MX2008004048A

MX2008004048A - Nonwoven fabric, articles including nonwoven fabrics, and methods of making nonwoven fabrics.

Info

Publication number: MX2008004048A
Application number: MX2008004048A
Authority: MX
Inventors: John A Wolhar; Michael E Kazmierczak; Carl J Wust Jr; Prashant Desai; Charlie B Allen; Gregory A Jackson
Original assignee: Fibervisions Delaware Corp
Priority date: 2005-10-03
Filing date: 2006-10-03
Publication date: 2008-10-23
Also published as: KR20080088571A; BRPI0616733A2; CA2624808A1; WO2007041620A8; CN101258029A; JP2009510278A; EP1931512A4; WO2007041620A1; CN101258029B; EP1931512A1

Abstract

Briefly described, embodiments of this disclosure include nonwoven fabrics, methods of making nonwoven fabrics, articles including nonwoven fabric, and the like.

Description

NON-WOVEN FABRIC, ITEMS THAT INCLUDE NON-TISSUE FABRICS. AND METHODS FOR PRODUCING NON-WOVEN FABRICS CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority of the provisional US patent application. with title "Bulky / Extensible Fabric", which has a serial number 60 / 723,197, filed on October 3, 2005, incorporated herein in its entirety by reference. FIELDS OF THE INVENTION The present disclosure relates to non-woven fabrics in general and to non-woven fabrics that exhibit higher swelling properties. BACKGROUND The requirements for non-woven fabrics used in applications related to hygiene, medical fabrics, wet wipes, and the like continue to increase. Moreover, qualities of utility, economy, and aesthetics must often be achieved simultaneously. The market continues to expand by polyolefin fibers and articles made thereof which have improved properties and improved softness or foaming. The production of polymeric fibers from non-woven materials usually involve the use of a mixture of at least one polymer with nominal amounts of additives, such as stabilizers, pigments, antacids and the like. The mixture is melt extruded and processed into fibers and fiber products using conventional commercial processes. Non-woven fabrics can be produced by making a weft, and then thermally bonding the fibers together. For example, basic fibers are converted into non-woven fabrics using, for example, a carding machine, and the carded fabric? It is thermally bonded. Thermal bonding can be achieved using various heating techniques, including heating with heated rolls, hot air, and heating through the use of ultrasonic welding. Fibers can also be produced and consolidated into nonwovens in various other ways. For example, fibers and nonwovens can be made by melt spinning or blown extrusion processes or a combination thereof. Also, consolidation processes may include embroidery, thermal bonding through the air, ultrasonic welding and hydroentanglement. Many non-woven fabrics, such as thermally bonded non-woven fabrics, do not show sufficient swelling or extensibility for certain purposes. Therefore, there is a need for non-woven fabrics that exhibit sufficient swelling and extensibility. COMPENDIUM Briefly described, embodiments of this disclosure include non-woven fabrics, methods for making non-woven fabrics, articles including non-woven fabrics, and the like. One embodiment of a fabric, among others, includes a non-woven fabric having at least a first fiber and a second fiber. The first fiber has a first fiber shrinkage percentage and the second fiber has a second fiber shrinkage percentage. The difference in the percentage of shrinkage of the first fiber and the percentage of shrinkage of the second fiber is at least 8 percent. One embodiment of a fabric, among others, includes a non-woven fabric having at least one first shrinkage domain and a second shrinkage domain. The first domain and the second domain define different shrinkage domains. The nonwoven fabric includes at least a first fiber and a first shrink fiber.

One embodiment of an article, among others, includes a non-woven fabric as described herein, wherein the article is selected from a wiping cloth, a diaper, a stretch fabric component, an incontinence care product, a wiping product, and female assistance, and a filter. One embodiment of a method for making a non-woven fabric, among others, includes: providing a non-woven fabric including a first fiber and a second fiber, wherein the first fiber has a percent shrinkage of first fiber and the second fiber has a percentage of shrinkage of second fiber, where the difference in the percentage of shrinkage of the first fiber and the percentage of shrinkage of second fiber is at least 8 percent; forming at least a first shrinkage domain and a second shrinkage domain, wherein the first domain and the second domain define different shrinkage domains, wherein a portion of the first fiber and a portion of the second fiber in the first domain is unite and heating the non-woven fabric to an activation temperature of the second fiber, wherein the second fiber shrinks and causes the first fiber to accumulate and increase the thickness of the non-woven fabric in the second domain. One embodiment of a method for making a non-woven fabric, among others, includes: providing a non-woven fabric including a first fiber and a second fiber, wherein the first fiber has a percent shrinkage of first fiber and the; second fiber has a second fiber shrinkage percentage, wherein the difference in the first fiber shrinkage percentage and the second fiber shrinkage percentage is at least 8 percent; and heating the non-woven fabric to an activation temperature of the second fiber, wherein the second fiber shrinks and causes the first fiber to accumulate and increase the thickness of the non-woven fabric. BRIEF DESCRIPTION OF THE DRAWINGS Many aspects of the description can be better understood with reference to the following drawings. The components in the drawings are not necessarily at scale, instead emphasis is given to clearly illustrate the principles of the present description. Moreover, in the drawings, like reference numerals designate corresponding parts in various views.

FIGS. 1A and IB illustrate graphs of a fiber shrinkage (FIG 1A) and a fiber that does not shrink (FIG IB). FIGS. 2A and 2B illustrate photomicrographs of cross-sectional views of nonwoven webs of the present disclosure. FIG. 2A illustrates a modality of a nonwoven web used to make the web; non-woven sponge that has not been activated by the thermal foaming stage. FIG. 2B illustrates the non-woven web that has been activated to produce the spongy non-woven web. FIG. 3 illustrates Table 1, which describes a number of modalities of non-woven fabrics of the present disclosure. DETAILED DESCRIPTION Modalities of the present description will employ, unless otherwise indicated, textile, chemical, and the like techniques, which are within the skill of the art. Such techniques are fully explained in the literature. The following examples are presented to provide those of ordinary skill in the art with a complete description of how to carry out the methods and use the compositions and compounds described and claimed herein. Efforts have been made to ensure accuracy with respect to numbers (ie, quantities, temperature, etc.), but some errors and deviations must be taken into account. Unless stated otherwise, parts are parts by weight, temperature is in ° C, and the pressure is or is almost atmospheric. Temperature and standard pressure are defined as 25 ° C and 1 atmosphere. Before the embodiments of the present disclosure are described in detail, it should be understood that, unless otherwise indicated, the present disclosure is not limited to particular materials, reagents, reaction materials, processing processes, or their like. , as they may vary. It should also be understood that the terminology used here is for purposes of describing particular modalities only, and is not intended to limit them. It is also possible in the present description which steps can be executed in different sequence when this is logically possible. It should be noted that, as used in the specification and appended claims, the singular forms "a" and "the, the, the," include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a support" includes a plurality of supports. In this specification and in the claims below, reference will be made to a number of terms that should be defined as having the following meanings unless a contrary intention is apparent. It should be noted that proportions, concentrations, quantities and other numerical information can be expressed here in a range format. It should be understood that said rank format is used for convenience and brevity, and therefore, should be interpreted in a flexible manner to include. not only the numerical values explicitly shown as the limits of the range, but also to include all the individual numerical values or subranges comprised within the range as if each numerical value and subrange will be explicitly displayed. To illustrate, a concentration range of "about 0.1% to 5%" should be interpreted to include only the explicitly recited concentration of about 0.1% by weight to about 5% by weight, but also to include individual concentrations (i.e. %, 2%, 3%, and 4%) and subranges (ie, 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the indicated range. Definitions When describing and claiming the object of the description? (In describing and claiming the verb subject raatter), the following terminology will be used in accordance with the definitions presented below. The term "non-woven" fabric, sheet, or weft as used herein means a textile structure of individual fibers, filaments, or yarns that are directionally or randomly oriented and interact with one another by friction, and / or cohesion, and / or. adhesion, as opposed to a regular pattern of mechanically interconnected fibers (ie, it is not a woven fabric). Examples of non-woven fabrics and wefts include, but are not limited to, carded wefts, wefts formed by air jet, and wefts formed with water. Bonding methods include thermal bonding, chemical or solvent bonding, resin bonding, mechanical puncture, puncture. hydraulic, - stitch link, combinations thereof, and the like. An illustrative non-limiting embodiment of the present disclosure includes thermally bonded non-woven webs.

The terms "linked" or "link" are used herein to describe areas of a non-woven fabric having an inter-fiber or greater matted bond that occurs in non-woven fabrics. The term "fluffing" or "thick and fluffy" is used as an indication of the specific swelling volume of the nonwoven for a given area density. The terms "fluffing" or "thick and fluffy" are generally used interchangeably. In this way, the term "fluffing" is used to describe "fluffing" and "thick and fluffy." Specific volume of swelling can be obtained by dividing the volume of swelling of a non-woven sample and by its mass. A spongy nonwoven is relatively less dense than compressed. The storage density is mass per unit area and is usually reported as grams per square meter (gsm). Area density is often referred to as "base weight" and the terms are equivalent. The terms "shrinkage", "" shrinkage "," shrinkage "as they are used with reference to fibers refer to the reduction in fiber length measured by thermomechanical analysis (TMA = Thermomechanical Analysis). A typical instrument for measuring shrinkage is the Model Q400, developed by TA Instruments. A discussion of shrinkage can be found in "Thermal Characterization of Polymeric Materials," Academic Press (1981) p. 736-743, which is incorporated herein by reference. FIGS. 1A and IB illustrate graphs of a fiber that shrinks and a fiber that does not shrink. The term "extensibility" as used in reference to non-woven fabrics refers to the fabric's ability to show great elongation during the application of tension. The term "elasticity" refers to the ability of an extensible nonwoven to essentially return to its pre-tension state by releasing tension. The term "activate" refers to a process used to increase the swelling subsequent to the formation of the non-woven fabric. General Discussion Briefly described, modalities of this description. they include non-woven fabrics, methods ... for making non-woven fabrics, articles that include non-woven fabrics, and the like. The non-woven fabric of the present disclosure has improved effects (i.e., increased swelling, adjustable texture feel, improved entrapment of foreign particles, increased area density, and the like) compared to other non-woven fabrics. In addition, the non-woven fabrics are highly extensible in relation to other non-woven fabrics. The degree of extensibility is dependent on activation temperature, fabric preparation, bond pattern, and the like. Under some conditions, a degree of elasticity may also be present which in turn depends on the activation temperature, fabric work, pattern, and the like. Non-woven fabrics may be included in articles such as, but not limited to, wipes, diapers, stretch fabrics, incontinence care products, feminine care products, filters, felts, and the like. The non-woven fabrics can be used in articles in the positioning zones, in the acquisition / distribution layers, sections of,. Stretching, top sheet, back sheet, and the like. The non-woven fabrics can be made to have a predetermined swelling, a certain softness / hardness, area density, and the like, when selecting components of the non-woven fabric (i.e., fibers), parameters for treating the non-woven fabric, link, and similar. In other words, the non-woven fabric can be designed for many applications, such as, but not limited to, cleaning surfaces (i.e., soft surface or hard surface); acquire, distribute or transport liquids; add comfort, filter liquids, gases or dust; acoustic attenuation, and / or their combinations. In general, the non-woven fabric includes one or more non-woven layer (s), wherein the non-woven layer (s) includes at least a first fiber and a second fiber. The first fiber and the second fiber have different levels or shrinkage ranges under certain conditions (ie activation temperature and shrinkage time of the fibers, and degree of limitations against dimensional change). During activation, the second fiber shrinks, and while the second fiber shrinks in size it pulls some first fibers with. It is used to produce one or more areas of raised sponge.The non-woven fabric can increase in foaming from about 20 to 500%, about 30 to 450%, and about 50 to 350% relative to the foaming of the non-woven non-woven fabric. The non-woven fabric can increase in thickness by about 30 to 650% about 45 to 550%, and about 60 to 500% relative to the thickness of the non-activated non-woven fabric.The activation conditions (i.e., temperature and time) or degree of limitations against dimensional change) applied to the non-woven fabric depend, at least in part, on the composition of the fiber, the amount of shrinkage desired, the texture to the touch (ie, soft to hard) of the desired non-woven fabric, the amount of desired swelling, the level of extensibility and elasticity desired, and the like.The activation of the fibers in non-woven fabric is typically performed while the fibers are in a non-woven fabric. It is relaxed (that is, porca or no tension in the direction of the machine or cross direction in relation to the force generated by the shrinking fibers). In another embodiment, the shrinkage can be controlled. , in the direction of the 7/0 machine the cross direction using controlled dimensional change processes such as, but not limited to, frame dryer processes, sanforization processes, curling processes, allied processes, and your combinations The activation conditions, the types of fiber, the number of non-woven layers in the non-woven fabric, and the like, are chosen to produce desired effects (i.e., swelling, texture to the touch, and combinations thereof). The shrinkage can also be controlled in the machine direction and / or the transverse direction by controlling the radius of the number of fibers oriented in the machine direction to the number of fibers oriented in the cross direction. In general, the activation temperature (ie, from the furnace or other heat source) of the second fiber is below the melting point of the polymer. Therefore, the activation conditions depend, at least in part, on the type of polymeric fibers used as the second fiber. For example, the activation temperature when the second fiber is polypropylene is from about 125 ° C to 150 ° C for a time from about 10 seconds to 1 minute. The activation temperature can >; ^ achieved by processes such as, but not limited to, hot gas, infrared heat sources, furnaces, and the like. A person skilled in the art can modify one or both of the temperature and time conditions to achieve the desired results. In another embodiment, the non-woven fabric includes a pattern of differentiated shrinkage domains. Differentiated shrinkage domains are defined by a binding pattern (described below) of the first domains and the second domains. The first shrinkage domain is defined as the area of the non-woven fabric that is bonded (i.e., a portion of the first fibers and the second fibers are bonded to one another), while the second shrinkage domain is defined as the area of nonwoven fabric that is not linked. The shrinkage of the first domain under the activation conditions is very small in relation to the shrinkage of the second domain under activation conditions. The first fibers and the second fibers are included in both of the first domains and the second domains and portions of fibers may be present in both domains. As mentioned "above, the first fiber and the second fiber have different shrinkage ranges under certain conditions" (ie activation temperature and fiber shrinkage time). Exposing the non-woven fabric to activation conditions causes the second fibers shrink in length.While the second fibers shrink, the second fibers pull the first fibers together with them.The shrinkage of the second fibers causes the first fibers to gather in regions of the second domain, which may increase the Non-woven fabric swelling The increase in swelling is enhanced when the non-woven fabric is bonded in pattern so that the bonded regions prevent unraveling of the first fibers and the second fibers In an exemplary embodiment, a non-woven fabric includes a single non-woven layer that includes a mixture of the first and second fibers.The non-woven fabric has a pattern of shrinkage domains differentiated caused by linking the first domains of the non-woven web (first link domain), and leaving other portions > unlinked (second link domain). In one embodiment, the first fiber is a fiber that does not shrink (defined below) and the second fiber is a shrink fiber. "The fiber that does not shrink, and the shrinkage fiber has different shrinkage ranges under certain activation conditions.The non-woven fabric is exposed to activation conditions that cause the shrinkage fiber to shrink. shrinks, while fiber that does not shrink does not shrink substantially (as described below) .The shrinkage fiber causes non-shrinkage fibers to gather in the second domains and increase the swelling of the non-woven fabric In another exemplary embodiment, a non-woven fabric includes: a first non-woven layer including a first fiber, a second non-woven layer including a second fiber, and a non-woven third layer including the first fiber. it has a pattern of differentiated shrinkage domains caused by linking the first domains of the non-woven fabric (that is, linking the first, the second, and the non-woven third layers), and leaving other portions unbound ar (second link domain). In one embodiment, the first fiber is a fiber that does not shrink (defined below) and the second fiber is a shrinkage fiber. Fiber that does not shrink and shrink fiber have different degrees of shrinkage "lowered certain activation conditions.The non-woven fabric is exposed to activation conditions that cause the shrinkage fiber to shrink, while fiber that shrinkage does not shrink substantially (as described below) The shrinkage fiber in the second non-woven layer causes fibers that do not shrink in the first and third non-woven layers to meet in the second domains and increase the swelling of the non-woven fabric Non Woven Fabric As mentioned above, the non-woven fabric includes, but is not limited to, at least a first fiber and a second fiber. In one embodiment the nonwoven fabric includes a first fiber, a second fiber, and a third fiber. Other embodiments may include four or more fibers (i.e., a first fiber, a second fiber, and an "nth" fiber). Details of the fibers are described here. The non-woven fabric may include one or more non-woven layers (ie, a first non-woven layer, a second non-woven layer, ... and an "nth" non-woven layer). Modes of the present disclosure may include non-woven fabrics having 1, 2, 3, 4, 5, "6- * · 7" .. &;, 9, 10, or more, non-woven layers. Each non-woven layer may include, but is not limited to, a first fiber and / or a second fiber as well as additional fibers. In one embodiment, the non-woven layers alternate between a non-woven layer including a first fiber and a non-woven layer including a second fiber. In one embodiment, the non-woven layers alternate between a non-woven layer that includes a non-shrinkable fiber and a non-woven layer that includes a shrinkable fiber. Representative embodiments of non-woven fabrics are described herein, while other embodiments having at least the first fiber and the second fiber having different levels or shrinkage ratios are also included within the scope of the present disclosure. In one embodiment, the non-woven fabric includes a non-woven layer. The non-woven layer includes at least the first fiber and the second fiber. In another embodiment, the non-woven layer includes the first fiber, the second fiber, and one or more additional fibers. In one embodiment, the nonwoven fabric includes a first nonwoven layer and a second nonwoven layer. The first non-woven layer is placed in the second non-woven layer. In the mode, the first non-woven layer is made from the first fiber and the second non-woven layer is made from the second fiber In another embodiment, the first non-woven layer is made from the first fiber and the second layer is made from the first fiber. second fiber and the second nonwoven layer is made from the first fiber, the second fiber, a third fiber, or any combination thereof In one embodiment, the nonwoven fabric includes a first nonwoven layer, a second nonwoven layer and a third nonwoven layer In one embodiment, the first nonwoven layer and the third nonwoven layer are made from the first fiber, while the second nonwoven layer is made from the second fiber. The non-woven layer is made from a first fiber, the second non-woven layer is made from a second fiber, and the third non-woven layer is made from a third fiber In another embodiment, any of the non-woven layers described in the above embodiments can include combinations of first fiber, second fiber, third fiber, and / or one or more other fibers. In each of the modalities of the non-woven fabrics, the types of fibers and the combination of fibers (for example, in the same layer or in different layers) can be selected according to the particular characteristics (ie, fluffing). of the non-woven fabric, texture of one or more surfaces of the non-woven fabric, and the like) desired for a particular non-woven fabric.

It should be noted that the conditions under which the non-woven fabric is bonded and activated as well as the pattern of differentiated shrinkage domains can be used to tailor the characteristics of the non-woven fabric. Non-woven fabrics can be made using one or more processes. Non-woven fabrics can be formed using processes such as, but not limited to, carded thermal bonding, interwoven carded yarn, carded bonding through the air, wet laying, basting with carded punch, bonded yarn, air-laying, extruding with blowing , and combinations thereof, each of which have the meaning typically attributed to them in the art. In one embodiment, non-woven fabrics are made using thermal carded bonding processes. Further details regarding modalities of the non-woven fabric are described in the examples. As mentioned above, non-woven fabrics have a pattern of differentiated co-pending domains. The patterns of differentiated shrinkage domains can be processed using known standards (i.e., that can be provided by any manufacturer, such as Andritz K Sters GmbH &Co. KG (Germany), and the like) or by using other patterns as well. The patterns can be made using processes such as calender bonding with pattern rollers, hydroentangling pattern forming propellant, basting with pattern punch, and the like, and combinations thereof. After the fibers of the non-woven fabric have been subjected to activation conditions to form the swelling, the non-woven fabric can be subsequently treated. Subsequent treatments include, but are not limited to, corona, plasma, loosening of dirt, pyro-retardant, softener, and the like, and their combinations. Fibers The first fiber may include, but is not limited to, natural fibers or naturally derived fibers (hereinafter referred to as "natural fibers"), thermoplastic polymer fibers, and high performance thermosetting polymer fibers. The second fiber may include, but is not limited to, polymer fibers (ie, thermoplastic polymer fibers). Additional fibers (ie, the third fiber and so on) may include, but are not limited to, natural fibers, polymeric fibers, and high performance thermosetting polymer fibers. The first fiber and the second fiber can include, but are not limited to, fibers of polymer blends, bi-component fibers (ie, a fiber comprising two different polymers of different constitution / chemical properties), and bi-constituent fibers ( that is, fibers composed of two or more different fibers combined before the extrusion process). The first fiber and the second fiber can be made by the same process or by a different process. Natural fibers may include, but are not limited to, plant fibers, plant fibers, and animal / insect fibers. Natural fibers are derived from fibers of animal skins and silkworm cocoons, and fibers from seeds of plants, leaves, stems, and the like. Exemplary natural fibers include, but are not limited to, wool, cotton, silk, linen, ramie, hemp, and jute. In one embodiment, natural fiber includes, but is not limited to, rayon, Lyocell, polylactic acid, soy protein, and combinations thereof. High performance thermostable polymers may include, but are not limited to, carbon fibers, glass fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers, polyararaide fibers, combinations thereof, and the like. Polymeric fibers and thermoplastic polymer fibers can be made from copolymers, terpolymers, and larger polymers. It should be noted that the term "copolymer" includes two or more monomers in the same polymer chain. The polymeric fibers and thermoplastic polymer fibers may be mono-component or multi-component. The polymer fibers and thermoplastic polymer fibers can be polymer blends. The polymer fibers and thermoplastic polymer fibers can include thermoplastic polymers such as, but not limited to, polymer blends or copolymers of each of the following: polyolefins, polyesters, polypropylene, polyethylene, polybutene, polymethylpentene, ethylene-propylene, polyamides, polyurethanes, polyvinyl acetates, ethylene vinyl acetates, polyether esters, polyether urethane, * - .- polyvinyl acetates, and, -.- /, their ... combinations. In one embodiment, the polymeric fibers and thermoplastic polymer fibers can be made from materials such as, but not limited to, polymer blends or copolymers of each of the following: polyolefins, polyesters, polyamides, polyvinyl acetates, polyacrylonitriles, polyvinyl alcohol and ethylene acid Acrylic, and its combinations. In one embodiment, the polymeric fibers and thermoplastic polymer fibers can include polymeric spinning materials such as polyolefins and blends comprising polyolefins (for example, see U.S. Patents Nos. 5,733,646, 5,888,438, 5,431,994, 5,318,735, ,281,378, 5,882,562 and 5,985,193, the descriptions of which are hereby incorporated by reference in their entirety). In one modality, the. Polymer is a polypropylene or a mixture that includes a polypropylene. The polypropylene can include polypropylenes that are spun. The polypropylene can be atactic, heterotactic, syndiotactic, isotactic and stereo block polypropylene including partial and complete isotactic polypropylenes, or at least -isotica. icos * substantially complete. ..... The terms polymers (ie, polyolefins, polypropylene, polyethylene, and the like) include homopolymers and heteropolymers (ie, copolymers and terpolymers), and mixtures thereof (including mixtures and alloys produced by mixing separate batches or forming a mix in if you). For example, the polymer may include copolymers of olefins, such as propylene, and these copolymers may contain various components. As used herein, polypropylene is used in its ordinary commercial meaning where polypropylene is a substantially linear molecule. In addition, as used herein, a polypropylene composition includes a material that contains a broad molecular weight distribution of linear polypropylene to enable the obtaining of fibers and filaments having superior spinning and thermal bonding characteristics. Conventional polymer fibers include discontinuous or short polypropylene fibers. These fibers may also include bicomponent fibers containing various combinations of polypropylene or a combination of other polymeric materials such as polyethylene. A polymeric fiber of particular interest conventionally used to make nonwoven webs or fabrics is a high bonding thermal bonding fiber described in US Pat. Number 5,281,378, incorporated herein by reference is its entirety. In one embodiment, the polypropylene can have an average molecular weight of from about 3xl05 to about 5xl05, a melt interlacing flow rate, MFR (MFR = Melt Flow Rate) (determined according to ASTM (ASTM = American Society for Testing and Materials) D-1238-86 (condition L; 230 / 2.16), which is hereby incorporated by reference in its entirety) from about 7 to about 50 dg / min, and / or a spinning temperature within the range of about 220 at 315 ° C, approximately 240 to 300 ° C, and approximately 255-285 ° C. In one embodiment, the polypropylene can be linear or branched, such as is described in US Pat. Number 4,626,467, which is incorporated herein by reference in its entirety, and is preferably linear. In addition, the polypropylene to be made into fibers can include polypropylene-recomo compositions taught in US Pat. Nos. 5,629,080, 5,733,646 and 5,888,438 and European Patent Application Number 0 552 013, which are incorporated herein by reference. in their totalities. Moreover, polymer blends such as those described in US Pat. Number 5,882,562, and European Patent Application Number 0 719 879, which are incorporated herein by reference in their totals, may also be used. The first and second fibers can have an equal or different size and / or cross section. The first fiber and the second fiber have a denier of approximately 0.1 to 50 denier per filament ?. The first fiber and the second fiber can be continuous or discontinuous, with a length of about 1 mm to 250 mm. The melt flow rate, (MFR = melt flow rate), depends on the type of polymer with which the fiber is made, and, thus, the MFR can vary depending on which fibers are selected for each particular application. In one embodiment, the first polyolefin fiber and the second polyolefin fiber may have a melt flow rate or rate (determined according to ASTM D-1238-86 (condition L; 230 / 2.16), which is incorporated herein by reference in its totality of approximately 10 to 400 dg / ml: n, but the MFR depends on the chemical composition of the fibers. First fiber has a percentage of shrinkage of first fiber (measured using TMA) and the second fiber has a second fiber shrinkage percentage, where the difference in the percentage of shrinkage of first fiber and the percentage of second fiber shrinkage is at least 8 percent; it is at least 9 percent; is at least 10 percent, is at least 12 percent, or is at least 15 percent. It should be noted that in one embodiment the first fiber can not shrink or increase in length. In one embodiment, the first fiber has a first fiber shrinkage ratio of less than about 10 percent, less than about 8 percent, less than about 6 percent, less than about 3 percent, or less than about 1 percent , where each is measured in the same conditions (ie, a temperature close to the activation temperature of the fiber of interest), and can be referred to as the "fiber that does not shrink". Fiber that does not shrink can include, but? It is not limited to, polypropylene, polyester, and combinations thereof. In a mode wherein the non-shrinking fiber is made of polypropylene, the fiber shrinkage is less than about 10 percent at about 140 ° C. It should be noted that in a modality fiber that does not shrink can not shrink and increase length. The second fiber has a fiber shrinkage greater than about 9 percent, greater than about 10 percent, greater than about 11 percent, greater than about 12 percent, greater than about 13 percent, and can be referred to as " shrink fiber ". The shrinkage fiber may include, but is not limited to, polypropylene, polyester, polyethylene, and bicomponent fibers made therefrom. In an embodiment wherein the shrink fiber is made of polypropylene, the fiber shrinkage is about 9 to 40 percent at 140 ° C. The production of polymer fibers from nonwoven materials may include the use of a blend of At least one polymer with nominal amounts of additives, such as, but not limited to, antioxidants, stabilizers, pigments, antacids, process assistants and the like. In this manner, the polymer or polymer mixture may include various additives, such as, but not limited to, melt stabilizers, antioxidants, pigments, antacids, antistatic solvents, emulsifiers, preservatives, and process assistants or auxiliaries. The types, identities, and amounts of additives can be determined by those with ordinary skill in the specialty in consideration of product requirements. Various finishes can be applied to the fibers to maintain or make them hydrophilic or hydrophobic. Finishing compositions including hydrophilic finishes or hydrophobic finishes can be selected by those skilled in the art according to the characteristics of the apparatus and the needs of the product being made. Also, one or more components can be included in the polymer blend to modify the surface properties of the fiber, thereby providing the fiber with repeated wettability, or to avoid or reduce the buildup of static electricity - Hydrophobic topcoat compositions preferably They include antistatic agents. Hydrophilic finishes can also include those agents.

Further details regarding modalities of the non-woven fabric are described in the examples. Now, having described the embodiments of the present disclosure, in general, the Examples describe some additional embodiments of the present disclosure. While the embodiments of the present disclosure are described in connection with the Examples and the corresponding text and figures, it is not intended to limit the embodiments of the present disclosure to these descriptions. On the contrary, it is intended to cover all alternatives, modifications, and equivalents included within the spirit and scope of the embodiments of the present disclosure. Table 1, as shown in Figure 3, illustrates some exemplary embodiments of non-woven fabrics A-G with combinations of fibers NS1, NS2, NS3, NS4, NS5, SI, and S2. The examples provide a number of modalities by emptying in the weight of the fabric, workmanship, fiber composition, fiber type, number of non-woven layers, method of making the fabric, and the like. Figures 2A and 2B illustrate microphotographs of cross-sectional views of nonwoven webs of A in Table 1. Figure 2A illustrates one embodiment of a non-woven fabric used to make the non-woven spongy fabric that has not been activated by the stage of thermal foaming. Figure 2B illustrates the nonwoven web that has been activated to produce the spongy nonwoven web. It should be emphasized that the above described embodiments of the present description are merely possible examples of implementations, and are presented solely for a clear understanding of the principles of the description. Many variations and modifications can be made to the above-described embodiments of the description without substantially departing from the spirit and principles of the description. All such modifications and variations are intended to be included within the scope of this description and protected by the following claims.

Claims

CLAIMS 1. A fabric characterized in that it comprises: a non-woven fabric having at least a first fiber and a second fiber, wherein the first fiber has a percentage of shrinkage of the first fiber and the second fiber has a percentage of second fiber shrinkage , wherein the difference in the first fiber shrinkage percentage and the second fiber shrinkage percentage is at least about 8 percent. The fabric according to claim 1, characterized in that the nonwoven fabric includes at least a first shrinkage domain and a second shrinkage domain, wherein the first domain and the second domain define differentiated shrinkage domains. 3. The fabric according to claim 1, characterized in that the difference in the percentage of shrinkage of the first fiber and the percentage of shrinkage of the second fiber is at least 10 percent. 4. The fabric according to claim 1, characterized in that the first fiber is a fiber that does not shrink, wherein the fiber that does not shrink has a first fiber shrinkage ratio of less than about 5 percent. 5. The fabric according to claim 1, characterized in that the first fiber is a fiber that does not shrink, wherein the fiber that does not shrink has a first fiber shrinkage ratio of less than about 3 percent. The fabric according to claim 1, characterized in that the first fiber is a polymeric thermoplastic fiber made from a polymer selected from: polymer blends or copolymers of each of the following: polyolefins, polyesters, polypropylene, polyethylene, polybutene, polymethylpentene, ethylene-propylene, polyamides, polyurethanes, polyvinyl acetates, ethylene vinyl acetates, polyether esters, polyether urethane, polyvinyl acetates, and combinations thereof; wherein the second fiber is a thermoplastic fiber selected from: polymer blends, or copolymers, of each of the following: polyolefira, polyesters, polypropylene, polyethylene, polybutene, polymethylpentene, ethylene-propylene, polyamides, polyurethanes, polyvinyl acetates, ethylene vinyl acetates, polyether esters, polyether urethane, polyvinyl acetates, and combinations thereof. The fabric according to claim 1, characterized in that the first fiber is a natural fiber made of a material selected from: wool, cotton, silk, linen, ramie, hemp, jute, and combinations thereof; wherein the second fiber is a polymeric fiber selected from: polymer blends or copolymers of each of the following: polyolefins, polyesters, polypropylene, polyethylene, polybutene, polymethylpentene, ethylene-propylene, polyamides, polyurethanes, polyvinyl acetates, ethylene. vinyl acetates, polyetheresters, polyetherurethane, polyvinyl acetates, and combinations thereof. The fabric according to claim 1, characterized in that the first fiber is a fiber derived from natural material selected from: rayon, Lyocell, polylactic acid, soy protein, and combinations thereof; wherein the second fiber is a polymer fiber selected from: blends of polymers and copolymers desired one of the following: polyolefins, polyesters, polypropylene, polyethylene, polybutene, polymethylpentene, ethylene-propylene, polyamides, polyurethanes, polyvinyl acetates, ethylene vinyl acetates, polyether esters, polyetherurethane, polyvinyl acetates, and combinations thereof. The fabric according to claim 1, characterized in that the first fiber is a fiber selected from: carbon fibers, glass fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers, polyaramide fibers, combinations thereof; wherein the second fiber is a polymer fiber selected from: polymer blends and copolymers of each of the following: polyolefins, polyesters, polypropylene, polyethylene, polybutene, polymethylpentene, ethylene-propylene, polyamides, polyurethanes, polyvinyl acetates, ethylene vinyl acetates, polyether esters, polyetherurethane, polyvinyl acetates, and combinations thereof. 10. The fabric according to claim 1, characterized in that the non-woven fabric includes at least a first non-woven layer, wherein the first ?? fiber and the second fiber are », include in the -first non-woven layer. 11. The fabric according to claim 1, characterized in that the non-woven fabric includes a third fiber having a third percentage of fiber shrinkage, wherein the difference in the percentage of shrinkage of the third fiber and the percentage of shrinkage. The second fiber is at least 8 percent, wherein the non-woven fabric includes at least a first non-woven layer, wherein the first fiber, the second fiber, and the third fiber are included in the first non-woven layer. 12. The fabric according to claim 1, characterized in that the non-woven fabric includes at least two non-woven layers, wherein a first non-woven layer is placed on a second non-woven layer, and wherein the first fiber is placed on a non-woven layer. in the first non-woven layer and the second fiber is in the second non-woven layer. The fabric according to claim 1, characterized in that the non-woven fabric includes at least three non-woven layers, wherein a first non-woven layer is placed on a second non-woven layer, wherein a third non-woven layer is placed on the second non-woven layer on the side; opposite of the first non-woven layer, wherein the first fiber is in the first non-woven layer and the third non-woven layer, and wherein the second fiber is in the second non-woven layer. 14. The fabric according to claim 1, characterized in that the first fiber and the second fiber each are selected from: polymer blend fibers, bi-component fibers, bi-constituent fibers, and combinations thereof. 15. An article, characterized in that it comprises: a non-woven fabric having at least one first fiber and a second fiber, wherein the first fiber has a first fiber shrinkage percentage and the second fiber has a shrinkage percentage. of second fiber, wherein the difference in the first fiber shrinkage percentage and the second fiber shrinkage percentage is at least about 8 percent, and wherein the article is selected from a cleaning wipe, a diaper, an elastic textile component, an incontinence care product, a female care product, felts, and a filter. 16. A fabric, characterized in that it comprises: a non-woven fabric having at least a first shrinkage domain and a second shrinkage domain, wherein the first domain and the second domain define different shrinkage domains, and wherein The non-woven fabric includes at least a first fiber and a first shrink fiber. 17. The fabric according to claim 16, characterized in that the first fiber is a first polypropylene fiber and wherein the first shrink fiber is a second polypropylene fiber, wherein the first polypropylene fiber and the second fiber of polypropylene have a difference in percent shrinkage of at least 8 percent. 18. A method for forming a non-woven fabric, characterized in that it comprises: providing a non-woven fabric including a first fiber and a second fiber, wherein the first fiber has a first fiber shrinkage percentage and the second fiber has a second fiber. second fiber shrinkage percentage, where the difference in the first shrinkage percentage and the second shrinkage percentage is at least 8 percent; form at least a first domain of shrinkage and a second . enforcement domain, where the < The first domain and the second domain define different shrinkage domains, where a portion of the first fiber and a portion of the second fiber in the first domain are joined; and heating the non-woven fabric to an activation temperature of the second fiber, wherein the second fiber shrinks and causes the first fiber to accumulate and increase the thickness of the non-woven fabric in the second domain. A method for forming a non-woven fabric, characterized in that it comprises: providing a non-woven fabric including at least a first fiber and a second fiber, wherein the first fiber has a percentage of shrinkage of first fiber and the second fiber has a second fiber shrinkage percentage, wherein the difference in the first fiber shrinkage percentage and the second fiber shrinkage percentage is at least about 8 percent, and heat the nonwoven fabric to an activation temperature of the second fiber. second fiber, where the second fiber shrinks and causes the first fiber to accumulate and increase the thickness of the non-woven fabric.