A gourd-shaped double-layer structure absorbent core sanitary napkin

Abstract

This invention provides a gourd-shaped double-layer absorbent core sanitary napkin, belonging to the field of sanitary product technology. It includes an absorbent layer extending in the front-to-back direction, a surface layer disposed on the upper surface of the absorbent layer in contact with the skin, and a bottom layer disposed on the lower surface of the absorbent layer. Below the surface layer, a drainage layer for guiding liquid and a gourd-shaped core layer are sequentially arranged. The width of the middle of the gourd-shaped core layer is greater than the width of its front and back ends, allowing the gourd-shaped core layer to conform to the contours of the female genitalia. By setting the gourd-shaped core layer, the curve of its shape conforms to the female genitalia. When worn, the gourd-shaped core layer conforms to the female genitalia. Due to the support provided by the gourd-shaped core layer, a W-shaped structure is formed after the gourd-shaped core layer conforms to the genitalia. Liquid diffuses along the grooves formed by the W-shaped structure, reducing the possibility of side leakage caused by liquid flowing directly to the left and right sides.

Description

Technical Field

[0001] This invention relates to the field of hygiene products technology, specifically to a gourd-shaped double-layer absorbent core sanitary napkin. Background Technology

[0002] Sanitary napkins are essential hygiene products for women during menstruation. Their absorbent core, as the core functional structure, directly determines the product's fit, comfort, absorbent core utilization, leak-proof performance, and backflow prevention. Currently, most mainstream sanitary napkins on the market use rectangular or elongated symmetrical absorbent cores, employing fluff pulp combined with superabsorbent polymers as the core absorbent material. These cores are formed through homogeneous flattening and multi-layer stacking. While the structural design is simple and versatile, it suffers from structural defects such as easy deformation and displacement during actual use. This makes it difficult to adapt to the human body's physiological curves and the diverse usage scenarios during menstruation, resulting in a poor user experience.

[0003] The female genitalia are not a regular shape, and daily movements such as walking, sitting, and turning over cause dynamic deformation. A standard rectangular core with a uniform width at both ends cannot match the natural curves of the human body. When worn, gaps easily form between the front and back areas of the core and the skin, while the middle area tends to be overly tight and compress the skin. During physical activity, the core is prone to wrinkling, and menstrual blood can easily seep through the gaps at the front and back and side seams, significantly reducing the product's reliability.

[0004] Secondly, traditional absorbent cores have slow liquid absorption rates and are prone to localized saturation. Current cores use a homogeneous planar structure with no differentiated areas, causing menstrual blood to concentrate in the central core area. This easily leads to rapid saturation of the central absorbent resin, resulting in liquid accumulation, localized water-locking saturation, and clogging. Meanwhile, the absorbent materials at the front and back ends of the core remain largely unused, resulting in extremely low overall core utilization. Furthermore, traditional static homogeneous cores are prone to pore collapse and stress buildup after absorbing liquid and expanding. Repeated absorption can lead to backflow, resulting in a damp and sticky surface that not only affects dryness but also promotes bacterial growth, which is detrimental to menstrual hygiene.

[0005] Finally, traditional core designs struggle to balance comfort and practicality. To address leakage, most existing products increase the absorbent area by widening and thickening the core. While this improves retention capacity to some extent, it results in a bulky and stiff sanitary napkin, causing noticeable friction against the skin, and making it stuffy and unbreathable, severely impacting comfort during daily activities. Ultra-thin, standardized core designs, lacking structural optimization, suffer from insufficient absorbency and a tendency to leak, failing to achieve a balance between lightweight comfort, efficient absorption, and precise leak prevention. Summary of the Invention

[0006] This invention provides a gourd-shaped double-layer absorbent core sanitary napkin to solve the technical problems in the prior art.

[0007] To solve the above problems, the gourd-shaped double-layer absorbent core sanitary napkin provided by the present invention adopts the following technical solution: it includes an absorbent layer extending in the front-back direction, a surface layer disposed on the upper surface of the absorbent layer that contacts the skin, and a bottom layer disposed on the lower surface of the absorbent layer. Below the surface layer, there is a guide layer for guiding liquid and a gourd-shaped core layer in sequence. The width of the middle of the gourd-shaped core layer is greater than the width of the front and rear ends, so that the gourd-shaped core layer fits the contour of the female private parts. The width of the gourd-shaped core layer is smaller than that of the absorption layer. The gourd-shaped core layer and the absorption layer form an upper and lower gradient difference, which makes a V-shaped absorption groove for temporary liquid storage formed between the side of the gourd-shaped core layer, the lower surface of the guide layer, and the upper surface of the absorption layer.

[0008] As a further improvement, the width of the front or rear end of the gourd-shaped core layer is 10-20mm, and the width of the middle section of the gourd-shaped core layer is 25-40mm.

[0009] As a further improvement, the gourd-shaped core layer includes an absorbent core and a piece of toilet paper disposed on the outer surface of the absorbent core for wrapping the absorbent core. The absorbent core includes wood pulp and superabsorbent polymer evenly distributed in the pores of the wood pulp. The mass of the wood pulp is 0.8-1g and the mass of the superabsorbent polymer is 0.2-0.5g.

[0010] As a further improvement, the portion of the gourd-shaped core layer that protrudes to the left and right sides in the middle section is semi-circular or semi-elliptical.

[0011] As a further improvement, the surface layer is a hot-air nonwoven fabric made of a mixture of coarse and fine denier fibers, with the fine denier fibers being 1.2-2D and the coarse denier fibers being 1.5-6D, and the density of the hot-air nonwoven fabric being 0.093-0.105 g / cm³.

[0012] As a further improvement, the pore size of the surface layer is 9-12 μm.

[0013] As a further improvement, the flow guiding layer is a 4-6D nonwoven fabric with a pore size of 25-40μm.

[0014] As a further improvement, the bottom layer is uniformly distributed with breathable micropores of 0.1-0.3μm.

[0015] The beneficial effects of the above-described technical solution of the present invention are as follows: 1. This invention features a gourd-shaped core layer whose shape and curve conform to the female private parts. When worn, the gourd-shaped core layer conforms to the female private parts, and because it provides some support, it forms a W-shaped structure after fitting with the private parts. Liquid diffuses along the groove formed by the W-shaped structure, reducing the risk of leakage caused by liquid flowing directly to the left and right sides.

[0016] The gourd-shaped core layer has an absorption layer underneath. Due to the inconsistent width between the gourd-shaped core layer and the absorption layer, a gradient difference is formed. A V-shaped absorption groove is formed between the side of the gourd-shaped core layer, the lower surface of the guide layer, and the upper surface of the absorption layer to temporarily store liquid. After wearing, the V-shaped absorption groove will become more obvious. Menstrual blood seeps into this area and diffuses and is absorbed. If a large amount of liquid seeps into the area, it will also be temporarily stored in the V-shaped absorption groove area and guided and absorbed along the edge of the gourd-shaped core layer to avoid local core absorption becoming too saturated.

[0017] 2. The surface layer of this invention uses a combination of coarse and fine denier fabrics. The 1.2-2D fine denier hot-air nonwoven fabric has the advantages of fine and soft fibers, fluffy and lightweight, and good curvature conformability. Compared with the existing surface layer of coarse and ultra-fine denier fabrics, the liquid penetration time of the surface layer of this invention is increased by about 50%, realizing rapid vertical liquid penetration and greatly reducing the problems of lateral liquid flow and surface liquid retention. At the same time, it also has excellent breathability and skin-friendliness.

[0018] The flow-guiding layer uses 4-6D loose non-woven fabric. The pore size of the 4-6D loose non-woven fabric is between 25-40μm, which is 2-3.5 times larger than that of the surface layer. This allows the liquid to seep down quickly, resulting in stronger pore penetration and better structural support. The pores, which are smaller at the top and larger at the bottom, effectively form a three-dimensional flow-guiding cavity: the small pores of the surface layer are responsible for "rapid vertical seepage, locking in residual liquid on the surface, and reducing liquid backflow," while the large pores of the flow-guiding layer are responsible for "rapid diversion, uniform lateral diffusion, and slow release and convergence." This allows the concentrated dripping menstrual blood to be quickly and evenly spread to the width-fitting area of ​​the gourd-shaped core layer, preventing the liquid from accumulating in the middle of the core and causing local saturation and blockage. Attached Figure Description

[0019] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein: Figure 1 This is a schematic diagram of the structure of the gourd-shaped double-layer absorbent core sanitary napkin of the present invention; Figure 2 This is a schematic diagram of the surface layer of the gourd-shaped double-layer absorbent core sanitary napkin of the present invention; Figure 3 This is a schematic diagram comparing the surface layer pore size and the flow-guiding layer pore size of the gourd-shaped double-layer absorbent core sanitary napkin of the present invention. Figure 4 This is a schematic diagram of the gourd-shaped core layer of the gourd-shaped double-layer absorbent core sanitary napkin of the present invention; Figure 5 This is a reference diagram showing the usage state of the gourd-shaped double-layer absorbent core sanitary napkin of the present invention; Figure 6 This is a liquid diffusion diagram of the sanitary napkin with a gourd-shaped double-layer absorbent core structure of the present invention in the wearing state; Figure 7 This is a schematic diagram of the V-shaped absorbent groove in the gourd-shaped double-layer absorbent core sanitary napkin of the present invention; Figure 8 This is a schematic diagram of the V-shaped absorbent groove in the wearing state of the gourd-shaped double-layer absorbent core sanitary napkin of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Surface layer; 2. Flow guiding layer; 3. Gourd-shaped small core layer; 4. Absorption layer; 5. Bottom layer. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art should understand that the embodiments described below are only some, not all, of the embodiments disclosed. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] In existing technologies, conventional rectangular cores have a uniform width at both ends, which cannot match the natural curves of the human body. When worn, gaps easily form between the front and back areas of the core and the skin, while the middle area tends to be overly tight and compress the skin. During physical activity, the core is prone to wrinkling, and menstrual blood can easily seep through the gaps at the front and back and side seams, significantly reducing the product's reliability. Currently, there are some improvements designed to address the contours of the female genitalia, such as using grooves to align the genitalia with the grooves, thereby reducing the risk of side leakage. However, the problem with this type of structure is that its breathability is relatively poor, easily leading to a stuffy and damp feeling.

[0023] Secondly, traditional cores have slow liquid absorption rates and are prone to localized saturation. Furthermore, traditional cores often struggle to balance comfort and practicality.

[0024] Regarding the above-mentioned problems, the inventive concept of this invention is as follows: First, the surface layer 1 and the flow guiding layer 2 are optimized. The surface layer 1 of this invention uses a combination of 1.5~6D coarse denier and 1.2-2D fine denier. The 1.2-2D fine denier hot-air nonwoven fabric has the advantages of fine and soft fibers, fluffy and thin texture, and good curvature conformability. Compared with the existing surface layer 1 with coarse denier and ultra-fine denier, the liquid penetration time of the surface layer 1 of this invention is increased by about 50%. The surface layer 1 of this invention has a uniform and dense three-dimensional microporous structure with a pore size concentrated in 9-12μm and a porosity of 75%-85%. Compared with conventional coarse denier nonwoven fabric, the pore size is more uniform and the connectivity is better. Compared with ultra-fine denier, the pore size is larger, which realizes rapid vertical liquid penetration, greatly reduces the problem of lateral liquid flow and surface liquid retention, and at the same time has excellent air permeability and skin-friendliness.

[0025] The flow-guiding layer 2 is made of 4-6D loose non-woven fabric. The pore size of the 4-6D loose non-woven fabric is between 25-40μm, and the porosity is as high as 88%-92%, which is 2-3.5 times different from that of the surface layer 1. This allows the liquid to seep down quickly, and the pores have stronger permeability and better structural support. The pores, which are smaller at the top and larger at the bottom, effectively form a three-dimensional flow-guiding cavity: the small pores of the surface layer 1 are responsible for "rapid vertical seepage, locking the surface residual liquid, and reducing liquid backflow", while the large pores of the flow-guiding layer 2 are responsible for "rapid diversion, uniform lateral diffusion, and slow release and convergence". This allows the concentrated dripping menstrual blood to be quickly and evenly spread to the wide and narrow matching area of ​​the gourd-shaped small core layer 3, avoiding the accumulation of liquid in the middle of the core and causing local saturation and blockage.

[0026] Meanwhile, 4-6D fluffy fibers exhibit excellent compression resistance and resilience, maintaining a stable pore structure even under pressure. The superior elastic recovery of 4-6D fluffy fibers means that when the fiber stack is subjected to external pressure, the fibers only undergo reversible bending deformation and do not stick together. After the pressure is released, the fibers quickly spring back to their original shape, preserving the complete three-dimensional porous skeleton. The interconnected pore structure does not permanently collapse, maintaining a uniform and stable hollow air-permeable gap. Even after prolonged wear, the pores do not collapse or harden, continuously ensuring unobstructed fluid conduction.

[0027] Secondly, the absorption structure adopts a design of gourd-shaped core layer 3 plus conventional absorption layer 4. The shape and curve of the gourd-shaped core layer 3 fits the female private parts. When worn, the gourd-shaped core layer 3 fits the female private parts. Since the gourd-shaped core layer 3 has a certain support function, it forms a W-shaped structure after fitting with the private parts. The liquid diffuses back and forth along the groove formed by the W-shaped structure, reducing the possibility of liquid flowing directly to the left and right sides and causing side leakage.

[0028] The gourd-shaped core layer 3 has an absorption layer 4 underneath. Due to the inconsistent widths of the gourd-shaped core layer 3 and the absorption layer 4, a gradient difference is formed. A V-shaped absorption groove for temporarily storing liquid is formed between the side of the gourd-shaped core layer 3, the lower surface of the guide layer 2, and the upper surface of the absorption layer 4. After wearing, the V-shaped absorption groove will be more obvious. Menstrual blood seeps into this area and diffuses and is absorbed. If a large amount of liquid seeps into the area, it will also be temporarily stored in the V-shaped absorption groove area and guided and absorbed along the edge of the gourd-shaped core layer 3 to avoid local core absorption being too saturated.

[0029] After introducing the basic principles of the present invention, various non-limiting embodiments of the present invention are described in detail below. Any number of elements in the accompanying drawings is for illustrative purposes only and not for limitation, and any naming is for distinction only and has no limiting meaning.

[0030] The principles and spirit of the present invention will be explained in detail below with reference to several representative embodiments.

[0031] Example 1 of the gourd-shaped double-layer absorbent core sanitary napkin provided by the present invention: like Figures 1-8 As shown, the gourd-shaped double-layer absorbent core sanitary napkin includes an absorbent layer 4 extending in the front-to-back direction, a surface layer 1 disposed on the upper surface of the absorbent layer 4 and in contact with the skin, and a bottom layer 5 disposed on the lower surface of the absorbent layer 4. like Figure 2 As shown, surface layer 1 is a hot-air nonwoven fabric made of a mixture of coarse and fine denier fibers. The fine denier fibers are 1.2-2D, and the coarse denier fibers are 1.5-6D. The 1.5-6D coarse denier fibers act as a framework, providing rigid support, while the 1.2-2D fine denier fibers are added to the framework established by the coarse denier fibers for cross-linking (as shown in the figure, black represents coarse denier fibers, and red represents fine denier fibers). The density of the hot-air nonwoven fabric is 0.093-0.105 g / cm³, and the pore size of surface layer 1 is 9-12 μm. When the product is not under pressure (sitting, resting), the addition of fine denier fibers to surface layer 1 can appropriately improve the softness of the product, while the coarse denier fibers increase the porosity between the fibers, allowing the body to absorb and absorb blood / liquid. The combination of coarse and fine fibers makes the product soft and skin-friendly while accelerating absorption. When the body is in motion (walking, running, squatting), the product is subjected to pressure, and the density of the material increases by 20%-40%, thereby reducing the gaps between the materials. At this time, the fine denier surface layer 1 acts as a barrier, effectively preventing the product from seeping back.

[0032] like Figure 3As shown, a flow guiding layer 2 for guiding liquid is sequentially provided below the surface layer 1. The flow guiding layer 2 is a 4-6D nonwoven fabric with a pore size of 25-40μm. The porosity of the flow guiding layer 2 is as high as 88%-92%, which is 2-3.5 times different from the pore size of the surface layer 1, allowing the liquid to seep down quickly, with stronger pore penetration and better structural support.

[0033] The gourd-shaped core layer 3 is located between the flow guiding layer 2 and the absorption layer 4. The width in the middle of the gourd-shaped core layer 3 is greater than the width at both ends, so that the gourd-shaped core layer 3 fits the contour of the female private parts. The width of the front or rear end of the gourd-shaped small core layer 3 is 10-20mm, the width of the middle section of the gourd-shaped small core layer 3 is 25-40mm, and the part of the middle section of the gourd-shaped small core layer 3 that protrudes to the left and right is semi-circular or semi-elliptical, and a transition curve is set to ensure a smooth transition and ensure wearing comfort.

[0034] The gourd-shaped core layer 3 includes an absorbent core and a piece of toilet paper disposed on the outer surface of the absorbent core for wrapping the absorbent core. The absorbent core includes wood pulp and superabsorbent polymer evenly distributed in the pores of the wood pulp. The mass of the wood pulp is 0.8-1g and the mass of the superabsorbent polymer is 0.2-0.5g.

[0035] The gourd-shaped core layer 3 is integrally molded using a demolding wheel to achieve its gourd shape. The overall outline is demolded and shaped precisely, resulting in a human-fitting curve with a narrow front (10-20mm), a wide middle (25-40mm), and a narrow back (10-20mm) profile that conforms to the female intimate area. After shaping, the gourd-shaped core layer 3 is completely wrapped with toilet paper, providing comprehensive coverage of the internal wood pulp and superabsorbent polymer particles (using ribbon-type superabsorbent polymer for faster absorption). This effectively prevents the wood pulp from clumping, delaminating, and the polymer particles from shifting and falling off during use, significantly improving the overall structural stability of the core. After wrapping, excess toilet paper is precisely trimmed using a curved core cutter, resulting in a more stable core structure during use and preventing delamination of the gourd-shaped core layer 3.

[0036] The width of the gourd-shaped core layer 3 is smaller than that of the absorption layer 4. The gourd-shaped core layer 3 and the absorption layer 4 form an upper and lower gradient difference, which makes a V-shaped absorption groove for temporary liquid storage formed between the side of the gourd-shaped core layer 3 and the lower surface of the flow guiding layer 2 and the upper surface of the absorption layer 4.

[0037] When worn, the gourd-shaped core layer 3 conforms to the female intimate area. Because the gourd-shaped core layer 3 provides some support, it forms a W-shaped structure after fitting against the intimate area. The liquid diffuses back and forth along the grooves formed by the W-shaped structure. When the body walks, the liquid flows out instantly and is stored in the W-shaped structure, diffusing back and forth with the frequency of walking, thus increasing the product's absorption speed. Simultaneously, the liquid can also be guided along the sides of the gourd at a 20°-45° gradient (e.g., ...). Figure 6 As shown in the diagram, points A and B curve upwards to fit the private area, serving both an absorption and diversion function. First, diversion occurs along points A and B, followed by diagonal diversion at a 45° angle. Absorption occurs during the liquid flow. After the liquid flows to the composite core on both sides, it combines with the V-shaped absorption groove formed below to draw the liquid to the bottom of the gourd-shaped core for absorption, greatly improving the utilization rate of the product's absorption core layer. This V-shaped absorption groove has a diversion function.

[0038] After wearing, the V-shaped absorption groove will become more prominent. Menstrual blood will diffuse and be absorbed in this area. If a large amount of fluid seeps in, it will also be temporarily stored in the V-shaped absorption groove area and guided and absorbed along the edge of the gourd-shaped core layer 3 to avoid local core absorption becoming too saturated.

[0039] In this embodiment, the bottom layer 5 is evenly distributed with breathable micropores of 0.1-0.3μm. The pore size is smaller than the aggregate size of water molecules and larger than the aggregate size of air molecules, which can achieve the core performance of "breathable but not water-permeable". The measured air permeability is ≥300mm / s, which is more than 40% more breathable than ordinary dense non-porous bottom membrane. It can quickly expel the hot and humid gas inside the core, eliminate the problems of stuffiness, sweating and dampness during menstruation, and greatly improve the comfort of long-term wear.

[0040] While various embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. The appended claims are intended to define the scope of the invention and therefore cover any modular compositions, equivalents, or alternatives within the scope of these claims.

Claims

1. A gourd-shaped double-layer absorbent core sanitary napkin, comprising an absorbent layer (4) extending in the front-back direction, a surface layer (1) disposed on the upper surface of the absorbent layer (4) in contact with the skin, and a bottom layer (5) disposed on the lower surface of the absorbent layer (4). Its features are, Below the surface layer (1), there is a guide layer (2) for guiding liquid and a gourd-shaped core layer (3) in sequence. The width of the middle of the gourd-shaped core layer (3) is greater than the width of the front and rear ends, so that the gourd-shaped core layer (3) fits the contour of the female private parts. The width of the gourd-shaped core layer (3) is smaller than that of the absorption layer (4). The gourd-shaped core layer (3) and the absorption layer (4) form an upper and lower gradient difference, so that a V-shaped absorption groove for temporarily storing liquid is formed between the side of the gourd-shaped core layer (3), the lower surface of the guide layer (2), and the upper surface of the absorption layer (4).

2. The gourd-shaped double-layer absorbent core sanitary napkin according to claim 1, characterized in that: The width of the front or rear end of the gourd-shaped core layer (3) is 10-20mm, and the width of the middle section of the gourd-shaped core layer (3) is 25-40mm.

3. The gourd-shaped double-layer absorbent core sanitary napkin according to claim 2, characterized in that: The gourd-shaped core layer (3) includes an absorbent core and a tissue paper disposed on the outer surface of the absorbent core for wrapping the absorbent core. The absorbent core includes wood pulp and superabsorbent polymer evenly distributed in the wood pulp pores. The mass of the wood pulp is 0.8-1g and the mass of the superabsorbent polymer is 0.2-0.5g.

4. The gourd-shaped double-layer absorbent core sanitary napkin according to claim 3, characterized in that: The middle section of the gourd-shaped core layer (3) protrudes to the left and right sides in a semi-circular or semi-elliptical shape.

5. The gourd-shaped double-layer absorbent core sanitary napkin according to claim 1, characterized in that: The surface layer (1) is a hot-air nonwoven fabric made of a mixture of coarse denier fibers and fine denier fibers. The fine denier fibers are 1.2-2D, the coarse denier fibers are 1.5-6D, and the density of the hot-air nonwoven fabric is 0.093-0.105g / cm³.

6. The gourd-shaped double-layer absorbent core sanitary napkin according to claim 5, characterized in that: The surface layer (1) has a pore size of 9-12 μm.

7. The gourd-shaped double-layer absorbent core sanitary napkin according to claim 1, characterized in that: The flow guiding layer (2) is a 4-6D nonwoven fabric with a pore size of 25-40μm.

8. The gourd-shaped double-layer absorbent core sanitary napkin according to claim 1, characterized in that: The bottom layer (5) is evenly distributed with breathable micropores of 0.1-0.3μm.

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