Abstract: BCF yarn is melt-spun, drawn and textured to provide morphologically stable BCF yarns. The yarn texturizing includes a relatively low efficiency fluid jet texturizer, that is a fluid jet texturizer operating at a sufficiently low fluid jet velocity and a sufficiently high fluid jet temperature to obtain a yarn skein shrinkage of less than about 0.50 inch, more preferably about 0.25 inch or less. Most preferably, the BCF yarns are formed of nylon-6 and exhibit an alpha-crystalline content of less than about 45%, and usually between about 45% to about 55%.

Abstract: BCF yarn is melt-spun, drawn and textured to provide morphologically stable BCF yarns. The yarn texturizing includes a relatively low efficiency fluid jet texturizer, that is a fluid jet texturizer operating at a sufficiently low fluid jet velocity and a sufficiently high fluid jet temperature to obtain a yarn skein shrinkage of less than about 0.50 inch, more preferably about 0.25 inch or less. Most preferably, the BCE yarns are formed of nylon-6 and exhibit an alpha-crystalline content of less than about 45%, and usually between about 45% to about 55%.

Abstract: Morphologically stable BCF yarns, and the methods and systems for making such BCF yarns are provided. More specifically, the BCF yarn is melt-spun, drawn and textured. The yarn texturizing includes a relatively low efficiency fluid jet texturizer, that is a fluid jet texturizer operating at a sufficiently low fluid jet velocity and a sufficiently high fluid jet temperature to obtain a yarn skein shrinkage of less than about 0.50 inch, more preferably about 0.25 inch or less. Most preferably, the BCF yarns are formed of nylon-6 and exhibit an alpha-crystalline content of less than about 45%, and usually between about 45% to about 55%.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions in the reactor zone to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. A spinneret zone downstream of the reactor zone thus receives the molten polycaprolactam directly from the reactor zone and forms a fiber therefrom by extruding it through the spinneret's fiber-spinning orifice.

Abstract: Morphologically stable BCF yarns, and the methods and systems for making such BCF yarns are provided. More specifically, the BCF yarn is melt-spun, drawn and textured. The yarn texturizing includes a relatively low efficiency fluid jet texturizer, that is a fluid jet texturizer operating at a sufficiently low fluid jet velocity and a sufficiently high fluid jet temperature to obtain a yarn skein shrinkage of less than about 0.50 inch, more preferably about 0.25 inch or less. Most preferably, the BCF yarns are formed of nylon-6 and exhibit an alpha-crystalline content of less than about 45%, and usually between about 45% to about 55%.

Abstract: Morphologically stable BCF yarns, and the methods and systems for making such BCF yarns are provided. More specifically, the BCF yarn is melt-spun, drawn and textured. The yarn texturizing includes a relatively low efficiency fluid jet texturizer, that is a fluid jet texturizer operating at a sufficiently low fluid jet velocity and a sufficiently high fluid jet temperature to obtain a yarn skein shrinkage of less than about 0.50 inch, more preferably about 0.25 inch or less. Most preferably, the BCF yarns are formed of nylon-6 and exhibit an alpha-crystalline content of less than about 45%, and usually between about 45% to about 55%.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: The end group content of polyamide in the solid state may be reduced by treating the polyamide with gas-phase acid, anhydride, or amine. Stain- or dye-resistant polyamide fibers can be made by reducing the number of amino end groups. Reduction in the number of carboxylic end groups reduces the rate of regeneration of starting monomers during extrusion.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: A process for manufacturing substantially 100% nylon 6 carpet provides a nylon 6 face yarn to a nylon 6 support means so that the yarn and the support means form a carpet having a face side which is displayed when the carpet is installed and a back that binds the face yarn to the support means wherein said binding is with molten or dissolved nylon 6.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: The end group content of polyamide in the solid state may be reduced by treating the polyamide with gas-phase acid, anhydride, or amine. Stain- or dye-resistant polyamide fibers can be made by reducing the number of amino end groups. Reduction in the number of carboxylic end groups reduces the rate of regeneration of starting monomers during extrusion.

Abstract: The end group content of polyamide in the solid state may be reduced by treating the polyamide with gas-phase acid, anhydride, or amine. Stain- or dye-resistant polyamide fibers can be made by reducing the number of amino end groups. Reduction in the number of carboxylic end groups reduces the rate of regeneration of starting monomers during extrusion.

Abstract: Bicomponent fibers of different cross-sections may be formed without changing the geometry of the spinneret orifices. More specifically, at least two polymers are co-melt-spun through an orifice of fixed geometry so as to achieve a bicomponent fiber having a desired cross-section. In order to change to a bicomponent fiber having a cross-section which is different, therefore, at least one of (1) the differential relative viscosity, (2) the relative proportions of the first and/or second polymers, and (3) the cross-sectional bicomponent distribution of the first and second polymers, is changed. In such a manner, therefore, a wide variety of bicomponent fibers having different cross-sectional geometries may be produced without changing the fixed geometry orifice through which the polymers are co-melt-spun. Thus, bicomponent fiber cross-sections may be "engineered" to suit a variety of needs without necessarily shutting down production equipment in order to change spinnerets.

Abstract: An inherently light- and heat-stabilized polyamide has at least one piperidine compound bonded to the backbone polymer chain and at least one 4-amino-2,2,6,6-tetramethylpiperidine compound bonded to the backbone polymer chain. The inherently light- and heat-stabilized polyamide may be used to form articles such as, for example, fibers, carpets, yarns, and textile fabrics.

Abstract: Novel bicomponent fibers have a polyamide domain and a contaminant-containing polymer domain which is embedded entirely within, and thereby completely surrounded by, the polyamide domain. The preferred bicomponent fibers have a sheath-core structure wherein the polyamide domain constitutes the sheath and the contaminant-containing polymer constitutes the core. Surprisingly, even though the core is formed of a contaminant-containing polymer (which is difficultly spinnable), the bicomponent fibers are readily spinnable and exhibit properties which are comparable in many respects to fibers formed from 100% polyamide. Preferably, the fibers are concentric sheath-core bicomponent fibers having an uncontaminated nylon-6 sheath and a core formed from nylon-6 having a relatively high level of contamination in the form of the cyclic dimer of caprolactam and/or nylon-6 derived from colored regenerated post-consumer nylon carpet fibers.

Abstract: Novel bicomponent fibers have a polyamide domain and a contaminant-containing polymer domain which is embedded entirely within, and thereby completely surrounded by, the polyamide domain. The preferred bicomponent fibers have a sheath-core structure wherein the polyamide domain constitutes the sheath and the contaminant-containing polymer constitutes the core. Surprisingly, even though the core is formed of a contaminant-containing polymer (which is difficultly spinnable), the bicomponent fibers are readily spinnable and exhibit properties which are comparable in many respects to fibers formed from 100% polyamide. Preferably, the fibers are concentric sheath-core bicomponent fibers having an uncontaminated nylon-6 sheath and a core formed from nylon-6 having a relatively high level of contamination in the form of the cyclic dimer of caprolactam and/or nylon-6 derived from colored regenerated post-consumer nylon carpet fibers.

Abstract: Bicomponent fibers of different cross-sections may be formed without changing the geometry of the spinneret orifices. More specifically, at least two polymers are co-melt-spun through an orifice of fixed geometry so as to achieve a bicomponent fiber having a desired cross-section. In order to change to a bicomponent fiber having a cross-section which is different, therefore, at least one of (1) the differential relative viscosity, (2) the relative proportions of the first and/or second polymers, and (3) the cross-sectional bicomponent distribution of the first and second polymers, is changed. In such a manner, therefore, a wide variety of bicomponent fibers having different cross-sectional geometries may be produced without changing the fixed geometry orifice through which the polymers are co-melt-spun. Thus, bicomponent fiber cross-sections may be "engineered" to suit a variety of needs without necessarily shutting down production equipment in order to change spinnerets.

Abstract: Colored bicomponent filaments have a particulate colorant dispersed throughout one of the fiber domains while another of the fiber domains is colorant-free. More specifically, the filaments have at least two distinct components arranged longitudinally coextensive with one another. The arrangement of the components may be a sheath/core structure or a side-by-side structure. One of the components contains a colorant and the other one does not (i.e., is colorant free). The colorant-free component is most preferably formed of a polymeric material which is incompatible with the particulate colorant, whereas the colorant-containing component is most preferably formed of a polymeric material which is compatible with the particulate colorant.