Disclosed is a method for mass-producing densified carbon nanotube fiber. The method includes preparing carbon nanotube fiber, swelling the carbon nanotube fiber by applying an acid solution thereto, and stretching the carbon nanotube fiber, coagulating the stretched carbon nanotube fiber so as to remove the acid solution present therein, and drying the coagulated carbon nanotube fiber.

A fabric containing nanotubes which is impervious to viruses, bacteria, and other pathogens; which is self-sterilizing and reusable; and a method of producing the same are disclosed. The fabric can be used to construct facemasks, gloves, protective suits, protective habitats, continuous air filtration/sterilization systems or any other type of protective clothing or structure. The fabric may have integrated temperature monitoring sensors. The fabric may be made into patches which may be integrated into existing articles of clothing. When connected to an electrical power source, either via built-in electrical connections or by induction, the active layer which is one of the components of the fabric will heat to a temperature high enough to eliminate potential biological contamination from viruses, bacteria and other microbial threats. Combining the CNT active layer with an insulating layer will allow a garment to be continuously worn or used without needing removal during multiple sterilization cycles.

A welding process may be configured to convert a substrate into a welded substrate by applying a process solvent to the substrate, wherein the process solvent interrupts one or more intermolecular force between one or more component in the substrate. The substrate may be configured as a natural fiber, such as cellulose, hemicelluloses, and silk. The process solvent may be configured as an ionic-liquid based solvent and the welded substrate may be a congealed network after the process solvent has been adequately swollen and/or mobilized the substrate. A welding process may be configured such that individual fibers of a substrate are not fully dissolved such that material in the fiber core may be left in the native state by controlling process variables. The welding process fibers may have a tenacity 10% or 20% greater or a diameter 25% less than that of a cellulosic-based yarn substrate.

A dyeing and welding process may be configured to convert a substrate into a welded substrate having at least some color imparted thereto via a dye and/or coloring agent by applying a process solvent having a dye and/or coloring agent therein to the substrate, wherein the process solvent interrupts one or more intermolecular force between one or more component in the substrate. The substrate may be configured as a natural fiber, such as cellulose, hemicelluloses, and silk. The process solvent may include a binder, such as dissolved biopolymer (e.g., cellulose). After application of a process solvent comprised of a dye and/or coloring agent, the substrate may be exposed to a second application of a process solvent comprised of a binder, which second application may occur before or after a process temperature/pressure zone, process solvent recovery zone, and/or drying zone.

The present invention relates to a surface-modified aramid fiber and a method for preparing the same. The method includes the following steps: modifying an aramid fiber having amino groups and carboxyl groups on the surface with siloxane γ-glycidoxypropyltrimethoxysilane to obtain a silicon methoxylated aramid fiber; reacting same with a cerium oxide coated with polydopamine modified chaotic boron nitride to obtain a surface-modified aramid fiber. The cerium oxide coated with polydopamine modified chaotic boron nitride has high ultraviolet absorption, and has extremely low catalytic activity, avoiding the damage to a fiber structure by photocatalysis during radiation, being an effective, safe and highly-efficient ultraviolet absorber. The surface-modified aramid fiber provided in the present invention has an ultraviolet-resistant function, high surface activity, good thermal performance, and better mechanical performance, providing excellent overall performance, and having higher utilization value. The method is simple and controllable, being suitable for large scale production.

A welding process may be configured to convert a substrate into a welded substrate by applying a process solvent to the substrate, wherein the process solvent interrupts one or more intermolecular force between one or more component in the substrate. The substrate may be configured as a natural fiber, such as cellulose, hemicelluloses, and silk. The process solvent may be configured as an ionic-liquid based solvent and the welded substrate may be a congealed network after the process solvent has been adequately swollen and/or mobilized the substrate. A welding process may be configured such that individual fibers of a substrate are not fully dissolved such that material in the fiber core may be left in the native state by controlling process variables. The welding process fibers may have a tenacity 10% or 20% greater or a diameter 25% less than that of a cellulosic-based yarn substrate.

A welded yarn may have a cross section about a plane that is perpendicular to the longitudinal axis of the welded yarn wherein the cross-sectional area is comprised of two or more distinct portions, wherein the degree of welding in each portion is different, which may also result in different fiber volume ratios compared to raw yarn substrates.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state.

All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state. All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

The present invention relates to methods of producing polymer fibers and polymer fiber products and materials recovery from these processes. It is an object of this invention to produce polymer fibers and products that include these fibers using selective dissolution of multicomponent fiber and to recover the dissolved polymer and solvent for subsequent use.