METHODS AND SYSTEMS FOR VAPOR-BASED DECOLORIZATION OF POLYESTER TEXTILES

Abstract

A method and a system for vapor-based decolorization of a polyester textile are provided. The method includes: obtaining a textile to be decolorized by adding a phase change material to the polyester textile for mixing, and performing the vapor-based decolorization on the textile to be decolorized. An amount of the phase change material corresponds to a weight of polyester in the polyester textile, and a phase change temperature of the phase change material is not greater than a vapor temperature of a decolorizing agent used in the vapor-based decolorization.

Claims

1. A method for vapor-based decolorization of a polyester textile, comprising: obtaining a textile to be decolorized by adding a phase change material to the polyester textile for mixing; and performing the vapor-based decolorization on the textile to be decolorized, wherein an amount of the phase change material corresponds to a weight of polyester in the polyester textile, and a phase change temperature of the phase change material is not greater than a vapor temperature of a decolorizing agent used in the vapor-based decolorization.

2. The method of claim 1, wherein the obtaining a textile to be decolorized by adding a phase change material to the polyester textile for mixing includes: preprocessing the phase change material before adding the phase change material to the polyester textile, wherein the preprocessing includes: determining a preprocessing manner based on a textile feature of the polyester textile; determining a preprocessing parameter based on the textile feature and the preprocessing manner; and preprocessing the phase change material based on the preprocessing manner and the preprocessing parameter.

3. The method of claim 1, wherein the phase change material is a powdered solid.

4. The method of claim 1, wherein the phase change material is one or more of paraffin and polyethylene glycol.

5. The method of claim 1, wherein the phase change material is a polyethylene glycol-based composite phase change material, and a raw material of the polyethylene glycol-based composite phase change material includes polyethylene glycol.

6. The method of claim 5, wherein the polyethylene glycol-based composite phase change material is a polyethylene glycol-silicon oxide composite material.

7. The method of claim 1, wherein the decolorizing agent used in the vapor-based decolorization is a mixture of a first decolorizing agent and a second decolorizing agent at a preset mass ratio, wherein the first decolorizing agent includes at least one of N,N-dimethylformamide, ethylene glycol, acetic acid, aniline, dimethyl sulfoxide, or N,N-dimethylacetamide; and the second decolorizing agent includes at least one of xylene, naphthalene, or benzophenone.

8. The method of claim 1, wherein the decolorizing agent used in the vapor-based decolorization includes at least one of N,N-dimethylformamide, dimethyl sulfoxide, or ethylene glycol.

9. The method of claim 8, wherein a contact time between vapor of the decolorizing agent and the textile to be decolorized in the vapor-based decolorization is not less than a preset time threshold.

10. The method of claim 9, wherein a process of the vapor-based decolorization includes: obtaining a temperature distribution of the textile to be decolorized through a monitoring device; determining a decolorization state distribution based on the temperature distribution, a textile feature of the textile to be decolorized, and a decolorizing agent feature; and determining a decolorization regulation parameter based on the decolorization state distribution.

11. The method of claim 10, wherein the determining a decolorization regulation parameter based on the decolorization state distribution includes: determining one or more candidate regulation parameters based on the decolorization state distribution; determining, through a damage prediction model, a fabric damage level corresponding to each of the one or more candidate regulation parameters based on the one or more candidate regulation parameters and the decolorization state distribution, the damage prediction model being a machine learning model; and determining the decolorization regulation parameter based on the fabric damage level corresponding to each of the one or more candidate regulation parameters.

12. The method of claim 1, wherein the polyester textile is a polyester-containing textile in which a mass percentage of polyester is within a preset percentage range, and the polyester-containing textile includes at least one of a pure polyester textile, a polyester-cotton textile, a polyester-nylon textile, a polyester-spandex textile, or a polyester blended textile.

13. A system for vapor-based decolorization of a polyester textile, comprising a mixing device, a vapor-based decolorization device, and a processor, wherein the processor is configured to: obtain a textile to be decolorized by adding a phase change material to the polyester textile for mixing; and perform the vapor-based decolorization on the textile to be decolorized through the vapor-based decolorization device, wherein: an amount of the phase change material corresponds to a weight of polyester in the polyester textile, and a phase change temperature of the phase change material is not greater than a vapor temperature of a decolorizing agent used in the vapor-based decolorization.

14. The system of claim 13, wherein the processor is further configured to: preprocess the phase change material before adding the phase change material to the polyester textile, wherein to perform the preprocessing, the processor is further configured to: determine a preprocessing manner based on a textile feature of the polyester textile; determine a preprocessing parameter based on the textile feature and the preprocessing manner; and preprocessing the phase change material based on the preprocessing manner and the preprocessing parameter.

15. The system of claim 13, wherein the phase change material is one or more of paraffin and polyethylene glycol.

16. The system of claim 13, wherein the decolorizing agent used in the vapor-based decolorization is at least one of N,N-dimethylformamide, dimethyl sulfoxide, or ethylene glycol.

17. The system of claim 16, wherein a contact time between vapor of the decolorizing agent and the textile to be decolorized in the vapor-based decolorization is not less than a preset time threshold.

18. The system of claim 17, wherein the processor is further configured to: obtain a temperature distribution of the textile to be decolorized through a monitoring device; determine a decolorization state distribution based on the temperature distribution, a textile feature of the textile to be decolorized, and a decolorizing agent feature; and determine a decolorization regulation parameter based on the decolorization state distribution.

19. The system of claim 18, wherein the processor is further configured to: determine one or more candidate regulation parameters based on the decolorization state distribution; determine, through a damage prediction model, a fabric damage level corresponding to each of the one or more candidate regulation parameters based on the one or more candidate regulation parameters and the decolorization state distribution, the damage prediction model being a machine learning model; and determine the decolorization regulation parameter based on the fabric damage level corresponding to each of the one or more candidate regulation parameters.

20. A non-transitory computer-readable storage medium storing computer instructions, wherein when reading the computer instructions in the storage medium, a computer implements a method for vapor-based decolorization of a polyester textile, the method comprising: obtaining a textile to be decolorized by adding a phase change material to the polyester textile for mixing; and performing the vapor-based decolorization on the textile to be decolorized, wherein an amount of the phase change material corresponds to a weight of polyester in the polyester textile, and a phase change temperature of the phase change material is not greater than a vapor temperature of a decolorizing agent used in the vapor-based decolorization.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present disclosure is further described in terms of exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, where like reference numerals represent similar structures throughout the several views of the drawings, and wherein:

[0012] FIG. 1 is a flowchart of an exemplary process of a method for vapor-based decolorization of a polyester textile according to some embodiments of the present disclosure;

[0013] FIG. 2 shows Kubelka-Munk (K/S) value-wavelength curves before and after vapor-based decolorization of a polyester textile in Example 1 of the present disclosure;

[0014] FIG. 3 shows K/S value-wavelength curves before and after vapor-based decolorization of a polyester textile in Comparative Example 1 of the present disclosure;

[0015] FIG. 4 shows K/S value-wavelength curves before and after vapor-based decolorization of a polyester textile in Example 2 of the present disclosure; and

[0016] FIG. 5 shows K/S value-wavelength curves before and after vapor-based decolorization of a polyester textile in Comparative Example 2 of the present disclosure.

DETAILED DESCRIPTION

[0017] The present disclosure is described in further detail below by way of embodiments. All of the features disclosed in the present disclosure, or all of the operations in the methods or processes disclosed, may be combined in any manner except for mutually exclusive features and/or operations. It should be understood that the preferred embodiments described herein are for illustration and understanding of the present disclosure only, and are not intended to be limiting of the present disclosure.

[0018] The materials, reagents, or the like used in the embodiments of the present disclosure, unless otherwise specified, are commercially available. The experimental techniques for which specific conditions are not indicated in the embodiments are typically carried out under conventional conditions or under the conditions recommended by the manufacturer.

[0019] One or more embodiments of the present disclosure provide a system for vapor-based decolorization of a polyester textile. The system includes a mixing device, a vapor-based decolorization device, and a processor. The processor is configured to obtain a textile to be decolorized by adding a phase change material to the polyester textile for mixing through the mixing device, and perform vapor-based decolorization on the textile to be decolorized through the vapor-based decolorization device.

[0020] In some embodiments, the polyester textile may be a polyester-containing textile in which a mass percentage of polyester is within a preset percentage range. The preset percentage range may be predetermined based on historical experience. For example, the preset percentage range may be from 65% to 99%, etc.

[0021] In some embodiments, the polyester-containing textile may include at least one of a pure polyester textile (e.g., a polyester-containing textile in which the mass percentage of polyester is 99%, etc.), a polyester-cotton textile, a polyester-nylon textile, a polyester-spandex textile, a polyester blended textile, etc.

[0022] The textile to be decolorized refers to a polyester textile that requires vapor-based decolorization. The polyester textile refers to a discarded polyester-containing textile.

[0023] The mixing device refers to a device for mixing the polyester textile and a phase change material. In some embodiments, the mixing device may include a stirring mixer, etc. An operator (e.g., a worker, etc.) may add the polyester textile and the phase change material to the mixing device for mixing to obtain the textile to be decolorized.

[0024] In some embodiments, the mixing device may include a robotic arm, etc. The processor may control the robotic arm to add the polyester textile and the phase change material to the mixing device for mixing to obtain the textile to be decolorized.

[0025] In some embodiments, the processor may send a mixing parameter to the mixing device to control the mixing device to mix the polyester textile and the phase change material. The mixing parameter refers to a parameter related to the operation of the mixing device, such as a duration and a temperature of mixing and heating. More descriptions regarding the mixing parameter may be found elsewhere (e.g., Example 1, etc.) and relevant descriptions thereof.

[0026] The phase change material refers to a material capable of absorbing, storing, or releasing a large amount of thermal energy over a temperature range. During the vapor-based decolorization of the textile to be decolorized, the phase change material may change a temperature of the textile to be decolorized through a state transition (e.g., a transition from liquid to gas, a transition from solid to liquid, etc.). For example, the phase change material may absorb a large amount of thermal energy and change from a liquid state to a gaseous state, thereby reducing the temperature of the textile to be decolorized.

[0027] The vapor-based decolorization device refers to a device for performing vapor-based decolorization on the textile to be decolorized. In some embodiments, the vapor-based decolorization device may include a steam reaction vessel, a steam retort, or the like.

[0028] In some embodiments, a processing metal mesh may be provided in the vapor-based decolorization device. The processing metal mesh may be used to hold the textile to be decolorized and allow vapor to penetrate the textile to be decolorized. In some embodiments, a material of the processing metal mesh may include stainless steel, an alloy, or the like.

[0029] In some embodiments, the vapor-based decolorization device may heat a decolorizing agent to convert the decolorizing agent from a solid state or a liquid state into vapor, and allow the vapor of the decolorizing agent to remain in continuous contact with the textile to be decolorized, thereby performing vapor-based decolorization. The decolorizing agent refers to a reagent capable of removing color from the textile to be decolorized.

[0030] In some embodiments, the system for vapor-based decolorization of a polyester textile may further include a processor. The processor may be configured to process data from at least one device of the system or an external data source. In some embodiments, the processor may be communicatively connected with the mixing device, the vapor-based decolorization device, etc.

[0031] In some embodiments, the processor may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), an application-specific instruction set processor (ASIP), an image processing unit (GPU), a physical operations processing unit (PPU), a digital signal processor (DSP), a controller, a microcontroller unit, a microprocessor, etc., or any combination thereof. In some embodiments, the processor may be integrated with a storage device. The storage device is configured to store data related to the vapor-based decolorization of the polyester textile.

[0032] More descriptions regarding the system for vapor-based decolorization of a polyester textile may be found below and in the relevant descriptions.

[0033] In some embodiments of the present disclosure, the system for vapor-based decolorization of a polyester textile mixes the polyester textile with the phase change material to obtain the textile to be decolorized, and performs vapor-based decolorization on the textile to be decolorized using the vapor-based decolorization device. This allows the vapor of the decolorizing agent to fully contact the polyester textile, thereby achieving effective vapor-based decolorization of the polyester textile. Additionally, the system is capable of processing various types and large amounts of polyester textiles.

[0034] FIG. 1 is a flowchart of an exemplary process of a method for vapor-based decolorization of a polyester textile according to some embodiments of the present disclosure. In some embodiments, process 100 is executed by a processor. As shown in FIG. 1, process 100 includes following operations.

[0035] In 110, a textile to be decolorized may be obtained by adding a phase change material to the polyester textile for mixing.

[0036] In some embodiments, the processor may mix the polyester textile and the phase change material through a mixing device to obtain the textile to be decolorized.

[0037] In some embodiments, an amount of the phase change material corresponds to a weight of polyester in the polyester textile. The corresponding relationship may be preset based on historical experience. For example, the corresponding relationship indicates that the amount of the phase change material ranges from 1% to 5% of the weight of the polyester in the polyester textile. As another example, the corresponding relationship indicates that the amount of the phase change material ranges from 2% to 4% of the weight of the polyester in the polyester textile. As yet another example, the corresponding relationship indicates that the amount of the phase change material may be 3% of the weight of the polyester in the polyester textile.

[0038] In some embodiments, a phase change temperature of the phase change material is not greater than a vapor temperature of a decolorizing agent used in the vapor-based decolorization. The phase change temperature refers to a temperature at which the phase change material is capable of changing state of matter. The vapor temperature of the decolorizing agent refers to a temperature of the vapor after the decolorizing agent is converted from a solid state or a liquid state to vapor due to an increase in temperature.

[0039] In some embodiments, the phase change temperature and the vapor temperature of the decolorizing agent are determined by properties of the phase change material and the decolorizing agent, which may be determined by consulting books, literature, etc.

[0040] In some embodiments, the phase change material may be a powdered solid.

[0041] In some embodiments of the present disclosure, the phase change material in the form of the powdered solid can be dispersed more uniformly on a surface of the polyester textile, thereby increasing a contact area between the phase change material and the polyester textile.

[0042] In some embodiments, the phase change material may include one or more of paraffin, polyethylene glycol, etc. In some embodiments, the paraffin may include industrial-grade paraffin, etc. An average molecular weight of the polyethylene glycol may range from 600 to 20,000, etc. For example, the average molecular weight of the polyethylene glycol may range from 1,000 to 15,000. As another example, the average molecular weight of the polyethylene glycol may range from 5000 to 12000. As yet another example, the average molecular weight of the polyethylene glycol may range from 7000 to 10000. The average molecular weight of the polyethylene glycol refers to an average of the molecular weights of all molecules in the polyethylene glycol.

[0043] In some embodiments, the phase change material may include a polyethylene glycol-based composite phase change material, or the like. A raw material of the polyethylene glycol-based composite phase change material includes polyethylene glycol. For example, the polyethylene glycol-based composite phase change material may be a composite phase change material that consists of polyethylene glycol compounded with expanded graphite, biomass carbon, or silicon oxide, etc.

[0044] In some embodiments, the polyethylene glycol-based composite phase change material may include a polyethylene glycol-silicon oxide composite material, or the like. In some embodiments, the polyethylene glycol-silicon oxide composite material includes a polyethylene glycol-silicon dioxide composite material, or the like.

[0045] In some embodiments of the present disclosure, due to the advantageous properties of the polyethylene glycol or the polyethylene glycol-based composite phase change material, such as suitable phase transition temperature, high latent heat capacity, non-toxicity, low vapor pressure, and excellent thermochemical stability after prolonged use, using the polyethylene glycol or the polyethylene glycol-based composite phase change material as the phase change material can enhance the recyclability and reuse efficiency of the phase change material.

[0046] In some embodiments, in the method for vapor-based decolorization of a polyester textile, preprocessing may be performed on the phase change material before adding the phase change material to the polyester textile through the mixing device.

[0047] In some embodiments, to perform the preprocessing, the processor determines a preprocessing manner based on a textile feature of the polyester textile, determines a preprocessing parameter based on the textile feature and the preprocessing manner, and performs the preprocessing on the phase change material based on the preprocessing manner and the preprocessing parameter through the preprocessing device.

[0048] The textile feature refers to data that characterizes attributes or properties of the polyester textile. In some embodiments, the textile feature may include at least one of a textile structure, a textile type, a knit density, a pile thickness, or the like. The textile structure may include a woven fabric, a knitted fabric, a nonwoven fabric, etc. The textile type may include pure polyester, a high polyester blend, a low polyester blend, etc. The knit density may include high density, medium density, low density, etc. The pile thickness may include high thickness, medium thickness, low thickness, etc.

[0049] In some embodiments, the system for vapor-based decolorization of a polyester textile may include a light source device, a measuring device, etc. The light source device may include a light source box, etc. The measuring device may include a spectrophotometer, a Near-Infrared (NIR) spectrometer, a fabric densitometer, a laser rangefinder, etc. The light source device, the measurement device, or the like may be communicatively connected with the processor.

[0050] In some embodiments, the processor may determine the textile structure based on light transmittance of the polyester textile. For example, the processor may randomly select a preset proportion of the polyester textile as a sample and control the light source device to irradiate a unit area of the sample to obtain, through the spectrophotometer or the like, the light transmittance per unit area of the sample, and the textile structure may be determined based on the light transmittance. The preset proportion may be set in advance based on historical experience, such as 10% of a total volume of the polyester textile. The unit area may be preset, such as 10 square centimeters, etc.

[0051] In some embodiments, if the light transmittance is greater than 50%, the textile structure is a woven fabric. If the light transmittance is between 30% and 50%, the textile structure is a knitted fabric. If the light transmittance is less than 30%, the textile structure is a nonwoven fabric.

[0052] In some embodiments, the processor may determine the textile type based on the mass percentage of polyester. For example, the processor may scan random spots of the polyester textile using the NIR spectrometer or the like to obtain the mass percentage of polyester at the random spots. If the mass percentage of polyester is greater than 95%, the textile type is pure polyester. If the mass percentage of polyester is between 70% and 95%, the textile type is a high polyester blend. If the mass percentage of polyester is less than 70%, the textile type is a low polyester blend. The count of the random points may be preset based on historical experience.

[0053] In some embodiments, the processor may determine the knit density based on a count of needle holes per unit area. For example, the processor may randomly select a preset proportion of the polyester textile as a sample and control a fabric densitometer or the like to obtain the count of needle holes per unit area on the sample, and determine, based on the count of needle holes, the knit density.

[0054] In some embodiments, if the count of needle holes per unit area is greater than 30 stitches/cm.sup.2, the knit density is classified as high density. If the count of needle holes per unit area is between 15 stitches/cm.sup.2 and 30 stitches/cm.sup.2, the knit density is classified as medium density. If the count of needle holes per unit area is less than 15 stitches/cm.sup.2, the knit density is classified as low density.

[0055] In some embodiments, the processor may determine the pile thickness based on a height of the polyester textile. For example, the processor may measure the height of the polyester textile using a laser rangefinder or the like. If the height is less than 30 cm, the pile thickness classified as low thickness. If the height is between 30 cm and 50 cm, the pile thickness is classified as medium thickness. If the height is greater than 50 cm, the pile thickness is classified as high thickness.

[0056] In some embodiments, the preprocessing manner may include at least one of surface modification, microencapsulation, carrier integration, plasma processing, hybrid processing, etc. The hybrid processing may be a combination of the surface modification and the microencapsulation, a combination of the surface modification and the plasma processing, or the like.

[0057] The surface modification may include adding a modifier to the phase change material. The microencapsulation include encapsulating the phase change material in microscopic capsules made of a polymer, or the like. The carrier integration may include binding the phase change material to a carrier (e.g., expanded graphite, silica gel, etc.). The plasma treatment may include using plasma to process a surface of the phase change material.

[0058] In some embodiments, the preprocessing device may include a high-energy ball mill, a spray dryer, an electrostatic spinning machine, a radiofrequency plasma cleaner, etc. The preprocessing device may be communicatively connected with the processor.

[0059] In some embodiments, the processor may determine the preprocessing manner based on the textile feature. For example, the processor may determine the preprocessing manner by querying a first preset table based on the textile feature.

[0060] The first preset table may include a relationship between textile features and preprocessing manners. In some embodiments, the processor may construct the first preset table based on experimental data. For example, a technician may process each set of textile features using different preprocessing manners and upload the experimental data to the processor. For each set of textile features, the processor screens experimental data in which the decolorization rate is greater than a decolorization rate threshold, and records the preprocessing manner in the experimental data as the preprocessing manner corresponding to the set of textile features in the first preset table. The decolorization rate threshold may be set based on experience. The decolorization rate may be obtained by measurement, such as using a colorimeter, etc.

[0061] Merely by way of example, for a set of textile features in which the textile structure is a woven fabric, the textile type is pure polyester, the knit density is high density, the pile thickness is medium thickness, and the preprocessing manner in which the decolorization rate is greater than the decolorization rate threshold is a hybrid treatment combining microencapsulation and the plasma treatment, then the preprocessing manner corresponding to that single set of textile features in the first preset table is the hybrid treatment combining microencapsulation and plasma treatment.

[0062] The preprocessing parameter refers to a parameter corresponding to the preprocessing manner. In some embodiments, the preprocessing parameter for the surface modification may include a modifier type (e.g., a silane coupling agent, etc.), a modifier dosage, a treatment temperature, a treatment time, or the like. The preprocessing parameter for the microencapsulation may include a capsule particle size, a shell-to-core ratio (e.g., a mass or volume ratio of a wall material to a core material), a treatment time, or the like. The preprocessing parameter for the carrier integration may include a carrier porosity level, a loading rate, a treatment time, or the like. The preprocessing parameter for the plasma treatment may include a power level, a treatment time, a gas type (e.g., O.sub.2, Ar, etc.), or the like.

[0063] In some embodiments, the processor may determine the preprocessing parameter based on the textile feature and the preprocessing manner. For example, the processor may construct a target feature vector based on the textile feature and the preprocessing manner, query a first vector database to identify a first feature vector that satisfies a first matching condition, and determine a label corresponding to the first feature vector as the preprocessing parameter corresponding to the target feature vector. The first matching condition may include having the highest similarity to the target feature vector. The similarity between vectors may be negatively correlated to a vector distance between the vectors. The vector distance may include a cosine distance, a Euclidean distance, etc.

[0064] In some embodiments, the first vector database may be preset based on experimental data and include a plurality of first feature vectors and a label corresponding to each of the first feature vectors. For example, for each set of textile features, the processor filters experimental data in which the decolorization rate is greater than the decolorization rate threshold, extracts the preprocessing manner and the preprocessing parameter in the experimental data, constructs a first feature vector based on the textile feature and the preprocessing manner in the experimental data, and designates the preprocessing parameter in the experimental data as the label corresponding to the first feature vector.

[0065] By way of example, for a set of textile features in which the textile structure is a woven fabric, the textile type is pure polyester, the knit density is high density, the pile thickness is low thickness, the preprocessing manner is microencapsulation, and the decolorization rate is greater than the decolorization rate threshold, the preprocessing parameter may include a capsule particle size ranging from 5 m to 10 m, a shell-to-core ratio of 1:5, and a treatment time of 30 minutes. Therefore, the label of the first feature vector corresponding to the set of textile features is a capsule particle size ranging from 5 m to 10 m, a shell-to-core ratio of 1:5, and a treatment time of 30 minutes.

[0066] In some embodiments, the processor may send the preprocessing manner and the preprocessing parameter to a corresponding preprocessing device to control the preprocessing device to preprocess the phase change material.

[0067] In some embodiments of the present disclosure, since the powdered phase change material is prone to agglomeration, preprocessing of the phase change material through microencapsulation or surface modification enhances the dispersion uniformity of the phase change material in the polyester textile and reduces localized accumulation of the phase change material. At the same time, the preprocessed phase change material may respond more quickly to the temperature change of the vapor of the decolorizing agent, accelerating the phase change process, and rapidly facilitating the penetration of the vapor of the decolorizing agent through the stacked polyester textile. Microencapsulation prevents excessive permeation of phase change material into the polyester textile during decolorization, thereby reducing the difficulty of recovering the phase change material.

[0068] In 120, vapor-based decolorization may be performed on the textile to be decolorized.

[0069] In some embodiments, the processor may perform the vapor-based decolorization on the textile to be decolorized through a vapor-based decolorization device. The vapor-based decolorization device may be configured to perform the vapor-based decolorization on the textile to be decolorized by heating the decolorizing agent to a boiling point (a point at which the decolorizing agent is converted from liquid to vapor) of the decolorizing agent and keeping the vapor of the decolorizing agent in contact with the textile to be decolorized.

[0070] In some embodiments, the decolorizing agent used in the vapor-based decolorization is a mixture of a first decolorizing agent I and a second decolorizing agent Il at a preset mass ratio. The preset mass ratio may be predetermined based on historical experience. For example, the preset mass ratio may be 1:0.1-10, i.e., the mass of the second decolorizing agent ranges from 0.1 times to 10 times the mass of the first decolorizing agent. As another example, the preset mass ratio may be 1:0.5. As yet another example, the preset mass ratio may be 1:4. As a further example, the preset mass ratio may be 1:8.

[0071] In some embodiments, the first decolorizing agent includes at least one of N,N-dimethylformamide, ethylene glycol, acetic acid, aniline, dimethyl sulfoxide, or N,N-dimethylacetamide. The second decolorizing agent may include at least one of xylene, naphthalene, or benzophenone. The first decolorizing agent has a higher polarity than the second decolorizing agent.

[0072] In some embodiments, the decolorizing agent used for the vapor-based decolorization further includes at least one of N,N-dimethylformamide, dimethyl sulfoxide, or ethylene glycol.

[0073] In some embodiments of the present disclosure, a high-polarity decolorizing agent can quickly dissolve a dye substance in the polyester textile during the vapor-based decolorization and improve the effect of the vapor-based decolorization, and a low-polarity decolorizing agent has a polarity similar to the polarity of the phase change material. Therefore, using a mixture of decolorizing agents with different polarities helps guide the vapor of the decolorizing agent to penetrate through densely stacked or tightly knitted polyester textile, thereby ensuring sufficient contact between the decolorizing vapor and the textile, and enhancing the uniformity of the vapor-based decolorization.

[0074] In some embodiments, the operator or the processor controls a robotic arm to add the polyester textile and the preprocessed phase change material to the mixing device for mixing to obtain the textile to be decolorized.

[0075] In some embodiments, the vapor-based decolorization may include the following operations: the operator or the processor controls the robotic arm to place the textile to be decolorized in the processing metal mesh of the vapor-based decolorization device, the vapor-based decolorization device heats the decolorizing agent to the boiling point of the decolorizing agent (at which time the decolorizing agent is converted from a liquid state to vapor), stops the heating when a contact time of the vapor of the decolorizing agent with the textile to be decolorized is not less than a preset time threshold. After the temperature of the decolorizing agent solution is cooled down to room temperature, the vapor-based decolorization of the textile to be decolorized is completed.

[0076] In some embodiments, the system for vapor-based decolorization of a polyester textile may also include a monitoring device, a camera device, etc. The monitoring device refers to a device that acquires the temperature of the textile to be decolorized during the vapor-based decolorization. In some embodiments, the monitoring device may include a probe-type temperature sensor, etc. The camera device may include a camera, etc.

[0077] In some embodiments, the processor may obtain a temperature distribution of the textile to be decolorized through the monitoring device, determine a decolorization state distribution based on the temperature distribution, a textile feature of the textile to be decolorized, and a decolorizing agent feature, and determine a decolorization regulation parameter based on the decolorization state distribution. The textile feature of the textile to be decolorized is also referred to as the textile feature of the polyester textile, more descriptions regarding the textile feature may be found in the related desciptions above.

[0078] The temperature distribution may characterize a distribution of temperatures in different zones of the textile to be decolorized.

[0079] In some embodiments, the processor may collect temperatures of a plurality of monitoring zones or monitoring sub-zones on the textile to be decolorized during the vapor-based decolorization by the monitoring device to obtain the temperature distribution of the textile to be decolorized.

[0080] In some embodiments, the processor may determine the plurality of monitoring zones by dividing the textile to be decolorized through vertical stratification, etc. For example, the processor may obtain an image of the textile to be decolorized by the camera device and identify stacked layers of the textile to be decolorized by an image recognition algorithm or the like, and designate each of the stacked layers as a monitoring zone. If a height of the vapor-based decolorization device is greater than a stacked thickness of the textile to be decolorized, the processor designates a top cavity area of the vapor-based decolorization device as a monitoring zone. The image recognition algorithm may include feature extraction, a deep learning network, etc.

[0081] In some embodiments, the processor may further divide each monitoring zone. For example, the processor may divide each monitoring zone into a plurality of monitoring sub-zones along a length direction and a width direction of the vapor-based decolorization device. Sizes of the monitoring sub-zones may be the same or different.

[0082] In some embodiments, each of the monitoring zones and/or the monitoring sub-zones may be provided with the monitoring device.

[0083] The decolorizing agent feature refers to data that characterizes a property of the decolorizing agent. In some embodiments, the decolorizing agent feature may include a decolorizing agent type, etc. The decolorizing agent feature may be preset.

[0084] The decolorization state distribution may characterizes a degree of decolorization of the textile to be decolorized in each of the plurality of monitoring zones after the vapor-based decolorization.

[0085] In some embodiments, the processor may determine the decolorization state distribution based on the temperature distribution, the textile feature, and the decolorizing agent feature by using a prediction model.

[0086] In some embodiments of the present disclosure, the prediction model may be a machine learning model. For example, the prediction model may include a Convolutional Neural Network (CNN) model, a Neural Network (NN) model, a customized model structure, or the like, or any combination thereof.

[0087] In some embodiments of the present disclosure, the processor may train the prediction model based on a large number of first training samples with first labels using a gradient descent manner, etc. For example, the processor may input a plurality of first training samples with first labels into an initial prediction model, construct a loss function based on the first labels and outputs of the initial prediction model, and iteratively update the parameters of the initial prediction model using techniques such as gradient descent based on the loss function. When the loss function of the initial prediction model satisfies a preset condition, the training of the prediction model is completed. The preset condition may include the loss function converging, a count of iterations reaching a set value, or the like.

[0088] In some embodiments of the present disclosure, the first training sample may include a sample temperature distribution and a sample textile feature of a sample textile to be decolorized, and a sample decolorizing agent feature. The first label may be an actual decolorization state distribution corresponding to the first training sample.

[0089] In some embodiments of the present disclosure, the first training sample and the first label may be obtained based on historical data. For example, the processor may designate a sample decolorizing agent feature and a sample textile feature of a sample textile to be decolorized from a historical decolorization process, as well as a historical temperature distribution of the sample textile to be decolorized at a first historical time point in the historical decolorization process as the first training sample. The technician may pause the vapor-based decolorization at the first historical time point, manually label the degrees of decolorization of the plurality of monitoring zones, and obtain an actual decolorization state distribution (i.e., the first label) corresponding to the first training sample. The first historical time is preset based on historical experience.

[0090] The decolorization regulation parameter refers to a parameter for controlling the operation of the vapor-based decolorization device. In some embodiments, the decolorization regulation parameter may include a decolorization time, a decolorizing agent dosage, a heating power level, etc. The decolorization time may be a contact time during which the vapor of the decolorizing agent is in contact with the textile to be decolorized.

[0091] In some embodiments, an initial decolorization regulation parameter at the beginning of the vapor-based decolorization may be preset based on historical experience, and the processor may determine the decolorization regulation parameter based on the decolorization state distribution of the textile to be decolorized during the vapor-based decolorization.

[0092] In some embodiments, the processor may determine the decolorization regulation parameter based on the decolorization state distribution. For example, the processor may construct a decolorization feature vector based on the decolorization state distribution, query the second vector database for a second feature vector that satisfies a second matching condition, and designate the label corresponding to the second feature vector as the decolorization regulation parameter corresponding to the decolorization feature vector. The second matching condition may include having the highest similarity with the decolorization feature vector.

[0093] In some embodiments, the second vector database may be preset based on historical data and include a plurality of second feature vectors and a label corresponding to each of the second feature vectors. For example, the processor may determine, based on the historical data, a plurality of historical decolorization processes in which decolorization rates are greater than the decolorization rate threshold, and construct a plurality of second feature vectors based on historical decolorization state distributions in the plurality of historical decolorization processes. For a second feature vector among the plurality of second feature vectors, the processor may determine a historical decolorization regulation parameter used in the historical decolorization process corresponding to the second feature vector, and designate the historical decolorization regulation parameter as the label corresponding to the second feature vector.

[0094] In some embodiments of the present disclosure, by real-time monitoring of the temperature distribution within the polyester textile during the vapor-based decolorization, predicting the decolorization state distribution based on the temperature distribution and the feature of the polyester textile, and subsequently adjusting the decolorization regulation parameter, the system can mitigate inconsistencies in the decolorization degree caused by variations in the stacking thickness or the knitting density of the polyester textile, thereby significantly improving the decolorization rate.

[0095] In some embodiments, the processor may determine one or more candidate regulation parameters based on the decolorization state distribution, determine a fabric damage level corresponding to each of the one or more candidate regulation parameters through a damage prediction model based on the one or more candidate regulation parameters and the decolorization state distribution, and determine the decolorization regulation parameter based on the fabric damage level corresponding to each of the one or more candidate regulation parameters.

[0096] A candidate regulation parameter refers to a decolorization regulation parameter to be determined.

[0097] In some embodiments, the processor may determine one or more candidate regulation parameters based on the decolorization state distribution. For example, the processor may determine one or more candidate regulation parameters based on the decolorization state distribution by querying a second preset table.

[0098] The second preset table may include a relationship between decolorization state distributions and one or more candidate regulation parameters corresponding to each of the decolorization state distributions. In some embodiments, the processor may construct the second preset table based on experimental data. For example, the technician may process each of a plurality of decolorization state distributions using different decolorization regulation parameters and upload the experimental data to the processor. For each decolorization state distribution, the processor may screen the experimental data in which the decolorization rate is greater than the decolorization rate threshold, determine one or more decolorization regulation parameters corresponding to the experimental data as the one or more candidate regulation parameters corresponding to the decolorization state distribution, and record the one or more decolorization regulation parameters in the second preset table.

[0099] The fabric damage level may characterize a degree of damage caused to the textile to be decolorized after prolonged contact with the vapor of the decolorizing agent during the vapor-based decolorization. In some embodiments, the fabric damage level may include mild, moderate, server, etc.

[0100] In some embodiments, the processor may determine the fabric damage level through the damage prediction model based on the one or more candidate regulation parameters and the decolorization state distribution. In some embodiments, the damage prediction model may be a machine learning model. For example, the damage prediction model may include a Convolutional Neural Network (CNN) model, a Neural Network (NN) model, a customized model structure, or the like, or any combination thereof.

[0101] In some embodiments, the processor may train the damage prediction model based on a large number of second training samples with second labels by a gradient descent manner, etc. The training process of the damage prediction model is similar to the training process of the prediction model, and more descriptions may be found in the related descriptions above.

[0102] In some embodiments, the second training sample may include a sample decolorization state distribution of a sample textile to be decolorized and a sample regulation parameter. The second label may include an actual fabric damage level corresponding to the second training sample. The second training sample may be obtained based on historical data, and the second label may be obtained based on manual labeling.

[0103] In some embodiments, the processor may train the damage prediction model and the prediction model jointly based on a large number of third training samples with third labels. The third training sample may include a sample temperature distribution and a sample textile feature of a sample textile to be decolorized, a sample decolorizing agent feature, and a sample regulation parameter. The third label may be an actual fabric damage level corresponding to the third training sample. The third training sample may be obtained based on historical data, and the third label may be obtained based on manual labeling.

[0104] In some embodiments, a process of joint training of the damage prediction model and the prediction model includes: inputting sample temperature distributions, sample textile features, and sample decolorizing agent features of a plurality of third training samples into an initial prediction model to obtain a plurality of decolorization state distributions output by the initial prediction model, then inputting the plurality of decolorization state distributions and sample regulation parameters of the plurality of third training samples into an initial damage prediction model, constructing a loss function based on the third labels and prediction results of the initial damage prediction model, and iteratively updating the initial damage prediction model and the initial prediction model based on the loss function through a gradient descent technique, or the like. The joint training of the damage prediction model and the prediction model are completed when the loss function satisfies a preset condition. The preset condition may include the loss function converging, a count of iterations reaching a set value, or the like.

[0105] In some embodiments, the processor may determine the decolorization regulation parameter based on the fabric damage level corresponding to each of the one or more candidate regulation parameters. For example, the processor may determine the candidate regulation parameters corresponding to the smallest fabric damage level as the decolorization regulation parameter based on the fabric damage level(s) corresponding to the one or more candidate regulation parameters.

[0106] In some embodiments, if a plurality of candidate regulation parameters correspond to the same fabric damage level, the processor may determine a cost of each of the plurality of candidate regulation parameters, and determine the candidate regulation parameter with the smallest cost as the decolorization regulation parameter.

[0107] In some embodiments, the processor may perform a weighted summation on the decolorization time and the decolorizing agent dosage in the candidate regulation parameter to obtain the cost of the candidate regulation parameter. A weight for the decolorization time and a weight for the decolorizing agent dosage may be set in advance based on historical experience.

[0108] In some embodiments, the processor may normalize the decolorization time and the decolorizing agent dosage in the candidate regulation parameter before the weighted summation.

[0109] In some embodiments of the present disclosure, by predicting the potential damage each one or more candidate regulation parameters may cause to the textile to be decolorized and selecting the candidate regulation parameter that has the minimal damage and/or the lowest cost as the decolorization regulation parameter, the decolorization rate is guaranteed, the damage to the textile to be decolorized is minimized, and the cost of the vapor-based decolorization is reduced.

[0110] The method for vapor-based decolorization of a polyester textile is further illustrated by the following Examples and Comparative Examples. The operator or the processor control the robotic arm to place the textile to be decolorized in the processing metal mesh of the vapor-based decolorization device. The vapor-based decolorization device heats the decolorizing agent to the boiling point (at this time, the decolorizing agent is converted from liquid to vapor) of the decolorizing agent. The heating is stopped when the contact time between the vapor of the decolorizing agent and the textile to be decolorized is not less than a preset time threshold. After the temperature of the decolorizing agent solution is cooled down to room temperature, the vapor-based decolorization of the textile to be decolorized is completed.

Example 1

[0111] In Example 1, a large amount of polyester textile was processed through the following operations:

[0112] In S11, the operator uniformly mixed a polyester textile containing 2.5 kg of polyester (e.g., a pure polyester curtain in which the mass percentage of polyester is 65%) with 25 g (1% of the weight of the polyester in the polyester textile) of powdered polyethylene glycol having an average molecular weight of 10,000 through the mixing device to obtain a textile to be decolorized.

[0113] S12: The textile to be decolorized was placed in the processing metal mesh of the vapor-based decolorization device, and the vapor-based decolorization was carried out with 60 L of N, N-dimethylformamide as the decolorizing agent.

[0114] The vapor-based decolorization includes the following operations: the decolorizing agent was stirred and heated in the vapor-based decolorization device to its boiling point of 153 C., and the temperature was maintained for 2 hours, ensuring that the vapor of the decolorizing agent contacted with the textile to be decolorized.

[0115] The heating was stopped, and the decolorizing agent solution was allowed to cool to room temperature. The decolorized polyester textile was then removed.

[0116] In Example 1, the phase change temperature of the phase change material of the polyethylene glycol was 65 C., which was lower than the vapor temperature of the decolorizing agent.

Comparative Example 1

[0117] Comparative Example 1 is essentially the same as Example 1, except that no phase change material is added. Specifically:

[0118] The operator placed a polyester textile containing 2.5 kg of polyester in the processing metal mesh of the vapor-based decolorization device. 60 L of N,N-dimethylformamide was used as the decolorizing agent. The decolorizing agent was stirred and heated in the vapor-based decolorization device to its boiling point of 153 C., and the temperate was maintained for 2 hours. The heating was stopped, and the decolorizing agent solution was allowed to cool to room temperature. The decolorized polyester textile was then removed.

[0119] FIG. 2 shows K/S value-wavelength curves before and after vapor-based decolorization of the polyester textile in Example 1 of the present disclosure.

[0120] FIG. 3 shows K/S value-wavelength curves before and after vapor-based decolorization of the polyester textile in Comparative Example 1 of the present disclosure.

[0121] In some embodiments, the processor may obtain the K/S values and the wavelengths before and after the vapor-based decolorization of the polyester textile in Example 1 by a spectrophotometer or the like, and determine the decolorization rate of Example 1 based on the K/S values at the same wavelength before and after the vapor-based decolorization. The manner for determining the decolorization rate of Comparative Example 1 is similar to the manner for determining the decolorization rate of Example 1.

[0122] The K/S value-wavelength curves before and after the vapor-based decolorization in Example 1 are shown in FIG. 2. The K/S value-wavelength curves before and after the vapor-based decolorization in Comparative Example 1 are shown in FIG. 3.

[0123] The K/S value may be used to indicate a color depth of the polyester textile. The higher the K/S value is, the deeper the color is.

[0124] In some embodiments, the decolorization rate is positively correlated to a difference between K/S values before and after the vapor-based decolorization. For example, the processor may determine the decolorization rate according to Equation (1):

[00001]$\begin{array}{cc}T=\left(a1-a2\right)a1100\%,& \left(1\right)\end{array}$

where T denotes the decolorization rate, al denotes a K/S value before the vapor-based decolorization, and a2 denotes a K/S value after the vapor-based decolorization.

[0125] As shown in FIG. 2 and FIG. 3, the decolorization rate of Example 1 is 97.1%, and the decolorization rate of Comparative Example 1 is 72.9%. The results showed that when processing a polyester textile containing 2.5 kg of polyester, the addition of 1wt % (1% of the weight of polyester in the polyester textiles) of the phase change material using the manner of Example 1 markedly improves the decolorization rate of the polyester textile as compared to Comparative Example 1.

Example 2

[0126] In Example 2, only 40% of the amount of the polyester textile in Example 1 was processed through the following operations:

[0127] In S21, the operator uniformly mixed a polyester textile containing 1 kg of polyester (e.g., a pure polyester curtain in which the mass percentage of polyester is 65%) with 25 g (2.5% of the weight of the polyester in the polyester textile) of powdered polyethylene glycol having an average molecular weight of 10,000 through the mixing device to obtain a textile to be decolorized.

[0128] In S22, the textile to be decolorized was placed in the processing metal mesh of the vapor-based decolorization device, and the vapor-based decolorization was carried out with 60 L of N,N-dimethylformamide as the decolorizing agent.

[0129] The vapor-based decolorization includes the following operations: the decolorizing agent was stirred and heated in the vapor-based decolorization device to its boiling point of 153 C., and the temperature was maintained for 2 hours, ensuring that the vapor of the decolorizing agent contacted with the textile to be decolorized. The heating was stopped, and the decolorizing agent solution was allowed to cool to room temperature. The decolorized polyester textile was then removed.

[0130] In Example 2, the phase change temperature of the phase change material of the polyethylene glycol was 65 C., which was not greater than the vapor temperature of the decolorizing agent.

[0131] FIG. 4 shows K/S value-wavelength curves before and after vapor-based decolorization of the polyester textile in Example 2 of the present disclosure.

[0132] In some embodiments, the manner for calculating the decolorization rate of Example 2 is similar to the manner for calculating the decolorization rate of Example 1. As shown in FIG. 4, the decolorization rate of Example 2 is 98.9%.

Comparative Example 2

[0133] Comparative Example 2 is essentially the same as Comparative Example 1, except that only 40% of the amount of the polyester textile in Comparative Example 1 was processed. Specifically:

[0134] The operator placed a polyester textile containing 1 kg of polyester in the processing metal mesh of the vapor-based decolorization device. 60 L of N,N-dimethylformamide was used as the decolorizing agent. The decolorizing agent was stirred and heated in the vapor-based decolorization device to its boiling point of 153 C., and the temperate was maintained for 2 hours. The heating was stopped, and the decolorizing agent solution was allowed to cool to room temperature. The decolorized polyester textile was then removed.

[0135] FIG. 5 shows K/S value-wavelength curves before and after vapor-based decolorization of the polyester textile in Comparative Example 2 of the present disclosure.

[0136] In some embodiments, the manner for calculating the decolorization rate of Comparative Example 2 is similar to the manner for calculating the decolorization rate of Example 1. As shown in FIG. 5, the decolorization rate of Comparative Example 2 is 98.8%.

[0137] Referring to FIGS. 2-5, it is shown that the method for vapor-based decolorization of a polyester textile can improve the decolorization rate of the polyester textile. When the amount of the textile to be decolorized is 1 kg, the method increases the decolorization rate from 98.8% to 98.9%. When the amount of the textile to be decolorized is 2.5 kg, the method significantly enhances the decolorization rate from 72.9% to 97.1%.

[0138] The results show that the method for vapor-based decolorization of a polyester textile improves the decolorization rate of the polyester textile by adding the phase change material, successfully improves the decolorization rate. The method particularly addresses the issues of low and uneven decolorization rates due to the increased amount of textile to be decolorized by ensuring insufficient contact time between the vapor of the decolorizing agent and the textile.

Example 3

[0139] Example 3 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the difference is that a polyester textile containing 1.2 kg of polyester (e.g., a polyester-cotton duvet cover in which the mass percentage of polyester is 83%) was uniformly mixed with 12 g (1% of the weight of the polyester in the polyester textile) of industrial paraffin to obtain a textile to be decolorized. 60 L of dimethyl sulfoxide was used as the decolorizing agent.

[0140] The decolorization rate of Example 3 was calculated to be 98.8% according to the manner for calculating the decolorization rate described in Example 1.

Example 4

[0141] Example 4 is basically the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 1.5 kg of polyester (e.g., discarded polyester-nylon yarn in which the mass percentage of polyester is 72%) was uniformly mixed with 45 g (3% of the weight of the polyester in the polyester textile) of polyethylene glycol having an average molecular weight of 600 to obtain a textile to be decolorized. 60 L of ethylene glycol was used as the decolorizing agent. The contact time between the vapor of the decolorizing agent and the textile to be decolorized was 0.5 hours.

[0142] The decolorization rate of Example 4 was calculated to be 98.3% according to the manner for calculating the decolorization rate described in Example 1.

Example 5

[0143] Example 5 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 1.8 kg of polyester (e.g., a discarded polyester-spandex garment in which the mass percentage of polyester is 90%) was uniformly mixed with 18 g (1% of the weight of the polyester in the polyester textiles) of industrial paraffin to obtain a textile to be decolorized. A 60 L decolorizing agent was prepared by mixing N,N-dimethylacetamide (decolorizing agent I, also referred to as the first decolorizing agent) and xylene (decolorizing agent II, also referred to as the second decolorizing agent) at a mass ratio of 1:0.1 for decolorization. The contact time between the vapor of the decolorizing agent and the textile to be decolorized was 4 hours.

[0144] The decolorization rate of Example 5 was calculated to be 98.3% according to the manner for calculating the decolorization rate described in Example 1.

Example 6

[0145] Example 6 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 2.5 kg of polyester (e.g., a polyester blend duvet cover in which the mass percentage of polyester is 80%) was uniformly mixed with 125 g (5% of the weight of the polyester in the polyester textile) of a polyethylene glycol-silicon dioxide composite material to obtain a textile to be decolorized. A 60 L decolorizing agent was prepared by mixing ethylene glycol (decolorizing agent I) and naphthalene (decolorizing agent II) at a mass ratio of 1:5 for decolorization. The contact time between the vapor of the decolorizing agent and the textile to be decolorized was 6 hours.

[0146] The decolorization rate of Example 6 was calculated to be 98.4% according to the manner for calculating the decolorization rate of Example 1.

Example 7

[0147] Example 7 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 5 kg of polyester (e.g., a polyester-cotton pillowcase in which the mass percentage of polyester is 90%) was uniformly mixed with 75 g (1.5% of the weight of the polyester in the polyester textile) of polyethylene glycol with an average molecular weight of 2,000 to obtain a textile to be decolorized. A 60 L decolorizing agent was prepared by mixing a decolorizing agent I (e.g., aniline) and a decolorizing agent II (e.g., benzophenone) at a mass ratio of 1:10 for decolorization.

[0148] The decolorization rate of Example 7 was calculated to be 98.2% according to the manner for calculating the decolorization rate of Example 1.

[0149] In some embodiments, selecting a polyethylene glycol with an average molecular weight ranging from 600 to 20,000 as the phase change material can improve the decolorization rate of the polyester textile.

Example 8

[0150] Example 8 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 10 kg of polyester (e.g., polyester-spandex fabric in which the mass percentage of polyester is 65%) was uniformly mixed with 200 g (2% by weight of the polyester in the polyester textile) of polyethylene glycol with an average molecular weight of 10,000 to obtain a textile to be decolorized. A decolorizing agent I was prepared by mixing equal amounts of dimethyl sulfoxide and N,N-dimethylacetamide, and a decolorizing agent Il was prepared by mixing xylene and benzophenone at a mass ratio of 1:2. The decolorizing agent I and the decolorizing agent Il were mixed to prepare a 240 L composite decolorizing agent for decolorization, and the mass ratio of the decolorizing agent I to the decolorizing agent Il in the composite decolorizing agent was 1:6. The contact time between the vapor of the decolorizing agent and the textile to be decolorized was 1 hours.

[0151] The decolorization rate of Example 8 was calculated to be 97.4% according to the manner for calculating the decolorization rate of Example 1.

Example 9

[0152] Example 9 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 20 kg of polyester (e.g., polyester-cotton fibers in which the mass percentage of polyester is 65%) was uniformly mixed with 800 g (4% by weight of the polyester in the polyester textile) of a polyethylene glycol-silicon dioxide composite material to obtain a textile to be decolorized. A decolorizing agent I was prepared by mixing ethylene glycol, acetic acid, and aniline at a mass ratio of 1:3:5, and a decolorizing agent Il was prepared by mixing xylene, naphthalene, and benzophenone at a mass ratio of 1:6:2. The decolorizing agent I and the decolorizing agent Il were mixed to prepare a 240 L composite decolorizing agent for decolorization, and the mass ratio of the decolorizing agent I to the decolorizing agent Il in the composite decolorizing agent was 1:8.

[0153] The decolorization rate of Example 9 was calculated to be 97.2% according to the manner for calculating the decolorization rate of Example 1.

Example 10

[0154] Example 10 is essentially the same as Example 1, and the apart from the conventional adaptations in the field, the differences are: a polyester textile containing 10 kg of polyester (e.g., pure polyester fibers in which the mass percentage of polyester is 70%) was uniformly mixed with 200 g (2% of the weight of the polyester in the polyester textiles) of industrial paraffin to obtain a textile to be decolorized. A decolorizing agent I was prepared by mixing N, N-dimethylformamide and ethylene glycol at a mass ratio of 1:3, a decolorizing agent Il was prepared by mixing xylene and naphthalene at a mass ratio of 1:6. The decolorizing agent I and the decolorizing agent II were mixed to prepare a 240 L composite decolorizing agent for decolorization, and the mass ratio of the decolorizing agent I to the decolorizing agent Il in the composite decolorizing agent was 1:10. The contact time between the vapor of the decolorizing agent and the textile to be decolorized was 1.5 hours.

[0155] The decolorization rate of Example 10 was calculated to be 97.4% according to the manner for calculating the decolorization rate of Example 1.

Example 11

[0156] Example 11 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 10 kg of polyester (e.g., pure polyester fibers in which the mass percentage of polyester is 80%) was uniformly mixed with 200 g (2% by weight of the polyester in the polyester textiles) of a polyethylene glycol-silicon dioxide composite material to obtain a textile to be decolorized. A decolorizing agent I was prepared by mixing N,N-dimethylformamide and ethylene glycol at a mass ratio of 1:3, and a decolorizing agent Il was prepared by mixing xylene and naphthalene at a mass ratio of 1:6. The decolorizing agent I and decolorizing agent II were mixed to prepare a 240 L composite decolorizing agent for decolorization, and the mass ratio of the decolorizing agent I to the decolorizing agent Il in the composite decolorizing agent was 1:10. The contact time between the vapor of the decolorizing agent and the textile to be decolorized was 1.5 hours.

[0157] The decolorization rate of Example 11 was calculated to be 97.4% according to the manner for calculating the decolorization rate of Example 1.

Example 12

[0158] Example 12 is essentially the same as Example 1, and apart from the conventional adaptations in the field, the differences are: a polyester textile containing 10 kg of polyester (e.g., polyester-cotton fibers in which the mass percentage of polyester is 70%) was uniformly mixed with 200 g (2% of the weight of the polyester in the polyester textile) of polyethylene glycol with an average molecular weight of 2,000 to obtain a textile to be decolorized. A decolorizing agent I was prepared by mixing N,N-dimethylformamide and ethylene glycol at a mass ratio of 1:3, and a decolorizing agent Il was prepared by mixing xylene and naphthalene at a mass ratio of 1:6. The decolorizing agent I and the decolorizing agent Il were mixed to prepare a 240 L composite decolorizing agent for decolorization, and the mass ratio of the decolorizing agent I and the decolorizing agent Il in the composite decolorizing agent was 1:10. The contact time between the vapor of the decolorizing agent and the textile to be decolorized was 1.5 hours.

[0159] The decolorization rate of Example 12 was calculated to be 97.8% according to the manner for calculating the decolorization rate of Example 1.

[0160] In some embodiments, the closer the phase change temperature of the phase change material is to the vapor temperature of the decolorizing agent used in the vapor-based decolorization, the better the decolorization effectiveness is.

[0161] In some embodiments, the polyester textile includes an edge trimming, a discarded filament, yarn waste, a fabric scrap, etc., produced during a textile production process. For example, the polyester textile includes a used garment, a discarded home textile, an end-of-life industrial textile, or the like.

[0162] In some embodiments of the present disclosure, the phase change material with phase-changing properties is added to the polyester textile. When the vapor of the decolorizing agent rises and increases the temperature of the stacked polyester textile, the phase change material inside the stacked polyester textile reaches the phase change temperature, and a phase change occurs. Thus, a local temperature difference within the polyester textile is formed, which guides the vapor of the decolorizing agent to penetrate the stacked polyester textile with high a relatively great stacking thickness or a relatively large fabric knitting density, so that the vapor of the decolorizing agent and polyester textile can be fully contacted to improve the uniformity of decolorization, thereby enhancing the decolorization rate.

[0163] In some embodiments of the present disclosure, the phase change material and the dye molecules in the polyester textile are dissolved in the vapor of the decolorizing agent to form a decolorizing waste liquid. The phase change material may be subsequently recovered from the waste liquid through distillation, thereby achieving resource conservation and reuse.

[0164] In some embodiments, one or more embodiments of the present disclosure further provide a non-transitory computer-readable storage medium. The storage medium stores computer instructions, and when reading the computer instructions stored in the storage medium, a computer executing the method for vapor-based decolorization of a polyester textile described in the embodiments of the present disclosure.

[0165] Having thus described the basic concepts, it may be rather apparent to those skilled in the art after reading this detailed disclosure that the foregoing detailed disclosure is intended to be presented by way of example only and is not limiting. Various alterations, improvements, and modifications may occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested by this disclosure and are within the spirit and scope of the exemplary embodiments of this disclosure.

[0166] Moreover, certain terminology has been used to describe embodiments of the present disclosure. For example, the terms one embodiment, an embodiment, and/or some embodiments mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, it is emphasized and should be appreciated that two or more references to an embodiment, one embodiment, or an alternative embodiment in various portions of the present disclosure are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined as suitable in one or more embodiments of the present disclosure.

[0167] Furthermore, the recited order of processing elements or sequences, or the use of numbers, letters, or other designations, therefore, is not intended to limit the claimed processes and methods to any order except as may be specified in the claims. Although the above disclosure discusses through various examples what is currently considered to be a variety of useful embodiments of the disclosure, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover modifications and equivalent arrangements that are within the spirit and scope of the disclosed embodiments. For example, although the implementation of various components described above may be embodied in a hardware device, it may also be implemented as a software-only solution, e.g., an installation on an existing server or mobile device.

[0168] Similarly, it should be appreciated that in the foregoing description of embodiments of the present disclosure, various features are sometimes grouped together in a single embodiment, figure, or description thereof to streamline the disclosure aiding in the understanding of one or more of the various inventive embodiments. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed object matter requires more features than are expressly recited in each claim. Rather, inventive embodiments lie in less than all features of a single foregoing disclosed embodiment.

[0169] In some embodiments, the numbers expressing quantities, properties, and so forth, used to describe and claim certain embodiments of the application are to be understood as being modified in some instances by the term about, approximate, or substantially. For example, about, approximate or substantially may indicate 20% variation of the value it describes, unless otherwise stated. Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable.

[0170] Each of the patents, patent applications, publications of patent applications, and other material, such as articles, books, specifications, publications, documents, things, and/or the like, referenced herein is hereby incorporated herein by this reference in its entirety for all purposes, excepting any prosecution file history associated with same, any of same that is inconsistent with or in conflict with the present document, or any of same that may have a limiting effect as to the broadest scope of the claims now or later associated with the present document. By way of example, should there be any inconsistency or conflict between the description, definition, and/or the use of a term associated with any of the incorporated material and that associated with the present document, the description, definition, and/or the use of the term in the present document shall prevail.

[0171] In closing, it is to be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the application. Other modifications that may be employed may be within the scope of the application. Thus, by way of example, but not of limitation, alternative configurations of the embodiments of the application may be utilized in accordance with the teachings herein. Accordingly, embodiments of the present application are not limited to that precisely as shown and described.