The present invention relates to a preparation method of para-aramid nanofibers, and belongs to the technical field of novel polymer materials. The para-aramid nanofibers prepared in the present invention have a diameter of 10-100 nm, and a length of hundreds of microns. The preparation method includes: adding a certain amount of surfactant in a PPTA low-temperature polymerization process, and controlling aggregation of PPTA molecules along with growth of a PPTA molecule chain, thereby preparing the para-aramid fibers with a uniform size and an adjustable nano-scale diameter under assistance of other means (e.g., a coagulator and high-speed shearing dispersion). The present invention is short in production process and simple in equipment, can realize stable batch production to meet needs of large-scale production of the para-aramid nanofibers, has wide application prospects and can be applied to preparing a lithium-ion battery separator, a high-performance composite material and the like.

A tire grade oiled and non-oiled nylon 6.6 drawn and undrawn scrap yarns is converted to a recycled nylon 6.6 pellet. The recycled nylon 6.6 pellet is used with virgin nylon 6.6 pellet in a different ratio to produce tire grade recycled nylon 6.6 yarn.

A tire grade oiled and non-oiled nylon 6.6 drawn and undrawn scrap yarns is converted to a recycled nylon 6.6 pellet. The recycled nylon 6.6 pellet is used with virgin nylon 6.6 pellet in a different ratio to produce tire grade recycled nylon 6.6 yarn.

The disclosed method relates to a method of recycling high relative viscosity nylon. The process involves melting a base polyamide with a dry blended mixture of dicarboxylic acid and a second polyamide. The disclosed method provides a process of controlling the relative viscosity of the combined polyamides and, in various aspects, the second polyamide may be nylon plop or other polyamide having high relative viscosity.

The disclosed method relates to a method of recycling high relative viscosity nylon. The process involves melting a base polyamide with a dry blended mixture of dicarboxylic acid and a second polyamide. The disclosed method provides a process of controlling the relative viscosity of the combined polyamides and, in various aspects, the second polyamide may be nylon plop or other polyamide having high relative viscosity.

The present invention discloses a method for preparing untwisted, hollow, high-count textiles comprising the following steps: a. preparing an alkaline degradable slice; b. preparing a blended spun melt; c. preparing an easily alkaline soluble and degradable fiber by spinning; d. preparing the textiles or an embroidered article. A method for recovering the solute in an alkaline lysis solution comprises an alkaline lysis solution obtained after the degradation of the easily alkaline soluble and degradable fiber is subjected to an acid precipitation, so as to produce terephthalic acid, wherein the waste water obtained by filtering meets the emission standard and is introduced to a biochemistry processing system.

The present invention provides for a process for reducing the content of one or more residuals in aramid fibers or filaments, comprising, in this order, the steps of introducing the aramid fiber or filaments into a extraction solution adjusted to a pH ranging from of 2 to 7, adjusting the extraction solution and the aramid fibers or filaments to a temperature of to from 80 C. to 140 C., removing the aramid fibers or filaments from the extraction solution, introducing the aramid fiber or filaments into a first rinsing solution adjusted to a pH ranging from of 2 to 7, optionally comprising a detergent, adjusting the first rinsing solution and the aramid fibers and filaments to a temperature of from 70 C. to 100 C., removing the aramid fibers or filaments from the first rinsing solution.

The present invention provides for a process for reducing the content of one or more residuals in aramid fibers or filaments, comprising, in this order, the steps of introducing the aramid fiber or filaments into a extraction solution adjusted to a pH ranging from of 2 to 7, adjusting the extraction solution and the aramid fibers or filaments to a temperature of to from 80 C. to 140 C., removing the aramid fibers or filaments from the extraction solution, introducing the aramid fiber or filaments into a first rinsing solution adjusted to a pH ranging from of 2 to 7, optionally comprising a detergent, adjusting the first rinsing solution and the aramid fibers and filaments to a temperature of from 70 C. to 100 C., removing the aramid fibers or filaments from the first rinsing solution.

Provided is a method for regenerating a carbon fiber bundle from a structure having a hollow substrate, and a carbon fiber reinforced resin layer including a carbon fiber bundle that is wound around the hollow substrate, and a matrix resin, the method including a first heating process of heating the structure to decompose a part of the matrix resin, an unwinding process of unwinding an intermediate carbon fiber bundle to which decomposition residue of the matrix resin is adhering from the carbon fiber reinforced resin layer in which a part of the matrix resin is decomposed, a second heating process of heating the unwound intermediate carbon fiber bundle to decompose the decomposition residue of the matrix resin by using a tube furnace, and thereby obtaining a regenerated carbon fiber bundle, and a winding process of winding the regenerated carbon fiber bundle.

Provided is a method for regenerating a carbon fiber bundle from a structure having a hollow substrate, and a carbon fiber reinforced resin layer including a carbon fiber bundle that is wound around the hollow substrate, and a matrix resin, the method including a first heating process of heating the structure to decompose a part of the matrix resin, an unwinding process of unwinding an intermediate carbon fiber bundle to which decomposition residue of the matrix resin is adhering from the carbon fiber reinforced resin layer in which a part of the matrix resin is decomposed, a second heating process of heating the unwound intermediate carbon fiber bundle to decompose the decomposition residue of the matrix resin by using a tube furnace, and thereby obtaining a regenerated carbon fiber bundle, and a winding process of winding the regenerated carbon fiber bundle.