Method for recycling polyester cotton blended fabric

Abstract

To provide a method for recycling a polyester cotton blended fabric.SOLUTION: First, a polyester cotton blended fabric is divided into pieces. The pieces are then placed in a reactor, and a mixed aqueous solution of an acidic compound and a metal catalyst is added. A temperature is raised to 110°C to 160°C, and a reaction is carried out for 1 to 6 hours to decompose cotton fibers in the pieces. Then, the mixture is filtered and separated to obtain cotton powder and polyester fibers.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] With the improvement of people's living standards and consumption levels, the service life of textiles has been significantly shortened, resulting in a large amount of textile waste. Here, polyester-cotton blended textiles account for a high proportion. Therefore, how to recycle and reuse this kind of waste textiles has become an important issue. In the separation method of polyester fiber and cotton blended textiles in the prior art, in many cases, it is necessary to use harmful substances (such as hydrochloric acid and concentrated phosphoric acid) or expensive solvents (such as NMMO) as catalysts and solvents, and it is necessary to react at high temperatures. Therefore, there are drawbacks such as a large environmental load or high production costs.

[0003] Based on the above, developing a method for recycling polyester-cotton blended textiles that can reduce production costs and avoid environmental loads is an important issue that currently requires research.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a method for recycling polyester-cotton blended textiles that can effectively reduce production costs and avoid environmental loads.

Means for Solving the Problems

[0005] The method for recycling polyester-cotton blended textiles of the present invention includes the following steps. First, the polyester-cotton blended textile is divided 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 from 110°C to 160°C and reacted for 1 hour to 6 hours to decompose the cotton fibers in the pieces. Next, filtration separation is performed to obtain cotton powder and polyester fibers.

[0006] In one embodiment of the present invention, the pressure in the reactor is from 1.5 bar to 12 bar.

[0007] In one embodiment of the present invention, 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, and the inorganic acid includes hydrochloric acid, sulfuric acid or phosphoric acid.

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

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

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

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

Advantages of the Invention

[0012] Based on the above, the present invention mainly provides a method for recycling polyester-cotton blended textiles, which separates and recycles waste polyester-cotton blended textiles through a highly efficient circulating acid and metal catalyst-catalyzed hydrothermal reaction. Through the composite formulation with the combination of an organic acid and a metal catalyst, cotton can be decomposed more efficiently. Therefore, the manufacturing process time can be shortened and the reaction temperature can be lowered.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are illustrative, and the present invention is not limited thereto.

[0014] In addition, in this specification, a range expressed as "from one value to another value" is a summary expression to avoid listing all the values within the range one by one in the specification. Therefore, the description of a specific numerical range shall be deemed to include any numerical value within the said numerical range and a smaller numerical range defined by any numerical value within the said numerical range, as if any numerical value and a smaller numerical value than that were described in the description of the specific numerical range in the specification.

[0015] The recycling method of the polyester-cotton blended fabric of the present invention includes the following steps. First, the polyester-cotton blended fabric is divided into pieces. Then, the pieces are placed in a reactor, an aqueous mixed solution of an acidic compound and a metal catalyst is added, the temperature is raised from 110°C to 160°C, and the reaction is carried out for 1 hour to 6 hours to decompose the cotton fibers in the pieces. Next, filtration separation is performed to obtain cotton powder and polyester fibers.

[0016] In this embodiment, the pressure inside the reactor is, for example, from 1.5 bar to 12 bar. That is, the reaction is carried out under a high-pressure environment, an aqueous mixed solution of an acidic compound and a metal catalyst is added under hydrothermal conditions, and it is repeatedly applied in a countercurrent manner circulated to the pieces of the fabric to decompose the cotton fibers in the pieces. Then, filtration separation is performed to obtain cotton powder and polyester fibers, and the catalyst is recycled and reused.

[0017] 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, but the present invention is not limited thereto. The metal catalyst may include a metal compound of copper, nickel, cobalt, iron or zinc, and may include, for example, 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 aqueous mixed solution, the content of the acidic compound is, for example, from 0.1 wt% to 10 wt%, and the content of the metal catalyst is, for example, from 0.1 wt% to 5 wt%. The solid-liquid weight ratio of the pieces to the aqueous mixed solution is, for example, from 1:5 to 1:50.

[0018] Hereinafter, through experimental examples, the recycling method of the polyester-cotton blended fabric of the present invention described above will be described in detail. However, the following experimental examples do not limit the present invention.

[0019] Experimental Example

[0020] In order to prove that the recycling method of the polyester-cotton blended fabric proposed by the present invention can decompose cotton more efficiently, thereby shortening the manufacturing process time and lowering the reaction temperature, experimental examples are shown below.

[0021] As shown in Table 1 below, in Comparative Example 1, only an acidic compound was used and no metal catalyst was used. Therefore, the reaction temperature was high, the manufacturing process time was long, and the PET recovery rate was low. In Comparative Example 2, only a metal catalyst was used and no acidic compound was used. Therefore, the reaction temperature was high, the manufacturing process time was long, and the PET recovery rate was significantly low. On the other hand, in Examples 1 to 8, the recycling method of the polyester-cotton blended fabric of the present invention was used, and by the combined compounding of an organic acid and a metal catalyst, cotton could be decomposed more efficiently. Therefore, the manufacturing process time could be shortened, the reaction temperature could be lowered, and the PET recovery rate was also high.

[0022] [Table 1]

[0023] To sum up, the present invention provides a recycling method for polyester-cotton blended fabrics, which mainly separates and recycles waste polyester-cotton blended fabrics through a highly efficient circulating acid and metal catalyst catalytic hydrothermal reaction. By the combined compounding of an organic acid and a metal catalyst, cotton can be decomposed more efficiently. Therefore, the manufacturing process time can be shortened and the reaction temperature can be lowered. In this way, the disadvantages that in the prior art, the reaction must be carried out at a high temperature, resulting in a large environmental load or high production costs, can be effectively improved.

Industrial Applicability

[0024] The recycling method of the polyester-cotton blended fabric of the present invention can be applied to the recycling and reuse of waste textiles.

Claims

1. Dividing a polyester-cotton blended fabric into pieces; Placing the pieces in a reactor, adding an aqueous mixed solution of an acidic compound and a metal catalyst, heating the temperature to 110°C to 160°C, and reacting for 1 hour to 6 hours to decompose the cotton fibers in the pieces; Performing filtration separation to obtain cotton powder and polyester fibers; A recycling method for a polyester-cotton blended fabric, comprising the above steps.

2. The pressure inside the reactor is 1.5 bar to 12 bar. The recycling method for a polyester-cotton blended fabric according to Claim 1.

3. 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. The recycling method for a polyester-cotton blended fabric according to Claim 1.

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

5. The metal catalyst is CuCl ２ , Ni(NO ３ ), ２ , Co(NO ３ ), ２ , FeCl ３ or ZnCl ２ and contains The recycling method for a polyester-cotton blended fabric according to Claim 1.

6. Based on the total weight of the aqueous mixed 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%. The recycling method for a polyester-cotton blended fabric according to Claim 1.

7. The solid-liquid weight ratio of the pieces to the aqueous mixed solution is 1:5 to 1:

50. The recycling method for a polyester-cotton blended fabric according to Claim 1.

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