Provided are a CNT forest having favorable spinning properties, and as a method for producing such a CNT forest, a production method in which CNT forest 45 is formed by applying, as deposition base surface 44, a surface including at least one part of inner surface 43 in opening substrate 40 having interior space 42 communicating with an outside through open portion 41, and CNT forest 45 has spinnable portion 47 at end 46 on a side of open portion 41.

The subject matter disclosed herein relates generally to microdenier fabrics comprising fibrillated bicomponent fibers. The bicomponent fibers can be fibrillated mechanically by hydroentangling, where the hydroentangling energy is sufficient for fibrillating as well as entangling or bonding the fibers. The bicomponent fibers can have an island-in-the-sea configuration. The micro-denier fabrics can be woven, knitted, or nonwoven. A nonwoven fabric made from the bicomponent fibers can be formed by either spunbonding or through the use of bicomponent staple fibers formed into a web by any one of several means and bonded similarly to those used for the spunbonded filament webs.

Disclosed are methods of partially or fully fibrillating bicomponent filaments of the island-in-the-sea configuration by hydroentangling. The hydroentangling energy can both fibrillate the sea component as well as entangling the sea and island components for bonding. Fabrics that are made from these at least partially fibrillated and bonded fibers are also disclosed. These fabrics have low pressure drop and high efficiency and can be used for filters and masks.

A welding process may be configured to convert a substrate comprised of short staple fibers into a welded substrate having significantly increased strength as compared to the raw substrate. When applied to a one-dimensional substrate, such as a yarn, the welding process may also reduce the diameter of the welded substrate compared to that of the raw substrate. Additionally, the welding process may be configured to impart superior color properties to the welded substrate compared to the color properties of the raw substrate, which superior color properties may be very pronounced when performing a welding process on a raw substrate comprised of colored and/or dyed recycled fibers.

A method for making a fiber reinforcement with variations in transverse cross section is disclosed. The method includes forming a fiber comprising polymeric material and exposing the fiber to a heat treatment, such that at least a portion of the polymeric material at or near said surface of said fiber is at or above the melting point temperature and substantially all of the polymeric material at or near the core is below the melting point temperature. The method further includes cooling the fiber to a temperature below the melting point temperature.

A technique for stable, high-speed treatment of reinforcement fiber. In a state where a unidirectional fiber bundle is held between a supporting surface of a support and a pressing surface of a resonator ultrasonically vibrating in a pressing direction perpendicular to the supporting surface, a pressed part of the unidirectional fiber bundle pressed by the pressing surface is moved in a longitudinal direction of the unidirectional fiber bundle. By doing so, the unidirectional fiber bundle can be stably treated at high speed when the unidirectional fiber bundle is opened or impregnated with a resin.

The present disclosure relates to an oxidation fiber structure having an oxidation fiber, and the oxidation fiber has an oxidation layer and a core portion, wherein the oxidation layer covers the outer side of the core portion. The microwave processing unit is used to focus the microwave to perform an ultra-fast pre-oxidization process on the passed fiber yarn bunch, thus processing the fiber yarn bunch to form an oxidation fiber yarn bunch. An oxidization time of an oxidation fiber is reduced, and the cross section area of the oxidation layer of the oxidation fiber in the oxidation fiber yarn bunch generated by the microwave focusing oxidization process occupies more than 50% of the cross section area of the oxidation fiber in the oxidation fiber yarn bunch. Thus, the shell-core structure of the oxidation fiber can be reduced efficiently. Even, the oxidation fiber has no obvious shell-core structure.

The present disclosure relates to an oxidation fiber structure having an oxidation fiber, and the oxidation fiber has an oxidation layer and a core portion, wherein the oxidation layer covers the outer side of the core portion. The microwave processing unit is used to focus the microwave to perform an ultra-fast pre-oxidization process on the passed fiber yarn bunch, thus processing the fiber yarn bunch to form an oxidation fiber yarn bunch. An oxidization time of an oxidation fiber is reduced, and the cross section area of the oxidation layer of the oxidation fiber in the oxidation fiber yarn bunch generated by the microwave focusing oxidization process occupies more than 50% of the cross section area of the oxidation fiber in the oxidation fiber yarn bunch. Thus, the shell-core structure of the oxidation fiber can be reduced efficiently. Even, the oxidation fiber has no obvious shell-core structure.

The present invention pertains to a process for manufacturing one or more fluoropolymer fibers, said process comprising the following steps: (i) providing a liquid composition [composition (C1)] comprising: at least one fluoropolymer comprising at least one hydroxyl end group [polymer (F.sub.OH)L and a liquid medium comprising at least one organic solvent [solvent (S)]; (ii) contacting the composition (C1) provided in step (i) with at least one metal compound [compound (M)] of formula (I) here below: X.sub.4mAY.sub.m (I) wherein X is a hydrocarbon group, optionally comprising one or more functional groups, m is an integer from 1 to 4, A is a metal selected from the group consisting of Si, Ti and Zr, and Y is a hydrolysable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group, thereby providing a liquid composition [composition (C2)]; (iii) submitting to at least partial hydrolysis and/or polycondensation the composition (C2) provided in step (ii) thereby providing a liquid composition [composition (C3)] comprising at least one fluoropolymer hybrid organic/inorganic composite; (iv) processing the composition (C3) provided in step (iii) by electrospinning thereby providing one or more fluoropolymer fibers; (v) drying the fluoropolymer fiber(s) provided in step (iv); and (vi) optionally, submitting to compression the fluoropolymer fiber(s) provided in step (v) at a temperature comprised between 50 C. and 300 C. The invention also pertains to a process for the manufacture of said fluoropolymer fiber(s) and to uses of said fluoropolymer fiber(s) in various applications.

The present invention pertains to a process for manufacturing one or more fluoropolymer fibers, said process comprising the following steps: (i) providing a liquid composition [composition (C1)] comprising: at least one fluoropolymer comprising at least one hydroxyl end group [polymer (F.sub.OH)L and a liquid medium comprising at least one organic solvent [solvent (S)]; (ii) contacting the composition (C1) provided in step (i) with at least one metal compound [compound (M)] of formula (I) here below: X.sub.4mAY.sub.m (I) wherein X is a hydrocarbon group, optionally comprising one or more functional groups, m is an integer from 1 to 4, A is a metal selected from the group consisting of Si, Ti and Zr, and Y is a hydrolysable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group, thereby providing a liquid composition [composition (C2)]; (iii) submitting to at least partial hydrolysis and/or polycondensation the composition (C2) provided in step (ii) thereby providing a liquid composition [composition (C3)] comprising at least one fluoropolymer hybrid organic/inorganic composite; (iv) processing the composition (C3) provided in step (iii) by electrospinning thereby providing one or more fluoropolymer fibers; (v) drying the fluoropolymer fiber(s) provided in step (iv); and (vi) optionally, submitting to compression the fluoropolymer fiber(s) provided in step (v) at a temperature comprised between 50 C. and 300 C. The invention also pertains to a process for the manufacture of said fluoropolymer fiber(s) and to uses of said fluoropolymer fiber(s) in various applications.