Abstract: High modulus, high tenacity fibers of poly-p-phenylene terephthalamide (PPD-T) are manufactured comprising a fiber heat treating process for increasing the inherent viscosity and the crystallinity index of the PPD-T. Never-dried fibers swollen with water of controlled acidity are heated beyond dryness in an atmoshphere having a flow of greater than Reynolds Number 10,000 throughout the duration of the heating.

Abstract: A process for the production of high-quality carpet yarn from PBT having an intrinsic viscosity of 0.9 to 1.2 comprising an integrated spinning-draw texturing process, employing a transport speed to the texturing unit of at least 1,800 m/min.

Abstract: A process for preparing aromatic polyamide fibers 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, and the liquid crystalline prepolymer dope is subjected to a molecular orientating polymerization in a polymerization accelerating-precipitation solvent to provide aromatic polyamide fibers free of a crystal defect layer perpendicular to the fiber axis and having high strength and high degree of molecular orientation.

Abstract: A process for forming high free volume, asymmetric gas separation membranes having graded density skins and macrovoid-free morphology from a solvent system comprising a Lewis acid, Lewis base, and a Lewis acid:base complex which dissolve hydrophobic polymers. The dopes have high total solids, high viscosity and low coagulation (g) values which enhance rapid gelation without the formation of macrovoids and which minimize densification. The dope solvent system complexes are readily disassociated by the coagulation medium and the component molecules are miscible in the medium which provides for rapid desolvation of the formed membrane thus providing a membrane having low residual solvent retention.

Abstract: Aromatic polyester fibers having high strength and high modulus of elasticity can be obtained stably for a long period of time by melt spinning by using a screw type extruder having a screw which has a compression ratio of 2.5 to 4.0 and thereby inhibiting entrapment in the resultant molten polyester of gases present in or on prowders, granules or pellets being melted, and by back pressure of the molten polyester sending gas generated by decomposition of the molten polyester to a back portion of the extruder, and then extruding and melt spinning the molten polyester at a temperature of 280.degree. C. to 420.degree. C.

Abstract: A shaped and drawn aromatic imide polymer article, for example, a film or filament, is produced by shaping an aromatic polyamic acid solution containing an imidizing agent in a polar organic solvent while simultaneously imidizing a portion of the aromatic polyamic acid to an extent such that the resultant self-supporting precursory article contains 20% to 87% by weight of a volatile substance and has a tensile strength of at least 1.5 kg/mm.sup.2 and an ultimate elongation of at least 30%, by drawing the precursory article at a draw ratio of 1.3 or more and by heat-treating the drawn article at a temperature of 150.degree. C. or more.

Abstract: Novel polysiloxazanes comprising [(SiH.sub.2).sub.n NH] and [(SiH.sub.2).sub.m O] as the main repeating units are provided. The polysiloxazanes are produced by reacting a dihalosilane or an adduct thereof with a Lewis base, with ammonia and water vapor or oxygen. From the polysiloxazane, novel silicon oxynitride shapes can be produced and the silicon oxynitride shapes are essentially composed of silicon, nitride (5 mol % or more) and oxygen (5 mol % or more).

Abstract: A process for manufacturing an organic silazane polymer which comprises reacting ammonia with a mixture of at least one compound selected from the group consisting of organic silicon compounds of the following formulae (I) and (II) ##STR1## and at least one compound selected from the group consisting of organic silicon compounds of the following formula (III) ##STR2## in which R represents hydrogen, chlorine, bromine, methyl radical, ethyl radical, phenyl radical or vinyl radical, R.sub.1 represents hydrogen or methyl radical, R.sub.2 represents hydrogen, methyl radical, ethyl radical, phenyl radical or vinyl radical and X represents chlorine or bromine; to obtain an ammonolysis product. The ammonolysis product is polymerized in the presence of a basic catalyst capable of deprotonation to obtain an organic silazane polymer. The silazane polymer may be further melted, shaped and infusibilized. The thus infusibilized product is finally sintered to obtain a ceramic material.

Abstract: A method for manufacturing carbon fiber strand from an acrylic polymer by steps of (a) wet spinning, (b) washing with water to obtain gelled fiber strand and (c) drying, wherein during the drying step the gelled fiber strand is shrunk by about 5 to 15% when the water of the gelled fiber strand is within a range of from about 100 to 20% by weight based on the weight of the dry fiber strand. An acrylic fiber strand without coalescence or entangling of filaments can consistently be obtained, from which carbon fibers with high quality and substantially no coalescence can be produced.

Abstract: High strength polyester multifilament yarn of improved dimensional stability, which has the proper combination of an intrinsic viscosity of at least 0.90, relatively low work loss and a high degree of toughness, is incorporated as tire cord into a rubber tire for reinforcement to provide an important improvement in fatigue life and retained fatigue strength. The continuous melt-spin process comprises the steps of feeding prepolymer to a first finisher vessel to achieve at least 0.4 intrinsic viscosity transferring polymer to a second finisher vessel for a period sufficient to achieve an intrinsic viscosity of at least 0.95, and supplying this polymer to an extrusion spinnerette.

Abstract: An injection molding method in which an insert is inserted into a metal mold assembly in advance of molten material by providing a guide member having an aperture in which the insert is inserted, the insert and aperture having relative dimensions such that the insert is forcibly retained in the aperture and to properly locate the insert for injection molding and thereby prevent displacement of the insert during injection molding.

Abstract: In a process for producing an aromatic polyester fiber by heat-treating a fiber obtained by melt-spinning an aromatic polyester exhibiting anisotropy in its molten state, an aromatic polyester fiber having high strength and high modulus of elasticity can be produced with suppressed fusion between single filaments during the heat treatment by (a) subjecting the fiber obtained by melt spinning to heat treatment in an organic liquid heating medium or (b) adhering to the fiber obtained by melt spinning at least one member selected from the group consisting of suspensions having a concentration of 0.05 to 20% by weight of organic polymer powders having a melting point or a softening temperature higher than the heat treatment temperature, and suspensions having a concentration of 0.1 to 20% by weight of barium sulfate powder or barium titanate powder, and then subjecting the resulting fiber to heat treatment.

Abstract: A high speed process for producing polyamide filaments utilizing one or more melt additives selected from the group consisting of water, alcohols, and organic acids to form a homogeneous polyamide-additive mixture so that upon extrusion of the mixture the polyamide has a relative viscosity in the range of from about 2.0 to about 3.0, melt-extruding the mixture to form filaments, quenching and drawing the filaments, and taking up the filaments at a speed greater than 4000 mpm. The process improves package build, yarn quality, and yarn processing conditions, and enables low elongations, high tenacity, and higher production speeds.

Abstract: Long lengths of a heat-shrinkable sleeve for use in splicing electrical cables and the like are manufactured by providing an elongated impermeable core having a smooth outer surface, extruding an elongated sleeve around and in contact with the core, the sleeve having a smooth inner surface conforming to the outer surface of the core, and effecting an initial expansion of a portion of the sleeve to a larger diameter in an expansion zone so that the sleeve separates from the core and leaves a space between the sleeve and core. A fluid is introduced into the space under pressure via a fitting at the downstream end of the sleeve while continuously advancing the sleeve and core through the expansion zone. To begin the process, a permeable core is used, and the sleeve is extruded around and in contact with the permeable core.

Abstract: A thermoplastic polymer yarn is spun into a spinning tube charged with a pressurized gas of more than 1 kg/cm.sup.2 G and withdrawn through a yarn exit provided with a unique sealing means which substantially prevents the charged gas from leakage but allows passage of the yarn out from the spinning tube. The resultant yarn has a high molecular orientation due to the improved quenching effect and the increase of resistance against yarn travelling of the charged gas.

Abstract: Process for molding and vulcanizing tires and other rubber articles, in which in a press with the aid of a bladder negative shapes are pressed into the tire blank under high pressure and vulcanization is performed, the surface of the bladder having applied thereon a solvent which swells the surface, the swollen bladder being provided with a cross-linked, hardened, tightly adhering, elastic release agent film bonded to the bladder by chemical interactions before carrying out molding and vulcanization to prevent sticking of the molded and vulcanized tire to the bladder, the film comprising more than one thin coating each of which is produced by coating the bladder with an organic solvent solution comprising a mixture of a silicon release agent and a moisture or heat curable silicone rubber and curing the coated mixture through exposure to moisture or heat, and conducting at least 300 molding and vulcanizing cycles without recoating the bladder with the release agent film.

Abstract: Water absorbent, water insoluble, cross linked polymer fibre or film can be made by dry extrusion of a solution of a substantially linear polymer formed from a water soluble blend of monoethylenically unsaturated monomers comprising a plasticizing monomer, evaporating the solvent and forming polymeric fibre or film plasticized by an external plasticizer, stretching the fibre or film while the external plasticizer remains in the fibre or film, and then cross linking the polymer.

Abstract: A method for manufacture of a sealing ring with a flanged sealing lip having hydrodynamically acting return transport properties in which a sealing lip is first generated by extrusion of a plastically deformable material through a ring nozzle having rotating inner and outer surfaces which are rotated relative to each other to impart a helical motion to the extruded material; the hydrodynamically acting return transport properties being a microscopically fine pleating of the surface of the extruded hollow cylinder. The extruded cylinder is then solidified and cut to a predetermined length. The cylinder is then widened in the radial direction at its front end by an assembly tool which shapes the cylinder into a trumpet-shaped sealing ring with a flanged sealing lip.

Abstract: Machined steel blocks 1 and 2 have ridges 20 facing valleys in the opposite block. Polypropylene tape 3 to be heat-treated has sliding contact transversely over each ridge on each block. The blocks are heated by heaters 4. The gap between the blocks is adjustable to suit the material being processed. The gap is large enough so that the tape passing between the blocks is not constrained to deflect from coplanarity by more than its own thickness.

Abstract: A textile sheet structure which is irreversibly highly deformable is prepared by weaving or knitting a yarn which has a degree of elasticity under a load of 5 cN/tex of less than 50% and which consists at least in part of partially oriented, undrawn synthetic filaments which have birefringence values above 20.times.10.sup.-3, elongations at break between 70 and 200% and flow stresses of at least 6 cN/tex, which have been produced by high-speed spinning and are then subjected to a heat treatment under stress at temperatures between 100.degree. and 180.degree. C.