The present disclosure relates to methods and systems for recovering and repolymerizing textile fibers. Textile fibers, such as those containing cellulose or elastomers, can undergo multiple rounds of recovery and regeneration. During the regeneration process, the textile fibers are isolated from non-desired material, repolymerized or reformed, and then extruded to form a second set of textile fibers. The degree of polymerization of the textile fiber decreases with each regeneration cycle. Regeneration and production can be repeated any appropriate number of times until the regenerated textile fibers do not have the necessary or appropriate degree of polymerization for textile production.

Methods and systems of the present invention use mixed textile feedstock, which may include post-consumer waste garments, scrap fabric and/or other textile materials as a raw feed material to produce isolated cellulose and other isolated molecules having desirable properties that can be used and be used in the textile and apparel industries, and in other industries. A multi-stage process is provided, in which mixed textile feed material is subjected to one or more pretreatment stages, followed by at least two pulping treatments for isolating cellulose molecules and other molecular constituents, such as polyester. The isolated cellulose and polyester molecules may be used in a variety of downstream applications. In one application, isolated cellulose and polyester molecules are extruded to provide regenerated cellulose fibers and regenerated polyester fibers having desirable (and selectable) properties that are usable in various industrial applications, including textile production.

The purpose of the invention is to provide a porous hollow-fiber membrane containing a regenerated cellulose and having an elastic limit pressure of 200 kPa or more.

A virus removal membrane includes cellulose, and a primary-side surface through which the protein-containing solution is to be applied and a secondary-side surface from which a permeate that has permeated the virus removal membrane is to be flowed, wherein a bubble point is 0.5 MPa or more and 1.0 MPa or less; and when a solution containing gold colloids having a diameter of 30 nm is applied through the primary-side surface to the virus removal membrane to allow the virus removal membrane to capture the gold colloids for measurement of brightness in a cross section of the virus removal membrane, a value obtained by dividing a standard deviation of a value of an area of a spectrum of variation in the brightness by an average of the value of the area of the spectrum of variation in the brightness is 0.01 or more and 0.30 or less.

A virus removal membrane includes cellulose, and a primary-side surface through which the protein-containing solution is to be applied and a secondary-side surface from which a permeate that has permeated the virus removal membrane is to be flowed, wherein a bubble point is 0.5 MPa or more and 1.0 MPa or less; and when a solution containing gold colloids having a diameter of 30 nm is applied through the primary-side surface to the virus removal membrane to allow the virus removal membrane to capture the gold colloids for measurement of brightness in a cross section of the virus removal membrane, a value obtained by dividing a standard deviation of a value of an area of a spectrum of variation in the brightness by an average of the value of the area of the spectrum of variation in the brightness is 0.01 or more and 0.30 or less.

Methods and systems of the present invention use mixed textile feedstock, which may include post-consumer waste garments, scrap fabric and/or other textile materials as a raw feed material to produce isolated cellulose and other isolated molecules having desirable properties that can be used and be used in the textile and apparel industries, and in other industries. A multi-stage process is provided, in which mixed textile feed material is subjected to one or more pretreatment stages, followed by at least two pulping treatments for isolating cellulose molecules and other molecular constituents, such as polyester. The isolated cellulose and polyester molecules may be used in a variety of downstream applications. In one application, isolated cellulose and polyester molecules are extruded to provide regenerated cellulose fibers and regenerated polyester fibers having desirable (and selectable) properties that are usable in various industrial applications, including textile production.

Methods and systems of the present invention use mixed textile feedstock, which may include post-consumer waste garments, scrap fabric and/or other textile materials as a raw feed material to produce isolated cellulose and other isolated molecules having desirable properties that can be used and be used in the textile and apparel industries, and in other industries. A multi-stage process is provided, in which mixed textile feed material is subjected to one or more pretreatment stages, followed by at least two pulping treatments for isolating cellulose molecules and other molecular constituents, such as polyester. The isolated cellulose and polyester molecules may be used in a variety of downstream applications. In one application, isolated cellulose and polyester molecules are extruded to provide regenerated cellulose fibers and regenerated polyester fibers having desirable (and selectable) properties that are usable in various industrial applications, including textile production.

The present invention provides recycled cellulose-based fibers dimensionally stabilized by the reduction of shrinkage after washing in water or the like. The recycled cellulose fibers have an adsorbate on a surface thereof, in which the adsorbate contains cellulose nanofibers.

The present invention provides recycled cellulose-based fibers dimensionally stabilized by the reduction of shrinkage after washing in water or the like. The recycled cellulose fibers have an adsorbate on a surface thereof, in which the adsorbate contains cellulose nanofibers.

Provided are cellulose microfibers (fibrous cellulose) that can be used in a general-purpose manner for a variety of applications and that have a uniform fiber diameter distribution and a low proportion of both cellulose nanofibers and coarse structures, a composition containing said cellulose fibers, and a porous body composed of said cellulose fibers. The present invention relates to cellulose fibers in which the average fiber diameter in a dry state is 0.3-3.0 um as observed using an electron microscope, the proportion of fibers having a fiber diameter of less than 0.1 um is 5% or less, and the proportion of coarse structures as indicated by the proportion of fibers having a wet fiber diameter of 20 um or greater measured through automatic optical analysis is 3.0% or less. The present invention also relates to a composition containing said cellulose fibers, and a porous body composed of said cellulose fibers.