Recycling method of polyester / acrylic fiber blended material

Abstract

The invention provides a recovery method of a polyester / acrylic fiber blended material. The recovery method comprises the following steps: stirring the following components to obtain a composite solvent: 65-85% of N-methyl pyrrolidone, 10-30% of ethylene glycol monomethyl ether, 0.5-5.0% of sodium pyrosulfite and 0.1-0.3% of vitamin E; adding the terylene / acrylic fiber blended material into a composite solvent, heating and stirring to dissolve acrylic fibers in the terylene / acrylic fiber blended material and suspend terylene in the solution without dissolving to form a solid-liquid mixture; the solid-liquid mixture is filtered, polyester filter residues and filtrate containing acrylic fibers are obtained, and polyester in the filter residues is regenerated polyester; and distilling the filtrate containing the acrylic fibers, and separating the composite solvent from the acrylic fibers to obtain regenerated acrylic fibers. Acrylic fibers in the polyester / acrylic fiber blended material are dissolved through the composite solvent, and then the regenerated polyester fibers and the regenerated acrylic fibers are obtained through filtration and distillation, so that the polyester fibers and the acrylic fibers can be efficiently recycled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of recycling of blended materials, and particularly relates to a recycling method of polyester / acrylic blended material. BACKGROUND

[0002] Polyester (polyethylene terephthalate, PET) and acrylic (polyacrylonitrile, PAN) are widely used in the fields of clothing, home textiles, industrial textiles, etc. due to their excellent performance (such as the wear resistance and wrinkle resistance of polyester, and the warmth retention and sun resistance of acrylic). The blended fabric of polyester and acrylic accounts for an increasing proportion in the market.

[0003] However, with the increasing speed of iteration of textile products, a large amount of waste polyester / acrylic blended material faces the problem of recycling. Since the chemical structures of the two polymers are similar and the physical properties (such as melting point and density) are slightly different, traditional physical separation methods (such as density separation and melting separation) cannot effectively separate them. The existing chemical separation methods have many defects. Most of the methods use a single strong polar solvent (such as dimethylformamide and dimethyl sulfoxide) to dissolve acrylic, but such solvents also have a certain swelling effect on polyester, resulting in low purity (usually less than 90%) of acrylic after separation, and high energy consumption for solvent recovery. Some processes use strong acid (such as concentrated nitric acid) or strong base (such as sodium hydroxide) as a decomposing agent, which can destroy one component but will cause the degradation of the other component, making it impossible to achieve "two-way recycling", and generating a large amount of acidic / alkaline wastewater, which is high in processing cost. SUMMARY

[0004] The present application aims to provide a recycling method of polyester / acrylic blended material, which solves the problems of low product purity or inability to achieve two-way recycling in the prior art.

[0005] To achieve one of the above-mentioned purposes, an embodiment of the present application provides a recycling method of polyester / acrylic blended material, comprising the following steps: Preparation of a composite solvent: the components of the composite solvent include, in terms of mass percentage, N-methylpyrrolidone: 65-85%, ethylene glycol monomethyl ether: 10-30%, sodium pyrosulfite: 0.5-5.0%, and vitamin E: 0.1-0.3%. The above components are stirred to obtain the composite solvent; Dissolution: the polyester / acrylic blended material is added to the composite solvent and heated and stirred, so that the acrylic in the polyester / acrylic blended material is dissolved, and the polyester is not dissolved but suspended in the solution, forming a solid-liquid mixture; Solid-liquid separation: the solid-liquid mixture obtained after dissolution is filtered to obtain polyester filter residue and acrylic-containing filtrate, and the polyester in the filter residue is regenerated polyester; Distillation separation: the acrylic-containing filtrate is distilled to separate the composite solvent and the acrylic, obtaining regenerated acrylic.

[0006] As a further improvement of the embodiment of the present application, in the dissolving step, the polyester / acrylic blended material is dissolved at a temperature of 80-100°C for 1-2h.

[0007] As a further improvement of the embodiment of the present application, in the dissolving step, the stirring rate is 200-300rpm.

[0008] As a further improvement of the embodiment of the present application, in the dissolving step, the mass ratio of the polyester / acrylic blended material to the composite solvent is 1: (8-12).

[0009] As a further improvement of the embodiment of the present application, in the solid-liquid separation step, the solid-liquid mixture is subjected to pressure filtration, the pressure filtration pressure is controlled to be 0.3-0.5MPa, and the filtration precision is 0.1-0.2μm.

[0010] As a further improvement of the embodiment of the present application, in the solid-liquid separation step, the polyester filter residue is washed with deionized water and then dried at a temperature of 90-100°C for 3-4h.

[0011] As a further improvement of the embodiment of the present application, in the distillation separation step, the filtrate containing the acrylic is subjected to reduced pressure distillation, the pressure is controlled to be 0.08-0.09MPa, and the reduced pressure distillation is carried out at 90-100°C.

[0012] As a further improvement of the embodiment of the present application, before the dissolving step, a pretreatment step is further included, in the pretreatment step, the polyester / acrylic blended material is crushed into polyester / acrylic blended particles with a particle size of 2-5mm, and then the particles are added into a sodium carbonate solution with a concentration of 5-8%, stirred at a temperature of 60-70°C, and impurities are removed.

[0013] As a further improvement of the embodiment of the present application, the polyester / acrylic blended particles removed of impurities by the sodium carbonate solution are washed with deionized water and then dried at 80-90°C for 2-3h.

[0014] As a further improvement of the embodiment of the present application, the recovery rate of the polyester in the polyester / acrylic blended material is ≥97%, and the purity is ≥95%; the recovery rate of the acrylic is ≥95%, and the purity is ≥95%.

[0015] The one or more technical solutions provided by the present application have at least the following technical effects or advantages: In the polyester / acrylic blended material recovery method provided by the present application, a composite solvent is innovatively provided, which only dissolves the acrylic, does not dissolve / swell / degrade the polyester, and after the dissolving is completed, the polyester and the acrylic are separated by filtration, the process steps are simple, the equipment used can all be mature equipment, and the scale production is easy to realize. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0017] The application provides a recycling method of polyester / acrylic blended material, comprising the following steps: Preparation of the composite solvent: the components of the composite solvent include, in terms of mass percentage, N-methyl pyrrolidone: 65-85%, ethylene glycol monomethyl ether: 10-30%, sodium metabisulfite: 0.5-5%, and vitamin E: 0.1-0.3%. The components are stirred to obtain the composite solvent; Dissolution: the polyester / acrylic blended material is added into the composite solvent and heated and stirred, so that the acrylic in the polyester / acrylic blended material is dissolved, the polyester is not dissolved but suspended in the solution, and a solid-liquid mixture is formed; Solid-liquid separation: the solid-liquid mixture obtained after dissolution is filtered to obtain polyester filter residue and acrylic-containing filtrate, and the polyester in the filter residue is regenerated polyester; Distillation separation: the acrylic-containing filtrate is distilled to separate the composite solvent and the acrylic, and regenerated acrylic is obtained.

[0018] In the composite solvent provided by the application, N-methyl pyrrolidone (NMP) accounts for a large proportion and serves as the main solvent, which has strong dissolving capacity for acrylic and no swelling effect on polyester, so that part of the polyester that is swelled during the filtration is avoided to be left in the filtrate, the boiling point of the polyester is relatively high, so that the polyester cannot be evaporated together with the composite solvent during the distillation but is left in the distillation device together with the acrylic, and the purity of the acrylic is reduced.

[0019] In addition, the NMP can be recovered after the distillation in the distillation separation step and returned to the dissolution step for dissolving the polyester / acrylic blended material.

[0020] The ethylene glycol monomethyl ether as a cosolvent can reduce the viscosity of the main solvent NMP and improve the dissolving rate of the acrylic. The sodium metabisulfite as a stabilizer can inhibit the oxidative degradation of the polyacrylonitrile chain during the dissolution of the acrylic, protect the molecular structure, and make the molecular weight retention rate of the regenerated acrylic high. The vitamin E as an antioxidant can prevent the thermal oxidative aging of the polyester during the heating process. The NMP, the ethylene glycol monomethyl ether, the sodium metabisulfite, and the vitamin E are stirred and mixed for 15-20 min at room temperature to obtain the uniform composite solvent.

[0021] The composite solvent provided by the application can make the polyester not be dissolved / swelled and keep a solid state, so that the polyester can be filtered out in the solid-liquid separation step, and the polyester in the filter residue is the regenerated polyester.

[0022] Furthermore, under the action of the composite solvent, the polyester in the polyester / acrylic blend material will not be affected by thermal oxidative aging during heating and dissolution, thus affecting the purity of the recycled polyester. While dissolving the acrylic fiber, the composite solvent also avoids the oxidative degradation of the acrylic fiber, so that the molecular weight of the recycled acrylic fiber can still maintain the molecular weight of the acrylic fiber in the original polyester / acrylic blend material.

[0023] In one embodiment of this application, during the dissolution step, the polyester / acrylic blend material is dissolved at a temperature of 80-100°C for 1-2 hours. Heating can increase the dissolution rate of acrylic fibers, allowing the acrylic fibers in the polyester / acrylic blend material to dissolve completely in a shorter time. At the same time, the temperature of 80-100°C can also prevent the polyester from undergoing thermo-oxidative aging, thus avoiding oxidative degradation of the acrylic fibers and reducing their molecular weight.

[0024] The preferred method is to use a constant temperature water bath for heating, which can ensure the accuracy of the temperature of the composite solvent and the polyester / acrylic blended material immersed in it, and also ensure that the overall temperature is uniform and stable.

[0025] Furthermore, during the dissolution step, the stirring rate is 200-300 rpm. Stirring ensures that the polyester / acrylic blended material is fully dispersed in the composite solvent, allowing the acrylic fiber to come into full contact with each component of the composite solvent, further improving the dissolution rate and the stability of the properties of the polyester and acrylic fibers.

[0026] In one embodiment of this application, during the dissolution step, the mass ratio of the polyester / acrylic blend material to the composite solvent is 1:(8~12). This ensures that the acrylic fiber can be dissolved quickly and efficiently, and avoids increased energy consumption due to excessive distillation time caused by too much composite solvent during distillation separation.

[0027] In one embodiment of this application, in the solid-liquid separation step, the solid-liquid mixture is subjected to pressure filtration, with the filtration pressure controlled at 0.3~0.5MPa and the filtration accuracy at 0.1~0.2μm. For example, a plate and frame filter press is used for pressure filtration.

[0028] Since only polyester remained undissolved in the solid-liquid mixture, the filter residue after solid-liquid separation was polyester, and the filtrate, in addition to acrylic fiber, also contained NMP, ethylene glycol monomethyl ether, sodium metabisulfite, and vitamin E from the composite solvent.

[0029] Pressure filtration can increase the filtration rate, quickly filtering out the acrylic fibers dissolved in the composite solvent, as well as the various components in the composite solvent; it can also reduce the content of composite solvent in the polyester filter residue, thereby reducing the loss of composite solvent.

[0030] In one embodiment of this application, in the solid-liquid separation step, the polyester filter residue is rinsed with deionized water and then dried at a temperature of 90~100°C for 3~4 hours.

[0031] Although only polyester is in the filter residue after filtration, the surface of the polyester still has residual complex solvent and dissolved acrylic, so the polyester is washed with deionized water for 2-3 times to remove the surface complex solvent and acrylic, and then dried to obtain regenerated polyester solid. The dried polyester can be directly used for melt spinning or injection molding.

[0032] Since NMP is a low-toxicity substance, and since the filter pressing used in the solid-liquid separation step, the content of NMP remaining on the surface of the polyester is very small, the waste liquid generated when washing the polyester is less, and the toxicity is lower, and the waste liquid treatment cost is lower.

[0033] In an embodiment of the present application, in the distillation separation step, the filtrate containing acrylic is subjected to vacuum distillation, and the pressure is controlled at 0.08-0.09 MPa, and the vacuum distillation is carried out at 90-100°C.

[0034] By vacuum distillation, the boiling point of the complex solvent can be reduced, so that the distillation process is carried out at a temperature lower than the normal pressure boiling point, which can effectively avoid the side reactions such as decomposition or oxidation of acrylic caused by high temperature, improve the chemical stability and final quality of the product acrylic, and also greatly reduce the energy consumption required in the heating process. Preferably, a thin film evaporator is used for vacuum distillation.

[0035] The distillate of vacuum distillation is NMP and ethylene glycol monomethyl ether, and the recovery rate of NMP is ≥98%, and the recovery rate of ethylene glycol monomethyl ether is ≥97%.

[0036] In an embodiment of the present application, a pretreatment step is further included before the dissolution step, in which the polyester / acrylic blended material is crushed into polyester / acrylic blended particles with a particle size of 2-5 mm, and then the particles are added to a sodium carbonate solution with a concentration of 5-8%, and stirred at a temperature of 60-70°C to remove impurities.

[0037] During the crushing process of the polyester / acrylic blended material, not only the material is crushed into small pieces, but also the polyester / acrylic blended material forms particles during repeated friction. In the present application, the polyester / acrylic blended material can be crushed into particles by, for example, a high-speed pulverizer, which increases the specific surface area of the polyester / acrylic blended material and improves the dissolution efficiency during dissolution. The particles are stirred in the sodium carbonate solution for 30-40 min to remove impurities such as oil stains and dyes on the surface of the polyester / acrylic blended material, so that the polyester / acrylic before dissolution is free of other impurities, thereby further improving the purity of the regenerated polyester and regenerated acrylic.

[0038] Further, the polyester / acrylic blended particles removed by sodium carbonate solution are rinsed with deionized water, and then dried at 80-90°C for 2-3h. The surface of the polyester / acrylic blended material is washed with sodium carbonate solution until the washing liquid after rinsing with deionized water is neutral (pH is 6.5-7.5), ensuring that the sodium carbonate is cleaned and new impurities are not introduced.

[0039] After the foregoing pretreatment, dissolution, solid-liquid separation, and distillation separation steps, high-purity regenerated polyester and regenerated acrylic are obtained from the polyester / acrylic blended material, the recovery rate of the polyester is ≥97%, and the purity is ≥95%; the recovery rate of the acrylic is ≥95%, and the purity is ≥95%. The molecular weight retention rate of the regenerated polyester is ≥92%, and the breaking strength is ≥2.8 cN / dtex; the molecular weight retention rate of the regenerated acrylic is ≥90%, and the breaking elongation is ≥25%, which can be used for high-value-added regenerated products.

[0040] Moreover, the recovery rate of the composite solvent in the present application after the distillation separation step is ≥90%, and only the deionized water cleaning process produces wastewater in the whole process, and the wastewater discharge is reduced by more than 80% compared with the prior art.

[0041] The technical solutions of the present application will be further described below in conjunction with some specific examples.

[0042] Example 1 Pretreatment: 1000g of "polyester 50% + acrylic 50%" blended material is crushed to 3mm particles, 20L of 7% sodium carbonate solution is stirred at 65°C for 35 minutes, and after washing to neutral, 85°C vacuum drying for 2.5 hours, obtaining 980g of dry polyester / acrylic blended particles (impurity removal rate 2%).

[0043] Composite solvent preparation: mix NMP 75%, ethylene glycol monomethyl ether 24%, sodium metabisulfite 0.8%, and vitamin E 0.2% according to the mass ratio, and the total mass is 1000g, wherein: NMP 750g, ethylene glycol monomethyl ether 240g, sodium metabisulfite 8g, and vitamin E 2g, stir for 20 minutes until uniform.

[0044] Dissolution: 100g of pretreated polyester / acrylic blended particles are added to the container according to the solid-liquid ratio of 1:10, and 1000g of composite solvent is added accordingly, and stirred at 250rpm in a 90°C constant temperature water bath for 1.5 hours.

[0045] Solid-liquid separation: filter with a plate and frame filter press with a filtration precision of 0.15μm under a pressure of 0.4MPa, obtaining 50.2g of polyester filter residue and 1045g of filtrate containing acrylic.

[0046] Distillation separation: the filter residue was washed with water and then vacuum dried at 95℃ for 3.5 hours to obtain 49.8g of regenerated polyester; the filtrate containing acrylic fiber was distilled under reduced pressure at 95℃ and 0.085MPa, 979g of solvent was recovered (recovery rate 97.9%), and 48.5g of regenerated acrylic fiber was obtained after drying the residual polymer.

[0047] The purity of the regenerated polyester was 97.2% and the purity of the regenerated acrylic fiber was 96.1% as detected by high performance liquid chromatography (HPLC).

[0048] The recovery rate of polyester was 99.6% and the recovery rate of acrylic fiber was 97% as calculated.

[0049] Example 2 Pretreatment: 1000g of “polyester 50% + acrylic fiber 50%” blended material was crushed into 2mm particles, stirred in 25L of 5% sodium carbonate solution at 60℃ for 40 minutes, washed with water until neutral, and then vacuum dried at 80℃ for 3 hours to obtain 985g of dry polyester / acrylic fiber blended particles (impurity removal rate 1.5%).

[0050] Composite solvent preparation: 700g of NMP, 290g of ethylene glycol monomethyl ether, 9g of sodium metabisulfite, and 1g of vitamin E were mixed to obtain a total mass of 1000g, and stirred for 15 minutes until uniform.

[0051] Dissolution: 100g of pretreated polyester / acrylic fiber blended particles were added to a container according to a solid-liquid ratio of 1:8, and 800g of composite solvent was added accordingly, and stirred at 200rpm in a 80℃ constant temperature water bath for 2 hours.

[0052] Solid-liquid separation: the filter residue was washed with water and then vacuum dried at 95℃ for 3.5 hours to obtain 49.8g of regenerated polyester; the filtrate containing acrylic fiber was distilled under reduced pressure at 95℃ and 0.085MPa, 979g of solvent was recovered (recovery rate 97.9%), and 48.5g of regenerated acrylic fiber was obtained after drying the residual polymer.

[0053] Distillation separation: the filter residue was washed with water and then vacuum dried at 95℃ for 3.5 hours to obtain 49.8g of regenerated polyester; the filtrate containing acrylic fiber was distilled under reduced pressure at 95℃ and 0.085MPa, 979g of solvent was recovered (recovery rate 97.9%), and 48.5g of regenerated acrylic fiber was obtained after drying the residual polymer.

[0054] The purity of the regenerated polyester was 97.2% and the purity of the regenerated acrylic fiber was 96.1% as detected by high performance liquid chromatography (HPLC).

[0055] The recovery rate of polyester was 99.6% and the recovery rate of acrylic fiber was 97% as calculated.

[0056] Example 3 Pre-treatment: 1000g of blended material of "polyester 30% + acrylic 70%" was pulverized into 5mm particles, stirred in 8% sodium carbonate solution at 70°C for 30 minutes, washed to neutral, and then dried at 90°C for 2 hours to obtain 960g of dry polyester / acrylic blended particles (impurity removal rate 4%).

[0057] Composite solvent preparation: NMP 80%, ethylene glycol monomethyl ether 19%, sodium metabisulfite 0.7%, and vitamin E 0.3% were mixed in a mass ratio of 1500g, wherein: NMP 1200g, ethylene glycol monomethyl ether 285g, sodium metabisulfite 10.5g, and vitamin E 4.5g, and stirred for 18 minutes until uniform.

[0058] Dissolution: 100g of blended particles were added to the container in a solid-liquid ratio of 1:12, corresponding to the addition of 1200g of composite solvent, and stirred at 300rpm in a 100°C constant temperature water bath for 1 hour.

[0059] Solid-liquid separation: filtered with a plate and frame filter press with a filtration precision of 0.2μm at a pressure of 0.5MPa to obtain 30.3g of polyester filter residue and 1265g of acrylic-containing filtrate.

[0060] Distillation separation: the polyester filter residue was washed with water and dried at 100°C for 3 hours to obtain 29.2g of regenerated polyester; the acrylic-containing filtrate was distilled under reduced pressure at 0.09MPa and 100°C to recover 1176g of solvent (recovery rate 98%), and the residual polymer was dried to obtain 67.8g of regenerated acrylic.

[0061] The purity of the regenerated polyester was 97.8% and the purity of the regenerated acrylic was 95.8% as detected by high performance liquid chromatography (HPLC).

[0062] The polyester recovery rate was 97.3% and the acrylic recovery rate was 96.9% as calculated.

[0063] Example 4 Pre-treatment: 1000g of blended material of "polyester 70% + acrylic 30%" was pulverized into 4mm particles, stirred in 6% sodium carbonate solution at 65°C for 35 minutes, washed to neutral, and then dried at 85°C for 2.5 hours to obtain 985g of dry polyester / acrylic blended particles (impurity removal rate 1.5%).

[0064] Composite solvent preparation: NMP 75%, ethylene glycol monomethyl ether 24%, sodium metabisulfite 0.9%, and vitamin E 0.1% were mixed in a mass ratio of 1500g, wherein: NMP 1125g, ethylene glycol monomethyl ether 360g, sodium metabisulfite 13.5g, and vitamin E 1.5g, and stirred for 20 minutes until uniform.

[0065] Dissolution: 100 g of blended particles were added into a container with a solid-liquid ratio of 1:11, corresponding to 1100 g of composite solvent, and stirred at 280 rpm in a constant temperature water bath at 95℃ for 1.2 hours.

[0066] Solid-liquid separation: filtration was performed using a plate-and-frame filter press with a filtration accuracy of 0.15 μm under a pressure of 0.45 MPa, obtaining 70.2 g of polyester filter residue and 1125 g of filtrate containing acrylic.

[0067] Distillation separation: after water washing, the filter residue was dried at 95℃ under vacuum for 3.5 hours, obtaining 69.8 g of regenerated polyester; the filtrate containing acrylic was distilled under reduced pressure at 0.085 MPa and 95℃, recovering 1069 g of solvent (recovery rate 97.18%), and the residual polymer was dried, obtaining 29.3 g of regenerated acrylic.

[0068] The purity of the regenerated polyester was 98.1% and the purity of the regenerated acrylic was 95.5% as determined by high performance liquid chromatography (HPLC).

[0069] The polyester recovery rate was 99.7% and the acrylic recovery rate was 97.7% as calculated.

[0070] It should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0071] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and are not intended to limit the protection scope of the present application, and equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A method for recycling polyester / acrylic blended materials, characterized in that, Includes the following steps: Preparation of composite solvent: The components of the composite solvent, by mass percentage, include: N-methylpyrrolidone: 65~85%, ethylene glycol monomethyl ether: 10~30%, sodium metabisulfite: 0.5~5.0%, vitamin E: 0.1~0.3%. The above components are stirred to obtain the composite solvent. Dissolution: The polyester / acrylic blended material is added to the composite solvent and heated and stirred so that the acrylic fiber in the polyester / acrylic blended material dissolves, while the polyester fiber remains suspended in the solution, forming a solid-liquid mixture. Solid-liquid separation: The solid-liquid mixture obtained after dissolution is filtered to obtain polyester filter residue and filtrate containing acrylonitrile. The polyester in the filter residue is recycled polyester. Distillation separation: The filtrate containing acrylonitrile is distilled to separate the composite solvent and acrylonitrile, yielding regenerated acrylonitrile.

2. The method for recycling polyester / acrylic blended materials according to claim 1, characterized in that, In the dissolution step, the polyester / acrylic blended material is dissolved at a temperature of 80~100℃ for 1~2 hours.

3. The method for recycling polyester / acrylic blended materials according to claim 2, characterized in that, During the dissolution step, the stirring speed is 200~300 rpm.

4. The method for recycling polyester / acrylic blended materials according to claim 2, characterized in that, In the dissolution step, the mass ratio of polyester / acrylic blended material to composite solvent is 1:(8~12).

5. The method for recycling polyester / acrylic blended materials according to claim 1, characterized in that, In the solid-liquid separation step, the solid-liquid mixture is subjected to pressure filtration, with the pressure controlled at 0.3~0.5MPa and the filtration accuracy at 0.1~0.2μm.

6. The method for recycling polyester / acrylic blended materials according to claim 1, characterized in that, In the solid-liquid separation step, the polyester filter residue is rinsed with deionized water and then dried at 90~100℃ for 3~4 hours.

7. The method for recycling polyester / acrylic blended materials according to claim 1, characterized in that, In the distillation separation step, the filtrate containing acrylonitrile is subjected to vacuum distillation at a pressure controlled at 0.08~0.09MPa and at 90~100℃.

8. The method for recycling polyester / acrylic blended materials according to claim 1, characterized in that, Before the dissolution step, a pretreatment step is also included. In the pretreatment step, the polyester / acrylic blended material is crushed into polyester / acrylic blended particles with a particle size of 2~5mm. Then, the particles are added to a sodium carbonate solution with a concentration of 5~8% and stirred at a temperature of 60~70℃ to remove impurities.

9. The method for recycling polyester / acrylic blended materials according to claim 8, characterized in that, The polyester / acrylic blended granules, which have been purified by sodium carbonate solution, are rinsed with deionized water and then dried at 80-90℃ for 2-3 hours.

10. The method for recycling polyester / acrylic blended materials according to any one of claims 1 to 9, characterized in that, In polyester / acrylic blended materials, the recovery rate of polyester is ≥97% and the purity is ≥95%; the recovery rate of acrylic fiber is ≥95% and the purity is ≥95%.