A method of heating thermoplastic filament in additive manufacturing systems, such as 3D printing systems. In accordance with the illustrative embodiment of the present invention, the temporal rate $\frac{\mathrm{dE}}{\mathrm{dt}}$
at which heat dE is added to a portion of a segment of filament is a function of the temporal rate $\frac{dm}{\mathrm{dt}}$
at which the mass dm of the portion of the segment of filament is deposited. In particular, the temporal rate $\frac{\mathrm{dE}}{\mathrm{dt}}$
at which heat dE is added to a portion of a segment of filament is a non-linear function of the temporal rate $\frac{dm}{\mathrm{dt}}.$

The present invention provides a method for manufacturing a fiber reinforced resin material, the method including an opening step of opening an elongated fiber bundle to be widened in a width direction thereof to be put into a flat state; and a heat setting step of heat-setting the opened fiber bundle in the flat state by heating. In addition, the present invention provides an apparatus for manufacturing a fiber reinforced resin material containing a plurality of fiber bundles and a resin, the apparatus including an opening section that opens an elongated fiber bundle to be widened in a width direction thereof to be put into a flat state; and a heat setting section that heat-sets the opened fiber bundle in the flat state by heating.

The present invention provides a method for manufacturing a fiber reinforced resin material, the method including an opening step of opening an elongated fiber bundle to be widened in a width direction thereof to be put into a flat state; and a heat setting step of heat-setting the opened fiber bundle in the flat state by heating. In addition, the present invention provides an apparatus for manufacturing a fiber reinforced resin material containing a plurality of fiber bundles and a resin, the apparatus including an opening section that opens an elongated fiber bundle to be widened in a width direction thereof to be put into a flat state; and a heat setting section that heat-sets the opened fiber bundle in the flat state by heating.

A heat-treated cord comprising a low modulus yarn core that is wrapped by a plurality of high modulus wrapping yarns that were heat-treated for a time at a temperature and under a load sufficient to provide a free shrinkage of at least 2 percent and a shrinkage force of at least 3 pounds.

A heat-treated cord comprising a low modulus yarn core that is wrapped by a plurality of high modulus wrapping yarns that were heat-treated for a time at a temperature and under a load sufficient to provide a free shrinkage of at least 2 percent and a shrinkage force of at least 3 pounds.

Highly twisted, coiled polymer actuators (TCPAs) are made by twisting polymer monofilaments in a first direction, plying the monofilaments in a second, opposite direction to form a yarn, then coiling the yarn. The resulting coil is annealed to form a functional TCPA. The disclosed manufacturing method is based on the false-twisting principle, and produce twisted filaments and twist-stable yarns continuously and rapidly. The twisted monofilaments can be associated with wires for heating and sensing. Because the yarns are twist-stable, they can be processed on standard textile machines to form contracting artificial muscles.

Highly twisted, coiled polymer actuators (TCPAs) are made by twisting polymer monofilaments in a first direction, plying the monofilaments in a second, opposite direction to form a yarn, then coiling the yarn. The resulting coil is annealed to form a functional TCPA. The disclosed manufacturing method is based on the false-twisting principle, and produce twisted filaments and twist-stable yarns continuously and rapidly. The twisted monofilaments can be associated with wires for heating and sensing. Because the yarns are twist-stable, they can be processed on standard textile machines to form contracting artificial muscles.

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 fabrication method of a sheathed yarn includes the following steps: making a core run axially through a sheathing area; winding a sheathing fibre around the core in the sheathing area; and presenting a microelectronic chip fixed onto the core in the sheathing area. A polymer material is present between the microelectronic chip and the core when the sheathing step is performed. The polymer material creeps during the sheathing step to form a protective coating.