Recovery method of polyester cotton blended fabric

Abstract

The invention provides a polyester cotton blended fabric recycling method. Firstly, the polyester cotton blended fabric is divided into fragments; then, the fragments are placed in a reactor, a mixed aqueous solution of an acidic compound and a metal catalyst is added, the temperature is raised to 110-160 DEG C, and a reaction is conducted for 1-6 hours, so that the cotton fibers in the fragments are cracked; and then, filtering and separating to obtain the cotton powder and the polyester fibers.

Description

Technical Field

[0001] The present invention relates to a method for recycling fabrics, and more particularly to a method for recycling polyester-cotton blended fabrics. Background Art

[0002] With the improvement of people's living and consumption levels, the service life of textiles has been significantly shortened, resulting in a large amount of textile waste, among which polyester-cotton blended fabrics account for a high proportion. Therefore, how to recycle and reuse such waste textiles has become an important issue. In the prior art, for the separation method of polyester fiber and cotton blended fabrics, most of them need to use harmful substances (such as hydrochloric acid or concentrated phosphoric acid) or expensive solvents (such as NMMO) as catalysts or solvents, and the reaction must be carried out at high temperatures, which causes a greater burden on the environment or has the disadvantage of high production costs.

[0003] Based on the above, developing a method for recycling polyester-cotton blended fabrics to reduce production costs and avoid burdening the environment has become an important research topic currently needed. Summary of the Invention

[0004] The present invention provides a method for recycling polyester-cotton blended fabrics, which can effectively reduce production costs and avoid burdening the environment.

[0005] The method for recycling polyester-cotton blended fabrics of the present invention includes the following steps. First, the polyester-cotton blended fabric is cut into pieces. Then, the pieces are placed in a reactor, and an aqueous solution mixture of an acidic compound and a metal catalyst is added, and the temperature is raised to 110°C to 160°C, and the reaction is carried out for 1 hour to 6 hours to crack the cotton fibers in the pieces. Next, filtration separation is carried out to obtain cotton powder and polyester fibers.

[0006] In an embodiment of the present invention, the pressure in the reactor is 1.5 bars to 12 bars.

[0007] In an embodiment of the present invention, the acidic compound is an organic acid or an inorganic acid. The organic acids include formic acid, acetic acid, oxalic acid, tartaric acid, citric acid, malic acid or methanesulfonic acid, and the inorganic acids include hydrochloric acid, sulfuric acid or phosphoric acid.

[0008] In an embodiment of the present invention, the metal catalyst includes metal compounds of copper, nickel, cobalt, iron or zinc.

[0009] In an embodiment of the present invention, the metal catalyst includes CuCl2, Ni(NO3)2, Co(NO3)2, FeCl3 or ZnCl2.

[0010] In an embodiment of the present invention, based on the total weight of the aqueous solution mixture, the content of the acidic compound is 0.1 wt% to 10 wt%, and the content of the metal catalyst is 0.1 wt% to 5 wt%.

[0011] In one embodiment of the present invention, the solid-liquid weight ratio of the debris to the mixed aqueous solution is 1:5 to 1:50.

[0012] Based on the above, the present invention provides a method for recycling polyester-cotton blended fabrics, mainly through a hydrothermal reaction catalyzed by highly efficient circulating acid and metal catalyst to separate and recycle waste polyester-cotton blended fabrics. Through a composite formula of organic acid and metal catalyst combination, cotton can be cracked more efficiently. Therefore, the process time can be shortened and the reaction temperature can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] None DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are illustrative, and the disclosure of the present invention is not limited thereto.

[0015] In this document, a range represented by "one numerical value to another numerical value" is a schematic representation method to avoid listing all the numerical values in the range in the specification one by one. Therefore, the description of a specific numerical range covers any numerical value within the range and a smaller numerical range defined by any numerical value within the range, as if the arbitrary numerical value and the smaller numerical range are written out in the specification.

[0016] The method for recycling polyester-cotton blended fabrics of the present invention includes the following steps. First, the polyester-cotton blended fabric is divided into fragments. Then, the fragments are placed in a reactor, and a mixed aqueous solution of an acidic compound and a metal catalyst is added, and the temperature is raised to 110°C to 160°C, and the reaction is carried out for 1 hour to 6 hours to crack the cotton fibers in the fragments. Next, filtration separation is carried out to obtain cotton powder and polyester fibers.

[0017] In this embodiment, the pressure in the reactor is, for example, 1.5 bars to 12 bars, that is, the reaction is carried out in a high-pressure environment, and a mixed aqueous solution of an acidic compound and a metal catalyst is added under hydrothermal conditions and repeatedly applied to the textile fragments in a circulating reflux manner to crack the cotton fibers in the fragments. Then, filtration separation is carried out to obtain cotton powder and polyester fibers, and the catalyst is recovered for recycling.

[0018] In this embodiment, the acidic compound is an organic acid or an inorganic acid. The organic acid may include formic acid, acetic acid, oxalic acid, tartaric acid, citric acid, malic acid, or methanesulfonic acid, and the inorganic acid may include hydrochloric acid, sulfuric acid, or phosphoric acid. However, the present invention is not limited thereto. The metal catalyst may include metal compounds of copper, nickel, cobalt, iron, or zinc, such as CuCl2, Ni(NO3)2, Co(NO3)2, FeCl3, or ZnCl2. However, the present invention is not limited thereto. Based on the total weight of the mixed aqueous solution, the content of the acidic compound is, for example, 0.1 wt% to 10 wt%, and the content of the metal catalyst is, for example, 0.1 wt% to 5 wt%. The solid-liquid weight ratio of the debris to the mixed aqueous solution is, for example, 1:5 to 1:50.

[0019] Hereinafter, the method for recycling the polyester-cotton blended fabric of the present invention will be described in detail by means of experimental examples. However, the following experimental examples are not intended to limit the present invention.

[0020] Experimental Example

[0021] In order to prove that the method for recycling the polyester-cotton blended fabric proposed by the present invention can more efficiently crack the cotton, thereby shortening the process time and reducing the reaction temperature, the following experimental example is specifically made.

[0022] As shown in Table 1 below, in Comparative Example 1, only the acidic compound was used and no metal catalyst was used. Therefore, the reaction temperature was higher, the process time was longer, and the PET recovery rate was lower. In Comparative Example 2, only the metal catalyst was used and no acidic compound was used. Therefore, the reaction temperature was higher, the process time was longer, and the PET recovery rate was significantly lower. In contrast, in Examples 1 to 8, the method for recycling the polyester-cotton blended fabric of the present invention was used. Through the composite formula of the combination of the organic acid and the metal catalyst, the cotton can be more efficiently cracked. Therefore, the process time can be shortened and the reaction temperature can be reduced, and the PET recovery rate is also higher.

[0023] Table 1

[0024]

[0025]

[0026] In summary, the present invention provides a method for recycling a polyester-cotton blended fabric, mainly through a hydrothermal reaction catalyzed by a highly efficient circulating acid and a metal catalyst to separate and recycle waste polyester-cotton blended fabrics. Through the composite formula of the combination of the organic acid and the metal catalyst, the cotton can be more efficiently cracked. Therefore, the process time can be shortened and the reaction temperature can be reduced. In this way, the disadvantages of the prior art that the reaction must be carried out at a high temperature, resulting in a greater environmental burden or higher production costs, can be effectively improved.

Claims

1. A method for recycling polyester-cotton blended fabric, characterized in that: include: Cut the polyester-cotton blend fabric into pieces; Placing the fragments in a reactor, adding a mixed aqueous solution of an acidic compound and a metal catalyst, and heating the mixture to a temperature of 110° C. to 160° C., and reacting the mixture for 1 to 6 hours to cleave the cotton fibers in the fragments; and The mixture was filtered and separated to obtain cotton powder and polyester fiber.

2. The method for recycling polyester-cotton blended fabric according to claim 1, characterized in that: The pressure in the reactor is 1.5 bars to 12 bars.

3. The method for recycling polyester-cotton blended fabric according to claim 1, characterized in that: The acidic compound is an organic acid or an inorganic acid. The organic acid includes formic acid, acetic acid, oxalic acid, tartaric acid, citric acid, malic acid or methanesulfonic acid. The inorganic acid includes hydrochloric acid, sulfuric acid or phosphoric acid.

4. The method for recycling polyester-cotton blended fabric according to claim 1, characterized in that: The metal catalyst includes a metal compound of copper, nickel, cobalt, iron or zinc.

5. The method for recycling polyester-cotton blended fabric according to claim 1, characterized in that: The metal catalyst includes CuCl2, Ni(NO3)2, Co(NO3)2, FeCl3 or ZnCl2.

6. The method for recycling polyester-cotton blended fabric according to claim 1, characterized in that: Based on the total weight of the mixed aqueous solution, the content of the acidic compound is 0.1 wt % to 10 wt %, and the content of the metal catalyst is 0.1 wt % to 5 wt %.

7. The method for recycling polyester-cotton blended fabric according to claim 1, characterized in that: The solid-liquid weight ratio of the fragments to the mixed aqueous solution is 1:5 to 1:50.

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