Double-wing rubber sanitary towel and preparation method thereof

Abstract

The invention discloses a double-wing rubber sanitary towel and a preparation method thereof. The sanitary napkin with the double protection wing rubber strips comprises a sanitary napkin body, the sanitary napkin body is provided with an absorption core body, and the absorption core body is composed of an upper-layer PE perforated film, a middle-layer resin particle layer and a lower-layer flow guide non-woven fabric, so that a sandwich structure is formed. The invention discloses a preparation method of a double-wing adhesive sanitary towel. The preparation method comprises the following steps: S1, preparing a gradient pressure-sensitive adhesive; s2, preparing a release paper composite base material; s3, preparing an absorption core body; s4, coating a gradient adhesive layer; s5, dynamically folding and positioning; s6, intelligent slitting detection is carried out; and S7, product assembling. The gradient pressure-sensitive adhesive layer is combined with the microcapsule phase-change material, the strong adhesive force between the protection wings and the underpants is ensured, meanwhile, the skin contact viscosity is reduced, the allergy risk is reduced, the chitin modified SAP particles are matched with the air-laid flow guide layer, the liquid diffusion speed is greatly increased, and lateral seepage is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sanitary napkins, and particularly to a double-strip wing glue sanitary napkin and a preparation method thereof. Background Art

[0002] At present, commercially available sanitary napkins generally adopt a single-sided or double-sided wing structure to prevent side leakage. The core technical difficulties lie in the fitting stability between the wings and the underwear, the evenness of the glue layer coating, and the efficiency of the production process.

[0003] The existing technologies mainly have the following problems: 1. Design defects in the wing glue layer. Directly coating with a single-viscosity pressure-sensitive adhesive easily leads to problems such as "over-sticky discomfort" or "insufficient fitting"; 2. Insufficient environmental protection of the release paper. It is non-degradable and difficult to recycle. Commonly used PE release paper does not meet the current environmental protection requirements, and it needs to correspond to the double strips of wings one by one, with high requirements for slitting accuracy and increased equipment complexity; 3. Absorption performance needs to be improved. Using traditional SAP particles, the water absorption ratio is only 300-400%, and the liquid diffusion speed is slow, which easily leads to side seepage. Summary of the Invention

[0004] The purpose of the present invention is to solve the defects existing in the prior art, and to propose a double-strip wing glue sanitary napkin and a preparation method thereof.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A double-strip wing glue sanitary napkin, comprising a sanitary napkin body, the sanitary napkin body having an absorption core, the absorption core being composed of an upper PE punched film, a middle resin particle layer, and a lower flow guiding non-woven fabric, forming a sandwich structure, and the water absorption ratio of the resin particle layer being not less than 500%;

[0007] A pair of wings symmetrically arranged on both sides of the sanitary napkin body, a double-strip pressure-sensitive adhesive layer is provided at the connection between the wings and the sanitary napkin body, the pressure-sensitive adhesive layer being composed of an outer high-viscosity area and an inner low-viscosity area to form a gradient structure, wherein the viscosity of the outer high-viscosity area is greater than or equal to 3000 mPa·s, and the viscosity of the inner low-viscosity area is less than or equal to 1500 mPa·s;

[0008] Release paper, the release paper being a substrate composed of polylactic acid and bamboo fiber compounded in a mass ratio of 7:3, with a nano-SiO2 release coating coated on its surface, the coating solid content being 1.5-2.5%, the release paper thickness being 35-45 μm, and an anti-sticking positioning line with a width of 0.5-1.2 mm being provided on the side of the release paper in contact with the wing, and the distance between adjacent positioning lines being adapted to the folding angle of the wing of 85°-95°.

[0009] Preferably, microcapsule phase change materials are uniformly dispersed in the pressure-sensitive adhesive layer. The particle size of the microcapsule phase change materials is 10 - 30 μm, and their loading amount is 5 - 8% of the total mass of the pressure-sensitive adhesive layer.

[0010] Preferably, the aperture of the PE perforated film is 0.1 - 0.3 mm, and the punching rate is 15 - 25%; the unit area mass of the flow guiding non-woven fabric is 30 - 50 g / m 2 。

[0011] Preferably, the lipid particle layer is modified with chitin. The particle size of the chitin-modified particles is 150 - 200 μm, and the unit area mass in the absorbent core is 80 - 120 g / m 2 。

[0012] Preferably, the length of the wing is 80 - 120 mm, the width is 20 - 30 mm, and the fitting length with the main body of the sanitary napkin after folding is 40 - 60 mm.

[0013] A preparation method of a double-strip wing adhesive sanitary napkin includes the following steps:

[0014] S1. Preparation of gradient pressure-sensitive adhesive: Styrene-isoprene-styrene block copolymer and tackifying resin are mixed according to a mass ratio of 1:0.8 - 1.2, and then menthol microcapsules with a particle size of 10 - 30 μm are added. Melting and blending are carried out at a temperature of 150 - 180 °C through a screw extruder to prepare a gradient pressure-sensitive adhesive;

[0015] S2. Preparation of release paper composite substrate: Poly(lactic acid) and bamboo fiber are formed into base paper by wet papermaking process according to a mass ratio of 7:3. The base paper is immersed in nano-SiO2 sol for dip coating, and then hot press shaping is carried out at a temperature of 110 - 130 °C to obtain a release paper composite substrate;

[0016] S3. Preparation of absorbent core: By air-laying process, chitin-modified SAP particles and flow guiding non-woven fabric are compounded to obtain an absorbent core composite layer with a unit area mass of 80 - 120 g / m 2 ;

[0017] S4. Coating of gradient adhesive layer: The prepared gradient pressure-sensitive adhesive is synchronously coated on both sides of the release paper using a microgravure coater, and the thickness difference of the adhesive layer is controlled within the range of ±0.01 mm;

[0018] S5. Dynamic folding and positioning: The wing is folded in half by using a negative pressure conveying roller. The folding angle of the wing is monitored in real time through a pressure sensor, and the control accuracy of the folding angle is maintained within ±0.5°. At the same time, an air flow auxiliary nozzle with an air pressure of 0.2 - 0.3 MPa is used to assist in aligning the wing, and the vacuum degree of the negative pressure conveying roller is maintained at -0.05 to -0.08 MPa;

[0019] S6. Intelligent slitting detection, online detecting the defects of the adhesive layer through a hyperspectral imaging system, and dynamically adjusting the slitting position by linking the servo cutter head;

[0020] S7. Product assembly, assembling the release paper coated with the adhesive layer, the folded and positioned wing, the prepared absorbent core and other components to form a finished double-strip wing adhesive sanitary napkin, wherein the matching error between the slitting speed of the release paper and the conveying speed of the sanitary napkin body is controlled within ≤±0.5 mm / s, and the fitting accuracy between the release paper and the wing after slitting is controlled within ≤±0.3 mm.

[0021] Preferably, the screw rotation speed of the screw extruder is 150 - 200 r / min, and the length-diameter ratio is 25 - 30.

[0022] Preferably, in the wet papermaking process, the slurry concentration is controlled at 0.8 - 1.2%, and the papermaking speed is 80 - 120 m / min.

[0023] Preferably, the cell depth of the microgravure coater is 30 - 50 μm, and the line number is 200 - 300 lines / cm.

[0024] Preferably, the pressure of the hot pressing and shaping is 2 - 3 MPa, and the time is 10 - 15 s.

[0025] The present invention has the following beneficial effects:

[0026] 1. The present invention is provided with a gradient pressure-sensitive adhesive layer combined with a microcapsule phase change material, which while ensuring strong adhesion between the wing and the underwear, reduces the skin contact stickiness and reduces the risk of allergy. The chitin-modified SAP particles cooperate with the airlaid diversion layer, and the liquid diffusion speed is increased by 40%, effectively reducing side leakage.

[0027] 2. The present invention is provided with a PLA / bamboo fiber release paper: the compostable degradation time is ≤6 months, replacing the traditional PE release paper, solving the problem of white pollution, and the material recovery rate is increased to 92%; at the same time, an anti-adhesive positioning line is provided: reducing the usage amount of the release paper by 15%, and at the same time ensuring the accurate folding angle of the wing and avoiding waste of the adhesive layer.

[0028] 3. The present invention is provided with a sandwich absorbent core: a combination of a PE perforated film and a diversion non-woven fabric, the menstrual blood penetration amount is increased by 25%, and in terms of the wing size design, the fitting length after folding is 40 - 60 mm. Cooperating with the anti-adhesive positioning line, the incidence of wing displacement is reduced from 22% to 5%, improving the applicability in the sports scenario. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the structural disassembly of a double-strip wing adhesive sanitary napkin proposed by the present invention;

[0030] Figure 2 Schematic structural combination diagram of a double-strip wing glue sanitary napkin proposed by the present invention;

[0031] Figure 3 Schematic diagram of the wing structure of a double-strip wing glue sanitary napkin proposed by the present invention.

[0032] In the figure: 1. Sanitary napkin main body; 2. Wing; 3. Resin particle layer; 4. PE perforated film; 5. Flow guiding non-woven fabric; 6. Pressure-sensitive adhesive layer; 601. Outer high-viscosity area; 602. Inner low-viscosity area; 7. Absorbent core; 8. Ventilation holes; 9. Release paper. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0034] Refer to Figures 1 - 3 , a double-strip wing glue sanitary napkin, comprising:

[0035] The sanitary napkin main body 1, the sanitary napkin main body 1 has an absorbent core 7, and the absorbent core 7 is composed of an upper PE perforated film 4, a middle resin particle layer 3, and a lower flow guiding non-woven fabric 5 to form a sandwich structure, and the water absorption ratio of the resin particle layer is not less than 500%;

[0036] The pore diameter of the PE perforated film 4 is 0.1 - 0.3 mm, and the punching rate is 15 - 25%; the unit area mass of the flow guiding non-woven fabric 5 is 30 - 50 g / m 2 , the fat particle layer 3 is modified by chitin, and the particle size of the chitin-modified particles is 150 - 200 μm, and the unit area mass in the absorbent core 7 is 80 - 120 g / m 2 .

[0037] A pair of wings 2 symmetrically arranged on both sides of the sanitary napkin main body 1, the length of the wings 2 is 80 - 120 mm, the width is 20 - 30 mm, the fitting length with the sanitary napkin main body 1 after folding is 40 - 60 mm, and a double-strip pressure-sensitive adhesive layer 6 is provided at the connection between the wings 2 and the sanitary napkin main body 1. The microcapsule phase change material is uniformly dispersed in the pressure-sensitive adhesive layer 6, the particle size of the microcapsule phase change material is 10 - 30 μm, and its loading amount is 5 - 8% of the total mass of the pressure-sensitive adhesive layer 6. The pressure-sensitive adhesive layer 6 is composed of an outer high-viscosity area 601 and an inner low-viscosity area 602 to form a gradient structure, wherein the viscosity of the outer high-viscosity area 601 is greater than or equal to 3000 mPa·s, and the viscosity of the inner low-viscosity area 602 is less than or equal to 1500 mPa·s;

[0038] Release paper 9 is a base material composed of polylactic acid and bamboo fiber compounded in a mass ratio of 7:3, with a nano-SiO2 release coating applied on its surface. The solid content of the coating is 1.5-2.5%, the thickness of the release paper 9 is 35-45μm, and an anti-sticking positioning line with a width of 0.5-1.2mm is provided on the side of the release paper 9 in contact with the wing 2. The spacing between adjacent positioning lines is adapted to the folding angle of the wing of 85°-95°.

[0039] A preparation method of a double-strip wing adhesive sanitary napkin includes the following steps:

[0040] S1. Preparation of gradient pressure-sensitive adhesive: Styrene-isoprene-styrene block copolymer and tackifying resin are mixed in a mass ratio of 1:0.8-1.2, and then menthol microcapsules with a particle size of 10-30μm are added. Melting and blending are carried out at a temperature of 150-180°C by a screw extruder to prepare the gradient pressure-sensitive adhesive. The screw speed of the screw extruder is 150-200r / min, and the length-diameter ratio is 25-30.

[0041] S2. Preparation of release paper composite base material: Polylactic acid and bamboo fiber are formed into base paper by a wet papermaking process in a mass ratio of 7:3. The base paper is immersed in nano-SiO2 sol for dip coating, and then hot press forming is carried out at a temperature of 110-130°C to obtain the release paper composite base material. In the wet papermaking process, the slurry concentration is controlled at 0.8-1.2%, and the papermaking speed is 80-120m / min.

[0042] S3. Preparation of absorbent core: Using an airlaid process, chitin-modified SAP particles and a guiding non-woven fabric are compounded to obtain an absorbent core composite layer with a unit area mass of 80-120g / m 2 of the absorbent core.

[0043] S4. Coating of gradient adhesive layer: The prepared gradient pressure-sensitive adhesive is synchronously coated on both sides of the release paper using a microgravure coater, and the thickness difference of the adhesive layer is controlled within the range of ±0.01mm. The depth of the engraving cells of the microgravure coater is 30-50μm, and the line number is 200-300 lines / cm.

[0044] S5. Dynamic folding positioning: The wing is folded in half using a negative pressure conveying roller, and the folding angle of the wing is monitored in real time through a pressure sensor, and the control accuracy of the folding angle is maintained within ±0.5°. At the same time, an air flow assist nozzle with an air pressure of 0.2-0.3MPa is used to assist in aligning the wing, and the vacuum degree of the negative pressure conveying roller is maintained at -0.05 to -0.08MPa.

[0045] S6. Intelligent slitting detection: The defects of the adhesive layer are detected online through a hyperspectral imaging system, and the slitting position is dynamically adjusted by linking the servo cutter head.

[0046] S7. Product assembly: The release paper coated with an adhesive layer, the wing after folding and positioning, and the prepared absorbent core and other components are assembled to form a finished double-wing adhesive sanitary napkin. The matching error between the cutting speed of the release paper and the conveying speed of the sanitary napkin body is controlled within ≤ ±0.5 mm / s, the fitting accuracy between the cut release paper and the wing is controlled within ≤ ±0.3 mm, the pressure for thermocompression molding is 2 - 3 MPa, and the time is 10 - 15 s.

[0047] Example 1

[0048] High comfort gradient adhesive layer test

[0049] To verify the improvement effect of the synergistic effect of the gradient adhesive layer and chitin-modified SAP on comfort and leakage prevention, in this example, an experimental group, a control group 1, and a control group 2 are set up for various data test experiments, where:

[0050] The sanitary napkin of the experimental group includes those proposed in the present invention: gradient pressure-sensitive adhesive: SIS-based adhesive (outer side 3200 mPa·s) + PCM-modified adhesive (inner side 1200 mPa·s, menthol microcapsule loading 6%); absorbent core: chitin-modified SAP (particle size 180 μm, water absorption rate 500%) and 40 g / m 2 Air-laid nonwoven fabric for guiding liquid; release paper: PLA / bamboo fiber (7:3) composite substrate, nano-SiO2 coating solid content 2.0%.

[0051] The sanitary napkin of the control group 1 relatively includes: uniform pressure-sensitive adhesive (2500 mPa·s); ordinary SAP (particle size 150 μm, water absorption rate 400%); PE release paper.

[0052] The sanitary napkin of the control group 2 relatively includes: gradient pressure-sensitive adhesive (outer side 3200 mPa·s + inner side 1200 mPa·s); ordinary SAP (particle size 150 μm, water absorption rate 400%); PE release paper.

[0053] The test items include: skin allergy test, contact adhesion score, liquid diffusion test, and side leakage test. The test method is to select 50 volunteers in each group and use the sanitary napkins of each group continuously for 7 days. The skin allergy test is to record allergic reactions such as erythema and itching; the contact adhesion score test is for volunteers to subjectively score on a scale of 1 - 5; the liquid diffusion test is to use a test solution to simulate menstrual blood (pH 7.4, viscosity 3.5 mPa·s) and record the time when the diffusion diameter reaches 50 mm; the side leakage test is a 50 ml simulated menstrual blood impact (angle 45°, speed 1.2 m / s), and a side leakage volume > 0.5 ml is judged as failure. The results of each test are shown in the following table.

[0054] Table 1: Statistical data table of adhesive layer test results

[0055] Test item / group Experimental group Control group 1 Control group 2 Incidence of allergy (%) 2.5 12.0 8.5 Adhesion score (mean) 1.8 3.2 2.4 Diffusion time (seconds) 8 15 12 Leakage rate (%) 8.0 28.0 18.0

[0056] According to the above table data, it can be known that the allergy rate in the experimental group was reduced by 79% compared with that in Control Group 1 (p < 0.001), and the stickiness score was reduced by 44% (p < 0.001), indicating that the gradient adhesive layer and the PCM material significantly improved the skin contact experience. The chitin-modified SAP shortened the diffusion time by 47% (p < 0.001) and reduced the side leakage rate by 71% (p < 0.001), verifying the material synergistic effect. Therefore, the combination of the gradient adhesive layer and the chitin-modified SAP achieved a double breakthrough in comfort and leak prevention, showing a significant improvement compared with the existing technology.

[0057] Example 2

[0058] Test of Environmentally Friendly PLA Release Paper Sanitary Napkin

[0059] To verify the environmental performance and process adaptability of the environmentally friendly PLA release paper sanitary napkin, in this example, an experimental group, Control Group 1, and Control Group 2 were set up for various data test experiments, where:

[0060] The sanitary napkin in the experimental group included those proposed in the present invention: release paper: PLA / bamboo fiber (7:3), with a solid content of 1.8% of the nano-SiO2 coating; anti-sticking positioning line: width 1.0 mm, and the spacing matching the folding angle of 85° of the wing.

[0061] The sanitary napkin in Control Group 1 relatively included: PE release paper (thickness 50 μm), without a positioning line.

[0062] The sanitary napkin in Control Group 2 relatively included: PLA / bamboo fiber (5:5) release paper, with a common coating (without nano-SiO2).

[0063] The test items included: degradation test, material recovery rate, release paper consumption, and folding accuracy. 50 sanitary napkins were used for each item in each group for testing. Among them, the test method for the degradation test was to monitor the mass loss rate under composting conditions (58 °C, humidity 75%) and record the length of the degradation time; the test method for the material recovery rate was to calculate the fiber retention rate after the industrial recycling process; the release paper consumption test was to record the gram weight of the release paper used; the test method for the folding accuracy was to measure the folding angle of the wing with a laser displacement sensor. The test results are shown in the following table.

[0064] Table 2: Statistical Table of Test Results Data of Release Paper Sanitary Napkin

[0065] Test item / group Experimental group Control group 1 Control group 2 Degradation time (months) 5.5 Non - degradable 7.2 Recovery rate (%) 92 5 85 Release paper consumption (g) 0.8 1.0 0.9 Folding error (mm) ±0.2 ±0.5 ±0.3

[0066] According to the above table data, it can be known that the degradation time of the release paper in the experimental group is shortened by 24% compared with that in the control group 2 (p < 0.001), and the recovery rate is increased by 8.2% (p < 0.001), with the best environmental performance, verifying the optimality of the 7:3 ratio. And the anti-sticking positioning line reduces the consumption of the release paper by 20% (p < 0.001) and reduces the folding error by 60% (p < 0.001), improving the production efficiency and having better process adaptability. Therefore, the PLA / bamboo fiber release paper is superior to traditional materials in terms of environmental protection and process adaptability and has the feasibility of industrialization.

[0067] Example 3

[0068] Sanitary napkin production efficiency test

[0069] To verify the improvement effect of the intelligent production process on efficiency and cost, in this example, an experimental group, a control group 1 and a control group are set up for production efficiency tests, where:

[0070] The production steps of the sanitary napkins in the experimental group include those proposed in the present invention: dynamic negative pressure folding: vacuum degree -0.06 MPa, air flow assisted air pressure 0.25 MPa; hyperspectral detection: scanning speed 50 m / min; microgravure coating: cell depth 40 μm, line number 250 lines / cm.

[0071] The production steps of the sanitary napkins in the control group 1 relatively include: mechanical folding: cam mechanism (accuracy ±1°); manual inspection: sampling rate 30%; doctor blade coating: glue layer thickness difference ±0.05 mm.

[0072] The production steps of the sanitary napkins in the control group 2 relatively include: dynamic negative pressure folding: vacuum degree -0.06 MPa; manual inspection: sampling rate 30%; microgravure coating: cell depth 40 μm.

[0073] The test items include: waste product rate statistics, overall equipment efficiency, cost per pack and production speed. Among them, the test method for waste product rate statistics is to count the number of unqualified products in 100,000 continuously produced pieces; the test method for overall equipment efficiency is overall equipment efficiency = time operation rate × performance operation rate × good product rate; the test method for cost per pack is to calculate the comprehensive costs such as materials, labor, and energy consumption; the test method for production speed is to record the maximum stable speed (pieces / minute) during continuous production. The test results of each item are shown in the following table.

[0074] Table 3: Statistical table of sanitary napkin production efficiency test results data

[0075] Test item / group Experimental group Control group 1 Control group 2 Scrap rate (%) 0.08 0.8 0.2 Overall equipment effectiveness (%) 96 75 88 Cost per pack (yuan) 0.92 1.05 0.98 Production speed (pieces / minute) 1200 800 1000

[0076] According to the above table data, it can be known that intelligent detection reduces the scrap rate by 90% (p < 0.001), improves OEE by 28% (p < 0.001), increases the production speed by 50% (p < 0.001), and reduces the glue consumption of gravure coating by 20%, and the cost per package is reduced by 12.4% (p < 0.001). Therefore, the intelligent production process proposed by the present invention significantly improves production efficiency and reduces costs, verifying the economic advantages of the invention.

[0077] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A sanitary napkin with double wing adhesive, characterized in that: include: A sanitary napkin body (1), the sanitary napkin body (1) having an absorbent core (7), the absorbent core (7) consisting of an upper layer of a PE perforated film (4), a middle layer of a resin particle layer (3), and a lower layer of a flow-guiding non-woven fabric (5), forming a sandwich structure, and the water absorption rate of the resin particle layer (3) is not less than 500%; A pair of wings (2) symmetrically arranged on both sides of the sanitary napkin body (1), wherein the connection between the wings (2) and the sanitary napkin body (1) is provided with two pressure-sensitive adhesive layers (6), wherein the pressure-sensitive adhesive layer (6) is composed of an outer high-viscosity region (601) and an inner low-viscosity region (602) forming a gradient structure, wherein the viscosity of the outer high-viscosity region (601) is greater than or equal to 3000 mPa·s, and the viscosity of the inner low-viscosity region (602) is less than or equal to 1500 mPa·s; The release paper (9) is a substrate formed by a composite of polylactic acid and bamboo fiber in a mass ratio of 7:3, the surface of which is coated with a nano-SiO2 release coating, the solid content of the coating being 1.5-2.5%, the thickness of the release paper (9) being 35-45 μm, and an anti-sticking positioning line with a width of 0.5-1.2 mm is provided on the contact side of the release paper (9) with the wing (2), and the spacing between adjacent positioning lines is adapted to the folding angle of the wing (2) of 85°-95°.

2. A double-wing adhesive sanitary napkin according to claim 1, characterized in that: Microcapsule phase change material is evenly dispersed in the pressure-sensitive adhesive layer (6); the particle size of the microcapsule phase change material is 10-30 μm, and the loading amount thereof is 5-8% of the total mass of the pressure-sensitive adhesive layer (6).

3. A double-wing adhesive sanitary napkin according to claim 1, characterized in that: The PE perforated film (4) has a pore size of 0.1-0.3 mm and a perforation rate of 15-25%; the flow-guiding non-woven fabric (5) has a mass per unit area of ​​30-50 g / m².

4. A double-wing adhesive sanitary napkin according to claim 1, characterized in that: The lipid particle layer (3) is modified with chitosan, and the particle size of the modified chitosan particles is 150-200 μm, and the mass per unit area in the absorbent core (7) is 80-120 g / m².

5. A double-wing adhesive sanitary napkin according to claim 1, characterized in that: The wing (2) has a length of 80-120 mm and a width of 20-30 mm, and after being folded, the length of the wing (2) attached to the sanitary napkin body (1) is 40-60 mm.

6. A method for preparing a double-wing adhesive sanitary napkin according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, preparing a gradient pressure-sensitive adhesive, mixing a styrene-isoprene-styrene block copolymer and a tackifying resin in a mass ratio of 1:0.8-1.2, then adding menthol microcapsules with a particle size of 10-30 μm, and melt-blending them at a temperature of 150-180° C. through a screw extruder to prepare a gradient pressure-sensitive adhesive; S2, preparation of a release paper composite substrate, polylactic acid and bamboo fiber in a mass ratio of 7:3 through a wet papermaking process to form a base paper, immersing the base paper in a nano-SiO2 sol for dip coating, and then hot pressing and shaping at a temperature of 110-130° C. to obtain a release paper composite substrate; S3, preparing the absorbent core, using an air-laid process to compound the chitosan-modified SAP particles with the flow-guiding non-woven fabric to obtain an absorbent core composite layer with a unit area mass of 80-120 g / m²; S4, gradient adhesive layer coating, using a micro-gravure coater to simultaneously coat the gradient pressure-sensitive adhesive prepared above on both sides of the release paper, and controlling the thickness difference of the adhesive layer within the range of ±0.01 mm; S5, dynamic folding positioning, using negative pressure conveying rollers to fold the wings, using pressure sensors to monitor the folding angle of the wings in real time, maintaining the folding angle control accuracy at ±0.5°, and using airflow auxiliary nozzles with an air pressure of 0.2-0.3MPa to assist in aligning the wings, and the vacuum degree of the negative pressure conveying rollers is maintained at -0.05 to -0.08MPa; S6, intelligent slitting detection, using the hyperspectral imaging system to detect adhesive layer defects online, and linking the servo cutter head to dynamically adjust the slitting position; S7. Product assembly: Assemble the release paper coated with the adhesive layer, the folded and positioned wings, and the prepared absorbent core and other components to form a finished double-wing adhesive sanitary napkin. The matching error between the slitting speed of the release paper and the conveying speed of the sanitary napkin body is controlled to be ≤±0.5mm / s, and the fitting accuracy between the release paper and the wings after slitting is controlled to be ≤±0.3mm.

7. The method for preparing a double-wing adhesive sanitary napkin according to claim 6, characterized in that: The screw extruder has a screw speed of 150-200 r / min and an aspect ratio of 25-30.

8. The method for preparing a double-wing adhesive sanitary napkin according to claim 6, characterized in that: In the wet papermaking process, the slurry concentration is controlled at 0.8-1.2%, and the papermaking speed is 80-120 m / min.

9. The method for preparing a double-wing adhesive sanitary napkin according to claim 6, characterized in that: The cell depth of the micro-gravure coater is 30-50 μm, and the line count is 200-300 lines / cm.

10. The method for preparing a double-wing adhesive sanitary napkin according to claim 6, characterized in that: The pressure of the hot pressing is 2-3 MPa, and the time is 10-15 s.

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