Abstract: A method for preparing melt-blown microfibers comprising extruding fiber-forming material through the orifices of a die into a high-velocity gaseous stream where the extruded material is rapidly attenuated into fibers, directing the attenuated fibers into a first open end of a tubular chamber disposed near the die and extending in a direction parallel to the path of the attenuated fibers as they leave the die, introducing air into the tubular chamber at a velocity sufficient to maintain the fibers under tension during travel through the chamber, and collecting the fibers after they leave the tubular chamber.

Abstract: Draw breaks are reduced in the spinning and drawing of certain pigmented nylon filaments by incorporating at least 5% of polycaproamide in the melt shortly before spinning.

Abstract: A process for improving the strength of fibers from anisotropic-melt-forming polyesters involves polymerization of the polyester precursors in the presence of defined amounts of lithium chloride or acetate followed by melt-spinning the polyester into fiber and subjecting the fiber to a specified heat treatment.

Abstract: A process for producing batches of a mouldable, fibre-reinforced thermoplastic material matched to a moulding to be produced and accompanied by heating, wherein quantities of an initial product of fibres and thermoplastic material-containing binder are intermittently moved into a preheating station, and intermittently moved therefrom through a melting channel as a strand and a matched batch is separated from the strand and supplied for batch further processing.

Abstract: This invention relates toa process for manufacturing a ribbon constituted by at least one yarn impregnated with a thermoplastics polymer, wherein the ribbon is obtained by controlled sheathing of the yarn by the thermoplastics polymer, then passage of the yarn thus sheathed between two rollers crushing the yarn while the polymer is in its plastic state. This is obtained either by heating the rollers, or, preferably, by subjecting the polymer to the action of ultra-sounds during its passage between the two rollers.

Abstract: A process for the manufacture of a crimped polyester yarn obtained from a polyester partially-oriented yarn comprising fabricating a partially-oriented polyester yarn by a high-speed process, cooling the partially-oriented polyester yarn, cold drawing the cooled yarn, and subjecting the cold drawn polyester yarn to a thermal treatment under tensionless conditions or under controlled overfeed conditions.

Abstract: A process for the manufacture of microfiltration membranes from aromatic polyamides, of which the pore sizes are between 0.05 and 10 .mu.m. A copolymer of isophthalic acid and m-phenylenediamine is dissolved in a solvent mixture of dimethylacetamide and dimethylformamide in the presence of alkali or alkaline earth chlorides and polyethyleneglycol. This solution is produced without the addition of water and is subsequently poured out onto a smooth surface formed of chemically inert material with the formation of the membranes. The water that is required as the precipitation agent, is only added to the poured-out solution by means of the air humidity. The relative air humidity is increased from 30% to 100% during formation of the membranes.

Abstract: Incorporating a minor amount of a hydrogen bonding additive such as nylon 6 monomer or 2-methyl-pentamethylene adipamide monomer in a nylon 66 high RV polymer for making nylon 66 POY provides unexpected downstream advantages over homopolymer nylon 66 POY, especially in draw-texturing to make bulky yarns for use in hosiery.

Abstract: A process is disclosed for improving the handling control of a moving, wet, unitary bundle of a plurality of yarns wherein a tension is applied to the yarn between the spinneret and the feed rolls until individual yarns can be separated from the bundle and, then, the tension is removed and the separation is maintained.

Abstract: A process for making fibers of para-aramid and poly(vinyl pyrrolidone) (PVP) comprising agitating a mixture of solvent acid, para-aramid, and PVP, heating the mixture to form a solution, extruding the solution, drawing the extruded solution, passing the stretched solution through an aqueous coagulating bath to form filaments and washing the filaments.

Abstract: Methods for producing fibers of self-protonated sulfonic acid-substituted polyaniline compositions. The sulfonated polyaniline compositions have faster electronic and optical responses to electrochemical potentials comparing to its parent polyaniline, improved environmental stability, and improved solubility than the parent polymer, polyaniline.

Abstract: A network of non-porous polyethylene fibers substantially free of voids formed by preparing a network of gel spun fibers, applying pressure to the network at a temperature and pressure and for a time adequate to form a translucent film substantially free of voids.

Abstract: An improved process for manufacturing a polycrystalline alumina fiber comprising dissolving aluminum alkoxide in alcohol, adding acetylacetone, hydrolyzing with water, and polymerizing to form a polymeric alumina sol and spinning the polymeric alumina sol by using a spinning apparatus.

Abstract: Polyethylene terephthalate yarn is prepared by spinning under very high-stress conditions wherein oriented-crystalline undrawn yarns are obtained. Selection of process parameters yields a partially oriented semicrystalline undrawn yarn with a crystallinity of 16 to 24 percent and a melting point elevation of 14.degree. to 22.degree. C. which is drawn to produce the resulting unique combination of properties: (A) a terminal modulus of at least 20 g/d, (B) a dimensional stability defined by E.sub.4.5 +FS<11.5 percent, (C) a tenacity of at least 5 grams per denier, (D) a melting point elevation of 14.degree. to 22.degree. C., preferably 17.degree. to 20.degree. C., and (E) an amorphous orientation function of less than 0.75. The resulting treated tire cord unexpectedly provides high ultimate elongation and high toughness in combination with improved dimensional stability.

Abstract: A method of forming a bio-compatible vascular prosthesis comprising making a polymer material by coagulation in which the polymer, dissolved in an organic solvent, is formed into the material in a coagulant, the method being carried out at such low temperature as not substantially to degrade the polymer.

Abstract: Injected fluid plastic material directed to a predetermined side of a film section that is inserted into a mold cavity by utilizing a mold that includes a first mold part with a first mold-cavity section and a second mold part with a second mold-cavity section, a gate with a gate region, and a multitude of specific flow channels in the first mold-cavity section for directing injected plastic material away from the gate region; placing the film section in the second mold-cavity section so that the film section covers an extensive region of both the specific flow channels and the thin mold-cavity region and so that the film section does not cover a first segment of each of the specific flow channels which are closest to the gate region, but does cover a second segment of each of the specific flow channels which is a continuation the first segment of each of the specific flow channels; and injecting the fluid plastic material into the mold-cavity, so that the fluid plastic material flows away form the gate regio

Abstract: A generally hydrophobic polyester article is provided with a generally hydrophilic surface by contacting said general hydrophobic polyester with a copolymeric material while said polyester is at a temperature above its melting point. The copolymeric composition comprises a generally hydrophobic moiety and a generally hydrophilic moiety. Also disclosed is a method for imparting the hydrophilic surface to a generally hydrophobic polyester which method comprises contacting a generally hydrophobic polyester with a copolymeric material while said generally hydrophobic polyester is at a temperature above its melting point. In one preferred embodiment the generally hydrophobic polyester is contacted with said copolymeric composition immediately after said polyester has been extruded and while said polyester is undergoing die swell.

Abstract: Dyeable fibers are formed from polypropylene by blending a major portion of polypropylene with a minor portion of 1) a copolymer of nylon 6,6 and substantially equimolar amounts of hexamethylene diamine and an alkali metal salt of 5-sulfoisophthalic acid or 2) a basic reaction product of substantially equimolar amounts of N-(2-aminoethyl) piperazine and adipic acid, hexamethylene diamine and adipic acid and optionally .epsilon.-caprolactam. The blend is formed in an extruder and extruded into filaments which are quenched in air, stretched 2-4.times. (preferably at an elevated temperature) and bulked using a jet of heated turbulent fluid. The thusly bulked filaments are then dyed.

Abstract: The process for production of polyacrylonitrile hollow threads with a stable, asymmetric pore structure by a dry-wet-spinning process with glycerine-based core liquids, definite draw and after treatment conditions and a treatment with alcohols and drying.

Abstract: A process for preparing a refractory material comprises subjecting a blank of a precursor composition to pyrolysis under isostatic pressure conditions in the absence of a separate hermetically sealed envelope enveloping the blank, the precursor composition comprising a thermoformable carbon precursor component.