Abstract: Deep-dyeing conjugate filaments are melt-spun by merging molten sub-streams of incompatible polymers to form combined streams, then quenching the combined streams to form the conjugate filaments. The filaments are preferably cold drawn prior to winding, increasing the bulk level in a fabric containing the filaments and increasing the dye stability of the filaments. When the sub-streams are merged outside of the spinneret, the filaments split into the sub-filaments upon exposure to boiling water while under no tension. When the sub-streams merge within the spinneret, the filament is not readily split into sub-filaments, but forms a helically crimped filament.

Abstract: A polyester yarn having filaments with aperiodic varying shrinkage levels along their lengths, the filaments having within-filament and between-filament shrinkage C.V.'s of at least 10%. The yarn may be made by conventional melt spinning within a critical narrow range of spinning speeds wherein yarn shrinkage decreases rapidly with spinning speed. A greige fabric incorporating the yarn as filling is textured by shrinking the unrestrained fabric, then heating the fabric sufficiently to cause the yarn to elongate.

Abstract: Polyester polymer is extruded through converging capillaries at different speeds to merge and form a combined stream. The stream is cooled to form a filament, which is withdrawn at a high speed. A plurality of such filaments are combined into yarn which self-crimps upon heating. In some embodiments, the yarn has a variable denier.

Abstract: Molten polymer streams are separately metered to the individual capillaries of a combined orifice, rendering the yarn produced less dependent on the capillary dimensions.

Abstract: Two molten streams of polyester polymer are extruded at different speeds to intersect below the spinneret. The spinning speed is relatively high, and the resulting filament has shrinkage peaks and valleys along its length. When a number of such filaments are relaxed in a yarn bundle, the yarn spontaneously develops crimp.

Abstract: Molten polymer streams are separately metered to the individual capillaries of a combined orifice, rendering the yarn produced less dependent on the capillary dimensions.

Abstract: Spun yarn having torqueless latent crimp is draw-textured, producing a drawn textured yarn which is substantially torque-free.

Abstract: A textured melt-spun filament having alternate S-twisted and Z-twisted helical sections connected by twist reversal regions, the filament having a cross-section comprising a spiral wherein the outer portion of the spiral lies at the inside of the helical sections.

Abstract: In spinning, the orifice is in the form of a slot meandering back and forth across the interface between two conjugated polymers flowing through the orifice.

Abstract: Nylon 66 yarn having particular stress-strain properties, typically also having a soft, luxuriant hand in fabric form. As compared to conventional nylon 66 with comparable boiling water shrinkage, the novel yarn exhibits a higher modulus at break, a lower modulus at 10% elongation, a positive stress index, and excellent denier uniformity. The process involves subjecting the yarn, within 0.016 to 0.11 seconds after solidification of the filaments, to a tension of 0.2 and 1.5 grams per final denier and heating the yarn to a temperature between 50.degree. and 250.degree. C. long enough to reduce yarn retraction below 1%.

Abstract: A textured melt-spun filament having alternate S-twisted and Z-twisted helical sections connected by twist reversal regions, the filament having a cross-section comprising a spiral wherein the outer portion of the spiral lies at the inside of the helical sections.

Abstract: Polyester yarn is spun at a sufficiently high speed to produce substantial stress-induced crystallinity and low shrinkage. The resulting feed yarn is textured, yielding a textured yarn which dyes considerably deeper than conventional polyester yarns.

Abstract: Nylon 66 yarn having particular stress-strain properties, typically also having a soft, luxuriant hand in fabric form. As compared to conventional nylon 66 with comparable boiling water shrinkage, the novel yarn exhibits a higher modulus at break, a lower modulus at 10% elongation, a positive stress index, and excellent denier uniformity. The process involves subjecting the yarn, within 0.016 to 0.11 seconds after solidification of the filaments, to a tension of 0.2 and 1.5 grams per final denier and heating the yarn to a temperature between 50.degree. and 250.degree. C. long enough to reduce yarn retraction below 1%.