An absorbent core and an absorbent article

Abstract

An absorbent core includes: a first absorbent core layer comprising at least two fiber layers and a polymer absorbent layer disposed between the fiber layers; a second absorbent core layer composited on top of the first absorbent core layer, and the second absorbent core layer comprising a mixture absorbent layer of pulverized wood pulp and polymer absorbent material; and a covering layer covering the first and second absorbent core layers to form an integrated structure. The absorbent core, through its upper and lower double-layer composite structure combined with the outer covering layer, rapidly captures and initially absorbs liquid through the wood pulp-polymer absorbent layer of the upper second absorbent core layer. The liquid then flows downwards through the multiple fiber layers and polymer absorbent layers of the first absorbent core layer, where it is rapidly guided and deeply stabilized for water retention, thus achieving rapid absorption.

Description

Technical Field

[0001] This application relates to the technical field of hygiene products, specifically to an absorbent core and absorbent article. Background Technology

[0002] Commonly used wearable absorbent products generally include overnight pants, disposable underwear, baby pull-ups, and adult diapers. These products need to come into direct contact with the human body and are essential care products for incontinent individuals. Their core function is to quickly absorb and lock in liquid, keeping the user's skin dry and preventing leakage. The absorbent core is a key component that determines the performance of a diaper, and it is generally located between the top and bottom layers.

[0003] Currently, adult diaper absorbent cores on the market are mainly divided into two types: The first type is a traditional wood pulp fluff pulp mixed with superabsorbent polymer (SAP) core. This type of core is prone to clumping and tearing after absorption, and it is easily compacted under heavy pressure (such as when the user is lying down), leading to blockage and leakage of the absorbent channels. At the same time, in order to ensure absorbency, its thickness is often relatively large, affecting wearing comfort. The second type is an ultra-thin composite core made of materials such as dust-free paper and non-woven fabric bonded with SAP through hot melt adhesive. Although the thickness is reduced, it generally has problems such as slow instantaneous flow rate and poor repeated liquid absorption capacity due to the uniform distribution of SAP, and it is still prone to leakage under large urine volume impacts. Utility Model Content

[0004] This application provides an absorbent core and an absorbent article to improve absorption efficiency.

[0005] According to one aspect of this application, one embodiment provides an absorbent core, comprising:

[0006] The first absorbent core layer includes at least two fiber layers and a polymer absorbent layer disposed between the fiber layers;

[0007] The second absorbent core layer is composited on top of the first absorbent core layer, and the second absorbent core layer comprises a mixture of pulverized wood pulp and polymer absorbent material.

[0008] And a coating layer, which covers the first and second absorbent core layers to form an integral structure.

[0009] In another embodiment, the first absorbent core layer is irregularly shaped, the second absorbent core layer is rectangular, and the second absorbent core layer is located within the projection range of the second absorbent core layer on the plane.

[0010] In another embodiment, the first absorbent core layer includes a front section, a middle section, and a rear section in the length direction, wherein the front section and the rear section are wider than the middle section, and the outer contours of the front section and the rear section are arc-shaped.

[0011] In another embodiment, the width of the rear segment is greater than the width of the front segment.

[0012] In another embodiment, the front segment and the rear segment are symmetrically arranged about the middle segment.

[0013] In another embodiment, the multilayer fiber layer includes an absorbent surface layer and an absorbent bottom layer disposed from top to bottom, and the absorbent surface layer is provided with at least one layer, with the polymer absorbent layer sandwiched between any two fiber layers.

[0014] In another embodiment, the absorbent surface layer is made of dust-free paper, which is made by mixing wood pulp with chemical fibers and then reinforcing the mixture.

[0015] In another embodiment, the absorbent bottom layer is made of fluffy nonwoven fabric, which is produced by mixing various chemical fibers and then using a hot air process.

[0016] According to one aspect of this application, one embodiment provides an absorbent article including a hydrophilic top layer and a waterproof bottom layer, and further including the aforementioned absorbent core, wherein the absorbent core is disposed between the hydrophilic top layer and the waterproof bottom layer.

[0017] In another embodiment, the waterproof substrate includes a PE film and a non-woven fabric substrate, and the hydrophilic surface layer has a three-dimensional protective barrier on each of its transverse sides to prevent side leakage.

[0018] According to the above embodiments, the absorbent core and absorbent product are integrated through an upper and lower double-layer composite structure combined with an outer covering layer. The upper second absorbent core layer, which is a mixture of wood pulp and polymer absorbent material, quickly captures and initially absorbs liquid. The liquid flows down through the multi-layer fiber layer and polymer absorbent layer of the first absorbent core layer, which quickly guides and deeply stabilizes the water, thereby achieving a comprehensive technical effect of rapid absorption, effective leakage prevention, prevention of core clumping and breakage, and improved wearing comfort. Attached Figure Description

[0019] Figure 1 This is a schematic cross-sectional view of the absorbent article in one embodiment;

[0020] Figure 2 This is a schematic diagram of the overall structure of the absorber core in Example 1;

[0021] Figure 3 This is a flowchart illustrating the manufacturing process of the absorber core in Example 1;

[0022] Figure 4 This is a schematic diagram of the structure of the first absorber core layer in Example 2;

[0023] Figure 5 This is a schematic diagram of the structure of the first absorber core layer in Example 2;

[0024] Figure 6 This is a schematic diagram of the overall structure of the absorber core in Example 3;

[0025] Figure 7 This is a schematic diagram of the overall structure of the absorbent product in Example 4.

[0026] Figure label:

[0027] 1. Hydrophilic top layer; 2. Waterproof bottom layer; 21. PE film; 22. Bottom non-woven fabric; 3. First absorbent core layer; 31. Absorbent top layer; 32. Polymer absorbent layer; 33. Absorbent bottom layer; 34. Front section; 35. Middle section; 36. Rear section; 4. Second absorbent core layer; 5. Covering layer; 6. 3D protective barrier; 7. Elastic band; 8. Left and right side patches; 9. Front waist patch. Detailed Implementation

[0028] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0029] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments, and the operational steps involved in each embodiment can also be rearranged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for clearly describing a particular embodiment and do not imply that they represent the necessary components and / or order.

[0030] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0031] With the aging population, the market demand for adult incontinence care products is growing. As the core component of diapers, the absorbent core's performance directly determines the product's absorption speed, leak-proof capability, comfort, and reliability.

[0032] Currently, the absorbent cores of mainstream adult diapers mainly adopt the following two structures: The first is a mixture of traditional fluff pulp and superabsorbent polymer (SAP). This structure is formed by mixing crushed wood pulp with SAP, then wrapping it with a covering paper and pressing it into shape. Its main disadvantages are: First, after absorbing liquid, the SAP expands, and the fluff pulp fiber network structure is damaged, which easily leads to "gel blockage," preventing the liquid from spreading effectively and causing leakage after local saturation; Second, the overall strength of this structure is low. When the user sits, lies down, or moves, the core is squeezed and twisted, which easily causes "clumping" or "fracture," interrupting the absorption channels. This not only seriously affects absorption efficiency but also leads to large-area leakage, causing great inconvenience and embarrassment to the user; Finally, to ensure a certain absorption capacity, this type of core often needs to be filled with a large amount of material, resulting in increased thickness, making it bulky, not close-fitting, and uncomfortable to wear.

[0033] The second type is the ultra-thin composite core, which typically uses materials such as dust-free paper and non-woven fabric to bond SAP layer by layer with hot melt adhesive to form a straight strip structure. This type of core is thinner, but its inherent disadvantages are equally obvious: First, SAP usually exists in a single, continuous layer, which is evenly distributed but lacks a flow gradient, resulting in a slow liquid infiltration rate and insufficient instantaneous absorption capacity, making it unable to cope with the sudden surge of large amounts of urine in adults; Second, because SAP is concentrated in a certain layer, after absorbing liquid, a large number of SAP particles expand and stick together, undergoing an "adhesive" reaction, which severely hinders the penetration and diffusion of subsequent liquids, causing a sharp decline in the second and third absorption capacity, and resulting in a very high risk of leakage in the later stages of use.

[0034] Therefore, this application provides an absorbent core and absorbent product that combines multiple advantages such as ultra-thin comfort, rapid absorption, strong water retention, compression resistance, anti-clumping and anti-fracture, and all-round leakage prevention to meet the high-standard care needs of adult users with moderate to severe incontinence.

[0035] Example 1:

[0036] Please refer to Figure 1 and Figure 2 This embodiment discloses an absorbent core, comprising: a first absorbent core layer 3, including at least two fiber layers and a polymer absorbent layer 32 disposed between the fiber layers; a second absorbent core layer 4, composited on the first absorbent core layer 3, and the second absorbent core layer 4 comprising a mixture absorbent layer of pulverized wood pulp and polymer absorbent material; and a covering layer 5, which covers the first absorbent core layer 3 and the second absorbent core layer 4 to form an integral structure.

[0037] In this embodiment, the absorbent core is integrated with an upper and lower double-layer composite structure and an outer covering layer 5. The upper second absorbent core layer 4, a mixture of wood pulp and polymer absorbent material, quickly captures and initially absorbs liquid. The liquid flows down through the multi-layer fiber layer and polymer absorbent layer 32 of the first absorbent core layer 3, which quickly guides and deeply stabilizes the water, thereby achieving a comprehensive technical effect of rapid absorption, effective leakage prevention, prevention of core clumping and breakage, and improved wearing comfort.

[0038] Please refer to Figure 2 The first absorbent core layer 3 is shaped like an irregular shape, and the second absorbent core layer 4 is shaped like a long rectangular strip. The second absorbent core layer 4 is located within the projection range of the second absorbent core layer 4 on the plane.

[0039] Please refer to Figure 1 and Figure 2 The multilayer fiber layer includes an absorbent surface layer 31 and an absorbent bottom layer 33 arranged from top to bottom, and the absorbent surface layer 31 is provided with at least one layer, and the polymer absorbent layer 32 is sandwiched between any two fiber layers.

[0040] This embodiment employs a unique double-layer composite structure characterized by "rapid top, stable bottom, and leak-proof irregular shape." The first absorbent core layer 3 constitutes the bottom basic structure of the core, which is composed of at least two fiber layers and a polymer absorbent layer 32 (SAP layer) disposed between them. This "fiber-SAP-fiber" sandwich structure is not a simple adhesive bonding process, but rather a specific process that firmly embeds the SAP within the fiber network.

[0041] Preferably, the first absorbent core layer 3 can be a three-layer structure, namely a sandwich structure of "fiber-SAP-fiber".

[0042] Furthermore, in this embodiment, the absorbent surface layer 31 is made of dust-free paper, which is produced by mixing wood pulp with chemical fibers and then reinforcing the mixture. The absorbent bottom layer 33 is made of fluffy non-woven fabric, which is produced by mixing various chemical fibers and then using a hot air process.

[0043] For details, please refer to Figure 1 and Figure 2The first absorbent core layer 3 has an absorbent surface layer 31 made of dust-free paper, which is made by mixing wood pulp with a small amount of chemical fiber and then using a hydroentangling process. It is tough and has excellent vertical flow properties, allowing for rapid downward transfer of upper liquid layers. The polymer absorbent layer 32 is a superabsorbent polymer (SAP) layer. This SAP layer is not uniformly distributed but is adsorbed and transferred through a customized irregularly shaped mold wheel, forming a specific discontinuous pattern distribution on the absorbent surface layer 31. This irregular distribution strategy allows the SAP to be concentrated in areas prone to leakage, achieving efficient material utilization. The absorbent bottom layer 33 is a fluffy non-woven fabric, made of polyester, polypropylene, and other chemical fibers using a hot-air process. It has numerous pores between the fibers, resulting in a fluffy and soft structure. Its main function is to provide temporary liquid storage space and a final water-locking layer, while also giving the core good flexibility.

[0044] For details, please refer to Figure 1 and Figure 2 The second absorbent core layer 4 directly covers the dust-free paper of the first absorbent core layer 3. The second absorbent core layer 4 is made of high-quality fluff pulp that has been pulverized and then uniformly mixed with granular SAP in a certain ratio (e.g., 3:1 or 5:1). The wood pulp fiber network of the mixture absorbent layer generates strong capillary force, which can instantly capture liquid and quickly guide it into the lower first absorbent core layer 3 for storage.

[0045] Specifically, in this embodiment, the entire core structure after the first absorbent core layer 3 and the second absorbent core layer 4 are combined is fully wrapped by a covering layer 5. The covering layer 5 can be made of spunbond or thermally rolled nonwoven fabric and is combined with the internal core by hot melt adhesive spot welding or ultrasonic welding to firmly integrate them into a one-piece structure, thereby ensuring that the core will not be scattered, deformed or broken during use.

[0046] During use, the liquid is rapidly guided by the second absorbent core layer 4 to the lower first absorbent core layer 3. The abundant SAP distributed within the first absorbent core layer expands fully under the support of the multi-layered fiber structure, locking in moisture. The fiber layers not only guide the flow but also separate the SAP, effectively preventing a "sticky" reaction after liquid absorption and ensuring stable performance across multiple absorption cycles. The lower, fluffy non-woven fabric structure provides ample space for liquid storage and diffusion.

[0047] For further details, please refer to... Figure 3 The manufacturing process of the absorber core in this embodiment includes the following steps:

[0048] S1: Wood pulp is crushed, mixed with chemical fibers, and reinforced to make dust-free paper, forming an absorbent surface layer 31;

[0049] S2: The polymer is adsorbed by a custom-shaped mold wheel and demolded onto the dust-free paper, forming a composite polymer absorption layer 32 and an absorption surface layer 31.

[0050] S3: A mixture of various chemical fibers is processed by hot air to form a fluffy non-woven fabric, which forms the absorbent bottom layer 33;

[0051] Among them, the semi-finished product after S1 and S2 are combined with the absorbent bottom layer 33 again to form the first absorbent core layer 3 of the three-layer absorber structure.

[0052] S4: Wood pulp is crushed and mixed with polymer to form a mixture absorption layer, and the mixture absorption layer is composited on top of the first absorption core layer 3 (i.e., absorption surface layer 31).

[0053] The mixture absorption layer can also be adsorbed and demolded using a long strip mold wheel to form a long rectangular second absorption core layer 4.

[0054] S5: The first absorbent core layer 3 and the second absorbent core layer 4 are wrapped with non-woven fabric to form an integrated structure.

[0055] S6: The absorption structure in S5 is shaped by irregular cutting to form the outer contour of the core, thereby forming the absorption core in this embodiment.

[0056] In this embodiment, the irregular outer contour is formed through final slitting. When a specially designed die cuts the multi-layer composite material (clean paper, SAP, non-woven fabric) at high speed, the blade applies tremendous pressure to the edge of the cut line at the instant of cutting. This pressure causes the multi-layer material at the cut edge to be instantly compacted and tightly fused together, forming a "locking edge" effect and creating a robust overall contour. Crucially, this effectively encloses the polymer SAP particles within the compacted edge, preventing them from detaching or leaking from the core side. Even under compression and twisting, the layers are less prone to misalignment, thus greatly reducing the risk of clumping and delamination.

[0057] In other embodiments, during the mixing process of wood pulp and SAP in the second absorbent core layer 4, appropriate amounts of antibacterial agents (such as silver ion antibacterial agents) and deodorizing molecules (such as activated charcoal powder or plant extracts) can be added. These additives can be evenly dispersed in the absorbent layer, acting continuously to inhibit bacterial growth and decompose odor molecules, thereby further improving the product's hygiene level and user experience.

[0058] Example 2:

[0059] Based on Embodiment 1, the difference in this embodiment lies in the irregular outer contour of the first absorbent core layer 3. See also... Figure 4 and Figure 5 By irregularly slicing the first absorbent core layer 3, it is given an outer contour with special effects.

[0060] For details, please refer to Figure 4Designed specifically for women, the first absorbent core layer 3 is a single-piece structure comprising a front section 34, a middle section 35, and a rear section 36 along its length. The front section 34 is narrower to accommodate the anterior physiological structure of women, while the rear section 36 is significantly wider, exhibiting a broad, curved profile. This design aims to provide maximum absorbent protection for the rear area of ​​the female user when she is in a supine position, greatly reducing the risk of posterior leakage.

[0061] For the rest, please refer to Figure 5 Designed specifically for men, the first absorbent core layer 3 is a single-piece structure comprising a front section 34, a middle section 35, and a rear section 36 along its length. Both the front section 34 and the rear section 36 are designed as wide and symmetrical arcs. Since male users' urine tends to flow forward, the wide front section 34 effectively intercepts and absorbs the forward-spreading urine; simultaneously, the widened rear section 36 provides additional protection against leakage.

[0062] It is important to emphasize that, in both of the aforementioned irregular designs, the second absorbent core layer 4 remains a long rectangular shape, but its length and width are smaller than those of the first absorbent core layer 3 below it, ensuring that its projection falls entirely within the planar projection range of the first absorbent core layer 3. This allows the rapidly absorbing second absorbent core layer 4 to focus on processing liquids in key areas, while the larger first absorbent core layer 3 can store liquids and handle any liquids that might spread to the edges.

[0063] This embodiment, by changing the shape of the irregularly shaped molded wheel in the first absorbent core layer 3, can easily generate optimized models for different genders or even other special needs. This makes the protection more targeted and more effective.

[0064] Example 3:

[0065] Based on Example 1, the focus of this example is the multilayer structure of the first absorbent core layer 3.

[0066] See Figure 6 The first absorbent core layer 3 can be a five-layer structure, namely a sandwich structure of "fiber-SAP-fiber-SAP-fiber". Specifically, from top to bottom, it consists of five alternating layers: absorbent surface layer 31 (dust-free paper), polymer absorbent layer 32, absorbent surface layer 31 (dust-free paper), polymer absorbent layer 32, and absorbent bottom layer 33 (fluffy non-woven fabric); or, it can be further layered according to requirements. By increasing the interlacing of fiber layers and SAP layers, the overall structural strength and integrity of the core are greatly enhanced, enabling it to withstand various stresses during use without dispersing or breaking.

[0067] In this embodiment, during the manufacturing of the absorbent core, after steps S1 and S2 are combined, the semi-finished product is combined with the absorbent bottom layer 33 again to form a three-layer absorbent structure. Then, based on the three-layer structure, steps S2 and S1 are performed again to form the first absorbent core layer 3 of a five-layer absorbent structure.

[0068] Example 4:

[0069] See Figure 2 and Figure 7 This embodiment provides an absorbent article using the absorbent core of any of the above embodiments. In this embodiment, the absorbent article is specifically an adult diaper, which includes a hydrophilic surface layer 1, a waterproof bottom layer 2, and an absorbent core, with the absorbent core disposed between the hydrophilic surface layer 1 and the waterproof bottom layer 2.

[0070] For details, please refer to Figure 2 and Figure 7 The hydrophilic outer layer 1 is typically made of hydrophilically treated non-woven fabric, which comes into direct contact with the skin, senses the liquid, and allows it to quickly seep in. The absorbent core is used to absorb, channel, and lock in the liquid. The waterproof bottom layer 2 includes a PE film 21 and a bottom non-woven fabric 22. The PE film 21 completely prevents liquid leakage, while the outer composite bottom non-woven fabric 22 provides a soft touch and an aesthetically pleasing fabric texture. On both sides of the hydrophilic outer layer 1, three-dimensional protective barriers 6 are welded or fixed in place. Elastic bands 7 can be provided on the inner side of the three-dimensional protective barriers 6 to allow them to stand upright and fit snugly against the user's groin, working in conjunction with the irregularly designed absorbent core to achieve comprehensive, three-dimensional leak-proof protection. One end of the waterproof bottom layer 2 has left and right tabs 8, and the other end has a front waist tab 9 to secure the left and right tabs 8 during use.

[0071] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. An absorbent core, characterized in that, include: The first absorbent core layer (3) includes at least two fiber layers and a polymer absorbent layer (32) disposed between the fiber layers; The second absorbent core layer (4) is composited on the first absorbent core layer (3), and the second absorbent core layer (4) includes a mixture absorbent layer of pulverized wood pulp and polymer absorbent material; And a covering layer (5) which covers the first absorbent core layer (3) and the second absorbent core layer (4) to form an integral structure.

2. The absorbent core as described in claim 1, characterized in that, The first absorbent core layer (3) is shaped like an irregular shape, the second absorbent core layer (4) is shaped like a long rectangular strip, and the second absorbent core layer (4) is located within the projection range of the second absorbent core layer (4) on the plane.

3. The absorbent core as described in claim 2, characterized in that, The first absorbent core layer (3) includes a front section (34), a middle section (35) and a rear section (36) in the length direction. The front section (34) and the rear section (36) are wider than the middle section (35), and the outer contours of the front section (34) and the rear section (36) are arc-shaped.

4. The absorbent core as described in claim 3, characterized in that, The width of the rear segment (36) is greater than the width of the front segment (34).

5. The absorbent core as described in claim 3, characterized in that, The front section (34) and the rear section (36) are symmetrically arranged about the middle section (35).

6. The absorbent core as described in claim 1, characterized in that, The multilayer fiber layer includes an absorbent surface layer (31) and an absorbent bottom layer (33) arranged from top to bottom, and the absorbent surface layer (31) is provided with at least one layer, and the polymer absorbent layer (32) is sandwiched between any two fiber layers.

7. The absorbent core as described in claim 6, characterized in that, The absorbent surface layer (31) is made of dust-free paper, which is made by mixing wood pulp with chemical fiber and then reinforcing it.

8. The absorbent core as described in claim 6, characterized in that, The absorbent bottom layer (33) is made of fluffy non-woven fabric, which is made by mixing various chemical fibers and then using a hot air process.

9. An absorbent article comprising a hydrophilic top layer (1) and a waterproof bottom layer (2), characterized in that, It also includes an absorbent core as described in any one of claims 1-8, wherein the absorbent core is disposed between the hydrophilic surface layer (1) and the waterproof bottom layer (2).

10. The absorbent article as claimed in claim 9, characterized in that, The waterproof bottom layer (2) includes a PE film (21) and a bottom non-woven fabric (22), and the hydrophilic surface layer (1) is provided with a three-dimensional protective enclosure (6) on each of its transverse sides to prevent side leakage.

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