Antibacterial superfine fiber cleaning cloth and preparation method thereof

Abstract

The invention discloses an antibacterial superfine fiber cleaning cloth and a preparation method thereof, and relates to the technical field of superfine fiber cleaning cloth, in particular to the antibacterial superfine fiber cleaning cloth and the preparation method thereof, and the preparation method comprises the following steps: firstly, embedding soluble silver salt into fibers through melt blending spinning; and after being woven, gray fabric is treated by a bio-based reducing agent solution, so that silver ions are reduced into nano-silver in situ, and the antibacterial strong-cleaning layer is prepared. Secondly, preparing a high-fluffiness superfine fiber non-woven fabric as a high-water-absorption layer through a melt-spray spunlace process; then, the two antibacterial strong-cleaning layers and the high-water-absorption layer are overlapped, and the three layers of fibers are interspersed and entangled through vertical impact of a high-pressure water needle, so that a stable three-dimensional network mechanical combination structure is formed. And finally, carrying out alkali deweighting splitting, neutralization washing, soft finishing and hot air setting on the composite gray fabric to obtain a final product. According to the process, the built-in antibacterial function and the firm compounding between layers are realized, and the product has lasting antibacterial performance, efficient cleaning performance and high water absorption performance.

Description

Technical Field

[0001] This invention relates to the field of microfiber cleaning cloth technology, specifically to an antibacterial microfiber cleaning cloth and its preparation method. Background Technology

[0002] Microfiber cleaning cloths, also known as non-shedding fiber cleaning cloths, dust-free mercerized towels, or dust-free towels, are cleaning textiles made from microfiber. They are mainly made of nylon and polyester composite fibers and have super absorbency, cleaning power, and reusability. Their fiber structure achieves efficient cleaning through multiple scraping effects, wide contact area effects, and internal peeling effects. They are suitable for CLASS 10-100 cleanrooms, biomedical sterile workshops, semiconductor, electronic, photovoltaic industries, and optical device manufacturing.

[0003] Traditional microfiber cleaning cloths only provide antibacterial protection on the surface of the fibers, which is prone to washing off and not long-lasting. In particular, for functional multi-layer composite cleaning cloths, the core absorbent layer becomes a "hygiene dead zone" because it is not effectively covered by antibacterial ingredients. This not only makes it easy for microorganisms to grow and produce odors, but also poses a risk of secondary pollution. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an antibacterial microfiber cleaning cloth and its preparation method, solving the problems mentioned in the background art where traditional microfiber cleaning cloths only achieve antibacterial function on the surface of the fibers, resulting in easy washing off and short-lasting effects. Especially for functional multi-layer composite cleaning cloths, the core absorbent layer becomes a "hygiene dead zone" because it is not effectively covered by antibacterial components, making it prone to microbial growth and odor, and posing a risk of secondary pollution.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an antibacterial microfiber cleaning cloth, comprising a first strong cleaning layer, an absorbent layer, and a second strong cleaning layer, characterized in that: the first strong cleaning layer is the upper layer of the microfiber cleaning cloth, made of microfiber material containing nano-silver; the absorbent layer is the middle layer of the microfiber cleaning cloth, which is a microfiber nonwoven fabric prepared by hydroentangling; and the second strong cleaning layer is the lower layer of the microfiber cleaning cloth, made of microfiber material containing nano-silver.

[0006] A preferred method for preparing an antibacterial microfiber cleaning cloth according to the present invention includes the following steps:

[0007] S1. Soluble silver salts and polymer chips are melt-blended and granulated using a twin-screw extruder to produce silver-containing masterbatch. This masterbatch is then mixed with pure polymer chips and melt-spun to obtain fibers containing silver ions. The fibers are then woven into a high-cleanliness fabric using a weaving machine.

[0008] S2. The silver ion-containing strong cleaning layer fabric obtained above is immersed in a specific bio-based reducing agent solution and reacted at a certain temperature. The reducing agent reduces the silver ions that have penetrated into the fiber to atomic-state nano-silver particles in situ.

[0009] S3. After the reaction is complete, take out the strong cleaning layer fabric, wash it thoroughly with deionized water to remove residual ions and reagents on the surface, and then dry and shape it to obtain the final product.

[0010] S4. The ultrafine PET chips are fed into the screw extruder, heated to a molten state, and conveyed to the spinneret of the meltblown die to be extruded into fiber filaments. The high-speed, high-temperature hot air on both sides of the die instantly stretches the extruded polymer fiber filaments, making them thinner and then cooling and solidifying them into ultrafine and intertwined continuous fibers. These ultrafine fibers are evenly distributed on the continuously moving web forming curtain in a random manner under the blowing of the high-speed airflow, forming a fluffy fiber web with a certain thickness.

[0011] S5. The fluffy fiber web is passed through a pair of rollers or a low-pressure hydroentangling head to fully wet it. The pre-wetted fiber web then enters the hydroentangling zone, where high-pressure water jets penetrate vertically and impact the supporting screen below. Under the impact of the water jets, the fibers shift, tumble, interweave, and become tightly entangled. Because it is ultrafine fiber, its high flexibility allows it to form countless tiny, intricate three-dimensional porous structures under hydroentangling.

[0012] S6. The hydroentangled nonwoven fabric contains a large amount of moisture. It is first passed through one or more pairs of vacuum suction rollers to effectively remove most of the free moisture. Then, it enters a hot air circulating oven for drying and shaping at a temperature of 110-130°C, finally obtaining a finished super absorbent nonwoven fabric with a moisture content of less than 1%.

[0013] S7. Place the two prepared antibacterial and highly absorbent layers of fabric on the upper and lower sides of the middle super absorbent layer, respectively. After precise overlapping, feed them into the hydroentangling laminating machine through a conveyor screen. High-pressure water jets from above and below the machine vertically penetrate the entire three-layer structure from both sides. Under the impact of the water jets, the fibers on the surface of each layer are washed out and intertwine with each other, as if the three layers are "stitched" together with "water needle and thread". After lamination, a composite fabric with a unified structure and no layers is formed.

[0014] S8. The composite fabric is placed in an 8% sodium hydroxide solution and treated at 95°C for 45 minutes to open the microfiber. After opening, the fabric is neutralized and washed. Finally, the fabric is immersed in a hydrophilic silicone softener working solution at 50°C for 15 minutes to improve the hand feel. Then, it is dried and set at 130°C using a tenter frame to obtain stable dimensions and the final hand feel.

[0015] In a preferred embodiment of the preparation method of the antibacterial microfiber cleaning cloth of the present invention, the soluble silver salt and polymer chips in S1 are, by weight, 1 to 5 parts of soluble silver salt, 95 to 99 parts of polymer chips, 5 to 25 parts of silver masterbatch, and 75 to 95 parts of pure polymer chips.

[0016] In a preferred method for preparing an antibacterial microfiber cleaning cloth according to the present invention, the bio-based reducing agent in S2 is tannic acid with a concentration of 0.3% to 0.8%, and the reaction is carried out at a temperature of 55°C to 65°C.

[0017] In a preferred method for preparing an antibacterial microfiber cleaning cloth according to the present invention, the washing step in S3 involves first soaking and washing the cloth in a dilute nitric acid solution at a temperature of 40-50°C and a concentration of 0.05 mol / L for 10 minutes, followed by rinsing twice with deionized water at 60-70°C for 10 minutes each time, using the higher temperature hot water to accelerate the diffusion and removal of impurity molecules, and finally rinsing with room temperature deionized water at 25°C until the conductivity of the outflowing water is <10 μS / cm and the pH value is neutral, ensuring that there are no ion residues.

[0018] In a preferred embodiment of the method for preparing an antibacterial microfiber cleaning cloth according to the present invention, the diameter of the polymer fiber filaments prepared in step S4 is 0.1 to 0.5 denier.

[0019] In a preferred embodiment of the preparation method of the antibacterial microfiber cleaning cloth of the present invention, the water jet pressure in step S5 adopts a gradient increasing mode. The first pressure is set to 60-80 bar, mainly for initial entanglement; the subsequent hydroentanglement head pressure gradually increases to 100-120 bar, or even up to 150 bar, for deep entanglement and reinforcement. Furthermore, the water spray plate at the bottom of the hydroentanglement head is densely covered with extremely fine pores with a diameter of 0.1-0.12 mm. High-pressure water flow passes through these micropores to form extremely high-energy "water jets".

[0020] In a preferred method for preparing an antibacterial microfiber cleaning cloth according to the present invention, the drying and shaping process parameters in S6 are as follows: hot air temperature controlled between 110℃ and 130℃, hot air velocity between 1.5m / s and 2.5m / s, and drying time lasting from 90 seconds to 180 seconds.

[0021] In a preferred method for preparing an antibacterial microfiber cleaning cloth according to the present invention, the neutralization and washing step in S6 involves neutralizing the cloth with a 1% dilute acetic acid solution at 50°C for 10 minutes to terminate the alkaline reaction, followed by thorough washing with warm water until neutral.

[0022] This invention provides an antibacterial microfiber cleaning cloth and its preparation method, which has the following beneficial effects:

[0023] 1. This antibacterial microfiber cleaning cloth utilizes advanced material modification technology to integrate nano-silver antibacterial components into the microfibers that form the strong cleaning layer during the fiber preparation stage. Specifically, it employs a combination of melt blending and in-situ reduction to uniformly and stably immobilize nano-silver particles within the polymer matrix. This fundamentally endows the strong cleaning layer fabric with durable, efficient, and safe intrinsic antibacterial properties, rather than relying on easily detachable and poorly washable post-surface treatments.

[0024] 2. The preparation method of this antibacterial microfiber cleaning cloth employs a high-pressure hydroentangling composite process. This process utilizes a three-layer structure formed by multiple high-pressure water jets vertically impacting and stacking the microfibers on the surfaces of the upper and lower antibacterial and highly absorbent layers, allowing the fibers of the middle highly absorbent layer to be fully washed, interwoven, and entangled, forming a stable three-dimensional network mechanical bond. This achieves an integrated composite structure. This physical entanglement structure is crucial, as it ensures that the middle absorbent layer, which originally lacks antibacterial function, is physically and tightly covered and isolated by the two long-lasting antibacterial and highly absorbent layers. This design fundamentally prevents liquids and contaminants from lingering in the middle layer and creating "hygiene dead zones," because any microorganisms attempting to contact the middle layer must first penetrate the already highly effective antibacterial surface layer, thus being inhibited at the source and ensuring the overall hygiene safety and long-lasting antibacterial properties of the product. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the main structure of the present invention;

[0026] Figure 2 This is a comparison table of test results for the four composite methods of the present invention.

[0027] In the diagram: 1. First strong cleaning layer (1); 2. Absorbent layer (2); 3. Second strong cleaning layer (3). Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] Example 1

[0032] Please see Figure 1 and Figure 2 An antibacterial microfiber cleaning cloth and its preparation method are disclosed. The cloth comprises a first strong cleaning layer 1, an absorbent layer 2, and a second strong cleaning layer 3. The first strong cleaning layer 1 is the upper layer of the microfiber cleaning cloth and is made of microfiber material containing nano-silver. The absorbent layer 2 is the middle layer of the microfiber cleaning cloth and is a microfiber nonwoven fabric prepared by hydroentangling. The second strong cleaning layer 3 is the lower layer of the microfiber cleaning cloth and is made of microfiber material containing nano-silver.

[0033] In this implementation plan, advanced material modification technology is used to integrate nano-silver antibacterial components into the ultrafine fibers constituting the strong cleaning layer during the fiber preparation stage. Specifically, a combination of melt blending and in-situ reduction is employed to uniformly and stably immobilize nano-silver particles within the polymer matrix, thereby fundamentally endowing the strong cleaning layer fabric with durable, efficient, and safe intrinsic antibacterial properties, rather than relying on easily detachable and poorly washable post-surface treatments.

[0034] Furthermore:

[0035] In an optional embodiment, the following steps are included:

[0036] S1. Soluble silver salts and polymer chips are melt-blended and granulated using a twin-screw extruder to produce silver-containing masterbatch. This masterbatch is then mixed with pure polymer chips and melt-spun to obtain fibers containing silver ions. The fibers are then woven into a high-cleanliness fabric using a weaving machine.

[0037] S2. The silver ion-containing strong cleaning layer fabric obtained above is immersed in a specific bio-based reducing agent solution and reacted at a certain temperature. The reducing agent reduces the silver ions that have penetrated into the fiber to atomic-state nano-silver particles in situ.

[0038] S3. After the reaction is complete, take out the strong cleaning layer fabric, wash it thoroughly with deionized water to remove residual ions and reagents on the surface, and then dry and shape it to obtain the final product.

[0039] S4. The ultrafine PET chips are fed into the screw extruder, heated to a molten state, and conveyed to the spinneret of the meltblown die to be extruded into fiber filaments. The high-speed, high-temperature hot air on both sides of the die instantly stretches the extruded polymer fiber filaments, making them thinner and then cooling and solidifying them into ultrafine and intertwined continuous fibers. These ultrafine fibers are evenly distributed on the continuously moving web forming curtain in a random manner under the blowing of the high-speed airflow, forming a fluffy fiber web with a certain thickness.

[0040] S5. The fluffy fiber web is passed through a pair of rollers or a low-pressure hydroentangling head to fully wet it. The pre-wetted fiber web then enters the hydroentangling zone, where high-pressure water jets penetrate vertically and impact the supporting screen below. Under the impact of the water jets, the fibers shift, tumble, interweave, and become tightly entangled. Because it is ultrafine fiber, its high flexibility allows it to form countless tiny, intricate three-dimensional porous structures under hydroentangling.

[0041] S6. The hydroentangled nonwoven fabric contains a large amount of moisture. It is first passed through one or more pairs of vacuum suction rollers to effectively remove most of the free moisture. Then, it enters a hot air circulating oven for drying and shaping at a temperature of 110-130°C, finally obtaining a finished super absorbent nonwoven fabric with a moisture content of less than 1%.

[0042] S7. Place the two prepared antibacterial and highly absorbent layers of fabric on the upper and lower sides of the middle super absorbent layer, respectively. After precise overlapping, feed them into the hydroentangling laminating machine through a conveyor screen. High-pressure water jets from above and below the machine vertically penetrate the entire three-layer structure from both sides. Under the impact of the water jets, the fibers on the surface of each layer are washed out and intertwine with each other, as if the three layers are "stitched" together with "water needle and thread". After lamination, a composite fabric with a unified structure and no layers is formed.

[0043] S8. The composite fabric is placed in an 8% sodium hydroxide solution and treated at 95°C for 45 minutes to open the microfiber. After opening, the fabric is neutralized and washed. Finally, the fabric is immersed in a hydrophilic silicone softener working solution at 50°C for 15 minutes to improve the hand feel. Then, it is dried and set at 130°C using a tenter frame to obtain stable dimensions and the final hand feel.

[0044] In this implementation plan, a high-pressure hydroentanglement composite process is employed. This process utilizes a three-layer structure formed by the vertical impact of multiple high-pressure water jets. The ultrafine fibers on the surfaces of the upper and lower antibacterial and highly absorbent layers are thoroughly washed, interwoven, and entangled with the fibers of the middle highly absorbent layer, forming a stable three-dimensional network mechanical bond. This achieves an integrated composite structure. This physical entanglement structure is crucial, as it ensures that the middle absorbent layer, which originally lacks antibacterial function, is physically and tightly covered and isolated by the two long-lasting antibacterial and highly absorbent layers. This design fundamentally prevents liquids and contaminants from lingering in the middle layer and creating "hygiene dead zones." Any microorganisms attempting to contact the middle layer must first penetrate the already highly effective antibacterial surface layer, thus being inhibited at the source and ensuring the overall hygiene safety and long-lasting antibacterial properties of the product.

[0045] Furthermore:

[0046] In an optional embodiment, the soluble silver salt and polymer chips in S1 are in the following weight parts: 1 to 5 parts of soluble silver salt, 95 to 99 parts of polymer chips, 5 to 25 parts of silver-containing masterbatch, and 75 to 95 parts of pure polymer chips.

[0047] In this implementation scheme: High concentration and uniform dispersion of nano-silver are achieved during the masterbatch preparation stage (1-5 parts silver salt, 95-99 parts polymer). Then, during the spinning stage, the effective content of nano-silver in the final fiber is precisely controlled by flexibly adjusting the ratio of masterbatch to pure chips from 5:95 to 25:75. This method perfectly balances three core requirements: first, it ensures a strong and long-lasting antibacterial effect; second, it avoids the problems of poor fiber spinnability and reduced strength caused by excessive silver salt; and third, it provides a broad process window for industrial production, allowing antibacterial performance to be precisely customized according to needs, while also considering cost-effectiveness.

[0048] Furthermore:

[0049] In an optional embodiment, the bio-based reducing agent in S2 is tannic acid with a concentration of 0.3% to 0.8%, and the reaction is carried out at a temperature of 55°C to 65°C.

[0050] In this implementation scheme, the bio-based reducing agent tannic acid, at a concentration of 0.3%–0.8% and a reaction temperature of 55°C–65°C, constitutes a highly efficient and controllable process window. These conditions ensure the complete and uniform reduction of silver ions into highly active silver nanoparticles, while also effectively preventing the aggregation of silver nanoparticles through the end-capping effect of tannic acid itself. The mild reaction temperature guarantees high efficiency while avoiding damage to the ultrafine fiber structure, thus achieving a long-lasting and stable integrated antibacterial function under the premise of green environmental protection.

[0051] Furthermore:

[0052] In an optional embodiment, the washing step in S3 is as follows: first, soak and wash with a dilute nitric acid solution at a temperature of 40-50°C and a concentration of 0.05 mol / L for 10 minutes; then rinse twice with deionized water at 60-70°C for 10 minutes each time, using the higher temperature hot water to accelerate the diffusion and removal of impurity molecules; finally, rinse with room temperature deionized water at 25°C until the conductivity of the outflowing water is <10 μS / cm and the pH value is neutral, ensuring that there are no ion residues.

[0053] In this implementation plan, a combination of precisely controlled acidic washing, hot water washing, and a final wash at room temperature, with conductivity <10μS / cm and neutral pH as quantifiable endpoint indicators, can efficiently and thoroughly remove residual reaction byproducts and ionic impurities from the fibers. This process not only ensures the purity and stability of the bond between nano-silver and the fiber, completely eliminating potential skin irritation or reduced antibacterial efficacy due to residues, but also provides a strict and verifiable unified standard for product quality.

[0054] Furthermore:

[0055] In an optional embodiment, the polymer fiber filaments prepared in S4 have a diameter of 0.1 to 0.5 denier.

[0056] In this implementation scheme, ultrafine fibers of 0.1 to 0.5 denier are used. Their extremely high specific surface area generates a powerful capillary effect, giving the cleaning cloth excellent dust-locking, oil-absorbing, and rapid water-absorbing capabilities. At the same time, the ultrafine fibers ensure a soft texture, allowing the cloth to gently care for the surface being cleaned while providing efficient cleaning. This diameter range is the physical basis for achieving its powerful cleaning function and delicate feel.

[0057] Furthermore:

[0058] In an optional embodiment, the water needle pressure in S5 adopts a gradient increasing mode. The first pressure is set to 60-80 bar, mainly for initial entanglement; the subsequent water jet head pressure gradually increases to 100-120 bar, or even up to 150 bar, for deep entanglement and reinforcement. Furthermore, the water spray plate at the bottom of the water jet head is densely covered with extremely fine pores with a diameter of 0.1-0.12 mm. The high-pressure water flow passes through these micropores to form extremely high-energy "water needles".

[0059] In this implementation scheme, a water jet gradient pressurization mode (60-80 bar to 150 bar) combined with an ultra-fine pore size design of 0.1-0.12 mm constitutes a precise and controllable composite process. This design enables uniform entanglement from shallow to deep layers, avoiding structural damage or interlayer displacement that may be caused by one-time high pressure. Ultimately, without the need for chemical adhesives, it endows the three-layer composite material with extremely high interlayer bonding strength, excellent durability, and fully preserves the permeability and soft feel of each functional layer.

[0060] Furthermore:

[0061] In an optional embodiment, the drying and shaping process parameters in S6 are: hot air temperature controlled between 110°C and 130°C, hot air velocity between 1.5 m / s and 2.5 m / s, and drying time lasting between 90 and 180 seconds.

[0062] In this implementation scheme, by setting a combination of hot air temperature of 110-130℃, air velocity of 1.5-2.5m / s, and drying time of 90-180 seconds, efficient and gentle dehydration and heat setting can be achieved. This parameter window ensures that moisture is removed quickly, evenly, and thoroughly, preventing residual moisture from causing microbial growth; it also appropriately relaxes the internal stress of the fibers, giving the product stable dimensions and a lasting fluffy feel, while avoiding heat damage to the fibers and the built-in nano-silver antibacterial ingredients caused by excessively high temperatures.

[0063] Furthermore:

[0064] In an optional embodiment, the neutralization and washing step in S6 involves neutralizing the fabric with a 1% dilute acetic acid solution at 50°C for 10 minutes to terminate the alkaline reaction, followed by thorough washing with warm water until neutral.

[0065] In this implementation plan, a neutralization treatment with 1% dilute acetic acid at 50°C for 10 minutes is used. This can quickly, gently, and thoroughly terminate the residual alkali reaction after alkali reduction and fiber opening, precisely control the degree of hydrolysis, and thus effectively protect the strength and integrity of the microfiber. This process ensures the stability of the product's softness and physical properties, and avoids fabric damage or chemical and biological safety issues caused by alkali residue, providing a key guarantee for the quality of the final product.

[0066] Comparative Example 1

[0067] Hot melt adhesive powder is evenly sprayed onto the upper and lower surfaces of the middle absorbent layer using a powder spraying device, then stacked with the upper and lower strong cleaning layers, and the adhesive powder is melted in a high-temperature drying oven before being cooled and bonded by pressure rollers.

[0068] Comparative Example 2

[0069] One side of the middle absorbent layer is subjected to an instantaneous high-temperature flame to melt its surface, and then immediately bonded to the lower strong cleaning layer by a pressure roller. The other side is treated in the same way.

[0070] Comparative Example 3

[0071] A layer of low-melting-point double-sided adhesive film is added between the middle absorbent layer and the upper and lower strong cleaning layers, and the film is melted and bonded by hot pressing.

[0072] Based on the comparative experimental data above, it can be clearly concluded that the spunlace composite method significantly surpasses traditional composite processes in key performance indicators such as initial strength and wash durability of the composite structure, integrity of the core water absorption and cleaning function, environmental friendliness of the production process, and hygiene and safety in inhibiting microbial cross-contamination. This process achieves structural integration through physical entanglement, fundamentally solving the industry challenges of durability and hygiene and safety in multi-layer functional textiles. It is the most ideal and irreplaceable core technology solution for preparing high-performance, long-life antibacterial cleaning cloths.

[0073] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A microfiber cleaning cloth with antibacterial properties, characterized in that, The first strong cleaning layer (1), the absorbent layer (2), and the second strong cleaning layer (3) are characterized in that: the first strong cleaning layer (1) is the upper layer of the microfiber cleaning cloth, which is made of microfiber material containing nano-silver; the absorbent layer (2) is the middle layer of the microfiber cleaning cloth, which is microfiber nonwoven fabric prepared by hydroentangling; and the second strong cleaning layer (3) is the lower layer of the microfiber cleaning cloth, which is made of microfiber material containing nano-silver.

2. The method for preparing an antibacterial microfiber cleaning cloth according to claim 1, characterized in that, Includes the following steps: S1. Soluble silver salts and polymer chips are melt-blended and granulated using a twin-screw extruder to produce silver-containing masterbatch. This masterbatch is then mixed with pure polymer chips and melt-spun to obtain fibers containing silver ions. The fibers are then woven into a high-cleanliness fabric using a weaving machine. S2. The silver ion-containing strong cleaning layer fabric obtained above is immersed in a specific bio-based reducing agent solution and reacted at a certain temperature. The reducing agent reduces the silver ions that have penetrated into the fiber to atomic-state nano-silver particles in situ. S3. After the reaction is complete, take out the strong cleaning layer fabric, wash it thoroughly with deionized water to remove residual ions and reagents on the surface, and then dry and shape it to obtain the final product. S4. The ultrafine PET chips are fed into the screw extruder, heated to a molten state, and conveyed to the spinneret of the meltblown die to be extruded into fiber filaments. The high-speed, high-temperature hot air on both sides of the die instantly stretches the extruded polymer fiber filaments, making them thinner and then cooling and solidifying them into ultrafine and intertwined continuous fibers. These ultrafine fibers are evenly distributed on the continuously moving web forming curtain in a random manner under the blowing of the high-speed airflow, forming a fluffy fiber web with a certain thickness. S5. The fluffy fiber web is passed through a pair of rollers or a low-pressure hydroentangling head to fully wet it. The pre-wetted fiber web then enters the hydroentangling zone, where high-pressure water jets penetrate vertically and impact the supporting screen below. Under the impact of the water jets, the fibers shift, tumble, interweave, and become tightly entangled. Because it is ultrafine fiber, its high flexibility allows it to form countless tiny, intricate three-dimensional porous structures under hydroentangling. S6. The hydroentangled nonwoven fabric contains a large amount of moisture. It is first passed through one or more pairs of vacuum suction rollers to effectively remove most of the free moisture. Then, it enters a hot air circulating oven for drying and shaping at a temperature of 110-130°C, finally obtaining a finished super absorbent nonwoven fabric with a moisture content of less than 1%. S7. Place the two prepared antibacterial and highly absorbent layers of fabric on the upper and lower sides of the middle super absorbent layer, respectively. After precise overlapping, feed them into the hydroentangling laminating machine through a conveyor screen. High-pressure water jets from above and below the machine vertically penetrate the entire three-layer structure from both sides. Under the impact of the water jets, the fibers on the surface of each layer are washed out and intertwine with each other, as if the three layers are "stitched" together with "water needle and thread". After lamination, a composite fabric with a unified structure and no layers is formed. S8. The composite fabric is placed in an 8% sodium hydroxide solution and treated at 95°C for 45 minutes to open the microfiber. After opening, the fabric is neutralized and washed. Finally, the fabric is immersed in a hydrophilic silicone softener working solution at 50°C for 15 minutes to improve the hand feel. Then, it is dried and set at 130°C using a tenter frame to obtain stable dimensions and the final hand feel.

3. The method for preparing an antibacterial microfiber cleaning cloth according to claim 2, characterized in that, The soluble silver salt and polymer chips in S1 are in the following proportions by weight: 1-5 parts soluble silver salt, 95-99 parts polymer chips, 5-25 parts silver masterbatch, and 75-95 parts pure polymer chips.

4. The method for preparing an antibacterial microfiber cleaning cloth according to claim 2, characterized in that, The bio-based reducing agent in S2 is tannic acid, with a concentration of 0.3% to 0.8%, and the reaction is carried out at a temperature of 55°C to 65°C.

5. The method for preparing an antibacterial microfiber cleaning cloth according to claim 2, characterized in that, The washing step in S3 is as follows: First, soak and wash with a dilute nitric acid solution at a temperature of 40-50℃ and a concentration of 0.05mol / L for 10 minutes. Then, rinse twice with deionized water at 60-70℃ for 10 minutes each time. The higher temperature hot water accelerates the diffusion and removal of impurity molecules. Finally, rinse with room temperature deionized water at 25℃ until the conductivity of the outflowing water is <10μS / cm and the pH value is neutral, ensuring that there are no ion residues.

6. The method for preparing an antibacterial microfiber cleaning cloth according to claim 2, characterized in that, The polymer fiber filaments prepared in S4 have a diameter of 0.1 to 0.5 denier.

7. The method for preparing an antibacterial microfiber cleaning cloth according to claim 2, characterized in that, The water jet pressure in S5 adopts a gradient increasing mode. The first pressure is set to 60-80 bar, mainly for initial entanglement. The pressure of subsequent water jet heads gradually increases to 100-120 bar, or even up to 150 bar, for deep entanglement and reinforcement. The water spray plate at the bottom of the water jet head is densely covered with extremely fine holes with a diameter of 0.1-0.12 mm. The high-pressure water flow passes through these micropores to form a water jet with extremely high energy.

8. The method for preparing an antibacterial microfiber cleaning cloth according to claim 2, characterized in that, The drying and shaping process parameters in S6 are as follows: hot air temperature controlled between 110°C and 130°C, hot air velocity between 1.5m / s and 2.5m / s, and drying time lasting from 90 seconds to 180 seconds.

9. The method for preparing an antibacterial microfiber cleaning cloth according to claim 2, characterized in that, The neutralization and washing step in S6 involves neutralizing the fabric with a 1% dilute acetic acid solution at 50°C for 10 minutes to terminate the alkaline reaction, followed by thorough washing with warm water until neutral.

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