Multi-component fibers having enhanced reversible thermal properties and methods of manufacturing thereof

#The present invention relates to synthetic fibers having enhanced reversible thermal properties. More particularly, the present invention relates to multi-component fibers comprising phase change materials and to the formation of such fibers via a melt spinning process or a solution spinning process.

#Many fabrics are made from synthetic fibers. Conventionally, two processes are used to manufacture synthetic fibers: a solution spinning process and a melt spinning process. The solution spinning process is generally used to form acrylic fibers, while the melt spinning process is generally used to form nylon fibers, polyester fibers, polypropylene fibers, and other similar type fibers. As is well known, a nylon fiber comprises a long-chain synthetic polyamide polymer characterized by the presence of an amide group—CONH—, a polyester fiber comprises a long-chain synthetic polymer having at least 85 percent by weight of an ester of a substituted aromatic carboxylic acid unit, and a polypropylene fiber comprises a long-chain synthetic crystalline polymer having at least 85 percent by weight of an olefin unit and typically having a number average molecular weight of about 40,000 or more.

#The melt spinning process is of particular interest since a large portion of the synthetic fibers that are used in the textile industry are manufactured by this technique. The melt spinning process generally involves passing a molten polymeric material through a device that is known as a spinneret to thereby form a plurality of individual synthetic fibers. Once formed, the synthetic fibers may be collected into a strand or cut into staple fibers. Synthetic fibers can be used to make knitted, woven, or non-woven fabrics, or alternatively, synthetic fibers can be spun into a yarn to be used thereafter in a weaving or a knitting process to form a synthetic fabric.

#For a better understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.

#FIG. 1 illustrates enlarged cross sectional views of various exemplary multi-component fibers according to some embodiments of the invention.

#FIG. 2 illustrates a three-dimensional view of an exemplary core/sheath fiber according to an embodiment of the invention.

#The present invention relates to multi-component fibers comprising one or more phase change materials and methods of manufacturing thereof. Multi-component fibers in accordance with various embodiments of the invention have the ability to absorb or release thermal energy to reduce or eliminate heat flow. In addition, such multi-component fibers may exhibit improved processability (e.g., during manufacturing of the fibers or of a product made therefrom), improved strength, improved containment of a phase change material within the fibers, or higher loading levels of the phase change material. The multi-component fibers may be used or incorporated in various products to provide a thermal regulating property while providing improved strength to the products. For example, multi-component fibers in accordance with embodiments of the invention may be used in textiles (e.g., fabrics), apparel (e.g., outdoor clothing, drysuits, and protective suits), footwear (e.g., socks, boots, and insoles), medical products (e.g., thermal blankets, therapeutic pads, incontinent pads, and hot/cold packs), containers and packagings (e.g., beverage/food containers, food warmers, seat cushions, and circuit board laminates), buildings (e.g., insulation in walls or ceilings, wallpaper, curtain linings, pipe wraps, carpets, and tiles), appliances (e.g., insulation in house appliances), and other products (e.g., automotive lining material, sleeping bags, and bedding).

#In conjunction with the thermal regulating property provided, multi-component fibers in accordance with various embodiments of the present invention when incorporated, for example, in apparel or footwear may provide a reduction in an individual's skin moisture, such as, due to perspiration. For instance, the multi-component fibers may lower the temperature or the relative humidity of the skin, thereby providing a lower degree of skin moisture and a higher level of comfort. The use of specific materials and specific apparel or footwear design features may further enhance this moisture reduction result.

#A multi-component fiber according to some embodiments of the invention may comprise a plurality of elongated members. According to some embodiments of the invention, the multi-component fiber may comprise a fiber body formed from the plurality of elongated members. The fiber body typically will be elongated and may have a length that is several times (e.g., 100 times or more) greater than its diameter. The fiber body may have a variety of regular or irregular cross sectional shapes such as, by way of example and not by limitation, circular, multi-lobal, octagonal, oval, pentagonal, rectangular, square-shaped, trapezoidal, triangular, wedge-shaped, and so forth. According to some embodiments of the invention, two or more of the elongated members (e.g., two adjacent elongated members) may be joined, combined, united, or bonded to form a unitary fiber body.