Abstract: Filaments of ethylene terephthalate polyester copolymers that contain a lithium salt of a glycollate of 5-sulfo-isophthalic acid provide improvements over commercially-available basic-dyeable polyester filaments.

Abstract: A process is provided for preparing basic-dyeable polyester polymer, and shaped articles therefrom, such as fibers, films and bottles, involving using the metal sulfonate salt of a glycollate of isophthalic acid as a polymerization catalyst in making ethylene terephthalate polyester copolymers. This reduces or even avoids the need to add a conventional polymerization catalyst, such as antimony trioxide, especially when making polyesters delustered with titanium dioxide.

Abstract: Polyester filaments in spin-oriented feed yarns, such as DTFY, and in draw-textured and other drawn yarns therefrom, and in fabrics and garments of such yarns, are prepared by an improved process involving treatment of the freshly-extruded polyester filaments with caustic in the spin-finish, so as to improve moisture-wicking properties.

Abstract: Drawn polyester multi-filament yarns, preferably prepared by a coupled process of spin-drawing, and of fabrics and garments thereof, are prepared by an improved process involving treatment of freshly-extruded polyester filaments with caustic in the spin-finish, so as to improve moisture-wicking properties.

Abstract: Polyester crystalline filaments that have been prepared by spin-orientation, and filaments prepared by drawing such filaments without texturing, in yarns thereof, and in fabrics and garments thereof, are prepared by an improved process involving treatment of freshly-extruded polyester filaments with caustic in the spin-finish, so as to improve moisture-wicking properties.

Abstract: Modifying a polyester with special chain-brancher residues in carefully controlled amounts to provide a draw-texturing feed yarn that can be draw-textured at a speed of 1,000 mpm without excessive filament breaks, and with other advantages in the resulting textured yarns, such as improved bulk and dyeability over prior polyester yarns that could not be satisfactorily textured under similar conditions.

Abstract: Modifying a polyester with tetraethyl silicate or like oxysilicon chain-brancher to provide a draw-texturing feed yarn that can be draw-textured at a speed of at least 500 mpm without excessive filament breaks, and with other advantages in the resulting textured yarns, such as improved bulk and dyeability over unmodified polyester yarns textured under similar conditions, and preferably without sacrificing dye uniformity.

Abstract: Modifying a polyester with tetraethyl silicate (or like oxysilicon chain-brancher) to provide a draw-texturing feed yarn that can be draw-textured at a speed of 1,000 mpm without excessive filament breaks, and with other advantages in the resulting textured yarns, such as improved bulk and dyeability over unmodified polyester yarns textured under similar conditions, and preferably without sacrificing dye uniformity.

Abstract: The disclosure relates to cospinning and drawing polyester filaments to produce a composite yarn which develops bulk due to differential shrinkage of the filaments when heated. Filaments of ethylene terephthalate synthetic linear condensation polymer are melt spun to form two separate filament bundles, a water-based spring finish is applied to the filaments of one bundle and a substantially non-volatile spin finish is applied to filaments of the other filament bundle, the filament bundles are drawn under identical treatment conditions during passage along separate paths and the filaments are then combined and intermingled during passage around draw rolls. The product is a mixed-shrinkage yarn wherein the filaments treated with aqueous-based finish have a higher heat-shrinkage than the filaments treated with non-volatile finish, even though both are otherwise processed in the same manner.

Abstract: Mixed-shrinkage, continuous-filament, heat-bulkable yarn, composed of low and higher shrinking filaments of different polyester compositions, develops worstedlike bulk in fabric as a result of fabric finishing operations. The yarn is prepared from two ethylene terephthalate polyesters, of different compositions and relative viscosities, by cospinning, drawing and heat-setting the filaments under identical, critically-controlled conditions.