Abstract: An ultra-high-tenacity multifilament fiber of polyvinyl alcohol having a degree of polymerization of at least 1500, said filament having a tensile strength of at least 12 g/d and an initial modulus greater than 280 g/d, which is produced by a process for producing an ultra-high-tenacity polyvinyl alcohol fiber which comprises the steps of dissolving polyvinyl alcohol having a degree of polymerization of at least 1500 in a solvent, dry-spinning the resulting polymer solution through a spinneret into an environment of air or inert gas, introducing the dry-spun filaments into a coagulating bath, and drawing the coagulated filaments at a total effective draw ratio of at least 20 times.

Abstract: The conventional spandex spinneret has two rings of equally spaced grouped orifices, each filament being formed by coalescence of the extrudate from the grouped orifices. A spandex spinneret having the holes of the orifices of each group of the outer ring of groups more closely spaced than those of the inner ring of groups has eliminated the power differences between inner and outer threadlines. The closer spacing within each group of the outer ring of groups also increases the spacing between groups, thereby reducing filament migration.

Abstract: Solutions of ultrahigh molecular weight polymers such as polyethylene in a relatively non-volatile solvent are extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length. The first gels are extracted with a volatile solvent to form a second gel and the second gel is dried to form a low porosity xerogel. The first gel, second gel or xerogel, or a combination, are stretched. Among the products obtainable are polyethylene fibers of greater than 30 or even 40 g/denier tenacity and of modulus greater than 1000 or even 1600 or 2000 g/denier.

Abstract: Solutions of ultrahigh molecular weight polymers such as polyethylene in a relatively nonvolatile solvent are extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length. The first gels are extracted with a volatile solvent to form a second gel and the second gel is dried to form a low porosity xerogel. The first gel, second gel or xerogel, or a combination, are stretched. Among the products obtainable are polyethylene fibers of greater than 30 or even 40 g/denier tenacity and of modulus greater than 1000 or even 1600 or 2000 g/denier.

Abstract: A laminate comprising an insoluble, intractable relatively thick layer of a polyimide bonded tightly onto a metallic substrate without the necessity for an intermediate adhesive bonding layer and a process for preparing such by directly extruding a polyamic acid polyimide-precursor onto said substrate and converting said polyamic acid to the polyimide in a single pass in at least two heating stages.

Abstract: A membrane cast in the form of either a hollow filament or a flat film formed of a polybenzimidazole polymer is subjected to an annealing process by contacting the membrane with a non-aqueous annealing medium comprised of a solvent for the polymer and a non-solvent for the polymer. Such an annealing step can advantageously occur at an annealing temperature below about 125.degree. C. (e.g., below 100.degree. C.) These polybenzimidazole membranes find particular utility in reverse osmosis desalination processes. The annealing step of the present invention improves the mechanical and separative properties of the membrane.

Abstract: A heat-shrinkable polyimide film which comprises a polyimide film prepared by converting at least about 50% by weight of polyamide acid obtained by reacting a biphenyltetracarboxylic acid dianhydride represented by the general formula ##STR1## with an aromatic diamine into polyimide, and stretched in at least one direction to provide heat-shrinkability, and a process for producing the film.

Abstract: A novel process for the preparation of a pharmaceutical preparation in the form of an polyacrylate film for long-term transdermal administration of systemic pharmaceuticals comprising forming a homogeneous solution of an effective amount of a systemically acting pharmaceutical and a freeze-dried latex of a polyacrylate copolymer of methyl and/or ethyl esters of acrylic acid and methacrylic acid formed by emulsion polymerization and having an average molecular weight of about 800,000 in at least one organic solvent, forming a thin layer of the said solution and drying the layer to form a polyacrylate film and the film product produced by the said process.

Abstract: Metal coated with a polymer film having a thickness between 10 and 500 .mu.m. The film is a terpolymer comprising 88 to 98.7 mole % of units derived from ethylene, from 1 to 10 mol % of units derived from an alkyl (meth)-acrylate, and from 0.3 to 3 mol % of units derived from maleic anhydride, and optionally may contain up to 5 mol % of units derived from a fourth monomer selected from .alpha.-olefins having from 3 to 8 carbon atoms, monoalkyl maleates and dialkyl maleates in which the alkyl groups have from 1 to 6 carbon atoms, vinyl acetate, and carbon monoxide. The terpolymer film has a melt index of between 2 and 10 dg/minute. The metal substrate is coated with the terpolymer film at a temperature between 140.degree. C. and 300.degree. C., the speed of travel of the metal substrate being between 40 to 400 meters per minute.

Abstract: A casting solution of two nylons in formic acid, e.g., high molecular weight extrusion grade Nylon 66 homopolymer [.eta.] about 2 or higher, and nylon multipolymer 66, 610, 6 as a strengthening polymer and gelation promoter, when cast by either the dry or wet phase inversion processes, results in highly unexpected membranes of superior strength, flexibility, and uniformity, suitable for use in microfiltration and ultrafiltration.

Abstract: An improved process for the preparation of polymer filaments having a high tensile strength and modulus by spinning a solution of high-molecular weight polymer and thereafter stretching the filament thus formed. A solution of an ethylene polymer or copolymer, containing at least 80 percent by weight solvent, is spun at a temperature above the gel point of the solution. The ethylene polymer or copolymer contains at most about 5 percent by weight of an alkene having 3 to 8 carbon atoms, has a weight-average molecular weight Mw higher than 4.times.10.sup.5 kg/kmole, and has a weight/number average molecular weight ratio Mw/Mn lower than 5. The spun polymer solution is thereafter cooled to a temperature below its gel point to form a gel filament, which gel filament is thereafter stretched to form a polymer filament having a tensile strength of at least about 1.5 GPa at room temperature.

Abstract: In order to conduct thoroughly pre-mixed hot gas into a ring spinning nozzle by a rotational flow in such a manner that sufficient quantities of hot gas are available for drying the filaments situated on the inside without causing backflow and without any significant movement of the filaments by turbulence, an annular chamber with tangential inlet is placed around the ring spinning nozzle. The internal wall of the chamber is separated from a circular chamber by equalizers in its upper region while on its underside it is separated from the spinning chamber by equalizers and metal gauzes at the level of the lower edge of the spinning nozzle. The circular chamber is also separated on its underside from the spinning chamber by equalizers and metal gauzes.

Abstract: The invention relates to the preparation of filaments with a high tensile strength and a high modulus and to the filaments thus prepared. A solution of a linear polyethylene with a weight-average molecular weight of at least 4.times.10.sup.5 is spun and the filaments, from which the solvent may have been removed in whole or in part, are drawn using a draw ratio of at least (12.times.10.sup.6 /M.sub.w)+1. The filaments are drawn at a temperature such that the modulus is at least 20 GPa.The invention allows filaments to be prepared at high drawing rates, of 0.5 sec.sup.-1 or more, with a modulus of at least 20 GPa and a tensile strength of at least 1 GPa.

Abstract: Solutions of ultrahigh molecular weight polymers such as polyethylene in a relatively non-volatile solvent are extruded through an aperture at constant concentration through the aperture and cooled to form a first gel of indefinite length. The first gels are extracted with a volatile solvent to form a second gel and the second gel is dried to form a low porosity xerogel. The first gel, second gel or xerogel, or a combination, are stretched. Among the products obtainable are polyethylene fibers of greater than 30 or even 40 g/denier tenacity and of modulus greater than 1000 or even 1600 or 2000 g/denier.

Abstract: Process for the production of filaments of polyethylene with high modulus and tensile strength, comprising spinning a filler containing solution of a linear polyethylene with a weight-average molecular weight (M.sub.w) of at least 400,000 to form filled filaments and then stretching the filaments.

Abstract: In conventional dry-spinning processes forming a hollow bundle of filaments, a heated inert gas is introduced to evaporate spinning solvent from the filaments, and a vacuum may be applied in the center of the bundle near the face of the spinneret to assist in drawing the heated inert gas through the filament bundle. A Coanda-flow entrainment device in the center of the bundle adjacent the spinneret face uses a small inlet gas flow directed along a Coanda surface. The device entrains gas, pulling it through the filament bundle and then directing it downward. This entrained flow can supplement or supplant the vacuum-induced flow through the filaments.

Abstract: Aromatic polyimide fibers having an enhanced mechanical strength are produced by a process comprising the steps of: preparing a spinning dope solution of at least one aromatic polyimide having 90 molar % or more of a recurring unit of the formula (I): ##STR1## wherein R is a divalent aromatic radical, in a phenolic solvent; converting the dope solution into at least one filamentary stream thereof; solidifying the filamentary dope solution stream by removing the solvent therefrom to provide at least one undrawn filament, and; drawing the undrawn filament at a temperature of 20.degree. to 600.degree. C. at a draw ratio of 1.5 to 5.0.

Abstract: A dispersion is provided for incorporation with a synthetic fiber-forming polymer. The dispersion comprises a polymer additive, such as titanium dioxide, and a glyceride which is non-resin forming when exposed to certain temperatures and pressures for specified time periods and which has an average molecular weight of between about 600 and 2400.

Abstract: An improved process for spinning a composition comprising halogenated aromatic polyesters and an oxide of antimony is disclosed. The process comprises spinning the composition through a spinneret having one or more holes which have a diameter of from about 60 to about 200 microns.

Abstract: Solvent resistant halogenated aromatic polyester fibers are prepared by heat treating the fibers at substantially constant length at a temperature of from about 270.degree. to about 295.degree. C. for from about 5 to about 60 minutes. The heat treated fibers have improved solvent resistance in that they are capable of withstanding 5 to 20 minute immersions in the commercial dry cleaning solvent perchloroethylene which is at a temperature of from about 60.degree. to about 70.degree. C.

Abstract: A process for making polymer filaments which have a high tensile strength and a high modulus by stretching a polymer filament which contains an appreciable amount of polymer solvent at a temperature between the swelling point and the melting point of the polymer.

Abstract: Spandex fiber made from a segmented polyurethane polymer is provided with improved resistance to chlorine-induced degradation, by the inclusion of finely divided zinc oxide particles having a purity of at least 99.4% dispersed in the fiber.

Abstract: The present invention provides an improved process for extruding liquid crystal polymer. The process comprises the steps of providing a fluid stream of liquid crystal polymer wherein the stream has a flow pattern comprising substantial shear flow; converting the flow of the fluid stream of liquid crystal polymer to a substantially elongational flow in the substantial absence of shear flow; and extruding the fluid stream of liquid crystal polymer to form a shaped article having the polymer molecules oriented substantially parallel to the flow direction. The resulting articles are self-reinforcing, having mechanical properties superior to conventional extruded liquid crystal polymer articles and comparable to those of articles formed from fiber-reinforced isotropic polymeric materials.

Abstract: A self-crimping, melt-spun acrylonitrile polymer fiber comprising as the continuous fiber matrix a first polymer comprising from about 80 to about 99 weight percent acrylonitrile and from about 1 to about 20 weight percent of one or more monomers copolymerizable with acrylonitrile and heterogeneously dispersed within said fiber matrix a second polymer incompatible with said first polymer.

Abstract: A single phase fusion melt of nylon 4 and water when extruded through a spinneret to form a filament which is stretched provided a fiber of good physical properties without deterioration of the fiber-forming polymer.

Abstract: Extruding a homogeneous single phase fusion melt of a poly(polymethylene phthalamide) and water through a spinneret to form filaments and stretching the resulting filaments provides fiber of desirable physical properties without significant lowering of the molecular weight of the polymer forming the fiber.

Abstract: Dry-spun hydrophilic core-jacket filaments and fibres of polycarbonates having a porosity and a water retention capacity of at least 10%, a mercury density of less than 1.0 g/cc, a strength of at least 1.5 cN/dtex and a second order transition temperature of at least 125.degree. C. and a method for producing said filament and fibres by a dry-spinning process, wherein, immediately on leaving the spinnerette but before solidifying, the filaments are brought into contact with steam.

Abstract: The present invention relates to an improved process for forming fibers for fabrics from neutralized sulfonated thermoplastic polymers, and novel ionic polymer fiber compositions derived therefrom, wherein the neutralized sulfonated thermoplastic polymer is dissolved in a solvent, preferably a mixed solvent, consisting of a backbone solvent and a polar cosolvent and spun into fibers. The neutralized sulfonated thermoplastic polymer has about 10 to about 100 meq. SO.sub.3 H per 100 grams of sulfonated thermoplastic polymer, of which at least 95% is neutralized with a cation being selected from the group consisting essentially of antimony, iron, lead, aluminum, or Groups I-A, II-A, I-B or II-B of the Periodic Table of Elements and mixture thereof.

Abstract: The invention relates to a process for the production of hygroscopic filaments or fibers by dry-spinning a polymer solution wherein immediately they issue from the spinning jet or at the latest at a time when their solidification is still not complete, the filaments are brought into contact with water-vapour or with the vapour of another liquid which coagulates filaments.

Abstract: Amide-imide polymers formable in deep section and prepared by the condensation reaction of at least one of a diacid halide or a polyanhydride or equivalent, and a diamine containing at least one imide linkage. Soluble amide-imide polymers having the general formula: ##STR1## where n is an integer greater than 10 and preferably greater than 20.

Abstract: A process for the production of high molecular weight, fiber- and film-trimming polyterephthaloyl oxalamidrazone and polydiphenylether-4,4'-dicarboxylic acid oxalamidrazone where a solution of pure terephtaloyl chloride or diphenyl-ether-4,4'-dicarboxylic acid dichloride in an inert solvent free from amines and water is slowly added, at a temperature between 10.degree. C. and 35.degree. C., to a solution of pure oxalic acid bisamidrazone in dimethyl acetamide and/or N-methyl pyrrolidone, free from amines and water, containing 4 to 6 percent by weight of anhydrous lithium chloride, the total quantity of the solvents used amounting to 1.25 to 3.30 liters per mole of oxalic acid bisamidrazone.

Abstract: The invention relates to hydrophilic fibers and filaments with good coloring response to dyes from filament-forming hydrophobic synthetic polymers having a sheath-core structure with a highly microporous core and a substantially compact sheath and having a water retention capacity of at least 10% wherein the pores in the core have an average pore diameter measured in the direction of the cross-section of the fiber, of at most 4000 A. The invention relates also to a process for the production of those filaments and fibers according to a dry-spinning process wherein a spinning solution is spun below the boiling point of the spinning solvent used.

Abstract: A method of preparing shaped polypyrrolidone articles having a high degree of tensile strength comprising forming said articles from solutions of polypyrrolidone in hydrous formic acid and drawing said articles while impregnated with said hydrous formic acid. The invention also includes the step of enhancing the tenacity of shaped polypyrrolidone articles by impregnation thereof with hydrous formic acid and drawing said impregnated articles.

Abstract: The invention relates to a process for the production of hydrophilic filaments and fibers which comprises wet- or dry-spinning a fibre-forming synthetic polymer from a spinning solvent containing from 5 to 50% of a substance which has a higher melting or boiling point than the spinning solvent which is miscible with the spinning solvent and with a liquid suitable for use as a washing liquid and which is a non-solvent for the polymer to be spun and from 0,1 to 20% by weight of at least one substance which decomposes into a gas under heating.

Abstract: The stability of a flash fibrillation process for converting thermoplastics materials into fibrils by flash extruding a hot pressurized dispersion of thermoplastics material in liquid through an orifice is improved by inserting a pressure-responsive valve in the orifice which ensures the dispersion is at a specified minimum pressure before it is extruded through the orifice. The minimum pressure should be sufficient to ensure the liquid does not volatilize prior to its extrusion through the outlet.

Abstract: A process is disclosed for producing plexifilament strands from an organic, synthetic substantially water-insoluble polymer having a selected melting point, by flash-extruding a dispersion of the polymer in water under specified conditions. The plexifilament strands produced are useful in preparing fabrics.

Abstract: Anisotropic dopes having a polymer content of at least about 20% by weight of the dope are provided. The dope may be spun into fibers, extruded as films or utilized as a fracturing agent in subterranean formations. The preparation of the dope involves dissolving a polymer selected from the group consisting of polyacryloyloxybenzoic acid, polymethacryloyloxybenzoic acid, polyacryloylaminobenzoic acid, polymethacryloylaminobenzoic acid, and mixtures thereof in an aqueous solution containing a compound selected from the group consisting of Group I metal compounds and compounds containing a protonated amine group.

Abstract: A flame-retardant fiber is made comprising 20 - 95% by weight of amino resin condensate of an amino compound and formaldehyde in which the amino compound may be a melamine, combined melamine and guanamine, combined melamine and urea, combined melamine, guanamine and urea, and benzoguanamine and/or urea, and in which the chemical bond linking the polymer chain is for the most part methylene linkage and 80 - 5% by weight of polyvinylalcohol, the resulting fiber being cured when necessary and having a tensile strength of at least 1.0 g/d., and having a break elongation of at least 5%.

Abstract: Pharmaceutical composition unit dosage forms adapted for enteral or topical administration are described, comprising a safe and effective amount of a pharmaceutically active medicament compound dissolved or uniformly dispersed in a flexible, water-soluble film carrier therefor. Admixtures of medicament and carrier are drawn into a film, which can be cut to desired unit dosage content.

Abstract: Certain halogenated aromatic polyester fibers having reduced spin-line static generation when prepared via dry-spinning from a methylene chloride containing solution are provided by admixing an esterified hindered phenol prior to dry-spinning. A preferred esterified hindered phenol which may be utilized to reduce spin-line static is tetrakis[methylene 3-(3',5'-di-t-butyl-4-hydroxyphenyl) propionate] methane.

Abstract: A method of preparing a porous sheet product which comprises the step of introducing a spinning liquid comprising an organic fibre forming polymeric material into an electric field whereby fibres are drawn from the liquid to an electrode and collecting the fibres so produced upon the electrode. PTFE and other fluorinated polymer mats produced by the electrostatic process are useful as electrolytic cell diaphragms, battery separators etc.

Abstract: Polypyrrolidone solutions having a bulk viscosity of 100-10,000 poises, and containing a solvent such as formic acid and a volatile diluent such as methylene chloride, are spun into filaments by extrusion through a spinneret. The solution contains, for example, about 5-40 weight percent of polypyrrolidone, about 30-90 weight percent of formic acid and about 5-60 weight percent of methylene chloride.

Abstract: An improved process for preparing wholly aromatic polyamide fibers of high performance charcteristics is provided. The process includes the steps of providing a spinning solution of a wholly aromatic polyamide, the polyamide having a sulfur content as sulfonic acid and/or sulfonate groups attached to the aromatic nuclei of at least 0.5 percent by weight based on the weight of the polyamide; spinning the spinning solution of the wholly aromatic polyamide to produce an as-spun fiber having an inherent viscosity of at least 1.0; and heat treating the as-spun fiber under sufficient tension to maintain a constant length or to elongate the fiber up to about 5 percent of the as-spun length while heating within a range of about 150.degree. C. to about 650.degree. C. The resulting fibers have a tenacity of at least 15 grams per denier, an elongation of at least 1.5 percent, and an initial modulus of at least 400 grams per denier.

Abstract: A process of manufacturing fibers by forming a mixture of a solvent, a polymer and water and flashing the mixture through a nozzle. Water is present as a discontinuous phase in the mixture. The polymer may be any polymer capable of forming fiber, preferably a crystalline or a partially crystalline polymer. The preferred polymers are crystalline or partially crystalline polyolefins, preferably polyethylene or polypropylene. The discrete fibers thus formed can be easily refined and used for making paper webs.

Abstract: A process is provided for the manufacture of fibrils of short length by suddenly releasing the pressure acting on a two-phase liquid mixture of molten polymer and solvent and which is at a high pressure and a high temperature. The two-phase liquid mixture is ejected through a pressure release orifice so as to vaporize the solvent instantaneously and solidify the polymer, and the flow path of the two-phase liquid mixture is perturbed at the instant when it enters the pressure release orifice.Spinnerets are provided which have a perturbation chamber containing a supply orifice and a pressure release orifice.

Abstract: Fibrils of thermoplastic polymer, particularly crystalline thermoplastic polymers such as polyethylene and polypropylene, are prepared by forcing a dispersion of heat softened polymer particles in a liquid medium through a pair of opposed co-axial orifices. The liquid medium is preferably aqueous and is pressurized to prevent boiling. The resulting fibrils have some degree of molecular orientation, and may be useful in the production of reinforced paper.

Abstract: An improvement in the fibril formation process which includes dissolving at an elevated temperature an olefin polymer having an inherent viscosity of at least 3.5 in a hot hydrocarbon solvent, shearing the hot polyolefin solution to thereby orient the polymer molecules therein, passing the sheared solution through a cooling zone maintained at a temperature well below the precipitation temperature of the solution while maintaining the orientation of the polymer molecules within the solution to thereby precipitate by thermal means the polymer solute of the solution in the form of a solvent swollen fibrous strand, separating a substantial portion of the polymer solvent from the fibrous strand, chopping and then beating the chopped fibrous strand in a liquid which is a nonsolvent for the polymer and which is soluble in the polymer solvent for a time sufficient to break down the fibrous strand into a plurality of fibrils, and separating the fibrils from the nonsolvent liquid.

Abstract: This invention relates to a class of novel polyesters derived from derivatives of hydroquinone and bis(carboxyphenyl)ether and to the fibers and other shaped articles prepared therefrom. Also comprehended by this invention are the novel, optically anisotropic polyester melts from which these shaped articles can be prepared.

Abstract: Poly(N-acetyl-D-glucosamine) is soluble in hexafluoroisopropyl alcohol and hexafluoracetone sesquihydrate. The solutions formed may be wet or dry spun into filaments, or cast into films or solid articles, which may be used as absorbable surgical sutures, or other absorbable surgical elements. Poly(N-acetyl-D-glucosamine) is enzymatically degradable in living tissue, and is resistant to hydrolytic degradation, and, therefore, surgical elements thereof have good storage characteristics under a wide variety of conditions.

Abstract: Water-insoluble, water-swellable fibers adapted to bind aqueous fluids such as body exudates are prepared by spinning fibers from an organic solvent solution of a copolymer of maleic anhydride with suitable vinyl monomers. The copolymer solution also contains a small amount of a polyfunctional cross-linking agent such as a glycol or alkylene diamine which reacts to cross-link the copolymer chains when the fibers are heated and dried. The cross-linked copolymer fibers are then rendered hydrophilic and water-swellable by reaction with ammonia or an alkali metal hydroxide.