Abstract: A process for preparing an asymmetrical macroporous membrane from a polymer solution comprised as the dissolved portion fraction a polymeric mixture comprised of about 5-70% by weight of polyvinylpyrrolidone having a molecular weight of .gtoreq.100,000 Dalton and about 95-30% by weight of a polymer selected from the group consisting of polysulfone, a polyether sulfone, and an aromatic or araliphatic polyamide, said weight being relative to the total weight of the dissolved polymeric fraction, by action of a coagulating liquid, wherein the coagulation is effected under conditions such that skin formation, asymmetrical port formation and retention of the polyvinylpyrrolidone are achieved, recovering the asymmetrical macroporous membrane comprising the polymeric mixture.

Abstract: A process for the preparation of fibers of syndiotatic polystyrene, or a mixture of isotactic polystyrene and syndiotactic polystyrene which comprises:A. heating syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene, to a temperature between its crystal melting point and the temperature at which the polystyrene undergoes degradation, wherein the polystyrene has sufficient viscosity to be extruded:B. extruding the polystyrene through an orifice to form a fiber at elevated temperature;C. quenching the fiber by passing the fiber through one or more zones under conditions such that the fiber solidifies; andD. cooling the fiber to ambient temperature.

Abstract: A process for making oriented, shaped articles of lyotropic polysaccharide/thermally-consolidatable polymer blends by orienting spinnable dopes containing fiber-forming polymers being at least about 55% and less than about 80% lyotropic polysaccharide and at least about 20 percent and less than about 45% thermally-consolidatable polymer and removing the solvent.

Abstract: The present invention relates to the production of high tensile strength, solvent-spun cellulose fiber which is stable in alkaline solutions. More particularly, the invention relates to a process in which cellulose is solubilized in a zinc chloride solution then extruded into a coagulation medium in which the cellulose fibers form. The fibers are removed from the coagulation medium, treated to remove the coagulation medium, stretched and recrystallized in water, thus forming the high tensile strength, solvent-spun cellulose fibers.

Abstract: A process for producing a polyhalogenated microporous film having a very narrow pore size distribution and good temperature and chemical resistance. The process involves blending a polyhalogenated copolymer having a very small particle size with a binder polymer utilizing a solvent which is a nonsolvent for the polyhalogenated copolymer but a solvent for the binder polymer, forming a film from the blend, drying the film, heating the film to a temperature at or above the melting point of the polyhalogenated copolymer and under conditions such that the microparticulate particles at their points of mutual contact will neck together to form a relatively continuous matrix and extracting the binder polymer from the film utilizing a solvent for the binder particle to form a microporous film.

Abstract: Preceramic fibers are produced by dissolving a solid organosilicon preceramic polymer in a solvent to form a spinning solution containing at least seventy percent polymer solids, dry spinning and extracting solvent in the presence of a non-oxidizing gas at a temperature and pressure sufficient to vaporize solvent from the fiber, and at least one curing agent being added to the non-oxidizing gas or spinning solution, or both, to induce on-line curing of the fiber or to aid in subsequent curing of the fiber or both. The preceramic fibers are thereafter pyrolyzed to ceramic form.

Abstract: A fiber or filament of a swellable polymer of high tensile strength is made by spinning a polymeric raw material which is produced by agitating a suspension of solid particles of an acrylonitrile polymer in dilute sulfuric acid having an acid concentration between 40 to 50 percent by weight until the polymer is hydrolyzed to an extent that it contains from 10 to 30 percent by weight of carboxyl groups such that sticking of individual particles of the polymer to one another is avoided.

Abstract: A process of making carbon-bonded refractory shapes by preparing a mix of refractory materials, pitch or tar and a binder resin, molding the mix into shapes and hardening the shapes. A starting mix is used which, based on the added quantity by weight of pitch or tar, contains 1 to 10 weight % of hollow fibers. The refractory shapes have the advantage that they exhibit less cracking, and hardly any, or even no, breaking occurs during their fabrication.

Abstract: A method of spinning filaments from a melt which comprises flowing said melt through openings in a nozzle plate to form a stream of said filaments, directing a coolant radially outwardly from the center of said stream through a porous wall of a dispersing head provided with a downstream baffle adjusted to partially reduce the inside pressures of the coolant adjacent to the baffle to a value lower than the outside pressure, the resistance of said coolant caused by the wall porosity satisfying the relationship1.43.times.10.sup.6 m+2222 m.sup.2 =p=-96.96 m+20202 m.sup.2wherein m is the rate of flow of said coolant across the area of said porous wall in kg/h-cm.sup.2, and p is the pressure drop in Pa.

Abstract: A single-piece foam pattern for use in the lost foam casting of a ported cylinder sleeve is formed in a molding tool having a pair of displaceable elements and a removable center core. Ports, of preselected size, shape and location, are defined by movable cores which are extended into position between the displaceable elements and the center core. Following introduction of a molding material, the movable cores are retracted after which the mold elements and center core are separated and the foam pattern is removed.

Abstract: A process for preparing high modulus, high tenacity fibers of aromatic polyamide wherein a first constant tension within 40-95% of the fiber breaking load is applied to washed fibers at a temperature of less than 50.degree. C. for a duration of greater than 5 seconds, and drying the fibers at a second constant tension which is from 10-100% of the first constant tension and at a temperature of more than the temperature of the first constant tension and less than 350.degree. C. until the fibers have a moisture content of about 2 to 10%.

Abstract: A method for controlling a quench fluid velocity delivered to a quench zone in a polymer melt spinning process wherein the quench fluid velocity is measured by a velocity detector, compared to a desired quench air velocity and a damper valve mechanism is adjusted in a quench fluid duct so that the desired quench fluid velocity is obtained.

Abstract: A method of extracting a material from a continuous running length of fiber comprising continuously moving the fiber through a conduit while simultaneously flowing a solvent for the material through the conduit with the conduit having a length and cross sectional area sufficient to facilitate extraction of the desired amount of the material. The flow is countercurrent to the movement of the fiber.

Abstract: A process for the preparation of a membrane comprising bisphenol-based polycabonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is Cl or Br, and the membrane prepared by such process.

Abstract: A method of producing a polyester filament which has a superior combination of tensile, dyeability and shrinkage properties. The method comprises forming a polyester-polyethylene glycol copolymer from a mixture consisting essentially of a terephthalic acid or dimethyl terephthalate, ethylene glycol, and polyethylene glycol, with the polyethylene glycol having an average molecular weight of between about 200 and 1500 grams per mole and being added in an amount sufficient to produce a polyester-polyethylene glycol copolymer in which the polyethylene glycol is present in an amount of between about 1.0 and 4 percent by weight of the copolymer formed; forming filament from the copolymer drawing the copolymer filament; and heat setting the drawn filament.

Abstract: A composite chromatographic sheet-like article is prepared by the steps comprising blending one or more non-swellable sorptive hydrophobic particulate materials in the presence of an amount of polar organic masking agent sufficient to allow rapid wetting of the surface of the particulate and in the presence of sufficient lubricant water to exceed the sorptive capacity of the particulate, provided that the volume ratio of water to masking agent does not exceed 3:1, adding with stirring an aqueous emulsion of polytetrafluoroethylene so that the resulting mass has a dough-like consistency, mixing the mass in an intensive mixer at a temperature between 50 C. and 100 C. for a time sufficient to cause fibrillation of the polytetrafluoroethylene particles, biaxially calendering the mass, while maintaining water at a level near the absorptive capacity of the particulate, between a gap in the calendering rolls maintained at about 50 C. to about 100 C.

Abstract: A method for applying a uniform sealant coating over the portion of a fastener exposed above a panel includes applying a sealant retaining shell over the exposed portion of the fastener to define a closed volume between the shell, fastener and panel. The shell has an aperture, removed from the mouth of the shell, for receiving sealant therethrough. An injection nozzle receiving structure for receiving a sealant injector nozzle therein is provided adjacent and substantially aligned with the aperture. Sealant is injected into the shell through the injection nozzle receiving structure and through the aperture therein to fill the area between the fastener and the shell. A pressure is selected for injecting the sealant such that injection is stopped when the shell is filled. The sealant is allowed to cure and the retaining shell is removed.

Abstract: A process for preparing aromatic polyamide film wherein an aromatic diamine and an aromatic diacidchloride are dissolved in an amide polymerization solvent containing an inorganic salt, a partial polymerization is effected at a low temperature to form an optically anisotropic liquid crystalline prepolymer dope, continuously extruding through a film die under a draw ratio or subjecting to a shear and contacting the prepolymer with a second solvent which is a polymerization accelerating-precipitation solvent to obtain an aromatic polyamide film free of crystal defect layer perpendicular to the film axis and having high strength and a high degree of molecular orientation.

Abstract: A yarn comprising polyester fibers having an improved balance of properties (tenacity and boiling water shrinkage) is produced within predetermined limits. The polyester yarn is prepared by cold drawing a partially oriented feeder yarn, partially annealing the drawn yarn, and subsequently annealing the partially annealed cold drawn yarn at controlled tensions.

Abstract: Isotropic microporous polysulfone membranes can be prepared by using a particular combination of casting solution and precipitation solution formulations, and casting conditions. Both hollow fiber and flat membranes can be prepared in this manner. The membranes are skinless and are characterized by uniform porosity throughout the membrane.