Abstract: A vertical heating apparatus for production of graphite fibers from preoxidized fibers or carbon fibers comprises of a tubular heating element which generates heat by high frequency induction. A heat-insulating material layer surrounds the tubular heating element coaxially. The layer is composed of carbon particles having specific grain diameters and angles of repose. A high frequency induction unit is provided around the heat-insulating material layer also in a coaxial relation thereof.

Abstract: A strand prepreg which comprises (i) a resin composition comprising 100 parts by weight of thermosetting resin having a softening point of 60.degree. C. or less and about 5 to 60 parts by weight of epoxy resin having a number average molecular weight of 5,000 or more and (ii) about 20 to 80% by volume strands of carbon fibers, glass fibers, aromatic polyamide fibers and the like, wherein the strands are impregnated with the resin composition.

Abstract: A process for producing preoxidized fiber spun yarns is described comprising subjecting an acrylonitrile fiber tow to a preoxidation, applying a surface active agent, stretch cutting without crimping, crimping to form slivers, processing in a gilling step, and spinning; according to this process, short fibers and powders of fibers are formed to a lesser extent, and nebs, slubs and flies, etc. are caused to a lesser extent, and preoxidized fiber spun yarns having high quality are obtained in a high yield.

Abstract: A process for producing activated carbon fibers of high adsorption capacity which comprises oxidizing an acrylonitrile based fiber, wherein the acrylonitrile based fiber is a homopolymer of acrylonitrile, a copolymer containing about 60% by weight or more of acrylonitrile, or a mixture of polymers such that about 60% by weight or more of acrylonitrile is present in the mixture, in an oxidizing atmosphere at a temperature of about 200.degree. C. to about 300.degree. C. while applying a tension to the fiber until the amount of bonded oxygen reaches about 65% to about 95% of the saturated amount of bonded oxygen of the fiber, wherein the tension applied is such that the shrinkage of the fiber during oxidation reaches about 70% to about 90% of the degree of free shrinkage at the same temperature, and then activating the fiber.

Abstract: A brake pad or lining comprising a binder and a peroxidized fiber derived from an acrylic fiber said peroxidized fiber containing at least about 5 wt % bonded oxygen. The material has a relatively high coefficient of friction as well as good wear resistance and fade resistance and can be used in place of a conventional asbestos brake pad or lining.

Abstract: A process for producing activated carbon fibers comprising subjecting an acrylonitrile based fiber to oxidation processing in an oxidizing atmosphere at a temperature of about 200.degree. C. to about 300.degree. C. while applying a tension to the fiber until the amount of bonded oxygen reaches about 50% to about 90% of the saturated amount of bonded oxygen followed by activation processing.

Abstract: A light insole, with a high modulus of elasticity, which has a shank comprising a fiber-reinforced resin sheet and which is produced by putting a shank element on an insole element and heating under pressure to mold the sheet and adhere the sheet to the insole element.

Abstract: A method for forming a uniformly mixed fibrous mat which comprises feeding a continuous high tensile modulus reinforcing fibrous material and a pre-cut thermoplastic fibrous material with a lower melting point or softening point than the temperature at which the reinforcing fibrous material melts or is damaged to a rotating rotor which is provided with projections to thereby cut the continuous fibrous material and pluck the pre-cut fibrous material, dispersing the thus treated fibrous materials into an air flow to mix the same and thereafter collecting the resulting mixed materials on a net to yield the mat. The product can thereafter optionally be compressed under heat to melt only the thermoplastic fibrous material to thereby consolidate the mat.

Abstract: An acrylic carbon fiber with excellent thermal oxidation resistance, which contains 50 ppm or more of a phosphorus component (as phosphorus) and/or a boron component (as boron) and which contains 100 ppm or more of a zinc component (as zinc) and/or a calcium component (as calcium), and which suffers a fiber weight reduction of about 20% or less upon standing for 3 hours in air at 500.degree. C.

Abstract: A tobacco smoke filter capable of selectively removing irritating materials and unpleasant bitter components from tobacco smoke and containing as a filter element nitrogen-containing activated carbon fibers produced by oxidizing acrylonitrile polymer fibers and then activating the oxidized fibers.

Abstract: An assembly, useful in producing a carbon fiber-reinforced metal, of a plurality of carbon fibers each coated with a matrix metal layer, the fibers having bonded points at the metal layers to form a two-dimensional network structure or both a two-dimensional network structure and a three-dimensional network structure, produced advantageously by an ion plating process or a vacuum deposition process.

Abstract: A process for producing carbon fibers which comprises feeding an inert gas into a vertical furnace at about 500 to about 1,000.degree. C. and into a transverse furnace at about 800 to about 2,000.degree. C. connected thereto so that the inert gas flows from the transverse furnace toward the bottom of the vertical furnace and then to the top of the vertical furnace, and feeding preoxidized fibers from the top of the vertical furnace to pass the fibers countercurrent to the inert gas flow through the two furnaces to thereby carbonize the fibers. Apparatus of the type shown in the drawing for the production of carbon fibers by the above process. Carbon fibers having good performance can be produced with good efficiency.

Abstract: A process for continuously producing carbon fibers which comprises preoxidizing polyacrylonitrile fibers containing at least about 90% by weight of acrylonitrile at a temperature of about 200.degree. to about 300.degree. C in an oxidizing atmosphere while allowing the fibers to shrink about 40 to about 70% (of the free shrinkage of the fibers determined under a load of 1 mg/d) with the progress of preoxidation; then carbonizing the preoxidized fibers at about 500.degree. to about 1,000.degree. C in a non-oxidizing atmosphere so that the shrinkage of the fibers finally becomes about 40 to about 70% (of the free shrinkage of the preoxidized fibers determined when the fibers are placed under a load of 1 mg/d and heated at 1,000.degree. C for 15 minutes); and then heat treating the carbonized fibers at constant length at a temperature of up to about 3,000.degree. C in a non-oxidizing atmosphere.