Abstract: Apparatus for charging and forwarding a group of filaments to a web formation zone wherein an attenuator forwards the group of filaments along a path into impingement with a target electrode positioned downstream from the attenuator and in the filament path, a charging electrode being positioned to cooperate with the target electrode to form a filament-charging electric field at the location where the filament group impinges and is being spread by the target electrode. The filaments are advanced in such a manner that the filaments are in a bundle configuration prior to contact with the target electrode and are free to spread from the bundle configuration to a fan configuration as they pass through and are charged by the electric field. The apparatus is provided with a plurality of attenuators and associated charging electrodes positioned on opposite sides of the target electrode in a staggered relationship to spread filament bundles into fan configurations and forward the filaments to the web formation zone.

Abstract: In a strand forming machine wherein a polymeric strand in molten form is fed downward into and through an upright tube positioned below the surface of a liquid quenching medium in a container having a bottom and side walls, the improvement comprising a hollow element mounted in the container and surrounding the tube, the hollow element extending above the side wall of the container and having a channel extending outwardly over the wall of the container in such a manner that in the event the strand fails to pass through the tube the excess molten strand will accumulate in and flow outward through the channel to a location outside the container.

Abstract: A semi-continuous polyester esterification process employing continuous feeding and discontinuous withdrawal is combined with a plurality of batch polycondensation processes to produce outstanding polyester polymer with improved flexibility (of process and product) and efficiency.

Abstract: Polyester fibers are dissolved and solid linear polyester polymer recovered for use in the production of new linear polyester products, particularly polyester fibers or filaments, by the process of dissolving the fibers in a non-depolymerizing dissolution solvent for polyester characterized by inclusion of carbocyclic rings in its structural formula under dissolution conditions for polyester polymer; thereafter quenching the polyester solution; and separating the solid polyester from the solution.

Abstract: A method for stretching a tow of filaments wherein the tow is passed under tension through a chamber, the chamber having openings at the ends thereof for passage of the tow, and streams of heated liquid are forced transversely through the tow at the chamber openings at a critical minimum rate at least as great asx = 3,000T.sqroot.(WN/h(.mu./.rho.)where x is the heated liquid flow rate in gallons per minute through each opening, T is the thickness of the streams of heated liquid in inches at said openings, W is the width of the openings and the liquid streams in inches, h is the height or thickness in inches that the tow is free to assume in passing through the openings, N is the number of filaments in the tow, .mu. is the viscosity of the heated liquid in pounds per foot-second and .rho. is the density of the heated liquid in pounds per cubic foot.

Abstract: Thermoplastic multifilament feed yarns, such as polyester feed yarns are heatset in a twisted state at a temperature and under a tension so as to produce a torque yarn; and thereafter continuously, and at substantially the same tension, cooled, detwisted, and subjected to a second heat treatment so as to reduce the torque. If undrawn or partially drawn feed yarn is employed, the yarn may be orientation drawn during the texturing process.

Abstract: Fire retardant qualitites are incorporated into polyester fibers by adding to the polymer, prior to spinning thereof into filaments, not more than about 25 percent, based on the weight of the polymer, of a compound having the general formula: ##STR1## WHERE R is a radical selected from the group consisting of alkyl, aromatic and brominated aromatic; x = 2-4; and n = 1-100.

Abstract: Strand granulation machines characterized by cutter bearing rotors and strand passages wherein continuous strands are passed through generally cross-sectionally circular shear bushings at the exit end of which that they are engaged and severed by the rotating cutters are improved by employing spring-loaded rotating cutters in working relationship with a cutter positioning cam to move the cutters reciprocally generally along the radius of the circle generated by their sweep of rotation.

Abstract: Method for charging and forwarding a group of filaments to a web formation zone wherein an attenuator forwards the group of filaments along a path into impingement with a target electrode positioned downstream from the attenuator and in the filament path, a charging electrode being positioned to cooperate with the target electrode to form a filament-charging electric field at the location where the filament group impinges and is being spread by the target electrode. The filaments are advanced in such a manner that the filaments are in a bundle configuration prior to contact with the target electrode and are free to spread from the bundle configuration to a fan configuration as they pass through and are charged by the electric field.

Abstract: Strand granulation apparatus characterized by cutter bearing rotors and strand passages wherein the strands are passed through generally cross-sectionally circular shear bushings at the exit end of which they are engaged and severed by the rotating cutters are improved by employing shear bushings having noncircular cross-sections so disposed as to provide random positioning of strands when engaged by the cutters.

Abstract: Biscarbodiimides which are known to be effective as a surface application for polyethylene terephthalate fibers in lowering carboxyl end group concentration of the fibers and increasing hydrolytic stability, are prepared by the dehydration of ureas with triphenylphosphine and carbon tetrachloride.

Abstract: Fire retardant qualities are incorporated into polyester fibers by adding to the polymer, prior to spinning thereof into filaments, not more than about 20 percent, based on the weight of the polymer, of a compound containing two six membered phosphorus-containing heterocyclic rings having carbon, oxygen and phosphorus in the heterocyclic ring.

Abstract: Vinyl sulfonate monomers are recovered from an aqueous stream by bringing the stream into contact with activated carbon to allow the carbon to adsorb the monomers from the stream. The sulfonate monomers are subsequently removed from the carbon by bringing an aqueous solution of acrylonitrile into contact with the carbon. The acrylonitrile replaces the sulfonate monomers on the carbon to thereby desorb the sulfonate monomers into the solution in a concentration such that the solution is suitable as a feed stream to a polymerization reactor. The sulfonate monomers have the formula ##EQU1## where R.sub.1 is --H or --CH.sub.3, R.sub.2 is --CH.sub.2 -- or ##EQU2## in which R.sub.3 and R.sub.4 are either --H or --CH.sub.3 and X is H, Na or K.

Abstract: Vinyl sulfonate monomers are recovered from an aqueous stream by bringing the stream into contact with activated carbon to allow the carbon to adsorb the monomers from the stream. The sulfonate monomers are subsequently removed from the carbon by bringing an aqueous solution of acrylonitrile into contact with the carbon. The acrylonitrile replaces the sulfonate monomers on the carbon to thereby desorb the sulfonate monomers into the solution in a concentration such that the solution is useful as a feed stream directly to a polymerization reactor. The sulfonate monomers have the formula ##SPC1##Where R.sub.1 is --H or --CH.sub.3, R.sub.2 is --CH.sub.2 O--, --O--, or --CH.sub.2 , n is 0 or 1 and X is Na, K or H.

Abstract: A continuous process is provided for the drying, crystallizing and solid state polymerization of fiber-forming crystallizable polyesters by subjecting polyester pellets of a specific viscosity of about 0.34, with a carboxyl concentration of about 15 milequivalents per gram and a particle size of between -10 and +20 mesh, to a temperature of not more than about 80.degree.C. until the water content of the flake is below 0.05%; and then raising the temperature to about 230.degree.-240.degree.C. until the specific viscosity of the polymer is equal to or greater than about 0.55.

Abstract: The method of making an acrylic spinning solution wherein a wet acrylonitrile-containing polymer is mixed with a solvent for the polymer to form a slurry, the slurry then being heated under pressure to obtain a polymer solution wherein the polymer is in solution in the solvent. The polymer solution is then passed through an elongated vaporization zone in which the pressure is decreased along the zone to provide a predetermined pressure profile along the length of the zone. The pressure profile through the zone is maintained above the polymer gel profile to remove most of the water while keeping the polymer in solution throughout the vaporizaton zone.

Abstract: Method and apparatus for charging filaments moving along a path wherein the filaments are passed across the face of a target electrode in a sheet of moving air and a plurality of corona discharge electrodes arranged in a row extending in the direction of filament travel apply an electric charge to the filaments to separate them. The corona discharge electrodes are positioned along the filament path between the point where the filaments impinge the target electrode and the point where the air stream velocity has decreased to about the velocity of the filaments.

Abstract: A spinnerette comprising a hollow spinning element having therein a plurality of radially extending spinning apertures positioned in arrays extending around the periphery of the element. A spinning composition forced axially into the spinning element through the ends thereof is extruded by the orifices in radial directions to form filaments.

Abstract: Method for making substantially void-free fibers having improved abrasion resistance wherein a spinning dope is formed by dissolving a dry acrylonitrile-containing polymer in a solvent/water mixture to form a spin dope which is wet spun at a temperature within the range of about 40.degree.C to about 75.degree.C. More specifically, the dope will contain from about 20 to about 28 weight percent of the polymer dissolved in a solvent containing about 1 to 8 weight percent water, based on the weight of the dope, with the solvent and water being mixed prior to contact with the polymer. The presence of water in the solvent brings about an improvement of the filamentary gel structure which results in fibers having enhanced durability and abrasion resistance.