Abstract: The present invention concerns a process for making a polyareneazole multifilament yarn comprising: a) extruding a solution comprising polyareneazole polymer and polyphosphoric acid through a plurality of orifices to produce filaments; b) forming a multifilament yarn from said filaments; c) hydrolyzing at least some of the polyphosphoric acid in the yarn by heating the yarn to a temperature above about 120° C. for up to about two minutes; d) washing at least some of the hydrolyzed polyphosphoric acid from the yarn; e) drying the washed yarn; f) optionally, heating the yarn above about 300° C., and g) collecting the yarn at a speed of at least about 50 meters per minute.

Abstract: A process for wet spinning a meta-aramid polymer solutions having a salt content of at least 3 percent by weight produces a one step, fully wet drawable fiber that has desirable physical properties without subjecting the fiber to hot stretching.

Abstract: In the preparation of poly(m-phenylene isophthalamide) filaments, hydrogen chloride is removed from as-produced amide solution of poly(m-phenylene isophthalamide) by contact with basic ion exchange resin.

Abstract: Hydrogen chloride is stripped from spent basic ion exchange resin by treatment with a solution of a tertiary amine in an amide solvent. The eluent solution is treated with anhydrous ammonia to precipitate ammonium chloride. The solution of tertiary amine in amide solvent is separated from the precipitate and may be used to regenerate spent resin.

Abstract: Spun yarns are made at high speeds of up to 220 meters per minute, using spinning techniques in which air is used to twist the fibers of a three component blend, one component of which consists of staple fibers made from electrically conductive filaments having a denier no greater than 2.5 times the denier of the filaments of the other components.

Abstract: PEKK fiber is dyed with a disperse dye in an organic dye carrier.

Abstract: The addition of certain fluorinated additives to aramid spin dopes prior to fiber spinning provides fiber of improved hydrolytic stability.

Abstract: A diamine salt and a surfactant are imbibed into never-dried aromatic polyamide fibers which may be printed or overprinted with acid dyes, after drying.

Abstract: Staple fibers having a crimp frequency in the range of 3 to 6 crimps per centimeter are mae by a process including a co-crimping step in which conductive and nonconductive filaments are crimped together.

Abstract: Staple fibers having a crimp frequency in the range of 3 to 6 crimps per centimeter are made by a process including a co-crimping step in which conductive and nonconductive filaments are crimped together.

Abstract: Hydrogen chloride evolution is reduced in the distillation of chloroform from its admixture with an amide solvent when in contact with stainless steel, by incorporation of certain tertiary aliphatic amines.

Abstract: A process for diffusing and subliming water-soluble and water-insoluble materials into never-dried, shrinkable aromatic polyamide fibers, using steam heated at certain controlled temperatures, within a specially designed treatment chamber and a process and apparatus for treating a tow of shrinkable material.