanical or transverse direction, ranging from about 5 to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0357] In one embodiment of this method, the nonwoven fabric has an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex.

[0358] In one embodiment of this method, the nonwoven fabric exhibits a percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain elastomer polyolefins and is stretched and refined at a cabin pressure of less than 4,200 Pa.

[0359] In one embodiment of the present method, the nonwoven fabric has a percentage reduction in fiber dtex of about 5 to about 30%, for example, a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0360] In one embodiment of this method, the nonwoven fabric has mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm.

[0361] In one embodiment of the present method, the nonwoven fabric has one or more machine-direction flexibilitys among less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more transverse flexibilitys among less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm.

[0362] In one embodiment of the present method, the nonwoven fabric has a machine direction flexibility of at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm and at least 48 mm, and a transverse direction flexibility of at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm.

[0363] In one embodiment of the present method, the nonwoven fabric has an average mechanical direction / transverse bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm, for example, one or more of the average mechanical direction / transverse bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, wherein the average mechanical direction / transverse bending flexibility is one or more of the following: less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm.

[0364] In one embodiment of the present method, the nonwoven fabric has a percentage reduction in mechanical bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0365] In one embodiment of the present method, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0366] In one embodiment of the present method, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40% compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0367] In one embodiment of the present method, the nonwoven fabric has an average percentage reduction in mechanical / transverse bending flexibility of one or more of the following: less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

[0368] In one embodiment of this method, the nonwoven fabric has MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0369] In one embodiment of the present method, the nonwoven fabric has an increase in elongation percentage in one or more of the mechanical or transverse directions, ranging from about 5 to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomeric polyolefin and the filaments are stretched and refined at a cabin pressure of less than 4,200 Pa.

[0370] In one embodiment of this method, the nonwoven fabric has the following: Approximately 0.8 to 1.6 dtex, especially approximately 0.9 to 1.4 dtex, and more specifically approximately 1.2 to 1.35 dtex. Average fiber fineness within the range; Compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa, there is a percentage reduction in fiber dtex of about 5 to about 360%, for example, a percentage reduction in fiber dtex of 15 to 25%; and, Mechanical bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm, for example, mechanical bending flexibility in the range of 35-45 mm and lateral bending flexibility in the range of 25-40 mm.

[0371] In one embodiment of this method, the nonwoven web includes a spunbond web.

[0372] In one embodiment of the present method, the method further includes depositing a second fabric layer on top of the nonwoven web. In some embodiments, the second fabric layer is selected from the group consisting of a meltblown layer, a carded nonwoven layer, a spunbond layer, a resin-bonded layer, an airlaid nonwoven layer, and a spunlace layer.

[0373] In one embodiment of the present method, the method further includes a step of heat-bonding the nonwoven web. In some embodiments, the step of heat-bonding the nonwoven web includes calendering the nonwoven web using a carved roll having raised adhesive points configured and positioned to impart an adhesive pattern to the surface of the nonwoven web, the adhesive pattern having an adhesive area percentage of about 9.6 to about 14% and about 0.10 to about 0.25 mm 2 The average of the individual bonding surface areas, and approximately 4 to 7.25 mm -1 It has an average adhesion point filling value.

[0374] The perspective of this disclosure is also directed toward using this method to prepare absorbent articles.

Claims

1. A nonwoven fabric comprising a plurality of fibers bonded together to form a coherent web, wherein the plurality of fibers comprise a polymer blend of a polypropylene resin and an elastomeric polyolefin, wherein the nonwoven fabric exhibits a reduction in fiber fineness of at least 5% compared to a nonwoven fabric prepared under the same conditions without the polypropylene resin and the elastomeric polyolefin blend.

2. The nonwoven fabric according to claim 1, wherein the polypropylene resin has a molecular weight in the range of 120,000 to 300,000 g / mol, a melting point of about 150°C to about 175°C, and the polypropylene resin comprises Ziegler-Natta catalyzed polypropylene, metallocene catalyzed polypropylene, or a blend thereof.

3. The nonwoven fabric according to claim 1 or 2, wherein the elastomerized polypropylene is present in the polymer blend in an amount ranging from about 2 to about 30 weight percent based on the total weight of the polymer blend.

4. The nonwoven fabric according to any one of claims 1 to 3, wherein the elastomerous polyolefin is selected from the group consisting of propylene-alpha-olefin copolymer and low isotactic polypropylene polymer.

5. The low-isotactic polypropylene is Isotacticity: 20–70 mol% mesopentad fraction [mmmm]; Number-average molecular weight (Mw) between 10,000 and 200,000; A melting point of approximately 60 to 120°C; and, Melt flow rate (MFR) exceeding 40g / 10 minutes The nonwoven fabric according to claim 4, having the characteristics described.

6. The nonwoven fabric according to any one of claims 1 to 5, wherein the nonwoven fabric contains fibers having an average fiber fineness in the range of about 0.8 to about 1.6 dtex.

7. The nonwoven fabric according to any one of claims 1 to 6, wherein the nonwoven fabric exhibits a reduction of approximately 5 to approximately 30% in fiber dtex percentage compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and is stretched and refined at a cabin pressure of less than 4,200 Pa.

8. The nonwoven fabric according to any one of claims 1 to 7, wherein the nonwoven fabric has mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm.

9. The nonwoven fabric according to any one of claims 1 to 8, wherein the nonwoven fabric has an average mechanical / transverse bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm.

10. The aforementioned nonwoven fabric fibers are stretched and finely processed in a cabin exceeding 4,200 Pa, and, The aforementioned nonwoven fabric, a) Compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa, there is a percentage reduction in mechanical direction bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, and, b) A percentage reduction in mechanical / transverse bending flexibility of approximately 20-40%, particularly about 20-35%, and more particularly about 22-30%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa. A nonwoven fabric according to any one of claims 1 to 9, which shows the above.

11. The aforementioned nonwoven fabric fibers are stretched and finely processed in a cabin exceeding 4,200 Pa, and, The aforementioned nonwoven fabric, The average fiber fineness (m) ranges from approximately 0.8 to 1.6 dtex, particularly 0.9 to 1.4 dtex, and more specifically 1.2 to 1.35 dtex; n) The nonwoven fabric exhibits a percentage reduction in fiber dtex of approximately 5 to approximately 60%, for example, a percentage reduction in fiber dtex of 15 to 50%, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; o) The nonwoven fabric exhibits mechanical bending flexibility in the range of 30 to 50 mm and transverse bending flexibility in the range of 15 to 40 mm; p) The nonwoven fabric exhibits one or more mechanical directional flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more transverse directional flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm; q) exhibiting at least one mechanical directional flexibility of at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm and at least 48 mm, and at least one lateral flexibility of at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm; r) Average mechanical direction / lateral bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm, for example, one or more of the average mechanical direction / lateral bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / lateral bending flexibility is one or more of the following: less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm; s) A percentage reduction in mechanical directional bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; t) An average percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; u) An average percentage reduction in mechanical / transverse bending flexibility of at least one of the following percentages, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa: at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40%; v) An average percentage reduction in mechanical / transverse bending flexibility of less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and finely divided at a cabin pressure of less than 4,200 Pa; w) An increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; and, x) An increase in elongation percentage in one or more of the machine direction or transverse direction, ranging from about 5% to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa. A nonwoven fabric according to any one of claims 1 to 10, exhibiting one or more of the characteristics among them.

12. The nonwoven fabric according to any one of claims 1 to 11, wherein the nonwoven fabric has an increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

13. The nonwoven fabric according to any one of claims 1 to 12, wherein the nonwoven fabric has an increase in elongation percentage in one or more directions, either mechanical or transverse, ranging from about 5 to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa.

14. The aforementioned nonwoven fabric, The average fiber fineness ranges from approximately 0.8 to 1.6 dtex, particularly 0.9 to 1.4 dtex, and more specifically 1.2 to 1.35 dtex; Compared to a nonwoven fabric prepared under the same conditions except that it does not contain the aforementioned elastomerized polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa, there is a percentage reduction in fiber dtex of approximately 5 to approximately 30%, for example, a percentage reduction in fiber dtex of 15 to 25%; and, Mechanical direction bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm A nonwoven fabric according to any one of claims 1 to 13, having the following characteristics.

15. The nonwoven fabric according to any one of claims 1 to 14, wherein the nonwoven fabric includes a spunbond layer.

16. An absorbent article comprising a nonwoven fabric as described in any one of claims 1 to 15.

17. A method for preparing an adhesive nonwoven fabric, A first polypropylene resin and an elastomeric polyolefin are melt-mixed to form a molten or semi-molten polymer flow of a polymer blend; Introducing the polymer flow into the spinning beam; The polymer flow is extruded from the spinning beam to form fibers; The formed fibers are subjected to a cabin pressure exceeding 4,200 Pa to stretch and thin them; and, The method involves gathering the fibers on a collection surface to form a nonwoven web, wherein the fibers exhibit an average fiber fineness in the range of about 0.8 to about 1.6 dtex, particularly about 0.9 to about 1.4 dtex, and more particularly about 1.2 to about 1.35 dtex, and the nonwoven shows a percentage reduction in fiber dtex of about 5 to about 30%, for example, a percentage reduction in fiber dtex of 15 to 25%, compared to a nonwoven prepared under the same conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa. The method, including the method described above.

18. The method according to claim 17, wherein the cabin pressure is in the range of about 4,500 to about 7,500 Pa, and more particularly, about 5,500 to about 7,500 Pa.

19. The method according to claim 18 or 19, wherein the elastomerous polyolefin comprises a propylene-alpha-olefin copolymer or a low-isotactic polypropylene polymer.

20. The aforementioned nonwoven fabric, The average fiber fineness (m) ranges from approximately 0.8 to 1.6 dtex, particularly 0.9 to 1.4 dtex, and more specifically 1.2 to 1.35 dtex; n) A percentage reduction in fiber dtex of approximately 5 to approximately 60%, for example, 15 to 25%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; o) Mechanical bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm; p) One or more mechanical directional flexibility of less than 50 mm, less than 48 mm, less than 46 mm, less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, and less than 30 mm, and one or more lateral flexibility of less than 44 mm, less than 42 mm, less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm, and less than 20 mm; q) exhibiting at least one mechanical bending flexibility among at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 46 mm and at least 48 mm, and at least one lateral bending flexibility among at least 20 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm, at least 40 mm, at least 42 mm, at least 44 mm, at least 46 mm, at least 48 mm and at least 50 mm; r) Average mechanical direction / lateral bending flexibility in the range of 25 to 40 mm, particularly about 28 to about 38 mm, for example, one or more of the average mechanical direction / lateral bending flexibility of at least 20 mm, at least 22 mm, at least 24 mm, at least 26 mm, at least 28 mm, at least 30 mm, at least 32 mm, at least 34 mm, at least 36 mm, at least 38 mm and at least 40 mm, where the average mechanical direction / lateral bending flexibility is one or more of the following: less than 40 mm, less than 38 mm, less than 36 mm, less than 34 mm, less than 32 mm, less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, less than 22 mm and less than 20 mm; s) A percentage reduction in mechanical directional bending flexibility of about 20 to about 40%, particularly about 25 to about 35%, and more particularly about 26 to about 32%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; t) An average percentage reduction in mechanical / transverse bending flexibility of about 20 to about 40%, particularly about 20 to about 35%, and more particularly about 22 to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; u) An average percentage reduction in mechanical / transverse bending flexibility of at least one of the following percentages, compared to a nonwoven fabric prepared under identical conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa: at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 32%, at least 34%, at least 36%, at least 38%, and at least 40%; v) An average percentage reduction in mechanical / transverse bending flexibility of less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, and less than 12%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomer polyolefin and the fibers are stretched and finely divided at a cabin pressure of less than 4,200 Pa; w) An increase in MD tensile strength and CD tensile strength in the range of about 2 to about 15% compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and finely processed at a cabin pressure of less than 4,200 Pa; and, x) An increase in elongation percentage in one or more of the machine direction or transverse direction, ranging from about 5% to about 30%, compared to a nonwoven fabric prepared under the same conditions except that it does not contain the elastomerous polyolefin and the fibers are stretched and refined at a cabin pressure of less than 4,200 Pa. The method according to any one of claims 18 to 20, which exhibits one or more of the characteristics among them.

21. The aforementioned nonwoven fabric, The average fiber fineness ranges from approximately 0.8 to 1.6 dtex, particularly 0.9 to 1.4 dtex, and more specifically 1.2 to 1.35 dtex; Compared to a nonwoven fabric prepared under the same conditions except that it does not contain the aforementioned elastomerous polyolefin and the filaments are stretched and finely divided at a cabin pressure of less than 4,200 Pa, there is a percentage reduction in fiber dtex of approximately 5 to approximately 360%, for example, a percentage reduction in fiber dtex of 15 to 25%; and, Mechanical direction bending flexibility in the range of 30-50 mm and lateral bending flexibility in the range of 15-40 mm, for example, mechanical direction bending flexibility in the range of 35-45 mm and lateral bending flexibility in the range of 25-40 mm The method according to any one of claims 17 to 20, comprising:

22. The method according to any one of claims 17 to 21, further comprising depositing a second fabric layer above the nonwoven web, wherein the second fabric layer is selected from the group consisting of a meltblown layer, a carded nonwoven layer, a spunbond layer, a resin-bonded layer, an airlaid nonwoven layer, and a spunlace layer.

23. The method according to any one of claims 17 to 22, further comprising the step of heat-bonding the nonwoven web.

24. The process of heat-bonding the nonwoven web includes calendering the nonwoven web using a carved roll having raised bonding points configured and positioned to impart an adhesive pattern to the surface of the nonwoven web, wherein the adhesive pattern has an adhesive area percentage of about 9.6 to about 14% and a width of about 0.10 to about 0.25 mm. 2 The average of the individual bonding surface areas, and approximately 4 to 7.25 mm -1 The method according to claim 23, having an average adhesion point filling value.

25. Use of the method according to any one of claims 17 to 24 for preparing an absorbent article.

Images