KR20040048369A - Temperature adaptable textile fibers and method of preparing same - Google Patents

Abstract

The present invention provides fibers with improved heat storage and release properties. The fiber comprises a mixture of heat stabilizing material surrounded by a first polymer and a second polymer forming the sheath of the fiber. The heat stabilizing material may be one or more phase change and / or plastic crystalline materials. The first polymer serves as a carrier for the heat stabilizing material during the formation of the fiber, and both the first and second polymers effectively incorporate the heat stabilizing material into the fiber to prevent its leakage. The fibers can be sheath-core or “sea-sea” type, and fabrics made from these fibers exhibit improved insulating properties in the desired temperature range. Also disclosed is a method of making a fabric formed from the fiber and various types of fibers.

Description

Temperature-adaptive textile fiber and its manufacturing method {TEMPERATURE ADAPTABLE TEXTILE FIBERS AND METHOD OF PREPARING SAME}

The use of phase change materials for the storage or release of thermal energy has long been known. The phase change material may be repeatedly converted into a solid phase and a liquid phase, or may be thermocycled, using latent heat of fusion to absorb, store and release heat during this phase inversion. The latent heat of fusion for phase change materials is greater than the sensible heat capacity. As an example, in phase change materials, the amount of energy absorbed on melting or released on freezing is much higher than the amount of energy absorbed or released upon increasing or decreasing the temperature of the material above 10 ° C. Upon melting and freezing, the phase change material absorbs and releases substantially more energy per unit weight than the sensible heat storage material, which is heated or cooled over the same temperature range. In contrast to sensible heat storage materials which absorb and release energy essentially uniformly over a wide temperature range, the phase change material absorbs and releases large amounts of energy near its melting / freezing point.

Other useful materials with high heat storage and release properties are generally referred to as plastic crystalline materials. These materials have an effective thermal energy, for example, without undergoing a phase change from solid to liquid. The precise reason why these plastic crystalline materials exhibit this thermal behavior before the change of state is not clear, but the thermal effects of these materials are thought to be caused by structural and / or rotational disorder in these materials. In any case, it has been found that plastic crystalline materials, such as polyhydric alcohols, are effective in providing thermal insulation to textile fibers, which can be found in US Pat. No. 4,781,615, which is incorporated herein by reference in its entirety.

Phase change materials and plastic crystalline materials have been used in a variety of applications, including inserting into textile fibers for the purpose of keeping the garment at a comfortable temperature. In these textile applications, attempts have been made to coat such materials on fibers; However, this makes it impossible to use a sufficient amount of material to provide effective thermal properties in clothing or other articles formed from fibers. It has been attempted to micro-encapsulate the phase change material as part of the blend in the fiber. However, microcapsules do not have the structural integrity required to withstand the forces applied on the encapsulated phase change material during the extrusion of the fibers.

One particular application of phase change materials to textile fibers is disclosed in Sayler 5,885,475. The above disclosure is incorporated herein by reference in its entirety. Salyer discloses fiber materials containing fiber forming polymers having phase change materials incorporated throughout the polymer. Silica is also incorporated into Salyer's fibers in order to fix the phase change material with a stable gel to prevent the phase change material from leaking in the course of the phase change at its melting / freezing point. However, the addition of silica does not absolutely guarantee the integrity of the fiber upon melting the phase change material.

Thus, at present, a textile fiber comprising an amount of phase change material or plastic crystalline material exhibiting effective thermal insulation to the fiber, which can be easily produced by extrusion, ensures that the material remains firmly in the fiber. There is a need for provision.

The present invention relates to a fiber composition containing a core polymer mixed with a phase change material sealed in a polymer sheath, such that the fiber stores or releases heat during temperature changes of the surrounding environment.

1 is a schematic side view of a typical spunbond web forming apparatus used to form the fibers of the present invention.

2 is a perspective view including a cross section of the sheath-core fiber of the present invention.

3 is a perspective view including a cross section of an island-in-the-sea fiber of the present invention.

Detailed description of the preferred embodiment

The present invention relates to a polymer fiber having an internal polymer component containing a first polymer fiber composition mixed with a heat stabilizing material, and a second polymer fiber composition surrounding the mixture and forming an outer or sheath of the fiber. The term "heat stabilizer" is defined herein to encompass both phase change materials as well as plastic crystalline materials used in the present invention. The fiber may be a sheath-core structure wherein the first polymer mixed with the heat stabilizing material forms a core and the second polymer forms the sheath of the fiber. Alternatively, the fibers may have a “sea-sea” structure, wherein a plurality of mixtures of the first polymer and the heat stabilizing material are substantially elongated in the longitudinal direction of the fiber, are separated from each other, surrounded by the second polymer, Form an "island" in the "sea" which is the second polymer.

The first and second polymers may each be any existing material used to make textile fibers. Examples of such fibrous materials are polyolefins such as polyethylene or polypropylene, polyamides such as nylon, polyesters and the like, as well as copolymers, trimers and combinations thereof. The first and second polymers may be elastomers such as polyurethanes. Preferably, the first and second polymers may be one of polyethylene, polypropylene or mixtures thereof.

Phase change materials useful in the present invention include any material in which the phase change occurs in the range of the desired temperature and has a latent heat of fusion that is greater than its sensible heat capacity. Any plastic crystalline material that exhibits heat storage or release properties within the preferred temperature range is also useful in the present invention. Preferably, the heat stabilizing material is compatible or nonreactive with the second or sheath polymer. The heat stabilizing material may or may not react with the first polymer. In either case, such materials preferably retain their phase change or heat storage / release properties at the desired temperature after mixing with the first polymer. Phase change materials used in the present invention will have a phase change temperature in the range of about -5 ° C to about 125 ° C. Similarly, the plastic crystalline material of the present invention will store or release heat within the same temperature range. In many apparel applications, the preferred phase change or plastic crystalline material will undergo phase change or exhibit heat storage / release properties between about 22 ° C. and about 28 ° C.

The choice of particular phase change material will depend upon the desired phase change temperature and the particular application of the fiber. As an example, a phase change material having a melting point close to room temperature would be desirable in applications such as apparel designed to incorporate bonded fibers into the fabric to maintain a comfortable temperature for the user while the climate changes slightly. Particularly useful phase change materials known in the art are long chain straight-chain paraffinic hydrocarbons, typically having a C ₁₀ to C ₄₄ range. The length of the carbon chain is correlated with the melting point of the material. As an example, n-octacoic acid contains 28 straight chain carbon atoms per molecule and has a melting point of 61.4 ° C. In comparison, n-tridecane contains 13 straight chain carbon atoms per molecule and has a melting point of -5.5 ° C. N-octadecane containing 18 straight chain carbon atoms per molecule is particularly preferred in most apparel applications because its melting point is 28.2 ° C.

Another useful phase change material is polyethylene glycol, the melting point of which can change depending on the molecular weight change of the glycol. Polyethylene glycol (Carbowax 600) having a molecular weight range of 570 to 630 has a melting point of 20 to 25 ° C., making it useful for most garment applications. Other polyethylene glycols that may be useful at other temperatures include Carbowax 400 (melting point 4-8 ° C.), Carbowax 1500 (melting point 44-48 ° C.) and Carbowax 6000 (melting point 56-63 ° C.). Another phase change material that can be used in the present invention is polyethylene oxide (melting point range 60-65 ° C).

Effective plastic crystalline materials useful in the present invention are polyhydric alcohols. Preferred polyhydric alcohols are pentaerythritol, 2,2-dimethyl-1,3-propanediol, 2-hydroxymethyl-2-methyl-1,3-propanediol, or 2-amino-2-methyl-1,3 Amino alcohols such as propanediol.

Heat stabilized materials can be used individually or in combination with a single or multiple fibers of the present invention. The choice of one or more heat stabilizing materials will depend on the intended use of the fabric formed by the fibers comprising such materials, as well as the ability to retain their heat storage and release properties after repeated thermal cycling of the selected materials. A full range of sheath-core and "seaweed" fibers is possible under the present invention. As an example, one sheath-core fiber embodiment may consist of a single heat stabilizing material and a core mixture of core polymers contained within the polymer sheath. In another embodiment, the core polymer may contain two or more different heat stabilizing materials mixed with the core material. Depending on the selected heat stabilizing material and their reactivity with each other, the combination of two or more heat stabilizing materials in the fiber core may be It will result in improved thermal energy storage and release properties in fibers and fabrics formed from such fibers. A mixture of two different phase change materials in the fiber core, for example, can cause the fiber to exhibit two distinct phase change temperature points when the phase change materials are nonreactive with one another. Alternatively, phase change materials may react to cause altered phase changes, which may be useful in certain applications.

Fibers containing blends of different heat stabilizing materials will be useful in a variety of applications where it may be desirable for the fabric to exhibit improved thermal insulation properties in two or more distinct temperature ranges. By way of example, the fabric used to make gloves may be composed of the fibers of the present invention containing phase change materials A and B, wherein phase change material A has a melting point of about 5 ° C., and phase change material B is It has a melting point of about 75 ° C. The combination of these phase change materials in the core of the sheath-core fiber forming the glove is not only in a cold environment (eg when used outside during winter), but also in a warm environment (eg, an heated object such as an oven tray). Will provide gloves with improved thermal insulation properties.

Alternatively, the fabric can be made from a plurality of sheath-core fibers, wherein two or more fibers contain different heat stabilizing materials in their cores. The fabric may, for example, consist of a sheath-core fiber containing a certain percentage of the first heat stabilizing material and a sheath-core fiber containing the remaining percentage of the second heat stabilizing material. Additionally, the "sea islands" fibers of the present invention may contain one or more "islands" containing one or more different heat stabilizing materials as compared to other "islands" within the same fiber. It is possible for a vast number of different fiber combinations using one or more heat stabilizing materials to provide a fabric with improved thermal insulation properties in a wide range under the present invention.

The provision of “islands” or core polymers in the fibers of the present invention is essential when such fibers are formed to serve as carriers for heat stabilizers. Without the addition of "islands" or core polymers, the heat stabilized material will not be able to maintain core integrity on its own during the fiber processing step in a typical fiber extrusion apparatus. In addition, the resulting fibers will be much weaker and less effective for use in fabric fabric without the addition of internal polymers providing a support.

On the contrary, it is desirable to provide a sufficient amount of heat stabilizing material for the fibers of the present invention in order to maximize the thermal energy storage and release properties of such fibers, thus maximizing the improved insulation of the fabric formed from such a plurality of fibers. . Depending on the specific materials used to form the fiber, the amount of core or "island" polymer can be increased in relation to the shell polymer, thereby increasing the amount of heat stabilizing material that can be transported in the fiber, while the fiber strength The threshold of can be maintained. The inventors have found that the resulting weight ratio of the heat stabilizing material in the core or "island" mixture amounts to about 50% and that the weight ratio of the core or "island" mixture in the total fibers also reaches about 50%. It was determined that it would provide effective thermal insulation and strength to the The use of this weight ratio provides fibers with up to about 25% by weight heat stabilized material.

The fibers of the invention can be made using melt spinning processes or solution spinning processes (wet or dry). In each process, fibers are formed by extruding the material forming the fibers through a plurality of small orifices of spinnerets to form filaments coming out of the orifices. The term "spinner" refers to the part of an extrusion apparatus that delivers polymer and phase change and / or plastic crystalline material through an orifice to the outside environment for extrusion. A typical spinneret may contain 1000 to 5000 orifices per meter of spinneret length. The spinneret may be drilled or etched into a plate or any other structure capable of draining the required fiber stream. In the melt spinning process, the polymeric material delivered to the orifice is in a tacky molten state. Heat stabilized materials are typically liquid at polymer melt temperatures. Prior to passing through the spinneret orifice, the heat stabilizing material is mixed with the first polymer to form a core of the sheath-core fiber or a "island" of "sea island" fibers. The mixing will disperse and microencapsulate a portion of the heat stabilizing material throughout the first polymer. Some of the heat stabilizing material that is not fully encapsulated in the first polymer will still be included by the second polymer as it exits the spinneret and thus will be effectively sealed in the resulting fiber.

In a solution spinning process, the polymeric material of the fiber is dissolved in a solvent before passing through the spinneret orifice. In a wet spinning process, the spinneret is immersed in a chemical bath whereby polymeric material precipitates out of solution and solid fibers form as it exits the spinneret. In the dry spinning process, the polymeric material exits the spinneret in the air and solidifies with a solvent (eg, acetone) melt in the air. Solution spinning processes are known in the art and can also be used to form the fibers of the present invention as they can produce sheath-core and "seaweed" fibers.

After exiting the spinneret, the extruded fiber is typically drawn or stretched using a godet and / or an aspirator. By way of example, the extruded fibers exiting the spinneret in the melt spinning process are directed downward, in the form of a vertical curtain, at least partially quenched before being introduced into an elongated slot air intake underneath the spinneret. Form a moving strand. The intake air provides a rapidly downward moving air stream generated by compressed air from one or more air intake jets. The air stream creates an elongation on the fiber, causing the fiber to elongate between the spinneret and the air jet, thus making the fiber thinner. During the spinning process of this portion of the fibers of the invention, the shell and core or "island" polymers solidify. The heat stabilized materials may only partially solidify for a while due to the temperature at which the liquid or fiber emerges, but are effectively sealed in the polymer sheath as well as the microcapsules formed in the first polymer, substantially preventing these materials from leaking or leaking from the fibers. do.

The fibers of the present invention can be used in any fiber application known in the art to form various types of fabrics or nonwovens. By way of example, the drawn fibers may be wound onto bobbins or other winding mechanisms for forming a fabric using any existing knitting or weaving technique. Alternatively, the fibers may be placed randomly on a forming surface such as a moving conveyor screen belt (eg, Fourdrinier wire) to form a continuous nonwoven web of fibers. The web can then be joined using one of several known techniques to form a stable, nonwoven for use in the manufacture of various textile products. A common bonding method involves lifting a web from a moving screen belt and passing the web between two heated calender rolls. Often, one of the rolls is embossed, creating a lot of spots in the web to be joined. Air carded or spun-laid webs can also be formed from such polymeric fibers. Staple fibers can also be made to practice the invention, wherein the fibers are cut into short fibers before forming a web therefrom. One possible advantage of employing staple fibers is that more isotropic fabrics can be formed, because staple fibers can potentially be oriented more randomly on the web than continuous fibers.

1 schematically depicts an apparatus 10 for producing sheath-core or “sea-sea” fibers comprising one or more heat stabilizing materials, in accordance with an exemplary embodiment of the present invention. The apparatus further adds the fibers to a spunbond process to produce a nonwoven with the selected thermal insulation. The term "spunbond" refers to a process of forming a web from a filament made by extruding a molten polymer from an orifice of a nonwoven or thin melt spun polymeric fiber or spinneret.

The apparatus of FIG. 1 includes a spin pack 28 for extruding and shaping fibers. As used herein, the term "spin pack" refers to an assembly for processing molten polymer to produce an extruded polymer stream, which includes final polymer filtration, distribution system, and spinneret. Spin packs suitable for forming shell-core, "seaweed" and other multicomponent fiber structures are known in the art. By way of example, one such spin pack is disclosed in US Pat. No. 5,162,074, which disclosure is incorporated herein by reference in its entirety. In essence, such spin packs provide flow paths for two or more polymers, creating a filament coming from the spinneret orifice, comprising core or "island" polymers surrounded by a polymer sheath.

Apparatus 10 includes hoppers 12 and 14 which receive pellets of two different polymers, shell polymer A and core or “island” polymer B. These two polymers are fed to the screw extruders 16 and 18 through the hoppers 12 and 14, respectively, which melt as they are conveyed towards the heating tubes 20 and 22. The heat stabilizing material C may be added at any position of the apparatus 10 and mixed with the polymer B before encountering the polymer A in the spinneret 30. Some examples are provided in Figure 1 showing the addition of material C to polymer B in apparatus 10 at other points. As an example, material C is moved from position 13 to hopper 14, or to a screw extruder. It may be added in solid or liquid form at position (19) at (18). Alternatively, material C may be added at position 27 in spin pack 28.

Mixing of the heat stabilizing material with the core polymeric material can be made in one of static or dynamic ways. Dynamic mixing can take place by any mechanical means, such as screw extruder 18, that effectively mixes the components. As an example, when a phase change material is added to the hopper 14 or screw extruder 18, dynamic mixing occurs as the stream moves in the extruder 18 in the direction of the heating tube 22. As polymer B and material C are heated to the melting temperature of polymer B, the two components are effectively mixed.

Unlike dynamic mixing, static mixers do not use any mechanical shaking or mixing means. Rather, the mixing takes place by crossing the paths of two or more moving streams of different materials, in the molten or liquid state, and the desired dispersion of each material in one or more streams by crossing a sufficient number of times. Static mixers used to form extruded fibers containing two or more mixed polymers are known in the art. One example of such a static mixer is disclosed in US Pat. No. 5,851,562, which is incorporated herein by reference in its entirety. Static mixing may occur at any other location within the device prior to combining with the shell polymer in the spin pack 28 or at the spinneret. By way of example, in apparatus 10, heat stabilizing material C may be added at position 21 and statically mixed with polymer B while moving in heating tube 22.

Depending on the heat stabilized material selected and its corresponding melting temperature during mixing, the heat stabilized material may have a viscosity that varies significantly depending on the core or "island" polymer. By way of example, at the polymer melting temperature, the core or "island" polymer may be in a very sticky molten state, while the heat stabilized material is less sticky and liquid. The heat stabilizing material may or may not be uniformly dispersed in the core or "island" polymer after mixing. Regardless of the degree of dispersion, the resulting fiber will have effective heat storage and release properties if a sufficient amount of heat stabilizing material is encapsulated within the fiber.

The molten polymer flows into the metering pumps 24 and 26 through the heating tubes 20 and 22, respectively. The pump feeds two polymer streams to the spin pack 28 having suitable internal components that can form a sheath-core or “seaweed” fiber structure. In the apparatus of FIG. 1, the spin pack 28 includes a spinneret 30 with an orifice 32, which forms the sheath-core fiber extruded through it. The array 34 of sheath-core fibers exits the spinneret 30, which is pulled downwards and tapered by the intake 36, which is supplied with compressed air or steam from the tube 38. The intake air may be in the form of a gun or slot, for example, and may extend across the entire width of the fiber arrangement, ie in a direction corresponding to the width of the web to be formed by the fiber.

The intake 36 delivers the tapered fibers 40 onto the web-forming screen belt 42 that is supported and driven by the rolls 44, 46, and 50. Suction box 48 is connected to a fan (not shown) to draw ambient air through screen belt 42, which causes fiber 40 to form a nonwoven web on screen 42. The formed nonwoven web can then be further processed to form the desired fabric, clothing or other textile products endowed with the thermal properties of the combined fibers of the present invention.

2 shows a cross-sectional view of a typical sheath-core fiber 100 of the present invention, which can be made by the apparatus of FIG. 1. The fiber 100 contains a phase change material dispersed throughout the core polymer 120 of the fiber 100. The sheath 110 surrounds the periphery of the fiber 100 and thus prevents the phase change material portion from escaping from the fiber in the thermocycle between the liquid and solid phases. The 130 portion represents the phase material portion that lies between the core polymer 120 and the shell polymer 110. Core polymer 120 surrounds or encapsulates any phase change material portions present therein with respect to the core of fiber 100, such as portion 140, to prevent these portions from escaping from the fiber.

3 shows a cross-sectional view of a typical “seaweed” fiber 200 of the present invention, which may also be produced by the apparatus of FIG. 1. The sheath or “sea” 210 of the fiber 200 surrounds the “islands” 220, 230, 240, and 250. Four "islands" are shown for illustrative purposes only, and the "sea islands" fibers of the present invention may contain more or fewer "islands" depending on the particular application of the fibers. "Isles" 220, 230, 240, and 250 contain "island" polymers 222, 232, 242, and 252, respectively. Some such as heat stabilized material portions may be incorporated within their respective "islands" or between "islands" and "oceans". Fiber 200 contains two different forms of heat stabilizing material. "Isles" 220 and 250 contain the same heat stabilizing material as shown in part 260, and "Isles" 230 and 240 are the same heat stabilizing material as shown in part 270. It contains. The heat stabilized material sealed in the 270 portion is different from the heat stabilized material sealed in the 260 portion.

The preferred embodiments of the novel improved fibers of the present invention and methods of making them have been described, and it is contemplated that other variations, modifications and variations can be made to those skilled in the art based on the teachings herein. Accordingly, all such modifications and variations are considered to be within the scope of the present invention as defined by the appended claims. Certain terms are used herein, but they are used in a general and descriptive sense and not for purposes of limitation.

Summary of the Invention

Accordingly, in view of the above, and also for other reasons which become evident as the present invention is fully described, the object of the present invention comprises a sufficient amount of phase change or plastic crystalline material throughout the fiber, and by extrusion It is to provide a textile fiber that can be easily manufactured.

It is another object of the present invention to provide a fiber which secures a phase change or plastic crystalline material safely in the fiber, so that the phase change material is prevented from leaking when the melting point phase change proceeds.

It is another object of the present invention to provide a fiber which can maximize the amount of phase change material or plastic crystalline material in the fiber while maintaining the overall fiber strength and the manufacturing ability by extrusion.

Another object of the present invention is to provide a sheath-core and an "island-in-the-sea" containing at least one phase change or plastic crystalline material in order to further improve the thermal insulation properties of the fibers. "To provide a method for producing the fibers.

It is a further object of the present invention to provide a fabric made from the fibers of the invention containing one or more phase change or plastic crystalline materials.

The above objects are achieved in the present invention by providing a fiber composition containing a blend or mixture of phase change or plastic crystalline material encapsulated within the core polymer and the polymer shell. The core and shell polymers of the present invention may be any number of polymers including, but not limited to, polyolefins, polyamides, polyesters, and the like, and copolymers, trimers, and combinations thereof. The core and shell polymer may also be an elastomer such as polyurethane. Preferred materials for both the core and the shell are polyethylene, polypropylene or combinations thereof. Any phase change or plasticity at a preferred temperature, preferably having a melting point or heat storage / release point in the range of about −5 ° C. to about 121 ° C., and maintaining such melting or heat storage / release point when mixed with the core polymer. Crystalline materials can be used. Typical phase change materials that can be used and readily blended with the core polymers of the present invention are long chain paraffinic hydrocarbons, polyethylene oxides and polyethylene glycols. Plasticizable crystalline materials useful in the present invention are polyhydric alcohols.

The fiber composition of the present invention can be prepared by a melt spinning process, where the fibers are extruded to form a core polymer and a phase change material encased in an outer skin polymer upon exiting the extruder. do. The fiber composition may also be prepared using a solution spinning process. The fibers formed in the present invention may be shell-core or “sea-sea” type and may be incorporated into various types of textile fabrics. Each fiber may contain blends of phase change materials or plastic crystalline materials to improve the thermal properties of the fiber. Alternatively, fabrics containing the fibers of the present invention having different phase change materials or plastic crystalline materials can be produced.

The fiber compositions of the present invention can be repeatedly heat cycled, storing and releasing a sufficient amount of heat, to provide a fabric formed from such fibers having improved thermal properties for a significant period of time. The fibers formed in accordance with the present invention also maintain a complete seal of the interior material to prevent phase change or leakage or leakage of the plastic crystalline material when thermally circulated.

Claims (43)

Fibers with improved heat storage and release properties containing: At least one internal composition extending substantially in the longitudinal direction of the fiber and containing a mixture of a first polymer and a heat stabilizing material; And A sheath surrounding the inner composition, forming the outside of the fiber, and containing a second polymer. The fiber of claim 1 wherein the first and second polymers are each selected from the group consisting of polyolefins, polyamides, polyesters, elastomers, and combinations thereof. The fiber of claim 2 wherein the first and second polymers are each polyolefin selected from the group consisting of polyethylene, polypropylene, and combinations thereof. The fiber of claim 1 wherein the heat stabilizing material stores or releases heat at a temperature within the range of about −5 ° C. to about 125 ° C. 3. The fiber of claim 4 wherein the heat stabilizing material stores or releases heat at a temperature within the range of about 22 ° C. to about 28 ° C. 6. The fiber of claim 4 wherein the heat stabilizing material is a phase change material selected from the group consisting of C ₁₀ -C ₄₄ paraffinic hydrocarbons, polyethylene oxides, polyethylene glycols, and mixtures thereof. The fiber of claim 4 wherein the heat stabilizing material is a plastic crystalline material. The fiber of claim 4 wherein the one or more internal compositions comprise two or more different heat stabilizing materials. The fiber of claim 1 wherein the composition weight of the heat stabilizing material in the one or more internal compositions amounts to about 50%. The fiber of claim 1 wherein the composition weight of the heat stabilizing material in the fiber amounts to about 25%. The fiber of claim 1 wherein the heat stabilizing material portion is encapsulated within the first polymer. The fiber of claim 1, wherein the one or more internal compositions are a single internal composition that defines a core in the fiber. The fiber of claim 1 wherein the fibers comprise a plurality of internal compositions that are separated from one another and surrounded by an outer sheath. The fiber of claim 1 wherein the fiber is one of continuous fiber and staple fiber. Sheath-core fibers containing: A core located substantially in the longitudinal direction of the fiber and extending in the longitudinal direction, the core containing a mixture of the core polymer and the heat stabilizing material; A polymeric sheath forming an outer side of the fiber and surrounding the core. 16. The fiber of claim 15 wherein the core and shell polymer are each selected from the group consisting of polyolefins, polyamides, polyesters, elastomers, and combinations thereof. The fiber of claim 16, wherein the core and shell polymer are each polyolefin selected from the group consisting of polyethylene, polypropylene, and combinations thereof. 16. The fiber of claim 15 wherein the heat stabilizing material is a phase change material selected from the group consisting of C ₁₀ -C ₄₄ paraffinic hydrocarbons, polyethylene oxides, polyethylene glycols, and mixtures thereof. The fiber of claim 15 wherein the heat stabilizing material is a plastic crystalline material. The fiber of claim 15 wherein the core comprises a core polymer and a mixture of two or more different heat stabilizing materials. Island-in-the-sea fibers containing the following; A plurality of islands located substantially in the longitudinal direction of the fiber and extending in the longitudinal direction, wherein the islands are each separated from each other and contain a mixture of island polymer and heat stabilizing material; A polymer shell forming an outer side of the fiber and surrounding each of the islands. The fiber of claim 21 wherein the island polymer and the shell polymer are each selected from the group consisting of polyolefins, polyamides, polyesters, elastomers, and combinations thereof. The fiber of claim 22 wherein each of the island polymers and the polymer shell is a polyolefin selected from the group consisting of polyethylene, polypropylene, and mixtures thereof. 22. The fiber of claim 21 wherein the heat stabilizing material is a phase change material selected from the group consisting of C ₁₀ -C ₄₄ paraffinic hydrocarbons, polyethylene oxides, polyethylene glycols, and mixtures thereof. 22. The fiber of claim 21 wherein the heat stabilizing material is a plastic crystalline material. 22. The fiber of claim 21 wherein the at least one island comprises a mixture of island polymers and at least two different heat stabilizing materials. 22. The fiber of claim 21 wherein the heat stabilizing material of at least one island is different from the heat stabilizing material of at least one other island. The fiber of claim 21 wherein the two or more islands contain different island polymers. A method of making a fiber containing a heat stabilizing material, comprising: Mixing the heat stabilizing material with the first polymer to form a mixture; Combining the mixture with a second polymer in a spin pack of a fiber extrusion machine such that the second polymer surrounds the mixture; Extrude the mixture and the second polymer from a spinneret of the spin pack to form a fiber having an outer side formed of the second polymer and an inner side including the mixture surrounded by the second polymer. The method of claim 29, further comprising: Prior to the mixing step, a heat stabilizing material is added to the first polymer, wherein the heat stabilizing material and the first polymer are each in liquid or solid form. The method of claim 29, wherein the mixing step comprises: Providing a first liquid stream of heat stabilizing material; Providing a second liquid stream of the first polymer; And intersecting said first and second liquid streams a predetermined number of times to make a desired mixture of said heat stabilizing material and said first polymer in at least one of said liquid streams. The method of claim 29, further comprising: Forming a plurality of separate mixtures, where each mixture contains a heat stabilizing material and a first polymer; Combining the plurality of separated mixtures with a second polymer in a spin pack such that the second polymer surrounds the plurality of separated mixtures; Extrude the plurality of separated mixtures and the second polymer from a spinneret to form a fiber having an outer side formed of the second polymer and an inner side comprising the plurality of separated mixtures surrounded by the second polymer . 33. The method of claim 32, wherein the one or more separate mixtures comprise different stabilizing materials than the one or more separate other mixtures. 29. The method of claim 28, wherein the extruding step is performed by one of a melt spinning process and a solution spinning process. 29. The method of claim 28, further comprising attenuating the fibers formed during the extrusion step. 36. The method of claim 35, further comprising the step of thinning, then combining the fiber with other fibers to roll the fiber onto bobbins or to form a non-woven web. . In a fabric containing a plurality of fibers blended together, the at least one fiber exhibits heat storage and release properties, and a fabric containing: A mixture of a heat stabilizing material and a first polymer, the mixture extending substantially in the longitudinal direction of the fiber; A polymeric sheath forming the outside of the fiber and surrounding the mixture. 38. The fabric of claim 37, wherein the mixture comprises two or more different heat stabilizing materials. 38. The fabric of claim 37, wherein the fabric contains a plurality of fibers exhibiting heat storage and release properties, and at least one of the plurality of fibers comprises a heat stabilizing material different from at least one other of the plurality of fibers. Fabric. 38. The fabric of claim 37, wherein the at least one fiber comprises a plurality of separate mixtures surrounded by a polymer sheath. 41. The fabric of claim 40, wherein the at least one separated mixture comprises a different heat stabilizing material than the at least one other separated mixture. 38. The fabric of claim 37 wherein the plurality of fibers are blended together by one of a weaving process and a nonwoven process. 38. The fabric of claim 37 wherein the plurality of fibers are blended together by a spunbond process.