The present disclosure provides a polyamide resin and a preparation method therefor, a composition, and a fiber product. The polyamide comprises diamine structural units and diacid structural units, wherein 90 mol % or more of the diacid structural units are derived from adipic acid, 90 mol % or more of the diamine structural units are derived from 1,5-pentanediamine, and the polyamide resin contains a water-extractable substance in a content of 0.7 wt. % or less. The water-extractable substance has a number average molecular weight of 2000 or less. The preparation method of the polyamide resin of the present disclosure is simple without using large-scale equipment, and the process parameters thereof are easy to control, thereby facilitating mass production thereof. The polyamide resin of the present disclosure has a long spinneret wipe cycle time and less broken filament times, and the obtained fiber has less broken filaments, low yarn unevenness, less dyed dark grain, a good dyeing effect, and an excellent elongation at break, breaking strength and a lower boiling water shrinkage, a high spinning yield and a high dyeing yield.

Actuators (artificial muscles) comprising twisted polymer fibers generate tensile actuation when powered thermally. In some embodiments, the thermally-powered polymer fiber tensile actuator can be incorporated into an article, such as a textile or garment.

Actuators (artificial muscles) comprising twisted polymer fibers generate tensile actuation when powered thermally. In some embodiments, the thermally-powered polymer fiber tensile actuator can be incorporated into an article, such as a textile or garment.

A recycled-carbon-fiber tow composition comprising a recycled carbon fiber tow taken from a carbon-fiber-reinforced thermosetting resin molded body; and a surface modifier having a chemical functional group (hereinafter, referred to as second chemical functional group) that has chemical affinity with a chemical functional group (hereinafter, referred to as first chemical functional group) existing on a surface of the carbon fiber, wherein the recycled carbon fiber tow is formed such that carbon fibers are bundled into a tow with amorphous carbon that substantially contains no resin residue, the recycled-carbon-fiber tow composition contains 0.1 to 1 weight % of the surface modifier when an entirety of the recycled-carbon-fiber tow composition is 100 weight %, and n amount of residual carbon content measured when the recycled-carbon-fiber tow composition has been heated in a condition of 600? C.?60 minutes is 1 to 5 weight %.

A recycled-carbon-fiber tow composition comprising a recycled carbon fiber tow taken from a carbon-fiber-reinforced thermosetting resin molded body; and a surface modifier having a chemical functional group (hereinafter, referred to as second chemical functional group) that has chemical affinity with a chemical functional group (hereinafter, referred to as first chemical functional group) existing on a surface of the carbon fiber, wherein the recycled carbon fiber tow is formed such that carbon fibers are bundled into a tow with amorphous carbon that substantially contains no resin residue, the recycled-carbon-fiber tow composition contains 0.1 to 1 weight % of the surface modifier when an entirety of the recycled-carbon-fiber tow composition is 100 weight %, and n amount of residual carbon content measured when the recycled-carbon-fiber tow composition has been heated in a condition of 600? C.?60 minutes is 1 to 5 weight %.

Methods for fabricating coiled polymer fibers and yarns (high-spring-index coiled fibers and yarns). Methods include inserting twist separately into individual fibers or yarns, plying the fibers or yarns by inserting plying twist, setting the ply structure without permanently binding together the fibers or yarns of different plies so that the ply structure is substantially stable against untwist when torsionally untethered, and then unwrapping the plied fibers or yarns so that a high-spring-index fiber or yarn can be obtained. In some embodiments, the unwrapped fibers or yarns are further set so that these are further stabilized. The methods can eliminate the need for a mandrel, and can be quickly applied for applications where high-spring-index thermally-driven artificial muscles are presently employed, such as for presently commercialized comfort-adjusting jackets.

Methods for fabricating coiled polymer fibers and yarns (high-spring-index coiled fibers and yarns). Methods include inserting twist separately into individual fibers or yarns, plying the fibers or yarns by inserting plying twist, setting the ply structure without permanently binding together the fibers or yarns of different plies so that the ply structure is substantially stable against untwist when torsionally untethered, and then unwrapping the plied fibers or yarns so that a high-spring-index fiber or yarn can be obtained. In some embodiments, the unwrapped fibers or yarns are further set so that these are further stabilized. The methods can eliminate the need for a mandrel, and can be quickly applied for applications where high-spring-index thermally-driven artificial muscles are presently employed, such as for presently commercialized comfort-adjusting jackets.

A method, system, and resulting linear fibrous formation are provided wherein a supporting linear formation defines a core that is transported through a spinning chamber. A coating of polymeric nanofibers enveloping the supporting linear formation in the spinning chamber. The coating of polymeric nanofibers comprises a flat stripe wound around the core into a helical form, the flat stripe created from a hollow electrically neutral nanofibrous plume generated in a spinning space above a spinning electrode during spinning by AC electric voltage in the spinning chamber.

A method, system, and resulting linear fibrous formation are provided wherein a supporting linear formation defines a core that is transported through a spinning chamber. A coating of polymeric nanofibers enveloping the supporting linear formation in the spinning chamber. The coating of polymeric nanofibers comprises a flat stripe wound around the core into a helical form, the flat stripe created from a hollow electrically neutral nanofibrous plume generated in a spinning space above a spinning electrode during spinning by AC electric voltage in the spinning chamber.

A terry woven fabric includes hygro yarns structures. The hygro yarns are formed with soluble fibers, which are later removed, to define yarn structures with hollow cores.