Absorption core body and hygienic product

Abstract

The invention relates to the technical field of hygienic products, and particularly discloses an absorption core and a hygienic product. The absorption core body comprises a first non-woven fabric layer, a first water-absorbent resin layer, a supporting layer, a second water-absorbent resin layer and a second non-woven fabric layer which are arranged in sequence; diversion trenches are formed in the middle areas of the first water-absorbent resin layer, the supporting layer and the second water-absorbent resin layer, and the first non-woven fabric layer and the second non-woven fabric layer penetrate through the diversion trenches to be bonded to form a bonding layer; the edges of the first non-woven fabric layer and the second non-woven fabric layer are connected in a sealing manner to form a sealing structure for packaging the first water-absorbent resin layer, the supporting layer and the second water-absorbent resin layer. Passive flow diffusion channels are provided for liquid by forming the flow guide grooves, the water-absorbent resin layers are arranged on the upper side and the lower side of the supporting layer, the residence time of the liquid on the surface layer of the absorption core body is shortened by means of the high liquid absorption response characteristic of the water-absorbent resin, and the absorption effect is improved. The technical problems that an absorption core is generally complex in structural component, poor in permeability and the like are solved.

Description

Technical Field

[0001] This application relates to the field of hygiene products technology, and in particular to an absorbent core and hygiene products. Background Technology

[0002] Currently, commercially available diapers all consist of a pant body and an absorbent core. The absorbent core is the main component of the absorbent material and can be divided into mixed cores and composite cores based on their formulation. Mixed cores are made by mixing fluff pulp with sodium polyacrylate (SAP, commonly known as absorbent beads, absorbent powder, or superabsorbent polymer), laying them out, wrapping them with toilet paper or nonwoven fabric, and bonding them with hot melt adhesive. They account for less than 10% of the market. Composite cores use multiple layers of nonwoven fabric or other materials to hold SAP, and fix the SAP using hot melt adhesive, thermal bonding, or ultrasonic bonding processes. Currently, composite cores account for over 90% of the market due to their significant performance advantages and are the mainstream technology.

[0003] The choice of SAP model directly affects core performance. Hybrid cores typically use a single SAP model, while composite cores can be combined with 1 to 4 different SAP models. Since different manufacturers and models of SAP have different performance focuses, composite cores often offer flexible performance adjustment capabilities. The current mainstream approach is to use two or more SAP layers: basic products prioritize dryness in the upper layer and high absorbency in the lower layer; upgraded products add a middle SAP layer to enhance absorption speed; high-performance products further subdivide into four SAP layers, optimizing dryness, fluid permeability, absorption speed, and absorbency respectively, to achieve a gradient performance improvement. However, existing SAP combination schemes for composite cores have significant drawbacks: First, SAP is a granular white powder, and different types of SAP laid between multiple layers of nonwoven fabric are prone to mixing on the same horizontal plane, resulting in a significant decrease in the core's absorption performance; second, multiple types of SAP need to be applied in multiple applications, and the amount applied in a single application is reduced several times, causing increased fluctuations in SAP content and leading to unstable core penetration performance; in addition, multiple types of SAP also require multiple application equipment, increasing equipment investment costs.

[0004] To further improve the performance of diapers and reduce production energy consumption, there is an urgent need to develop a new type of composite core with excellent overall performance, simple formulation, and low equipment requirements. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide an absorbent core and a sanitary product to solve the technical problems of existing absorbent cores having complex structural components and poor performance.

[0006] To achieve the above-mentioned technical objectives, this application provides an absorbent core, comprising a first nonwoven fabric layer, a first absorbent resin layer, a support layer, a second absorbent resin layer, and a second nonwoven fabric layer arranged sequentially.

[0007] The edge sealing connection of the first nonwoven fabric layer and the second nonwoven fabric layer is used to encapsulate the first absorbent resin layer, the support layer and the second absorbent resin layer; the middle regions of the first absorbent resin layer, the support layer and the second absorbent resin layer are all provided with guide grooves, and the first nonwoven fabric layer and the second nonwoven fabric layer pass through the guide grooves to bond together to form an adhesive layer.

[0008] Furthermore, at least one of the first and second absorbent resin layers comprises sodium polyacrylate, and the absorption rate of the second absorbent resin layer is greater than or equal to that of the first absorbent resin layer; in the use state, the first absorbent resin layer is located on the side of the absorbent core closer to the liquid to be absorbed.

[0009] Furthermore, the first nonwoven fabric layer is partially connected to the support layer to divide the first absorbent resin layer into a plurality of first absorbent units, and a groove is formed at the connection between the first nonwoven fabric layer and the support layer; and / or, the second nonwoven fabric layer is partially connected to the support layer to divide the second absorbent resin layer into a plurality of second absorbent units, and a groove is formed at the connection between the second nonwoven fabric layer and the support layer.

[0010] Furthermore, the first and second absorbent resin layers have the same absorption rate; both the first and second absorbent resin layers include sodium polyacrylate; in the sodium polyacrylate, the mass percentage of particles with a particle size distribution of 150~600μm or 300~810μm is ≥80%.

[0011] Furthermore, both the first and second absorbent resin layers are sodium polyacrylate; in the sodium polyacrylate, the mass percentage of particles with a particle size distribution of 280~500μm is ≥50%.

[0012] Furthermore, the absorption rate of the second absorbent resin layer is greater than that of the first absorbent resin layer; both the first and second absorbent resin layers include sodium polyacrylate; the sodium polyacrylate in the first absorbent resin layer has a particle size distribution of 150~850μm with a particle mass ratio of ≥90%; the sodium polyacrylate in the second absorbent resin layer has a particle size distribution of 150~710μm with a particle mass ratio of ≥90%.

[0013] Furthermore, both the first and second absorbent resin layers are sodium polyacrylate; in the first absorbent resin layer, the sodium polyacrylate particles with a particle size distribution of 180~850μm account for ≥90% of the mass; in the second absorbent resin layer, the sodium polyacrylate particles with a particle size distribution of 150~600μm account for ≥90% of the mass.

[0014] Furthermore, the first nonwoven layer is hydrophilic SMS nonwoven fabric, and the second nonwoven layer is hydrophilic wood pulp nonwoven fabric.

[0015] This application provides a hygiene product, including an absorbent core.

[0016] Furthermore, hygiene products include diapers, sanitary napkins, panty liners, and medical absorbent pads.

[0017] In summary, this application provides an absorbent core comprising a first nonwoven fabric layer, a first absorbent resin layer, a support layer, a second absorbent resin layer, and a second nonwoven fabric layer arranged sequentially, wherein the first nonwoven fabric layer is the absorbent side; the edges of the first and second nonwoven fabric layers are sealed together to form a sealed structure encapsulating the first absorbent resin layer, the support layer, and the second absorbent resin layer; a guide groove is provided in the middle region of the first absorbent resin layer, the support layer, and the second absorbent resin layer, and the first and second nonwoven fabric layers pass through the guide groove and are bonded together to form an adhesive layer. This application creates a flow channel between the absorbent resin layer and the support layer to provide a passive flow diffusion channel for the liquid at the moment of contact with the absorbent core. This enhances the diffusion length and area of ​​the liquid inside the core, reduces the liquid absorption load per unit area of ​​the absorbent resin layer, and thus ensures that the absorbent core has an extremely low liquid backflow, effectively improving dryness during use. This application also arranges absorbent resin layers on the upper and lower sides of the support layer. By utilizing the high liquid absorption response characteristics of the absorbent resin itself and the mutual cooperation between the absorbent resins, the locking speed of the liquid in the core is further accelerated, and the residence time of the liquid on the surface of the core is shortened.

[0018] Compared with existing technologies, the absorber core proposed in this application has comprehensive advantages such as simple structure and excellent performance: its permeability is better than that of commercially available single-structure cores, and its structural complexity is lower than that of existing complex structure cores, successfully solving the technical problems of complex structural composition and poor performance that are common in current absorber cores. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a cross-sectional schematic diagram of an absorber core provided in an embodiment of this application;

[0021] Figure 2 An absorbent core is provided for an embodiment of this application; wherein, (a) is a top view of the absorbent core, and (b) is a physical image of the absorbent core;

[0022] Figure 3 This is a cross-sectional schematic diagram of an absorbent core provided in an embodiment of this application; wherein the first absorbent resin layer and the second absorbent resin layer are both filled with the same type of sodium polyacrylate;

[0023] Figure 4 This is a cross-sectional schematic diagram of an absorbent core provided in an embodiment of this application; wherein the first absorbent resin layer and the second absorbent resin layer are filled with different types of sodium polyacrylate;

[0024] Figure 5 A cross-sectional schematic diagram of an absorber core provided in Comparative Example 1 of this application;

[0025] Figure 6 This is a cross-sectional schematic diagram of an absorber core provided in Comparative Example 2 of this application;

[0026] Figure 7 This is a cross-sectional schematic diagram of an absorber core provided in Comparative Example 3 of this application;

[0027] Figure 8 This is a cross-sectional schematic diagram of an absorber core provided in Comparative Example 4 of this application;

[0028] Figure 9 This is a schematic diagram illustrating the liquid absorption capacity of an absorbent core provided in an embodiment. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.

[0030] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] The sodium polyacrylate involved in this invention is all in white granular form, and its specific performance parameters are detailed in Table 1. It should be noted that the SAP models in Tables 1 and 2 are abbreviations, and their specific manufacturers and complete model correspondences are as follows: Sumitomo SA60S (Sumitomo Chemical, Japan, SA60S); Catalyst W101 (China Catalyst New Materials Co., Ltd., W101); Catalyst W2086 (China Catalyst New Materials Co., Ltd., W2086); BASF N7059 (BASF, Germany, N7059); BASF T3763 (BASF, Germany, T3763); Sansai N158 (Sansai Chemical, Japan, N158); Sansai IM-930C (Sansai Chemical, Japan, IM-930C); Noor NR-610S (Shandong Noor Biotechnology Co., Ltd., NR-610S); Formosa Plastics BC8001 (Taiwan Plastics Industry Co., Ltd., BC8001); LG GS-810ND (LG Chem, South Korea, GS-810ND). The performance parameters disclosed in Table 1 were obtained according to the national standard GB / T22875-2018 "Superabsorbent Resins for Diapers and Sanitary Napkins". Other raw materials involved in this invention are not particularly limited in their source and can be purchased commercially or prepared using conventional methods well known to those skilled in the art.

[0033] Table 1. Types and performance parameters of water-absorbing resins

[0034]

[0035] See Figure 1 This application provides an absorbent core, comprising a first nonwoven fabric layer, a first absorbent resin layer, a support layer, a second absorbent resin layer, and a second nonwoven fabric layer arranged sequentially.

[0036] The edge sealing connection of the first nonwoven fabric layer and the second nonwoven fabric layer is used to encapsulate the first absorbent resin layer, the support layer and the second absorbent resin layer; the middle regions of the first absorbent resin layer, the support layer and the second absorbent resin layer are all provided with guide grooves, and the first nonwoven fabric layer and the second nonwoven fabric layer pass through the guide grooves to bond together to form an adhesive layer.

[0037] It should be noted that the absorbent core provided in this application does not have a covering cloth on its surface, which effectively reduces the flow resistance of liquid on the surface of the absorbent core and significantly improves the absorption speed of the absorbent core. Regarding the structure of the absorbent core, the guide groove opened between the first absorbent resin layer, the support layer, and the second absorbent resin layer can quickly guide the liquid, while the support layer (especially fluffy cotton) can provide a passive flow diffusion channel for the liquid at the moment of contact with the absorbent core.

[0038] In some embodiments, the mass ratio of the first absorbent resin layer and the second absorbent resin layer is 1:1, and at least one of the first absorbent resin layer and the second absorbent resin layer includes sodium polyacrylate, the particle size of which is 105~850μm; the absorption rate of the second absorbent resin layer is greater than or equal to that of the first absorbent resin layer; and in the use state, the first absorbent resin layer is closer to the side of the liquid to be absorbed.

[0039] It should be noted that when the absorption rate of the second absorbent resin layer is greater than that of the first absorbent resin layer, this setting can create a gradient absorption effect by taking advantage of the difference in absorption rates between the second and first absorbent resin layers, accelerating the flow of liquid from the first absorbent resin layer to the second absorbent resin layer and enhancing the absorption rate of the liquid; it can also prevent liquid from seeping back from the second absorbent resin layer to the first absorbent resin layer, which can effectively improve the dryness of the first nonwoven fabric layer.

[0040] It should be noted that this application uses sodium polyacrylate, a water-absorbing resin particle with fast absorption speed and small particle size. Through the material's high liquid absorption response characteristics, the liquid locking speed of the absorbent core can be further improved, and the residence time of the liquid on the surface of the absorbent core can be reduced.

[0041] In some embodiments, a guide groove is formed in the middle region of the first absorbent resin layer, the second absorbent resin layer, and the support layer, overlapping along the thickness direction of the absorbent core. More specifically, the guide groove has a length of 150~250mm and a width of 10~20mm.

[0042] In some preferred embodiments, a flow channel is provided in the middle region of the first absorbent resin layer, the support layer, and the second absorbent resin layer of the absorbent core; along the thickness direction of the absorbent core (i.e., from the first absorbent resin layer through the support layer to the second absorbent resin layer), the size of each flow channel decreases sequentially, and the central axis of each flow channel coincides with the axis of the absorbent core in the thickness direction, forming a stepped flow channel that runs through the axis.

[0043] In some preferred embodiments, the size of the channeling groove on the second absorbent resin layer is half the size of the channeling groove on the first absorbent resin layer. This stepped size design not only guides the liquid to quickly penetrate downwards through the nonwoven fabric layer, but also strengthens the contact channels between the second absorbent resin layer and the liquid by utilizing the small-sized channeling groove of the second absorbent resin layer, thereby improving the liquid capture and absorption efficiency of the second absorbent resin. Furthermore, combined with the characteristic that the absorption rate of the second absorbent resin layer is greater than or equal to that of the first absorbent resin layer, it also prevents liquid from seeping back from the second absorbent resin layer to the first absorbent resin layer, effectively improving the dryness of the first nonwoven fabric layer. In addition, this stepped size design can also avoid the problem of reduced local structural strength of the absorbent core due to excessively large channeling grooves, ensuring the structural integrity of the absorbent core during long-term use.

[0044] In some embodiments, a first nonwoven fabric layer and a second nonwoven fabric layer, corresponding to the position of the guide groove along the thickness direction of the absorbent core, pass through the guide groove and are bonded together to form an adhesive layer; at least one of the first nonwoven fabric layer, the second nonwoven fabric layer and the adhesive layer is fixedly connected to the support layer, completely separating the first absorbent resin layer and the second absorbent resin layer, preventing the sodium polyacrylate in the first / second absorbent resin layers from shifting or leaking into each other.

[0045] In a preferred embodiment, the adhesive layer has neither a support layer nor absorbent resin (such as sodium polyacrylate) filling, and its thickness is measured to be ≤1mm, while the thickness of the support layer is approximately 2~3mm. Test results show that the support layer with a guide channel in the central region can significantly improve the first absorption rate, the second absorption rate, and the liquid diffusion length of the absorbent core, while significantly reducing the amount of backflow, demonstrating a clear optimization effect in technical performance.

[0046] In some preferred embodiments, the guide groove is arranged laterally at the center line of the absorber core and longitudinally at one end near the length of the absorber core.

[0047] It should be noted that after a user wears a diaper with this absorbent core, the channel precisely covers the typical urination points of the human body (such as adults or infants). This creates a passive flow channel when the channel comes into contact with liquid, rapidly guiding the liquid into the channel and significantly reducing the liquid's residence time on the surface of the absorbent core. Because the channel is appropriately sized, urine can quickly gather in it. Simultaneously, the support layer allows the liquid to rapidly diffuse within the three-dimensional space of the absorbent core, significantly improving diffusion efficiency. Furthermore, the support layer promotes rapid contact between the first and second absorbent resin layers, further enhancing absorption and achieving highly efficient absorption in three dimensions, thus increasing overall absorption speed. When the liquid diffuses within the three-dimensional space of the absorbent core, the absorption rate of the first absorbent resin layer is lower than that of the second absorbent resin layer. Therefore, the second absorbent resin layer often absorbs more liquid than the first, greatly reducing backflow and maintaining the dryness of the first non-woven fabric layer.

[0048] In some specific embodiments, taking the urine absorption scenario as an example, when the user urinates, the diversion channels in the absorbent core can achieve the directional and rapid diversion of urine, efficiently transporting the vast majority of urine from the first non-woven fabric layer towards the second non-woven fabric layer, significantly reducing the urine residue on the surface of the first non-woven fabric layer; the support layer rapidly diffuses the urine in the diversion channels to the surrounding areas through its three-dimensional through-structure, enabling the urine to simultaneously contact the first superabsorbent resin layer and the second superabsorbent resin layer and be synergistically absorbed by both. Since the second superabsorbent resin layer has a better liquid absorption rate characteristic, the main body of the urine is preferentially captured and locked by the second superabsorbent resin layer, and only a small amount of urine is absorbed by the first superabsorbent resin layer. Therefore, urine backflow to the first non-woven fabric layer can be effectively blocked to ensure the dryness of the surface of the absorbent core during use. In addition, the support layer can also provide stable structural support for the rapid liquid absorption and liquid locking of the double-layer superabsorbent resin layer, accelerating the overall distribution of urine within the core, and thus significantly improving the overall liquid absorption efficiency of the absorbent core.

[0049] In some embodiments, the first non-woven fabric layer and the support layer are partially connected to separate the first superabsorbent resin layer into first absorption units, and a groove is formed at the connection between the first non-woven fabric layer and the support layer; and / or, the second non-woven fabric layer and the support layer are partially connected to separate the second superabsorbent resin layer into multiple second absorption units, and a groove is formed at the connection between the second non-woven fabric layer and the support layer.

[0050] It should be noted that the top view and the physical diagram of the absorbent core provided in this embodiment are shown in (a) and Figure 2 (b) in Figure 2 respectively. As can be Figure 2 seen, the non-woven fabric layer and the support layer of the absorbent core separate the superabsorbent resin layer into multiple independent and matrix-distributed absorption units through partial connection, and the absorption units are arranged in a matrix; at the same time, the connection areas between the non-woven fabric layer and the support layer form grooves distributed in a "field" shape, and these grooves have multiple functions: firstly, they can serve as diversion channels to accelerate liquid diffusion and improve the liquid diffusion efficiency of the core; secondly, they can reduce the contact area between the absorbent core and the skin, thereby enhancing the dryness and comfort during use; thirdly, they can form a containment space for baby loose stools, reducing the direct contact between the loose stools and the skin and reducing the discomfort during use.

[0051] In some preferred embodiments, the support layer is a fluffy cotton made from ES fibers and PET fibers.

[0052] It should be noted that the material design of the absorbent core uses a blend of ES and PET fibers. This ensures the bonding strength of the absorbent core itself and between it and other layers (the first and second non-woven fabric layers), while also providing ample space for resin expansion. This gives the absorbent core a certain degree of elongation, meaning that even if the sodium polyacrylate expands due to liquid absorption during actual use, the bond between the absorbent core and the absorbent resin layer will not crack due to expansion stress. Furthermore, it maintains the high loft of the absorbent core, forming a dimensionally appropriate void structure that allows for uniform filling of the sodium polyacrylate while restricting its displacement within the voids.

[0053] In some embodiments, the first and second absorbent resin layers have the same absorption rate; both the first and second absorbent resin layers comprise sodium polyacrylate, and the mass percentage of particles with a particle size distribution of 150~600μm or 300~810μm in the sodium polyacrylate is ≥80%. More specifically, the first and second absorbent resin layers may be sodium polyacrylate of the same brand and model, and the sodium polyacrylate may be at least one of Sumitomo SA60S, Catalyst W101, Catalyst W2086, BASF N7059, BASF T3763, Sanya N158, Sanya IM-930C, Noor NR-610S, Formosa Plastics BC8001, and LG GS-810ND.

[0054] In some embodiments, the first and second absorbent resin layers are sodium polyacrylate; the mass percentage of particles with a particle size distribution of 280~500μm in the sodium polyacrylate is ≥50%. More specifically, both the first and second absorbent resin layers are sodium polyacrylate of the same brand and model, such as BASF T3763, Sanya IM-930C, Noor NR-610S, or Formosa Plastics BC8001.

[0055] It should be noted that for absorbent cores using the same type of sodium polyacrylate, sodium polyacrylate with both a fast liquid absorption rate and a low reabsorption rate should be selected. Preferably, the sodium polyacrylate has a concentrated particle size distribution and a medium range of particle size homogeneity, so as to achieve synergistic optimization of liquid absorption performance and liquid retention performance.

[0056] In some embodiments, the absorption rate of the second absorbent resin layer is greater than that of the first absorbent resin layer; both the first and second absorbent resin layers comprise sodium polyacrylate; in some preferred embodiments, the average particle size of the sodium polyacrylate in the first absorbent resin layer is larger than that in the second absorbent resin layer, and the absorption time of the sodium polyacrylate in the first absorbent resin layer is greater than that in the second absorbent resin layer. It should be noted that the larger the absorption rate value in Table 1, the longer the absorption time and the slower the absorption rate. Furthermore, in the first absorbent resin layer, the sodium polyacrylate particles with a particle size distribution of 150~850μm account for ≥90% of the mass, and the absorption rate is 35~60s; in the second absorbent resin layer, the sodium polyacrylate particles with a particle size distribution of 150~710μm account for ≥90% of the mass, and the absorption rate is 30~45s. Taking the models and performance parameters of the absorbent resins shown in Table 1 as an example: the sodium polyacrylate in the first absorbent resin layer is at least one of Catalyst W101, Catalyst W2086, BASF N7059, BASF T3763, Sanya N158, Sanya IM-930C, Noir NR-610S, Formosa Plastics BC8001, and LG GS-810ND. Of course, other absorbent resins with similar characteristics can also be used instead. The sodium polyacrylate in the second absorbent resin layer is at least one of Sumitomo SA60S, Sanya N158, Sanya IM-930C, and Noir NR-610S. Of course, other absorbent resins with similar characteristics can also be used instead.

[0057] In some preferred embodiments, the first and second absorbent resin layers are sodium polyacrylate. Preferably, the particle size of the sodium polyacrylate in the first absorbent resin layer is 1.2 to 8 times that of the second absorbent resin layer, and the absorption time of the sodium polyacrylate in the second absorbent resin layer is 0.35 to 0.85 times that of the first absorbent resin layer. Furthermore, the sodium polyacrylate in the first absorbent resin layer has a particle size distribution of 180-800 μm with a particle size ratio of ≥90% by mass; and a centrifugal water retention capacity of ≥35 g / g. The sodium polyacrylate in the second absorbent resin layer has a particle size distribution of 150-600 μm with a particle size ratio of ≥90% by mass. Taking the absorbent resin types and performance parameters shown in Table 1 as examples: the sodium polyacrylate in the first absorbent resin layer includes at least one of Catalyst W101, BASF T3763, and Sanya N158; the sodium polyacrylate in the second absorbent resin layer includes at least one of Sumitomo SA60S and Noor NR-610S.

[0058] In some preferred embodiments, the sodium polyacrylate in the first absorbent resin layer has a particle size distribution of 180-800 μm, with a particle size distribution of 300-600 μm accounting for ≥60% of the total mass, and a centrifugal water retention of ≥35 g / g; the sodium polyacrylate in the second absorbent resin layer has a particle size distribution of 180-500 μm, with a particle size distribution of ≥90% of the total mass. Taking the absorbent resin types and performance parameters shown in Table 1 as examples: the sodium polyacrylate in the first absorbent resin layer includes at least one of BASF T3763 and Sanya N158, and the sodium polyacrylate in the second absorbent resin layer includes Sumitomo SA60S.

[0059] It should be noted that for sodium polyacrylate with a concentrated particle size distribution and relatively small overall size, such as particles with a particle size range of 150μm~500μm accounting for ≥90% of the mass, its liquid absorption rate is relatively fast, but the liquid re-permeation is relatively high, making it suitable for the lower layer structure of the absorbent core (such as the second water-absorbing resin layer).

[0060] In some embodiments, the first nonwoven layer is hydrophilic SMS nonwoven fabric, and the second nonwoven layer is hydrophilic wood pulp nonwoven fabric.

[0061] It should be noted that the first nonwoven layer using hydrophilic SMS nonwoven fabric has the following advantages: First, its hydrophilic properties quickly guide liquid to the lower layer of the absorbent core, effectively reducing the amount of liquid accumulation on the surface of the absorbent core and improving dryness during use; second, its own fiber structure forms a physical barrier to prevent sodium polyacrylate leakage; third, it can be firmly bonded to the fluffy cotton using hot melt adhesive, improving peel strength. The second nonwoven layer using hydrophilic PP wood pulp nonwoven fabric has the following advantages: First, it forms a high peel strength adhesive structure with the fluffy cotton, strengthening the stability of the core structure; second, the fluffy nature of the wood pulp fibers wraps and buffers the sharp edges of the sodium polyacrylate, reducing the risk of the sodium polyacrylate puncturing the PE leak-proof membrane due to its sharp edges, thus avoiding leakage problems.

[0062] This application provides a hygiene product, including an absorbent core.

[0063] In some embodiments, hygiene products include diapers, sanitary napkins, panty liners, and medical absorbent pads.

[0064] In some specific embodiments, the hygiene product is a diaper, which consists of a pant body and an absorbent core. The pant body includes a three-dimensional anti-leakage guard, a top layer, an anti-leakage PE film, a bottom layer, and left and right ear flaps, an elastic waistband, and leg elastics disposed between the top layer and the bottom layer. The components are fixedly connected by hot melt adhesive or hot pressing to form a pant body structure with wearable function. The three-dimensional anti-leakage guard is symmetrically arranged on both sides of the top layer along the length of the pant body, the elastic waistband is fixed circumferentially along the top of the pant body, and the leg elastics are fixed circumferentially along the bottom leg openings of the pant body to achieve a close fit to the human body for leak prevention and wearing stability. The absorbent core is disposed between the top layer of the pant body and the anti-leakage PE film.

[0065] The applicant further provides the following specific embodiments to describe the present invention. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0066] Example 1

[0067] This embodiment provides an absorbent core, comprising a first nonwoven fabric layer, a first absorbent resin layer (SAP1), a support layer (fluffy cotton layer), a second absorbent resin layer (SAP2), and a second nonwoven fabric layer arranged sequentially. The edges of the first and second nonwoven fabric layers are sealed together to encapsulate the first absorbent resin layer, the support layer, and the second absorbent resin layer. A guide groove is formed in the middle region of the first absorbent resin layer, the support layer, and the second absorbent resin layer. Along the thickness direction of the absorbent core (i.e., from the first absorbent resin layer through the support layer to the second absorbent resin layer), the size of each guide groove decreases sequentially, and the central axis of each guide groove coincides with the axis of the absorbent core in the thickness direction, forming a stepped guide channel that runs through the axis. The size of the guide groove on the second absorbent resin layer is 1 / 2 the size of the guide groove on the first absorbent resin layer. The first and second nonwoven fabric layers pass through the guide grooves and are bonded together with hot melt adhesive to form an adhesive layer.

[0068] The first nonwoven fabric layer is partially connected to the support layer to divide the first absorbent resin layer into first absorbent units, and a groove is formed at the connection between the first nonwoven fabric layer and the support layer; the second nonwoven fabric layer is partially connected to the support layer to divide the second absorbent resin layer into multiple second absorbent units, and a groove is formed at the connection between the second nonwoven fabric layer and the support layer. In use, the first absorbent resin layer is positioned closer to the liquid to be absorbed.

[0069] The first nonwoven layer is a 15gsm hydrophilic SMS nonwoven fabric with a thickness of 0.12~0.18mm, preferably about 0.15mm (0.15mm in this embodiment); the second nonwoven layer is a 50gsm hydrophilic PP wood pulp nonwoven fabric with a thickness of 0.6~0.68mm, preferably about 0.64mm (0.64mm in this embodiment); SAP1 and SAP2 can be sodium polyacrylate of the same or different brands and models, as shown in Table 1; the fluffy cotton is formed by processing ES fiber and PET fiber, and has a porous, hollow shape with a thickness of 2.5~3mm. A square guide channel is also provided in the middle area of ​​the fluffy cotton, with a length of 150±0.3mm and a width of 10±0.1mm (see Table 1). Figure 2 The thickness of the adhesive layer is approximately 1 ± 0.05 mm.

[0070] Examples 2 to 22

[0071] Examples 2 to 22 all provide an absorber core. The difference from Example 1 is that SAP1 and SAP2 use different materials, as shown in Table 1.

[0072] Because the materials used in SAP1 and SAP2 in the embodiments are different, the absorber core structures in embodiments 1-10 can be found in [reference needed]. Figure 3 The absorption core structures of Examples 11-22 are shown below. Figure 4 .

[0073] Comparative Example 1

[0074] This comparative example provides an absorbent core, which consists of a filling layer and a wrapping layer. The specific structure is described in reference [reference needed]. Figure 5 The filling layer is made by mixing SAP (BASF 7059) and fluff pulp in a 1:1 mass ratio; the wrapping layer is made of 20gsm wet strength paper wrapped with cloth to completely wrap the filling layer.

[0075] Comparative Example 2

[0076] This comparative example provides an absorbent core, which consists of a filling layer and a wrapping layer. See details of the structure below. Figure 6 The filling layer includes 50gsm cleanroom paper, absorbent resin, and 50gsm cleanroom paper arranged sequentially from top to bottom; wherein, the absorbent resin is formed by mixing SAP1 (BASF 7059) and SAP2 (Sumitomo SA60S); the wrapping layer is a hydrophilic 15gsm SSS wrapping cloth, which completely wraps the filling layer.

[0077] Comparative Example 3

[0078] See Figure 5This comparative example provides an absorbent core, which consists of a filling layer and a wrapping layer. For details of the specific structure, please refer to [link / reference]. Figure 7 The filling layer consists of, from top to bottom, hydrophilic 15gsm SMS nonwoven fabric, absorbent resin (specifically SAP1 BASF 7059), regular fluffy cotton, absorbent resin (SAP2 Sumitomo SA60S), and 50gsm cleanroom paper; the wrapping layer is hydrophilic 15gsm SSS nonwoven fabric, and the hydrophilic 15gsm SSS nonwoven fabric partially wraps the filling layer.

[0079] Comparative Example 4

[0080] This comparative example provides an absorbent core, which consists of a filling layer and a wrapping layer. See details of the structure below. Figure 8 The filling layer comprises, from top to bottom, a hydrophilic 15gsm SMS nonwoven fabric, absorbent resin (a mixture of SAP1 BASF 7059 and SAP2 catalyst W101), regular fluffy cotton, absorbent resin (a mixture of SAP3 catalyst W2086 and SAP2 Sumitomo SA60S), and a hydrophilic 50gsm PP wood pulp nonwoven fabric. The absorbent resin has multiple channeling grooves arranged along the thickness direction of the absorbent core. The wrapping layer is a hydrophilic 8gsm PP wood pulp nonwoven fabric, which partially wraps the filling layer.

[0081] Testing: To evaluate the basic functions of the absorbent core, the absorption rate and reabsorption volume of the absorbent cores provided in each embodiment were tested in accordance with GB / T28004.1 standard. The test results are shown in Table 2. At the same time, to more comprehensively highlight the advantages of the embodiments, tests related to leakage volume, diffusion length and user experience were added for Embodiment 4, Embodiment 16 and the comparative example. The specific results are shown in Table 3.

[0082] Table 2. SAP models and performance parameters of absorber cores

[0083]

[0084] As shown in Table 2, the absorbent core prepared in this embodiment meets all performance indicators of the technical requirements for baby diapers, baby diaper pads, and baby diaper mats (nursing pads) in Chapter 5.1 of GB / T28004.1-2021 "Diapers Part 1: Baby Diapers". The test results show that the overall performance of each embodiment is excellent, and the test data of several embodiments show a significant improvement over the standard requirements, as detailed below:

[0085] (1) Test results for SAP1 and SAP2 using the same absorbent resin: An increase in absorption rate is usually accompanied by an increase in backflow, while a decrease in backflow corresponds to a slowdown in absorption rate. This characteristic makes it difficult for existing technologies to achieve a comprehensive improvement in both absorption rate and backflow prevention effect. A compromise value is often selected between the two core performance indicators of "absorption rate" and "backflow" to balance performance. However, the absorbent core provided in this application is superior to existing technologies in both "absorption rate" and "backflow prevention" indicators. In particular, the experimental data of Examples 5, 6, 7, and 9 show that the absorbent core provided in this application can specifically enhance another key performance (such as anti-backflow effect) while maintaining the stability of a certain core performance (such as permeation rate), ultimately achieving a synergistic balance between "permeation rate and anti-backflow effect".

[0086] (2) Test results for SAP1 and SAP2 with different absorbent resins: When SAP1 and SAP2 are different types of absorbent resins, the permeation rates of Examples 11 and 17 are in the middle range of Examples 11 to 22, but their anti-backflow performance has achieved a breakthrough improvement. This phenomenon indicates that the formulation system used in Examples 11 and 17 can significantly optimize the anti-backflow ability of the core while ensuring the basic permeation efficiency. In addition, Example 18 also effectively improved the permeation rate of the core while controlling the backflow amount within a specific range.

[0087] Table 3. SAP models, structures, and performance parameters of the absorber core

[0088]

[0089] According to the data in Table 3,

[0090] (1) Performance analysis of Comparative Examples 1 and 2: The permeation rate of conventional single-layer superabsorbent resins failed to be significantly improved, and the reabsorption rate remained at a high level. This result indicates that the existing single-layer structure and simple superabsorbent resin blending methods are insufficient to overcome the performance bottleneck of "low permeation rate and high reabsorption rate".

[0091] (2) Performance analysis of Comparative Example 3 and Example 17: The core technical difference between Example 17 and Comparative Example 3 lies in the core structure design: Example 17 adds a guide channel structure in the middle of the fluffy cotton and absorbent resin layer, and divides the absorbent resin layer into multiple independent and matrix-distributed absorption units through the local connection between the non-woven fabric layer and the support layer; Comparative Example 3 uses conventional fluffy cotton without the above-mentioned structural optimization. Performance test results show that the permeation rate and anti-backflow performance of Example 17 are significantly better than those of Comparative Example 3. This comparison result confirms that the fluffy cotton with guide channels and the matrix absorption area designed in this application can effectively improve the overall performance of the core.

[0092] (3) Performance analysis of Comparative Example 4 and Example 4: Comparison of the test data of Comparative Example 4 and Example 4 revealed that: Comparative Example 4 adopts a multi-layer water-absorbing resin structure, and each layer is compounded with multiple components, and multiple grooves for flow guidance are opened on the water-absorbing resin layer. However, it is only slightly better than Example 4 in terms of permeation rate. Its anti-backflow performance and other key performance indicators are significantly lower than the absorbent core provided by Example 4 of this application. Furthermore, Example 4 is not the best embodiment in terms of overall performance in this application. The performance indicators of Examples 5 and 17 of this application are all better than those of Example 4. It can be seen that the absorbent core obtained by this application through specific structural design and water-absorbing resin combination has a comprehensive performance far exceeding the prior art (Comparative Example 4).

[0093] In summary, the absorbent core provided in this application has superior overall performance compared to conventional absorbent cores with simpler structures. Compared to absorbent cores with more complex compositions and structures, the absorbent core provided in this application can selectively enhance another key performance (such as anti-backflow effect) while maintaining the stability of a certain core performance (such as permeation rate). Ultimately, it achieves a synergistic balance between "permeation rate and anti-backflow effect" by using a more streamlined structure and composition combination.

[0094] The above are merely preferred embodiments of this application and are not intended to limit the present invention. Although this application has been described in detail with reference to examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An absorbent core, characterized in that, The first non-woven fabric layer, the first water-absorbing resin layer, the support layer, the second water-absorbing resin layer, and the second non-woven fabric layer are sequentially arranged. The edges of the first non-woven fabric layer and the second non-woven fabric layer are sealingly connected to encapsulate the first water-absorbing resin layer, the support layer, and the second water-absorbing resin layer. The middle regions of the first water-absorbing resin layer, the support layer, and the second water-absorbing resin layer are each provided with a flow guide groove, and the first non-woven fabric layer and the second non-woven fabric layer pass through the flow guide groove to form a bonding layer.

2. The absorbent core according to claim 1, wherein: At least one of the first water-absorbing resin layer and the second water-absorbing resin layer comprises sodium polyacrylate, and the absorption speed of the second water-absorbing resin layer is greater than or equal to that of the first water-absorbing resin layer; In the use state, the first water-absorbing resin layer is close to the side of the liquid to be absorbed.

3. The absorbent core according to claim 2, wherein: The first non-woven fabric layer is partially connected with the support layer to divide the first water-absorbing resin layer into a plurality of first absorption units, and the connection between the first non-woven fabric layer and the support layer forms a groove. And / or, the second non-woven fabric layer is partially connected with the support layer to divide the second water-absorbing resin layer into a plurality of second absorption units.

4. The absorbent core according to claim 2, wherein: The absorption speeds of the first water-absorbing resin layer and the second water-absorbing resin layer are the same. Both the first water-absorbing resin layer and the second water-absorbing resin layer comprise sodium polyacrylate, and the mass percentage of the particles with a particle size distribution of 150-600 μm or 300-810 μm in the sodium polyacrylate is ≥80%.

5. The absorbent core according to claim 4, wherein: Both the first water-absorbing resin layer and the second water-absorbing resin layer are sodium polyacrylate, and the mass percentage of the particles with a particle size distribution of 280-500 μm in the sodium polyacrylate is ≥50%.

6. The absorbent core according to claim 2, wherein: The absorption speed of the second water-absorbing resin layer is greater than that of the first water-absorbing resin layer. Both the first water-absorbing resin layer and the second water-absorbing resin layer comprise sodium polyacrylate, the mass percentage of the particles with a particle size distribution of 150-850 μm in the sodium polyacrylate in the first water-absorbing resin layer is ≥90%, and the mass percentage of the particles with a particle size distribution of 150-710 μm in the sodium polyacrylate in the second water-absorbing resin layer is ≥90%.

7. The absorbent core according to claim 6, wherein: Both the first water-absorbing resin layer and the second water-absorbing resin layer are sodium polyacrylate, the mass percentage of the particles with a particle size distribution of 180-850 μm in the sodium polyacrylate in the first water-absorbing resin layer is ≥90%, and the mass percentage of the particles with a particle size distribution of 150-600 μm in the sodium polyacrylate in the second water-absorbing resin layer is ≥90%.

8. The absorbent core according to claim 2, wherein: The first non-woven fabric layer is a hydrophilic SMS non-woven fabric, and the second non-woven fabric layer is a hydrophilic wood pulp non-woven fabric.

9. A sanitary article, characterized in that: The absorbent core comprises any one of the absorbent cores according to claims 1-8.

10. The sanitary article according to claim 9, characterized in that The sanitary products include paper diapers, sanitary napkins, panty liners and medical liquid absorbing pads.

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