Far and near infrared resistant polyester fabric and preparation method thereof

Abstract

The present application relates to a kind of far infrared-proof polyester fabric and its preparation method in the field of polyester fabric production, and the preparation method specifically includes the following steps: polyester is fused first, and 0.01% to 10% of far infrared-proof microparticle is added;The melt polyester is made into spinning solution to spin, and is woven into polyester fabric;The polyester fabric is cleaned after alkali washing and is ready for use, two or more than two kinds of disperse dyes are selected to dye polyester fabric, and the dyeing liquid is circulated in the dyeing device during the dyeing process by centrifugal pump;During the circulation process, the quality of the circulating dyeing liquid of dyeing device is detected, and fixing is carried out after dyeing, realizes the preparation of high-efficiency, accurate far infrared-proof polyester fabric, through circulation dyeing management, real-time dyeing liquid detection, heat exchange unit and step-by-step dyeing method etc., not only improves the preparation efficiency, but also ensures that the reflection performance of fabric in specific infrared band meets the design requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to a polyester fabric and a preparation method thereof, in particular to an anti-far-infrared and near-infrared polyester fabric and a preparation method thereof applied to the field of polyester fabric production. BACKGROUND

[0002] The existing anti-far-infrared and near-infrared polyester fabric technology mainly focuses on developing fibers and coatings with special functions to improve the reflection or absorption capacity of the fabric to infrared rays. These fabrics usually achieve their functions by doping specific metal oxides, carbon-based materials or other infrared reflectors in polyester fibers. For example, the incorporation of materials such as tin oxide or zinc oxide can enhance the reflection performance of the fabric to infrared rays, thereby achieving the effect of preventing infrared detection. In addition, some fabrics use surface coating or lamination technology to apply nanomaterials or special coatings with infrared absorption properties to reduce the transmittance of infrared radiation.

[0003] These technologies not only improve the infrared protection performance of the fabric, but also maintain the original advantages of polyester fabric such as lightness, durability and easy cleaning. In the fields of military, security and privacy protection, this anti-far-infrared and near-infrared polyester fabric has a wide application prospect.

[0004] The specification of Chinese invention patent CN103290703B discloses a processing technology of polyester anti-infrared camouflage printed ribbon, which uses polyester as raw material to achieve the purpose of anti-infrared through dyeing, printing and baking processes; the processing method of the processing technology ensures that the product quality and functionality are both good, the cost of polyester material is lower, the user's cost is reduced, the user is more likely to accept it, and it is also more conducive to the market development and long-term development of the enterprise.

[0005] The specification of Chinese invention patent CN106049092B discloses an anti-infrared military camouflage fabric and its printing and dyeing process, the warp and weft yarns of the camouflage fabric are both cotton-polyester blended yarns, which are blended from cotton fibers, polyester fibers, nylon fibers and silk fibers, and the dyeing process adopts the dispersion bath method of reducing dyes and disperse dyes; the printing process adopts the same paste printing of reducing dyes and disperse dyes; the anti-infrared military camouflage fabric and its printing and dyeing process have the advantages of good anti-infrared camouflage performance, high color fastness, full color, and low cost.

[0006] The existing technology mainly improves the reflection or absorption capacity of the fabric to infrared rays by doping specific metal oxides, carbon-based materials or other infrared reflectors, but does not achieve the ideal infrared band reflectivity, and the dyeing process may have problems such as unstable dye concentration, difficult detection of dye pollution, etc., affecting the quality of the final fabric. SUMMARY

[0007] In view of the prior art, the technical problem to be solved by the present application is that the prior art mainly improves the reflection or absorption capacity of the cloth to infrared rays by doping specific metal oxides, carbon-based materials or other infrared reflectants, but the ideal infrared band reflectivity is not achieved, and the dyeing process may have problems such as unstable dyeing solution concentration, difficult detection of dyeing solution pollution, and the like, which affect the quality of the final cloth.

[0008] To solve the above problems, the present application provides a preparation method of far-infrared and near-infrared resistant polyester cloth, which specifically comprises the following steps:

[0009] S1, melt the polyester and add 0.01%-10% of far-infrared resistant microparticles;

[0010] S2, prepare a spinning solution from the melted polyester and spin it, and then use an air-jet loom to weave the polyester cloth;

[0011] S3, after the polyester cloth is cleaned by alkali washing, it is ready for use, and the alkali washing conditions are 0.4g / L-2g / L of pure alkali and an alkali washing temperature of 80℃;

[0012] S4, prepare a dyeing solution, select two or more than two kinds of disperse dyes to dye the polyester cloth, and match the disperse dyes with the 700nm-1300nm infrared reflectivity curve, with a reflectivity of 10%-70%;

[0013] S5, prepare for dyeing, dissolve the disperse dyes in an organic solvent according to a total concentration of 0.5%-6%, and add an environmentally friendly carrier, a leveling agent and a pH adjuster;

[0014] S6, dyeing, heat to 100-110℃ at a rate of 2℃ / min, keep for 60 minutes, and make the dyeing solution flow in the dyeing device by a centrifugal pump during the dyeing process; during the circulation process, detect the quality of the circulating dyeing solution in the dyeing device, replace the dyeing solution comprehensively when dyeing solution pollutants accumulate, dynamically add new dyeing solution and discharge an equal amount of old dyeing solution, and use the discharged old dyeing solution for preheating of the input new dyeing solution;

[0015] S7, fixation, after dyeing, use sodium hydrosulfite and caustic soda to clean at 80℃ for 15 minutes to remove the floating color and improve the color fastness, and finally perform pickling until the fabric pH is neutral.

[0016] In the above preparation method of far-infrared and near-infrared resistant polyester cloth, efficient and accurate preparation of far-infrared and near-infrared resistant polyester cloth is achieved through circulation dyeing management, real-time dyeing solution detection, heat exchange units and step-by-step dyeing methods.

[0017] As a further improvement of the present application, the dyeing device comprises a dyeing tank and a circulation pipe, the circulation pipe comprises an upper guide tank and a lower guide pipe, a discharge pipe is connected to the upper guide tank and communicates with the centrifugal pump, and a compensation pipe is connected to the upper guide tank and communicates with the dyeing tank.

[0018] The centrifugal pump is installed between the dyeing tank and the circulation pipe, and a main output pipe and a dye liquor detection unit 4 are connected between the centrifugal pump and the dyeing tank, the dye liquor detection unit includes a shunt pipe connected with the main output pipe, and an electrochemical sensor and an optical fiber in-situ sensor are installed in the shunt pipe; the dye liquor detection unit detects the concentration and impurity content of the dye liquor in the process of circulation of the dye liquor.

[0019] As a further improvement of the present application, the dye liquor detection unit includes a sampling analysis structure, the sampling analysis structure includes a detection box arranged outside the shunt pipe, a branch pipe connected with the shunt pipe is arranged in the detection box, at least two sampling tubes are connected to the branch pipe, and a visual detection module and a spectrum detection module matched with the sampling tubes are arranged in the detection box.

[0020] As a further improvement of the present application, a heat exchange unit is installed at the output end of the centrifugal pump, the heat exchange unit includes a main infusion pipe for connecting the centrifugal pump and the circulation pipe, an outer heat exchange shell is sleeved outside the main infusion pipe, a heat exchange pipe is arranged in the outer heat exchange shell and wound around the main infusion pipe, a vice dye liquor tank is connected to the input end of the heat exchange pipe, and the output end of the heat exchange pipe is communicated with a compensation pipe.

[0021] As another improvement of the present application, the vice dye liquor tank is used to prepare compensation dye liquor, and a stirrer and a quantitative feeding device are installed in the vice dye liquor tank.

[0022] As a further improvement of the present application, the disperse dyes include red, yellow, blue, navy blue, black, golden yellow and turquoise blue.

[0023] As a further improvement of the present application, the particle size range of the anti-far infrared microparticles includes 5 nanometers-5 micrometers, and the single fiber fineness of the spun yarn ranges from 0.3 to 1.5 denier.

[0024] As a further improvement of the present application, in the S5 dyeing, low-refractive-index dyes are used to pre-dye to form a base reflection layer, and then high-refractive-index dyes are used for main dyeing.

[0025] An anti-far infrared polyester fabric, the polyester fabric is sprayed with a PU coating.

[0026] In summary, the present application realizes efficient and accurate preparation of anti-far infrared polyester fabric, through circulation dyeing management, real-time dye liquor detection, heat exchange unit and step-by-step dyeing method, not only the preparation efficiency is improved, but also the reflection performance of the fabric in a specific infrared wave band meets the design requirements. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The preparation method flowcharts of the first and second embodiments of the present application;

[0028] Figure 2A perspective view of a dyeing device according to the first and second embodiments of the present application;

[0029] Figure 3 A dye solution circulation path diagram of a dyeing device according to the first and second embodiments of the present application;

[0030] Figure 4 A cross-sectional view of a heat exchange unit according to the second and third embodiments of the present application;

[0031] Figure 5 A cross-sectional view of a dye solution detection unit according to the second and third embodiments of the present application;

[0032] Figure 6 A structure diagram of a dyeing device according to the third embodiment of the present application; Figure 5 A structure diagram of a dyeing device according to the third embodiment of the present application;

[0033] Figure 7 A detection workflow diagram of a dyeing device according to the third embodiment of the present application.

[0034] Explanation of reference numerals in the drawings:

[0035] 1, dyeing tank; 2, circulation pipe; 21, upper guide tank; 22, lower guide pipe; 3, centrifugal pump; 4, spectral detection module; 41, shunt pipe; 42, branch pipe; 43, sampling pipe; 5, heat exchange unit; 51, main liquid delivery pipe; 52, outer heat exchange shell; 53, heat exchange pipe. DETAILED DESCRIPTION

[0036] The five embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0037] First embodiment:

[0038] Figures 1-6 A method for preparing a far-infrared-proof polyester fabric is shown, which specifically comprises the following steps:

[0039] S1, melt the polyester and add 0.01%-10% of far-infrared-proof microparticles; the particle size range of the far-infrared-proof microparticles includes 5 nanometers-5 micrometers; the far-infrared-proof microparticles include one or more of metals, non-metals, metal oxides, or metal compounds, specifically including nickel, zirconium, titanium, zinc, silver, aluminum, silicon, copper, carbon, nitrogen, and sulfur; the appropriate microparticles are selected and added by those skilled in the art as needed;

[0040] The microparticles are added by those skilled in the art using an appropriate microparticle addition method in the prior art, such as a pre-dispersed master batch method and an in-situ polymerization dispersion method;

[0041] S2, melt the polyester into a spinning solution, and then spin and weave using an air-jet loom to obtain a polyester fabric; the single fiber fineness of the spun fabric ranges from 0.3 to 1.5 denier; the warp and weft yarns used in air-jet weaving are combined in a 50D / 72FFDY x 50D / 72F FDY combination, the weaving density is 185 x 107, and the fabric weight is 60-70 g / m 2 ;

[0042] S3, the polyester fabric is cleaned by alkali washing, the alkali washing conditions are 0.4 g / L-2 g / L of pure alkali, and the alkali washing temperature is 80°C;

[0043] S4, dye solution preparation, two or more than two kinds of disperse dyes are selected for dyeing the polyester fabric, the disperse dyes match the 700 nm-1300 nm infrared reflectivity curve, and the reflectivity is 10%-70%; the disperse dyes include red, yellow, blue, navy blue, black, golden yellow, and turquoise blue;

[0044] S5, preparation for dyeing, dissolving the disperse dyes in an organic solvent at a total concentration of 0.5%-6%, adding an environmentally friendly carrier, a leveling agent, and a pH adjuster, and the environmentally friendly carrier includes modified lignin sulfonate;

[0045] S6, dyeing, heating to 100-110°C at a rate of 2°C / min, and maintaining the temperature for 60 minutes; the final color of the dyeing matches the target color, i.e., matches the core parameters of the CIELAB color space of the target color, including lightness, red-green axis, yellow-blue axis, chroma, and hue angle, and the reflectivity curve of the fabric in the 700 nm-1300 nm wavelength region deviates from the environmental target value by less than 5%;

[0046] During the dyeing process, the dyeing device is circulated by a centrifugal pump 3; during the circulation, the quality of the circulating dyeing solution is detected, and the dye concentration is detected in real time by a miniature spectrometer or an optical fiber sensor at a dye solution detection unit 4;

[0047] When dyeing solution pollutants are detected (i.e., when heavy metal content is too high or organic pollution is serious), the dyeing solution is completely replaced;

[0048] When the dyeing solution is completely replaced: first, the dyeing solution is cooled to below 90°C at a rate of 2°C / min, and then the old solution in the dyeing tank 1 is emptied; then, hot water at 80°C is circulated for 5 minutes to remove residual dyes and oligomers; the preheated new dyeing solution is injected into the dyeing tank 1; finally, the centrifugal pump 3 is restarted, and the flow rate and pressure are adjusted to meet the process requirements;

[0049] When the dye concentration is lower than the set value, new dye liquor is dynamically added and an equal amount of old dye liquor is discharged, and the discharged old dye liquor is used for preheating the input new dye liquor; for example, when the dye concentration in the dye liquor is lower than 1 g / L, new dye liquor is supplemented to maintain the dyeing depth; if the concentration is still higher than 1 g / L, the dye liquor can be directly recycled for 4-6 times, and only a small amount of deionized water needs to be supplemented each time;

[0050] The specific operation of dynamically adding dye liquor includes: gradually adding preheated new dye liquor at a ratio of 20%-30% each time, that is, the amount of new dye liquor injected each time is 20%-30% of the amount of old dye liquor in the dyeing tank 1, and an equal amount of old liquor is discharged when the new dye liquor is injected; when the new dye liquor is added, the centrifugal pump 3 is controlled to work, the flow rate of the circulating dye liquor is kept ≥25 L / (kg·min), and the uniform mixing of the new and old dye liquors is ensured; after the new dye liquor is injected each time and uniformly mixed, the dye concentration is detected; if the dye concentration is still lower than the set value, the above new dye liquor injection operation is repeated; if the dye concentration is higher than the set value, the new dye liquor injection is stopped;

[0051] S7, fixing, after dyeing, using sodium hydrosulfite and caustic soda at 80℃ for 15 minutes to remove the floating color and improve the color fastness, and finally washing the fabric to neutral pH to obtain the finished fabric.

[0052] The embodiment realizes efficient preparation of the far-infrared and near-infrared resistant polyester fabric, which not only effectively blocks far-infrared radiation, but also has certain protection ability to near-infrared light. Through the fine preparation process, especially the accurate dye selection and the circulation dyeing management in the steps S4 to S6, the reflectivity of the fabric in a specific infrared wave band meets the design requirements, thereby improving the comprehensive protection performance of the fabric.

[0053] The second embodiment:

[0054] Figures 2-7 It is shown that the dyeing device includes a dyeing tank 1 and a circulation pipe 2, the circulation pipe 2 includes an upper guide tank 21 and a lower guide pipe 22, the lower guide pipe 22 is connected with a liquid discharge pipe and communicates with a centrifugal pump 3, and the liquid discharge pipe is used for discharging old dye liquor;

[0055] The upper guide tank 21 is connected with a compensation pipe and communicates with the dyeing tank 1; a heater is installed in the upper guide tank 21; and the compensation pipe is used for inputting new dye liquor;

[0056] The centrifugal pump 3 is installed between the dyeing tank 1 and the circulation pipe 2, and the centrifugal pump 3 is connected with the dyeing tank 1 through a main output pipe and a dye liquor detection unit 4; the dye liquor detection unit 4 includes a shunt pipe 41 connected with the main output pipe, and an electrochemical sensor and an optical fiber in-situ sensor are installed in the shunt pipe 41; the dye liquor detection unit 4 detects the dye concentration and the impurity content in the process of circulating the dye liquor;

[0057] The dye solution detection unit 4 comprises a sampling analysis structure, which comprises a detection box arranged outside the shunt pipe 41, the detection box is provided with a branch pipe 42 connected with the shunt pipe 41, the branch pipe 42 is connected with at least two sampling tubes 43, the sampling tubes 43 are made of transparent material, and the opening and closing of the sampling tubes 43 and the branch pipe 42 are realized by the electromagnetic valves in the prior art;

[0058] One end of the sampling tube 43 is communicated with the branch pipe 42, and the other end is connected with a one-way valve, the one-way valve is connected with a cleaning liquid input pipe; when the old dye solution is discharged, the sampling tube 43 discharges the sampled dye solution, and at the same time, the cleaning liquid is injected through the one-way valve to clean the sampling tube 43 and the branch pipe 42, so that the sampling tube 43 is cleaned synchronously when the old dye solution is discharged.

[0059] The detection box is provided with a visual detection module and a spectrum detection module matched with the sampling tube 43, and the visual detection module and the spectrum detection module detect the two sampling tubes 43 respectively.

[0060] When the dye solution circulates, part of the dye solution is shunted to the dye solution detection unit 4, and the dye solution is detected in real time by the electrochemical sensor and the optical fiber in-situ sensor in the shunt pipe 41 to preliminarily detect the heavy metal content and the dye concentration; if the detection value reaches the set early warning value or reaches the set sampling inspection time point, the sampling analysis structure is controlled to work, so that the branch pipe 42 is opened, at this time, the dye solution fills the branch pipe 42, at this time, the spectrum detection module detects the dye concentration and the heavy metal content, the visual detection module collects images, and then the turbidity change is analyzed by the HSV color model to judge the organic pollution condition; the visual detection module and the spectrum detection module adopt the prior art, and the appropriate spectrum detection equipment and visual detection equipment in the prior art are selected and installed by the person skilled in the art;

[0061] If the heavy metal content is greater than the set value or the organic pollution condition exceeds the set standard, the dye solution is replaced in an all-round way;

[0062] The dye solution detection unit 4 of the embodiment realizes real-time monitoring of the dye solution concentration and rapid analysis of the impurity content. In the dye solution circulation process, the electrochemical sensor can sensitively detect the impurity content such as heavy metal ions in the dye solution, so as to ensure that the dye solution quality meets the production requirements. At the same time, the optical fiber in-situ sensor accurately measures the dye concentration to maintain the concentration stability in the dyeing process. When the detection value reaches the preset early warning value, the system automatically triggers the sampling analysis structure, the dye solution sample is collected through the branch pipe 42, and further in-depth analysis is carried out by using the spectrum detection module and the visual detection module, so as to effectively judge the organic pollution condition. This series of detection and analysis measures not only improves the accuracy of dyeing, but also effectively guarantees the quality and performance of the final fabric product.

[0063] The third embodiment:

[0064] Figures 3-7 As shown, the output end of the centrifugal pump 3 is provided with a heat exchange unit 5, which comprises a main liquid conveying pipe 51 for connecting the centrifugal pump 3 and the circulation pipe 2, and an outer heat exchange shell 52 sleeved outside the main liquid conveying pipe 51, and a heat exchange pipe 53 is arranged in the outer heat exchange shell 52 and wound around the main liquid conveying pipe 51, the input end of the heat exchange pipe 53 is connected with a secondary dye tank, and the output end of the heat exchange pipe 53 is communicated with a compensation pipe; the secondary dye tank is used for preparing compensation dye, and a stirrer and a quantitative feeding device are arranged in the secondary dye tank.

[0065] When the new dye is preheated in the overall dye replacement operation, the dye tank 1 is filled with new dye, and at the same time, 80° hot water is input into the outer heat exchange shell 52 (after the hot water is heated and output from the outer heat exchange shell 52, the discharged hot water can be heated again and injected into the dyeing tank 1 for cleaning), so that the new dye in the heat exchange pipe 53 is preheated by the hot water in the outer heat exchange shell 52, and after the preheated new dye is input into the upper guide tank 21, the new dye can be further heated to a specified temperature by a heater, and then injected into the dyeing tank 1;

[0066] When the new dye is preheated in the overall dye replacement operation, the dye tank 1 is filled with new dye, and at the same time, 80° hot water is input into the outer heat exchange shell 52 (after the hot water is heated and output from the outer heat exchange shell 52, the discharged hot water can be heated again and injected into the dyeing tank 1 for cleaning), so that the new dye in the heat exchange pipe 53 is preheated by the hot water in the outer heat exchange shell 52, and after the preheated new dye is input into the upper guide tank 21, the new dye can be further heated to a specified temperature by a heater, and then injected into the dyeing tank 1;

[0067] The heat exchange unit 5 of the embodiment realizes effective preheating of the new dye and full utilization of the residual heat of the old dye. When the dye is replaced, the new dye is preheated in the hot water in the outer heat exchange shell 52 through the heat exchange pipe 53, which increases the temperature of the new dye and reduces the energy required for subsequent heating, thereby saving energy. In the process of dynamically adding dye, the residual heat of the old dye is absorbed by the new dye in the heat exchange pipe 53 when the old dye flows out of the main liquid conveying pipe 51, thereby realizing effective recovery and reuse of energy and further improving energy utilization efficiency.

[0068] The fourth embodiment:

[0069] S5, a low-refractive-index dye is used to pre-dye to form a base reflection layer, for example, yellow dye, and the pre-dyeing temperature is 115°C;

[0070] After the pre-dyeing is completed, the dye in the dyeing tank 1 is replaced with dye of high-refractive-index dye for superimposed main dyeing according to the overall dye replacement operation in the first embodiment or the third embodiment.

[0071] High refractive index dyes such as: navy blue and black dyes, gradient warming to 130°C, and holding, main dyeing to the desired color;

[0072] The present embodiment effectively improves the reflection performance of the polyester fabric in a specific infrared wave band by first using low refractive index dyes to pre-dye the base reflection layer and then superimposing high refractive index dyes for main dyeing. This step-by-step dyeing method not only enhances the anti-near-infrared and anti-far-infrared capabilities of the fabric, but also makes the color of the final product more uniform and has higher color fastness. In addition, this embodiment also retains the advantages of the previous embodiments, such as cycle dyeing management, precise dye concentration control, and efficient energy utilization, etc., thereby ensuring efficient preparation and excellent performance of the anti-near-infrared and anti-far-infrared polyester fabric.

[0073] The fifth embodiment:

[0074] S6 The dyed polyester fabric is subjected to PU spraying, and the polyester fabric is sprayed with a PU coating layer. The PU coating layer technology of the prior art is used, and the PU coating layer is sprayed at a rate of 0.5g / m 2 The PU coating layer is capped, and the formed anti-near-infrared and anti-far-infrared polyester fabric has both infrared resistance and electrical conductivity.

[0075] The anti-near-infrared and anti-far-infrared polyester fabric of the present embodiment realizes the combination of efficient protection and multifunctionality. Through the introduction of the PU coating layer, not only the protection capability of the fabric against near-infrared and far-infrared light is further enhanced, but also the fabric is endowed with good electrical conductivity, thereby widening its application scenarios.

[0076] In summary, the present scheme realizes efficient and precise preparation of anti-near-infrared and anti-far-infrared polyester fabric. Through cycle dyeing management, real-time dye solution detection, heat exchange unit 5, and step-by-step dyeing method, etc., not only the preparation efficiency is improved, but also the reflection performance of the fabric in a specific infrared wave band meets the design requirements.

[0077] In combination with the current actual needs, the above-mentioned embodiments adopted by the present application do not limit the scope of protection, and various changes made within the knowledge of those skilled in the art without departing from the concept of the present application still fall within the protection scope of the present application.

Claims

1. A method for preparing a polyester fabric with near-infrared and far-infrared protection, characterized in that: Specifically, the following steps are included: S1, melt polyester and add 0.01%-10% far-infrared blocking particles; S2, molten polyester is made into a spinning solution for spinning, and then woven using an air-jet loom to obtain polyester fabric; S3, polyester fabric is washed with alkali and set aside. The alkali washing conditions are 0.4g / L-2g / L soda ash and the alkali washing temperature is 80℃. S4, dye liquor preparation, select two or more disperse dyes to dye polyester fabric, the disperse dyes are matched with the 700nm-1300nm infrared reflectance curve, and the reflectance is 10%-70%. S5, prepare for dyeing. Dissolve disperse dyes in an organic solvent at a total concentration of 0.5%-6%, and add an environmentally friendly carrier, leveling agent, and pH adjuster. First, use low-refractive-index dyes to pre-dye to form a base reflective layer, and then layer high-refractive-index dyes for main dyeing. S6, dyeing, heating to 100-110℃ at 2℃ / min, holding for 60 minutes, and circulating the dye solution in the dyeing device through a centrifugal pump (3) during the dyeing process; during the circulation process, the dye solution is detected in real time, and the heavy metal content and dye concentration are initially detected. When the dye concentration is lower than the set value, it is first determined whether the heavy metal content has reached the set warning value. If so, a sample of dye solution is collected to detect the dye concentration and heavy metal content. Otherwise, new dye solution is added dynamically. If the heavy metal content of the dye solution sample is greater than the set value or the organic pollution exceeds the set standard, the dye solution is completely replaced. Otherwise, new dye solution is added dynamically. When adding new dye solution dynamically, an equal amount of old dye solution is discharged. The discharged old dye solution is used for the preheating of the new dye solution. S7, color fixation: After dyeing, wash with sodium hydrosulfite and caustic soda at 80℃ for 15 minutes to remove floating color and improve color fastness. Finally, acid wash until the fabric pH is neutral.

2. The method for preparing a far- and near-infrared resistant polyester fabric according to claim 1, characterized in that: The dyeing device includes a dyeing tank (1) and a circulation pipe (2). The circulation pipe includes an upper guide tank (21) and a lower guide pipe (22). The lower guide pipe (22) is connected to a drain pipe and communicates with a centrifugal pump (3). The upper guide tank (21) is connected to a compensation pipe and communicates with the dyeing tank (1). The centrifugal pump (3) is installed between the dyeing tank (1) and the circulation pipe (2), and the centrifugal pump (3) and the dyeing tank (1) are connected by a main output pipe and a dye liquor detection unit (4). The dye liquor detection unit (4) includes a diversion pipe (41) connected to the main output pipe. An electrochemical sensor and an optical fiber in-situ sensor are installed in the diversion pipe (41). The dye liquor detection unit (4) detects the dye liquor concentration and impurity content during the dye liquor circulation process.

3. The method for preparing a far- and near-infrared resistant polyester fabric according to claim 2, characterized in that: The dye solution detection unit (4) includes a sampling analysis structure, which includes a detection box located outside the diversion tube (41). The detection box contains a branch tube (42) connected to the diversion tube (41). At least two sampling tubes (43) are connected to the branch tube (42). The detection box contains a visual detection module and a spectral detection module that match the sampling tubes (43).

4. The method for preparing a far- and near-infrared resistant polyester fabric according to claim 1, characterized in that: The output end of the centrifugal pump (3) is equipped with a heat exchange unit (5). The heat exchange unit (5) includes a main infusion pipe (51) for connecting the centrifugal pump (3) and the circulation pipe (2). An outer heat exchange shell (52) is sleeved on the outside of the main infusion pipe (51). A heat exchange tube (53) wound around the main infusion pipe (51) is inserted inside the outer heat exchange shell (52). The input end of the heat exchange tube (53) is connected to a secondary dyeing tank. The output end of the heat exchange tube (53) is connected to a compensation pipe.

5. The method for preparing a far- and near-infrared resistant polyester fabric according to claim 4, characterized in that: The auxiliary dyeing solution tank is used to prepare and compensate for the dyeing solution. The auxiliary dyeing solution tank is equipped with a stirrer and a quantitative feeding device.

6. The method for preparing a far- and near-infrared resistant polyester fabric according to claim 1, characterized in that: The disperse dyes include red, yellow, blue, navy blue, black, golden yellow, and turquoise.

7. The method for preparing a far- and near-infrared resistant polyester fabric according to claim 1, characterized in that: The particle size range of the far-infrared protection microparticles includes 5 nanometers to 5 micrometers, and the fineness of the single fiber of the spun yarn ranges from 0.3 to 1.5 denier.

8. A far- and near-infrared resistant polyester fabric obtained by the preparation method according to any one of claims 1-7, characterized in that: The polyester fabric is coated with a PU coating.

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