Antibacterial moisture-absorbing breathable sanitary towel and preparation method thereof

Abstract

The invention discloses an antibacterial moisture-absorbing breathable sanitary napkin and a preparation method thereof, and relates to the technical field of sanitary napkins, the preparation method comprises the following steps: mixing a chitosan microcapsule essential oil dispersion liquid, the essential oil dispersion liquid and a quercetin solution, and ultrasonically spraying the mixture on the surface of a polycaprolactone nanofiber membrane to obtain an antibacterial breathable surface layer; uniformly mixing super absorbent polymer powder and nano cellulose powder, adding a cross-linking agent, uniformly stirring, and carrying out hot press molding to obtain a gradient moisture absorption middle layer; adding a mixed solution of sodium alginate and cellulose nanocrystals into a calcium chloride solution, drying and crushing to obtain a water-locking breathable bottom layer; the antibacterial breathable surface layer, the gradient moisture absorption middle layer and the water locking breathable bottom layer are sequentially stacked from top to bottom, hot pressing and cooling are conducted, and the antibacterial moisture absorption breathable sanitary towel is obtained.

Description

Technical Field

[0001] This invention relates to the field of sanitary napkin technology, specifically to an antibacterial, moisture-wicking, and breathable sanitary napkin and its preparation method. Background Technology

[0002] With increasing awareness of women's health, the functional requirements for sanitary napkins have expanded from basic absorbency to include antibacterial properties, breathability, leak prevention, and odor control. Existing sanitary napkins generally suffer from the following problems: limited antibacterial performance, easily leading to the growth of harmful bacteria such as E. coli and Staphylococcus aureus during use, increasing the risk of reproductive system infections; insufficient synergy between absorbency and moisture retention, with some products exhibiting slow absorbency leading to liquid accumulation, or poor moisture retention causing backflow; poor breathability, resulting in stuffiness after prolonged wear; difficulty in effectively addressing odor issues, affecting the user experience; and insufficient stability of the bottom layer structure, easily deforming under pressure, leading to side leakage or breakage. These defects seriously affect the safety and comfort of sanitary napkins. Therefore, developing a sanitary napkin that combines antibacterial properties, high-efficiency moisture absorption, strong water retention, breathability, and leak prevention has become an urgent need for the industry. Summary of the Invention

[0003] The purpose of this invention is to provide an antibacterial, moisture-wicking, and breathable sanitary napkin and its preparation method, so as to solve the problems raised in the prior art.

[0004] To achieve the aforementioned objective, the present invention provides the following technical solution: A method for preparing an antibacterial, moisture-wicking, and breathable sanitary napkin includes the following steps: S1: Preparing an antibacterial and breathable surface layer: Polycaprolactone, zinc oxide nanoparticles, and curcumin are added to acetone, stirred evenly, to obtain an electrospinning solution, and electrospinned to obtain a nanofiber membrane; Furthermore, in the preparation process of the electrospinning solution, the mass ratio of polycaprolactone: zinc oxide nanoparticles: curcumin is (15-20):(3-7):(1-3); Furthermore, the zinc oxide nanoparticles have a particle size of <100nm; The electrospinning parameters include a voltage of 18-22kV, a needle-to-collecting plate distance of 12-18cm, a flow rate of 4-6mL / h, an ambient temperature of 25-30℃, and a humidity of 40-60%. Mix the essential oil and β-cyclodextrin-grafted chitosan evenly, add Tween 80, emulsify for 15-20 minutes, freeze dry to obtain microcapsule essential oil; Furthermore, in the preparation process of the microcapsule essential oil, the mass ratio of mixed essential oil to β-cyclodextrin grafted chitosan is (3-5):1; the amount of Tween 80 added is 0.4-0.6 wt% of the mixed essential oil; the mixture is prepared by mixing lavender oil, tea tree oil and rose oil in a mass ratio of (2-3):(2-3):1. Furthermore, the freeze-drying temperature is -80 to -85°C, and the time is 20 to 28 hours; Microcapsule essential oils were added to deionized water to obtain an essential oil dispersion; the essential oil dispersion and quercetin solution were mixed and ultrasonically sprayed onto the surface of a nanofiber membrane, and then vacuum dried at 40-50℃ to obtain an antibacterial and breathable surface layer. Furthermore, the concentration of the essential oil dispersion is 10-15 g / L, and the concentration of the quercetin solution is 30-50 g / L; the volume ratio of the essential oil dispersion to the quercetin solution is 1:1. Furthermore, the solvent for the quercetin solution is ethanol; Furthermore, the ultrasonic spraying process parameters include a power of 4-5W, a flow rate of 0.4-0.6mL / h, a nozzle distance of 8-12cm, and 2-4 spraying layers. S2: Preparation of gradient hygroscopic middle layer: Microcrystalline cellulose is added to a 40wt% sulfuric acid solution, heated to 65-75℃ for 1.5-2.5h for hydrolysis, neutralized, filtered, and spray-dried to obtain nanocellulose powder; Furthermore, in the preparation process of the nanocellulose powder, the mass ratio of microcrystalline cellulose to 40wt% sulfuric acid solution is 1:10; Acrylic acid was added to deionized water, sodium hydroxide was added to adjust the pH to 6.0-6.2, trimethylolpropane triacrylate was added, sodium persulfate and sodium metabisulfite were added under a nitrogen atmosphere, and the mixture was heated to 63-67℃ to gel, and then further heated to 78-82℃ to polymerize for 4-5 hours. The mixture was then pulverized and sieved to obtain a superabsorbent polymer powder. Furthermore, the components in the superabsorbent polymer powder, by mass percentage, include 100-120g of acrylic acid, 240-260g of deionized water, 40-42g of sodium hydroxide, 0.006-0.008g of trimethylolpropane triacrylate, 0.18-0.22g of sodium persulfate, and 0.14-0.18g of sodium metabisulfite; Superabsorbent polymer powder and nanocellulose powder are mixed evenly, a crosslinking agent is added, the mixture is stirred evenly, and then hot-pressed to obtain a gradient moisture-absorbing middle layer. Furthermore, in the preparation process of the gradient hygroscopic middle layer, the mass ratio of superabsorbent polymer powder to nanocellulose powder is (70-90):(10-30); the amount of crosslinking agent added is 0.5-2 wt% of the total mass of superabsorbent polymer powder and nanocellulose powder. Furthermore, the crosslinking agent is prepared by mixing calcium chloride and aluminum chloride at a mass ratio of (2-3):1; Furthermore, the hot pressing temperature is 60-70℃; S3: Preparation of water-locking and breathable bottom layer: Sodium alginate and cellulose nanocrystals are added to deionized water, stirred for 10-12 hours, and ultrasonically dispersed to obtain a mixture; the mixture is added to calcium chloride solution, reacted for 30-60 minutes, washed, dried at 55-65℃ for 24 hours, pulverized, and further heated to 78-82℃ for vacuum drying to obtain the water-locking and breathable bottom layer; Furthermore, in the preparation of the mixture, the mass ratio of sodium alginate to cellulose nanocrystals is (96-99):(1-4); the concentration of the mixture is 6-10 w / v; and the concentration of the calcium chloride solution is 0.25-0.5 w / v. S4: Stack the antibacterial and breathable top layer, the gradient moisture-absorbing middle layer, and the water-locking and breathable bottom layer from top to bottom, heat press, and cool to obtain an antibacterial moisture-absorbing and breathable sanitary napkin.

[0005] Furthermore, in the preparation process of the antibacterial, moisture-wicking and breathable sanitary napkin, the mass ratio of the antibacterial and breathable surface layer: the gradient moisture-wicking middle layer: the water-locking and breathable bottom layer is 1:(3-5):(1-2); the hot-pressing temperature is 80-90℃, the pressure is 0.3-0.5MPa, and the time is 3-5min.

[0006] Compared with the prior art, the beneficial effects of the present invention are: 1. The zinc oxide nanoparticles in the antibacterial and breathable surface layer prepared by this invention generate reactive oxygen species in the body fluid environment, which oxidize and destroy lipids and proteins on the bacterial cell membrane, leading to cell lysis; at the same time, curcumin binds with Zn through its β-diketone structure. 2+ A stable complex is formed, enhancing the loading stability of ZnO on the fiber membrane. Simultaneously, the aromatic ring structure of curcumin inserts into the bacterial DNA double strand, inhibiting nucleic acid synthesis, and exerting a dual effect of reactive oxygen species oxidation and nucleic acid inhibition with zinc oxide. The phenolic hydroxyl groups in the quercetin molecule provide hydrogen atoms, neutralizing free radicals generated by bacterial metabolism and disrupting their metabolic balance. Quercetin forms hydrogen bonds with the amino groups of the chitosan nonwoven fabric, achieving slow release and prolonging the antibacterial effect. Its hydrophobic properties also reduce bacterial adhesion to the surface. β-cyclodextrin-grafted chitosan, used as the microcapsule wall material, encapsulates essential oil components in its hollow structure, preventing essential oil volatilization and achieving long-lasting sustained release. Active components in the mixed essential oils, including linalool in lavender oil and eucalyptol in tea tree oil, disrupt bacterial cell membrane permeability, inhibiting fungal hyphal growth, and the aromatic components of the essential oils neutralize odors. The mechanical strength of polycaprolactone fibers supports the surface structure, preventing the fibers from collapsing and blocking the air channels after absorbing moisture. At the same time, the hydrophobicity of polycaprolactone reduces surface liquid residue and improves the anti-sticking effect.

[0007] 2. The nanocellulose prepared in the gradient hygroscopic middle layer of this invention has a high specific surface area and abundant hydrophilic hydroxyl groups, which rapidly adsorb liquid and form capillary permeation channels, accelerating the diffusion of liquid into the interior of the superabsorbent polymer (SAP). The nanocellulose is dispersed in the SAP powder, filling the gaps between SAP particles and forming a gradient pore structure, preventing liquid from accumulating on the surface. Hot pressing at 60-70℃ tightly binds the SAP and nanocellulose together, forming a continuous hygroscopic-water-locking network, while controlling the porosity to ensure rapid liquid penetration and prevent a decrease in water-locking capacity.

[0008] 3. In the water-locking and breathable bottom layer prepared by this invention, sodium alginate and cellulose nanocrystals are cross-linked with calcium chloride solution to form a three-dimensional gel network. The carboxyl groups of the nanocrystals form hydrogen bonds with water molecules, which firmly lock in moisture. The cross-linked gel structure has good elasticity and can recover its original shape after being compressed, avoiding side leakage caused by deformation of the bottom layer. The cellulose nanocrystals act as a skeleton reinforcing agent, controlling the pore size of the hydrogel, ensuring that liquid permeates from the upper layer to the bottom layer and is locked in, while also allowing gas to pass through, thus achieving a balance between water locking and breathability. The cellulose nanocrystals enhance the mechanical strength of the bottom layer, preventing leakage caused by damage to the bottom layer during use. Detailed Implementation

[0009] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0010] Example 1: A method for preparing an antibacterial, moisture-wicking and breathable sanitary napkin: S1: Preparation of antibacterial and breathable surface layer: 18g of polycaprolactone, 5g of zinc oxide nanoparticles and 2g of curcumin are added to 150mL of acetone and stirred evenly to obtain an electrospinning solution. Electrospinning is then performed to obtain a nanofiber membrane. The electrospinning parameters include a voltage of 20kV, a needle-to-collecting plate distance of 15cm, a flow rate of 5mL / h, an ambient temperature of 28℃, and a humidity of 50%. Mix 20g lavender oil, 20g tea tree oil, and 8g rose oil evenly to obtain a mixed essential oil; mix the mixed essential oil with 12g β-cyclodextrin grafted chitosan evenly, add 0.24g Tween 80, emulsify for 18min, freeze dry at -80℃ and -0.1Mpa, pulverize and sieve to obtain microcapsule essential oil; 12g of microcapsule essential oil was added to 1000g of deionized water to obtain an essential oil dispersion; the essential oil dispersion and 40g / L quercetin solution were mixed at a volume ratio of 1:1, ultrasonically sprayed onto the surface of a nanofiber membrane, and vacuum dried at 40℃ and -0.09MPa to obtain an antibacterial and breathable surface layer. The ultrasonic spraying process parameters include a power of 4.5W, a flow rate of 0.5mL / h, a nozzle distance of 10cm, and a number of spraying layers of 3. S2: Preparation of gradient hygroscopic middle layer: Add 30g microcrystalline cellulose to 300g 40wt% sulfuric acid solution, heat to 65℃ for 1.5h for hydrolysis, neutralize, filter, and spray dry to obtain nanocellulose powder; Add 100g of acrylic acid to 240g of deionized water, add 40g of sodium hydroxide to adjust the pH to 6.1, add 0.006g of trimethylolpropane triacrylate, add 0.18g of sodium persulfate and 0.14g of sodium metabisulfite under a nitrogen atmosphere, heat to 63℃ to gel, further heat to 78℃ to polymerize for 4h, pulverize, and sieve to obtain a superabsorbent polymer powder; Mix 70g of superabsorbent polymer powder and 30g of nanocellulose powder evenly, add 0.25g of crosslinking agent, stir evenly, and hot press at 65℃ and 0.3MPa to obtain a gradient moisture-absorbing middle layer. S3: Preparation of the water-locking and breathable bottom layer: 98g of sodium alginate and 2g of cellulose nanocrystals were added to 1225mL of deionized water, stirred for 11h, and ultrasonically dispersed to obtain a mixed solution; the mixed solution was added to 1200mL of 0.3w / v% calcium chloride solution, reacted for 30min, washed, dried at 55℃ for 24h, pulverized, and further heated to 78℃ for vacuum drying to obtain the water-locking and breathable bottom layer; S4: Stack the antibacterial and breathable top layer, gradient moisture-absorbing middle layer, and water-locking and breathable bottom layer from top to bottom, heat press at 80℃ and 0.3MPa for 3 minutes, and cool to obtain an antibacterial moisture-absorbing and breathable sanitary napkin; In the preparation process of the antibacterial, moisture-wicking and breathable sanitary napkin, the mass ratio of the antibacterial and breathable top layer, the gradient moisture-wicking middle layer, and the water-locking and breathable bottom layer is 1:4:1.5.

[0011] Example 2: A method for preparing an antibacterial, moisture-wicking and breathable sanitary napkin: S2: Preparation of a gradient moisture-wicking middle layer: 30g of microcrystalline cellulose is added to 300g of 40wt% sulfuric acid solution, heated to 65℃ for 1.5h for hydrolysis, neutralized, filtered, and spray-dried to obtain nanocellulose powder; Add 100g of acrylic acid to 240g of deionized water, add 40g of sodium hydroxide to adjust the pH to 6.1, add 0.006g of trimethylolpropane triacrylate, add 0.18g of sodium persulfate and 0.14g of sodium metabisulfite under a nitrogen atmosphere, heat to 63℃ to gel, further heat to 78℃ to polymerize for 4h, pulverize, and sieve to obtain a superabsorbent polymer powder; Mix 80g of superabsorbent polymer powder and 20g of nanocellulose powder evenly, add 0.25g of crosslinking agent, stir evenly, and hot press at 65℃ and 0.3MPa to obtain a gradient moisture-absorbing middle layer. The remaining steps are the same as in Example 1.

[0012] Example 3: A method for preparing an antibacterial, moisture-wicking, and breathable sanitary napkin: S3: Preparation of the water-locking and breathable bottom layer: 96g of sodium alginate and 4g of cellulose nanocrystals were added to 1225mL of deionized water, stirred for 11h, and ultrasonically dispersed to obtain a mixed solution; the mixed solution was added to 1200mL of 0.3w / v% calcium chloride solution, reacted for 30min, washed, dried at 55℃ for 24h, pulverized, and further heated to 78℃ for vacuum drying to obtain the water-locking and breathable bottom layer; The remaining steps are the same as in Example 1.

[0013] Example 4: A method for preparing an antibacterial, moisture-wicking and breathable sanitary napkin: S2: Preparation of a gradient moisture-wicking middle layer: 30g of microcrystalline cellulose is added to 300g of 40wt% sulfuric acid solution, heated to 65℃ for 1.5h for hydrolysis, neutralized, filtered, and spray-dried to obtain nanocellulose powder; Add 100g of acrylic acid to 240g of deionized water, add 40g of sodium hydroxide to adjust the pH to 6.1, add 0.006g of trimethylolpropane triacrylate, add 0.18g of sodium persulfate and 0.14g of sodium metabisulfite under a nitrogen atmosphere, heat to 63℃ to gel, further heat to 78℃ to polymerize for 4h, pulverize, and sieve to obtain a superabsorbent polymer powder; Mix 90g of superabsorbent polymer powder and 10g of nanocellulose powder evenly, add 0.25g of crosslinking agent, stir evenly, and hot press at 65℃ and 0.3MPa to obtain a gradient moisture-absorbing middle layer. S3: Preparation of the water-locking and breathable bottom layer: 99g of sodium alginate and 1g of cellulose nanocrystals were added to 1225mL of deionized water, stirred for 11h, and ultrasonically dispersed to obtain a mixed solution; the mixed solution was added to 1200mL of 0.3w / v% calcium chloride solution, reacted for 30min, washed, dried at 55℃ for 24h, pulverized, and further heated to 78℃ for vacuum drying to obtain the water-locking and breathable bottom layer; The remaining steps are the same as in Example 1.

[0014] Comparative Example 1: A method for preparing an antibacterial, moisture-wicking and breathable sanitary napkin: S1: Preparation of antibacterial and breathable surface layer: 18g of polycaprolactone, 5g of zinc oxide nanoparticles and 2g of curcumin are added to 150mL of acetone and stirred evenly to obtain an electrospinning solution. Electrospinning is then performed to obtain a nanofiber membrane. The electrospinning parameters include a voltage of 20kV, a needle-to-collecting plate distance of 15cm, a flow rate of 5mL / h, an ambient temperature of 28℃, and a humidity of 50%. Mix 20g lavender oil, 20g tea tree oil, and 8g rose oil evenly to obtain a mixed essential oil; mix the mixed essential oil with 12g β-cyclodextrin grafted chitosan evenly, add 0.24g Tween 80, emulsify for 18min, freeze dry at -80℃ and -0.1Mpa, pulverize and sieve to obtain microcapsule essential oil; 12g of microcapsule essential oil was added to 1000g of deionized water to obtain an essential oil dispersion; the essential oil dispersion was ultrasonically sprayed onto the surface of a nanofiber membrane and vacuum dried at 40℃ and -0.09MPa to obtain an antibacterial and breathable surface layer. The ultrasonic spraying process parameters include a power of 4.5W, a flow rate of 0.5mL / h, a nozzle distance of 10cm, and a number of spraying layers of 3. The remaining steps are the same as in Example 1.

[0015] Comparative Example 2: A method for preparing an antibacterial, moisture-wicking, and breathable sanitary napkin: S2: Preparation of a gradient moisture-wicking middle layer: 30g of microcrystalline cellulose was added to 300g of 40wt% sulfuric acid solution, heated to 65℃ for 1.5h for hydrolysis, neutralized, filtered, and spray-dried to obtain nanocellulose powder; Add 100g of acrylic acid to 240g of deionized water, add 40g of sodium hydroxide to adjust the pH to 6.1, add 0.006g of trimethylolpropane triacrylate, add 0.18g of sodium persulfate and 0.14g of sodium metabisulfite under a nitrogen atmosphere, heat to 63℃ to gel, further heat to 78℃ to polymerize for 4h, pulverize, and sieve to obtain a superabsorbent polymer powder; Mix 100g of superabsorbent polymer powder evenly, add 0.25g of crosslinking agent, stir evenly, and hot press at 65℃ and 0.3MPa to obtain a gradient moisture-absorbing middle layer; The remaining steps are the same as in Example 1.

[0016] Comparative Example 3: A preparation method for an antibacterial, moisture-wicking, and breathable sanitary napkin: S3: Preparation of the water-locking and breathable bottom layer: 100g of sodium alginate was added to 1225mL of deionized water, stirred for 11h, and ultrasonically dispersed to obtain a mixture; the mixture was added to 1200mL of 0.3w / v% calcium chloride solution, reacted for 30min, washed, dried at 55℃ for 24h, pulverized, and further heated to 78℃ for vacuum drying to obtain the water-locking and breathable bottom layer; The remaining steps are the same as in Example 1.

[0017] Performance testing: Antibacterial performance: tested according to GB / T20944.3-2008; Moisture absorption rate: Simulated menstrual blood formula: 10g NaCl + 40g Na2CO3 + 1g sodium benzoate + 5g CMC + 140mL glycerin + 860g distilled water, weighing method: record the water absorption of 20mL simulated menstrual blood from 0-300s. Air permeability: Tested using an air permeability meter; Water retention rate: The residual water volume was calculated by centrifuging at 1400 rpm for 3 min after liquid aspiration. Leakage prevention performance: Simulating usage scenario, tilt the sanitary napkin at a 30° angle, add 30mL of simulated menstrual blood, and record the leakage amount; Mechanical strength: Tested according to GB / T3923.1-2013. Tensile test: 50mm×100mm sample, tensile rate 10mm / min.

[0018] The antibacterial properties are shown in Table 1 below.

[0019] Table 1

[0020] The moisture absorption, water retention, and breathability properties are shown in Table 2 below.

[0021] Table 2

[0022] The mechanical properties are shown in Table 3 below.

[0023] Table 3

[0024] in conclusion: The absence of quercetin in Comparative Example 1 resulted in a decrease in antibacterial rate and mechanical properties; the absence of nanocellulose in the gradient middle layer in Comparative Example 2 resulted in a decrease in moisture absorption rate, water retention rate, air permeability, and leakage prevention; and the absence of cellulose nanocrystals in the water-locking bottom layer in Comparative Example 3 resulted in a decrease in moisture absorption rate, water retention rate, air permeability, and leakage prevention.

[0025] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention.

Claims

1. A method for preparing an antibacterial type absorbent and vapor permeable sanitary napkin, characterized by: The method comprises the following steps: S1: preparing an antibacterial and breathable surface layer: adding chitosan microcapsule essential oil into deionized water to obtain an essential oil dispersion; mixing the essential oil dispersion and a quercetin solution, and ultrasonic spraying the mixture on the surface of a polycaprolactone nanofiber membrane to obtain the antibacterial and breathable surface layer; S2: preparing a gradient moisture absorption middle layer: uniformly mixing superabsorbent polymer powder and nanocellulose powder, adding a crosslinking agent, and uniformly stirring to obtain the gradient moisture absorption middle layer; S3: preparing a water-locking and breathable bottom layer: adding sodium alginate and cellulose nanocrystals into deionized water, stirring, and ultrasonic dispersing to obtain a mixed solution; adding the mixed solution into a calcium chloride solution, reacting for 30-60 min, washing, drying at 55-65 DEG C for 24 h, crushing, and further heating to 78-82 DEG C for vacuum drying to obtain the water-locking and breathable bottom layer; S4: stacking the antibacterial and breathable surface layer, the gradient moisture absorption middle layer, and the water-locking and breathable bottom layer from top to bottom, hot pressing, and cooling to obtain the antibacterial and moisture-absorbing and breathable sanitary napkin.

2. The process for preparing an anti-bacterial type absorbent and vapor permeable sanitary napkin as claimed in claim 1, wherein: The concentration of the essential oil dispersion is 10-15 g / L, and the concentration of the quercetin solution is 30-50 g / L; the volume ratio of the essential oil dispersion to the quercetin solution is 1:

1.

3. The process for preparing an anti-bacterial type absorbent and vapor permeable sanitary napkin as claimed in claim 1, wherein: The preparation method of the polycaprolactone nanofiber membrane comprises the following steps: adding polycaprolactone, zinc oxide nanoparticles, and curcumin into acetone, uniformly stirring to obtain an electrospinning solution, and electrospinning to obtain the polycaprolactone nanofiber membrane. During the preparation of the electrospinning solution, the mass ratio of polycaprolactone to zinc oxide nanoparticles to curcumin is (15-20):(3-7):(1-3).

4. The process for preparing an anti-bacterial type of absorbent and vapor permeable sanitary napkin as claimed in claim 1, wherein: The preparation method of the chitosan microcapsule essential oil comprises the following steps: uniformly mixing mixed essential oil and β-cyclodextrin grafted chitosan, adding Tween 80, emulsifying for 15-20 min, and freeze-drying to obtain the chitosan microcapsule essential oil. During the preparation of the chitosan microcapsule essential oil, the mass ratio of mixed essential oil to β-cyclodextrin grafted chitosan is (3-5):1; the amount of Tween 80 added is 0.4-0.6 wt% of the mixed essential oil; and the mixed essential oil is prepared by mixing lavender oil, tea tree oil, and rose oil at a mass ratio of (2-3):(2-3):

1.

5. The process for preparing an anti-bacterial type of absorbent and vapor permeable sanitary napkin as claimed in claim 1, wherein: The preparation method of the nanocellulose powder comprises the following steps: adding microcrystalline cellulose into a 40 wt% sulfuric acid solution, heating to 65-75 DEG C for hydrolysis for 1.5-2.5 h, neutralizing, filtering, and spray drying to obtain the nanocellulose powder. During the preparation of the nanocellulose powder, the mass ratio of microcrystalline cellulose to the 40 wt% sulfuric acid solution is 1:

10.

6. The process for preparing an anti-bacterial type of absorbent and vapor permeable sanitary napkin as claimed in claim 1, wherein: The preparation method of the superabsorbent polymer powder comprises the following steps: adding acrylic acid into deionized water, adding sodium hydroxide to adjust the pH to 6.0-6.2, adding trimethylolpropane triacrylate, adding sodium persulfate and sodium metabisulfite under a nitrogen atmosphere, gelating by heating to 63-67 DEG C, further polymerizing by heating to 78-82 DEG C for 4-5 h, crushing, and sieving to obtain the superabsorbent polymer powder. The high water-absorbing polymer powder includes 100-120g of acrylic acid, 240-260g of deionized water, 40-42g of sodium hydroxide, 0.006-0.008g of trimethylolpropane triacrylate, 0.18-0.22g of sodium persulfate and 0.14-0.18g of sodium pyrosulfite.

7. The process for preparing an anti-bacterial type of absorbent and vapor permeable sanitary napkin as claimed in claim 1, wherein: In the preparation process of the gradient moisture-absorbing middle layer, the mass ratio of the high water-absorbing polymer powder to the nanocellulose powder is (70-90):(10-30), and the crosslinking agent is added in an amount of 0.5-2wt% of the total mass of the high water-absorbing polymer powder and the nanocellulose powder. The crosslinking agent is calcium chloride and aluminum chloride configured in a mass ratio of (2-3):

1.

8. A process for the preparation of an anti-microbial absorbent and vapor transmissive sanitary napkin as claimed in claim 1, wherein: In the preparation process of the mixed solution, the mass ratio of sodium alginate to cellulose nanocrystals is (96-99):(1-4), the concentration of the mixed solution is 6-10w / v%, and the concentration of the calcium chloride solution is 0.25-0.5w / v%.

9. The process for preparing an anti-bacterial type of absorbent and vapor permeable sanitary napkin as claimed in claim 1, wherein: In the preparation process of the antibacterial moisture-absorbing and air-permeable sanitary napkin, the mass ratio of the antibacterial and air-permeable surface layer to the gradient moisture-absorbing middle layer to the water-locking and air-permeable bottom layer is 1:(3-5):(1-2). The hot-pressing temperature is 80-90℃, the pressure is 0.3-0.5MPa, and the time is 3-5min. 10.An antibacterial moisture-absorbing and air-permeable sanitary napkin prepared by the preparation method of the antibacterial moisture-absorbing and air-permeable sanitary napkin according to any one of claims 1-9.

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