Patent Publication Number: US-2019194827-A1

Title: Hybrid yarns formed with fibers having rounded tips and method of making the same

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to yarns. More particular, the present invention relates to the use of combinations of different fiber shapes to create yarns. Still more particularly, the present invention relates to hybrid yarns and fabrics made from such yarns. 
     2. Description of the Prior Art 
     Fabrics are typically comprised of yarns made of a plurality of fibers that are combined together. The yarns may be made of natural fibers, such as cotton, and man-made fibers, such as synthetic polymers formed into fibers. These fabrics are typically produced with one or more yarns that are joined together by weaving, stitching or other forms of joining. The yarns selected to make fabrics are chosen based on the desired functionality of the fabric and the look and feel of the fabric. Synthetic yarns are generally made of any of a variety of polymers and are made with fibers of different thicknesses and shapes. The yarns are formed of a plurality of fibers combined together into a bundle. 
     Most synthetic manufactured fibers are created by “extrusion”—forcing a thick, viscous liquid through the tiny holes of a device called a spinneret to form continuous filaments of semi-solid polymer. In their initial state, the fiber-forming polymers are solids and therefore must be first converted into a fluid state for extrusion. This is usually achieved by melting of thermoplastic polymers, an example of which is polyester, but is not limited thereto. The spinnerets used in the production of most manufactured fibers are similar, in principle, to a bathroom showerhead. A spinneret may have from one to several hundred holes. The tiny openings are very sensitive to impurities and corrosion. The liquid feeding them must be carefully filtered and, in some cases, the spinneret may be made from very expensive, corrosion-resistant metals or other suitable materials. Maintenance is also critical, and spinnerets must be removed and cleaned on a regular basis to prevent clogging. 
     As the continuous filaments emerge from the holes in the spinneret, the liquid polymer is converted first to a rubbery state and then solidified. This process of extrusion and solidification of endless filaments is called spinning, and for polymer filaments there are four types of spinning: wet, dry, melt, and gel spinning. In melt spinning, the filament-forming substance is melted for extrusion through the spinneret and then directly solidified by cooling. Nylon, polyester and other synthetic polymers are produced in this manner. While extruded filaments are solidifying, or in some cases even after they have hardened, the filaments may be drawn to impart strength. Drawing pulls the molecular chains together and orients them along the filament axis, creating a considerably stronger yarn. 
     When polymer filaments emerge from the spinneret, they are soft and easy to elongate by stretching. The extent of elongation is dependent on the particular polymer. The stretching forces polymer molecules to align in a parallel formation. This increases the strength, tenacity, and resilience of the filament. Filament draw may be varied to change greatly the diameter and length, depending on the characteristics desired of the finished material. Also, as the filaments are drawn, they may be textured or twisted to create softer or duller fabrics. After the filaments are drawn, they are twisted together to produce the yarn. Synthetic yarns are identified by the polymer used, weight per unit length, referred to as its Denier, and the number of fiber filaments used to make it. For example, a 75×72 polyester yarn has a Denier of 75 made with 72 filaments twisted together. 
     A “fiber” is a unit of matter, either natural or manmade that forms the basic element of fabrics and other textile structures. A fiber is generally characterized by having a length at least 100 times its diameter or width. In relation to the present invention, it will be used to identify units of natural or man-made materials having a length at least 100 times its diameter, width or longest cross-sectional dimension that can be spun into a yarn or made into a fabric by various methods including weaving, knitting, braiding, felting, and twisting. A “filament on the other hand, is a fiber of unspecified length, although a filament yarn ordinarily has filaments that are as long as the length of the yarn, which may be selectable by cutting the filaments to a desired length. Manufactured fibers are extruded into filaments that are converted into filament yarn, staple or tow. A “filament yarn” is composed of continuous filaments that may or may not be twisted together. A “spun yarn” is a yarn of staple fibers usually held together by twist or a melt-spun fiber before it is drawn. A “textured yarn” is a yarn that develops stretch and bulk on subsequent processing. A “staple fiber” is a natural fiber or a filament of synthetic material that has been cut to a length. The length of a natural staple fiber varies from less than an inch (for example with cotton) to more than a foot (hard fibers) dependent on the materials. Manufactured staple fibers are cut to pre-determined length so that they may be processed. The term “staple fiber” is utilized in the textile industry to distinguish natural or cut-length manufactured fibers from filament. A staple fiber is typically considered to be substantially shorter than a filament These definitions are applicable in the description of the present invention. 
     Many fabrics are made with combinations of materials because it is difficult to provide all desired fabric characteristics with a single yarn formed with a single natural or synthetic material. For example, a fabric may be made of a polyester yarn comprising two different fiber materials, such as, for example, a combination of a polyamide, such as Nylon, and cotton, or polyamide and a polyester. The polyamides have certain desired characteristics, such as good strength, resiliency and ease of maintenance. The polyesters have certain desired characteristics, such as wrinkle resistance, high durability and good color retention. Fabrics may also be made with combinations of different yarns made with the same polymer material, such as Nylon or polyester, but with each of these different yarns having a plurality of fibers with the same shapes. For example, a first polyester yarn may be formed of fibers that are close to round in shape and a second polyester yarn may be formed of “technically shaped” fibers, such as trilobal or X-shape, for example. A yarn made with relatively round fibers is less expensive than a yarn made of technically shaped fibers, but the trilobal yarn, for example, has other qualities that are better, such as better moisture wicking. Fabrics are made of combinations of yarns to optimize desired physical characteristics and minimize the cost of manufacture. The ability to make lighter weight fabrics of selectable functionality has not been feasible with existing yarn constructions and fabric making methods because it has been necessary to combine together individual yarns to accomplish the desired functionality. That resulted in fabrics heavier than desired by consumers. The balance of functionality and weight has always been a difficulty. The hybrid yarn of the present invention resolves that difficulty. 
     A simplified representation of a process for making a synthetic yarn of a single polymer but with three different fiber shapes is shown in  FIG. 1 . In this example, the yarn is a 150/192 yarn. That is, it is a 150 Denier and is made with 192 fibers in the bundle. One third of its fibers are “Y” in shape, one third of its fibers are hollow and the remaining third of its fibers are in “X” shape. In a first step of the process, polyester polymer from source  12  is melted and passed through spinneret  14  to generate first polyester filaments  16 . Spinneret  14  includes a plurality of Y-shape ports, in this example, 64 such ports, through which the liquefied polyester passes. In a second step, which may occur at the same time or a different time than that of the first step, polymer from source  12  is melted and passed through spinneret  24  to generate second polyester filaments  26 . Spinneret  24  includes a plurality of ring-shaped ports, in this example, 64 such ports, through which the liquefied polyester passes. In a third step, polymer from source  12  is melted and passed through spinneret  34  to generate third polyester filaments  36 . Spinneret  34  includes a plurality of X-shape ports, in this example, 64 such ports, through which the liquefied polyester passes. The first polyester filaments  16  are cooled and twisted together on twister  18  to make first polyester bundle  19 , the second polyester filaments  26  are cooled and twisted together on twister  28  to make second polyester bundle  29  and the third polyester filaments  36  are cooled and twisted together on twister  38  to make third polyester bundle  39 . Each of the sets of filaments made may be further modified to give them texture or crimping, for example. They may also be cut to change them from filaments to staple fibers. The sets of twisted filaments are then twisted together on twister  40  to produce yarn  42  that is a bundle of bundles  19  and  29 .  FIG. 2  shows that bundles  19 ,  29  and  39  are adjacent to one another in the yarn  42 . 
     It is understood that different yarns formed with synthetic fibers of different polymeric materials and/or different yarns formed with synthetic fibers made of the same polymeric material, but different fiber shapes can be used to make fabrics of interest. However, even that optimization has its limits. Specifically, because yarns are made of bundles of fibers, it is very difficult to take full advantage of the characteristics of each individual fiber, particularly those fibers that are not at the exterior of the bundle. As a result, a yarn made using relatively expensive polymer and with fibers that are shaped in a particular way to impart desired features can provide only a portion of those desired characteristics. In the example represented in  FIG. 1  and as shown in  FIG. 2 , which is a representation of a portion of the yarn  32 , fibers in the bundles of the polyester material located at the interior of the yarn  32  will make little to no contact with fibers of other bundles and may make little to no contact with an object, such as a person&#39;s skin, or an exterior environment, such as air. As a result, the desired characteristics of many individual fibers either directly or through interaction with fibers of other shapes, will have little impact on the features of the fabric that the yarn  32  is used to make. Moreover, a fabric made with yarns of different polymers, such as Nylon and polyester, and/or yarns of different fiber configurations, such as round and trilobal fiber shapes for example, can be expensive to produce. These types of fabrics requiring the use of different yarns and/or multiple-shape-fiber yarns can be expensive because they require the production of different fibers that require the use of multiple spinnerets and multiple yarn forming steps. In addition, as noted above, with the current state of yarn manufacturing, the yarns that must be used will create relatively heavy fabrics, which may be undesirable for a variety of desired fabric functionalities including, but not limited to, cooling fabrics. For example, a fabric made with a 150 Denier yarn may have certain desired functionality, such as effective wicking, but it may be simply too heavy to be desirable for use by consumers. 
     Current fabrics utilizing multiple yarns to achieve multiple functions have had inherent quality, weight and consistency issues, for example, which are detrimental to developing the exact fabrics desired by consumers. Since the multiple yarns being used are usually produced by different yarn manufacturers, most often they consist of different polymers. In the spinning process of the blending of yarns, made with different polymers, there is often tension, bane, weight and uneven dyeing issues that have to be addressed through further and, therefore more expensive, processing. 
     It has also been a surprising discovery that in the production of a hybrid yarn comprising a plurality of fibers of different fiber shapes extruded from a common spinneret there is a difficulty in getting the fibers to stand off sufficiently from one another as they change from the fluid state to the solid state. They end up sticking together when the fibers are shaped as shown in  FIG. 2 . As a result, desired qualities embodied in a hybrid yarn formed of an integration of fibers of different shapes are not realized due to the clumping of fibers that occurs prior to fiber solidification. It is difficult to engineer spacing of adjacent fibers from one another such as through texturing when those adjacent fibers are joined together. What is needed is a fabrication method and spinneret port configuration that ensures desired fiber shapes are made and that those fibers remain sufficiently spaced from one another by avoiding clumping early in the fabrication process. 
     SUMMARY OF THE INVENTION 
     The present invention is a yarn and fabrics made of the yarn of the present invention. One or more methods of making such a yarn are also disclosed. The yarn of the present invention is formed of a plurality of fibers of a plurality of different compositions. Each fiber composition is selectable to produce a desired functionality of the yarn. For purposes of this invention, a fiber composition may be a particular fiber cross sectional shape, a particular material of the fiber or a combination of the two. It is to be understood that the term “fiber” as used in describing the present invention includes staple fibers and filaments. The fibers are interspersed with one another in a selectable way throughout the yarn to further enable the desired functionality. That is, rather than having sets of fibers bundled together so that fibers of different types may contact each other only at the bundle periphery while the bulk of adjacent fibers are of the same type, individual fibers of different compositions may be positioned adjacent to one another so that their interaction for a desired functionality can be fully realized. 
     This is accomplished with the present invention by dispensing fiber material through a single spinneret to produce fibers of different configurations. Those fibers of different configurations exiting the spinneret are then textured, such as by fully drawn texturing or false twist texturing, for example, so that they are homogenized and intimate with one another when bundled together to produce the yarn of the present invention. That is, rather than have a yarn with sections of different fiber configurations adjacent to one another only at their periphery in a heterogeneous arrangement, the yarn is a homogeneous arrangement of fibers of different configurations that are in contact with, or integrated or intimate with, each other throughout the yarn and not just at section periphery. Having fibers of different configurations combined homogeneously yields a yarn with better open spacing between fibers than exists in a heterogeneous arrangement. Improved spacing of fibers improves the technical features of the yarn for better moisture management throughout a fabric made with such a yarn. 
     Fibers of the yarn of the present invention that are lobed; that is, the ones that are formed with tips, such as W-shaped, X-shaped and Y-shaped, for example, that may have an inclination to stick together and clump with adjacent fibers exiting the spinneret as they begin to cool, are configured in the present invention to reduce the possibility that such sticking will occur. In particular, they are fabricated to have rounded tips rather than straight tips as represented in the prior art fiber representations of  FIG. 2 . By minimizing sticking of adjacent fibers, there is an improved chance that optimal spacing of adjacent fibers will occur when the yarn is textured, and the fibers are combined in a homogeneous arrangement as described. 
     In one example of the method of making the fibers of the hybrid yarn of the present invention, a polymeric material used to make synthetic fibers is passed through a spinneret that includes ports with three or more cross sectional configurations. The number and type of ports is selectable, and the specific locations of each port is selectable so that filaments of desired cross sections, including different cross sections, may be positioned adjacent to one another in the yarn to be formed. In that configuration, the spinneret is configured with rounded ends for all fiber cross sections that have tips. In the case of a W-shaped port, the peaks of the “W” are all rounded rather than squared off. The same goes for ports for X configurations and Y configurations but not limited to those configurations. This flexibility of fiber selection using a single spinneret for multiple fiber configurations enables selection of fabric functionality and the ability to achieve such flexibility using a finer yarn than would otherwise be required using conventional yarns. The goal of a lightweight highly functional fabric is accomplished with the yarn of the present invention and forming fibers with rounded tips aids in accomplishing that functionality for those fibers having ends by minimizing adjacent fiber attachment and thereby enhancing fiber spacing in the yarn after texturing. 
     Functional characteristics of the yarn that may be managed by yarn construction through selection of particular fiber cross sections, fiber materials, fiber quantities and fiber configuration combinations include, but are not limited to, control of fluid through a fabric made of the yarn, the feel of such a yarn and the structural integrity of the yarn. For example, in regard to fluid control, the yarn may be constructed to wick moisture that contacts the yarn, enable evaporation of moisture that contacts the yarn and/or regulate the transportation of fluid passing through a fabric made with the yarn. It is noted that fluid control for the purpose of the present invention means the transport of a liquid, a gas or a combination of the two. A fabric may be made using the present yarn or a combination of yarns that includes as at least one of the combinations the present hybrid yarn as described herein. 
     The fabric may be made to perform with improved fluid transport regulation, such as drying, cooling or moisture retention capability, or a combination thereof, for example, based on the yarn construction. That is, the yarn may be formed of a plurality of fiber compositions that facility fluid transport regulation dependent on the material used to make the fibers and the cross-sectional shape of the fibers and/or the fiber materials that are used to make the yarn. Without limiting the options for fiber choices in making the yarn of the present invention and as examples only, a fiber with substantial perimeter surface area, such a W-shaped fiber with rounded tips, for example, may be used to facilitate wicking, while a voided fiber, such as a partially or completely hollow fiber, for example, may be used to regulate fluid transport through the fabric. As a further example, the yarn may be formed so that fibers of different cross sections and/or different fiber materials are each located at its perimeter, at its center or integrated in a homogenous manner throughout the yarn&#39;s cross section dependent on the desired functionality of the fabric to be made with the yarn. 
     For a hybrid yarn of the present invention made of a single synthetic material with three or more fiber cross sections, a spinneret with a plurality of port shapes of three or more different cross section shapes may be used to form the initial filaments, provided the shapes with tips are made with rounded tips. The filaments of different cross-sectional shapes are either cut to a shorter length or used as is in the process of completing formation of the yarn, which may include texturing of the fibers exiting the spinneret in a manner known to those of skill in the art, such as by fully drawn texturing or false twist texturing to form a hybrid yarn comprised of polymer fibers of different cross sections interspersed with one another throughout the yarn, with each fiber having its particular characteristics. Another example hybrid yarn of the present invention includes the homogenization of fibers of a plurality of synthetic materials, each of which may comprise one or more fiber cross sections. The yarn may be finalized in a manner known to those skilled in the art of yarn production after the fibers of different configurations have been homogenized and made intimate within the yarn. The characteristics of individual fibers can be taken advantage of in the yarn of the present invention on a finer scale than is possible with the prior yarns in which fibers of different types only interface at the outer surfaces of the distinct bundles. That is, the yarn of the present invention may be made with a lower Denier than otherwise required to achieve a desired functionality. 
     The yarn of the present invention is made by a new yarn making method. In particular, fibers of different configurations are combined with one another to combine them in a selectable way prior to any final yarn processing. For example, if the different fiber configurations comprise fibers of three or more different cross sections, a hybrid spinneret may be used to form the initial distinct filaments. If the different fiber compositions comprise fibers of different materials, individual fibers may be integrated with one another prior to final formation of the yarn. In either case, it may not be necessary to use as many spinnerets as previously used in making synthetic fibers and at least one additional twisting step may be eliminated. In the simplified example depicted in  FIG. 1 , it was necessary to use twisters  18 ,  28 ,  38  and  40  to produce yarn  42 —a yarn with less than complete integration of the three filament types  16 ,  26  and  36 . For the example of a hybrid yarn of the present invention made of a single synthetic material and fibers of three or more different cross sections, the fluid synthetic material can be passed through a single spinneret with ports of three different cross section configurations. The filaments exiting the spinneret can be twisted together, for example, using only one twister, that being the equivalent of twister  40 . That eliminates the need for the process steps associated with using twisters  18 ,  28  and  38 . The process of the present invention involves the use of less equipment and fewer processing steps, and reduces production errors, equipment costs and maintenance requirements to make an improved hybrid yarn. 
     The present invention further provides for the production of better fabrics using hybrid yarns of the present invention. As noted, specific characteristics may be identified and established in a fabric primarily through yarn fiber selection and construction. As one example and without intending to be limiting, if a goal is to make a fabric that provides moisture wicking, moisture circulation, moisture exhaustion out of the fabric and fabric softness, a single yarn could be made to achieve that goal. The single yarn can be made with technically shaped fibers to provide the indicated characteristics. For example, a first fiber with a first cross section may be used for moisture exhaustion (i.e., evaporation) from the fiber and/or wicking of moisture, a second fiber with a second cross section different from the cross section of the first fiber may be used for fluid transport through the fabric, and a third fiber with a third cross section different from the cross section of the first two fibers may be used for fabric softness. Whereas the prior art would have required three or more different yarns to provide all of those functions in a fabric, the present invention enables the manufacture of such a fabric using a single yarn including fibers with three or more different cross sections provided fibers with tips are made with rounded tips. As noted, the fibers of that single yarn are better interspersed than with a multi-yarn version, thereby improving the characteristics of the yarn and doing so with a finer yarn. It can be seen that interspersing fibers of different materials and/or different configurations greatly enhances yarn functionality options, better control over yarn manufacture and, ultimately, fabric manufacturing and quality consistency. 
     The present invention is a yarn formed with fibers of different compositions, whether different cross sections, different materials or a combination of the two. If the yarn is made of a single material, the fibers are of at least three different cross sections. The yarn can be used to make functional textiles through fabric formation, such as by weaving or knitting, for example. The type of knitting that may be used includes, but is not limited to, circular knitting, warp/weft knitting, flat knitting, and other types of knitting known to those of skill in the field of fabric production. 
     The hybrid yarn of the present invention enables the production of a fabric product with multiple functions using one or more yarns. Because the fabric includes at least the present hybrid yarn, there is far greater fabric consistency and the other limitations of prior production efforts are eliminated. This innovation includes the ability to combine this newly created multi-cross-sectional yarn along with the spinning/winding of a totally different yarn to create a final fabric of desired functionality. Whether such fabrics are made with the present hybrid yarn only or a combination of yarns that includes the present yarn, they can be used in many end uses including, but not limited to apparel and footwear. 
     This engineering of an at least one yarn system technology can take place at two distinct times during the yarn making process: 1) a design of a multi-cross-sectioned spinneret, where the newly created extrusion process allows for an integrated combination of multiple-different cross-sections (three or greater) to create a yarn of Denier (size) and count (fiber) that is made of the same synthetic material; 2) a combination of different fibers of different materials, which may be synthetic or natural materials; or 3) a combination of 1) and 2). The different fiber compositions are combined in an integrated manner prior to final yarn formation. These combined fibers of different Denier, fiber or spun count, functionality and end use (when knit or woven into a fabric) provide for optimum programmable performance, without any of the inconsistencies resulting from additional processing steps and/or different material sources as noted above. 
     This yarn of the present invention may be engineered for a wide range of desired functionalities embodied in fabrics made using the yarn. One example is that of managing fluid transport through the fabric. In respect of that example, wicking, drying, cooling or any combination thereof may be effectively managed using the hybrid yarn. The flexibility of functionality is achieved with a newly created yarn that can be used as a stand-alone (no second or third yarn required unless other functionalities deem it desirable to make such a combination) that will produce all types of knit and woven fabrics, from a simple single jersey, pique, double knit or other exotic constructions or as a simple plain-woven fabric or as a complicated woven Jacquard. 
     Although other yarns have previously been developed with multiple cross sections, this new development allows for the inclusion of all sorts of fiber configurations including fibers with one or more voids located through the fiber cross section at least partially or completely through the fiber. One example of a fiber with a void located through the cross section is a hollow fiber as is known to those skilled in the art. Other versions of fibers with voids through the cross section through at least a portion of the length of the fiber are also known by those skilled in the art. An advantage of the present invention is to make any such completely or partially voided fibers having tips to make those fibers with rounded tips rather than squared tips prior to contacting those fibers with one another and with other fibers. The integration of different fiber compositions throughout the yarn enables fabric functionality management without chemical treatment that is better than exists with current fabrics. 
     Most existing garments touted as having moisture management characteristics, for example, move moisture directly from the skin to the surface with little transportation management or regulation taking place. This results in wet areas (saturation) in the chest, underarms and the lower back while leaving much of the garment dry. The hybrid yarn of the present invention allows for the production of a fabric that creates a personal environment that enables the movement of fluid throughout the garment in a desired manner, including by transporting the fluid to all areas of the garment. During and after extreme physical exercising, this may leave the garment damp for a short period of time but no signs of long-lasting saturation and discoloration and since the fluid, such as moisture, is distributed more evenly across the garment, drying time is accelerated. This innovation is engineered to provide fabrics with chemical-free fluid management as well as other desired performance characteristics. Because the yarn of the present invention may be chemical-free, unlike most counterparts, washing will not deteriorate the performance of the technology. The use of the present yarn in the manufacture of a fabric also allows for the manufacture of lighter weight fabric while achieving desired functional characteristics. 
     These and other advantages of the present invention are further disclosed in the following detailed description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified representation of the primary components and steps associated with the prior art for making a synthetic yarn formed with three different filament types. 
         FIG. 2  is a simplified cross section representation of a portion of a prior yarn made of the three different filament types pursuant to  FIG. 1 . 
         FIG. 3  is a simplified representation of the primary components and steps associated with the process for making a synthetic hybrid yarn of the present invention formed with three different filament cross sections using a single spinneret. 
         FIG. 4  is a representation of a set of example filament cross sections representing fiber cross sections with tips wherein the tips of those fibers are rounded. 
         FIG. 5  is a simplified front face view of a hybrid spinneret of the present invention suitable for use in making a hybrid yarn of the present invention with at least partially hollow (voided) fibers, W-shaped and Y-shaped fibers, wherein the W-shaped and the Y-shaped fibers have rounded tips. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION 
     A hybrid yarn of the present invention includes a plurality of fibers with the plurality of fibers including a plurality of different fiber compositions wherein there may be three or more different fiber compositions. The different fiber compositions may be three or more different fiber cross sections formed of the same material such as a synthetic material. The different fiber compositions may be different filament materials. The different fiber compositions may be a combination of different materials and different cross sections. The plurality of fibers are combined together in a texturing process so that the fibers of different compositions are interspersed among themselves so that they are integrated with one another in a selectable yarn construction. Those fibers having tips are made so that the tips are rounded. 
     The hybrid yarn including the three or more different fiber cross sections can be made with a single synthetic material such as a polymeric material such as polyester or Nylon, for example. That single polymeric material may be used to form the fibers. As noted, fibers made of other materials, such as other polymeric materials and/or natural materials, may be combined with the fibers of different cross sections of the single synthetic material. A fiber composition of the present invention may also include the use of fibers of natural materials including, for example, cotton 
     Spun yarns having the plurality of fibers with a plurality of different fiber compositions interspersed throughout the yarn also forms part of this invention. Continuous filament yarns produced by various hybrid spinneret designs such as those disclosed herein can be cut into staple fiber and then spun into spun yarns when a spun yarn is required, as is known by those skilled in the field of making spun yarns. The spun yarns created, may consist solely of the staple fibers produced from the filaments extruded through the spinneret or they may be combined with other fibers to produce the spun yarns desired. In these cases, natural fibers such as cotton or wool may be used as part of the blend of the spun yarn. Other fibers such as polyamide or aramid fibers may be used as part of the blend. The blend of fibers used to produce multi-function spun yarns is not limited to the fibers just mentioned herein but is based strictly on the characteristics desired in the final product. 
     A process for making an example of a hybrid yarn  102  of the present invention made using a single polymeric material with three or more different cross sections is shown in simplified form in  FIG. 3 . In a first step of the process, the polymeric material, such as polyester, for example, from source  112  is melted and passed through a spinneret  114  to generate polyester filaments  116 . In this example, spinneret  114  includes a plurality of ports of three different cross sections, including a first cross section, a second cross section and a third cross section, through which liquefied polyester passes, wherein tipped cross sections are rounded at the ends so as to impart that shape to the filaments passing therethrough. The polyester filaments  116  comprise first-shaped filaments  122 , second-shaped filaments  124  and third-shaped filaments  126  interspersed with one another. 
     The spinneret  114  has three different port cross sections selected based on the desired characteristics of the yarn to be produced. Examples of the types of filament cross sections with rounded tips that may be fabricated are represented in  FIG. 4 . The invention is not limited to those fiber shapes shown in  FIG. 4 . These and other filament cross sections may be produced using spinnerets with portals having corresponding cross sections, provided that those with tips are made with rounded tips. In a second step of the process, the filaments  122 ,  124  and  126  are cooled and joined together, such as by twisting them together on twister  128  to produce the yarn  102 . Prior to that twisting, the filaments  122 ,  124  and  126  are drawn, textured or otherwise modified, or a combination thereof to integrate the different fibers together so that the combination is homogeneous and adjacent fibers of different configurations are intimate with one another while also minimizing their adherence to one another. The filaments  122 ,  124  and  126  may be cut to form them into staple fibers. The resultant yarn  102  has fibers of different configurations integrated with one another as a function of the number and location of the spinneret portals associated with each of the different fiber cross sections. That is, they are not distinct and separate bundles of fibers that simply contact one another at their periphery. Other ways of making a yarn known to those of skill in the art may be used to make the hybrid yarn of the present invention with a single polymeric material, provided they enable selectable positioning of three or more different fiber cross sections for the fibers making up the yarn and provided texturing steps homogenize the combination of different fiber configurations. 
     The process of making the filaments so that the desired fiber shape is maintained and the filaments with tips have rounded tips and adjacent fibers stand off from one another sufficiently in the transition from liquid to solid material involves the selection of the rate of passage of the liquified material through the spinneret ports, the viscosity of the liquified material, the sizes of the ports, the temperature of the material, and the rate of cooling with a cooling medium, such as air, the material upon passing through the spinneret ports. The formed filaments may be texturized as is known in the art. 
     Hybrid yarns of different configurations can be made using a process similar to that generally disclosed herein with respect to  FIG. 3 . The particular configuration of the hybrid spinneret employed with selectable portal constructions, and polymeric material selected will dictate the specific characteristics of any hybrid yarn of interest made using a single synthetic material. A spinneret comprising a plurality of ports wherein there are three or more different spinneret port cross sections is provided to form mixed fiber hybrid yarns. The different spinneret ports can be provided at any selected ratio, and any types of cross-sectional fiber geometries can be formed (e.g., multi-lobal, mixed multi-lobal, fully voided, partially voided and round, for example). Fibers with voids through the cross section for at least a portion of the fibers may comprise between about 15% and about 85% of the total fiber count of the hybrid yarn. The fibers of the hybrid yarns may be otherwise manufactured using existing techniques beginning with the polymer selected, its pre-spinneret processing and any post-spinneret filament processing, such as cutting into staple fibers, without deviating from the present invention. The present invention includes the formation of spinnerets that produce the hybrid yarns of the present invention. That is, by specifying particular yarn constructions, the construction of corresponding spinneret configurations is also established. 
     A fabric made from a hybrid yarn of the present invention may be made using one or more materials. The fabric may be single-ply or multi-ply. The fabric may be made by weaving or knitting, for example. Any other processes known to those of skill in the art of making a fabric from a yarn may also be used to make a fabric of the present invention and that fabric may be further processed as desired. The fabric may be made with any of a variety of functional characteristics dependent on the fiber compositions selected and the yarn construction made using the selected fiber compositions. For purposes of this invention, the yarn construction refers to the particular fiber positioning and numbers. The fiber positioning may be controlled by spinneret design and/or fiber integration. 
     An example of a fabric of the present invention made with a hybrid yarn of the present invention may be made with any one or more of the following characteristics: (1) it cools when exposed to a fluid, such as perspiration from an individual&#39;s body, for example, and/or it cools a surface, such as an area of the body, for example; (2) it is able to wick (transport) perspiration, water or other fluid from an object such as an individual&#39;s skin so as to dry the object; (3) it is able to absorb a fluid at a weight that is a plurality of the weight of the fabric so as to act as an absorbent; (4) it efficiently regulates the evaporation rate of fluid retained within the fabric while also enabling extended cooling of an underlying surface such as the skin of a person; (5) it controls moisture release, that is, it provides moisture management; and (6) is reusable, while retaining all of these characteristics from use-to-use. The example fabric has one or more of these characteristics using a hybrid yarn of the invention without requiring additional chemicals, if none are desired, to provide satisfactory fluid transport characteristics. Beyond that, a fabric made with the yarn of the present invention may have one or more other desired characteristics, such as a comfortable feel, fire retardancy or anti-microbial, to name a few examples, wherein the yarn is made to incorporate filaments of different types, materials, treatments or shapes with the three or more synthetic filaments such that the additional incorporated filaments impart the desired functionality to the yarn and, thus, to a fabric made with that yarn. That is, minerals, metals and other materials may also be incorporated into the yarn of the present invention, whether in fiber or other form, to impart or enhance desired characteristics of a fabric made with the present yarn. 
     A fabric made from the hybrid yarn of the present invention may be used for thermoregulation. That is, it may be fabricated with one or more hybrid yarns selected to have filaments arranged to enable the control of movement of fluid through the fabric. The characteristics of the hybrid yarn alone may provide the desired thermoregulation characteristics of the fabric. In addition, the fabric may be modified mechanically to enhance and/or complement the inherent thermoregulation characteristics of the yarn. For example, and without limitation, the fabric may be made with a hybrid yarn to regulate the movement/transportation of fluid from the surface of an object to the core of the fabric&#39;s construction and through the opposite side of the fabric. The yarn may be constructed to move fluid away from the object, allow the fluid to dwell in the fabric and then exit the fabric if cooling is desired. This may be accomplished using first yarn fibers that wick fluid, second yarn fibers that transport the fluid relatively quickly through the fabric and third yarn fibers that provide evaporative characteristics, for example. Alternatively, the yarn may be constructed to retain fluid within the fabric, such as air that is warmed as a result of being retained, when warming is desired. This may be accomplished with first yarn fibers that wick fluid, second yarn fibers that extend fluid dwell time within the fabric and third yarn fibers that limit evaporation, for example. 
       FIG. 5  illustrates a simplified representation of a hybrid spinneret having a configuration for producing a hybrid yarn formed of a plurality of first cross section fibers, second cross section fibers and third cross section fibers, in which the cross sections are different from one another. The filaments formed by passing polymeric material through the spinneret are then texturized so that they are homogenized and intimate with one another throughout the resultant yarn that is made. Three different portal types are represented, including one at least partially voided type having no tips, and two different tipped configurations, wherein the tips of those two types are rounded. The portal shapes, number of different portal shapes and the arrangement of the portals of the spinneret are chosen based on the desired characteristics of a fabric made with the yarn formed using fibers from the spinneret and/or other combinations of fibers that are interspersed throughout the yarn. The spinneret of  FIG. 5  is one example and is not intended to limit the scope of the invention, provided that tipped fiber shapes have rounded ends of the spinneret portals. It was a surprising discovery that a hybrid yarn formed of an integrated combination of different fiber shapes has desirable characteristics when tipped fibers have rounded tips. That is, the inclusion of rounded tips reduced the chance that adjacent fibers would adhere to one another and improving resultant open spacing among the fibers. Spinnerets with different configurations may be used to produce hybrid yarns of different configurations and resultant characteristics. The number of portals of each of the different portal shapes may be equal or they may be different. The number of portals is also selectable. The ability to make such hybrid yarns enables the manufacture of fabrics of lighter weight and better functionality than has previously been possible. 
     A fabrication method of the present invention suitable for forming a fabric of the invention using one or more hybrid yarns of the present invention includes a plurality of steps, several of which are optional, in the fabrication of the fabric. In the first step, the fabric is formed by weaving or knitting one or more yarns including one or more hybrid yarns of the present invention. For purposes of the description of the present invention, the two terms may be used interchangeably, such that when it is stated that the method includes a weaving step, that means weaving or knitting the yarn(s). In optional steps, the fabric may be sized and/or pre-treated to prepare it for subsequent dyeing and/or printing on either or both of its front and back sides, for example, or for any other purpose. The fabric may also be brushed, peached or sheared and it may be tentered. 
     The skilled artisan will recognize that the fabric of the present invention may be used for any one or more of a large variety of purposes and to partially or wholly form any one or more of a large variety of products. For example, the fabric may be used to partially or wholly form apparel or non-apparel products such as towels, facecloths, shirts, pants, jackets, shorts, vests, ties, footwear, gloves, bandanas, hats, handkerchiefs, underwear, hosiery, bras, and bandages. Further, these products may be designed for recreational, exercise, medical, and military use, for example. For example, the fabric may be used to form a towel that is to be sold or otherwise distributed to individuals who will be exposed to hot temperatures for a long period of time, such as patrons of an outdoor theme park, beachgoers, or athletes, for example. As another example, the fabric may wholly or partially form a compress that may be wetted and placed on the forehead of an individual having an elevated body temperature for the purpose of keeping the individual cool. Regardless of how and for what reason such an example fabric of the present invention is to be used, however, it is especially useful for being included to wholly or partially form a product that is meant to provide instant and/or extended cooling to its user. 
     The hybrid spinneret of the present invention may be used to make hybrid yarns that can in turn be used to make improved fabrics and improved fabric products. The use of hybrid yarns comprising a plurality of fibers of which there are a plurality of fiber compositions interspersed together in a selectable way throughout the yarn enable the fabrication of fabrics with selectable functionality, such as improved fluid transport regulation, that has not been possible. For example, a yarn that is configured to emphasize drying may be formed with a certain fiber configuration. As another example, a yarn that is configured to emphasize wicking may be formed with a different fiber configuration. Further, a yarn that is configured to emphasize thermoregulation may be formed with a third fiber configuration. Corresponding different spinneret configurations may be used to produce those different yarn configurations when the yarn is configured of the same material or is configured with a plurality of materials of which at least one has fibers of a plurality of cross-sectional shapes wherein cross-sectional shapes with tips have rounded tips. It is also to be noted that the use of these optional hybrid spinnerets also reduces the cost and quality variability associated with the prior fabrication methods in which multiple spinnerets and multiple twisters were required to make the yarns necessary to produce fabric characteristics as described herein. Additionally, it is to be noted that lighter weight fabrics with selectable functionality can be produced as an aspect of the present invention. 
     The present invention has been described with respect to various examples. Nevertheless, it is to be understood that various modifications may be made without departing from the spirit and scope of the invention as described by the following claims.