A method for preparing an antibacterial filter cloth

Abstract

This application relates to the field of filter cloth, specifically disclosing a method for preparing an antibacterial filter cloth, comprising the following steps: S1. Mixing 10-13 parts by weight of tourmaline powder and 5-8 parts by weight of chitosan into 50-60 parts by weight of an aqueous acetic acid solution, stirring and mixing for 15-20 minutes to obtain an impregnation solution; S2. Immersing polyamide fibers in the impregnation solution, then removing them and drying them at 30-40°C, and then arranging the warp and weft threads of the treated polyamide fibers to weave a web to obtain a filter cloth; Chitosan has antibacterial properties, which can improve the antibacterial effect of the filter cloth; Tourmaline powder can emit far-infrared rays, which inhibits the growth activity of bacteria and helps to improve the antibacterial effect of chitosan; After dissolving, chitosan forms a gel state with a certain viscosity, which can increase the bonding force between tourmaline powder and polyamide fibers, inhibit the shedding of tourmaline powder, delay the decay of the antibacterial effect of the filter cloth, and improve the durability of the antibacterial effect of the filter cloth.

Description

Technical Field

[0001] This application relates to the field of filter cloth, and more specifically, it relates to a method for preparing an antibacterial filter cloth. Background Technology

[0002] Filter cloth is a filter medium woven from natural or synthetic fibers. It is mainly used for air filtration and solid-liquid separation to purify air and separate substances. It is widely used in metallurgy, chemical industry, medicine, food and other fields.

[0003] During use, filter cloth inevitably comes into contact with various substances or pharmaceutical solutions. After prolonged use, bacteria and fungi inevitably accumulate on the filter cloth. The growth of bacteria and fungi affects the subsequent filtration effect of the filter cloth and may lead to microbial contamination of the filtered substances, which needs to be improved. Summary of the Invention

[0004] To improve the antibacterial effect of filter cloth, this application provides a method for preparing antibacterial filter cloth.

[0005] The method for preparing an antibacterial filter cloth provided in this application adopts the following technical solution:

[0006] A method for preparing an antibacterial filter cloth includes the following steps:

[0007] S1. Mix 10-13 parts by weight of tourmaline powder and 5-8 parts by weight of chitosan and add them to 50-60 parts by weight of acetic acid aqueous solution. Stir and mix for 15-20 minutes to obtain impregnation solution.

[0008] S2. Immerse the polyamide fibers in the impregnation solution, then remove them and dry them at 30-40℃. Then arrange the warp and weft threads of the treated polyamide fibers and weave them into a mesh to obtain the filter cloth.

[0009] By adopting the above technical solution, chitosan has antibacterial properties. Coating it onto the surface of polyamide fibers can improve the antibacterial effect of the filter cloth. Tourmaline powder can emit far-infrared rays, which can penetrate the bacteria attached to the filter cloth, thereby heating the bacteria for a long time and inhibiting their growth activity. This helps to improve the antibacterial effect of chitosan. After dissolving, chitosan forms a gel with a certain viscosity, which can adhere tourmaline powder to the surface of polyamide fibers, increase the bonding force between tourmaline powder and polyamide fibers, inhibit the shedding of tourmaline powder, delay the decay of the antibacterial effect of the filter cloth, and improve the durability of the antibacterial effect of the filter cloth.

[0010] Preferably, in step S2, the polyamide fiber is placed on the sieve plate above the reaction tube in the hydrothermal reactor, and 1-2 wt% HF solution is added below the sieve plate. After sealing the hydrothermal reactor, it is transferred to an oven and hydrothermally reacted at 90-100°C for 1-2 hours. Then, the polyamide fiber is immersed in the impregnation solution.

[0011] By adopting the above technical solution, the polyamide fibers undergo moderate corrosion under the etching effect of the HF atmosphere, achieving the purpose of expanding and creating pores and forming a layered pore structure. This roughens the surface of the polyamide fibers. After subsequent immersion in the impregnation solution and drying and weaving, the polyamide fibers in the filter cloth are squeezed against each other, causing tourmaline powder to be trapped in the concave pores on the surface of the polyamide fibers and increasing the friction between the tourmaline powder and the surface of the polyamide fibers. This reduces the occurrence of tourmaline powder falling off the surface of the polyamide fibers under the impact of the flowing liquid during use, and can further improve the durability of the antibacterial effect of the filter cloth.

[0012] Preferably, in step S2, the polyamide fiber is immersed in the impregnation solution, then taken out and dried at 30-40°C. Next, the polyamide fiber and wool fiber are twisted in a spiral to obtain a blended yarn. Then, the blended yarn is arranged with warp and weft threads and woven into a web to obtain a filter cloth.

[0013] By adopting the above technical solution, wool fibers have felting properties. Adding wool fibers to the filter cloth can gradually increase the density of the filter cloth during repeated use, making the contact between tourmaline powder and polyamide fibers closer and the contact area larger, increasing the frictional resistance between tourmaline powder and polyamide fibers. At the same time, it is easier to press the tourmaline powder into the pores on the surface of the polyamide fibers, reducing the loss of tourmaline powder and improving the antibacterial effect of the filter cloth.

[0014] Preferably, in step S2, after the hydrothermal reaction for 1-2 hours, the polyamide fiber is immersed in purple cabbage extract for 20-30 minutes, then dried at 60-70°C, and then immersed in the impregnation solution again, and then dried at 30-40°C.

[0015] By adopting the above technical solution, the purple cabbage extract contains a large amount of anthocyanins, and the cell wall components of microorganisms contain lipopolysaccharides. When the cells are in an unfavorable external environment, lipopolysaccharides play a protective role for the cells. Anthocyanins can destroy the structure of lipopolysaccharides, causing the cell wall of microorganisms to permeate, thereby destroying the structure of microorganisms, inhibiting bacterial reproduction, and improving the antibacterial effect of the filter cloth.

[0016] Preferably, the method for preparing the purple cabbage extract is as follows: pulverize the purple cabbage, then add 70-90 (v / v)% ethanol solution, stir and mix evenly, the weight ratio of purple cabbage to ethanol solution is 1:(6-8), heat the resulting mixture at 50-70℃ for 2-4 hours, allow it to stand and separate into layers, take the supernatant to obtain the purple cabbage extract.

[0017] Preferably, in step S2, the polyamide fiber is immersed in purple cabbage extract for 20-30 minutes, then dried at 60-70°C. Next, sodium alginate aqueous solution is sprayed onto the surface of the polyamide fiber, and then dried at 60-70°C. Then, the polyamide fiber is immersed in the impregnation solution, and then dried at 30-40°C.

[0018] By adopting the above technical solution, sodium alginate aqueous solution is used to lock the purple cabbage extract onto the polyamide fiber, thereby improving the adhesion and shaping effect of the purple cabbage extract on the polyamide fiber, delaying the loss of purple cabbage extract during the use of the filter cloth, and improving the durability of the antibacterial effect of the filter cloth.

[0019] Preferably, in step S2, after spraying the surface of the polyamide fiber with an aqueous solution of sodium alginate, the fiber is left to stand for 20-30 minutes, rinsed with deionized water, and then dried at 60-70°C.

[0020] By adopting the above technical solution, sodium alginate aqueous solution is promoted to penetrate polyamide fiber, thereby locking purple cabbage extract inside the polyamide fiber. At the same time, excess sodium alginate aqueous solution on the surface of polyamide fiber is flushed away, so as to expose the surface of polyamide fiber and allow the surface of polyamide fiber to come into contact with tourmaline powder.

[0021] In summary, this application has the following beneficial effects:

[0022] 1. Since this application uses chitosan, tourmaline powder and polyamide fiber, chitosan has antibacterial properties, which can improve the antibacterial effect of the filter cloth. Tourmaline powder can emit far-infrared rays, which can inhibit the growth activity of bacteria and help improve the antibacterial effect of chitosan. After the chitosan is dissolved, it forms a gel with a certain viscosity, which can increase the binding force between tourmaline powder and polyamide fiber, inhibit the shedding of tourmaline powder, delay the decay of the antibacterial effect of the filter cloth, and improve the durability of the antibacterial effect of the filter cloth.

[0023] 2. In this application, HF solution is preferably used. Under the etching effect of HF atmosphere, the polyamide fiber is moderately corroded, which achieves the purpose of expanding and creating pores, making the surface of the polyamide fiber rough. This allows tourmaline powder to be stuck in the concave pores on the surface of the polyamide fiber and increases the friction between the tourmaline powder and the surface of the polyamide fiber, reducing the loss of tourmaline powder during use and further improving the durability of the antibacterial effect of the filter cloth.

[0024] 3. In this application, wool fiber is preferred. Wool fiber has a felting property. Adding wool fiber to the filter cloth can gradually increase the density of the filter cloth during repeated use, increase the frictional resistance between tourmaline powder and polyamide fiber, and at the same time facilitate the tourmaline powder to be pressed into the pores on the surface of polyamide fiber, reduce the loss of tourmaline powder, and improve the antibacterial effect of the filter cloth. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments.

[0026] Information source Acetic acid aqueous solution 5 (v / v)% acetic acid aqueous solution Tourmaline powder Mesh number: 1250 mesh polyamide fiber Grade: 70G13HS1L; Model: 11C1-40 ethanol solution 50 (v / v)% ethanol solution Sodium alginate aqueous solution 5wt% sodium alginate aqueous solution Sodium stearate aqueous solution 5wt% sodium stearate aqueous solution

[0027] It should be noted that (v / v)% refers to volume percentage.

[0028] Unless otherwise specified, all raw materials used in the following embodiments are commercially available.

[0029] Example of raw material preparation

[0030] Preparation Example 1

[0031] The method for preparing purple cabbage extract is as follows: crush purple cabbage, pass it through a 5-mesh sieve, then add 70 (v / v)% ethanol solution, stir and mix evenly, the weight ratio of purple cabbage to ethanol solution is 1:6, heat the resulting mixture at 50℃ for 4 hours, let it stand to separate into layers, take the supernatant to obtain purple cabbage extract.

[0032] Preparation Example 2

[0033] The preparation method of purple cabbage extract is as follows: crush purple cabbage, pass it through a 5-mesh sieve, then add 90 (v / v)% ethanol solution, stir and mix evenly, the weight ratio of purple cabbage to ethanol solution is 1:8, heat the obtained product at 70℃ for 2 hours, let it stand to separate into layers, take the supernatant to obtain purple cabbage extract.

[0034] Preparation Example 3

[0035] The method for preparing purple cabbage extract is as follows: crush purple cabbage, pass it through a 5-mesh sieve, then add 80 (v / v)% ethanol solution, stir and mix evenly, the weight ratio of purple cabbage to ethanol solution is 1:7, heat the resulting mixture at 60℃ for 3 hours, let it stand to separate into layers, take the supernatant to obtain purple cabbage extract.

[0036] Preparation Example 4

[0037] The method for preparing cabbage extract is as follows: crush cabbage, pass it through a 5-mesh sieve, then add 70 (v / v)% ethanol solution, stir and mix evenly, the weight ratio of cabbage to ethanol solution is 1:6, heat the resulting mixture at 50℃ for 4 hours, let it stand to separate into layers, take the supernatant to obtain cabbage extract.

[0038] Example

[0039] Example 1

[0040] This application discloses a method for preparing an antibacterial filter cloth, comprising the following steps:

[0041] S1. Mix 10 parts by weight of tourmaline powder and 5 parts by weight of chitosan into 50 parts by weight of acetic acid aqueous solution, stir and mix for 15 minutes to obtain impregnation solution;

[0042] S2. Immerse the polyamide fiber in the impregnation solution, then take it out and dry it at 30°C. Then arrange the warp and weft of the treated polyamide fiber to weave a mesh to obtain the filter cloth.

[0043] Example 2

[0044] This application discloses a method for preparing an antibacterial filter cloth, comprising the following steps:

[0045] S1. Mix 13 parts by weight of tourmaline powder and 8 parts by weight of chitosan into 60 parts by weight of acetic acid aqueous solution, stir and mix for 20 minutes to obtain impregnation solution;

[0046] S2. Immerse the polyamide fibers in the impregnation solution, then remove them and dry them at 40°C. Then arrange the warp and weft threads of the treated polyamide fibers and weave them into a mesh to obtain the filter cloth.

[0047] Example 3

[0048] This application discloses a method for preparing an antibacterial filter cloth, comprising the following steps:

[0049] S1. Mix 12 parts by weight of tourmaline powder and 7 parts by weight of chitosan into 55 parts by weight of acetic acid aqueous solution, stir and mix for 18 minutes to obtain impregnation solution;

[0050] S2. Immerse the polyamide fibers in the impregnation solution, then remove them and dry them at 35°C. Then arrange the warp and weft threads of the treated polyamide fibers and weave them into a mesh to obtain the filter cloth.

[0051] Example 4

[0052] The difference from Example 1 is that in step S2, the polyamide fiber is placed on the sieve plate above the reaction tube in the hydrothermal reactor, and 1 wt% HF solution is added below the sieve plate. After sealing the hydrothermal reactor, it is transferred to an oven and hydrothermally reacted at 90°C for 2 hours. Then, the polyamide fiber is immersed in the impregnation solution, and then taken out and dried at 30°C. Next, the treated polyamide fiber is arranged with warp and weft threads and woven into a mesh to obtain the filter cloth.

[0053] Example 5

[0054] The difference from Example 4 is that in step S2, the polyamide fiber is immersed in the impregnation solution, then taken out and dried at 30°C. Then, the polyamide fiber and wool fiber with a mass ratio of 3:1 are twisted in a spiral to obtain a blended yarn. The blended yarn is then arranged with warp and weft threads and woven into a web to obtain a filter cloth.

[0055] Example 6

[0056] The difference from Example 4 is that in step S2, the polyamide fiber is placed on the sieve plate above the reaction tube in the hydrothermal reactor, and 1 wt% HF solution is added below the sieve plate. After sealing the hydrothermal reactor, it is transferred to an oven and hydrothermally reacted at 90°C for 2 hours. Then, the polyamide fiber is immersed in purple cabbage extract for 20 minutes, taken out and dried at 60°C. The polyamide fiber is then immersed in the impregnation solution, taken out and dried at 30°C. Finally, the treated polyamide fiber is arranged with warp and weft threads and woven into a mesh to obtain the filter cloth.

[0057] In this embodiment, the purple cabbage extract was prepared in Preparation Example 1.

[0058] Example 7

[0059] The difference from Example 6 is that in step S2, the polyamide fiber is placed on the sieve mesh above the reaction tube in the hydrothermal reactor, and 1 wt% HF solution is added below the sieve mesh. After sealing the hydrothermal reactor, it is transferred to an oven and hydrothermally reacted at 90°C for 2 hours. Then, the polyamide fiber is immersed in purple cabbage extract for 20 minutes, taken out and dried at 60°C. Then, sodium alginate aqueous solution is sprayed on the surface of the polyamide fiber and dried at 60°C. Next, the polyamide fiber is immersed in the impregnation solution and then taken out and dried at 30°C.

[0060] Example 8

[0061] The difference from Example 7 is that in step S2, after spraying sodium alginate aqueous solution onto the surface of the polyamide fiber, it is left to stand for 20 minutes, rinsed with deionized water, and then dried at 60°C.

[0062] Example 9

[0063] This application discloses a method for preparing an antibacterial filter cloth, comprising the following steps:

[0064] S1. Mix 10 parts by weight of tourmaline powder and 5 parts by weight of chitosan into 50 parts by weight of acetic acid aqueous solution, stir and mix for 15 minutes to obtain impregnation solution;

[0065] S2. Place polyamide fibers on the sieve plate above the reaction tube in the hydrothermal reactor. Add 1 wt% HF solution below the sieve plate. Seal the hydrothermal reactor and transfer it to an oven. Perform a hydrothermal reaction at 90°C for 2 hours. Then, immerse the polyamide fibers in purple cabbage extract for 20 minutes. Remove and dry at 60°C. Spray the surface of the polyamide fibers with sodium alginate solution and let stand for 20 minutes. Rinse with deionized water and dry at 60°C. Next, immerse the polyamide fibers in the impregnation solution and dry at 30°C. Then, twist polyamide fibers and wool fibers in a 3:1 mass ratio in a spiral to obtain a blended yarn. Arrange the warp and weft of the blended yarn and weave it into a mesh to obtain a filter cloth.

[0066] In this embodiment, the purple cabbage extract was prepared in Preparation Example 1.

[0067] Example 10

[0068] This application discloses a method for preparing an antibacterial filter cloth, comprising the following steps:

[0069] S1. Mix 13 parts by weight of tourmaline powder and 8 parts by weight of chitosan into 60 parts by weight of acetic acid aqueous solution, stir and mix for 20 minutes to obtain impregnation solution;

[0070] S2. Place polyamide fibers on the sieve plate above the reaction tube in the hydrothermal reactor. Add 2wt% HF solution below the sieve plate. Seal the hydrothermal reactor and transfer it to an oven. Perform a hydrothermal reaction at 100℃ for 1 hour. Then, immerse the polyamide fibers in purple cabbage extract for 30 minutes. Remove and dry at 70℃. Spray the surface of the polyamide fibers with sodium alginate solution and let stand for 30 minutes. Rinse with deionized water and dry at 70℃. Next, immerse the polyamide fibers in the impregnation solution and dry at 40℃. Then, twist polyamide fibers and wool fibers in a 3:1 mass ratio in a spiral to obtain a blended yarn. Arrange the warp and weft of the blended yarn and weave it into a mesh to obtain a filter cloth.

[0071] In this embodiment, the purple cabbage extract was prepared in Preparation Example 2.

[0072] Example 11

[0073] This application discloses a method for preparing an antibacterial filter cloth, comprising the following steps:

[0074] S1. Mix 12 parts by weight of tourmaline powder and 7 parts by weight of chitosan into 55 parts by weight of acetic acid aqueous solution, stir and mix for 18 minutes to obtain impregnation solution;

[0075] S2. Place polyamide fibers on the sieve plate above the reaction tube in the hydrothermal reactor. Add 1 wt% HF solution below the sieve plate. Seal the hydrothermal reactor and transfer it to an oven. Perform a hydrothermal reaction at 95°C for 1 hour. Then, immerse the polyamide fibers in purple cabbage extract for 25 minutes. Remove and dry at 65°C. Spray the surface of the polyamide fibers with sodium alginate solution and let stand for 25 minutes. Rinse with deionized water and dry at 65°C. Next, immerse the polyamide fibers in the impregnation solution and remove and dry at 35°C. Then, twist polyamide fibers and wool fibers in a 3:1 mass ratio in a spiral to obtain a blended yarn. Arrange the warp and weft of the blended yarn and weave it into a mesh to obtain a filter cloth.

[0076] In this embodiment, the purple cabbage extract was prepared in Preparation Example 3.

[0077] Example 12

[0078] The difference from Example 5 is that the wool fibers are replaced with rabbit hair fibers.

[0079] Example 13

[0080] The difference from Example 6 is that the purple cabbage extract was replaced with cabbage extract, which was prepared in Preparation Example 4.

[0081] Example 14

[0082] The difference from Example 7 is that the sodium alginate aqueous solution is replaced with a sodium stearate aqueous solution.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] The difference from Example 1 is that the filter cloth obtained by weaving a web using polyamide fibers as warp and weft is used as a blank control group.

[0086] Comparative Example 2

[0087] The difference from Example 1 is that tourmaline powder is replaced with mica powder.

[0088] Performance testing

[0089] (1) Antibacterial performance test (characterized by inhibition rate): The antibacterial performance of Examples 1-14 and Comparative Examples 1-2 was tested according to the standard GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method". The test strain was Staphylococcus aureus. The test results are shown in Table 1 below.

[0090] (2) Durability test of antibacterial properties (characterized by inhibition rate): The filter cloths of Examples 1-14 and Comparative Examples 1-2 were washed 10 times according to the AATCC 61 accelerated washing standard, and then the antibacterial properties of Examples 1, 4-7 and Comparative Examples 1-2 were tested according to the standard GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Oscillation method". The test strain was Staphylococcus aureus. The test results are shown in Table 2 below.

[0091] Table 1 Results of Antibacterial Performance Test

[0092]

[0093]

[0094] Table 2 Results of Antibacterial Performance Durability Test

[0095] Antibacterial rate / % Example 1 29 Example 4 36 Example 5 49 Example 6 39 Example 7 58

[0096] In conclusion, the following conclusions can be drawn:

[0097] 1. As can be seen from Example 1 and Comparative Examples 1-2 and Table 1, adding chitosan and tourmaline powder to the filter cloth can improve the antibacterial effect of the filter cloth. The reason may be that chitosan has antibacterial properties, and coating it on the surface of polyamide fibers can improve the antibacterial effect of the filter cloth. Tourmaline powder can emit far-infrared rays, which can penetrate the bacteria attached to the filter cloth, thereby heating the bacteria for a long time, inhibiting the growth activity of the bacteria, and helping to improve the antibacterial effect of chitosan.

[0098] 2. As can be seen from Examples 1 and 4 and Tables 1 and 2, HF treatment of polyamide fibers can improve the durability of the antibacterial effect of the filter cloth. The reason may be that the polyamide fibers undergo moderate corrosion under the etching effect of the HF atmosphere, which achieves the purpose of expanding and creating pores and forming a layered pore structure, thus roughening the surface of the polyamide fibers. After subsequent immersion in the impregnation solution and drying and weaving, the polyamide fibers in the filter cloth are squeezed against each other, causing tourmaline powder to be stuck in the concave pores on the surface of the polyamide fibers and increasing the friction between the tourmaline powder and the surface of the polyamide fibers. This reduces the occurrence of tourmaline powder falling off the surface of the polyamide fibers under the impact of the flowing liquid during use, thereby improving the durability of the antibacterial effect of the filter cloth.

[0099] 3. Combining Examples 1, 4-5, and 12 with Tables 1 and 2, it can be seen that adding wool fibers to the filter cloth and treating the polyamide fibers with HF can improve the durability of the filter cloth's antibacterial effect. The reason may be that wool fibers have felting properties. Adding wool fibers to the filter cloth can gradually increase the density of the filter cloth during repeated use, making the contact between tourmaline powder and polyamide fibers closer and larger, increasing the frictional resistance between tourmaline powder and polyamide fibers, and at the same time, making it easier to press the tourmaline powder into the pores on the surface of the polyamide fibers, thereby reducing the loss of tourmaline powder and further improving the antibacterial effect of the filter cloth.

[0100] 4. Based on Examples 1, 4, 6, and 13 and Tables 1 and 2, it can be seen that treating polyamide fibers with purple cabbage extract can improve the antibacterial effect of the filter cloth. The reason may be that purple cabbage extract contains a large amount of anthocyanins, and the cell wall components of microorganisms contain lipopolysaccharides. Anthocyanins can destroy the structure of lipopolysaccharides, causing the cell wall of microorganisms to permeate, thereby destroying the microbial cell structure, inhibiting bacterial reproduction, and improving the antibacterial effect of the filter cloth.

[0101] 5. Combining Examples 1, 4, 6-7, 13-14 with Tables 1 and 2, it can be seen that treating polyamide fibers with both purple cabbage extract and sodium alginate aqueous solution can improve the durability of the antibacterial effect of the filter cloth. The reason may be that the sodium alginate aqueous solution locks the purple cabbage extract onto the polyamide fibers, improving the adhesion and shaping effect of the purple cabbage extract on the polyamide fibers, and delaying the loss of purple cabbage extract during the use of the filter cloth.

[0102] 6. Combining Examples 1 and 7-8 with Tables 1 and 2, it can be seen that the static treatment after spraying sodium alginate aqueous solution onto the surface of polyamide fibers can improve the antibacterial effect of the filter cloth. The reason may be that it promotes the penetration of sodium alginate aqueous solution into the polyamide fibers, thereby locking the purple cabbage extract inside the polyamide fibers, while washing away excess sodium alginate aqueous solution on the surface of the polyamide fibers, so as to expose the surface of the polyamide fibers and make the surface of the polyamide fibers come into contact with the tourmaline powder.

[0103] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing an antibacterial filter cloth, characterized by, Includes the following steps: S1. Mix 10-13 parts by weight of tourmaline powder and 5-8 parts by weight of chitosan and add them to 50-60 parts by weight of acetic acid aqueous solution. Stir and mix for 15-20 minutes to obtain impregnation solution. S2. Place polyamide fibers on the sieve plate above the reaction tube in the hydrothermal reactor. Add 1-2 wt% HF solution below the sieve plate. Seal the hydrothermal reactor and transfer it to an oven. Perform a hydrothermal reaction at 90-100℃ for 1-2 hours. Then immerse the polyamide fibers in the impregnation solution. After removing them, dry them at 30-40℃. Next, twist the polyamide fibers and wool fibers in a spiral to obtain a blended yarn. Then arrange the warp and weft of the blended yarn and weave it into a mesh to obtain a filter cloth.

2. The method for preparing the antibacterial filter cloth according to claim 1, characterized in that: In step S2, after a hydrothermal reaction of 1-2 hours, the polyamide fiber is immersed in purple cabbage extract for 20-30 minutes, then dried at 60-70°C. The polyamide fiber is then immersed in the impregnation solution and then dried at 30-40°C.

3. The method of claim 2, wherein the method further comprises: The method for preparing the purple cabbage extract is as follows: crush the purple cabbage, then add 70-90 (v / v)% ethanol solution, stir and mix evenly, the weight ratio of purple cabbage to ethanol solution is 1:(6-8), heat the resulting product at 50-70℃ for 2-4 hours, let it stand to separate into layers, take the supernatant to obtain the purple cabbage extract.

4. The method of claim 2, wherein the method further comprises: In step S2, the polyamide fiber is immersed in purple cabbage extract for 20-30 minutes, then dried at 60-70°C. Next, sodium alginate aqueous solution is sprayed onto the surface of the polyamide fiber, and then dried at 60-70°C. Then, the polyamide fiber is immersed in the impregnation solution, and then dried at 30-40°C.

5. The method of claim 4, wherein: In step S2, after spraying sodium alginate aqueous solution onto the surface of polyamide fiber, it is left to stand for 20-30 minutes, rinsed with deionized water, and then dried at 60-70℃.

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