A leader 10 for fly fishing proposed herein is formed of a single monofilament line. The leader 10 for fly fishing includes a tippet section 11 to which a fly is tied, a butt section 12 to which a fly line is tied, and an intermediate section 13 provided between the tippet section 11 and the butt section 12. Herein, the butt section 12 is thicker than the tippet section 11. The intermediate section 13 includes a front tapered portion 13a having a thickness that gradually increases from the tippet section 11, a rear tapered portion 13b having a thickness that gradually increases from the butt section 12, and a thicker portion than the butt section 12.

Provided is an airbag base fabric that has a low air permeability sufficient to ensure the safety of occupants and heat resistance sufficient to withstand high-power, high-temperature gas generated from a recent downsized inflator, and that is capable of being packaged compactly. Also provided is an airbag comprising the base fabric. An airbag base fabric comprising a synthetic fiber multifilament having a total fineness of 500 to 750 dtex, the airbag base fabric having an areal weight of 225 to 245 g/m.sup.2, air permeability at 20 kPa of 0.2 to 0.8 L/cm.sup.2/min, and edgecomb resistance according to the ASTM D 6479 method of 300 to 600 N in both warp and weft directions.

Provided is an airbag base fabric that has a low air permeability sufficient to ensure the safety of occupants and heat resistance sufficient to withstand high-power, high-temperature gas generated from a recent downsized inflator, and that is capable of being packaged compactly. Also provided is an airbag comprising the base fabric. An airbag base fabric comprising a synthetic fiber multifilament having a total fineness of 500 to 750 dtex, the airbag base fabric having an areal weight of 225 to 245 g/m.sup.2, air permeability at 20 kPa of 0.2 to 0.8 L/cm.sup.2/min, and edgecomb resistance according to the ASTM D 6479 method of 300 to 600 N in both warp and weft directions.

The method for producing wet spun fibers/a wet formed film using a double-walled pipe type micronozzle apparatus according to the present invention is a production method, wherein, in a step of extruding an internal phase comprising a fiber/film material and a good solvent for the fiber/film material in a linear form from the circular/rectangular end of the internal pipe of the apparatus into an external phase comprising a poor solvent for the fiber/film material, the external phase flowing in the external pipe of the apparatus, the ratio of the external phase flow rate to the internal phase flow rate is set to 1 or more, and further for the wet spun fibers, the external phase line speed at the orifice portion at which the internal phase and the external phase merge is set to 0.1 ms.sup.−1 or more.

An actuator device and method of manufacturing the same that includes at least two or more panels disposed in a frame is disclosed. Each of the two or more panels include a first rotationally-actuating artificial muscle fiber section between a first contact point of the frame and a tether point located on the panel and a second rotationally-actuating artificial muscle fiber section between the tether point and a second contact point on the frame. The tether point is approximately halfway across the length of the panel. A first and second muscle support is disposed on the panel between the tether point and the first contact point. The actuator device also includes a synchronization rod attached to the at least two or more panels.

An ultrafine fiber has a fiber diameter (D) of 100 to 5000 nm, a ratio (L/D) of a fiber length (L) to the fiber diameter (D) of 3000 to 6000, and a carboxyl terminal group amount of 40 eq/ton or more. At least a part of a surface layer of the ultrafine fiber may be formed of polyester.

Actuators (artificial muscles) comprising twist-spun nanofiber yarn or twist-inserted polymer fibers generate actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize polymer fibers non-coiled or coiled yarns and can be either neat or comprising a guest. Devices comprising these artificial muscles are also described. In some embodiments, thermally-powered polymer fiber torsional actuator has a twisted, chain-oriented polymer fiber that has a first degree of twist at a first temperature and a second degree of twist at a second temperature in which the bias angles of the first degree and second degree of twist are substantially different.

Actuators (artificial muscles) comprising twist-spun nanofiber yarn or twist-inserted polymer fibers generate actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize polymer fibers non-coiled or coiled yarns and can be either neat or comprising a guest. Devices comprising these artificial muscles are also described. In some embodiments, thermally-powered polymer fiber torsional actuator has a twisted, chain-oriented polymer fiber that has a first degree of twist at a first temperature and a second degree of twist at a second temperature in which the bias angles of the first degree and second degree of twist are substantially different.

Provided are a sea-island type composite multifilament which includes a thermoplastic elastomer resin as an island component, and an ultrafine multifilament prepared from such a sea-island type composite multifilament. The sea-island type composite multifilament includes an island component and a sea component. The island component includes a thermoplastic elastomer resin (A) having at least one of a Shore A hardness of 90 or less, a Shore D hardness of 60 or less, or a Rockwell hardness (R scale) of 70 or less. The sea component includes a water-soluble or easily alkali-soluble thermoplastic resin (B). The sea-island type composite multifilament has an average single island diameter of 8000 nm or less.

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.