Disposal method for waste fabric containing polyester, nylon, and dye

Patent metadata

Field	Value
Publication number	US-12410298-B2
Application number	US-202217690019-A
Country	US
Kind code	B2
Filing date	Mar 9, 2022
Priority date	Oct 21, 2021
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A disposal method for waste fabric containing polyester, nylon, and dye includes the following steps: step (a): providing a waste fabric containing polyester, nylon, and dye; and step (b): performing a first-stage treatment including acid treatment on the waste fabric to obtain a first liquid material and a first solid material. The first-stage treatment includes acid treatment with an acid liquid mixed with an oxidant. The first solid material includes recycled polyester, and/or the first liquid material includes recycled nylon or degraded nylon.

First claim

What is claimed is:

1. A disposal method for waste fabric containing polyester, nylon, and dye, comprising:
step (a): providing a waste fabric containing polyester, nylon, and dye;
step (b): performing a first-stage treatment on the waste fabric to obtain a first liquid material and a first solid material;
step (c): performing a second-stage treatment on the first liquid material to obtain a second liquid material and a second solid material;
step (d): performing a third-stage treatment on the first solid material to at least obtain a third liquid material and a third solid material; and
step (e): performing a fourth-stage treatment on the third solid material to obtain a fourth liquid material and a fourth solid material,
wherein the first-stage treatment comprises acid treatment with an acid liquid mixed with an oxidant, so as to decompose or decolorize the dye and to dissolve the nylon in the first stage treatment;
wherein the second-stage treatment comprises a dilution process;
wherein an acid concentration of the second liquid material is lower than an acid concentration of the first liquid material;
wherein the first solid material comprises recycled polyester;
wherein the first liquid material comprises recycled nylon or degraded nylon;
wherein a concentration of the oxidant used in the acid treatment of the first-stage treatment is 0.5 wt % to 10 wt %;
wherein the acid treatment in the first-stage treatment further comprises heating to 80° C. to 150° C.;
wherein based on a total amount of the nylon in the waste fabric, an amount of the nylon in the first liquid material is 75 wt % to 90 wt %, and an amount of the nylon in the first solid material is 25 wt % to 10 wt %;
wherein the third-stage treatment comprises an acid treatment;
wherein the fourth-stage treatment comprises a dilution treatment;
wherein an acid concentration of the fourth liquid material is lower than an acid concentration of the third liquid material;
wherein the third solid material comprises recycled polyester, or the fourth solid material comprises recycled nylon;
wherein the step (a), the step (b), the step (d) and the step (e) are performed N times, where N is greater than or equal to 2;
wherein the step (c) is performed M times, where M is less than or equal to N; and
wherein the acid treatment of the N-th third-stage treatment comprises performing an acid treatment with the M-th second liquid material; or
wherein the acid treatment of the N-th third-stage treatment comprises performing an acid treatment with the P-th fourth liquid, wherein P is smaller than N.

2. The disposal method for waste fabric containing polyester, nylon, and dye according to claim 1 , wherein the acid used in the acid treatment of the first-stage treatment is formic acid or acetic acid.

3. The disposal method for waste fabric containing polyester, nylon, and dye according to claim 1 , wherein the oxidant is an inorganic oxidant selected from the group consisting of hydrogen peroxide, permanganate, ozone, nitric acid, nitrate, chlorate, perchlorate, hypochlorite, perborate, dichromic acid salt, and combinations thereof.

4. The disposal method for waste fabric containing polyester, nylon, and dye according to claim 1 , wherein an acid concentration of the acid used in the acid treatment of the first-stage treatment is 20 wt % to 95 wt %.

5. The disposal method for waste fabric containing polyester, nylon, and dye according to claim 1 , wherein the acid treatment is performed at a temperature higher than a glass transition temperature of polyester.

6. The disposal method for waste fabric containing polyester, nylon, and dye according to claim 1 , wherein in step (b), a weight ratio of the waste fabric to the acid liquid mixed with the oxidant ranges from 1:8 to 1:30.

7. The disposal method for waste fabric containing polyester, nylon, and dye according to claim 1 , wherein the first-stage treatment takes 1 hour to 9 hours.

8. The disposal method for waste fabric containing polyester, nylon, and dye according to claim 1 , wherein the recycled polyester has an L value of 75% or more, an a* value ranges from −4 to +4, and a b* value ranges from −8 to +8.

Assignees

• Nan Ya Plastics Corp

Inventors

• Liao Te-Chao
• Chuang Jung-Jen
• Huang zhang-jian
• Wong Tzu-Huan

Classifications

• Y02W30/62

  Plastics recycling; Rubber recycling · CPC title

• B29B2017/0203

  Separating plastics from plastics · CPC title

• D06L4/13

  using inorganic agents · CPC title

• D06P5/132

  with oxidants · CPC title

• Y02W30/66

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