Multifunctional comfortable breathable absorption core, preparation method and disposable hygienic product

Abstract

The invention discloses a multifunctional comfortable breathable absorption core, a preparation method and a disposable hygienic product. Comprising the following steps: preparing a nanofiber directional lyophilic contact layer positioned on an upper layer, preparing a micron dynamic respiratory regulation diffusion layer positioned on a middle layer and preparing a millimeter liquid storage absorption layer positioned on a lower layer so as to construct a nano-micron-millimeter composite pore system. The upper layer is a nanofiber directional lyophilic contact layer, the middle layer is a micron dynamic breathing regulation diffusion layer, the lower layer is a millimeter liquid storage absorption layer, a nano-micron-millimeter composite pore system is constructed, pores with specific sizes are manufactured in a layering mode, interlayer capillary pressure difference is used as core driving force, upper-layer ultrafast absorption is achieved, and the absorption efficiency is improved. And the middle layer rapidly and transversely diffuses, and the lower layer stores and locks liquid in an ultra-large capacity, and effectively prevents reverse osmosis.

Description

Technical Field

[0001] This invention relates to a multifunctional, comfortable, breathable, and absorbent core, its preparation method, and disposable hygiene products. Background Technology

[0002] As people's demands for quality of life continue to rise, the needs for hygiene products are no longer limited to basic absorbency. However, existing absorbent cores have certain limitations in terms of function and performance. Taking the absorbent layer of diapers and sanitary napkins as an example, they are mainly made of traditional cotton materials or superabsorbent polymer (SAP) blends. Although these materials have a certain absorbency, after prolonged use, the moisture cannot evaporate quickly, easily leading to localized dampness and stuffiness, which can cause skin discomfort and even allergies. In addition, the structure of traditional absorbent cores is relatively simple, lacking good breathability and softness, which to some extent affects the user's comfort experience. Summary of the Invention

[0003] To overcome the above-mentioned defects, the purpose of this invention is to provide a multifunctional, comfortable, breathable, and absorbent core and its preparation method.

[0004] To achieve the above objectives, the method for preparing the multifunctional comfortable breathable absorbent core of the present invention includes: preparing a nanofiber oriented hydrophilic contact layer in the upper layer, preparing a micron dynamic respiratory regulation diffusion layer in the middle layer, and preparing a millimeter liquid storage and absorption layer in the lower layer, so as to construct a nano-micron-millimeter composite pore system.

[0005] Furthermore, the preparation steps of the nanofiber oriented hydrophilic contact layer include: Mix polylactic acid with chitosan; Electrospinning is employed, using a rotating cylinder as the receiving device. The movement of the rotating cylinder causes the fibers to align under the action of an electric field. The fiber diameter is controlled at 100-300nm, the pore size at 50-250nm, the porosity at 70-85%, and the fiber orientation at >80%, thus constructing a nanoporous structure and forming a fiber nonwoven fabric with specific orientation.

[0006] Furthermore, it also includes using laser micro-etching modification technology to perform localized permanent hydrophilic modification on the surface of the hydrophilic contact layer.

[0007] Furthermore, the middle dynamic breathing regulation diffusion layer is reinforced by a layered composite process using two layers of nonwoven fabric; among which, The upper nonwoven fabric is composed of 1.5~3.0D wood pulp fibers and 1.2~2.2D ES fibers. It is reinforced by hot air to form a loose 3D honeycomb channel structure with a pore size of 5-20μm. The channel density is 200-400 honeycomb units per square centimeter, and the porosity is 90-95%. This effectively receives the liquid from the upper layer. After the liquid seeps down, the honeycomb structure provides multi-directional liquid channels, which allow it to spread rapidly in the planar direction (lateral flow guidance) and avoid concentrated seepage of liquid. The lower layer consists of fine denier fibers of 0.8~1.0D calcium alginate fiber and 0.8~1.2D polyester fiber. Using the upper hot-air nonwoven fabric as the base, a double-layer nonwoven fabric is prepared by layering calcium alginate fiber and polyester fiber through a layered composite process. High-pressure hydroentangling is used to interweave the fibers, changing the spiral angle between the fiber layers to construct a reversible deformation structure with a spiral width of 50-100μm and a spacing of 10-50μm for micron-sized air passages. This forms a spiral air passage with an embedded micro-spring structure, which enhances gas diffusion efficiency and forms a dynamically breathing-regulated micron-sized diffusion layer.

[0008] Furthermore, the lower millimeter-level intelligent liquid storage support layer comprises an upper layer dominated by poly(N-isopropylacrylamide) (PNIPAM) and a lower layer dominated by carboxymethyl cellulose (CMC); PNIPAM and CMC are physically or chemically cross-linked to construct an interpenetrating network structure, forming an intelligent liquid storage absorption layer with dual environmental response capabilities.

[0009] Furthermore, the absorbent layer is provided with transverse and longitudinal V-shaped gradient grooves, which are shallower at the front end, with a width of 1-3 mm, a depth of 0.5-1 mm, and a spacing of 5-8 mm; it adopts a large millimeter-sized pore / cavity to provide a huge space to accommodate the absorbed liquid, and the front and rear V-shaped double grooves prevent leakage. It allows for rapid drainage through transverse and longitudinal channels and allows the liquid to flow and redistribute relatively freely, providing support for the upper layer.

[0010] Furthermore, the upper nanofiber oriented hydrophilic contact layer, the middle dynamic breathability regulating micron diffusion layer, and the lower millimeter intelligent liquid storage and absorption layer are composited layer by layer by multi-stage ultrasonic welding, and the welding area ratio is controlled to be ≤15% to obtain a multifunctional, comfortable, breathable composite absorption core.

[0011] To achieve the above objectives, the multifunctional comfortable breathable absorbent core of the present invention includes: a nanofiber directional hydrophilic contact layer in the upper layer, a micron dynamic breathability regulating diffusion layer in the middle layer, and a millimeter liquid storage and absorption layer in the lower layer.

[0012] To achieve the above objectives, the present invention provides a disposable hygiene product comprising a surface layer made of insulating and soothing nonwoven fabric and a core layer made of the aforementioned gradient-distributed absorbent core.

[0013] This invention employs a nanofiber-oriented hydrophilic contact layer as the upper layer, a micron-level dynamic breathing-regulated diffusion layer as the middle layer, and a millimeter-level liquid storage and absorption layer as the lower layer, constructing a nano-micron-millimeter composite pore system. By creating pores of specific scales layer by layer and utilizing the interlayer capillary pressure difference as the core driving force, it achieves ultra-fast absorption in the upper layer, rapid lateral diffusion in the middle layer, and ultra-large capacity storage and liquid locking in the lower layer, effectively preventing backflow. Through cross-scale topological interlocking design and dynamic response control, a smart liquid transport network with hierarchical self-adaptive capabilities is constructed. The upper nanofiber-oriented hydrophilic contact layer uses laser micro-etching to pattern a labyrinthine folded microsphere structure resembling a dahlia leaf and hydrophilic channels resembling tree roots, which can instantly "draw" the contacting liquid into the core, greatly reducing the liquid's residence time on the surface. The middle micron layer uses a 3D honeycomb structure and interlayer spiral micron-level ventilation channels to provide excellent in-planar liquid transport channels, which can rapidly diffuse the locally absorbed liquid in the upper layer to the surrounding areas, making full use of the entire core's absorption area and preventing localized backflow. Leakage caused by excessively rapid saturation is prevented; the bottom millimeter-level liquid storage layer is designed with horizontal and vertical V-shaped gradient grooves to achieve gradient interlocking of nano-micro-millimeter pores; in the dry state, the nanofiber network and honeycomb channels form a continuous air-permeable path, while in the wet state, the honeycomb channels and V-shaped grooves form an anti-expansion air layer to suppress the "suffocation effect" and form a dual-mode air permeability-flow guidance switching; combined with the close coupling of the gelation characteristics of micron-level seaweed fibers and the elastic deformation pressure feedback of the micro-spring structure, and the phase change regulation of the millimeter-level temperature-sensitive material (PNIPAM / CMC), a highly efficient, comfortable, and reliable liquid management "system" is formed. Detailed Implementation

[0014] The present invention will now be described in detail with reference to the embodiments.

[0015] The present invention discloses a multifunctional comfortable and breathable absorbent core, which is a composite absorbent core prepared by a multi-scale gradient structure design of upper, middle and lower layers. The upper layer is a nanofiber directional hydrophilic contact layer, the middle layer is a micron dynamic breathable diffusion layer, and the lower layer is a millimeter liquid storage and absorption layer, thus constructing a nano-micron-millimeter composite pore system to achieve rapid liquid infiltration, lateral diffusion and storage isolation, and solve the problems of back osmosis and stuffiness of traditional cores.

[0016] The above-mentioned method for preparing the absorber core includes the following steps: I. Preparation of the upper nanofiber oriented hydrophilic contact layer The upper oriented hydrophilic contact layer of nanofibers is composed of polylactic acid and chitosan. Using biomimetic topology processing technology, the mixed solution of polylactic acid and chitosan is oriented through electrospinning to form a nonwoven fabric with specific orientation. The surface layer is modified by laser micro-etching to construct a microstructure, forming a selective liquid-guided superhydrophilic surface, realizing dynamic wettability control. Through small-scale nanoscale pores, extremely strong capillary forces are generated, which can instantly "grab" liquid.

[0017] Both polylactic acid (PLA) and chitosan are biodegradable materials. Their nonwoven fabric products can naturally degrade after use, causing no environmental pollution. They have high biocompatibility and are non-cytotoxic. Chitosan also possesses excellent antibacterial properties, which can endow materials with antibacterial functions.

[0018] Polylactic acid (PLA) and chitosan are mixed, with chitosan weighing 5-20 parts and the PLA ratio being 1-10:1. Electrospinning is employed using a rotating cylinder as the receiving device at a distance of 15cm. The rotation of the cylinder causes the fibers to orient themselves under the influence of an electric field. The fiber diameter is controlled at 100-300nm, the pore size at 50-250nm, the porosity at 70-85%, and the fiber orientation at >80%, constructing a nanoporous structure to form a nonwoven fabric with specific orientation. Utilizing the unique wicking effect of PLA, moisture is wicked away and dried quickly through capillary action, allowing liquids to instantly penetrate the surface and providing a dry and comfortable user experience. Simultaneously, the cationic properties of chitosan adsorb Cl⁻, PO₄³⁻, SO₄²⁻, and negatively charged proteins in urine, reducing liquid rebound.

[0019] The surface of the hydrophilic contact layer is treated with laser micro-etching modification technology (which uses physical laser micro-etching to locally modify the surface without damaging the overall structure of the nonwoven fabric, and the transition between the modified and unmodified areas is natural, achieving permanent hydrophilicity. Compared with chemical modification, it is less likely to fall off and cause blockage of the hydrophilic layer pores). A patterned distribution of maze-shaped wrinkled microspheres with a dahlia leaf structure (controlling the size of the wrinkled microspheres to 1-10um) and hydrophilic channels with a tree root structure (contact angle controlled at <10°, hydrophilic channel width at 100-350um) is constructed to control the liquid flow path and achieve selective liquid guidance, superhydrophilicity and dynamic wettability regulation on the surface. The liquid first contacts the surface microspheres, utilizing the maze-like three-dimensional structure and interlaced channels formed on the surface of the wrinkled microspheres to create a multi-level porous structure. This enhances the surface hydration layer and steric hindrance effect, reducing the adhesion of highly viscous pollutants while allowing the liquid to pass through rapidly. A continuous hydration layer is formed on the surface, and the liquid binds to the microsphere surface through hydrogen bonding, reducing flow resistance. At the same time, the capillary effect is enhanced by the root-like hydrophilic channels, driving the liquid to pass through the porous structure rapidly, achieving rapid liquid penetration, controlling the wettability of the nonwoven fabric surface and air convection, improving the overall breathability, and maintaining dryness.

[0020] II. Preparation of the Middle Layer Dynamic Respiratory Regulation Diffusion Layer The middle dynamic breathing regulation diffusion layer is made of double-layer nonwoven fabric reinforced by a layered composite process.

[0021] The upper nonwoven fabric is made of 1.5~3.0D wood pulp fiber and 1.2~2.2D ES fiber, which are air-blown into a web in a 7:3 ratio. It is then reinforced by hot air (160℃) to form a 3D honeycomb micron-level channel (pore size 5-20μm) fluffy structure. The channel density is 200-400 honeycomb units per square centimeter, with a porosity of 90-95% and a moderate pore size. This structure can effectively receive liquid from the upper layer. After the liquid seeps down, the honeycomb structure provides multi-directional liquid channels, allowing it to spread rapidly in the planar direction (lateral flow guidance) and preventing concentrated seepage.

[0022] The lower layer consists of fine denier fibers of 0.8~1.0D calcium alginate fiber and 0.8~1.2D polyester fiber. Using the upper hot-air nonwoven fabric as the base, a double-layer nonwoven fabric is prepared by layering calcium alginate fiber and polyester fiber through a layered composite process. High-pressure hydroentangling is used to interweave the fibers, changing the spiral angle between the fiber layers to construct a spiral micron-shaped air passage with a reversible deformation structure (width 50-100μm, spacing 10-50μm). A micro-spring structure is embedded in the spiral air passage to enhance gas diffusion efficiency and form a dynamic breathing-regulating micron-diffusion layer.

[0023] In the dry state, the surface nanofiber pores and the middle honeycomb channels form a continuous breathable network to maintain open airflow and maintain breathability. In the wet state, after liquid infiltration, the hot air 3D honeycomb structure and the interlayer spiral micron-shaped air channels provide multi-directional micron-level flow diffusion channels, reducing the flow resistance of liquid infiltration and promoting rapid lateral diffusion of liquid. The calcium alginate layer of the lower fine denier fibers receives the diffused liquid, absorbs moisture quickly, and expands upon contact with water, compressing the cross-sectional area of ​​the air channels to 30% of the initial size, reducing the channels and preventing liquid backflow. When the liquid is absorbed, the external force releases the spring rebound, causing the air channels to return to their original shape, achieving dynamic adjustment of breathability. At the same time, the lower layer adds menthol microcapsules that release upon contact with water, achieving a cooling sensation and improving overall breathability and comfort.

[0024] III. Preparation of the lower millimeter-level intelligent liquid storage support layer The lower millimeter-level intelligent liquid storage support layer is composed of poly(N-isopropylacrylamide) (PNIPAM) and carboxymethyl cellulose (CMC).

[0025] PNIPAM and CMC are cross-linked physically or chemically to construct an interpenetrating network structure, forming a smart liquid storage and absorption layer with dual environmental response capabilities, enabling on-demand absorption and controlled release of liquid. The upper layer, dominated by PNIPAM, responds primarily to temperature changes; when the liquid temperature is triggered (>33℃), the hydrogel pores shrink, accelerating liquid infiltration. The lower layer, dominated by CMC, responds rapidly to pH changes; when the liquid pH rises (>7), the carboxylic acid groups in the cellulose fibers ionize, causing the molecular chains to extend and swell, enhancing absorbency. At normal temperature and pH, PNIPAM absorbs excess moisture, preventing backflow and maintaining dryness. The absorption layer features transverse and longitudinal V-shaped gradient grooves, shallower at the front (1-3mm wide, 0.5-1mm deep, 5-8mm spacing); large millimeter pores / cavities provide ample space to accommodate the absorbed liquid, while the front and rear V-shaped double grooves prevent leakage, allowing for rapid drainage through transverse and longitudinal channels and permitting relatively free flow and redistribution of the liquid, providing support for the upper layer. Meanwhile, when the composite core is wet, the bottom air channel maintains the air passage and the middle layer to form a dual air passage, avoiding the "suffocation effect" caused by the expansion of SAP in traditional cores.

[0026] IV. Composite The upper layer of oriented nanofibers, the middle layer of dynamic respiratory regulation micron diffusion layer, and the lower layer of millimeter-sized intelligent liquid storage and absorption layer are composited layer by layer using multi-stage ultrasonic welding (frequency 35kHz, pressure 0.3MPa), with the welding area ratio controlled to ≤15%, to obtain a multifunctional, comfortable, breathable composite absorption core.

[0027] In summary, this invention employs a nanofiber-oriented hydrophilic contact layer as the upper layer, a micron-level dynamic breathing-regulated diffusion layer as the middle layer, and a millimeter-level liquid storage and absorption layer as the lower layer, constructing a nano-micron-millimeter composite pore system. By creating pores of specific scales layer by layer and utilizing the interlayer capillary pressure difference as the core driving force, it achieves ultra-fast absorption in the upper layer, rapid lateral diffusion in the middle layer, and ultra-large capacity storage and liquid locking in the lower layer, effectively preventing backflow. Through cross-scale topological interlocking design and dynamic response regulation, a smart liquid transport network with hierarchical self-adaptive capabilities is constructed. The upper nanofiber-oriented hydrophilic contact layer uses laser micro-etching to pattern a labyrinthine folded microsphere structure resembling a dahlia leaf and hydrophilic channels resembling tree roots, which can instantly "draw" the contacting liquid into the core, greatly reducing the liquid's residence time on the surface. The middle micron layer uses a 3D honeycomb structure and interlayer spiral micron-level ventilation channels to provide excellent in-planar liquid transport channels, which can rapidly diffuse the locally absorbed liquid in the upper layer to the surrounding areas, making full use of the entire core's absorption area and preventing localized backflow. Leakage caused by excessively rapid saturation is prevented; the bottom millimeter-level liquid storage layer is designed with horizontal and vertical V-shaped gradient grooves to achieve gradient interlocking of nano-micro-millimeter pores; in the dry state, the nanofiber network and honeycomb channels form a continuous air-permeable path, while in the wet state, the honeycomb channels and V-shaped grooves form an anti-expansion air layer to suppress the "suffocation effect" and form a dual-mode air permeability-flow guidance switching; combined with the close coupling of the gelation characteristics of micron-level seaweed fibers and the elastic deformation pressure feedback of the micro-spring structure, and the phase change regulation of the millimeter-level temperature-sensitive material (PNIPAM / CMC), a highly efficient, comfortable, and reliable liquid management "system" is formed.

[0028] According to QB / T 5650-2021 Composite absorbent core for disposable paper sanitary products, after completing the rewetting test, the ratio of the longest liquid diffusion length to the total length is measured to test the absorbent core, so as to characterize its absorption time, rewetting amount, and diffusion length.

[0029] As shown in the table above, the upper layer of this invention uses nanofibers arranged in a directional manner and a patterned distribution constructed using biomimetic topological structure processing technology. This allows it to instantly "draw" the liquid into the core, greatly reducing the liquid's residence time on the surface. The middle layer uses a 3D honeycomb structure and interlayer spiral micron-shaped ventilation channels to rapidly diffuse the locally absorbed liquid from the upper layer to the surrounding areas, making full use of the entire core's absorption area and preventing leakage caused by excessively rapid local saturation. The bottom layer uses PNIPAM and CMC to construct an interpenetrating network structure and designs transverse and longitudinal V-shaped gradient grooves to form an intelligent liquid storage and absorption layer with dual environmental response capabilities, achieving liquid absorption and preventing backflow, while maintaining dryness.

[0030] The air permeability of the absorbent core was tested in accordance with GB / T 5453-2025 Textiles - Determination of air permeability of fabrics, in order to characterize its air permeability.

[0031] As can be seen from the table above, in the dry state, the upper pores, the middle honeycomb structure, and the interlayer spiral air channels form a continuous breathable network to maintain open airflow and maintain the air permeability. In the wet state, the bottom guide groove maintains the air channel and the middle layer to form a dual air passage, avoiding the "suffocation effect" caused by the expansion of SAP in traditional cores. Example

[0032] A hygiene product according to this embodiment includes a surface layer made of insulating and soothing nonwoven fabric and a multifunctional comfortable, breathable, and absorbent core layer prepared according to the above method.

[0033] The preparation method of the insulating and soothing nonwoven fabric includes the following steps: 1) Pre-treatment of ES fiber web surface to form a positively charged nanoscale mesh pre-coating on the fiber surface: ES fiber is treated in an alkaline solution at 55°C for 15 minutes to etch the fiber surface to form a microgroove structure. Then, natural cationic polysaccharides are adsorbed on the fiber surface by padding to form a positively charged nanoscale mesh pre-coating, which enhances the adhesion of subsequent materials. Natural cationic polysaccharides are also used to electrostatically destroy the cell membrane of microorganisms to increase biocompatibility.

[0034] 2) Construct a dynamic slow-release composite mineralization layer outside the nanoscale mesh pre-coating: Prepare a solution containing zinc gluconate, immerse the pretreated ES fibers in it, and induce the growth of hydroxyapatite (HA) nanocrystals by ultrasound at 40°C and pH 8.2. Soothing ingredients (panthenol, dipotassium glycyrrhizate, ceramide NP, and purslane extract) are simultaneously embedded in the HA lattice. During the mineralization process, zinc gluconate and soothing ingredients form coordination bonds with HA, achieving the slow release of zinc ions and exerting anti-inflammatory and soothing effects.

[0035] 3) Constructing a gradient pore structure on the fiber mesh of the mineralized layer, including: The fiber web loaded with mineralized layer is subjected to bidirectional gradient stretching. The upper layer stretching ratio is controlled at 1.8:1 to form a fine structure with a pore size of 5-10μm, which prevents liquid backflow. The lower layer (contact absorption core) stretching ratio is increased to 2.5:1 to form a loose structure with a pore size of 15-20μm, which accelerates liquid infiltration. Meanwhile, during the hot pressing and setting stage (temperature 125℃, pressure 0.8MPa), the low melting point of ES fiber is utilized to partially melt the fiber intersections, constructing a stable three-dimensional porous skeleton, and increasing the air permeability to 4500-6000mm / s.

[0036] 4) Preparation of self-crosslinking adhesive interfaces: A two-component adhesive layer composed of methacrylamide gelatin (GelMA) and sodium alginate is coated on the bottom surface of the nonwoven fabric surface. A trace amount of CaCO3 (0.1%-1%) is added to the core encapsulation layer. When in contact with liquid, the hydroxyl and amino groups of methacrylamide gelatin (GelMA) can form hydrogen bonds with the carboxyl groups of sodium alginate, enhancing compatibility with sodium alginate. Simultaneously, the ionic cross-linking network of sodium alginate and calcium ions is embedded in the network structure of GelMA, forming a triple effect of "hydrogen bond assistance + physical entanglement + chemical cross-linking," achieving a peel strength of 10-25 N / 25 mm, effectively preventing surface layer displacement during use. This design directly relies on the gradient pore structure of the third step. The fine pores in the upper layer control the liquid contact rate, allowing the cross-linking reaction to proceed gently and avoiding excessive cross-linking that leads to brittleness. The loose pores in the lower layer quickly guide the liquid to the core, ensuring continuous release of Ca²⁺ to maintain adhesive strength, forming a closed-loop support of "structure-function-stability."

[0037] Experimental example: Materials preparation: Substrate: ES fiber (20g / m²) Reagents: 0.5% NaOH solution, chitosan quaternary ammonium salt (molecular weight 50 kDa), zinc gluconate (purity 99%), hydroxyapatite precursor (Ca / P = 1.67), panthenol (purity 98%), dipotassium glycyrrhizate (purity 95%), ceramide NP (purity 90%), purslane extract (concentration 10%), methacrylamide gelatin (GelMA, degree of substitution 70%), sodium alginate (low viscosity), CaCO3 powder (particle size 5 μm). Implementation steps: 1. ES fiber surface pretreatment: ES fiber mesh was immersed in a 0.5% NaOH solution at 55℃ and magnetically stirred for 15 minutes. It was then removed and rinsed with deionized water until neutral. The fiber mesh was then immersed in a 2% chitosan quaternary ammonium salt solution (pH 6.5) using a pad-dip method (80% roll-off). After air-drying at room temperature, a positively charged nano-mesh pre-coating was formed. The zeta potential of the fiber surface was measured to be +35mV, and the groove depth was approximately 200nm.

[0038] 2. Construction of a dynamically released composite mineralization layer: A mixture containing 0.1 mol / L zinc gluconate, 0.05% panthenol, 0.03% dipotassium glycyrrhizate, 0.02% ceramide NP, and 0.1% purslane extract was prepared, and the pH was adjusted to 8.2. The pretreated ES fiber mesh was immersed in the mixture and reacted in an ultrasonic cleaner (40 kHz, 100 W) at 40℃ for 30 minutes to induce HA nanocrystal growth. After the reaction, the fiber mesh was removed and vacuum dried at 60℃. The mineralized layer thickness was measured to be 150 nm, and the HA crystallinity was 75%. 3. Gradient pore structure formation: The fiber web with the mineralized layer was fixed to a biaxial stretching device. The upper layer (skin contact surface) was stretched laterally at a stretch ratio of 1.8:1, and the lower layer (core contact surface) was stretched longitudinally at a stretch ratio of 2.5:1, maintaining a tension of 30N. It was then transferred to a hot press setting machine and processed at 125℃ and 0.8MPa for 10 seconds. After cooling, the pore size of the upper layer was measured to be 7μm and the pore size of the lower layer was 18μm. 4. Self-crosslinking adhesive interface design: A GelMA / sodium alginate mixture (mass ratio 3:1, solid content 15%) was coated on the reverse side of the fiber mesh layer (skin contact surface), with a coating thickness of 20 μm. The core wrapping layer was uniformly sprayed with a 0.5% CaCO3 suspension (solvent: 50% ethanol), dried at room temperature, and then assembled.

[0039] The material performance test results for the experimental example are as follows:

[0040] In this embodiment, disposable hygiene products such as sanitary napkins and diapers are designed with an insulating and soothing surface layer. Using ES fiber as the base material, a dynamic slow-release composite system is employed to embed anti-inflammatory factors into a biomimetic mineralization layer, achieving continuous release of ingredients. A gradient pore breathable structure is constructed, with a denser pore size distribution at the top and a looser one at the bottom achieved through bidirectional stretching, ensuring rapid liquid penetration while maintaining good breathability. A self-crosslinking adhesive interface is developed, allowing the surface layer and absorbent core to chemically bond upon contact with liquid, achieving the insulating and soothing effect. The composite core structure, combining the aforementioned foaming material with a rapidly absorbing liquid storage layer, constructs a highly synergistic liquid management system. The gradient design between layers ensures smooth liquid transfer and progressively enhances absorbency. Each layer is interlocked, with mutual structural strength support, resulting in a soft and thin overall core.

[0041] The present invention has been described in detail above, but it is not limited to the embodiments described above. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the invention. Many other changes and modifications made without departing from the concept and scope of the invention should be considered within the scope of protection of the present invention.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing a multi-functional comfortable air-permeable absorbent core, characterized by, The method comprises: preparing a nanofiber directional lyophilic contact layer on an upper layer, preparing a micrometer dynamic respiration regulating diffusion layer on a middle layer, and preparing a millimeter liquid storage absorption layer on a lower layer to construct a nanometer-micrometer-millimeter composite pore system.

2. The method for preparing the multifunctional comfortable breathable and absorbent core as described in claim 1, characterized in that, The preparation step of the nanofiber directional lyophilic contact layer comprises: mixing polylactic acid and chitosan; an electrospinning process is adopted, a rotating cylinder is used as a receiving device, fibers are arranged directionally under the action of an electric field force through the movement of the rotating cylinder, the fiber diameter is controlled to be 100-300 nm, the pore diameter is controlled to be 50-250 nm, the porosity is 70-85%, and the fiber orientation degree is greater than 80%, a nanometer porous structure is constructed, and a fiber non-woven fabric with specific directionality is formed.

3. The method for preparing the multifunctional comfortable breathable and absorbent core as described in claim 1, characterized in that, The method further comprises performing local area permanent hydrophilic modification on a surface layer of the lyophilic contact layer by using a laser micro-etching modification technology.

4. The method for preparing the multifunctional comfortable breathable and absorbent core as described in claim 1, characterized in that, The middle layer dynamic respiration regulating diffusion layer is formed by reinforcing a double-layer non-woven fabric through a layering and compounding process; wherein, the upper layer non-woven fabric is composed of 1.5-3.0D wood pulp fibers and 1.2-2.2D ES fibers, is formed into a micrometer 3D honeycomb channel fluffy structure with a pore diameter of 5-20 μm through hot air reinforcement, has a channel density of 200-400 honeycomb units per square centimeter, and has a porosity of 90-95%, so as to effectively receive the liquid transmitted from the upper layer, provide multi-directional liquid channels through the honeycomb structure after the liquid infiltrates, and enable the liquid to quickly diffuse in the plane direction (lateral flow guide), thereby avoiding concentrated liquid infiltration; the lower layer is composed of 0.8-1.0D calcium alginate fibers and 0.8-1.2D fine polyester fibers, the calcium alginate fibers and the polyester fibers are prepared into a double-layer non-woven fabric through a layering and compounding process with the upper layer hot air non-woven fabric as a substrate, the fibers are interwoven through high-pressure water jetting, the spiral angle between the fiber layers is changed, a reversible deformation structure is constructed, a micrometer air passage with a spiral width of 50-100 μm and a spacing of 10-50 μm is formed, and thus a spiral air passage embedded with a micro-spring structure is formed, the gas diffusion efficiency is enhanced, and a dynamic respiration regulating micrometer diffusion layer is formed.

5. The method for preparing the multifunctional comfortable breathable and absorbent core as described in claim 1, characterized in that, The lower layer millimeter intelligent liquid storage support layer comprises an upper layer dominated by poly-N-isopropyl acrylamide (PNIPAM) and a lower layer dominated by carboxymethyl cellulose (CMC); the PNIPAM and the CMC are constructed into an interpenetrating network structure through physical or chemical crosslinking, and an intelligent liquid storage absorption layer with double environmental response capabilities is formed.

6. The method for preparing the multifunctional comfortable breathable and absorbent core as described in claim 5, characterized in that, The absorption layer is provided with transverse and longitudinal V-shaped gradient grooves, the front end is shallow, the width is 1-3 mm, the depth is 0.5-1 mm, and the spacing is 5-8 mm; a millimeter large pore diameter / cavity is adopted to provide a large space for accommodating the absorbed liquid, the front and rear V-shaped double grooves prevent liquid leakage, quickly drain through the transverse and longitudinal passages, and allow the liquid to flow and redistribute relatively freely, thereby providing support for the upper layer.

7. The method for preparing the multifunctional comfortable breathable and absorbent core as described in claim 5, characterized in that, The upper layer nanofiber directional lyophilic contact layer, the middle layer dynamic respiration regulating micrometer diffusion layer, and the lower layer millimeter intelligent liquid storage absorption layer are compounded layer by layer through multi-stage ultrasonic welding, and the welding area ratio is controlled to be less than or equal to 15% to obtain a multifunctional comfortable and breathable composite absorption core.

8. A multi-functional comfort air-through absorbent core, characterized by, The core comprises: a nanofiber directional lyophilic contact layer on the upper layer, a micrometer dynamic respiration regulating diffusion layer on the middle layer, and a millimeter liquid storage absorption layer on the lower layer.

9. A disposable hygienic article characterized in that, The sanitary product comprises a surface layer prepared from an isolation and soothing non-woven fabric and a core layer prepared from the gradient distribution absorption core according to any one of claims 1-9.

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