A thermoplastic filament comprising multiple polymers of differing flow temperatures in a geometric arrangement and an interior channel containing a structural or functional thread therein is described. A method for producing such a filament is also described. Because of the difference in flow temperatures, there exists a temperature range at which one polymer is mechanically stable while the other is flowable. This property is extremely useful for creating thermoplastic monofilament feedstock for three-dimensionally printed parts, wherein the mechanically stable polymer enables geometric stability while the flowable polymer can fill gaps and provide strong bonding and homogenization between deposited material lines and layers. These multimaterial filaments can be produced via thermal drawing from a thermoplastic preform, which itself can be three-dimensionally printed. Furthermore, the preform can be printed with precisely controlled and complex geometries, enabling the creation of a filament or fiber with an interior thread contained within the outer, printed filament or fiber. This thread adds structural reinforcement or functional properties, such as electrical conductivity or optical waveguiding, to the filament.

A method of producing, from a continuous or discontinuous (e.g., chopped) carbon fiber, partially to fully converted metal carbide fibers. The method comprises reacting a carbon fiber material with at least one of a metal or metal oxide source material at a temperature greater than a melting temperature of the metal or metal oxide source material (e.g., where practical, at a temperature greater than the vaporization temperature of the metal or metal oxide source material). Additional methods, various forms of carbon fiber, metal carbide fibers, and articles including the metal carbide fibers are also disclosed.

A method of producing, from a continuous or discontinuous (e.g., chopped) carbon fiber, partially to fully converted metal carbide fibers. The method comprises reacting a carbon fiber material with at least one of a metal or metal oxide source material at a temperature greater than a melting temperature of the metal or metal oxide source material (e.g., where practical, at a temperature greater than the vaporization temperature of the metal or metal oxide source material). Additional methods, various forms of carbon fiber, metal carbide fibers, and articles including the metal carbide fibers are also disclosed.

Provided is a method of manufacturing high strength synthetic fibers, and high strength synthetic fibers manufactured using the same. More particularly, the method involves a localized heating process by raising the temperature of a molten spinning fiber to a temperature higher than that of a pack body during a short period of time with no degradation through a heating zone located in the immediate vicinity of capillary in the spinning nozzle, so as to effectively control the molecular entanglement structure in the molten polymer without reducing the molecular weight and thus to enhance the drawability of the as-spun fibers, thereby improving the mechanical properties of the as-spun fibers, such as strength, elongation, etc., using the existing processes of melt spinning and drawing and thus enabling a mass production of a high-performance fiber at low cost.

Multi-layered electrospun microfibers and/or microtubes, comprising cells and/or molecules of interest. The invention is further directed to compositions comprising said microfibers and/or microtubes and methods of use thereof in various applications.

A core-sheath conjugated fiber includes two kinds of polymer, wherein the core-sheath conjugated fiber is characterized in that the core component has projected shapes having projections and grooves alternately in a cross section in a direction perpendicular to the fiber axis, the projections are formed continuously in the direction of the fiber axis, and the height (H) of the projections, the width (WA) at the tip of the projections, and the width (WB) of the bottom surface satisfy the formulas at the same time:

1.0H/(WA).sup.1/23.0(1)

0.7WB/WA3.0(2).

There is provided a fiber and method of making a fiber. The fiber has an inner-volume portion having a first outer diameter, a plurality of nanostructures, and one or more first polymers. The nanostructures act as an orientation template for orientation of the one or more first polymers in a direction parallel to a longitudinal axis of the fiber. The fiber has an outer-volume portion having a second outer diameter and one or more second polymers. The outer-volume portion is in contact with and completely encompasses the inner-volume portion. The inner-volume portion has at least one of a tensile modulus and a strength that are higher than at least one of a tensile modulus and a strength of the outer-volume portion.

There is provided a fiber and method of making a fiber. The fiber has an inner-volume portion having a first outer diameter, a plurality of nanostructures, and one or more first polymers. The nanostructures act as an orientation template for orientation of the one or more first polymers in a direction parallel to a longitudinal axis of the fiber. The fiber has an outer-volume portion having a second outer diameter and one or more second polymers. The outer-volume portion is in contact with and completely encompasses the inner-volume portion. The inner-volume portion has at least one of a tensile modulus and a strength that are higher than at least one of a tensile modulus and a strength of the outer-volume portion.

There is provided a method of making a fiber having improved resistance to microfracture formation at a fiber-matrix interface. The method includes mixing a plurality of nanostructures and one or more first polymers in a first solvent to form an inner-volume portion mixture, mixing one or more second polymers in a second solvent to form an outer-volume portion mixture, spinning the inner-volume portion mixture and the outer-volume portion mixture to form a precursor fiber, heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and obtaining a fiber. The fiber has an inner-volume portion with a first outer diameter, the nanostructures, and with the one or more first polymers, and has an outer-volume portion with a second outer diameter and the one or more second polymers, the outer-volume portion being in contact with and completely encompassing the inner-volume portion.

The disclosure includes core-shell filament composition for additive manufacturing of ophthalmic lenses and ophthalmic lens components. The disclosure also includes a set of criteria for selecting core and shell thermoplastic combinations that exhibit high optical clarity, improved filament inter-strand diffusion, high inter-strand adhesion, and improved manufactured part strength when used in an additive manufacturing method like fused deposition modelling.