Abstract: A continuous precursor fiber bundle for manufacture of carbon fibers comprising a plurality of precursor fiber bundles each of which comprises at least 30,000 filaments, having a joined portion formed by joining at the terminal end of one of the precursor fiber bundles and the starting end of another one of the fiber bundles directly or through an intervening fiber bundle comprising a plurality of filaments, wherein the individual filaments at the joined portion are substantially uniformly interlaced with each other and wherein the interlacing of filaments is in a pattern selected from the group consisting of continuous substantially uniform interlacing in the transverse direction of said fiber bundles, interlacing at many joints on the joining portion, and interlacing of the entire face of said joining portion.

Abstract: A rocket motor assembly is insulated or thermally protected with a rocket motor ablative material formed from a prepreg. The prepreg contains at least an impregnating resin matrix and, as a precursor prior to carbonization, either carded and yarn-spun solvent-spun staple cellulosic fibers, solvent-spun cellulosic filaments, or a combination thereof. When patterned and carbonized, the rocket motor ablative material can be lined or otherwise placed into a rocket motor assembly, such as between the solid propellant and case, in the bulk area of the exit nozzle liner, or at susceptible portions of a re-entry vehicle, such as the nose cone.

Abstract: A composite that includes a reaction injection molded matrix into which carbon fibrils have been incorporated, and a molding composition suitable for preparing such a composite. The invention also features a composite that includes a premix in which carbon fibrils have been incorporated into a resin matrix, and the molded product of the premix.

Abstract: A method for monitoring characteristics of materials includes placing a material in an application zone, measuring a change in at least one property value of the application zone caused by placing the material in the application zone and relating changes in the property value of the application zone caused by the material to at least one characteristic of the material An apparatus for monitoring characteristics of a material includes a measuring device for measuring a property value resulting from applying a frequency signal to the application zone after placing a material in the application zone and a processor for relating changes in the property value caused by placement of the material in the application zone to at least one desired characteristic of the material. The application zone is preferably a resonant cavity.

Abstract: A method of producing a carbon-carbon part having a filamentized composite fiber substrate is provided. A substrate having a plurality of discontinuous filamentized fibers and a binder that binds said filaments together to form a composite substrate is provided, and carbon atoms are deposited onto the filaments at a predetermined temperature so that the binder is removed completely from the filaments and replaced with carbon atoms to from a dense carbon-carbon part.

Abstract: A separable tow of elongated polymeric filaments comprises a plurality of distinct sub-tows lightly and individually and separably joined, as by light crimping together along their edges or, if uncrimped, joined by presence of moisture, and capable of being packed into a container and later removed and separated. The filaments are preferably acrylic and have a total fineness of about 300,00-1,500,000 denier and the sub-tows each of which has a total fineness of about 50,000-250,000 denier, with a filament fineness of about 1-2 denier, and each sub-tow has a degree of entanglement of about 10-40 m−1 as measured by the hook drop test.

Abstract: A method and apparatus for the carbonization of polyacrylonitrile (PAN) precursor fibers. The apparatus comprises a furnace, or series of furnaces in side-by-side arrangement. Each furnace includes a heater, an air inlet and an air diffusion plate. The fiber is located in the furnace above the air diffuser plate, such that heated air is evenly dispersed over the fibers. The method generally comprises the steps of heat treating the PAN precursor in an oxidizing environment to stabilize the fiber, and then further heat treating the stabilized fiber in an oxidizing environment to carbonize the stabilized fiber. The method can be carried out in a single furnace, or can be carried out in a series of furnaces in a continuous process.

Abstract: A method of fabricating a ceramic structure as well as a pre-ceramic preimpregnated composite material incorporating a continuous woven fiber and a discontinuous fiber pre-ceramic matrix for subsequent curing and component construction. The method includes preparation of a mixture of discontinuous fibers, fillers, and a pre-ceramic precursor resin where the precursor resin is present in a quantity sufficient to substantially saturate subsequently adjacent woven fiber lengths, and thereafter introducing the mixture to a situs between an upper length of woven fiber and a lower length of woven fiber in alignment with each other while effectuating linear movement of these woven fiber lengths and moving the lengths toward each other for compression and retention in a sandwich configuration to thereby fabricate a pre-ceramic preimpregnated composite material. The material is cut to size in accord with the configuration of a part to be manufactured, formed into a green-state structure, and cured.

Abstract: An improved process is disclosed for producing a unique metals-containing anisotropic pitch suitable for carbon fiber manufacture. Soluble, aromatic-organometallic compounds are added to a carbonaceous feedstock which is substantially free of mesophase pitch and the resulting composition is heat soaked to produce an isotropic pitch product containing mesogens and soluble, aromatic-organometallic compounds. Next, the pitch product is solvent fractionated to separate mesogens which contain metals from the organometallic compounds. The metals-containing mesogens are heated to a temperature sufficient to cause fusion to produce a metals-containing mesophase pitch. In another method, the carbonaceous feedstock is heat soaked to produce an isotropic pitch product containing mesogens and high molecular weight, soluble, aromatic-organometallic compounds are added to the mesogen containing isotropic pitch product prior to solvent fractionation.

Abstract: Cellulosic single fibers such as cotton is prepared without any resins or pitches to a mass or bulk such as a lap which is self-shaped and retains its form by a force of cohesive intertanglement of fibers. The mass as prepared is heated for carbonization or graphitization, if desired, to obtain unique shaped carbides of porous and stable structures in which the cohesion of fibers is made more dense on account of the total shrinkage of the mass by carbonization.

Abstract: A process for the production of carbon fibers, including melt-spinning mesophase pitch having an optically anisotropic content of at least 90%, a softening point of 190° C. to 280° C. and a heating weight loss of 0.7% by weight or less at a spinning temperature to form a spun fiber, infusibilizing the spun fiber to obtain an infusible fiber and carbonizing the infusible fiber.

Abstract: The resent invention provides a carbon fiber which enables a molded article produced from a fiber-reinforced composite material using the carbon fiber to exhibit excellent flexibility and to be freed from defects such as bending. According to the method of the present invention the carbon fiber is produced by a two-stage infusibilizing process, namely carrying out a first-stage infusibilization of a pitch-based fiber, which is obtained from mesophase pitch having a softening point of 200 to 400° C. and a true density of 1.30 to 1.38 g/cm3, in a mixed gas atmosphere having a nitrogen dioxide concentration of 1 to 5% by volume and an oxygen concentration of 5 to 50% by volume, the balance being an inert gas or steam, at a temperature between 100 and 200° C. and then carrying out a second-stage infusibilization of the product of the first-stage infusibilization in a mixed gas atmosphere having a nitrogen dioxide concentration of 0.