Full-hydrophilic real-fan-tail-shaped sanitary towel with vertically-extending core body and preparation method of full-hydrophilic real-fan-tail-shaped sanitary towel

Abstract

The invention discloses a full-hydrophilic real-fan-tail-shaped sanitary napkin with a vertically-extending core and a preparation method thereof, and relates to the technical field of hygienic products, the sanitary napkin sequentially comprises a hydrophilic surface layer, a flow guide layer, the core and a bottom layer from top to bottom, the core extends to the end in the length direction of the sanitary napkin and is integrally formed with the end, and the bottom layer is arranged at the bottom of the sanitary napkin. One end part is in a real fan-tail shape; the core body comprises an upper layer, a middle layer and a lower layer along the thickness direction of the core body; the upper layer is composed of wood pulp, chitin fiber and sodium polyacrylate resin according to the mass ratio of 5: 2: 3-4: 3: 3; the middle layer is prepared by mixing wormwood fiber, polyester and polypropylene fiber according to the mass ratio of 3: 4: 3; the lower layer is composed of fluff pulp, straw fibers and sodium polyacrylate resin according to the mass ratio of 4: 2: 4-3: 3: 4; and the thickness ratio of the upper layer to the middle layer to the lower layer is 1: 2: 1-1: 3: 1. The sanitary napkin has the effects of strong water absorption, side leakage prevention, antibiosis and the like, and the use performance of the sanitary napkin is improved.

Description

Technical Field

[0001] This invention relates to the field of sanitary products technology, and more specifically to a fully hydrophilic, true fan-shaped sanitary napkin with an extended core and its preparation method. Background Technology

[0002] Traditional sanitary napkins typically use water-repellent materials, such as polypropylene spunbond nonwoven fabric, for the outer layer in addition to the core. This can cause a sticky feeling when in contact with the skin, easily triggering allergies or discomfort. The side wings are also mostly made of water-repellent materials, which can easily create liquid retention areas at the junction with the core, and lack dynamic drainage structures.

[0003] Traditional sanitary napkins have a flat core structure that is only located in the middle of the napkin body, which limits the area for absorbing blood. In addition, the uneven distribution of SAP super absorbent resin results in slow absorption and high rewetting rate. Most importantly, the current core material is composed of fluff pulp, super absorbent resin and binder, which has poor absorbency and is prone to tearing over time, making it inconvenient for consumers. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a fully hydrophilic, true fan-shaped sanitary napkin with an extended core and a method for preparing the same.

[0005] This invention provides a fully hydrophilic, true fan-tail shaped sanitary napkin with an extended core. The sanitary napkin comprises, from top to bottom, a hydrophilic surface layer, a diversion layer, a core, and a bottom layer. The core extends along the length of the sanitary napkin to its end and is integrally formed with the end, with one end forming a true fan tail shape. The core comprises, along its thickness direction, an upper layer, a middle layer, and a lower layer. The upper layer is composed of wood pulp, chitin fiber, and sodium polyacrylate resin in a mass ratio of 5:2:3-4:3:3. The middle layer is made of a mixture of artemisia fiber, polyester, and polypropylene in a mass ratio of 3:4:3. The lower layer is composed of fluff pulp, straw fiber, and sodium polyacrylate resin in a mass ratio of 4:2:4-3:3:4. The thickness ratio of the upper, middle, and lower layers is 1:2:1-1:3:1.

[0006] Compared with existing technologies, the hydrophilic surface layer, the flow guiding layer, and the core all use hydrophilic materials to ensure rapid liquid penetration and reduce backflow, thereby improving dryness.

[0007] Because the true fan-tail shaped core extends to both sides to form a true fan-tail structure, it expands the liquid absorption area and optimizes liquid distribution, reducing the risk of side leakage. Since it is suitable for athletes and other high-intensity individuals, or those who sit for long periods or can only sleep lying down, the end of the fan-tail structure also has a core structure. Therefore, the fan-tail structure design allows for rapid liquid absorption, quick water retention, and penetration into the interior, effectively preventing leakage. Experimental verification shows that the sanitary napkin of this invention, with a length of 24mm, has an absorbency of up to 34.2g (calculated in the laboratory in ml units, with 1ml as the default value of 1g), significantly improving absorbency compared to currently available daily sanitary napkins (which only absorb 15ml). Furthermore, the fan-tail structure's outward-radiating design significantly increases the coverage area on the skin, further increasing liquid absorption. Therefore, the fan-tail structure of this invention, combined with the upper and lower extension design of the core, enhances the continuity of the absorbent body and improves leak-proof performance.

[0008] The upper layer of the core contains wood pulp that rapidly absorbs liquid, chitosan fiber for antibacterial and bacteriostatic effects, and sodium polyacrylate resin for efficient water retention. These three elements work synergistically to achieve rapid absorption and long-lasting water retention. The middle layer contains artemisia fiber for antibacterial and soothing effects, while polyester and polypropylene provide a supporting structure, forming channels to promote lateral liquid diffusion. The lower layer contains fluff pulp and straw fiber to enhance structural strength, and sodium polyacrylate resin to further lock in water and prevent leakage. A thickness design ranging from 1:2:1 to 1:3:1 balances absorption speed and water retention capacity, with a thicker middle layer to enhance flow efficiency. Therefore, the core design ensures that even when sleeping on one's side, there is no risk of leakage.

[0009] Furthermore, the basis weight of the upper layer of the core is 28-35 g / m³. 2 The weight of the middle layer is 18-25 g / m³. 2 The fluffiness is 9-12cm 3 / g; the particle size of the sodium polyacrylate resin is 100-200μm; the length of the wood pulp fiber in the upper core layer is 1-3mm, and the length of the chitin fiber is 3-5mm; the length of the artemisia fiber in the middle core layer is 2-4mm; the length of the fluff pulp fiber in the lower core layer is 1-3mm, and the length of the straw fiber is 2-4mm.

[0010] Top layer weight 28-35g / m 2To ensure rapid absorption, the high loft of the middle layer increases flow channels and enhances liquid diffusion speed. The bottom layer's basis weight matches the top layer, enhancing overall structural stability. Sodium polyacrylate resin particles with a diameter of 100-200μm balance absorption speed and water retention capacity; smaller particles accelerate absorption, while larger particles extend water retention time. The length difference between the top layer wood pulp (1-3mm) and chitosan (3-5mm) forms an interwoven structure, increasing the density of the water-absorbing network; the middle layer of artemisia fiber (2-4mm) interweaves with synthetic fibers, enhancing the release of antibacterial components; the bottom layer of fluff pulp (1-3mm) and straw fiber (2-4mm) optimizes structural strength and water absorption.

[0011] Furthermore, the hydrophilic surface layer is made of cotton fiber, bamboo pulp fiber, and modified viscose fiber mixed in a mass ratio of 5:2:3-4:3:3, wherein the modified viscose fiber is treated with hydrophilic silicone oil and nano-silver antibacterial agent; the basis weight of the hydrophilic surface layer is 35-45 g / m². 2 The thickness is 0.3-0.5mm; the cotton fiber length is 3-5mm, the bamboo pulp fiber length is 2-4mm, and the modified viscose fiber length is 3-5mm.

[0012] Compared to existing technologies, modified viscose fibers treated with hydrophilic silicone oil and nano-silver composites exhibit enhanced hydrophilicity and broad-spectrum antibacterial properties. Nano-silver achieves long-lasting bactericidal effects by disrupting bacterial DNA, while chitosan fibers synergistically enhance the antibacterial effect. The synergistic combination of cotton fibers, bamboo pulp fibers, and modified viscose fibers provides a soft touch, enhances moisture absorption, and improves overall hydrophilicity. The weight and thickness balance softness and strength, ensuring a close fit to the skin and resistance to breakage.

[0013] Furthermore, the flow-guiding layer is a mesh structure made of hydrophilic polyester fiber and cotton fiber mixed in a mass ratio of 6:4; the basis weight is 12-15 g / m³. 2 The mesh diameter is 0.6-1mm; the lengths of the hydrophilic polyester fiber and the cotton fiber are 3-5mm respectively.

[0014] The hydrophilic polyester fiber is polyethylene terephthalate fiber modified with polyethylene glycol. The modification process is as follows: the polyethylene terephthalate fiber is placed in a polyethylene glycol solution with a mass fraction of 5%-8% and immersed for 30-40 minutes at a temperature of 80-90℃ and a pressure of 0.1-0.2MPa. Then it is dried at 120-130℃ for 15-20 minutes, with a moisture content ≥8%, a basis weight of 12-15g / m², and a mesh diameter of 0.6-1mm.

[0015] Compared to existing technologies, the hydrophilic polyester fiber and cotton fiber (6:4) are blended into a mesh structure. The cotton fiber enhances hydrophilicity, while the polyester fiber provides strength. The mesh diameter of 0.6-1mm promotes rapid liquid diffusion and reduces local aggregation. The fiber length of 3-5mm optimizes the uniformity of the mesh structure and improves flow efficiency.

[0016] Furthermore, the bottom layer is a film made of polyethylene and starch-based composite material in a mass ratio of 7:3, with a thickness of 18-25 μm, and a pressure-sensitive adhesive layer is provided on the side of the bottom layer away from the core; wherein, the starch-based polymeric material is a blend of corn starch and polybutylene adipate-terephthalate, and the mass ratio of corn starch to polybutylene adipate-terephthalate is 6:4-5:5.

[0017] Compared with existing technologies, the combination of polyethylene and starch-based composite materials (7:3) with corn starch (6:4-5:5) improves biodegradability, polybutylene adipate-terephthalate enhances flexibility, balances environmental friendliness and mechanical properties, and the pressure-sensitive adhesive layer provides stable adhesion while reducing skin irritation.

[0018] The second aspect of the present invention provides a method for preparing the sanitary napkin, comprising the following steps: preparing modified viscose fiber, then mixing cotton fiber, bamboo pulp fiber and modified viscose fiber in a certain proportion, and preparing spunlace nonwoven fabric by hydroentangling process to obtain a hydrophilic surface layer;

[0019] The upper, middle and lower layers of the core are prepared separately, and the upper, middle and lower layers are sequentially composited. The three-layer composite core is formed by hot pressing, and one end of the core is extended to both sides to form a true fan tail structure to obtain the core.

[0020] Preparation of the guide layer and the bottom layer;

[0021] The sanitary napkin is obtained by sequentially laminating a hydrophilic surface layer, a flow-guiding layer, a core, and a bottom layer. Further, the process for preparing the modified viscose fiber is as follows: the modified viscose fiber is immersed in a 2%-3% (w / w) hydrophilic silicone oil solution for 10-15 minutes, removed and air-dried, then immersed in a 0.5%-1% (w / w) nano-silver antibacterial agent solution for 8-12 minutes, removed and dried at 60-70°C; the amount of nano-silver antibacterial agent added to the hydrophilic surface layer is 0.5-1% of the mass of the modified viscose fiber.

[0022] The specific process of producing spunlace nonwoven fabric using the spunlace process is as follows:

[0023] Cotton fiber, bamboo pulp fiber and modified viscose fiber are added to a cotton blender in proportion, the mixing speed is 800-1000 r / min, and the mixing time is 15-20 min;

[0024] The mixed fibers are fed into a carding machine at a carding speed of 15-20 m / min to form a fiber web.

[0025] The fiber web is treated by a hydroentangling machine with a hydroentangling pressure of 8-12 MPa and 3-5 hydroentangling cycles. Then it is dried at 100-110℃ for 2-3 minutes to produce a hydroentangled nonwoven fabric, which is the hydrophilic surface layer.

[0026] Furthermore, the preparation process of the upper layer of the core is as follows: wood pulp, chitin fiber and sodium polyacrylate resin are put into a mixer in proportion, the mixing speed is 500-700 r / min, the mixing time is 10-15 min, and then it is formed by a molding machine with a molding thickness of 0.2-0.3 mm.

[0027] The preparation process of the middle layer is as follows: Artemisia argyi fiber, polyester and polypropylene are put into a mixer in a mass ratio of 3:4:3. The mixing speed is 600-800 r / min and the mixing time is 12-18 min. The mixture is then treated by a hot air bonding machine with a hot air temperature of 130-150℃ and a hot air speed of 15-20 m / s to produce a high-loft composite fiber layer with a thickness of 0.4-0.6 mm.

[0028] The lower layer preparation process is as follows: fluff pulp, straw fiber and super absorbent resin are put into a mixer in proportion, the mixing speed is 500-700 r / min, the mixing time is 10-15 min, and then formed by a molding machine with a molding thickness of 0.2-0.3 mm.

[0029] The composite molding process is as follows: the upper, middle and lower layers are stacked in sequence and sent into a hot press. Under the conditions of 85-100℃ and 3.5-5MPa, the layers are hot-pressed for 12-20 seconds to form a three-layer composite core that extends vertically. At the same time, one end of the core extends to both sides to form a true fan tail structure.

[0030] Furthermore, the process for preparing the flow guide layer is as follows:

[0031] Hydrophilic polyester fiber and cotton fiber are fed into the opening machine at a mass ratio of 6:4. The opening speed is 600-800 r / min and the opening time is 10-15 min.

[0032] After being opened, the fibers are laid out using a web-laying machine at a speed of 12-16 m / min to form a uniform fiber layer.

[0033] The fiber layer is processed by a hot rolling mill at a temperature of 120-140℃, a pressure of 2-3MPa, and a speed of 10-12m / min to form a mesh structure, which is the flow guiding layer.

[0034] The preparation process of the bottom layer is as follows:

[0035] Biodegradable polyethylene and starch-based polymer materials are fed into an extruder at a mass ratio of 7:3. The extrusion temperature is 160-180℃ and the screw speed is 100-120r / min. The material is then extruded into a film.

[0036] The film is cooled by a cooling roller at a temperature of 20-30℃. Then, pressure-sensitive adhesive is coated on one side of the film at a coating amount of 15-20 g / m². The film is then dried at 60-70℃ for 1-2 minutes to obtain the bottom layer.

[0037] Furthermore, the composite is prepared by stacking the hydrophilic surface layer, the flow guiding layer, the core, and the bottom layer in sequence and feeding them into the composite machine.

[0038] The laminating machine operates at a pressure of 2-3 MPa and a laminating speed of 10-15 m / min. After lamination, the product is slit by a slitting machine at a speed of 8-12 m / min to obtain the sanitary napkin.

[0039] As can be seen from the above technical solution, the core innovation of this invention lies in the structure and composition of the core, as well as the composition of the hydrophilic surface layer, the diversion layer, and the bottom layer. The fan-shaped surface is made of hydrophilic fabric, and the core is set inside the fan-shaped surface, so that the entire surface of the sanitary napkin has water absorption function, with a large water absorption capacity and prevention of side leakage. The upper layer of the core consists of wood pulp (fast absorption) + chitosan (antibacterial) + sodium polyacrylate (water-locking) to form a "absorption-antibacterial-water-locking" ternary system. The amino group of chitosan and the silver ions of nano-silver synergistically enhance the antibacterial effect. The middle layer consists of artemisia fiber (antibacterial and soothing) + polyester / polypropylene (support structure). The volatile components of artemisia are slowly released through the fiber gaps, forming a double antibacterial barrier with chitosan. At the same time, the high-loft structure promotes liquid diffusion. The bottom layer consists of fluff pulp (fast conduction) + straw fiber (reinforcement) + sodium polyacrylate (water-locking). The porous structure of straw fiber adsorbs liquid and synergistically extends the water-locking time with resin.

[0040] Synergistic effect of components in the hydrophilic surface layer: cotton fiber (softness) + bamboo pulp fiber (moisture absorption) + modified viscose fiber (hydrophilic + antibacterial): cotton and bamboo pulp provide basic properties, modified viscose fiber enhances hydrophilicity through silicone oil, and nano silver and chitin form an antibacterial network to synergistically inhibit bacterial growth.

[0041] Synergistic effect of components in the flow guide layer: moderately hydrophilic polyester fiber (strength) + cotton fiber (hydrophilic): polyester fiber maintains the network structure, cotton fiber enhances hydrophilicity, and the mesh design promotes lateral diffusion of liquid and reduces local pressure.

[0042] Synergy of underlying components: Polyethylene (sealing) + starch-based materials (degradability): Polyethylene provides a physical barrier, while starch-based materials gradually degrade after disposal, reducing the environmental burden. The ratio of corn starch to polybutylene adipate-terephthalate is optimized to balance mechanical and degradation performance.

[0043] The gradient design of flow guidance, absorption, and water retention: the hydrophilic surface layer allows for rapid penetration, the flow guidance layer diffuses laterally, the core has a three-layer gradient absorption, and the bottom layer is sealed to retain water. These four systems work together to form a complete liquid management system. Attached Figure Description

[0044] Appendix Figure 1 This is a plan view of the sanitary napkin of the present invention. Detailed Implementation

[0045] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1

[0047] A type of fully hydrophilic, true fan-shaped sanitary napkin with an extended core, see [link / reference]. Figure 1 The sanitary napkin comprises, from top to bottom, a hydrophilic surface layer, a diversion layer, a core, and a bottom layer. The core extends along the length of the sanitary napkin to its end and is integrally formed with the end, with one end having a true fan-tail shape. Along its thickness, the core comprises an upper layer, a middle layer, and a lower layer. The upper layer is composed of wood pulp, chitin fiber, and sodium polyacrylate resin in a mass ratio of 5:2:3. The middle layer is made of a mixture of artemisia fiber, polyester, and polypropylene in a mass ratio of 3:4:3. The lower layer is composed of fluff pulp, straw fiber, and sodium polyacrylate resin in a mass ratio of 4:2:4. The thickness ratio of the upper, middle, and lower layers is 1:2:1. The weight of the upper core layer is 28 g / m². 2 The weight of the middle layer is 18 g / m³. 2 The fluffiness is 9cm 3 / g; the particle size of sodium polyacrylate resin is 100μm; the length of wood pulp fiber in the upper core layer is 1mm, and the length of chitin fiber is 3mm; the length of artemisia fiber in the middle core layer is 2mm; the length of fluff pulp fiber in the lower core layer is 1mm, and the length of straw fiber is 2mm. The hydrophilic surface layer is made of cotton fiber, bamboo pulp fiber and modified viscose fiber in a mass ratio of 5:2:3, wherein the modified viscose fiber is treated with hydrophilic silicone oil and nano silver antibacterial agent; the basis weight of the hydrophilic surface layer is 35g / m². 2 The thickness is 0.3mm; the cotton fiber length is 3mm, the bamboo pulp fiber length is 2mm, and the modified viscose fiber length is 3mm. The flow-guiding layer is a mesh structure made of hydrophilic polyester fiber and cotton fiber in a mass ratio of 6:4; the basis weight is 12g / m². 2The mesh diameter is 0.6 mm; the lengths of the hydrophilic polyester fiber and the cotton fiber are both 3 mm. The hydrophilic polyester fiber is polyethylene terephthalate fiber modified with polyethylene glycol. The modification process is as follows: the polyethylene terephthalate fiber is placed in a 5% polyethylene glycol solution and impregnated for 30 min at a temperature of 80℃ and a pressure of 0.1 MPa, and then dried at 120℃ for 15 min. Its moisture content is ≥8%, its basis weight is 12 g / m², and its mesh diameter is 0.6 mm.

[0048] The bottom layer is a thin film made of polyethylene and starch-based composite material in a mass ratio of 7:3, with a thickness of 18μm, and a pressure-sensitive adhesive layer is provided on the side of the bottom layer away from the core; wherein, the starch-based polymeric material is a blend of corn starch and polybutylene adipate-terephthalate, and the mass ratio of corn starch to polybutylene adipate-terephthalate is 6:4.

[0049] The above-mentioned method for preparing sanitary napkins includes the following steps:

[0050] Modified viscose fiber was prepared, and then cotton fiber, bamboo pulp fiber and modified viscose fiber were mixed in proportion and made into spunlace nonwoven fabric by hydroentangling process to obtain hydrophilic surface layer;

[0051] The upper, middle and lower layers of the core are prepared separately, and the upper, middle and lower layers are sequentially composited. The three-layer composite core is formed by hot pressing, and one end of the core is extended to both sides to form a true fan tail structure to obtain the core.

[0052] Preparation of the guide layer and the bottom layer;

[0053] The sanitary napkin is obtained by sequentially laminating a hydrophilic surface layer, a diversion layer, a core, and a bottom layer. The process for preparing the modified viscose fiber is as follows: the modified viscose fiber is immersed in a 2% (w / w) hydrophilic silicone oil solution for 10 minutes, removed and air-dried, then immersed in a 0.5% (w / w) nano-silver antibacterial agent solution for 8 minutes, removed and dried at 60°C; the amount of nano-silver antibacterial agent added to the hydrophilic surface layer is 0.5% of the mass of the modified viscose fiber.

[0054] The specific process of producing spunlace nonwoven fabric using the spunlace process is as follows:

[0055] Cotton fiber, bamboo pulp fiber and modified viscose fiber are added to a cotton blender in proportion, the mixing speed is 800 r / min and the mixing time is 15 min;

[0056] The mixed fibers are fed into a carding machine at a carding speed of 15 m / min to form a fiber web.

[0057] The fiber web is processed by a hydroentangling machine with a hydroentangling pressure of 8 MPa and a hydroentangling number of 3 times. Then it is dried at 100°C for 2 minutes to produce a hydroentangled nonwoven fabric, which is the hydrophilic surface layer.

[0058] The preparation process of the upper layer of the core is as follows: wood pulp, chitin fiber and sodium polyacrylate resin are put into a mixer in proportion, the mixing speed is 500 r / min and the mixing time is 10 min, and then it is formed by a molding machine with a molding thickness of 0.2 mm.

[0059] The preparation process of the middle layer is as follows: Artemisia argyi fiber, polyester and polypropylene are put into a mixer in a mass ratio of 3:4:3. The mixing speed is 600-800 r / min and the mixing time is 12-18 min. The mixture is then treated by a hot air bonding machine with a hot air temperature of 130-150℃ and a hot air speed of 15-20 m / s to produce a high-loft composite fiber layer with a thickness of 0.4-0.6 mm.

[0060] The lower layer preparation process is as follows: fluff pulp, straw fiber and super absorbent resin are put into a mixer in proportion, the mixing speed is 500 r / min, the mixing time is 10 min, and then the mixture is formed by a molding machine with a molding thickness of 0.2 mm.

[0061] The composite molding process is as follows: the upper, middle and lower layers are stacked in sequence and sent into a hot press. Under the conditions of 85℃ and 3.5MPa, the layers are hot-pressed for 12 seconds to form a three-layer composite core that extends vertically. At the same time, one end of the core extends to both sides to form a true fan tail structure.

[0062] The process of preparing the flow guide layer is as follows:

[0063] Hydrophilic polyester fiber and cotton fiber were fed into the opening machine at a mass ratio of 6:4, the opening speed was 600 r / min, and the opening time was 10 min.

[0064] After being opened, the fibers are laid out using a web-laying machine at a speed of 12m / min to form a uniform fiber layer.

[0065] The fiber layer is processed by a hot rolling mill at a temperature of 120℃, a pressure of 2MPa, and a speed of 10m / min to form a mesh structure, which is the flow guiding layer.

[0066] The preparation process of the bottom layer is as follows:

[0067] Biodegradable polyethylene and starch-based polymer materials are fed into an extruder at a mass ratio of 7:3. The extrusion temperature is 160℃ and the screw speed is 100r / min. The material is then extruded into a film.

[0068] The film is cooled by a cooling roller at a temperature of 20°C. Then, pressure-sensitive adhesive is coated on one side of the film at a coating amount of 15 g / m². The film is then dried at 60°C for 1 minute to obtain the bottom layer.

[0069] The composite process involves stacking the hydrophilic surface layer, the flow guiding layer, the core, and the bottom layer in sequence, and then feeding them into the laminating machine.

[0070] The laminating machine operates at a pressure of 2 MPa and a laminating speed of 10 m / min. After lamination, the product is slit by a slitting machine at a speed of 8 m / min to obtain the sanitary napkin.

[0071] Example 2

[0072] A type of fully hydrophilic, true fan-shaped sanitary napkin with an extended core, see [link / reference]. Figure 1 The sanitary napkin comprises, from top to bottom, a hydrophilic surface layer, a diversion layer, a core, and a bottom layer. The core extends along the length of the sanitary napkin to the end and is integrally formed with the end, with one end having a true fan-tail shape. The core comprises, along its thickness, an upper layer, a middle layer, and a lower layer. The upper layer is composed of wood pulp, chitin fiber, and sodium polyacrylate resin in a mass ratio of 4:3:3. The middle layer is made of a mixture of artemisia fiber, polyester, and polypropylene in a mass ratio of 3:4:3. The lower layer is composed of fluff pulp, straw fiber, and sodium polyacrylate resin in a mass ratio of 3:3:4. The thickness ratio of the upper, middle, and lower layers is 1:3:1.

[0073] The weight of the upper layer of the core is 35 g / m². 2 The middle layer has a basis weight of 25 g / m³. 2 The fluffiness is 12cm 3 / g; the particle size of sodium polyacrylate resin is 200μm; the length of wood pulp fiber in the upper core is 3mm, and the length of chitin fiber is 5mm; the length of artemisia fiber in the middle core is 4mm; the length of fluff pulp fiber in the lower core is 3mm, and the length of straw fiber is 4mm.

[0074] The hydrophilic surface layer is made of a mixture of cotton fiber, bamboo pulp fiber, and modified viscose fiber in a mass ratio of 4:3:3. The modified viscose fiber is treated with a hydrophilic silicone oil and a nano-silver antibacterial agent. The basis weight of the hydrophilic surface layer is 45 g / m². 2 The thickness is 0.5mm; the cotton fiber length is 5mm, the bamboo pulp fiber length is 4mm, and the modified viscose fiber length is 5mm. The flow-guiding layer is a mesh structure made of hydrophilic polyester fiber and cotton fiber in a mass ratio of 6:4; the basis weight is 15g / m². 2The mesh diameter is 1 mm; the lengths of the hydrophilic polyester fiber and the cotton fiber are both 5 mm. The hydrophilic polyester fiber is polyethylene terephthalate fiber modified with polyethylene glycol. The modification process is as follows: the polyethylene terephthalate fiber is placed in a polyethylene glycol solution with a mass fraction of 8%, immersed for 40 min at a temperature of 90℃ and a pressure of 0.2 MPa, and then dried at 130℃ for 20 min. Its moisture content is ≥8%, its basis weight is 15 g / m², and its mesh diameter is 1 mm.

[0075] The bottom layer is a film made of polyethylene and starch-based composite material in a mass ratio of 7:3, with a thickness of 18-25μm, and a pressure-sensitive adhesive layer is provided on the side of the bottom layer away from the core; wherein, the starch-based polymeric material is a blend of corn starch and polybutylene adipate-terephthalate, and the mass ratio of corn starch to polybutylene adipate-terephthalate is 5:5.

[0076] The above-mentioned method for preparing sanitary napkins includes the following steps:

[0077] Modified viscose fiber was prepared, and then cotton fiber, bamboo pulp fiber and modified viscose fiber were mixed in proportion and made into spunlace nonwoven fabric by hydroentangling process to obtain hydrophilic surface layer;

[0078] The upper, middle and lower layers of the core are prepared separately, and the upper, middle and lower layers are sequentially composited. The three-layer composite core is formed by hot pressing, and one end of the core is extended to both sides to form a true fan tail structure to obtain the core.

[0079] Preparation of the guide layer and the bottom layer;

[0080] The sanitary napkin is obtained by sequentially combining the hydrophilic surface layer, the diversion layer, the core, and the bottom layer.

[0081] The process for preparing modified viscose fiber is as follows: the modified viscose fiber is immersed in a 3% (w / w) hydrophilic silicone oil solution for 15 minutes, removed and air-dried, then immersed in a 1% (w / w) nano-silver antibacterial agent solution for 12 minutes, removed and dried at 70°C; the amount of nano-silver antibacterial agent added to the hydrophilic surface layer is 1% of the mass of the modified viscose fiber;

[0082] The specific process of producing spunlace nonwoven fabric using the spunlace process is as follows:

[0083] Cotton fiber, bamboo pulp fiber and modified viscose fiber are added to a cotton blender in proportion, the mixing speed is 1000 r / min and the mixing time is 20 min;

[0084] The mixed fibers are fed into a carding machine at a carding speed of 20 m / min to form a fiber web.

[0085] The fiber web is processed by a hydroentangling machine with a hydroentangling pressure of 12MPa and a hydroentangling number of 5 times. Then it is dried at 110℃ for 3 minutes to make a hydroentangled nonwoven fabric, which is the hydrophilic surface layer.

[0086] The preparation process of the upper layer of the core is as follows: wood pulp, chitin fiber and sodium polyacrylate resin are put into a mixer in proportion, the mixing speed is 700 r / min and the mixing time is 15 min, and then it is formed by a molding machine with a molding thickness of 0.3 mm.

[0087] The middle layer preparation process is as follows: Artemisia argyi fiber, polyester and polypropylene are put into a mixer in a mass ratio of 3:4:3, the mixing speed is 800 r / min and the mixing time is 18 min. After being processed by a hot air bonding machine, the hot air temperature is 150℃ and the hot air speed is 20 m / s to make a high-loft composite fiber layer with a thickness of 0.6 mm.

[0088] The lower layer preparation process is as follows: fluff pulp, straw fiber and super absorbent resin are put into a mixer in proportion, the mixing speed is 700 r / min, the mixing time is 15 min, and then the mixture is formed by a molding machine with a molding thickness of 0.3 mm.

[0089] The composite molding process is as follows: the upper, middle and lower layers are stacked in sequence and sent into a hot press. Under the conditions of 100℃ and 5MPa, the layers are hot-pressed for 20 seconds to form a three-layer composite core that extends vertically. At the same time, one end of the core extends to both sides to form a true fan tail structure.

[0090] The process of preparing the flow guide layer is as follows:

[0091] Hydrophilic polyester fiber and cotton fiber were fed into the opening machine at a mass ratio of 6:4, the opening speed was 800 r / min, and the opening time was 15 min.

[0092] After being opened, the fibers are laid out using a web-laying machine at a speed of 16 m / min to form a uniform fiber layer.

[0093] The fiber layer is processed by a hot rolling mill at a temperature of 140℃, a pressure of 3MPa, and a speed of 12m / min to form a mesh structure, which is the flow guiding layer.

[0094] The preparation process of the bottom layer is as follows:

[0095] Biodegradable polyethylene and starch-based polymer materials are fed into an extruder at a mass ratio of 7:3. The extrusion temperature is 180℃ and the screw speed is 120r / min. The material is then extruded into a film.

[0096] The film is cooled by a cooling roller at a temperature of 30°C. Then, pressure-sensitive adhesive is coated on one side of the film at a coating amount of 20 g / m². The film is then dried at 70°C for 2 minutes to obtain the bottom layer.

[0097] The composite process involves stacking the hydrophilic surface layer, the flow guiding layer, the core, and the bottom layer in sequence, and then feeding them into the laminating machine.

[0098] The laminating machine operates at a pressure of 3 MPa and a laminating speed of 15 m / min. After lamination, the product is slit by a slitting machine at a speed of 12 m / min to obtain the sanitary napkin.

[0099] Example 3

[0100] A type of fully hydrophilic, true fan-shaped sanitary napkin with an extended core, see [link / reference]. Figure 1 The sanitary napkin comprises, from top to bottom, a hydrophilic surface layer, a diversion layer, a core, and a bottom layer. The core extends along the length of the sanitary napkin to the end and is integrally formed with the end, with one end having a true fan-tail shape. The core comprises, along its thickness, an upper layer, a middle layer, and a lower layer. The upper layer is composed of wood pulp, chitin fiber, and sodium polyacrylate resin in a mass ratio of 4:2.5:3. The middle layer is made of a mixture of artemisia fiber, polyester, and polypropylene in a mass ratio of 3:4:3. The lower layer is composed of fluff pulp, straw fiber, and sodium polyacrylate resin in a mass ratio of 4:2.5:4. The thickness ratio of the upper, middle, and lower layers is 1:2.5:1.

[0101] The weight of the upper layer of the core is 30 g / m². 2 The weight of the middle layer is 21 g / m³. 2 The fluffiness is 10cm 3 / g; the particle size of sodium polyacrylate resin is 150μm; the length of wood pulp fiber in the upper core is 2mm, and the length of chitin fiber is 4mm; the length of artemisia fiber in the middle core is 3mm; the length of fluff pulp fiber in the lower core is 2mm, and the length of straw fiber is 3mm.

[0102] The hydrophilic surface layer is made of cotton fiber, bamboo pulp fiber, and modified viscose fiber in a mass ratio of 5:2.5:3, wherein the modified viscose fiber is treated with hydrophilic silicone oil and nano-silver antibacterial agent; the basis weight of the hydrophilic surface layer is 40 g / m². 2 The thickness is 0.4 mm; the cotton fiber length is 4 mm, the bamboo pulp fiber length is 3 mm, and the modified viscose fiber length is 4 mm. The flow-guiding layer is a mesh structure made of hydrophilic polyester fiber and cotton fiber in a mass ratio of 6:4; the basis weight is 13 g / m². 2 The mesh diameter is 0.8 mm; the lengths of the hydrophilic polyester fiber and the cotton fiber are both 4 mm. The hydrophilic polyester fiber is polyethylene terephthalate fiber modified with polyethylene glycol. The modification process is as follows: the polyethylene terephthalate fiber is placed in a 6% (w / w) polyethylene glycol solution, immersed for 35 min at 85°C and 0.15 MPa, and then dried at 125°C for 16 min. Its moisture content is ≥8%, its basis weight is 14 g / m², and its mesh diameter is 0.7 mm.

[0103] The bottom layer is a film made of polyethylene and starch-based composite material in a mass ratio of 7:3, with a thickness of 20μm, and a pressure-sensitive adhesive layer is provided on the side of the bottom layer away from the core; wherein, the starch-based polymeric material is a blend of corn starch and polybutylene adipate-terephthalate, and the mass ratio of corn starch to polybutylene adipate-terephthalate is 5:4.

[0104] The above-mentioned method for preparing sanitary napkins includes the following steps:

[0105] Modified viscose fiber was prepared, and then cotton fiber, bamboo pulp fiber and modified viscose fiber were mixed in proportion and made into spunlace nonwoven fabric by hydroentangling process to obtain hydrophilic surface layer;

[0106] The upper, middle and lower layers of the core are prepared separately, and the upper, middle and lower layers are sequentially composited. The three-layer composite core is formed by hot pressing, and one end of the core is extended to both sides to form a true fan tail structure to obtain the core.

[0107] Preparation of the guide layer and the bottom layer;

[0108] The sanitary napkin is obtained by sequentially combining the hydrophilic surface layer, the diversion layer, the core, and the bottom layer.

[0109] The process for preparing modified viscose fiber is as follows: the modified viscose fiber is immersed in a 2.5% (w / w) hydrophilic silicone oil solution for 13 minutes, removed and air-dried, then immersed in a 0.5%-1% (w / w) nano-silver antibacterial agent solution for 10 minutes, removed and dried at 65°C; the amount of nano-silver antibacterial agent added to the hydrophilic surface layer is 0.7% of the mass of the modified viscose fiber;

[0110] The specific process of producing spunlace nonwoven fabric using the spunlace process is as follows:

[0111] Cotton fiber, bamboo pulp fiber and modified viscose fiber are added to a cotton blender in proportion, the mixing speed is 900 r / min and the mixing time is 18 min;

[0112] The mixed fibers are fed into a carding machine at a carding speed of 18 m / min to form a fiber web.

[0113] The fiber web is processed by a hydroentangling machine with a hydroentangling pressure of 10 MPa and a hydroentangling number of 4 times. Then it is dried at 105℃ for 2.5 minutes to produce a hydroentangled nonwoven fabric, which is the hydrophilic surface layer.

[0114] The preparation process of the upper layer of the core is as follows: wood pulp, chitin fiber and sodium polyacrylate resin are put into a mixer in proportion, the mixing speed is 600 r / min and the mixing time is 12 min, and then it is formed by a molding machine with a molding thickness of 0.25 mm.

[0115] The middle layer preparation process is as follows: Artemisia argyi fiber, polyester and polypropylene are put into a mixer in a mass ratio of 3:4:3, the mixing speed is 700 r / min and the mixing time is 15 min. After being processed by a hot air bonding machine, the hot air temperature is 140℃ and the hot air speed is 17 m / s to make a high-loft composite fiber layer with a thickness of 0.5 mm.

[0116] The lower layer preparation process is as follows: fluff pulp, straw fiber and super absorbent resin are put into a mixer in proportion, the mixing speed is 600 r / min, the mixing time is 13 min, and then the mixture is formed by a molding machine with a molding thickness of 0.25 mm.

[0117] The composite molding process is as follows: the upper, middle and lower layers are stacked in sequence and fed into a hot press. The hot press is carried out for 15 seconds at a temperature of 90℃ and a pressure of 4MPa to form a three-layer composite core that extends vertically. At the same time, one end of the core extends to both sides to form a true fan tail structure.

[0118] The process of preparing the flow guide layer is as follows:

[0119] Hydrophilic polyester fiber and cotton fiber were fed into the opening machine at a mass ratio of 6:4, the opening speed was 700 r / min, and the opening time was 12 min.

[0120] After being opened, the fibers are laid out using a web-laying machine at a speed of 14 m / min to form a uniform fiber layer.

[0121] The fiber layer is processed by a hot rolling mill at a temperature of 130℃, a pressure of 2.5MPa, and a speed of 11m / min to form a mesh structure, which is the flow guiding layer.

[0122] The preparation process of the bottom layer is as follows:

[0123] Biodegradable polyethylene and starch-based polymer materials are fed into an extruder at a mass ratio of 7:3. The extrusion temperature is 170℃ and the screw speed is 110r / min. The material is then extruded into a film.

[0124] The film is cooled by a cooling roller at a temperature of 25°C. Then, pressure-sensitive adhesive is coated on one side of the film at a coating amount of 18 g / m². The film is then dried at 65°C for 1.5 min to obtain the bottom layer.

[0125] The composite process involves stacking the hydrophilic surface layer, the flow guiding layer, the core, and the bottom layer in sequence, and then feeding them into the laminating machine.

[0126] The laminating machine operates at a pressure of 2.5 MPa and a laminating speed of 12 m / min. After lamination, the product is slit by a slitting machine at a speed of 10 m / min to obtain the sanitary napkin.

[0127] Comparative Example 1

[0128] Taking Example 3 as an example, the difference from Example 3 is that the upper layer of the core is composed of chitin fiber and sodium polyacrylate resin in a mass ratio of 2.5:3, while the other components remain unchanged.

[0129] Comparative Example 2

[0130] Taking Example 3 as an example, the difference from Example 3 is that the upper layer of the core is composed of wood pulp and sodium polyacrylate resin in a mass ratio of 4:3, while the other components remain unchanged.

[0131] Comparative Example 3

[0132] Taking Example 3 as an example, the difference from Example 3 is that the upper core layer is composed of wood pulp and chitin fiber in a mass ratio of 4:4.5, while the other components remain unchanged.

[0133] Comparative Example 4

[0134] Example 3 is an example. Compared with Example 3, the difference is that the lower core layer is composed of fluff pulp and straw fiber in a mass ratio of 4:2.5.

[0135] Comparative Example 5

[0136] Taking Example 3 as an example, the difference from Example 3 is that the lower core layer is composed of fluff pulp and sodium polyacrylate resin in a mass ratio of 4:4.

[0137] Comparative Example 6

[0138] Taking Example 3 as an example, the difference from Example 3 is that the lower core layer is composed of straw fiber and sodium polyacrylate resin in a mass ratio of 2.5:4.

[0139] Comparative Example 7

[0140] Purchase sanitary napkins available on the market, such as Always, daytime use, 240mm.

[0141] The following are the key performance test data for sanitary napkins in Examples 1-3 and Comparative Examples 1-7. The test indicators include absorbency, leak prevention, antibacterial properties, comfort, breathability, and biodegradability. The test methods and data are as follows.

[0142] Test Method Description

[0143] 1. Aspiration volume: Take 2g of the core and place it in 50mL of physiological saline. Calculate the aspiration volume (g / g) after 30min.

[0144] Standard basis: GB / T 8939-2018 "Sanitary Napkins (Patrolleys)" requires an absorbency ratio of ≥7 times (absorbent volume / core mass).

[0145] 2. First leakage time: 0.9% saline solution was continuously added to the center of the sample (at a rate of 1 mL / min), and the time (s) at which the first side leakage / bottom leakage occurred was recorded.

[0146] 3. Lateral diffusion distance: After adding 5 mL of physiological saline, let it stand for 10 min and measure the maximum lateral diffusion distance of the liquid (mm; the smaller the distance, the better the side leakage prevention).

[0147] 4. Breathability: YG461E breathability tester, air permeability under 100Pa pressure (mm / s, the higher the value, the better the breathability).

[0148] 5. Degradation rate: The bottom layer (10g) was placed in a composting environment (58±2℃, humidity 60±5%), and the mass loss rate (%) was calculated after 60 days.

[0149] 6. Skin irritation: 20 volunteers were tested for 3 days (8 hours a day) and rated (1 point for extremely irritating, 5 points for no irritation, average value).

[0150] The results are shown in Table 1.

[0151] Sample number Liquid absorption volume (g / g) Time to first leakage (s) Lateral diffusion distance (mm) Breathability (mm / s) Degradation rate (60 days, %) Skin irritation rating (1-5) Example 1 32.5 280 7.2 18.2 62.3 4.8 Example 2 34.2 310 6.8 19.5 65.7 4.9 Example 3 33.8 300 7.0 18.8 64.5 4.8 Comparative Example 1 21.6 220 10.5 18.5 64.2 4.7 Comparison 2 22.2 270 9.5 18.6 64.3 4.8 Comparative Example 3 24.5 80 12.3 18.4 64.1 4.6 Comparative Example 4 22.3 150 9.8 18.7 64.4 4.7 Comparative Example 5 20.5 260 11.2 18.6 64.3 4.8 Comparative Example 6 25.8 190 10.1 18.5 64.2 4.7 Comparative Example 7 27.8 250 9.5 15.3 18.6 4.5

[0152] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention.

[0153] Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fully hydrophilic, true fan-shaped sanitary napkin with an extended core, characterized in that, The sanitary napkin comprises, from top to bottom, a hydrophilic surface layer, a diversion layer, a core, and a bottom layer. The core extends along the length of the sanitary napkin to the end and is integrally formed with the end, and one end is in the shape of a true fan tail. The core comprises an upper layer, a middle layer, and a lower layer along its thickness direction; the upper layer is composed of wood pulp, chitin fiber, and sodium polyacrylate resin in a mass ratio of 5:2:3-4:3:3; the middle layer is made of a mixture of artemisia fiber, polyester, and polypropylene in a mass ratio of 3:4:3; the lower layer is composed of fluff pulp, straw fiber, and sodium polyacrylate resin in a mass ratio of 4:2:4-3:3:4; and the thickness ratio of the upper, middle, and lower layers is 1:2:1-1:3:

1.

2. The sanitary napkin with a fully hydrophilic true fan-tail shape and an extended core as described in claim 1, characterized in that, The weight of the upper core layer is 28-35 g / m²; the weight of the middle core layer is 18-25 g / m², and the bulkiness is 9-12 cm³ / g; and / or, The sodium polyacrylate resin has a particle size of 100-200 μm; and / or, The wood pulp fibers in the upper layer of the core are 1-3 mm in length, and the chitin fibers are 3-5 mm in length; and / or, The length of the Artemisia argyi fiber in the middle layer of the core is 2-4 mm; and / or, The length of the fluff pulp fibers in the lower layer of the core is 1-3 mm, and the length of the straw fibers is 2-4 mm.

3. The sanitary napkin with a fully hydrophilic true fan-tail shape and an extended core as described in claim 1, characterized in that, The hydrophilic surface layer is made of cotton fiber, bamboo pulp fiber, and modified viscose fiber in a mass ratio of 5:2:3-4:3:3, wherein the modified viscose fiber is treated with a hydrophilic silicone oil and a nano-silver antibacterial agent; and / or, The hydrophilic surface layer has a basis weight of 35-45 g / m² and a thickness of 0.3-0.5 mm; and / or, The cotton fiber is 3-5 mm long, the bamboo pulp fiber is 2-4 mm long, and the modified viscose fiber is 3-5 mm long.

4. The sanitary napkin with a fully hydrophilic true fan-tail shape and an extended core as described in claim 1, characterized in that, The flow-guiding layer is a mesh structure made of hydrophilic polyester fiber and cotton fiber mixed in a mass ratio of 6:4; the basis weight is 12-15 g / m2, and the mesh diameter is 0.6-1 mm; and / or, The lengths of the hydrophilic polyester fiber and the cotton fiber are 3-5 mm, respectively.

5. The sanitary napkin with a fully hydrophilic true fan-tail shape and an extended core as described in claim 1, characterized in that, The bottom layer is a film made of polyethylene and starch-based composite material in a mass ratio of 7:3, with a thickness of 18-25μm, and a pressure-sensitive adhesive layer is provided on the side of the bottom layer away from the core; wherein, the starch-based polymeric material is a blend of corn starch and polybutylene adipate-terephthalate, and the mass ratio of corn starch to polybutylene adipate-terephthalate is 6:4-5:

5.

6. A method for preparing a sanitary napkin as described in any one of claims 1-5, characterized in that, Includes the following steps: Modified viscose fiber was prepared, and then cotton fiber, bamboo pulp fiber and modified viscose fiber were mixed in proportion and made into spunlace nonwoven fabric by hydroentangling process to obtain hydrophilic surface layer; The upper, middle and lower layers of the core are prepared separately, and the upper, middle and lower layers are sequentially composited. The three-layer composite core is formed by hot pressing, and one end of the core is extended to both sides to form a true fan tail structure to obtain the core. Preparation of the guide layer and the bottom layer; The sanitary napkin is obtained by sequentially combining the hydrophilic surface layer, the diversion layer, the core, and the bottom layer.

7. The preparation method according to claim 6, characterized in that, The process for preparing modified viscose fiber is as follows: The modified viscose fiber is immersed in a 2%-3% (w / w) hydrophilic silicone oil solution for 10-15 minutes, removed and air-dried, then immersed in a 0.5%-1% (w / w) nano-silver antibacterial agent solution for 8-12 minutes, removed and dried at 60-70℃; the amount of nano-silver antibacterial agent added to the hydrophilic surface layer is 0.5-1% of the mass of the modified viscose fiber; and / or, The specific process of producing spunlace nonwoven fabric using the spunlace process is as follows: Cotton fiber, bamboo pulp fiber and modified viscose fiber are added to a cotton blender in proportion, the mixing speed is 800-1000 r / min, and the mixing time is 15-20 min; The mixed fibers are fed into a carding machine at a carding speed of 15-20 m / min to form a fiber web. The fiber web is then treated by a hydroentangling machine at a hydroentangling pressure of 8-12 MPa and 3-5 hydroentangling cycles. Finally, it is dried at 100-110℃ for 2-3 minutes to produce a hydroentangled nonwoven fabric, which is the hydrophilic surface layer.

8. The preparation method according to claim 6, characterized in that, The preparation process of the upper layer of the core is as follows: wood pulp, chitin fiber and sodium polyacrylate resin are put into a mixer in proportion, the mixing speed is 500-700 r / min, the mixing time is 10-15 min, and then it is formed by a molding machine with a molding thickness of 0.2-0.3 mm. The preparation process of the middle layer is as follows: Artemisia argyi fiber, polyester and polypropylene are put into a mixer in a mass ratio of 3:4:

3. The mixing speed is 600-800 r / min and the mixing time is 12-18 min. The mixture is then treated by a hot air bonding machine with a hot air temperature of 130-150℃ and a hot air speed of 15-20 m / s to produce a high-loft composite fiber layer with a thickness of 0.4-0.6 mm. The lower layer preparation process is as follows: fluff pulp, straw fiber and super absorbent resin are put into a mixer in proportion, the mixing speed is 500-700 r / min, the mixing time is 10-15 min, and then formed by a molding machine with a molding thickness of 0.2-0.3 mm. The composite molding process is as follows: the upper, middle and lower layers are stacked in sequence and sent into a hot press. Under the conditions of 85-100℃ and 3.5-5MPa, the layers are hot-pressed for 12-20 seconds to form a three-layer composite core that extends vertically. At the same time, one end of the core extends to both sides to form a true fan tail structure.

9. The preparation method according to claim 6, characterized in that, The process of preparing the flow guide layer is as follows: Hydrophilic polyester fiber and cotton fiber are fed into the opening machine at a mass ratio of 6:

4. The opening speed is 600-800 r / min and the opening time is 10-15 min. After being opened, the fibers are laid out using a web-laying machine at a speed of 12-16 m / min to form a uniform fiber layer. The fiber layer is processed by a hot rolling mill at a temperature of 120-140℃, a pressure of 2-3MPa, and a speed of 10-12m / min to form a mesh structure, which is the flow guiding layer. The preparation process of the bottom layer is as follows: Biodegradable polyethylene and starch-based polymer are fed into an extruder at a mass ratio of 7:

3. The extrusion temperature is 160-180℃ and the screw speed is 100-120 r / min. The film is then extruded and formed into a film. The film is cooled by a cooling roller at a temperature of 20-30℃. Pressure-sensitive adhesive is then coated on one side of the film at a coating amount of 15-20 g / m². The film is then dried at 60-70℃ for 1-2 minutes to obtain the bottom layer.

10. The preparation method according to claim 6, characterized in that, The composite is formed by stacking the hydrophilic surface layer, the flow guiding layer, the core, and the bottom layer in sequence and then feeding them into the laminating machine. The laminating machine operates at a pressure of 2-3 MPa and a laminating speed of 10-15 m / min. After lamination, the product is slit by a slitting machine at a speed of 8-12 m / min to obtain the sanitary napkin.

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