Method for processing waste fabric containing polyester and cotton fibers

Patent metadata

Field	Value
Publication number	US-12466933-B2
Application number	US-202217874263-A
Country	US
Kind code	B2
Filing date	Jul 26, 2022
Priority date	Oct 25, 2021
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A method for processing a waste fabric containing polyester and cotton fibers includes the following steps. The first step is providing a plurality of fabric scraps each containing polyester fibers and cotton fibers. The next step is allowing an acid catalyst aqueous solution to repeatedly contact and react with the fabric scraps at 130° C. to 160° C. in a circulation and backflow manner, so as to separate the cotton fibers from each of the fabric scraps. The last step is recycling the reacted acid catalyst aqueous solution and fabric scraps.

First claim

What is claimed is:

1 . A method for processing a waste fabric containing polyester and cotton fibers, comprising:
providing a plurality of fabric scraps each containing polyester fibers and cotton fibers; having an acid catalyst aqueous solution repeatedly contact and react with the fabric scraps at 130° C. to 160° C. in a circulation and backflow manner, so as to separate the cotton fibers from each of the fabric scraps,
wherein a contact frequency of the acid catalyst aqueous solution with the fabric scraps is 3 to 4 times per minute, and a solid to liquid ratio of the fabric scraps to the acid catalyst aqueous solution is 1:5-25; and
recycling the reacted acid catalyst aqueous solution and fabric scraps.

2 . The method according to claim 1 , wherein the fabric scraps are obtained by fragmentizing a waste fabric or processed products thereof.

3 . The method according to claim 1 , wherein the acid catalyst aqueous solution includes 0.1 wt % to 10 wt % of at least one acid catalyst.

4 . The method according to claim 3 , wherein the content of the at least one acid catalyst in the acid catalyst aqueous solution is 3 wt % to 5 wt %.

5 . The method according to claim 3 , wherein the at least one acid catalyst is an organic acid, an organic acid anhydride, a Lewis acid, or any combination thereof.

6 . The method according to claim 5 , wherein the organic acid is oxalic acid, the organic acid anhydride is acetic anhydride, and the Lewis acid is zinc chloride.

7 . The method according to claim 1 , wherein the step of having the acid catalyst aqueous solution repeatedly contact and react with the fabric scraps is carried out for 1 hour to 5 hours.

8 . The method according to claim 7 , wherein in the step of having the acid catalyst aqueous solution repeatedly contact and react with the fabric scraps, the cotton fibers of each of the fabric scraps are split and dissolved into the reacted acid catalyst aqueous solution.

9 . The method according to claim 1 , further comprising: recycling the cotton fibers from the reacted acid catalyst aqueous solution.

10 . The method according to claim 1 , further comprising: performing degradation and repolymerization processes on the polyester fibers of each of the reacted fabric scraps, so as to produce recycled polyester pellets.

Assignees

• Nan Ya Plastics Corp

Inventors

• Liao Te-Chao
• Chuang Jung-Jen
• Su Chung-Chi
• Huang zhang-jian

Classifications

• C08J2367/00

  Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers · CPC title

• D10B2201/02

  Cotton · CPC title

• D10B2331/04

  polyesters, e.g. polyethylene terephthalate [PET] · CPC title

• D01G11/00

  Disintegrating fibre-containing articles to obtain fibres for re-use · CPC title

• C08J2367/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) · CPC title