Moisture-absorbing breathable medical bandage and preparation method thereof

Abstract

The invention discloses a moisture-absorbing breathable medical bandage and a preparation method thereof, and relates to the technical field of medical treatment, the bandage comprises a bandage inner layer, a bandage middle layer and a bandage outer layer which are compounded in sequence, through the hydrophilic and hydrophobic design of a Janus structure of the bandage middle layer, two opposite functions are creatively integrated into a whole, and the moisture-absorbing breathable medical bandage has the advantages of being simple in structure and convenient to use. The strong capillary force generated by the hydrophilic-hydrophobic interface is utilized to actively and quickly pump water vapor generated by the wound surface from inside to outside, and evaporation is accelerated from the outer layer. By means of the intelligent one-way moisture guiding mechanism, it is ensured that the wound surface is always in the dry and comfortable'wet healing 'optimal environment, meanwhile, invasion of external liquid is completely eradicated, and the technical difficulty that a traditional bandage is either stuffy and sticky after absorbing moisture or is waterproof but not breathable is solved. According to the invention, a silver ion antibacterial agent which is easy to lose and has potential cytotoxicity is abandoned, and a body-integrated chitosan quaternary ammonium salt antibacterial system is adopted, so that cytotoxicity and anaphylaxis possibly brought by silver ions are avoided, and the use is safer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical technology, in particular to a moisture-absorbing and air-permeable medical bandage and a preparation method thereof. BACKGROUND

[0002] As a basic surgical dressing, medical bandages are widely used in clinical scenarios such as wound protection, fixing gauze, absorbing a small amount of exudate, and applying pressure. An ideal medical bandage needs to protect the wound while creating the best environment for wound healing. This requires it to have multiple coordinated and seemingly contradictory properties. First, it should effectively block external liquid penetration to prevent infection. Second, it needs excellent moisture management capability, that is, not only can it efficiently absorb water vapor emitted from the wound, but also can quickly export it outward to keep the wound dry and avoid excessive moisture or accumulation. In addition, good antibacterial ability is the key to preventing wound infection. At the same time, the bandage itself should be light, thin, and flexible, making it easy to be comfortably and stably wrapped around the body and easily peeled off when replaced to avoid secondary damage. However, the existing traditional bandages and improved products are difficult to fully meet the above requirements and have obvious technical shortcomings.

[0003] First, traditional cotton yarn bandages and viscose fiber bandages have certain moisture absorption, but their moisture absorption mechanism is "storage" rather than "guidance". After absorbing liquid, the material will form a saturated wet area, which is extremely easy to adhere to the wound granulation tissue, causing tearing of the wound when replaced, and its air permeability will also decrease sharply, forming a humid and closed environment around the wound, which in turn accelerates bacterial reproduction.

[0004] To improve water resistance, there are bandages on the market that have been finished with hydrophobic compounds. Although these products can block liquid to some extent, their hydrophobic coating often severely sacrifices the material's moisture permeability, causing the water vapor generated from the wound to be unable to be discharged in time, and also failing to handle a small amount of exudate.

[0005] In another technical path of pursuing moisture absorption, high moisture absorption materials (such as calcium alginate fibers, superabsorbent resins, etc.) are widely used. However, such materials generally swell and harden after absorbing a large amount of liquid, severely sacrificing the flexibility and air permeability of the bandage, and the gel-like exudate, if not promptly removed, will also cause the wound to be soaked. In addition, existing technical solutions are difficult to achieve intelligent differentiation and coordination in the two opposite directions of "blocking external liquid" and "exporting internal moisture outward".

[0006] Therefore, there is an urgent need in the art for a comprehensive solution that can break through the shackles of existing technology and develop a new type of medical bandage that combines "lightness, hydrophobicity (to prevent external liquid), high air permeability, intelligent moisture management (moisture absorption and moisture guidance), long-term antibacterial ability, excellent flexibility, and easy peelability". SUMMARY

[0007] To address the problems mentioned above in the background art, the inventors provide a moisture-wicking and breathable medical bandage and its preparation method.

[0008] A moisture-wicking and breathable medical bandage includes an inner bandage layer, a middle bandage layer, and an outer bandage layer that are sequentially laminated together. The inner layer of the bandage is a composite fiber layer prepared by electrospinning with parallel dual nozzles, including fibers formed by structural spinning solution and fibers formed by functional spinning solution. The functional spinning solution contains nonionic surfactant Pluronic F-127, polycaprolactone and chitosan quaternary ammonium salt. The middle layer of the bandage includes a fiber cloth and a through-hole circular micropore array disposed thereon, and the middle layer of the bandage has a hydrophilic-hydrophobic Janus structure, wherein the hydrophilic surface faces the inner layer of the bandage and the hydrophobic surface faces the outer layer of the bandage. The outer layer of the bandage is an elastic non-woven fabric made of pure cotton fibers and spandex filaments that are web-formed by airflow and bonded by hot air.

[0009] The structural spinning solution is a polycaprolactone solution in hexafluoroisopropanol with a concentration of 10-14% (w / v); the functional spinning solution is a solution of Pluronic F-127, polycaprolactone, and chitosan quaternary ammonium salt dissolved in a mixed solvent of hexafluoroisopropanol and deionized water with a total concentration of 9-12% (w / v).

[0010] The fiber cloth is made by electrospinning polylactic acid and polycaprolactone dissolved in a mixed solvent of dichloromethane and N,N-dimethylformamide, with a spinning solution concentration of 8-12% (w / v).

[0011] The through-hole circular micropore array has a pore size of 15-25μm and a pore spacing of 80-120μm, and is formed by ultraviolet laser engraving.

[0012] The hydrophobic surface of the bandage's intermediate layer is formed by vapor deposition of a fluorinated silane vapor on one side, wherein the fluorinated silane is heptadecafluorodecyltrimethoxysilane.

[0013] The mass ratio of pure cotton fiber to spandex filament in the outer layer of the bandage is 70-80:20-30. The spandex filament is 40D and has been treated with an emulsifier or blended with low-melting-point polyester fiber.

[0014] A method for preparing a moisture-wicking and breathable medical bandage, comprising the following steps: Step 1: Dissolve polycaprolactone in hexafluoroisopropanol to prepare a 10-14% (w / v) solution as the structural spinning solution. Dissolve the nonionic surfactant (Pluronic F-127), polycaprolactone, and chitosan quaternary ammonium salt in a mixed solvent composed of hexafluoroisopropanol and deionized water to prepare a 9-12% (w / v) solution as the functional spinning solution. The mass ratio of the nonionic surfactant (Pluronic F-127), polycaprolactone, and chitosan quaternary ammonium salt dissolved in hexafluoroisopropanol is 12:8:1, and the volume ratio of hexafluoroisopropanol to deionized water is 9:1. Step 2: Load the structural spinning solution and functional spinning solution from Step 1 into the injection pump of the parallel dual-nozzle electrospinning equipment. Set the propulsion flow rates of the structural spinning solution and functional spinning solution to 1.0 mL / h and 0.5 mL / h, respectively. Set the receiving distance to 18 cm and apply a voltage of 20 kV. Perform spinning in an environment with a temperature of 25 ± 2 ℃ and a humidity of 60 ± 5% to obtain the inner layer of the bandage. Step 3: Dissolve polylactic acid and polycaprolactone together in a mixed solvent of dichloromethane and N,N-dimethylformamide to prepare a spinning solution with a concentration of 8-12% (w / v). Propel the spinning solution at a flow rate of 1.2 mL / h, with a receiving distance of 15 cm, apply a voltage of 18 kV, and control the ambient humidity below 40%. Collect a fiber cloth of uniform thickness. The mass ratio of polylactic acid to polycaprolactone is 7:3, and the volume ratio of dichloromethane to N,N-dimethylformamide is 7:3. Step 4: The fiber cloth from Step 3 is flattened and fixed on the worktable of the UV laser engraving machine. Under the laser parameters of 15W laser power, 500mm / s scanning speed and 50kHz frequency, a through-hole circular micro-hole array with a pore size of 15-25μm and a pore spacing of 80-120μm is etched on the fiber cloth. The residual debris on the surface is cleaned with a clean and dry airflow of 0.2MPa to obtain the intermediate layer substrate of the bandage. Step 5: Using a masking fixture, expose only one side of the bandage interlayer substrate obtained in Step 4 to the treatment chamber. Introduce a gas mixture consisting of 1% by volume of heptadecafluorodecyltrimethoxysilane vapor and 99% by volume of nitrogen into the chamber, and treat at 120°C for 30 minutes. This process imparts superhydrophobicity to the exposed surface while maintaining hydrophilicity to the masked surface, thus constructing a hydrophilic-hydrophobic Janus structure as the bandage interlayer. Step 6: The pure cotton fiber and the spandex filament are evenly mixed and laid out using a high-speed airflow web forming machine. After that, they are bonded and reinforced under hot air at 125°C for 60 seconds to obtain the outer layer of the bandage. The mass ratio of pure cotton fiber to spandex filament is 70-80:20-30. Step 7: Stack the inner bandage layer obtained in Step 2, the middle bandage layer obtained in Step 5, and the outer bandage layer obtained in Step 6 in sequence. Using an 80-mesh anilox roller, transfer the water-based polyurethane adhesive with a solid content of 40% in an intermittent dot pattern between the middle and outer layers, and between the inner and middle layers. Control the amount of adhesive applied by weight to 12±1g / m². Feed the three layers into a flatbed hot press laminating machine and press them together for 20 seconds at a temperature of 60℃ and a pressure of 0.15MPa. Then, put the semi-finished product into a 60℃ circulating hot air drying tunnel and dry it for 3 minutes to completely cure the adhesive. Finally, cool it to room temperature with a cooling roller, roll it up, and cut it to the required size to obtain the moisture-absorbing and breathable medical bandage of the present invention.

[0015] In step two, the parallel dual-nozzle electrospinning equipment uses a 21G parallel composite nozzle to ensure that the structural spinning solution and the functional spinning solution are in parallel contact at the nozzle but do not mix.

[0016] In step six, the average length of the pure cotton fiber is 38mm, the micronaire value is 4.0-4.5, the fineness is 1.5-1.8, the spandex filament specification is 40D, and the surface is treated with a light emulsifier or blended with a small amount of low melting point polyester fiber.

[0017] The beneficial effects of this invention are: This invention creatively integrates two opposing functions into one through the Janus structure hydrophilic-hydrophobic design of the middle layer of the bandage. Utilizing the powerful capillary force generated by the hydrophilic-hydrophobic interface, it actively and rapidly "pumps" water vapor generated on the wound surface from the inside to the outside, and accelerates its evaporation from the outer layer. This intelligent one-way moisture-wicking mechanism ensures that the wound surface is always in an optimal environment for "moist healing" while preventing the intrusion of external liquids, thus solving the technical dilemma of traditional bandages that either become damp and sticky after absorbing moisture or are waterproof but not breathable. This invention abandons the easily lost and potentially cytotoxic silver ion antibacterial agents, and instead employs a "bulk-integrated" chitosan quaternary ammonium salt antibacterial system. Chitosan quaternary ammonium salt physically disrupts bacterial cell membranes through electrostatic interactions, providing broad-spectrum antibacterial activity without easily inducing drug resistance. More importantly, these antibacterial components are firmly anchored in the fiber bulk through blend spinning, avoiding the rapid loss of post-treatment antibacterial agents and achieving long-lasting antibacterial effects. Simultaneously, this system avoids the potential cytotoxicity and allergic reactions associated with silver ions, making it safer to use. This invention, through its ultra-thin fiber interlayer and highly elastic outer layer design, achieves an extremely thin and flexible bandage while ensuring excellent mechanical strength. This allows it to perfectly conform to various joints of the body, providing a secure bandage while allowing for free movement. Particularly noteworthy is the inclusion of a smart responsive polymer (Pluronic F-127) in the inner layer. This makes the bandage stable in a dry state, and upon contact with saline solution during dressing changes, it rapidly hydrates to form a lubricating layer, achieving an "on-demand" easy-peel function. This significantly reduces patient pain and the risk of secondary injury during dressing changes, demonstrating significant clinical advantages. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the moisture-absorbing and breathable medical bandage of the present invention; Figure 2 This is a schematic diagram of the middle layer of the bandage in this invention; Figure 3 This is a schematic diagram of the active moisture-wicking middle layer of the bandage in this invention; Figure 4 This is a microscopic electron microscope image of the moisture-absorbing and breathable medical bandage of this invention; Figure 5 This is a diagram illustrating the antibacterial effect of the moisture-wicking and breathable medical bandage in this invention. In the picture: 1. Moisture-wicking and breathable medical bandage; 11. Inner layer of bandage; 12. Middle layer of bandage; 121. Fiber cloth; 122. Through-type circular microporous array; 13. Outer layer of bandage. Detailed Implementation

[0019] To better illustrate the preparation process involved in this invention and its advantages over the prior art, further explanation will be provided with reference to the accompanying drawings.

[0020] A moisture-wicking and breathable medical bandage includes an inner bandage layer 11, a middle bandage layer 12, and an outer bandage layer 13, which are sequentially laminated together. The inner layer 11 of the bandage is a composite fiber layer prepared by electrospinning with parallel dual nozzles, including fibers formed by structural spinning solution and fibers formed by functional spinning solution. The functional spinning solution contains nonionic surfactant Pluronic F-127, polycaprolactone and chitosan quaternary ammonium salt. The middle layer 12 of the bandage includes a fiber cloth 121 and a through-hole circular micropore array 122 disposed thereon, and the middle layer 12 of the bandage has a hydrophilic-hydrophobic Janus structure, wherein the hydrophilic surface faces the inner layer 11 of the bandage and the hydrophobic surface faces the outer layer 13 of the bandage. The outer layer 13 of the bandage is an elastic nonwoven fabric made of pure cotton fibers and spandex filaments that are web-formed by airflow and bonded by hot air.

[0021] The structural spinning solution is a polycaprolactone solution in hexafluoroisopropanol with a concentration of 10-14% (w / v); the functional spinning solution is a solution of Pluronic F-127, polycaprolactone, and chitosan quaternary ammonium salt dissolved in a mixed solvent of hexafluoroisopropanol and deionized water with a total concentration of 9-12% (w / v).

[0022] The fiber cloth 121 is made by electrospinning polylactic acid and polycaprolactone dissolved in a mixed solvent of dichloromethane and N,N-dimethylformamide, with a spinning solution concentration of 8-12% (w / v).

[0023] The through-hole circular micropore array 122 has a pore diameter of 15-25μm and a pore spacing of 80-120μm, and is formed by ultraviolet laser engraving.

[0024] The hydrophobic surface of the bandage intermediate layer 12 is formed by vapor deposition of a fluorinated silane vapor with one side exposed to it. The fluorinated silane is heptadecafluorodecyltrimethoxysilane.

[0025] The outer layer 13 of the bandage has a mass ratio of pure cotton fiber to spandex filament of 70-80:20-30. The spandex filament is 40D and has been treated with an emulsifier or blended with low-melting-point polyester fiber.

[0026] A method for preparing a moisture-wicking and breathable medical bandage, comprising the following steps: Step 1: Dissolve polycaprolactone in hexafluoroisopropanol to prepare a 10-14% (w / v) solution as the structural spinning solution. Dissolve the nonionic surfactant (Pluronic F-127), polycaprolactone, and chitosan quaternary ammonium salt in a mixed solvent composed of hexafluoroisopropanol and deionized water to prepare a 9-12% (w / v) solution as the functional spinning solution. The mass ratio of the nonionic surfactant (Pluronic F-127), polycaprolactone, and chitosan quaternary ammonium salt dissolved in hexafluoroisopropanol is 12:8:1, and the volume ratio of hexafluoroisopropanol to deionized water is 9:1. Step 2: The structural spinning solution and functional spinning solution from Step 1 are loaded into the injection pump of the parallel dual-nozzle electrospinning equipment. The propulsion flow rates of the structural spinning solution and the functional spinning solution are set to 1.0 mL / h and 0.5 mL / h, respectively. The receiving distance is fixed at 18 cm. The applied voltage is 20 kV. Spinning is carried out in an environment with a temperature of 25±2℃ and a humidity of 60±5% to obtain the inner layer 11 of the bandage. Step 3: Dissolve polylactic acid and polycaprolactone together in a mixed solvent of dichloromethane and N,N-dimethylformamide to prepare a spinning solution with a concentration of 8-12% (w / v). Propel the spinning solution at a flow rate of 1.2 mL / h, with a receiving distance of 15 cm, apply a voltage of 18 kV, and control the ambient humidity below 40%. Collect a fiber cloth 121 with uniform thickness. The mass ratio of polylactic acid to polycaprolactone is 7:3, and the volume ratio of dichloromethane to N,N-dimethylformamide is 7:3. Step 4: Fix the fiber cloth 121 from Step 3 flat on the worktable of the UV laser engraving machine. Under the laser parameters of 15W laser power, 500mm / s scanning speed and 50kHz frequency, etch a through-hole circular micro-hole array 122 with a hole diameter of 15-25μm and a hole spacing of 80-120μm on the fiber cloth. Clean the residual debris on the surface with a clean and dry airflow of 0.2MPa to obtain the intermediate layer substrate of the bandage. Step 5: Using a masking fixture, only one side of the bandage interlayer substrate obtained in Step 4 is exposed to the treatment chamber. A gas mixture consisting of 1% by volume of heptadecafluorodecyltrimethoxysilane vapor and 99% by volume of nitrogen is introduced into the chamber, and the mixture is treated at 120°C for 30 minutes. This makes the exposed surface superhydrophobic while the masked surface remains hydrophilic, thus constructing a hydrophilic-hydrophobic Janus structure as the bandage interlayer 12. Step 6: The pure cotton fiber and the spandex filament are evenly mixed and laid out using a high-speed airflow web forming machine. After the web is laid out, it is bonded and reinforced under hot air at 125℃ for 60 seconds to obtain the outer layer 13 of the bandage. The mass ratio of pure cotton fiber to spandex filament is 70-80:20-30. Step 7: Stack the inner bandage layer 11 obtained in Step 2, the middle bandage layer 12 obtained in Step 5, and the outer bandage layer 13 obtained in Step 6 in sequence. Using an 80-mesh anilox roller, transfer the water-based polyurethane adhesive with a solid content of 40% in an intermittent dot pattern between the middle and outer layers, and between the inner and middle layers. Control the amount of adhesive applied by weight to 12±1g / m². Feed the three layers into a flatbed hot press laminating machine and press them together for 20 seconds at a temperature of 60℃ and a pressure of 0.15MPa. Then, put the semi-finished product into a 60℃ circulating hot air drying tunnel and dry it for 3 minutes to completely cure the adhesive. Finally, cool it to room temperature with a cooling roller, roll it up, and cut it to the required size to obtain the moisture-absorbing and breathable medical bandage 1 of the present invention.

[0027] In step two, the parallel dual-nozzle electrospinning equipment uses a 21G parallel composite nozzle to ensure that the structural spinning solution and the functional spinning solution are in parallel contact at the nozzle but do not mix.

[0028] In step six, the average length of the pure cotton fiber is 38mm, the micronaire value is 4.0-4.5, the fineness is 1.5-1.8, the spandex filament specification is 40D, and the surface is treated with a light emulsifier or blended with a small amount of low melting point polyester fiber.

[0029] Example 1: A moisture-wicking and breathable medical bandage and its preparation method, comprising the following steps: Step 1: Dissolve 12g of polycaprolactone (PCL, molecular weight 80000) in 100ml of hexafluoroisopropanol to prepare a 12% (w / v) solution as the structural spinning solution. Dissolve 6g of nonionic surfactant (Pluronic F-127), 4g of polycaprolactone, and 0.5g of chitosan quaternary ammonium salt in a mixed solvent consisting of 90ml of hexafluoroisopropanol and 10ml of deionized water to prepare a 10.5% (w / v) solution as the functional spinning solution. Step 2: The structural spinning solution and functional spinning solution from Step 1 are loaded into the injection pump of a parallel dual-nozzle electrospinning device. The propulsion flow rates of the structural and functional spinning solutions are set to 1.0 mL / h and 0.5 mL / h, respectively. The receiving distance is fixed at 18 cm, the applied voltage is 20 kV, and spinning is carried out for 4 hours at a temperature of 25 ± 2℃ and a humidity of 60 ± 5% to obtain the inner layer 11 of the bandage. Step 3: Dissolve 7g polylactic acid and 3g polycaprolactone together in a mixed solvent of 70ml dichloromethane and 30ml N,N-dimethylformamide to prepare a spinning solution with a concentration of 10% (w / v). Propel the spinning solution at a flow rate of 1.2mL / h, with a receiving distance of 15cm, apply a voltage of 18kV, and control the ambient humidity below 40%. Collect a fiber cloth 121 with uniform thickness. Step 4: Fix the fiber cloth 21 from Step 3 flat on the worktable of the UV laser engraving machine. Under the laser parameters of 15W laser power, 500mm / s scanning speed and 50kHz frequency, etch a through-hole circular micro-hole array 122 with a hole diameter of 20μm and a hole spacing of 100μm on the fiber cloth. Clean the residual debris on the surface with a clean and dry airflow of 0.2MPa to obtain the intermediate layer substrate of the bandage. Step 5: Using a masking fixture, only one side of the bandage interlayer substrate obtained in Step 4 is exposed to the treatment chamber. A gas mixture consisting of 1% by volume of heptadecafluorodecyltrimethoxysilane vapor and 99% by volume of nitrogen is introduced into the chamber, and the mixture is treated at 120°C for 30 minutes. This makes the exposed surface superhydrophobic while the masked surface remains hydrophilic, thus constructing a hydrophilic-hydrophobic Janus structure as the bandage interlayer 12. Step 6: Mix 75wt% pure cotton fiber and 25wt% spandex filament evenly through a high-speed airflow web forming machine, lay the web, and then bond and reinforce it under hot air at 125℃ for 60s to obtain the outer layer 13 of the bandage. Step 7: Stack the inner bandage layer obtained in Step 2, the middle bandage layer obtained in Step 5, and the outer bandage layer obtained in Step 6 in sequence. Using an 80-mesh (approximately 200 lines / inch) anilox roller, transfer the 40% solids content water-based polyurethane adhesive in a discontinuous dot pattern between the middle and outer layers, and between the inner and middle layers. Control the adhesive application amount at 12±1g / m² (dry weight) by weight method. Feed the three layers into a flatbed hot press laminating machine and press them together for 20 seconds at 60℃ and 0.15MPa. Then, put the semi-finished product into a 60℃ circulating hot air drying tunnel to dry for 3 minutes to completely cure the adhesive. Finally, cool it to room temperature with a cooling roller, roll it up, and cut it to the required size to obtain the moisture-absorbing and breathable medical bandage 1 described in this invention.

[0030] In step two, the parallel dual-nozzle electrospinning equipment uses a 21G parallel composite nozzle to ensure that the structural spinning solution and the functional spinning solution are in parallel contact at the nozzle but do not mix.

[0031] In step six, the average length of the pure cotton fiber is 38mm, the micronaire value is 4.0-4.5, the fineness is 1.5-1.8, the spandex filament specification is 40D, and the surface is treated with a light emulsifier or blended with a small amount (about 2wt%) of low melting point polyester fiber.

[0032] The principle of this invention: In step one, chitosan quaternary ammonium salt is a cationic polymer, and bacterial cell membranes typically carry a negative charge. When bacteria come into contact with the inner fibrous layer, the chitosan quaternary ammonium salt, through positive and negative charge adsorption, disrupts the permeability and integrity of the bacterial cell membrane, leading to leakage of bacterial contents and death. This is a "contact" physical antibacterial mechanism, which is less likely to induce drug resistance. Figure 5 As shown, the bandage material exhibits a 98% inhibition rate against Staphylococcus aureus using the plate coating method.

[0033] In step two, chitosan quaternary ammonium salt is blended with polycaprolactone and other fibers during spinning, rather than being coated in a finishing process. This allows the antibacterial agent to be firmly locked inside the fiber and slowly migrate to the surface during use, achieving long-lasting antibacterial effect and avoiding rapid loss of the antibacterial agent.

[0034] In step one, Pluronic F-127, a water-sensitive block copolymer, was introduced and blended with polycaprolactone to form functional fibers. In its dry state, Pluronic F-127 is solid, working with polycaprolactone to maintain the stability of the inner layer of the bandage. When the bandage needs to be changed, healthcare workers moisten the edges with saline solution. Upon contact with water, Pluronic F-127 rapidly hydrates, swells, and transforms into a smooth gel. This in-situ formed gel creates an excellent lubricating barrier between the bandage and the wound, significantly reducing friction during peeling. This allows the bandage to easily and painlessly "slip" off the wound, achieving a smart transition from "firm adhesion" to "one-click peeling," perfectly addressing the clinical pain point of secondary injury.

[0035] In step five, the hydrophilic-hydrophobic Janus structure of the bandage's middle layer has its hydrophilic side facing the inner layer. This hydrophilic side is responsible for "capturing" water vapor molecules transmitted from the inner layer. The strong interaction between the hydrophilic material and water molecules allows for rapid capture and accumulation of moisture. The hydrophobic side faces the outer layer. Due to its hydrophobic nature, after capturing water vapor on the hydrophilic side, a humidity difference (capillary pressure difference) is created across the membrane. To achieve equilibrium, water molecules are forced to move directionally from the hydrophilic side to the hydrophobic side. This process acts like a one-way liquid pump, allowing only water to flow from the inside to the outside, efficiently "pumping" moisture to the outer layer while preventing reverse penetration of external liquids. This achieves a leap from "passive moisture absorption" to "active moisture conduction."

[0036] In step six, an elastic mesh nonwoven fabric made of spandex / cotton blend is used. Cotton fibers have good hydrophilicity and moisture absorption, allowing them to absorb moisture conducted from the middle layer of the bandage. After the moisture diffuses to the outer layer, it can convect fully with the air and evaporate quickly, preventing moisture buildup. At the same time, the mesh structure also ensures breathability at a macroscopic level. The addition of spandex gives the outer layer excellent stretch and resilience. This allows the bandage to wrap around the limbs easily like a rubber band, especially irregular areas such as joints. After bandaging, it fits tightly and is not easy to slip off, and patients do not feel restricted during movement, greatly improving comfort and convenience.

[0037] While the inner and middle layers of a bandage are highly functional, they are relatively weak in mechanical strength. The outer layer, acting as the structural framework, provides the necessary tensile strength and durability for the entire bandage, ensuring that it will not easily tear or deform during bandaging, immobilization, and daily activities, thus guaranteeing the product's reliability.

Claims

1. A moisture-absorbing and breathable medical bandage, characterized in that: It includes an inner layer (11), a middle layer (12), and an outer layer (13) of bandage that are sequentially combined. The inner layer (11) of the bandage is a composite fiber layer prepared by electrospinning with parallel dual nozzles, including fibers formed by structural spinning solution and fibers formed by functional spinning solution. The functional spinning solution contains nonionic surfactant Pluronic F-127, polycaprolactone and chitosan quaternary ammonium salt. The middle layer (12) of the bandage includes a fiber cloth (121) and a through-hole circular microporous array (122) disposed thereon, and the middle layer (12) of the bandage has a hydrophilic-hydrophobic Janus structure, wherein the hydrophilic surface faces the inner layer (11) of the bandage and the hydrophobic surface faces the outer layer (13) of the bandage. The outer layer (13) of the bandage is an elastic nonwoven fabric made of pure cotton fiber and spandex filaments that are web-formed by airflow and bonded by hot air.

2. The moisture-absorbing and breathable medical bandage according to claim 1, characterized in that: The structural spinning solution is a polycaprolactone solution in hexafluoroisopropanol with a concentration of 10-14% (w / v); the functional spinning solution is a solution of Pluronic F-127, polycaprolactone, and chitosan quaternary ammonium salt dissolved in a mixed solvent of hexafluoroisopropanol and deionized water with a total concentration of 9-12% (w / v).

3. The moisture-absorbing and breathable medical bandage according to claim 1, characterized in that: The fiber cloth (121) is made by electrospinning polylactic acid and polycaprolactone dissolved in a mixed solvent of dichloromethane and N,N-dimethylformamide, with a spinning solution concentration of 8-12% (w / v).

4. The moisture-absorbing and breathable medical bandage according to claim 1, characterized in that: The through-hole circular micropore array (122) has a pore diameter of 15-25μm and a pore spacing of 80-120μm, and is formed by ultraviolet laser engraving.

5. A moisture-absorbing and breathable medical bandage according to claim 1, characterized in that: The hydrophobic surface of the bandage intermediate layer (12) is formed by vapor deposition of a fluorinated silane vapor on one side, wherein the fluorinated silane is heptadecafluorodecyltrimethoxysilane.

6. A moisture-absorbing and breathable medical bandage according to claim 1, characterized in that: The mass ratio of pure cotton fiber to spandex filament in the outer layer (13) of the bandage is 70-80:20-30. The spandex filament is 40D and has been treated with emulsifier or blended with low melting point polyester fiber.

7. A method for preparing a moisture-absorbing and breathable medical bandage, used to prepare a moisture-absorbing and breathable medical bandage as described in any one of claims 1-6, characterized in that: Includes the following steps: Step 1: Dissolve polycaprolactone in hexafluoroisopropanol to prepare a 10-14% (w / v) solution as the structural spinning solution. Dissolve the nonionic surfactant (Pluronic F-127), polycaprolactone, and chitosan quaternary ammonium salt in a mixed solvent composed of hexafluoroisopropanol and deionized water to prepare a 9-12% (w / v) solution as the functional spinning solution. The mass ratio of the nonionic surfactant (Pluronic F-127), polycaprolactone, and chitosan quaternary ammonium salt dissolved in hexafluoroisopropanol is 12:8:1, and the volume ratio of hexafluoroisopropanol to deionized water is 9:

1. Step 2: The structural spinning solution and the functional spinning solution from Step 1 are loaded into the injection pump of the parallel dual-nozzle electrospinning equipment. The propulsion flow rates of the structural spinning solution and the functional spinning solution are set to 1.0 mL / h and 0.5 mL / h, respectively. The receiving distance is fixed at 18 cm. The applied voltage is 20 kV. Spinning is carried out in an environment with a temperature of 25 ± 2 ℃ and a humidity of 60 ± 5% to obtain the inner layer of the bandage (11). Step 3: Dissolve polylactic acid and polycaprolactone together in a mixed solvent of dichloromethane and N,N-dimethylformamide to prepare a spinning solution with a concentration of 8-12% (w / v). Propel the spinning solution at a flow rate of 1.2 mL / h, with a receiving distance of 15 cm, apply a voltage of 18 kV, and control the ambient humidity below 40%. Collect a fiber cloth (121) of uniform thickness. The mass ratio of polylactic acid to polycaprolactone is 7:3, and the volume ratio of dichloromethane to N,N-dimethylformamide is 7:

3. Step 4: The fiber cloth (121) from Step 3 is flattened and fixed on the worktable of the UV laser engraving machine. Under the laser parameters of 15W laser power, 500mm / s scanning speed and 50kHz frequency, a through-hole circular micro-hole array (122) with a hole diameter of 15-25μm and a hole spacing of 80-120μm is etched on the fiber cloth. The residual debris on the surface is cleaned with a clean and dry airflow of 0.2MPa to obtain the intermediate layer substrate of the bandage. Step 5: Using a masking fixture, only one side of the bandage interlayer substrate obtained in Step 4 is exposed to the treatment chamber. A gas mixture consisting of 1% by volume of heptadecafluorodecyltrimethoxysilane vapor and 99% by volume of nitrogen is introduced into the chamber and treated at 120°C for 30 minutes. This makes the exposed surface superhydrophobic while the masked surface remains hydrophilic, thus constructing a hydrophilic-hydrophobic Janus structure as the bandage interlayer (12). Step 6: The pure cotton fiber and the spandex filament are evenly mixed by a high-speed airflow web forming machine, and after web formation, they are bonded and reinforced under hot air at 125℃ for 60s to obtain the outer layer of the bandage (13). The mass ratio of pure cotton fiber to spandex filament is 70-80:20-30. Step 7: Stack the inner layer (11) of the bandage obtained in Step 2, the middle layer (12) of the bandage obtained in Step 5, and the outer layer (13) of the bandage obtained in Step 6 in sequence. Use an 80-mesh anilox roller to transfer water-based polyurethane adhesive with a solid content of 40% in the form of intermittent dots between the middle layer and the outer layer, and between the inner layer and the middle layer. Control the amount of adhesive applied by weight method at 12±1g / m². Feed the three layers of materials into a flat hot press laminating machine and press them for 20 seconds at a temperature of 60℃ and a pressure of 0.15MPa. Then, put the semi-finished product into a circulating hot air drying tunnel at 60℃ and dry it for 3 minutes to completely cure the adhesive. Finally, cool it to room temperature with a cooling roller, roll it up, and cut it into the required size to obtain the moisture-absorbing and breathable medical bandage (1) of the present invention.

8. The method for preparing a moisture-absorbing and breathable medical bandage according to claim 7, characterized in that: In step two, the parallel dual-nozzle electrospinning equipment uses a 21G parallel composite nozzle to ensure that the structural spinning solution and the functional spinning solution are in parallel contact at the nozzle but do not mix.

9. The method for preparing a moisture-absorbing and breathable medical bandage according to claim 7, characterized in that: In step six, the average length of the pure cotton fiber is 38mm, the micronaire value is 4.0-4.5, the fineness is 1.5-1.8, the spandex filament specification is 40D, and the surface is treated with a light emulsifier or blended with a small amount of low melting point polyester fiber.

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