An absorbent article having a nanocompliant topsheet and method of making the same

Abstract

This invention discloses an absorbent product with a nano-soft surface layer and its manufacturing method, belonging to the field of sanitary products technology. The sanitary product consists of a nano-soft surface layer, an absorbent core, and a leak-proof bottom layer. The nano-soft surface layer is composed of a nanofiber layer and a surface non-woven fabric, and the nanofiber layer is composed of several nanofibers stacked together. The manufacturing method of the sanitary product includes the following steps: S1, forming a spun fiber layer by electrospinning a spinning solution containing sodium alginate; S2, preliminarily drying and shaping the spun fiber layer; S3, reacting calcium chloride solution with the sodium alginate in the spun fiber layer, transforming the spun fiber layer into a nanofiber layer; S4, completely drying the nanofiber layer; S5, combining the nano-soft surface layer, absorbent core, and leak-proof bottom layer to obtain the absorbent product. The sanitary product of this invention can improve comfort during use.

Description

Technical Field

[0001] This invention relates to the field of hygiene products technology, specifically to an absorbent product with a nano-soft surface layer and its manufacturing method. Background Technology

[0002] As consumers pursue a higher quality of life, the functions of absorbent hygiene products are becoming increasingly diversified. The surface layer of these products needs to come into direct contact with the user's skin. A softer surface layer can significantly improve the comfort of using these products. The surface layer of hygiene products typically uses non-woven fabrics such as hot-air non-woven fabric as raw materials. The fibers in non-woven fabrics are randomly distributed and bonded together. However, the ends of some fibers are not bonded to other fibers, causing the fiber ends to protrude from the surface of the non-woven fabric, forming several burr-like structures. When using these hygiene products, the user's skin comes into contact with and rubs against the surface of the non-woven fabric. The protruding fiber ends on the surface of the non-woven fabric can irritate the skin, causing itching and other symptoms, thus affecting the comfort of the hygiene products. In addition, although non-woven fabrics made using processes such as hot rolling have a smoother surface and fewer fiber ends protruding from the surface, this type of non-woven fabric has poorer fluffiness and softness, which can also affect the comfort of sanitary products. Some sanitary products also have a surface coating formed by applying a solution with specific functions. The coating can improve the smoothness of the surface, but after the coating is applied to the surface, it will affect the overall breathability of the surface layer. Users may experience a stuffy feeling when using sanitary products, which will also affect the comfort of the sanitary products. Summary of the Invention

[0003] To address the technical deficiencies in the prior art, this invention proposes an absorbent product with a nano-flexible surface layer and its manufacturing method, solving the aforementioned technical problems and meeting practical needs. The specific technical solution is as follows: An absorbent product with a nano-soft surface layer includes a nano-soft surface layer, an absorbent core, and a leak-proof bottom layer. The nano-soft surface layer, absorbent core, and leak-proof bottom layer are arranged sequentially along the thickness direction of the absorbent product. The nano-soft surface layer and the leak-proof bottom layer are fixedly connected to each other along the edges and together wrap the absorbent core. The nano-soft surface layer is composed of a nanofiber layer and a surface non-woven fabric in sequence along the thickness direction of the absorbent product. The nanofiber layer is composed of a stack of nanofibers, which include the following components by mass: polyvinyl alcohol, polyethylene oxide, calcium alginate, polyvinylpyrrolidone, and sustained-release factor.

[0004] As a further technical solution of the present invention, the surface nonwoven fabric is selected from either hot-air nonwoven fabric or spunlace nonwoven fabric.

[0005] As a further technical solution of the present invention, the absorbent core is composed of a surface coating layer and a water-absorbing material wrapped inside the coating layer. The coating layer is selected from one of dust-free paper and spunbond nonwoven fabric, and the water-absorbing material is selected from one or a mixture of two of superabsorbent resin and fluff pulp.

[0006] As a further technical solution of the present invention, the leak-proof bottom layer is composed of a waterproof and breathable PE membrane and an SMS non-woven fabric in sequence along the thickness direction of the absorbent product, and the waterproof and breathable PE membrane is located on the side close to the absorbent core.

[0007] As a further technical solution of the present invention, the sustained-release factor is selected from one or more of cetrimonium bromide, nisin, nicotinamide, glycerin, hyaluronic acid, and aloe polysaccharide.

[0008] A method for manufacturing an absorbent article includes the following steps: S1, the surface nonwoven fabric is unwound from the nonwoven fabric roll and conveyed to the side of the electrospinning device near the receiving device. A solution containing sodium alginate is used as the spinning solution. A high voltage electric field is applied through the electrospinning device to make the spinning solution form a Taylor cone at the needle and spray out the spinning fibers. After the spinning fibers move toward the receiving device, they are stacked on the surface of the surface nonwoven fabric to form a spinning fiber layer. S2, the surface nonwoven fabric with the spun fiber layer formed on the surface is immediately dried to allow the solution in the spun fiber layer to evaporate and set. S3, after atomizing the calcium chloride solution, it is evenly sprayed onto the surface of the dried spinning fiber layer. Then, the non-woven surface layer with the spinning fiber layer is placed in a constant temperature and humidity environment and left to stand until the calcium chloride solution reacts with the spinning fiber. S4, after the spun fiber layer reacts with the calcium chloride solution, a nanofiber layer is formed. The nonwoven fabric with the nanofiber layer is dried. The dried nanofiber layer and the nonwoven fabric together form a nano-soft surface layer. S5 is made by sequentially stacking and bonding the nano-soft surface layer, absorbent core, and leak-proof bottom layer, and then cutting it to obtain the absorbent product.

[0009] As a further technical solution of the present invention, the spinning solution comprises the following components by mass: 2%-4% polyvinyl alcohol, 2%-4% polyethylene oxide, 1%-2% sodium alginate, 4%-8% polyvinylpyrrolidone, 0.5%-1% slow-release factor, and 82%-90% water.

[0010] As a further technical solution of the present invention, in step S1, during the electrospinning process of the electrospinning device using the spinning solution, the ambient temperature is 20-30℃, the ambient humidity is 40%-50%, the voltage of the applied high voltage electric field is 15-25KV, the propulsion speed of the spinning solution is 1-2mL / h, and the distance between the needle and the surface nonwoven fabric is 10-20cm.

[0011] As a further technical solution of the present invention, in step S2, the nonwoven surface layer with the spun fiber layer formed on the surface is dried in an environment of 50-60°C for 100-300 seconds to allow some of the solvent in the spun fiber layer to evaporate. In step S4, the nonwoven fabric with the nanofiber layer is dried in an environment of 50-60℃ for 0.5-2 hours.

[0012] As a further technical solution of the present invention, in step S3, the nonwoven surface layer with the spun fiber layer is placed in an environment of 30-50℃ and 100% humidity for 10-30 minutes.

[0013] The beneficial effects of this invention are as follows: This invention discloses a sanitary product with improved comfort through a nano-soft surface layer and its manufacturing method. The sanitary product mainly consists of a nano-soft surface layer, an absorbent core, and a leak-proof bottom layer. The nano-soft surface layer comes into direct contact with the human body through a nanofiber layer. The nanofibers, through their long fiber structure and nanoscale size, give the nanofiber layer soft and smooth properties. The nanofiber layer can isolate the protruding fiber ends on the surface of the non-woven fabric from the human skin, avoiding direct contact between the human skin and the surface of the non-woven fabric. This avoids the burr-like feeling that occurs when the user comes into contact with the nano-soft surface layer during use. Furthermore, the good softness of the nanofiber layer can improve the comfort of the human skin when it comes into contact with the nano-soft surface layer. In the manufacturing process of hygiene products, the electrospinning process is mainly based on the formation of fine spun fibers from a spinning solution containing sodium alginate under the action of a high-voltage electric field. These fibers are then attached to the surface of the nonwoven fabric. Subsequently, calcium chloride solution reacts with the sodium alginate in the spun fibers to form calcium alginate, which gives the nanofiber layer good wet structural integrity. Furthermore, the nano-soft surface layer can release slow-release factors to achieve antibacterial and skin-care functions after contact with water, further improving the comfort of using hygiene products. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of an absorbent product with a nano-flexible surface layer.

[0015] The components are: 1-nano-soft surface layer, 11-nano-fiber layer, 12-surface non-woven fabric, 2-absorbent core, and 3-leak-proof bottom layer. Detailed Implementation

[0016] The embodiments of the present invention will be described below with reference to the accompanying drawings and examples. The embodiments of the present invention are not limited to the following examples, and the present invention relates to the necessary components in this technical field, which should be regarded as well-known technology in this technical field and can be known and mastered by those skilled in this technical field.

[0017] An absorbent product with a nano-soft surface layer includes a nano-soft surface layer 1, an absorbent core 2, and a leak-proof bottom layer 3. The nano-soft surface layer 1, the absorbent core 2, and the leak-proof bottom layer 3 are arranged sequentially along the thickness direction of the absorbent product. The nano-soft surface layer 1 and the leak-proof bottom layer 3 are fixedly connected to each other along the edge and together wrap the absorbent core 2 inside. The nano-soft surface layer 1 is composed of a nanofiber layer 11 and a surface non-woven fabric 12 in sequence along the thickness direction of the absorbent product. The nanofiber layer 11 is composed of a stack of nanofibers, which include the following components by mass: polyvinyl alcohol, polyethylene oxide, calcium alginate, polyvinylpyrrolidone, and sustained-release factor.

[0018] This invention discloses a technical solution for improving the comfort of sanitary products in contact with the human body through a nano-soft surface layer 1. Sanitary products that can utilize this technical solution include diapers, pull-up pants, sanitary napkins, etc. (Refer to...) Figure 1 The sanitary product is mainly composed of a nano-soft surface layer 1, an absorbent core 2, and a leak-proof bottom layer 3, which are bonded together sequentially with hot melt adhesive. The nano-soft surface layer 1 is the structural layer closest to the human body when the sanitary product is used. The nano-soft surface layer 1 comes into direct contact with the human body through a nanofiber layer 11. The nanofiber layer 11 is formed by stacking nanofibers through an electrospinning process. The nanofibers are continuously formed to create long fibers with better continuity. The size of the nanofibers is less than 1μm, which gives the nanofiber layer 11 soft and smooth properties. When the nanofiber layer 11 covers the surface of the non-woven fabric 12, the nanofiber layer 11 can isolate the protruding fiber ends on the surface of the non-woven fabric 12 from the human skin, preventing the human skin from directly contacting the surface of the non-woven fabric 12. This prevents the fiber ends that make up the non-woven fabric 12 from contacting or rubbing against the human body, avoiding the burr feeling when the user comes into contact with the nano-soft surface layer 1 during use. Furthermore, the good softness of the nanofiber layer 11 can significantly improve the comfort of the human skin when in contact with the nano-soft surface layer 1. In addition, the size of nanofibers is smaller than the texture formed by grooves and protrusions on the surface of human skin, allowing nanofibers to penetrate deep into these skin textures, increasing the fit of the nano-smooth surface layer and improving comfort. When nanofibers absorb water, swell, and release sustained-release factors, they can directly release these factors into the skin texture, achieving antibacterial and moisturizing effects by penetrating deep into the skin, thereby improving the antibacterial and moisturizing effects of the nano-smooth surface layer. It should be noted that the surface nonwoven fabric 12 is selected from either hot-air nonwoven fabric or spunlace nonwoven fabric. Both hot-air nonwoven fabric and spunlace nonwoven fabric have the characteristics of being fluffy and breathable. The main function of the surface nonwoven fabric 12 is to provide physical support and mechanical strength for the extremely thin nanofiber layer 11, so as to facilitate its bonding and fixation with the absorbent core 2 and the leak-proof bottom layer 3 in subsequent processing. In addition, there are abundant fiber gaps between the nanofibers inside the nanofiber layer 11. After the nanofiber layer 11 covers the surface of the surface nonwoven fabric 12, liquids and gases can flow through the fiber gaps inside the nanofiber layer 11 or the surface nonwoven fabric 12, thereby ensuring the breathability and moisture absorption of the nano-soft surface layer 1. Furthermore, the absorbent core 2 consists of a surface coating layer and absorbent material wrapped inside the coating layer. The coating layer is selected from one of dust-free paper and spunbond nonwoven fabric, and the absorbent material is selected from one or a mixture of two of superabsorbent resin and fluff pulp. As the internal structure of the sanitary product that absorbs and locks in liquid, the absorbent core 2 adopts a common core structure. The absorbent material is constrained and fixed inside by the coating layer. The absorbent material absorbs liquid and locks it inside by its own properties. The coating layer can ensure that the absorbent material maintains its layered structure after absorbing liquid, avoiding clumping and other phenomena inside the absorbent core 2. In addition, the absorbent core 2 can adopt a composite core structure with strong absorbency. Two layers of absorbent material are placed inside the coating layer, and the two layers of absorbent material are separated and fixed by fluffy cotton. The absorbency of the absorbent core 2 is increased by the higher amount of absorbent material. The absorbent core 2 with this composite core structure is usually set in sanitary products such as diapers and pull-ups that need to absorb a large amount of liquid. Furthermore, the leak-proof bottom layer 3 is composed of a waterproof and breathable PE membrane and an SMS non-woven fabric along the thickness direction of the absorbent product. The waterproof and breathable PE membrane is located on the side close to the absorbent core 2. The surface of the waterproof and breathable PE membrane in the leak-proof bottom layer 3 has several breathable but waterproof micropores. These micropores can ensure the breathability of the sanitary product while preventing the liquid absorbed by the absorbent core 2 from penetrating to the outer surface of the sanitary product, thus ensuring the dryness of the outer surface of the sanitary product. The SMS non-woven fabric can improve the softness of the outer surface of the sanitary product and improve the overall tensile strength of the sanitary product. Furthermore, the sustained-release factor is selected from one or more of cetrimonium bromide, nisin, nicotinamide, glycerin, hyaluronic acid, and aloe polysaccharide. Cetrimonium bromide has broad-spectrum and highly effective antibacterial activity, excellent chemical stability, and safety. Nisin has good antibacterial properties and biocompatibility. Nicotinamide, glycerin, hyaluronic acid, and aloe polysaccharide are common skin care ingredients. Since polyethylene oxide and polyvinylpyrrolidone, which are components of nanofibers, are both water-soluble, when the nanofiber layer 11 comes into contact with liquid during the use of hygiene products, the surface of the nanofibers will be slowly dissolved by the liquid and the sustained-release factor will be released. These sustained-release factors can achieve antibacterial or skin care functions when they come into contact with human skin. According to the main structure of the sanitary products of the present invention, when the sanitary products are diapers or pull-up pants, waterproof non-woven fabric and elastic spandex yarn are used to form anti-leakage side panels on both sides of the width direction of the nano-soft surface layer 1. The two ends of the sanitary products in the length direction need to be extended outward by the nano-soft surface layer 1 and SMS non-woven fabric and bonded to each other to form a waistband structure. One end of the waistband structure of the diaper is provided with elastic spandex yarn to provide elastic restraint, and it is fixed to the other end of the waistband structure by Velcro. The two ends of the pull-up pants are connected end to end to form a ring and both are provided with elastic spandex yarn. When the sanitary products are sanitary napkins, the sanitary products are cut into an oval shape and the cut edges are bonded and fixed. Adhesive is provided at the bottom of the leak-proof bottom layer 3 so that the sanitary products can be bonded to the inside of the underwear.

[0019] According to the technical solution of the present invention, the main objective is to provide an absorbent product with a smooth and soft feel on the surface in contact with the human body, which can fundamentally eliminate the burr feeling of traditional non-woven fabrics and significantly improve the comfort of use. Secondly, it provides an absorbent product surface layer with a slow-release function, which can slowly release beneficial ingredients such as antibacterial or skin care ingredients after contact with liquid. The antibacterial ingredients can prevent the growth of harmful bacteria and avoid skin itching and other problems caused by harmful bacteria. At the same time, the skin care ingredients protect the skin, keep the human skin healthy, and improve the comfort of using hygiene products. The core of this invention lies in the nano-soft surface layer 1, which adopts a composite structure and is composed of a nanofiber layer 11 and a surface nonwoven fabric 12 as a supporting substrate along the thickness direction. The nanofiber layer 11 is the key to achieving softness and functional slow release. The nanofiber layer 11 is a porous structure composed of several nano-sized ultrafine fibers stacked together. This structure is similar to that of nonwoven fabric, but the nanofibers have better fiber continuity and smaller fiber diameter, making the nanofiber layer 11 softer and smoother than common nonwoven fabrics. Among the components that make up nanofibers, polyvinyl alcohol is safe and non-toxic and has excellent fiber-forming properties. It enables the spinning solution to produce fibers with high mechanical strength during electrospinning. Furthermore, polyvinyl alcohol can be transformed into a component that is insoluble in water but still maintains a hydrophilic swelling state through thermal cross-linking and other means, so that the nano-soft layer can maintain a stable structure in a wet state. Polyethylene oxide, a common water-soluble polymer, plays a role in increasing viscosity and promoting continuous fiber formation in spinning solutions. Hydrogen bonds can be formed between the ether oxygen in the polyethylene oxide molecular chain and the hydroxyl groups of sodium alginate to increase polymer chain entanglement, enabling the spinning solution to be continuously jetted and forming nanofibers with uniform morphology and diameter. This ensures the stability of nanofibers during electrospinning. After the nanofibers are finally solidified, the presence of polyethylene oxide helps the fiber network to partially dissolve or swell when exposed to water, forming hydrophilic channels. This promotes rapid liquid penetration and provides a pathway for the release of slow-release factors. Calcium alginate is a key component derived from sodium alginate through post-processing. Calcium alginate is insoluble in water but has extremely strong hygroscopic and gel-forming abilities. It forms physical cross-linking points in nanofibers, giving nanofiber layer 11 good wet structural integrity, making nanofiber layer 11 difficult to completely dissolve and disintegrate when exposed to water. At the same time, its strong moisturizing properties help maintain a micro-humid environment inside the nano-soft surface layer 1, which is conducive to the slow release of sustained-release factors. Polyvinylpyrrolidone (PVP) is an excellent film-forming agent and excipient with good water solubility and biocompatibility. It can reduce the surface tension of spinning solutions and improve the dispersibility of slow-release factors. As one of the main components of nanofibers, PPVP assists the spinning solution in forming a film on the surface during electrospinning, encapsulating other components inside. It can also regulate the speed and uniformity of the slow dissolution of nanofibers, allowing the nanofibers to be dissolved stably and uniformly, and preventing the slow-release factors inside the nanofibers from being lost too quickly. It should be noted that in the spinning solution, the hydroxyl groups of polyvinyl alcohol can form intermolecular hydrogen bonds with the hydroxyl groups and uncrosslinked carboxyl groups on sodium alginate molecules, promoting the compatibility of the two polymers and helping to form a uniform calcium alginate network in the future. Although the hydroxyl groups of polyvinyl alcohol can also combine with calcium ions, the binding force between the two is weak and reversible. It will not consume a large number of calcium ions or destroy the crosslinked structure of calcium alginate. In addition, polyvinyl alcohol can also enhance the mechanical properties of the swollen nanofibers through hydrogen bonds, ensuring the strength of the nano-flexible layer in the wet state. This invention, through an innovative combination of materials science and electrospinning technology, designs and manufactures an absorbent product with a soft touch and slow-release functional ingredients. This technical solution, starting from the user's comfort and health needs, not only solves the problem of microscopic roughness in traditional products, but also achieves long-lasting and gentle release of functional ingredients through ingenious material design and post-processing, and has significant market competitiveness and application prospects.

[0020] A method for manufacturing an absorbent article includes the following steps: S1, the surface nonwoven fabric 12 is unwound from the nonwoven fabric roll and conveyed to the side of the electrospinning device near the receiving device. A solution containing sodium alginate is used as the spinning solution. A high voltage electric field is applied through the electrospinning device to make the spinning solution form a Taylor cone at the needle and spray out the spinning fibers. After the spinning fibers move toward the receiving device, they are stacked on the surface of the surface nonwoven fabric 12 to form a spinning fiber layer. S2, the surface nonwoven fabric 12 with the spun fiber layer formed on the surface is immediately dried to allow the solution in the spun fiber layer to evaporate and set. S3, after atomizing the calcium chloride solution, it is evenly sprayed onto the surface of the dried spinning fiber layer. Then, the non-woven fabric 12 with the spinning fiber layer is placed in a constant temperature and humidity environment and left to stand until the calcium chloride solution reacts with the spinning fiber. S4, after the spun fiber layer reacts with the calcium chloride solution, a nanofiber layer 11 is formed. The surface nonwoven fabric 12 with the nanofiber layer 11 is dried. The dried nanofiber layer 11 and the surface nonwoven fabric 12 together form a nano-soft surface layer 1. S5, after the nano-soft surface layer 1, absorbent core 2, and leak-proof bottom layer 3 are stacked, bonded and fixed in sequence, the absorbent product is obtained after cutting.

[0021] The present invention also discloses a method for manufacturing an absorbent product. In step S1 of this method, the surface nonwoven fabric 12 is processed by unwinding the rolled surface nonwoven fabric 12 and continuously conveying it to the receiving roller or plate of an electrospinning device. A spinning solution with sodium alginate as one of the main components is prepared. The spinning solution includes the following components by mass: 2%-4% polyvinyl alcohol, 2%-4% polyethylene oxide, 1%-2% sodium alginate, 4%-8% polyvinylpyrrolidone, 0.5%-1% slow-release factor, and 82%-90% water. Under the action of a high voltage electric field, the spinning solution located at the needle of the electrospinning device will form a Taylor cone. As the electric field force increases, the spinning solution at the tip of the Taylor cone is pulled out to form a continuous jet. The jet carries the same charge and is subjected to Coulomb repulsion and air resistance, resulting in high-speed stretching and moving towards the surface of the nonwoven fabric 12 near the receiving roller or plate. During the stretching process of the spinning solution forming the jet, it has a large specific surface area and is accompanied by the evaporation of some solvent, which makes the jet initially form fibers with high viscosity and adhere to the surface of the nonwoven fabric 12. It should be noted that during the electrospinning process using the electrospinning device and the spinning solution, the ambient temperature is 20-30℃, the ambient humidity is 40%-50%, the applied high-voltage electric field voltage is 15-25KV, the propulsion speed of the spinning solution is 1-2mL / h, and the distance between the needle and the surface nonwoven fabric 12 is 10-20cm. During the electrospinning process, the evaporation rate of the solvent is controlled by appropriate ambient temperature and humidity. If the humidity is too low, the evaporation is too fast and the jet fibers are prone to breakage. If the humidity is too high, the solvent evaporates slowly and the jets are prone to sticking together. Furthermore, by using appropriate voltage and receiving distance, the electric field strength is ensured to be sufficient to stretch the fibers to the sub-nanometer or even nanometer scale. Combined with an appropriate propulsion speed of the spinning solution, the Taylor cone is ensured to be stable, forming a continuous and uniform jet.

[0022] In step S2, after the jet has undergone preliminary shaping on the surface of the nonwoven fabric 12, it forms spun fibers. At this time, the spun fibers still contain a lot of solvent. Therefore, the nonwoven fabric 12 on which the spun fiber layer is formed needs to be placed in an environment of 50-60℃ and dried for 100-300s to allow some of the solvent in the spun fiber layer to evaporate, reduce the solvent content in the spun fibers, prevent structural damage or adhesion of the spun fiber layer during subsequent movement or processing, and avoid excessively low viscosity of the subsequent spinning solution after absorbing calcium chloride solution, thus ensuring the structural stability of the spun fibers.

[0023] In step S3, sodium alginate is converted into calcium alginate through an ionic crosslinking reaction. This is a key step that gives the nanofiber layer wet stability and sustained-release function. In this step, atomized calcium chloride solution is sprayed onto the surface of the spun fiber layer using a common solution atomization device. The calcium chloride solution penetrates into the interior of the spun fiber, and the calcium ions in the calcium chloride solution exchange with the sodium ions on the sodium alginate molecular chain in the spun fiber. After the reaction is completed, the spun fiber is converted into nanofiber, thereby forming a nanofiber layer on the surface of the nonwoven fabric 12. It should be noted that the nanofiber layer 11 after the reaction needs to be allowed to stand in a suitable environment. The nonwoven fabric 12 with the spun fiber layer should be placed in an environment of 30-50℃ and 100% humidity for 10-30 minutes. In this environment, the higher temperature can promote the full diffusion and penetration of calcium ions into the fiber layer, increase the reaction rate, and allow calcium chloride to fully react with sodium alginate. The high humidity environment can prevent the water in the nanofibers from evaporating outward, providing the necessary solvent environment for the ion crosslinking reaction and ensuring that the ion crosslinking reaction is carried out thoroughly. During the ion crosslinking reaction, the guluronic acid units in sodium alginate undergo egg-box model crosslinking with calcium ions to form a water-insoluble calcium alginate gel network. This process transforms the originally water-soluble sodium alginate fibers into calcium alginate fibers that only swell but do not dissolve in water. Polyethylene oxide, polyvinylpyrrolidone, and slow-release factors are interwoven in this network. It should be noted that since the molecular weight of sodium alginate increases significantly after it is converted into calcium alginate, the mass ratio of calcium alginate to other components in nanofibers is increased to some extent, based on the mass ratio of sodium alginate to other components in the spinning solution.

[0024] In step S4, the nonwoven fabric 12 with nanofiber layer 11 is dried in an environment of 50-60℃ for 0.5-2h. By drying the nanofiber layer 11 at a suitable temperature and for a sufficient time, the residual solvent in the nanofiber is completely removed. During the drying process, the diameter of the nanofiber gradually decreases, so that the nanofiber after complete drying reaches the nanoscale. At this time, the nanofiber layer 11 reaches the final stable state and obtains the required dry mechanical properties.

[0025] In step S5, the nano-soft surface layer 1, absorbent core 2, and leak-proof bottom layer 3 are sequentially stacked and bonded together. During this process, corresponding steps are added according to the type of sanitary products, such as setting leak-proof partitions on both sides of the width direction of the nano-soft surface layer 1, extending the nano-soft surface layer 1 and the bottom non-woven fabric outward along the length direction to form a waistband structure and then setting elastic spandex filaments between them, setting self-adhesive on the leak-proof bottom layer 3 and covering it with release paper, etc., thereby processing products such as diapers, pull-up pants, and sanitary napkins according to the technical solution of the present invention.

[0026] In summary, this invention discloses a sanitary product with improved comfort through a nano-soft surface layer 1 and its manufacturing method. The sanitary product mainly consists of a nano-soft surface layer 1, an absorbent core 2, and a leak-proof bottom layer 3. The nano-soft surface layer 1 is in direct contact with the human body through a nanofiber layer 11. The nanofibers, through their long fiber structure and nanoscale size, give the nanofiber layer 11 soft and smooth properties. The nanofiber layer 11 can isolate the protruding fiber ends on the surface of the non-woven fabric 12 from the human skin, avoiding direct contact between the human skin and the surface of the non-woven fabric 12. This avoids the user experiencing a rough feeling when in contact with the nano-soft surface layer 1 during use. Furthermore, the good softness of the nanofiber layer 11 can improve the comfort of the human skin when in contact with the nano-soft surface layer 1. In the manufacturing method of hygiene products, the electrospinning process is mainly based on the formation of fine spun fibers from a spinning solution containing sodium alginate under the action of a high voltage electric field, which are then attached to the surface of the nonwoven fabric 12. Subsequently, calcium chloride solution reacts with sodium alginate in the spun fibers to form calcium alginate, which gives the nanofiber layer 11 good wet structural integrity. Furthermore, after the nano-soft surface layer 1 comes into contact with water, it can release slow-release factors to achieve antibacterial and skin care functions, further improving the comfort of the hygiene products during use.

[0027] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An absorbent product with a nano-soft surface layer, comprising a nano-soft surface layer, an absorbent core, and a leak-proof bottom layer, characterized in that, The nano-soft surface layer, absorbent core, and leak-proof bottom layer are arranged sequentially along the thickness direction of the absorbent product. The nano-soft surface layer and the leak-proof bottom layer are fixedly connected to each other along the edge and together wrap the absorbent core. The nano-soft surface layer is composed of a nanofiber layer and a surface non-woven fabric in sequence along the thickness direction of the absorbent product. The nanofiber layer is composed of stacked nanofibers, which include the following components: polyvinyl alcohol, polyethylene oxide, calcium alginate, polyvinylpyrrolidone, and sustained-release factor.

2. The absorbent article with a nano-flexible surface layer according to claim 1, characterized in that, The surface nonwoven fabric is selected from either hot-air nonwoven fabric or spunlace nonwoven fabric.

3. The absorbent article with a nano-flexible surface layer according to claim 1, characterized in that, The absorbent core consists of a surface coating layer and a water-absorbing material wrapped inside the coating layer. The coating layer is selected from one of dust-free paper and spunbond nonwoven fabric, and the water-absorbing material is selected from one or a mixture of two of superabsorbent resin and fluff pulp.

4. The absorbent article with a nano-flexible surface layer according to claim 1, characterized in that, The leak-proof bottom layer is composed of a waterproof and breathable PE membrane and an SMS non-woven fabric in sequence along the thickness direction of the absorbent product, with the waterproof and breathable PE membrane located on the side close to the absorbent core.

5. The absorbent article with a nano-flexible surface layer according to claim 1, characterized in that, The sustained-release factor is selected from one or more of cetrimonium bromide, nisin, nicotinamide, glycerin, hyaluronic acid, and aloe polysaccharide.

6. A method for manufacturing an absorbent article as described in any one of claims 1-5, characterized in that, Includes the following steps: S1, the surface nonwoven fabric is unwound from the nonwoven fabric roll and conveyed to the side of the electrospinning device near the receiving device. A solution containing sodium alginate is used as the spinning solution. A high voltage electric field is applied through the electrospinning device to make the spinning solution form a Taylor cone at the needle and spray out the spinning fibers. After the spinning fibers move toward the receiving device, they are stacked on the surface of the surface nonwoven fabric to form a spinning fiber layer. S2, the surface nonwoven fabric with the spun fiber layer formed on the surface is immediately dried to allow the solution in the spun fiber layer to evaporate and set. S3, after atomizing the calcium chloride solution, it is evenly sprayed onto the surface of the dried spinning fiber layer. Then, the non-woven surface layer with the spinning fiber layer is placed in a constant temperature and humidity environment and left to stand until the calcium chloride solution reacts with the spinning fiber. S4, after the spun fiber layer reacts with the calcium chloride solution, a nanofiber layer is formed. The nonwoven fabric with the nanofiber layer is dried. The dried nanofiber layer and the nonwoven fabric together form a nano-soft surface layer. S5 is made by sequentially stacking and bonding the nano-soft surface layer, absorbent core, and leak-proof bottom layer, and then cutting it to obtain the absorbent product.

7. The method for manufacturing the absorbent article according to claim 6, characterized in that, The spinning solution comprises, by mass, the following components: 2%-4% polyvinyl alcohol, 2%-4% polyethylene oxide, 1%-2% sodium alginate, 4%-8% polyvinylpyrrolidone, 0.5%-1% sustained-release factor, and 82%-90% water.

8. The method for manufacturing the absorbent article according to claim 6, characterized in that, In step S1, during the electrospinning process using the electrospinning device through the spinning solution, the ambient temperature is 20-30℃, the ambient humidity is 40%-50%, the applied high voltage electric field is 15-25KV, the propulsion speed of the spinning solution is 1-2mL / h, and the distance between the needle and the surface nonwoven fabric is 10-20cm.

9. The method for manufacturing the absorbent article according to claim 6, characterized in that, In step S2, the nonwoven surface layer with the spun fiber layer formed on its surface is dried in an environment of 50-60℃ for 100-300s to allow some of the solvent in the spun fiber layer to evaporate. In step S4, the nonwoven fabric with the nanofiber layer is dried in an environment of 50-60℃ for 0.5-2h.

10. The method for manufacturing the absorbent article according to claim 6, characterized in that, In step S3, the nonwoven surface layer with the spun fiber layer is placed in an environment of 30-50℃ and 100% humidity for 10-30 minutes.

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