A multi-layer composite medical water-absorbing spacer and a preparation method thereof

Abstract

The application discloses a multilayer composite medical water-absorbing spacer and a preparation method thereof, and relates to the technical field of medical consumables. The application comprises a layered structure which is sequentially arranged from top to bottom: a liquid-permeable contact layer, a primary absorption layer, a liquid flow guide layer, an integrated flow guide net, a suction catheter layer, a liquid retention layer and a liquid-impermeable backing layer. The core innovation is that the suction catheter layer is provided with active suction. Through integration of the active liquid suction and the negative pressure system, continuous and efficient liquid flow guide and discharge of the water-absorbing spacer are realized, so that the long-term effective water absorption capacity of the water-absorbing spacer is maintained, and the patient care quality and the medical operation efficiency are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of medical consumables technology, specifically to a multi-layer composite absorbent pad for medical use and its preparation method. Background Technology

[0002] In modern medical practice, absorbent pads have become indispensable consumables, with a wide range of applications, covering scenarios from routine wound care and fluid management during surgery to fluid absorption in incontinent patients. These products play a crucial role in maintaining patient skin dryness and cleanliness, preventing infection, improving comfort, and optimizing medical procedures. With the continuous advancement of medical technology and increasingly stringent requirements for patient care standards, the market's performance demands for absorbent pads are becoming more stringent, especially in terms of high-efficiency absorbency, long-term functionality, and structural integration. Traditional absorbent pad solutions are facing unprecedented challenges.

[0003] Traditional absorbent pads, regardless of their sophisticated material composition or structural design, operate on a finite, static, passive absorption and storage mechanism. The absorbent material absorbs and temporarily traps liquid through capillary action or the expansion of superabsorbent polymers (SAPs). Once the internal pores are filled, or the absorbent polymer reaches its saturation limit, its absorbency drops sharply or is completely lost. This "first absorb, then fill, then fail" characteristic inevitably exposes performance bottlenecks when facing high-throughput, long-term, or sudden large-volume liquid management needs. Specifically, even if the total capacity of the absorbent pad still has room to spare, rapid saturation in localized areas can significantly reduce its overall absorption efficiency, preventing liquid from being effectively guided to unsaturated areas and resulting in resource waste. More importantly, this passive absorption mode lacks a continuous and dynamic liquid management mechanism, failing to actively drain absorbed liquid from the pad's interior to regenerate or maintain its "activity." This inherent limitation not only leads to frequent replacement needs and increases medical waste, but more importantly, in medical settings where a dry environment needs to be maintained for a long time (such as major surgery, intensive care, and long-term bed rest), it cannot provide continuous and reliable water absorption, which can easily lead to problems such as backflow and side leakage, thereby affecting the patient's skin health and even increasing the risk of infection. This has a negative impact on the work efficiency of medical staff and the quality of life of patients.

[0004] For example, the butterfly-shaped molded nipple pad disclosed in patent application CN101926518A has a core design based on the use of vertically distributed absorbent layers. This design attempts to alleviate the problem of rapid saturation of a single absorbent layer by activating uncontaminated or unsaturated absorbent layer areas at different times, thereby providing users with a longer effective usage period. However, although the butterfly-shaped molded nipple pad has shown certain advantages in specific application scenarios, it is still a traditional absorbent pad based on a limited, static, passive absorption and storage mechanism. It still has the inherent limitations of traditional absorbent pads. First, the absorbency of its absorbent layer is essentially limited by the static absorption capacity of the material itself, and its structure lacks an active and effective liquid diversion and distribution mechanism. This means that when faced with continuous or localized high-flow-rate bodily fluid exudation, the absorbent area may quickly reach local saturation, leading to uneven absorption or localized liquid accumulation. Secondly, this structure relies on manual adjustment of the upper and lower absorbent layers to achieve functional conversion. If this invention is applied to a medical environment that highly values ​​efficiency and hygiene, it will undoubtedly increase the operational burden on medical staff. It may not only waste valuable time, but also increase the risk of infection due to contamination of the unsaturated absorbent layer's absorbent area.

[0005] Another patent application, CN114652537A, discloses a nursing device for urology. This device, by incorporating an absorbent pad within a groove in the bed frame and innovatively combining it with a heating mechanism, aims to keep the patient's buttocks dry and warm, thereby significantly improving patient comfort. This approach focuses on deeply integrating absorbency with the patient experience, attempting to assist in fluid management through external environmental control to achieve better nursing outcomes. However, a closer examination of this urology nursing device reveals that its absorbent pad design still primarily relies on traditional passive absorption principles, lacking a multi-layered composite structure to achieve efficient fluid absorption, rapid conduction, and reliable fluid locking. The heating mechanism only ensures the patient doesn't get cold, not damp. This means that after absorbing a large amount of fluid, the absorbent pad still carries a high risk of backflow or seepage. Under pressure, absorbed fluid may seep back onto the patient's skin surface or directly permeate the bed sheet, thus deviating from the initial goal of keeping the skin dry and potentially causing secondary problems such as maceration.

[0006] Therefore, how to overcome the limitations of the static absorption capacity of traditional absorbent pads and design a multi-layer composite structure that can achieve continuous and efficient liquid diversion and drainage while maintaining its effective water absorption capacity to meet the needs of the medical field for long-term, high-fluidity body fluid management has become a key challenge and an urgent technical problem for those skilled in the art. Summary of the Invention

[0007] This invention provides a multi-layer composite absorbent medical pad and its preparation method, aiming to fundamentally solve the technical defects of existing absorbent pads, such as insufficient absorbency, easy saturation, lack of continuous dynamic liquid management mechanism, and the risk of liquid backflow and side leakage. This invention integrates an active liquid extraction and negative pressure system to achieve continuous and efficient liquid diversion and drainage of the absorbent pad, thereby maintaining its long-term effective absorbency and significantly improving patient care quality and medical operation efficiency.

[0008] The technical solution adopted in this invention is as follows:

[0009] One of the objectives of this invention is to provide a multi-layer composite medical absorbent pad, characterized in that it comprises a layered structure stacked from top to bottom: a liquid-permeable contact layer, a primary absorbent layer, a liquid guiding layer, an integrated guiding mesh, an extraction catheter layer, a liquid retention layer, and a liquid-impermeable backing layer.

[0010] The liquid-permeable contact layer is composed of a hydrophilic, highly breathable, and non-irritating composite nonwoven fabric that is unidirectionally moisture-wicking.

[0011] The primary absorbent layer is a three-dimensional wood pulp cellulose web prepared by an airflow web-forming process. Superabsorbent polymer (SAP) particles are distributed in the wood pulp cellulose three-dimensional web, and the superabsorbent polymer particles are distributed in a multi-layer gradient distribution with a sparse upper layer and a dense lower layer in the wood pulp cellulose three-dimensional web.

[0012] The liquid guiding layer is made of a material with a three-dimensional structure, high porosity and high compressibility resilience.

[0013] The integrated flow guiding net is disposed between the liquid flow guiding layer and the extraction conduit layer to achieve bridging of the liquid between the liquid flow guiding layer and the extraction conduit layer;

[0014] The extraction conduit layer includes at least one extraction conduit, which is provided with multiple liquid suction holes. One or both ends of the extraction conduit extend to the edge of the absorbent pad and are connected to a negative pressure connection port that is connected to an external negative pressure generation and control system.

[0015] The liquid retention layer is composed of a cellulose fiber-reinforced absorbent resin composite material, serving as a buffer layer to provide additional water absorption protection. The absorbent resin content in the liquid retention layer is preferably 60-70% by mass, and the cellulose fiber content is preferably 30-40% by mass. The absorbent resin is preferably a sodium polyacrylate crosslinked polymer with high absorbency and high water retention capacity, providing reliable liquid locking capability to prevent liquid penetration into the impermeable backing layer when the negative pressure system is temporarily shut down or when the instantaneous liquid volume is excessive.

[0016] The impermeable backing layer is made of a thin film material that is impermeable to liquids and has good flexibility, preferably a medical-grade polyethylene (PE) film, polypropylene (PP) film, or polyurethane (PU) film, with a thickness of 20~50μm. It has good puncture resistance and moisture permeability but impermeability to liquids, that is, it allows water vapor to pass through to improve air permeability, but liquids cannot pass through, thereby maintaining the breathability of the patient's skin and preventing liquid leakage.

[0017] The multi-layer composite medical absorbent septum provided by this invention achieves dynamic and proactive management of medical bodily fluids through the aforementioned structural design. Its working principle is as follows: When bodily fluids seep into the absorbent septum, they first rapidly penetrate through the liquid-permeable contact layer to the primary absorbent layer for initial absorption. Subsequently, the liquid stored in the primary absorbent layer is uniformly guided to the liquid guiding layer under capillary action and negative pressure. Within the liquid guiding layer, the liquid is further evenly distributed and guided to the tiny suction holes of the extraction catheter in the extraction catheter layer. At this point, the negative pressure maintained by the external negative pressure generation and control system draws the liquid through the suction holes into the extraction catheter, and finally collects it in the liquid collection container through connecting pipes. This continuous negative pressure extraction process continuously removes the liquid inside the absorbent septum, thereby "regenerating" the absorbency and guiding capacity of the primary absorbent layer and the liquid guiding layer, maintaining a highly efficient absorbent state over a long period. If the instantaneous liquid volume is too large or the negative pressure system is temporarily shut down, the liquid retention layer will act as a buffer layer to provide additional absorbent protection.

[0018] As a preferred embodiment, the composite nonwoven fabric used to prepare the liquid-permeable contact layer includes an upper hydrophobic layer and a lower hydrophilic layer. The hydrophobic layer achieves a contact angle greater than 90° through plasma fluorocarbon finishing, and the pore diameter of the hydrophobic layer is 20-30 μm. The hydrophilic layer achieves a contact angle less than 60° through nonionic surfactant finishing or plasma hydrophilic treatment, and the pore diameter of the hydrophilic layer is 40-60 μm. In this invention, the liquid-permeable contact layer is disposed on the top layer of the absorbent pad, directly contacting the patient's skin. Therefore, the liquid-permeable contact layer is composed of a hydrophilic, non-irritating, highly breathable material with excellent fluid conductivity. This invention uses a bilayer composite structure with a transition from micro-hydrophobic to hydrophilic properties, combined with a gradient pore size design (20-30 μm for the upper layer and 40-60 μm for the lower layer), forming a capillary pressure difference from the upper surface to the lower surface, achieving directional liquid transport, thereby effectively preventing liquid backflow.

[0019] As a preferred embodiment, the primary absorbent layer is configured with a gradient density structure comprising an upper layer, a middle layer, and a lower layer. The upper layer has a water-absorbing resin particle content of 20-30% by mass and a wood pulp fiber length of 0.5-1.0 mm; the middle layer has a water-absorbing resin particle content of 30-40% by mass and a wood pulp fiber length of 1.5-2.0 mm; the lower layer has a water-absorbing resin particle content of 40-50% by mass and a wood pulp fiber length of 2.5-3.0 mm; and the total thickness of the primary absorbent layer is 5-10 mm. In this invention, the SAP is preferably a sodium polyacrylate crosslinked polymer. In the gradient density structure, the upper layer is used for rapid liquid absorption, avoiding liquid retention between the liquid-permeable contact layer and achieving a smooth transition; the main function of the middle layer is to efficiently conduct liquid to the lower layer, and the lower layer serves as a liquid-locking buffer. This gradient structure achieves a smooth transition from "rapid guidance" to "absorption and locking," effectively improving water absorption efficiency. Furthermore, the gradient absorption results in a smaller water storage capacity in the upper layer, which experiences greater stress, effectively reducing the probability of upward backflow under pressure. The primary absorbent layer's main function is to initially and rapidly absorb and store permeated bodily fluids, and to effectively guide the liquid to the underlying fluid-conducting layer using capillary forces between fibers. The primary absorbent layer possesses sufficient structural integrity and compressive elasticity to withstand the pressure from the patient's body without significantly affecting its absorbency or fluid transport path.

[0020] As a preferred embodiment, the liquid guiding layer is made of PET three-dimensional mesh spacer fabric with a thickness of 6-8 mm and a porosity of not less than 85%. The upper and lower surfaces of the liquid guiding layer are uniformly molded with an array of micro-protrusions with a height of 0.5-0.8 mm, and the distribution density of the micro-protrusions is 20-30 per cm. 2 The micro-protrusions are conical or pyramidal in shape; the primary absorbent layer has a micro-groove array that matches the micro-protrusion array. The liquid guiding layer is located below the primary absorbent layer, and its core function is to uniformly guide the liquid to the extraction catheter layer. The PET three-dimensional mesh spacer fabric used in this invention has interconnected pores that form a highly efficient capillary network, enabling the liquid absorbed from the primary absorbent layer to be quickly and uniformly conducted to the extraction catheter layer under gravity and negative pressure. PET has excellent compression resilience and sufficient mechanical strength and pressure resistance, effectively preventing the upper structure from collapsing and blocking the liquid inlet of the extraction catheter layer under negative pressure or when the patient's body is under pressure. The liquid guiding layer also serves as a preliminary filter for the liquid from the primary absorbent layer, preventing larger particles from entering the extraction catheter layer and causing blockage.

[0021] More preferably, the integrated flow guiding net is a PET / Co-PET bicomponent warp-knitted mesh fabric with a mesh aperture ratio of 0.9 to 1:1 to ensure that the micro-protrusions on the liquid flow guiding layer can effectively insert into or fit the mesh of the integrated flow guiding net, forming a stable mechanical interlocking structure. The PET / Co-PET bicomponent warp-knitted mesh fabric also has surface capillary grooves and a three-dimensional structure, which can simultaneously and closely contact the upper flow guiding layer and the lower conduit, efficiently capturing liquid from the flow guiding layer like a "bridge" and guiding it into the suction hole of the conduit. The cavity inside the mesh fabric can help the suction conduit evenly distribute negative pressure, avoid suction dead zones, and prevent fine fibers or SAP particles in the upper layer from directly clogging the suction hole of the conduit.

[0022] More preferably, the extraction catheter layer includes a main catheter and branch catheters, forming a distributed network of an outer ring-type main trunk and inner branches; the outer diameter of the main catheter is 3~4mm and the inner diameter is 2~3mm, and the outer diameter of the branch catheter is no greater than the height of the micro-protrusions in the liquid guiding layer, to ensure that the branch catheters can be effectively embedded or positioned in the micro-protrusion gaps of the liquid guiding layer; the diameter of the suction holes is 0.1~0.2mm, and the suction holes are arranged in a spiral staggered manner on the branch catheters with a hole spacing of 0.8~1.2mm; the material of the extraction catheter is medical-grade silicone or thermoplastic polyurethane (TPU), which has good biocompatibility, flexibility and anti-collapse properties.

[0023] Furthermore, the negative pressure connection port is connected to an anti-backflow one-way valve, with a working negative pressure of -20~-30 mmHg. The extraction conduit layer is divided into 2-3 independent suction areas, each with an independent conduit network and a negative pressure connection port. This allows for zoned suction or negative pressure adjustment based on the amount of liquid seepage or differences in location, thereby improving the adaptability and efficiency of the absorbent pad.

[0024] As a preferred embodiment, the layers of the absorbent pad are bonded together with a hydrophilic hot melt adhesive in a dot matrix or mesh pattern, with a hot melt adhesive coverage of 15-25%. The hydrophilic hot melt adhesive retains a certain degree of hydrophilicity after curing, ensuring that the liquid is not obstructed during interlayer transport. The dot matrix or mesh bonding pattern ensures the stability of the interlayer structure while maintaining sufficient gaps between layers to facilitate free liquid flow and uniform negative pressure conduction.

[0025] A second objective of this invention is to provide a method for preparing the aforementioned multilayer composite medical absorbent pad, comprising the following steps:

[0026] (1) Material preparation and pretreatment: Prepare materials for each layer, perform plasma hydrophilic treatment on the liquid guide layer and extraction conduit to improve the hydrophilicity of their surfaces and enhance the efficiency of liquid transport, and perform laser drilling on the extraction conduit.

[0027] (2) Pre-integration of the extraction conduit and the flow guide network: The extraction conduit is fixed to the integrated flow guide network by heat pressing or bonding to form a distributed network of outer ring main trunk and inner branches. This step ensures the stability of the extraction conduit network and its tight integration with the integrated flow guide network.

[0028] (3) Flow guiding layer composite: The integrated flow guiding mesh and the liquid flow guiding layer are composited by hot pressing. The micro-protrusions on the surface of the liquid flow guiding layer and the mesh of the integrated flow guiding mesh are mechanically interlocked to form a stable and efficient liquid flow guiding interface. Hydrophilic hot melt adhesive is sprayed between the layers with a dot matrix or mesh pattern to fix the two layers and further fix the structure to ensure the structural integrity under long-term use.

[0029] (4) Multilayer stacking: The liquid-permeable contact layer, the primary absorption layer, the composite flow guiding layer obtained in step (3), the liquid retention layer and the impermeable backing layer are stacked in sequence. The micro-protrusions on the surface of the liquid flow guiding layer and the micro-groove array of the primary absorption layer are used to achieve mechanical interlocking, thereby ensuring the physical positioning between each layer and the smooth flow of liquid. The layers are fixed by spraying hydrophilic hot melt adhesive with a dot matrix or mesh pattern to ensure that each layer maintains its integrity while maintaining sufficient liquid flow channels.

[0030] (5) Edge sealing and port integration: High-frequency hot pressing is performed on the laminated structure to form a strong and liquid-impermeable edge seal to prevent side leakage; the negative pressure connection port is connected to the extraction conduit and the sealing of the connection is ensured; and an airtightness test is performed to verify the sealing integrity of the extraction conduit layer and the negative pressure connection port to ensure that the negative pressure suction system can operate stably and efficiently; products that pass the airtightness test can be used as the final product.

[0031] In summary, compared with the prior art, the present invention has the following advantages and benefits:

[0032] 1. This invention, by introducing an extraction catheter layer and an external negative pressure system, completely overcomes the limitations of traditional absorbent pads' "limited, static, passive absorption and storage mechanism." This invention achieves a "continuous and dynamic liquid management mechanism," actively and continuously removing liquid from inside the absorbent pad, thereby effectively maintaining the absorbent material's absorbency, significantly extending the effective service life of the absorbent pad, reducing replacement frequency, and decreasing the generation of medical waste.

[0033] 2. The invention's ingeniously designed gradient structure of the liquid-permeable contact layer, primary absorbent layer, liquid guiding layer, and integrated guiding net work together to ensure rapid and uniform distribution of liquid within the absorbent septum and efficient guidance to the extraction conduit. This multi-layered liquid management mechanism avoids the localized saturation and uneven absorption issues common in traditional absorbent septums, maximizing the absorption capacity of the entire absorbent septum and ensuring high-throughput liquid handling capability.

[0034] 3. The negative pressure extraction mechanism of this invention can effectively reduce or even eliminate the risk of liquid backflow. Through continuous negative pressure, liquid is actively removed from the absorbent pad, thereby ensuring that the patient's skin remains dry for a long time, significantly improving patient comfort, and effectively preventing complications such as skin maceration, pressure sores, and infections. The anti-backflow one-way valve further ensures the unidirectionality of the suction process.

[0035] 4. The optimized selection of materials for each layer in the multi-layer composite structure of this invention (e.g., the downward unidirectional moisture-wicking nonwoven fabric of the liquid-permeable contact layer, the gradient distribution of SAP and wood pulp fibers in the primary absorbent layer, the liquid-guiding layer composed of a PET three-dimensional mesh spacer fabric, and the integrated guiding mesh composed of PET / Co-PET bicomponent warp-knitted mesh fabric), along with precise mechanical interlocking and hydrophilic hot melt adhesive bonding between layers, ensures the overall softness, high breathability, and excellent biocompatibility of the absorbent pad, further enhancing patient comfort and safety. The zoned aspiration area design improves the system's adaptability to different liquid exudation volumes and its ability to manage them precisely.

[0036] 5. The preparation method provided by the present invention, through precise plasma treatment, laser drilling, hot pressing composite and mechanical interlocking technology, ensures the optimization of the performance of each layer of materials and the stability and functionality of the interlayer structure, thereby ensuring the manufacturing quality and product consistency of the multilayer composite medical absorbent pad. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the multilayer composite medical absorbent pad provided in Embodiment 1 of the present invention;

[0038] Figure 2 for Figure 1 Enlarged structural diagram at point A;

[0039] Figure 3 This is a schematic diagram of the extraction catheter layer arrangement of the multilayer composite medical absorbent pad provided in Embodiment 1 of the present invention;

[0040] Figure 4 This is a schematic diagram of the extraction catheter layer arrangement of the multilayer composite medical absorbent pad provided in Embodiment 2 of the present invention;

[0041] The labels in the diagram are as follows: 1. Liquid-permeable contact layer; 2. Primary absorption layer; 3. Liquid flow guiding layer; 4. Extraction conduit layer; 4-1. Negative pressure connection port; 4-2. Branch conduit; 4-3. Main conduit; 4-4. Suction hole; 5. Liquid retention layer; 6. Impermeable backing layer; 7. Integrated flow guiding net. Detailed Implementation

[0042] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0043] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0044] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0045] The present invention will be further illustrated below with reference to specific embodiments and comparative examples.

[0046] Example 1

[0047] The multi-layer composite medical absorbent pad provided in this embodiment has a standard size of 60 cm × 90 cm, suitable for adult patient mattresses. Of course, it can also be adjusted to other sizes according to clinical needs, such as 40 cm × 60 cm for localized areas or for infants and young children. The overall thickness of the pad remains stably between 20 and 25 mm under a uniform pressure of 1 kPa, ensuring the integrity of its internal functional structure and the unobstructed flow of fluids even under pressure from the patient.

[0048] like Figures 1-2 The diagram shown is a schematic diagram of the structure of each layer of the multilayer composite medical absorbent pad provided in this embodiment. It includes a layered structure stacked from top to bottom: a liquid-permeable contact layer 1, a primary absorbent layer 2, a liquid guiding layer 3, an integrated guiding net 7, an extraction catheter layer 4, a liquid retention layer 5, and a liquid-impermeable backing layer 6.

[0049] The connection method between the primary absorption layer 2, the liquid guiding layer 3, the integrated guiding net 7, and the extraction conduit layer 4 is as follows: Figure 2 As shown, a uniform array of micro-protrusions is molded on the upper and lower surfaces of the liquid guiding layer 3. In this embodiment, the height of the micro-protrusions is 0.8 mm, and their distribution density is 25 protrusions / cm². 2The primary absorption layer 2 is conical in shape; it has a micro-groove array that matches the micro-protrusion array, thereby achieving mechanical interlocking between the primary absorption layer 2 and the liquid guiding layer 3, ensuring the physical positioning between them and the unobstructed liquid transport path. The ratio of the mesh aperture of the integrated guiding net 7 to the bottom diameter of the micro-protrusion is 0.9~1:1, ensuring that the micro-protrusions on the liquid guiding layer 3 can effectively insert into or fit the mesh of the integrated guiding net, forming a stable mechanical interlocking structure. This interlocking structure not only provides excellent interlayer bonding strength, but also forms a uniform and efficient liquid guiding interface through the precise matching of the micro-protrusions and the mesh. Figure 3 As shown, an embodiment of a distributed network consisting of a main conduit 4-3 and branch conduits 4-2 forming an outer ring-type main-inner branch network is provided. In this embodiment, the negative pressure connection port 4-1 is connected to the main conduit 4-3 and extends to the outer edge of the absorbent septum. The outer diameter of the main conduit 4-3 is 3~4 mm and the inner diameter is 2~3 mm. The outer diameter of the branch conduit 4-2 is no greater than the height of the micro-protrusions on the liquid guiding layer 3, so as to ensure that the branch conduit 4-2 can be effectively embedded or positioned in the micro-protrusion gaps on the liquid guiding layer 3. This structure can effectively prevent the branch conduit 4-2 from being squeezed and blocked by its liquid absorption hole 4-4 under the pressure of the absorbent septum.

[0050] The preparation process of the multilayer composite medical absorbent pad provided in this embodiment is as follows:

[0051] (1) Material selection and pretreatment:

[0052] a. Material selection: Based on the above technical solution, prepare all the necessary materials for each layer.

[0053] Liquid-permeable contact layer 1: As the top layer of the absorbent pad that comes into direct contact with the patient's skin, the material selection and surface treatment process of the liquid-permeable contact layer 1 are subject to strict requirements. This layer is made of a hydrophilic, highly breathable, and non-irritating composite nonwoven fabric with downward unidirectional moisture-wicking properties. In this embodiment, the composite nonwoven fabric adopts a double-layer structure design: its upper surface exhibits hydrophobic properties. In this embodiment, medical-grade polypropylene polymer fiber is used as the base material, and hexafluoropropylene is used as the precursor gas. The process is carried out in a radio frequency (RF) plasma reactor with a processing power set at 50~100W and a processing time of 60~120 seconds to form an ultra-thin fluoropolymer film with a thickness of several nanometers on the fiber surface. This film significantly improves the surface hydrophobicity, stabilizing the contact angle of water droplets on its surface between 90° and 110°, effectively preventing the upward backflow of absorbed liquid. The pore diameter of the upper surface is precisely controlled at 20-30 μm to provide appropriate resistance to prevent rapid liquid backflow while allowing a small amount of water vapor from the skin surface to escape. Conversely, the lower surface of this composite nonwoven fabric exhibits hydrophilic properties. In this embodiment, polyester fibers are impregnated with a polyoxyethylene ether nonionic surfactant (concentration of 0.5-1.0% (w / v)) at 50-60°C, followed by drying and curing to increase the hydrophilic groups on the fiber surface. After treatment, the contact angle of the lower surface can be reduced to 30-50°, ensuring that liquid can quickly penetrate downwards. The pore diameter of the lower surface is designed to be 40-60 μm, and the larger pore size is conducive to rapid capillary transport of liquid. This bilayer composite structure, transitioning from hydrophobic to hydrophilic, combined with a precisely designed gradient pore size, creates a significant capillary pressure difference. This enables efficient directional transport of liquid from the upper to the lower surface while minimizing upward backflow, ensuring the patient's skin remains consistently dry. Furthermore, this invention can also utilize a bilayer composite structure using PLA fibers (upper layer, hydrophobic, contact angle >90°) and bamboo / viscose fibers (lower layer, hydrophilic, contact angle <60°). This involves creating hydrophilic micro-lattice channels with a diameter of 50-200 μm on the PLA fibers through laser etching, followed by plasma hydrophilic treatment to reduce the surface tension to 28 mN / m. Combined with a fiber fineness of 15-25 μm, this enhances softness and skin compatibility. Therefore, the material selection for the liquid-permeable contact layer 1 follows the principles of downward unidirectional moisture wicking, hydrophilicity, high breathability, and non-irritating to the skin.

[0054] The primary absorbent layer 2, located directly below the liquid-permeable contact layer 1, primarily functions to initially and rapidly absorb and store bodily fluids, and to guide the liquid to the liquid guiding layer below through efficient capillary action. In this embodiment, a three-dimensional wood pulp cellulose web is prepared using an air-laid process, with superabsorbent polymer (SAP) particles distributed in a gradient within the web. This embodiment optimizes the design for both the fiber length of the wood pulp cellulose and the distribution of the SAP particles. Specifically, the primary absorbent layer 2 is configured with a gradient density structure comprising an upper, middle, and lower layer. Specifically: the upper layer has a SAP particle mass percentage content of 20-30% and a wood pulp fiber length of 0.5-1.0 mm; the middle layer has a SAP particle mass percentage content of 30-40% and a wood pulp fiber length of 1.5-2.0 mm; the lower layer has a SAP particle mass percentage content of 40-50% and a wood pulp fiber length of 2.5-3.0 mm; the total thickness of the primary absorbent layer is 5-10 mm. Specifically: The upper layer, adjacent to the liquid-permeable contact layer, has a lower percentage content of superabsorbent polymer (SAP) particles and shorter wood pulp fibers. This design aims to provide an extremely high initial liquid absorption rate, rapidly capturing the permeated liquid and minimizing liquid retention in the surface area to avoid saturation. The middle layer, located below the upper layer, has an increased percentage content of SAP particles and moderate wood pulp fiber length. Its main function is to act as a liquid conduction zone, utilizing the synergistic effect of fibers and SAP to efficiently and uniformly conduct liquid from the upper layer to the lower layer, while simultaneously initiating a certain degree of absorption and locking. The lower layer, adjacent to the liquid diversion layer, has an even higher percentage content of SAP particles and the longest wood pulp fibers. It is primarily responsible for achieving efficient liquid locking and buffering. Its high SAP content and the denser network formed by the cross-linking of longer fibers can deeply absorb and firmly fix a large amount of liquid, thereby significantly reducing the risk of liquid backflow to the upper layer or permeation to the lower backing layer. In this embodiment, the superabsorbent polymer is preferably a sodium polyacrylate cross-linked polymer with high absorbency and high water retention. This gradient structure ingeniously achieves a smooth functional transition from "rapid guidance" to "absorption locking," significantly improving the overall absorption efficiency and pressure resistance of the absorbent pad. Furthermore, the gradient absorption design ensures that under external pressure (such as patient weight), the upper layer, which experiences greater stress, stores relatively less liquid, effectively reducing the probability of liquid backflow to the skin surface under pressure. The primary absorbent layer also possesses sufficient structural integrity and compressive elasticity to ensure that its absorbency and liquid transport path are not significantly affected when subjected to the pressure of the patient's body.

[0055] The core function of the liquid guiding layer 3 is to uniformly guide the liquid absorbed from the primary absorption layer 2 to the extraction conduit layer 4, while providing support for the upper structure. In this embodiment, the liquid guiding layer 3 is prepared using a three-dimensional mesh spacer fabric of polyethylene terephthalate (PET), with a porosity of not less than 85%. Its interior is composed of an interconnected three-dimensional mesh structure, forming a highly efficient capillary network. This network allows the liquid permeating from the primary absorption layer 2 to be rapidly and uniformly conducted to the extraction conduit layer under the influence of gravity and the negative pressure induced by the extraction conduit layer. PET material itself possesses excellent mechanical strength, wear resistance, and creep resistance. Its outstanding compression resilience effectively prevents the upper structure from collapsing and blocking the liquid inlet of the extraction catheter layer under prolonged negative pressure or when the patient's body is under pressure, thus maintaining the long-term effectiveness of the aspiration system. To further optimize liquid transfer efficiency and the stability of the interlayer structure, the upper and lower surfaces of the liquid guiding layer 3 are uniformly molded with micro-protrusions. See the description of the connection method between the primary absorption layer 2, the liquid guiding layer 3, the integrated guiding mesh 7, and the extraction catheter layer 4 in this embodiment. These micro-protrusions not only increase the effective surface area of ​​the liquid guiding layer 3 and improve the capillary diffusion efficiency of the liquid, but also enable precise mechanical interlocking with the pre-set micro-groove array of the primary absorption layer 2 during subsequent interlayer lamination, thereby ensuring the physical positioning between layers and the unobstructed liquid transfer path. In addition, the liquid guide layer 3 also plays a role in the preliminary filtration of liquid from the primary absorption layer 2. Its mesh structure can effectively intercept or slow down the entry of larger particles (such as detached fibers or incompletely expanded SAP particles) into the extraction conduit layer 4, thereby reducing the risk of blockage of the extraction conduit 4 and ensuring the stable operation of the negative pressure suction system.

[0056] Integrated flow guiding net 7: The integrated flow guiding net 7 is strategically positioned between the liquid flow guiding layer 3 and the extraction conduit layer 4. Its core function is to act as a bridging unit for liquid transport, ensuring that liquid flows efficiently and unimpeded from the liquid flow guiding layer into the suction holes 4-4 of the extraction conduit layer 4. The integrated flow guiding net 7 is made of a two-component warp-knitted mesh fabric of polyethylene terephthalate (PET) / co-PET. This two-component material design utilizes the structural strength of PET and the low melting point of Co-PET, facilitating a strong bond with the extraction conduit during subsequent hot-pressing lamination. The mesh aperture of the mesh fabric is precisely designed, with a mesh aperture to micro-protrusion bottom diameter ratio of 0.9~1:1, ensuring that the micro-protrusions on the liquid flow guiding layer 3 can effectively insert into or fit the mesh of the integrated flow guiding net 7, forming a stable and reliable mechanical interlocking structure, thereby preventing interlayer displacement and maintaining a uniform liquid flow channel. The PET / Co-PET bicomponent warp-knitted mesh fabric possesses unique surface capillary grooves and a three-dimensional structure, enabling it to closely contact the upper liquid guiding layer 3 and the lower extraction conduit, forming a highly efficient "bridge"-like liquid transport channel. These capillary grooves are formed on the mesh surface through molding or laser etching processes, with depth and width both in the micrometer range. They assist in the spreading and directional introduction of liquid on the mesh surface through capillary forces. More importantly, the internal cavity structure of the integrated guiding mesh 7 helps achieve uniform pressure distribution under negative pressure. This avoids the formation of localized high negative pressure zones and suction dead zones near the suction holes 4-4 of the extraction conduit, ensuring uniform negative pressure and suction efficiency throughout the entire suction area, thereby optimizing liquid removal. In addition, the integrated flow guide net 7 also acts as a physical barrier. Through its precisely controlled mesh structure, it effectively prevents fine fibers or incompletely expanded water-absorbing resin particles from the primary absorbent layer 2 from directly entering and clogging the suction holes of the extraction conduit. This ensures the long-term stable operation of the negative pressure suction system, significantly extends the service life of the absorbent pad, and reduces maintenance requirements.

[0057] The extraction catheter 4, as the core component of the active liquid removal function of this invention, is made of medical-grade silicone with a hardness of 50-60. This material has excellent biocompatibility, flexibility, anti-aging properties, and anti-collapse properties, ensuring that the catheter can maintain its internal diameter under long-term continuous negative pressure aspiration without deformation leading to blockage. Its negative pressure connection port 4-1 is made of medical-grade polypropylene (PP), which integrates an anti-backflow one-way valve. The one-way valve only allows liquid to flow from inside the absorbent septum to the external collection container, effectively preventing the backflow of external liquid or air, further ensuring patient safety and system sterility. The working negative pressure range maintained by the external negative pressure generation and control system is precisely set to -20~-30 mmHg (e.g., -25 mmHg). This negative pressure value has been clinically verified and can ensure efficient liquid aspiration while avoiding discomfort, damage, or local ischemia to the patient's skin.

[0058] The liquid retention layer 5, as an important safety buffer layer, primarily provides additional water-absorbing protection in extreme situations such as temporary shutdown of the negative pressure system, sudden surges of external liquid, or localized blockage of the extraction guide tube layer. This layer is composed of a cellulose fiber-reinforced superabsorbent polymer (SAP) composite material. The cellulose fibers, such as bleached wood pulp fibers or viscose staple fibers, constitute 30-40% by mass, providing the necessary structural integrity and fiber network for the composite material. The superabsorbent polymer constitutes 60-70% by mass, preferably a sodium polyacrylate crosslinked polymer with extremely high absorbency and water retention. Its high absorbency and water retention ensure that even under pressure, large amounts of liquid can be effectively locked in, preventing it from penetrating to the bottom impermeable backing layer, thereby eliminating the risk of leakage.

[0059] Liquid-impermeable backing layer 6: As the bottom layer of the absorbent pad, its core function is to provide final leak protection, ensuring that no liquid penetrates into the external environment or the sheets. This layer is composed of a liquid-impermeable and highly flexible thin-film material. In this embodiment, a medical-grade polyethylene (PE) membrane with a thickness controlled at 30 μm is preferred. This material, while ensuring its liquid impermeability, has good puncture resistance and tensile strength, effectively resisting external physical damage. Crucially, this material possesses moisture-permeable but liquid-impermeable properties; its microporous structure allows water vapor molecules to pass through, improving the material's breathability, thereby reducing skin stuffiness and improving patient comfort. However, liquid water molecules, due to their larger size and surface tension, cannot pass through, effectively preventing liquid leakage. This moisture-permeable but liquid-impermeable property is essential for maintaining the health of the patient's skin, helping to prevent skin maceration and reducing the risk of pressure sores and infections.

[0060] b. Pretreatment: The liquid guiding layer 3 is subjected to plasma hydrophilic treatment to significantly improve its surface hydrophilicity. Specifically, a PET three-dimensional mesh spacer fabric is placed in a low-pressure plasma reaction chamber, oxygen is introduced as the working gas, and the treatment is carried out under the conditions of 100W radio frequency power, 120 seconds of processing time, and 50Pa chamber pressure, so that its surface contact angle is reduced from about 80° to below 60°, thereby enhancing the liquid transport efficiency therein.

[0061] The extraction conduit undergoes a plasma hydrophilic treatment to reduce the adhesion of liquid to its inner wall. The treatment conditions can be similar to those for a liquid flow guide layer to improve the fluidity of the liquid within the conduit. Subsequently, the extraction conduit is processed using a high-precision ultraviolet or femtosecond laser drilling device to precisely form multiple suction holes. These suction holes are precisely arranged in a spiral staggered pattern on the branch conduit, with a hole spacing of 0.8~1.2mm. The advantages of laser drilling are precise hole shape, no burrs, and a small heat-affected zone, ensuring optimal performance of the suction holes and the integrity of the conduit.

[0062] (2) Pre-integration of conduit and flow guide net:

[0063] After laser drilling, the extraction catheters are precisely fixed to predetermined positions on the integrated flow guide net 7 using a precise thermoforming bonding method. This step, employing customized molds and positioning fixtures, ensures the accurate layout of the catheter network, forming a distributed structure of an outer ring main trunk and inner branches. This pre-integration step aims to ensure the stability of the extraction catheter network and its tight bond with the integrated flow guide net 7, laying a solid foundation for subsequent liquid aspiration functions.

[0064] (3) Conveyor layer composite:

[0065] The integrated flow guiding net 7 obtained in step (2) is hot-pressed together with the liquid flow guiding layer 3 that has undergone plasma hydrophilic treatment. This allows the micro-protrusion array on the lower surface of the liquid flow guiding layer 3 to effectively insert into or fit the mesh of the integrated flow guiding net 7, achieving stable mechanical interlocking. Then, hydrophilic hot melt adhesive is precisely sprayed in a dot matrix pattern using a non-contact spraying device (nozzle diameter 0.5 mm, spraying pressure 0.2 MPa), controlling the coverage of the hot melt adhesive to about 20%, further reinforcing the two-layer structure and ensuring structural integrity and liquid transport performance under long-term use. The curing time of the hot melt adhesive is precisely controlled by a cooling roller to prevent the adhesive layer from penetrating too deeply or affecting the interlayer capillary action.

[0066] (4) Multi-layer stacking:

[0067] The liquid-permeable contact layer 1, the primary absorption layer 2, the composite flow guiding layer obtained in step (3) (i.e., the composite of the integrated flow guiding net and the liquid flow guiding layer), the liquid retention layer 5, and the impermeable backing layer 5 are stacked in a predetermined order. During the stacking process, a high-precision robot vision system is used for positioning to ensure that the micro-protrusion array on the surface of the liquid flow guiding layer 3 and the micro-groove array of the primary absorption layer 2 achieve precise mechanical interlocking. Between each functional layer, hydrophilic hot melt adhesive is also sprayed in a dot matrix pattern using a spraying equipment, with the coverage rate controlled at about 20%, to ensure that each layer maintains sufficient liquid transmission channels and air permeability while maintaining integrity.

[0068] (5) Edge sealing and port integration:

[0069] A 27.12MHz high-frequency generator with an output power of 3kW was used to seal the outer edges of all layered structures with a width of 10mm within 2 seconds, ensuring complete prevention of side leakage. The negative pressure connection port, pre-installed with an anti-backflow one-way valve, was reliably connected to the extension end of the extraction catheter, and a precise airtightness test was performed (maintaining a negative pressure of -50mmHg for 1 minute, with a leakage rate of less than 5%) to verify the sealing integrity of the connection. Finally, a rigorous overall airtightness test was conducted on the prepared multi-layer composite medical absorbent septum (the entire septum was placed in a vacuum chamber, evacuated to -30mmHg, and the pressure was observed to remain stable within 5 minutes) to verify the sealing integrity of the extraction catheter layer and the negative pressure connection port, ensuring the stable and efficient operation of the negative pressure suction system. Products that pass the airtightness test are then packaged as the final product.

[0070] The qualified product prepared in this embodiment is designated as absorbent pad 1.

[0071] Example 2

[0072] Based on Example 1, such as Figure 4 As shown, this embodiment will Figure 3 The single aspiration area shown is replaced by three independent aspiration areas, each equipped with its own catheter network and negative pressure connection port. In principle, this zoning design allows healthcare professionals to perform zoning aspiration or independently adjust the negative pressure in different areas based on the patient's fluid leakage volume, leakage site, or clinical needs, thereby significantly improving the adaptability and efficiency of the absorbent pad for refined management.

[0073] The qualified product prepared in this embodiment is designated as absorbent pad 2.

[0074] Comparative Example 1

[0075] Based on Example 1, this comparative example replaces the liquid-permeable contact layer 1 with a single layer of polyester fiber hydrophilically treated with polyoxyethylene ether nonionic surfactants, and the qualified product prepared is denoted as absorbent pad 3.

[0076] Comparative Example 2

[0077] Based on Example 1, this comparative example replaces the primary absorbent layer 2 with a composite structure of wood pulp cellulose three-dimensional fiber web composite SAP particles without a gradient density structure. The wood pulp fiber length is 1.5~2.0mm, and the SAP particle mass percentage content is 30~40%. The qualified product prepared is denoted as absorbent pad 4.

[0078] Comparative Example 3

[0079] Based on Example 1, this comparative example removes the integrated flow guide net 7, and the qualified product prepared is denoted as water-absorbing pad 5.

[0080] Experimental Example

[0081] In this experiment, the absorbent pads 1-5 prepared in Examples 1-2 and Comparative Examples 1-3 were connected to an external negative pressure generation and control system (set to negative pressure -25 mmHg) and the following tests were conducted:

[0082] Initial absorption rate (IAS): Simulated body fluid (0.9% physiological saline) was added dropwise to the central region of the septum at a flow rate of 15 mL / min, and the time it took for 10 mL of the droplet to be completely absorbed was recorded.

[0083] Total Absorbable Capacity (TAC): The total amount of liquid absorbed is recorded when the septum can no longer absorb liquid and no more liquid is extracted under continuous negative pressure suction.

[0084] Dynamic aspiration rate (DSR): The rate at which fluid is removed from the septum under steady-state conditions under continuous dripping of simulated body fluid (10 mL / min) and negative pressure aspiration of -25 mmHg.

[0085] Rewet: After the absorbent pad absorbs simulated body fluid to saturation and is aspirated for 30 minutes, a pressure of 3.5 kPa is applied to the central area for 1 minute, and the amount of liquid rewetting to the surface is measured using filter paper.

[0086] Simulated Skin Surface Humidity: By simulating a skin model and using a humidity sensor, the humidity retention of the contact layer is evaluated under continuous liquid input and suction.

[0087] Absorption Under Pressure: A pressure of 0.7 psi (approximately 4.8 kPa) was applied to the central region of the septum to simulate continuous dripping of body fluid, and the absorption efficiency was observed.

[0088] In addition, a typical commercially available disposable medical absorbent pad (without negative pressure suction function, mainly relying on SAP and fluff pulp for absorption) was selected as a control group, and the test results are shown in Table 1.

[0089] Table 1 Comparison of key performance indicators for each group of absorbent pads

[0090]

[0091] The data above clearly demonstrates that the multi-layer composite medical absorbent septum provided by this invention exhibits significant superiority in all core performance indicators. In particular, regarding total absorbency, dynamic suction rate, and rewetting, this invention, thanks to its unique negative pressure active suction system and multi-layer gradient optimized structure, achieves performance improvements unmatched by traditional absorbent septums.

[0092] Finally, it should be noted that the terms "comprising," "including," or any other variations are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make further changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0093] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A multi-layer composite absorbent pad for medical use, characterized in that, It includes a layered structure stacked from top to bottom: a liquid-permeable contact layer, a primary absorption layer, a liquid guiding layer, an integrated guiding mesh, an extraction conduit layer, a liquid retention layer, and a liquid-impermeable backing layer; The liquid-permeable contact layer is composed of a hydrophilic, highly breathable, and non-irritating composite nonwoven fabric with downward unidirectional moisture-wicking properties. The composite nonwoven fabric used to prepare the liquid-permeable contact layer includes an upper hydrophobic layer and a lower hydrophilic layer. The hydrophobic layer achieves a contact angle greater than 90° through plasma fluorocarbon finishing, and the pore diameter of the hydrophobic layer is 20~30μm. The hydrophilic layer achieves a contact angle less than 60° through nonionic surfactant finishing or plasma hydrophilic treatment, and the pore diameter of the hydrophilic layer is 40~60μm. The primary absorbent layer is a three-dimensional wood pulp cellulose web prepared by an air-flow web-forming process. Water-absorbing resin particles are distributed within the three-dimensional wood pulp cellulose web in a multi-layered gradient distribution with a sparser upper layer and a denser lower layer. The primary absorbent layer is configured with a gradient density structure comprising an upper layer, a middle layer, and a lower layer. The upper layer has a water-absorbing resin particle content of 20-30% by mass and a wood pulp fiber length of 0.5-1.0 mm; the middle layer has a water-absorbing resin particle content of 30-40% by mass and a wood pulp fiber length of 1.5-2.0 mm; the lower layer has a water-absorbing resin particle content of 40-50% by mass and a wood pulp fiber length of 2.5-3.0 mm; the total thickness of the primary absorbent layer is 5-10 mm. The liquid guiding layer is made of a material with a three-dimensional structure, high porosity, and high compressive resilience. The material of the liquid guiding layer is a PET three-dimensional mesh spacer fabric with a thickness of 6-8 mm and a porosity of not less than 85%. The upper and lower surfaces of the liquid guiding layer are uniformly molded with an array of micro-protrusions with a height of 0.5-0.8 mm, and the distribution density of the micro-protrusions is 20-30 per cm. 2 The micro-protrusions are conical or pyramidal in shape; the primary absorption layer is provided with a micro-groove array that matches the micro-protrusion array; The integrated flow guiding mesh is disposed between the liquid flow guiding layer and the extraction conduit layer to bridge the liquid between the liquid flow guiding layer and the extraction conduit layer. The integrated flow guiding mesh is a PET / Co-PET bicomponent warp-knitted mesh fabric with a mesh aperture ratio of 0.9 to 1:1 to the bottom diameter of the micro-protrusions. The extraction conduit layer includes at least one extraction conduit, which is provided with multiple liquid suction holes. One or both ends of the extraction conduit extend to the edge of the absorbent pad and are connected to a negative pressure connection port that is connected to an external negative pressure generation and control system. The liquid retention layer is composed of a water-absorbing resin composite material reinforced with cellulose fibers; The impermeable backing layer is made of a thin film material that is impermeable to liquids and has good flexibility.

2. The multi-layer composite medical absorbent pad as described in claim 1, characterized in that, The extraction catheter layer includes a main catheter and branch catheters, forming a distributed network of an outer ring-type main trunk and inner branches; the outer diameter of the main catheter is 3~4mm and the inner diameter is 2~3mm, and the outer diameter of the branch catheters is no greater than the height of the micro-protrusion of the liquid guiding layer; the diameter of the suction holes is 0.1~0.2mm, and the suction holes are arranged in a spiral staggered manner on the branch catheters with a hole spacing of 0.8~1.2mm; the material of the extraction catheter is medical-grade silicone or thermoplastic polyurethane.

3. The multi-layer composite medical absorbent pad as described in claim 2, characterized in that, The negative pressure connection port is connected to an anti-backflow one-way valve, and the working negative pressure is -20~-30mmHg. The extraction catheter layer is divided into 2-3 independent suction areas, each with an independent catheter network and negative pressure connection port.

4. The multi-layer composite medical absorbent pad as described in claim 1, characterized in that, The layers of the absorbent pad are bonded together with a hydrophilic hot melt adhesive in a dot matrix or mesh pattern, with a hot melt adhesive coverage of 15-25%.

5. The method for preparing the multilayer composite medical absorbent pad according to any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Material preparation and pretreatment: Prepare materials for each layer, perform plasma hydrophilic treatment on the liquid guide layer and the extraction guide tube, and perform laser drilling on the extraction guide tube; (2) Pre-integration of the catheter and the flow guide net: The extraction catheter is fixed to the integrated flow guide net by heat pressing or bonding; (3) Flow guiding layer composite: The integrated flow guiding net and the liquid flow guiding layer are composited by hot pressing. The micro protrusions on the surface of the liquid flow guiding layer and the mesh of the integrated flow guiding net are mechanically interlocked. Hydrophilic hot melt adhesive is sprayed between the layers in a dot matrix or mesh pattern to fix them. (4) Multilayer stacking: The liquid-permeable contact layer, the primary absorption layer, the composite flow guiding layer obtained in step (3), the liquid retention layer and the impermeable backing layer are stacked in sequence. The micro-protrusions on the surface of the liquid flow guiding layer and the micro-groove array of the primary absorption layer are used to achieve mechanical interlocking. Hydrophilic hot melt adhesive is sprayed between each layer in a dot matrix or mesh pattern to fix it. (5) Edge sealing and port integration: High-frequency hot pressing is performed on the edge sealing of the laminated structure; the negative pressure connection port is connected to the extraction catheter and an airtightness test is performed. Once the airtightness test is passed, a multi-layer composite medical absorbent pad can be obtained.

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