The present invention relates to an acrylic fiber for artificial hair containing an acrylic copolymer. The fiber cross-section of the acrylic fiber has one or more shapes selected from the group consisting of a C-shape, a figure-6-shape, and a broad bean-shape with a hollow portion. Two ends of the C-shape, the figure-6-shape, or the broad bean-shape are apart from each other or are in contact with each other. A circumcircle of the fiber cross section has a diameter of 70 m or more and 100 m or less, an inscribed circle of the fiber cross section has a diameter of 15 m or more and 50 m or less, the thickness of the fiber cross section is 13 m or more and 40 m or less, and the canal width between the ends of the fiber cross section is 0 m or more and 15 m or less.

A method of recycling polymers and other plastics comprises: (A) grinding recycled PET bottles (or other suitable recycled polymer) into a group of flakes; (B) washing the flakes; (C) identifying and removing impurities, including impure flakes, from the group of flakes; (D) passing the group of flakes through an MRS extruder while maintaining the pressure within the MRS portion of the MRS extruder below about 5 millibars; (E) passing the resulting polymer melt through at least one filter having a micron rating of less than about 50 microns; and (F) preparing the polymer melt for recycling into a new product. In various embodiments, the above process may be utilized in the recycling of, for example, polytrimethylene terephthalate (PTT), polypropylene, polyvinyl chloride (PVC), high-density polyethylene (HDPE), polystyrene (PS), expanded polystyrene (EPS), or any other suitable polymer or plastic.

A fiber for artificial hair having a plurality of single fibers, in which the single fibers each contain (A) a vinyl chloride polymer, (B) an aromatic vinyl polymer, and (C) a (meth)acrylic acid-based polymer, a content of the component (B) is more than 0% by mass and 50% by mass or less on the basis of the total amount of the component (A) and the component (B), a content of the component (C) is more than 0% by mass and 8% by mass or less on the basis of the total amount of the component (A) and the component (B), and a coefficient of variation of fineness of the single fibers is 35 or less.

A fiber for artificial hair having a plurality of single fibers, in which the single fibers each contain (A) a vinyl chloride polymer, (B) an aromatic vinyl polymer, and (C) a (meth)acrylic acid-based polymer, a content of the component (B) is more than 0% by mass and 50% by mass or less on the basis of the total amount of the component (A) and the component (B), a content of the component (C) is more than 0% by mass and 8% by mass or less on the basis of the total amount of the component (A) and the component (B), and a coefficient of variation of fineness of the single fibers is 35 or less.

The present invention provides artificial hair having a fluffy and voluminous shape by being immersed in hot water. The artificial hair includes a fiber cord in which one or a plurality of fiber bundles are braided, helically wound, or fixed at intervals with a plurality of fixtures, and has a configuration in which the fiber bundle includes at least first fibers and second fibers having different softening temperatures, and the fiber cord has a plurality of processing regions in a middle section in a longitudinal direction, and in the fiber cord, the number of the processing regions is five or more, and the arithmetic average length of the plurality of processing regions in the longitudinal direction in a suspended state is 0.7 cm or more and 6 cm or less.

The present invention provides artificial hair having a fluffy and voluminous shape by being immersed in hot water. The artificial hair includes a fiber cord in which one or a plurality of fiber bundles are braided, helically wound, or fixed at intervals with a plurality of fixtures, and has a configuration in which the fiber bundle includes at least first fibers and second fibers having different softening temperatures, and the fiber cord has a plurality of processing regions in a middle section in a longitudinal direction, and in the fiber cord, the number of the processing regions is five or more, and the arithmetic average length of the plurality of processing regions in the longitudinal direction in a suspended state is 0.7 cm or more and 6 cm or less.

A method for separating fibers that separates a modacrylic fiber, a polyvinyl chloride fiber and a polyester fiber and a method for producing fibers using these fibers obtained by the method for separating fibers are provided. A method for separating fibers contained in a fiber mixture from the fiber mixture, includes a step of mixing the fiber mixture containing at least two selected from a modacrylic fiber, a polyvinyl chloride fiber and a polyester fiber, and a liquid mixture containing calcium chloride, a nonionic surfactant and water. A method for producing a fiber includes a separation step of mixing a fiber mixture containing at least two selected a modacrylic fiber, a polyvinyl chloride fiber and a polyester fiber, and a liquid mixture containing calcium chloride, a nonionic surfactant and water, and a step of spinning a raw material obtained from a fiber separated in the separation step.

A method for separating fibers that separates a modacrylic fiber, a polyvinyl chloride fiber and a polyester fiber and a method for producing fibers using these fibers obtained by the method for separating fibers are provided. A method for separating fibers contained in a fiber mixture from the fiber mixture, includes a step of mixing the fiber mixture containing at least two selected from a modacrylic fiber, a polyvinyl chloride fiber and a polyester fiber, and a liquid mixture containing calcium chloride, a nonionic surfactant and water. A method for producing a fiber includes a separation step of mixing a fiber mixture containing at least two selected a modacrylic fiber, a polyvinyl chloride fiber and a polyester fiber, and a liquid mixture containing calcium chloride, a nonionic surfactant and water, and a step of spinning a raw material obtained from a fiber separated in the separation step.

A method of manufacturing carbon fiber includes (a) preparing a solution by mixing a raw material containing at least one chlorine group in the side chain of a repeat unit with a solvent, (b) forming a fibrous material by spinning the solution, (c) forming a ladder-like chemical ring structure in the fibrous material by hydrothermally treating the fibrous material with a hydrochloric acid solution at a predetermined temperature for a predetermined time, and (d) carbonizing the result of step (c).

A method of manufacturing carbon fiber includes (a) preparing a solution by mixing a raw material containing at least one chlorine group in the side chain of a repeat unit with a solvent, (b) forming a fibrous material by spinning the solution, (c) forming a ladder-like chemical ring structure in the fibrous material by hydrothermally treating the fibrous material with a hydrochloric acid solution at a predetermined temperature for a predetermined time, and (d) carbonizing the result of step (c).