Abstract: Alkali resistant glass fibers and mineral wool are produced from perlite by heating perlite ores until the melt viscosity is under 15 poise and impinging a stream of the melt with a gas at from 80 to 100 psig to produce the fibers.

Abstract: An improved process for drawing a continuous length of an acrylic multifilament fibrous material is provided. Prior to drawing at an elevated temperature by continuous passage through a suitable drawing zone the surface of the fibrous material is coated with powdered graphite (e.g. colloidal graphite) via contact with a dipersion containing the graphite paticles which serve to improve the drawing properties of the same. The process is suited for the hot drawing of a continuous length of an acrylic multifilament fibrous material (e.g. a substantially untwisted tow) which is intended for subsequent thermal stabilization, and cabonization to form a carbonaceous fibrous material.

Abstract: Suitable pitch is formed into a filament continuously and upward by various means located at the bottom of a vessel containing a hot buoyant liquid. The liquid buoys up the fragile filament as it ascends the vessel from a lower region held at one temperature to an upper region where the temperature is about 450.degree.-700.degree.C. The filament emerges upward out of the liquid to move further through a still higher temperature (>900.degree.C) zone which upon leaving the previously formed pitch is a carbon filament. The liquid can be a blend of suitable molten inorganic salts or a molten inorganic oxide.

Abstract: A process for strengthening carbide fibers by removing internal stresses caused by their formation. This process is accomplished by drawing the carbide fiber under tension through a furnace. The temperature of the furnace may range from about 2050.degree. to 2300.degree.C while the fiber tensile stress may vary from about 200 to 3500 p.s.i. when using boron carbide fibers with diameters ranging from about 8 to 14 microns.

Abstract: The efficient production of pervious low density carbon fiber reinforced composite articles is made possible through the use of the present invention. A fibrous open weave tape (as described) which is capable of undergoing conversion to a carbonaceous fibrous material is continuously passed in the direction of its length through a series of heating zones to form a fibrous carbon tape (preferably of graphitic carbon) wherein an open weave construction is maintained. At least one layer of the resulting fibrous open weave carbon tape may be impregnated with a thermosetting resinous material, and subsequently cured to form a pervious composite article.The composite articles exhibit a high specific modulus and strength, and are extremely lightweight. The lightweight composite articles may be utilized as structural elements, and are particularly suited for use as a facing sheet of an acoustic sandwich liner which serves as a noise suppression function in jet engines.

Abstract: Process for producing continuous alumina multifilament yarns which comprises preparing an aqueous spinning mix containing selected alumina particles and water-soluble precursors of alumina in selected amounts, spinning filaments from the mix, forming a continuous filament package on a collapsible, refractory bobbin at a windup speed which attenuates the filaments, firing the package in a furnace at selected temperatures in either one or two steps, and then firing the yarn while backwinding it. A bobbin is obtained which is wound with strong substantially straight yarn of at least five aligned polycrystalline .alpha.-alumina continuous filaments, which yarn can be backwound from the bobbin.

Abstract: Alumina fibre is prepared by spinning a solution containing an aluminium compound and an organic polymer, removing solvent and contacting the fibre with ammonia or an amine before conversion of the fibre to alumina.

Abstract: In the production of aluminum oxide fibers comprising dry spinning an aluminum-containing solution to produce fiber and thereafter heat treating the fiber, the improvement which comprises applying to the fiber prior to heat treatment a solution of polyvinyl acetate in a solvent which is inert to the fiber. Advantageously the polyvinyl acetate is present in its solution in a concentration of about 0.1 to 10% by weight and is applied to the fiber in about 0.1 to 3 % by weight. The spinning solution may also contain SiO.sub.2 and polyethylene oxide, and the polyvinyl acetate solution may also contain di-n-butyl phthalate as a plasticizer for the polyvinyl acetate. The fiber bundles are characterized by increased strength and resistance to breaking during further processing.

Abstract: Method and apparatus for forming fibers of refractory materials. A melt volume is continuously formed on a feed rod of the material to be fiberized and a fiber drawn therefrom. The melt volume is formed by introducing the feed rod at a predetermined velocity into a heating zone. The fiber diameter is determined by the relative velocities at which the feed rod is moved and the fiber drawn, and by the fractional density of the feed rod material.

Abstract: Graphite composite, prepared by heating a material which forms a graphitizable carbon to mesophase, adding carbon fiber composite and carbonizing and graphitizing the shaped composite.

Abstract: Organic fibrous material is changed to heat-stabilized material by heating in an atmosphere, and then the heat-stabilized material is carbonized in a carbonizing furnace at a temperature of from about 800.degree.C to 1600.degree.C.When temperature at any given point in the furnace is plotted on a vertical axis and the particular location along the length of the carbonizing furnace is plotted on a horizontal axis, the slope of the resulting temperature profile above 800.degree.C either remains constant or decreases until the maximum temperature in the furnace is reached.

Abstract: A method of enhancing the tensile strength of carbon fibers of laboratory d commercial materials. Carbon fibers are immersed at ambient temperatures in liquid bromine or bromine dissolved in a solvent within a chemical resistant container for a period of time, the bromine is then removed by flushing with an inert gas. The removed bromine may be recovered and reused by condensing the vapor; small traces of bromine may remain within the fiber. It has been found that the bromine treatment enhances the tensile strength of the treated fiber.