A method of preparing a continuous yarn from comingled discontinuous glass fiber and thermoplastic fiber is described. An exemplary yarn comprising comingled recycled glass fiber and acrylic fiber is described. Methods of preparing fiber-reinforced composite components from the yarn are also described. The fiber-reinforced composite components can be used in a variety of applications. In an exemplary application, the composite is used to provide component parts for a model rocket body and nosecone.

A method for a fiber bundle, including a heating process of Joule-heating the fiber bundle by energization between at least a pair of electrodes. The fiber bundle is carried in contact with the electrodes and has electrical conductivity at least between the electrodes. At least one of the electrodes has an aggregating structure that aggregates the fiber bundle while being in contact with the outer surface of fiber bundle. The aggregating structure has a trench or cylindrical shape with a structural surface that narrows in the depth direction. When the electrodes are each composed of a rotating body, the aggregating structure is a trench provided on the outer surface of the rotating body. The trench has a bottom surface that narrows toward a rotation center side. The trench may have a widened portion on the outer peripheral edge side. The widened portion guides the fiber bundle to the bottom surface.

Carbon fiber and method of forming the same are provided. The method modifies proportion of a finishing oil to control a relation between a surface tension and a particle size of the finishing oil, and thus penetration of the finishing oil into an interior of the carbon fiber is avoided. Therefore, the carbon fiber can have both low oil residues and a high strength.

The invention relates to a method for thermally stabilizing melt-spun PAN precursors. For this purpose, the invention provides a continuous method for producing a thermally stabilized multifilament thread made of a meltable copolymer of polyacrylonitrile (PAN), wherein a pre-stabilized multifilament thread is thermally stabilized and in the process at least temporarily stretched. The invention additionally relates to a thermally stabilized multifilament thread which can be obtained according to a corresponding method and to a carbon fiber which is made of the correspondingly thermally stabilized multifilament thread.

The invention relates to a method for thermally stabilizing melt-spun PAN precursors. For this purpose, the invention provides a continuous method for producing a thermally stabilized multifilament thread made of a meltable copolymer of polyacrylonitrile (PAN), wherein a pre-stabilized multifilament thread is thermally stabilized and in the process at least temporarily stretched. The invention additionally relates to a thermally stabilized multifilament thread which can be obtained according to a corresponding method and to a carbon fiber which is made of the correspondingly thermally stabilized multifilament thread.

A device and a method for manufacturing a synthetic yarn, in which at least two yarn plugs (1), (2), (3) are produced by texturing, are placed in a first zone (A) on the cooling surface (6c) of a rotating cooling drum (6), moved to a second zone (B) and form more than one winding (I),(II), in which the yarn plugs are kept in the second zone (B) by a gas stream (F.sub.B) on the cooling surface (6c), and in which no gas stream or a less powerful gas stream is generated in an intermediate zone (C) in order to prevent the yarn plugs (1), (2), (3) from leaving the second zone (B).

A process for manufacturing a fiber including polyetherketoneketone including the steps of: mixing polyetherketoneketone and sulfuric acid having a concentration of at least 90 wt % to obtain a spin dope and passing the spin dope through a spinneret into a coagulation bath, wherein the polyetherketoneketone is dissolved in the sulfuric acid to a concentration of 12 to 22 wt %. Also disclosed are fibers obtainable by the process and polyetherketoneketone fibers having a sulfur content of 0.001 to 5 wt %, based on the weight of the fiber, in particular such fibers having low or high crystallinity, as well as, hybrid yarns and composite materials.

A process for manufacturing a fiber including polyetherketoneketone including the steps of: mixing polyetherketoneketone and sulfuric acid having a concentration of at least 90 wt % to obtain a spin dope and passing the spin dope through a spinneret into a coagulation bath, wherein the polyetherketoneketone is dissolved in the sulfuric acid to a concentration of 12 to 22 wt %. Also disclosed are fibers obtainable by the process and polyetherketoneketone fibers having a sulfur content of 0.001 to 5 wt %, based on the weight of the fiber, in particular such fibers having low or high crystallinity, as well as, hybrid yarns and composite materials.

A method for producing a flame-proofed fiber by performing a flame-proofing treatment on a carbon-fiber precursor fiber bundle with a heat treatment furnace including a gas supply blowout nozzle, including: a nozzle body including an inclined plate that guides a gas flowing straightly from a gas inlet port to a rectification board; and the rectification board which rectifies the flow of the gas to blow out toward a yarn from a gas outlet port, where a gas introduction direction in the nozzle is different from a gas blowing out direction, a gas guiding zone is between the inclined plate and the rectification board and includes a guide plate in a space between the gas inlet port and the rectification board and divides the gas supplied from the inlet port into two or more streams, and at least one of between the inclined plate and the guide plate or between the guide plates, an upstream passage width W1 perpendicular to a gas flowing direction inside the gas passage and any downstream passage width W2 satisfy W1W2.

A method for producing a flame-proofed fiber by performing a flame-proofing treatment on a carbon-fiber precursor fiber bundle with a heat treatment furnace including a gas supply blowout nozzle, including: a nozzle body including an inclined plate that guides a gas flowing straightly from a gas inlet port to a rectification board; and the rectification board which rectifies the flow of the gas to blow out toward a yarn from a gas outlet port, where a gas introduction direction in the nozzle is different from a gas blowing out direction, a gas guiding zone is between the inclined plate and the rectification board and includes a guide plate in a space between the gas inlet port and the rectification board and divides the gas supplied from the inlet port into two or more streams, and at least one of between the inclined plate and the guide plate or between the guide plates, an upstream passage width W1 perpendicular to a gas flowing direction inside the gas passage and any downstream passage width W2 satisfy W1W2.