Synthetic fibers with enhanced stain resistance, yarns and carpets prepared from these fibers and compounds and methods for their production are provided.

A method for manufacturing a dull polyamide 56 fiber includes steps as follows. Bright polyamide 56 chips are provided. A viscosity adjusting step is provided, wherein a relative viscosity in sulfuric acid of the bright polyamide 56 chips is adjusted to a range of 2.90 to 3.00. A moisture adjusting step is provided, wherein a moisture content of the bright polyamide 56 chips is adjusted to a range of 350 to 550 ppm. A spinning step is provided, which includes providing dull polyamide 6 chips and a blending step. The dull polyamide 6 chips include TiO.sub.2. In the blending step, the dull polyamide 6 chips and the bright polyamide 56 chips dealt with the viscosity adjusting step and the moisture adjusting step are melted and blended, and then spun at a temperature ranging from 275° C. to 285° C., thus the dull polyamide 56 fiber is obtained.

A method for manufacturing a dull polyamide 56 fiber includes steps as follows. Bright polyamide 56 chips are provided. A viscosity adjusting step is provided, wherein a relative viscosity in sulfuric acid of the bright polyamide 56 chips is adjusted to a range of 2.90 to 3.00. A moisture adjusting step is provided, wherein a moisture content of the bright polyamide 56 chips is adjusted to a range of 350 to 550 ppm. A spinning step is provided, which includes providing dull polyamide 6 chips and a blending step. The dull polyamide 6 chips include TiO.sub.2. In the blending step, the dull polyamide 6 chips and the bright polyamide 56 chips dealt with the viscosity adjusting step and the moisture adjusting step are melted and blended, and then spun at a temperature ranging from 275° C. to 285° C., thus the dull polyamide 56 fiber is obtained.

Provided is a polyamide fiber having excellent color developability, as well as a method for producing such a polyamide fiber, and a fiber structure. The polyamide fiber comprises a polyamide resin composition comprising a polyamide resin and an amino group-containing color enhancer, the polyamide fiber having terminal amino groups at a concentration of from 5.0 μeq/g to 40.0 μeq/g. Such a fiber can be produced by a production method at least comprising: melt-kneading a polyamide resin composition including a polyamide resin and an amino group-containing color enhancer to give a melt-kneaded product having a predetermined melt viscosity; and spinning the melt-kneaded product to give fibers.

Provided is a polyamide fiber having excellent color developability, as well as a method for producing such a polyamide fiber, and a fiber structure. The polyamide fiber comprises a polyamide resin composition comprising a polyamide resin and an amino group-containing color enhancer, the polyamide fiber having terminal amino groups at a concentration of from 5.0 μeq/g to 40.0 μeq/g. Such a fiber can be produced by a production method at least comprising: melt-kneading a polyamide resin composition including a polyamide resin and an amino group-containing color enhancer to give a melt-kneaded product having a predetermined melt viscosity; and spinning the melt-kneaded product to give fibers.

Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.

Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.

Polyamide-based fiber for artificial hair that is excellent in drip resistance, texture, and productivity is provided. According to the present invention, provided is fiber for artificial hair, including a resin composition containing: aliphatic polyamide; semi-aromatic polyamide with a skeleton obtained by polycondensation of aliphatic diamine and aromatic dicarboxylic acid; and a bromine-based flame retardant.

Polyamide-based fiber for artificial hair that is excellent in drip resistance, texture, and productivity is provided. According to the present invention, provided is fiber for artificial hair, including a resin composition containing: aliphatic polyamide; semi-aromatic polyamide with a skeleton obtained by polycondensation of aliphatic diamine and aromatic dicarboxylic acid; and a bromine-based flame retardant.

An artificial turf system for installation over a receiving surface is described. The artificial turf system comprising: a sheet member made of a flexible material, the sheet member defining a first surface for interfacing with the receiving surface and a second surface; primary yarns made of straight fibers backstitched in and threaded through the sheet member and upwardly extending from the sheet member to a first elevation; and secondary yarns made of textured fibers backstitched in and threaded through the sheet member and upwardly extending from the sheet member at a second elevation less than the first elevation which is caused by a difference in texture between the primary yarns and the secondary yarns, wherein the secondary yarns are more rigid than the primary yarns, and wherein the primary yarns and the secondary yarns have ends which are cut after being threaded through the sheet member.