Abstract: Acrylic fibers are provided having superior abrasion resistance and flex fatigue properties as well as other properties desirable for end use applications in fabrics where wear performance properties are important, such as socks. The fibers may be made by a wet spinning process in which the spinbath consists of dimethylformamide and water where the concentration of the dimethylformamide is in the range of 72 to 84% by weight.

Abstract: Polyamide conjugate filaments are prepared by a spin-stretch process wherein two nylon 66 polymers having different relative viscosities are melt spun at a spinning speed of at least 2286 mpm to form filaments in which the polymers are arranged in a side-by-side configuration along the length of the filaments. The filaments are then stretched in-line at a stretch ratio greater than 1.0 prior to their being collected with said stretch ratio being selected to provide filaments having a high level of high-load crimp and a low level of boiling water shrinkage. The filaments are particularly useful in the construction of stretch garments and, especially, ladies' leg hose and pantyhose.

Abstract: Acrylic fibers having good basic dyeability characteristics are provided. The fibers are composed of an acrylic polymer having a sulfonate-containing nonacrylic polymer, such as a partially sulfonated polystyrene, dispersed therein.

Abstract: Polyamide conjugate filaments are prepared by a spinstretch process wherein two polyamides (e.g. two nylon 66 polymers) having different terminal velocity distances are melt spun at a spinning speed of at least 1829 mpm to form filaments in which the polymers are arranged in an eccentric configuration along the length of the filaments. The filaments are then stretched in-line at a stretch ratio greater than 1.0 prior to their being collected with the processing conditions and polyamides being selected to provide filaments having a high level of high-load crimp and a low level of boiling water shrinkage. The filaments are particularly useful in the construction of stretch garments and, especially, ladies' leg hose and pantyhose.

Abstract: A self-crimping multi-component polyester filament is provided and a process for producing the filament. In its simplest form, the filament is composed of two components each of which comprises a polyester of the same chemical composition and one of which contains a minor amount of a polyolefin admixed with the polyester. The filament is formed by co-extruding the components to form a conjugate filament that is attenuated in the molten state, solidified and then collected. Attenuation of the filament in the molten state imparts self-crimping properties and molecular orientation to the filament.

Abstract: A self-crimping multi-component polyamide filament is provided and a process for producing the filament. In its simplest form, the filament is composed of two components each of which comprises a polyamide of the same chemical composition and one of which contains a minor amount of a polyolefin admixed with the polyamide. The filament is formed by co-extruding the components to form a conjugate filament that is attenuated in the molten state, solidified and then collected. Attenuation of the filament in the molten state imparts self-crimping properties and molecular orientation to the filament.

Abstract: An acrylic fiber having improved basic dyeability and the method for making the same wherein an acrylic polymer containing a sulfonated vinyl monomer as a part thereof is dissolved in a suitable solvent to form a spinning dope and a solution of a second or additive polymer dissolved in the same solvent is added to the dope which is then spun to form fibers. The second polymer is selected from the group consisting of cellulose triacetate, polymethyl methacrylate, polyvinyl chloride, a polyamide of hexamethylenediamine with 1,1,3-trimethyl-5-carboxy-3-(p-carboxyphenyl) indane and a polyamide of hexamethylene diamine with isophthalic acid. The spin dope will contain 10 to 35 weight percent of polymer solids, with the amount of the second or additive polymer being 0.5 to 25 weight percent of the total polymer solids. Fibers spun from the dope have enhanced basic dyeability. The method is effective only when the acrylic polymer contains a sulfonated vinyl monomer as part of the acrylic polymer backbone.

Abstract: Disclosed is an acrylic fiber having improved basic dyeability. The fiber is made by a process wherein a copolymer of an acrylic monomer and a sulfonated vinyl monomer is dissolved in a solvent to form a spinning dope and a solution of polystyrene in the same solvent is added to the dope prior to spinning the dope to form fibers. The polystyrene will be in the form of a separate phase dispersed throughout the spinning dope and the fibers formed from the dope. Fibers formed from this polystyrene-containing dope have improved basic dyeability.

Abstract: An acrylic fiber having improved basic dyeability and hot/wet properties, the fiber being made up of a blend of (a) at least 60 weight percent of a polymer of at least 35 weight percent of acrylonitrile copolymerized with up to 65 weight percent of at least one other mono-olefinic monomer and a minor amount of a sulfonated vinyl monomer with (b) 0.5 to 40 weight percent of the polyterephthalamide of a mixture of 2,2,4 and 2,4,4 trimethyl hexamethylene diamine, the fiber being made up of a two-phase heterogeneous suspension of the polyterephthalamide in a continuous phase of the acrylic polymer. Without the sulfonated vinyl monomer the fiber will have superior hot/wet properties but will show no improvement in dyeability, the dyeability of the fiber being enhanced only when the sulfonated vinyl monomer is present as a part of the acrylic polymer chain.

Abstract: High strength fibers of arylene oxadiazole/arylene N-alkylhydrazide copolymers are prepared by a unique solution spinning process, whereby an arylene oxadiazole/arylene N-alkyloxadiazolium hydrosulfate copolymer in sulfuric acid or oleum is extruded into an aqueous coagulation medium in which concurrently a fiber is formed and the latter-mentioned copolymer undergoes a chemical transformation to provide the first-mentioned copolymer.

Abstract: A process for utilizing scrap aromatic oxadiazole/N-alkyhydrazide copolymer by dissolving the scrap copolymer in oleum thereby effecting degradation thereof and heating the resulting solution at a temperature between about 100.degree. C. and 160.degree. C. to form a polymer solution. Articles such as fibers can be shaped from this solution by combining the solution with an aqueous medium such as water.

Abstract: Fibers of arylene oxadiazole/arylene N-alkylhydrazide copolymer and of high tensile strength are prepared by a unique solution spinning process, whereby an arylene oxadiazole/arylene N-alkyloxadiazolium hydrosulfate copolymer in sulfuric acid or oleum is extruded into an aqueous coagulation medium in which concurrently a fiber is formed and the latter-mentioned copolymer undergoes a chemical transformation to provide the first-mentioned copolymer.