A pant-type absorbent article waist structure having a gradient elasticity and dynamic pressure regulating function and a method for manufacturing the same

Abstract

The application discloses a pant-type absorbent article waist structure with gradient elasticity and dynamic pressure regulation function, which comprises an inner non-woven fabric, an outer non-woven fabric and an elastic composite layer arranged between the inner non-woven fabric and the outer non-woven fabric; the elastic composite layer is divided into at least three elastic functional zones along the longitudinal direction of the waist structure; the elastic composite layer comprises a basic elastic layer and a dynamic pressure regulation layer; the dynamic pressure regulation layer is composed of a plurality of pressure regulation units; the pressure regulation units in the dynamic pressure regulation zone are unevenly distributed in the first direction of the waist structure, and the distribution density is matched with the dynamic deformation characteristics of the human abdominal part; the pressure regulation units have different extension lengths in the second direction of the waist structure. The waist structure realizes dynamic regulation of pressure self-adaption, dynamic matching of elastic gradient, functional utilization of structure deformation energy, process simplification and safety improvement, synergistic optimization of air permeability and elasticity and prolongation of product service life.

Description

Technical Field

[0001] This invention belongs to the field of hygiene products technology, specifically relating to a waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function and its preparation method. Background Technology

[0002] Pants-style absorbent products, including baby diapers, pull-ups, adult incontinence pants, and women's menstrual pants, have become core products in the modern personal hygiene field due to their convenience, comfortable fit, and excellent absorbency. The basic structure of these products typically includes a liquid-permeable top layer, an absorbent core, a liquid-impermeable bottom layer, and elastic structures around the waist and legs. The design of the waistband structure is particularly crucial, directly determining the product's dynamic fit to the wearer's body, leak-proof reliability, and long-term comfort.

[0003] With the upgrading of consumer demand, the elastic design of waistband structures has undergone a technological evolution from simple to complex, and from uniform to zoned. The first stage was a composite structure based on uniform elastic elastic bands. This stage is the most widely used basic technology, which provides circumferential contraction force for the waistband by bonding multiple parallel elastic elastic bands between two layers of non-woven fabric. Its core design idea is uniform distribution and overall contraction. To improve wearing comfort, this branch of technology developed a fine denier elastic band solution. By using fine denier elastic bands with lower denier, smaller spacing, and more individual bands, the elastic stress is transformed from point concentration to area dispersion. On this basis, a composite structure of fine denier elastic bands and elastic non-woven fabric was further proposed, attempting to achieve a balance between soft fit and anti-slip. The essential characteristic of this technological stage is that stress distribution is optimized by adjusting the physical parameters of the elastic element, but its elastic characteristics are preset and globally uniform.

[0004] The second stage involves ergonomically designed zoned elasticity and biomimetic curve structures. This stage breaks through the limitations of uniform elasticity and begins to refine the waistband design from an ergonomic perspective. For example, multiple elastic bands arranged in a smooth concave arc shape are placed in the front panel. By changing the traditional parallel straight line layout of the elastic bands to an arc curve layout, differentiated elastic zones are formed in the longitudinal direction of the waistband: the upper part near the waist opening is more elastic, the elasticity gradient decreases towards the crotch area, and an arc-shaped bulge is formed in the middle to fit the most prominent point of the lower abdomen, thereby applying micro-pressure to the user's lower abdomen. The essential feature of this technology stage is that by changing the spatial arrangement of elastic elements, a preset elastic gradient is constructed in the longitudinal direction of the waistband to optimize the pressure in specific areas, representing a technological leap from uniform elasticity to functional zoned elasticity. The third stage is an adjustable waistband based on mechanical structures. This stage attempts to give users the ability to actively adjust the tightness of the waistband. By setting elastic elements and fixing components in the back waist area, users can tighten the waistband by stretching the elastic elements or expand the waistband by unfolding the folded parts, achieving one-time adjustment. The essential feature of this technological stage is the introduction of a mechanical manual adjustment structure, which allows users to adjust the settings in discrete increments according to their own waist circumference.

[0005] From a technological development perspective, the evolution of waistband structures has progressed from uniform elasticity to zoned elasticity to manual adjustment. However, in-depth analysis reveals a common fundamental limitation in all these technological paradigms: the elastic mechanical properties of the waistband are fixed at the factory and cannot adaptively adjust to changes in the wearer's real-time physiological state or dynamic activities. Specifically, whether it's uniform elastic bands, curved elastic bands, or manually adjustable structures, the pressure-strain relationship they provide is static, preset, and unchangeable. This fundamental limitation has led to a long-standing technical challenge in the field: to ensure the product doesn't slip during strenuous activities like running and jumping, the waistband needs sufficient pre-tension. However, this pre-tension can cause pressure when the body is static or when the abdomen expands. Finding a balance between preventing slippage during dynamic activities and providing a comfortable fit in static / slowly changing states has remained a technical contradiction that those skilled in the art have yet to effectively resolve.

[0006] Based on the aforementioned technological evolution, existing technologies suffer from the following systemic defects and shortcomings.

[0007] Defect 1: Uniform mechanical response characteristics, lacking the ability to distinguish deformation rates. In existing waistband structures, whether elastic bands or elastic nonwoven fabrics, the elastic elements are rate-independent materials in terms of mechanical behavior; their stress-strain relationship is independent of the loading rate. This uniform mechanical response characteristic causes the following problems in actual use: When the wearer engages in strenuous activity causing the abdomen to expand rapidly, the waistband will be stretched instantly. Due to the lack of an instantaneous resistance cushioning mechanism, on the one hand, insufficient recoil force may cause the product to loosen or even slip off instantly; on the other hand, the sudden recoil after rapid stretching may cause impact pressure on the skin. Conversely, when the abdomen changes slowly due to eating, bloating, etc., existing waistbands cannot distinguish between rapid impacts that require cushioning and slow deformations that require adaptation, and still respond with the same mechanical mode, resulting in poor fit or a feeling of pressure.

[0008] Defect 2: The preset elastic gradient cannot adapt to the dynamic changes in the human body's physiological state. While existing technologies such as curved elastic bands create a preset longitudinal elastic gradient through spatial arrangement, this gradient is statically designed based on average group anthropometric data. However, the waist circumference varies significantly under different physiological conditions. The shape, curvature, and circumference of the abdomen dynamically change before and after meals, before and during menstruation, and in standing and sitting postures. This mismatch between the preset gradient and these dynamic changes means that the waistline cannot effectively fit when the abdomen bulges after meals, while sensitive areas of the abdomen may develop marks or experience increased discomfort due to excessive preset pressure before and after menstruation.

[0009] Defect 3: Low functional integration and ineffective utilization of structural deformation energy. Existing waistband structures only provide a single elastic restraint function. The waistband structure is constantly in a state of dynamic deformation during the wearer's daily activities. Every breath, bend, and walk causes it to undergo a stretching-retraction cycle. The energy resources contained in this continuous mechanical deformation are completely wasted in the current technology, failing to convert the dynamic deformation of the waistband into functional outputs that are beneficial to the user.

[0010] Defect 4: Discreteness and inconvenience of the adjustment mechanism. Although existing manual adjustment solutions have introduced adjustment structures, their adjustment is discrete and discontinuous. Limited adjustment levels can only be achieved through folding and unfolding or fixing parts, and continuous adjustment of any size cannot be achieved. Moreover, the adjustment process requires active user intervention. For infants or incontinent patients who cannot express their feelings, caregivers find it difficult to accurately grasp the timing and amplitude of adjustment. At the same time, the introduction of adjustment structures increases the complexity of the product structure.

[0011] Defect 5: Material selection is limited by safety and process complexity. Existing waistband elastic materials are mainly polyurethane-based spandex fibers. The solvents used in the production of these materials pose a risk of residue, and the biocompatibility of the material monomers is controversial. Furthermore, traditional spandex materials rely on external hot melt adhesives to bond with nonwoven fabrics, which increases process complexity and the risk of introducing chemical substances.

[0012] In view of this, there is an urgent need in the field for a new type of waist structure that can overcome the above limitations. Summary of the Invention

[0013] To address at least one of the aforementioned problems, this invention provides a waistband structure for trouser-type absorbent products with gradient elasticity and dynamic pressure regulation functions, and a method for preparing the same.

[0014] To achieve the above objectives, the present invention employs the following technical means: The first aspect of the present invention provides a waistband structure for a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function, comprising an inner nonwoven fabric, an outer nonwoven fabric, and an elastic composite layer sandwiched between the inner nonwoven fabric and the outer nonwoven fabric. The elastic composite layer is divided into at least three elastic functional areas along the longitudinal direction of the waist structure: the upper waist fitting area, the middle dynamic pressure adjustment area, and the lower transition connection area. The elastic composite layer includes a basic elastic layer and a dynamic pressure regulating layer. The basic elastic layer is continuously distributed in the waist-fitting area, the dynamic pressure regulating area, and the transition connection area. The dynamic pressure regulating layer is only distributed in the dynamic pressure regulating area and is composed of multiple pressure regulating units. The pressure regulating units in the dynamic pressure regulating area are non-uniformly distributed in the first direction of the waist structure, and their distribution density matches the dynamic deformation characteristics of the human abdomen. The pressure regulating units have different extension lengths in the second direction of the waist structure.

[0015] In some embodiments of the present invention, the pressure regulating units have the highest distribution density in the first direction corresponding to the rectus abdominis muscle region, with a spacing of 3 mm to 5 mm between adjacent pressure regulating units, for responding to the activity of the core abdominal region; the distribution density is moderate in the location corresponding to the external oblique muscle region, with a spacing of 5 mm to 7 mm between adjacent pressure regulating units; and the distribution density is lowest in the location corresponding to the lateral waist region, with a spacing of 7 mm to 10 mm between adjacent pressure regulating units, or only a single pressure regulating unit may be provided.

[0016] In some embodiments of the present invention, the pressure regulating unit has a shorter extension length (10 mm to 20 mm) in the second direction corresponding to the position near the waist contact area in the dynamic pressure regulating zone; a longer extension length (25 mm to 40 mm) corresponding to the position near the transition connection area; and an extension length (between the two) corresponding to the middle position, forming a dynamic pressure regulating gradient that gradually changes from the waist to the crotch in the longitudinal direction.

[0017] In some embodiments of the present invention, the first direction is the waist circumference (lateral direction), and the second direction is the waist circumference (longitudinal direction).

[0018] In some embodiments of the present invention, the pressure regulating unit is a multi-layer composite structure, which includes, from the inside out, a first encapsulation layer, a functional material layer, a second encapsulation layer and a microporous breathable layer. The first encapsulation layer is a thermoplastic polyurethane film with a thickness of 15μm to 30μm, which encapsulates the internal functional material and provides an interface bond with the basic elastic layer; The functional material layer is disposed on the first encapsulation layer and is composed of a shear thickening fluid and an elastomer substrate, wherein the mass percentage of the shear thickening fluid is 30% to 60%. The second encapsulation layer is a thermoplastic polyurethane film with a thickness of 15μm to 30μm, which, together with the first encapsulation layer, completely covers the functional material layer; The microporous breathable layer, disposed on the second encapsulation layer, is composed of polypropylene meltblown fiber with a basis weight of 5 gsm to 10 gsm and a porosity of 70% to 85%, and is used to ensure the breathability of the waistband structure and protect the internal pressure regulating unit.

[0019] In some embodiments of the present invention, the shear-thickening fluid is composed of nano-silica particles dispersed in a polyethylene glycol-based liquid, wherein the average particle size of the nano-silica particles is 100 nm to 500 nm, the particle mass percentage is 40% to 70%, and the molecular weight of the polyethylene glycol is 200 to 600. In some embodiments of the present invention, the elastomer substrate is a styrene-ethylene-butene-styrene block copolymer, the melt flow rate of which is measured to be 7 g / 10 min to 18 g / 10 min at 230°C and 2.16 kg load.

[0020] In some embodiments of the present invention, the basic elastic layer is composed of an elastic fiber web formed by meltblowing or spunbonding thermoplastic elastomer fibers with a fiber diameter of 5 μm to 20 μm and a basis weight of 15 gsm to 30 gsm.

[0021] In some embodiments of the present invention, the thermoplastic elastomer fiber is produced by melt spinning a styrene-ethylene-butene-styrene block copolymer with polypropylene at a mass ratio of 7:3 to 9:1; the styrene-ethylene-butene-styrene block copolymer has a weight-average molecular weight of 130,000 to 150,000, a styrene monomer content of 18 wt% to 31 wt%, and a melt index of polypropylene of 1000 g / 10 min to 1300 g / 10 min measured at 230°C and a load of 2.16 kg.

[0022] In some embodiments of the present invention, the basic elastic layer has gradient elasticity along the longitudinal direction of the waist structure, and its elastic modulus decreases from the waist fitting area to the transition connection area.

[0023] In some embodiments of the present invention, specifically, the elastic modulus of the waist fitting area is 3.5 N / cm to 5.0 N / cm, the elastic modulus of the dynamic pressure adjustment area is 2.0 N / cm to 3.5 N / cm, and the elastic modulus of the transition connection area is 1.0 N / cm to 2.0 N / cm.

[0024] In some embodiments of the present invention, the gradient elasticity is achieved by adjusting the mixing ratio of thermoplastic elastomer fibers and polypropylene fibers in the elastic fiber web: the mass percentage of thermoplastic elastomer fibers in the waist bonding area is 80% to 90%, in the dynamic pressure adjustment area it is 60% to 80%, and in the transition connection area it is 40% to 60%.

[0025] Each pressure regulating unit has rate-dependent mechanical response characteristics. When the wearer's abdomen deforms slowly at a rate lower than the first preset rate, the shear-thickening fluid in the pressure regulating unit remains in a low-viscosity fluid state, and the functional material layer as a whole exhibits soft and deformable characteristics, without substantially affecting the elastic response of the base elastic layer, and the waist structure maintains basic fit pressure.

[0026] When the wearer's abdomen deforms rapidly at a rate higher than the second preset rate, the shear-thickening fluid within the pressure regulating unit is subjected to high-speed shearing, causing its viscosity to increase instantaneously by two to three orders of magnitude, transforming it from a fluid state to a near-solid state. The functional material layer then exhibits rigid support characteristics. At this time, the pressure regulating unit generates instantaneous resistance opposite to the direction of deformation. Its peak resistance is positively correlated with the deformation rate; for every 10 mm / s increase in deformation rate, the peak resistance increases by 0.5 N to 1.0 N, thus achieving dynamic pressure buffering during rapid deformation.

[0027] When the deformation rate is between the first preset rate and the second preset rate, the mechanical response of the pressure regulating unit exhibits nonlinear transition characteristics, and its apparent viscosity increases continuously with the increase of the deformation rate, achieving a smooth transition from soft fit to rigid support.

[0028] In some embodiments of the present invention, a piezoelectric functional layer is further provided within part / all of the pressure regulating units of the dynamic pressure regulating layer. The piezoelectric functional layer is used to convert the mechanical energy generated by the waist structure during dynamic deformation into electrical energy and to supply power to the functional modules disposed on the waist structure.

[0029] In some embodiments of the present invention, the piezoelectric functional layer is disposed between the first encapsulation layer and the functional material layer, or between the functional material layer and the second encapsulation layer, and is composed of a piezoelectric fiber mesh.

[0030] In some embodiments of the present invention, the piezoelectric fiber web is made of polyvinylidene fluoride fiber by electrospinning, with a fiber diameter of 200 nm to 800 nm, a basis weight of 2 gsm to 8 gsm, and a piezoelectric constant d33 of 20 pC / N to 35 pC / N.

[0031] In some embodiments of the present invention, the waist structure is further provided with a functional module, which is electrically connected to the piezoelectric functional layer; the functional module includes: a micro-vibration unit composed of a miniature eccentric vibration motor; a heating unit composed of a conductive fiber mesh; and a state monitoring unit including a flexible strain sensor and a wireless communication module.

[0032] In some embodiments of the present invention, an energy storage unit is further provided between the piezoelectric functional layer and the functional module. The energy storage unit is a flexible thin-film supercapacitor, which is disposed between the elastic composite layer and the inner non-woven fabric or between the elastic composite layer and the outer non-woven fabric, and has a thickness of 0.1 mm to 0.5 mm.

[0033] The present invention also provides an interlayer composite connection structure: the inner nonwoven fabric, the basic elastic layer, the dynamic pressure regulating layer and the outer nonwoven fabric are connected by hot pressing, the hot pressing temperature is 110°C to 140°C, the hot pressing pressure is 0.2MPa to 0.5MPa and the hot pressing time is 2 seconds to 5 seconds.

[0034] During the hot-pressing process, the thermoplastic elastomer fibers in the base elastic layer partially melt under the hot-pressing temperature and pressure, forming a fusion bond with the fibers in the inner and outer nonwoven fabric layers. Simultaneously, it forms an interfacial bond with the first and second encapsulation layers of the dynamic pressure regulating layer. The thermoplastic polyurethane films of the first and second encapsulation layers form a strong fusion bond with the base elastic layer and adjacent nonwoven fabric layers under hot-pressing conditions, eliminating the need for additional adhesives.

[0035] To ensure breathability, a hot-press roller with a textured surface is used during the hot-pressing process to form dotted or grid-like hot-pressing bonding areas on the surface of the waistband structure. The spacing between adjacent hot-pressing bonding areas is 2mm to 5mm, and the area of ​​a single hot-pressing bonding area is 0.5mm² to 2.0mm², so that the hot-pressing bonding area accounts for 15% to 30% of the total area of ​​the waistband structure. This ensures good breathability while maintaining the interlayer bonding strength.

[0036] This invention also provides a method for connecting the waistband structure to the absorbent body: the waistband structure is connected to the absorbent body of the trouser-type absorbent product by ultrasonic welding or hot pressing. Specifically, the transition connection area of ​​the waistband structure extends into connecting winglets, the width of which is 15mm to 30mm and the length matches the lateral dimension of the waistband structure, and they are fixedly connected to the front and rear pieces of the absorbent body by ultrasonic welding.

[0037] The connection area between the connecting wing and the absorber body is provided with a stress dispersion structure. The stress dispersion structure consists of multiple arc-shaped grooves extending in the transverse direction of the connecting wing. The groove depth is 0.2mm to 0.5mm, and the spacing between adjacent grooves is 2mm to 4mm. This structure is used to disperse stress concentration at the connection interface between the waist structure and the absorber body, and to prevent the connection interface from peeling off during long-term use.

[0038] The present invention also provides a method for preparing the waistband structure of the trouser-type absorbent article described in the first aspect, comprising the following steps: S1. Preparation of basic elastic layer: Styrene-ethylene-butene-styrene block copolymer is blended and granulated with polypropylene in a predetermined ratio, and melt-spun at a temperature of 180°C to 230°C using a melt-blowing device to form a fiber web, with the fiber diameter controlled to be 5μm to 20μm and the basis weight to be 15gsm to 30gsm. S2. Preparation of the dynamic pressure regulating unit: First, disperse nano-silica particles in polyethylene glycol, and then prepare a shear-thickening fluid by high-speed stirring and ultrasonic dispersion, with a shear rate of 1000 s. - ¹Up to 5000s - ¹The apparent viscosity reaches 5000 mPa·s to 20000 mPa·s; then the shear-thickening fluid and the molten styrene-ethylene-butene-styrene block copolymer are blended and granulated by a twin-screw extruder at a temperature of 130°C to 160°C to obtain functional material masterbatch; the functional material masterbatch is prepared into a functional material layer with a thickness of 0.2 mm to 0.5 mm by melt extrusion molding process; finally, the functional material layer is sandwiched between the first encapsulation layer and the second encapsulation layer, and a pressure regulating unit is formed by hot pressing. S3. Assemble the elastic composite layer: Arrange the pressure regulating units on the surface of the base elastic layer according to a predetermined spacing and distribution density, and pre-fix the pressure regulating units to the base elastic layer by hot pressing or ultrasonic welding; cover the pressure regulating units with a microporous breathable layer to form a dynamic pressure regulating layer. S4, Composite Nonwoven Fabric Layer: The inner and outer nonwoven fabrics are respectively bonded to the two sides of the elastic composite layer, and the waist structure is formed by hot pressing. A hot pressing roller with a textured surface is used to form dotted or grid-like hot pressing bonding areas on the surface of the waist structure. S5. Cutting and shaping: Cut the composite waist structure to the predetermined size and heat-set it at 80℃ to 100℃ for 10 to 30 seconds.

[0039] In some embodiments of the present invention, the hot-pressing temperature in step S2 is 100°C to 120°C, and the hot-pressing pressure is 0.1 MPa to 0.3 MPa.

[0040] In some embodiments of the present invention, the hot pressing temperature in step S4 is 110°C to 140°C, and the hot pressing pressure is 0.2MPa to 0.5MPa.

[0041] All materials used in the waistband structure of this application comply with the requirements for raw material safety in GB 43631-2023 Basic Safety Technical Specifications for Paper Products for Infants and Children. The nano-silica in the shear-thickening fluid is an inorganic material, and the polyethylene glycol is a pharmaceutical-grade material with no skin irritation or sensitization. Styrene-ethylene-butene-styrene block copolymer is a thermoplastic elastomer that does not contain toxic or harmful substances and has no solvent residue. The thermoplastic polyurethane film is a medical-grade material that has passed skin irritation and cytotoxicity tests. Polypropylene meltblown fiber is a food contact grade material that meets relevant safety standards. The piezoelectric functional layer uses polyvinylidene fluoride, a biocompatible material with no cytotoxicity.

[0042] Beneficial effects of the present invention Compared with the prior art, the present invention has the following beneficial effects: This invention constructs a pressure regulating unit with a rate-dependent mechanical response by introducing a functional material layer composed of a shear-thickening fluid and an elastomer substrate into the dynamic pressure regulating layer. When the abdomen deforms slowly at a rate lower than a first preset speed (2 mm / s), the shear-thickening fluid remains in a low-viscosity fluid state, and the functional material layer remains soft and deformable, without affecting the gentle fit pressure provided by the base elastic layer, allowing the wearer to experience a static comfort without any constriction. When the abdomen deforms rapidly at a rate higher than a second preset speed (8 mm / s), the shear-thickening fluid undergoes a shear-thickening effect under high-speed shearing, with its viscosity increasing instantaneously by 2 to 3 orders of magnitude, transforming from a fluid state to a near-solid state. The functional material layer as a whole exhibits rigid support characteristics, generating instantaneous resistance opposite to the direction of deformation, with the peak resistance being positively correlated with the deformation rate. This rate-dependent mechanical response mechanism allows the waistband to stiffen during rapid deformation to provide instantaneous support and prevent slippage, while remaining soft during slow deformation to adapt to a close fit, thus resolving the technical contradiction between static comfort and dynamic fit.

[0043] This invention employs a non-uniform distribution of pressure-regulating units in the dynamic pressure-regulating layer along the lateral direction of the waist circumference: the highest density is set in the region corresponding to the rectus abdominis muscle, a medium density in the external oblique muscle region, and the lowest density in the lateral waist region. This ensures that the elastic response characteristics of the waist circumference precisely match the dynamic deformation characteristics of different regions of the human body. Simultaneously, the pressure-regulating units have varying extension lengths along the longitudinal direction: units closer to the waist contact area extend shorter, while units closer to the transition connection area extend longer, thus creating an adaptive pressure-regulating gradient that gradually changes from the waist to the groin. This non-uniform distribution design, matching the dynamic deformation characteristics of the human body, enhances the elastic adjustment capability of the waist circumference from a preset static gradient to a dynamic adaptive gradient.

[0044] This invention, by incorporating a piezoelectric functional layer within at least a portion of the pressure regulating units of the dynamic pressure regulating layer, converts the mechanical energy generated during the dynamic deformation of the waistband structure into electrical energy, supplying power to functional modules mounted on the waistband structure. By storing this electrical energy using a flexible thin-film supercapacitor, various additional functions can be achieved: driving a micro-eccentric vibration motor to generate micro-vibrations, providing massage stimulation to the wearer's abdomen to promote blood circulation; driving a conductive fiber mesh to generate heat, providing a heat therapy function to the wearer's abdomen to alleviate menstrual discomfort; and driving a flexible strain sensor and wireless communication module to monitor the waistband's deformation state and transmit status signals. This integrated functional design upgrades the waistband from a passive restraint element to an active functional carrier, fully exploiting and utilizing system resources and significantly enhancing the product's added value.

[0045] The basic elastic layer of this invention is made by melt spinning a styrene-ethylene-butene-styrene block copolymer with polypropylene at a mass ratio of 7:3 to 9:1. This material can partially melt under hot-pressing conditions of 110℃-140℃, forming a melt bond with the fibers in the inner and outer nonwoven fabrics. The first and second encapsulation layers of the dynamic pressure regulating unit are made of thermoplastic polyurethane film, which also forms a strong interfacial bond with the basic elastic layer and adjacent nonwoven fabric layers under hot-pressing conditions. This melt bonding mechanism completely eliminates the step of applying hot melt adhesive in traditional processes, achieving adhesive-free composite. On the one hand, it simplifies the production process and reduces costs; on the other hand, it eliminates the safety hazards such as chemical odor and skin irritation that adhesives may cause. At the same time, the styrene-ethylene-butene-styrene block copolymer used in this invention is a thermoplastic elastomer, which does not contain toxic or harmful substances and has no solvent residue, meeting the requirements of GB 43631-2023 regarding the safety of raw materials.

[0046] The basic elastic layer of this invention adopts a fiber mesh structure, which has good air permeability. A microporous breathable layer, composed of polypropylene meltblown fibers with a porosity of 70%-85%, is provided above the second encapsulation layer of the dynamic pressure regulating unit, further ensuring unobstructed airflow channels. During the hot-pressing process, a hot-pressing roller with a textured surface is used to form dotted or grid-like hot-pressing bonding areas. These bonding areas account for only 15%-30% of the total area of ​​the waistband structure, maximizing the airflow channel area. This multi-layered breathable design allows the waistband structure of this invention to provide gradient elasticity while maintaining excellent breathability, achieving an air permeability of over 350 ft³ / ft² / min, far superior to traditional elastic membrane waistbands, thus resolving the contradiction between high elasticity requirements and breathability.

[0047] The waist structure of this invention extends connecting winglets in the transition connection area. The connection area between the connecting winglets and the absorbent body is equipped with a stress-dispersing structure: multiple arc-shaped grooves extending laterally, with a groove depth of 0.2mm-0.5mm and a spacing of 2mm-4mm between adjacent grooves. This effectively disperses stress concentration at the connection interface, preventing peeling during long-term use. Simultaneously, the gradient elastic design of the base elastic layer makes the stress distribution more rational: the waist-fitting area provides strong binding force to ensure anti-detachment, the dynamic pressure adjustment area provides moderate support force, and the transition connection area provides less connecting force, ensuring that the stress level in each area matches the functional requirements. This stress-optimized design, on the one hand, extends the effective service life of the product, and on the other hand, allows for a reduction in material usage while maintaining performance, resulting in significant economic and environmental benefits.

[0048] All materials used in the waistband structure of this invention comply with the requirements for raw material safety in GB 43631-2023 Basic Safety Technical Specifications for Paper Products for Infants and Children: the nano-silica in the shear-thickening fluid is an inorganic material; polyethylene glycol is a pharmaceutical-grade material; the styrene-ethylene-butene-styrene block copolymer is a thermoplastic elastomer that does not contain toxic or harmful substances; the thermoplastic polyurethane film is a medical-grade material; and the polypropylene meltblown fiber is a food-contact grade material. The hygiene indicators of all materials and the composite structure comply with the provisions of GB 15979-2024 Hygienic Requirements for Disposable Sanitary Products, including initial contamination bacteria, total bacterial count, coliform bacteria, pathogenic pyogenic bacteria, and total fungal count. The dimensional stability, elastic recovery rate, and breathability of the waistband structure comply with the relevant provisions of GB / T 28004.1-2021 Diapers Part 1: Baby Diapers. The waistband structure of this invention can be produced using existing hygiene product manufacturing equipment without large-scale equipment modification. The process is clear and controllable, and it has good prospects for industrialization. Attached Figure Description

[0049] Figure 1 This is a top view of the unfolded state of the waist structure in Embodiment 1 of the present invention; Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure along the AA direction; Figure 3 This is a cross-sectional view of the dynamic pressure regulating unit in Embodiment 1 of the present invention; Figure 4 This is a partial cross-sectional schematic diagram of the connection state between the waist structure and the absorbent body in Embodiment 1 of the present invention; Figure 5 This is a partial cross-sectional view of the piezoelectric functional layer integrated into the waist structure in Embodiment 3 of the present invention; The area is divided into three sections: I. Waist support zone; II. Dynamic pressure adjustment zone; III. Transition connection zone. 1. Inner non-woven fabric; 2. Outer non-woven fabric; 3. Elastic composite layer; 31. Basic elastic layer; 32. Dynamic pressure regulating layer; 321. Pressure regulating unit; 3211. First encapsulation layer; 3212. Functional material layer; 3213. Second encapsulation layer; 3214. Microporous breathable layer; 4. Absorbent core; 5. Connecting wing; 6. Stress dispersion structure; 7. Piezoelectric functional layer; 8. Functional module; 81. Micro-vibration unit; 82. Heating unit; 83. Status monitoring unit; 9. Energy storage unit. Detailed Implementation

[0050] The following examples are used to illustrate preferred embodiments of the invention. Those skilled in the art will understand that the techniques disclosed in the examples represent techniques discovered by the inventors that can be used to implement the invention, and therefore can be considered preferred embodiments for implementing the invention. However, those skilled in the art should understand from this specification that many modifications can be made to the specific embodiments disclosed herein, still yielding the same or similar results, without departing from the spirit or scope of the invention.

[0051] 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, and all materials disclosed herein are incorporated herein by reference. Many equivalent techniques of specific embodiments of the invention described herein will be recognized or can be understood by those skilled in the art through conventional experimentation. These equivalents will be included in the claims.

[0052] The technical solution of this application will be further described in detail below with reference to specific embodiments.

[0053] Example 1: Overall Construction of the Waist Circumference Structure This embodiment provides a waistband structure for a trouser-type absorbent product with gradient elasticity and dynamic pressure adjustment functions. The overall structure is arc-shaped and is used to connect with the absorbent body of the trouser-type absorbent product to form a complete waistband system. The waistband structure is divided into three elastic functional zones along its longitudinal direction (i.e., the direction extending from the waist to the crotch when worn): the upper waist-fitting zone (Ⅰ), the middle dynamic pressure adjustment zone (Ⅱ), and the lower transition connection zone (Ⅲ).

[0054] The longitudinal width of the waist-fitting area (Ⅰ) is 25mm to 35mm, which is used to fit the uppermost part of the wearer's waist and provide the main anti-slip restraint force.

[0055] The dynamic pressure adjustment zone (II) has a longitudinal width of 40mm to 60mm and is used to cover the main active area of ​​the wearer's abdomen, providing adaptive dynamic pressure adjustment.

[0056] The longitudinal width of the transition connection zone (Ⅲ) is 15mm to 25mm, used to connect with the absorber body and form a stress buffer transition. A partial sectional view of the connection state between the waist structure and the absorber body is shown below. Figure 4 As shown.

[0057] The waistband structure includes an inner nonwoven fabric (1), an outer nonwoven fabric (2), and an elastic composite layer (3) sandwiched between the inner nonwoven fabric (1) and the outer nonwoven fabric (2). The unfolded state diagram of the waistband structure is shown below. Figure 1As shown. The inner nonwoven fabric (1) is a hydrophilic hot-air nonwoven fabric with a basis weight of 15 gsm to 20 gsm, used on the side facing the wearer's skin to provide a soft touch and comfort. The outer nonwoven fabric (2) is a hydrophobic spunbond nonwoven fabric with a basis weight of 12 gsm to 18 gsm, used on the side facing the garment to provide abrasion resistance and a smooth appearance.

[0058] Example 2: Specific Structure of the Elastic Composite Layer A partial sectional view of the waist structure along the AA direction is shown below. Figure 2 As shown.

[0059] The elastic composite layer (3) includes a basic elastic layer (31) and a dynamic pressure regulating layer (32). The basic elastic layer (31) is continuously distributed in the waist-fitting area (Ⅰ), the dynamic pressure regulating area (Ⅱ), and the transition connection area (Ⅲ), providing basic fitting pressure. The dynamic pressure regulating layer (32) is only distributed in the dynamic pressure regulating area (Ⅱ) and is spaced along the transverse direction of the waist structure, used to automatically adjust the local support force in response to the dynamic changes in the abdominal deformation rate.

[0060] The basic elastic layer (31) is composed of an elastic fiber web, which is made by melt spinning a blend of styrene-ethylene-butene-styrene block copolymer (SEBS) and polypropylene (PP) at a mass ratio of 8:2. The SEBS has a weight-average molecular weight of 142,000 and a styrene monomer content of 25 wt%; the melt index of PP was measured at 230°C and a load of 2.16 kg to be 1200 g / 10 min. The fiber diameter of the elastic fiber web is 10 μm to 15 μm, and the basis weight is 22 gsm. The basic elastic layer (31) has gradient elasticity along the longitudinal direction of the waist structure, which is achieved by adjusting the mixing ratio of SEBS and PP in the elastic fiber network: the mass percentage of SEBS in the waist bonding area (Ⅰ) is 85%, and the elastic modulus is 4.2 N / cm; the mass percentage of SEBS in the dynamic pressure adjustment area (Ⅱ) is 70%, and the elastic modulus is 2.8 N / cm; the mass percentage of SEBS in the transition connection area (Ⅲ) is 50%, and the elastic modulus is 1.5 N / cm.

[0061] The dynamic pressure regulating layer (32) is composed of multiple pressure regulating units (321), and the cross-sectional view of the dynamic pressure regulating unit is shown below. Figure 3As shown, each pressure regulating unit (321) is arranged non-uniformly along the transverse direction of the waist structure. Each pressure regulating unit (321) is a multi-layer composite structure, which includes, from the inside out: a first encapsulation layer (3211), which is a thermoplastic polyurethane film with a thickness of 20 μm; a functional material layer (3212), which is disposed on the first encapsulation layer (3211) with a thickness of 0.3 mm; a second encapsulation layer (3213), which is a thermoplastic polyurethane film with a thickness of 20 μm, which together with the first encapsulation layer (3211) completely covers the functional material layer (3212); and a microporous breathable layer (3214), which is disposed on the second encapsulation layer (3213), and is made of polypropylene meltblown fiber with a basis weight of 8 gsm and a porosity of 78%.

[0062] The functional material layer (3212) is composed of a shear-thickening fluid and a SEBS elastomer substrate, wherein the shear-thickening fluid comprises 45% by mass. The shear-thickening fluid consists of nano-silica particles dispersed in a polyethylene glycol-based liquid. The average particle size of the nano-silica particles is 200 nm, and the particle mass percentage is 60%. The molecular weight of the polyethylene glycol is 400. The melt flow rate of the SEBS elastomer substrate was measured to be 12 g / 10 min at 230 °C and a load of 2.16 kg.

[0063] Example 3: Distribution Design of Pressure Regulating Units The pressure regulating units (321) within the dynamic pressure regulating zone (II) are non-uniformly distributed in the transverse direction of the waist structure, and their distribution density matches the dynamic deformation characteristics of the human abdomen. Specifically: In the region corresponding to the rectus abdominis muscle in the human body ( Figure 1 In the middle area B), the distribution density of pressure regulating units (321) is the highest, the spacing between adjacent pressure regulating units (321) is 4 mm, and a total of 12 pressure regulating units are set; In the region corresponding to the external oblique muscle of the human abdomen ( Figure 1 In the middle region C), the distribution density of pressure regulating units (321) is moderate, the spacing between adjacent pressure regulating units (321) is 6 mm, and a total of 8 pressure regulating units are set. In the area corresponding to the side waist of the human body ( Figure 1 In the middle region D), the distribution density of pressure regulating units (321) is the lowest, the spacing between adjacent pressure regulating units (321) is 8 mm, and a total of 4 pressure regulating units are set.

[0064] Each pressure regulating unit (321) has a different extension length in the longitudinal direction of the waist structure. In the dynamic pressure regulating zone (II), the pressure regulating unit (321) near the waist fitting zone (I) has an extension length of 15 mm; the pressure regulating unit (321) near the transition connection zone (III) has an extension length of 30 mm; and the extension length of the middle pressure regulating unit (321) is gradually distributed between 20 mm and 25 mm.

[0065] Example 4: Composite and Connecting Structure Between Layers The inner nonwoven fabric (1), the basic elastic layer (31), the dynamic pressure regulating layer (32), and the outer nonwoven fabric (2) are joined together by hot pressing. The hot pressing temperature is 125℃, the hot pressing pressure is 0.35MPa, and the hot pressing time is 3 seconds.

[0066] During the hot-pressing process, the SEBS / PP composite fibers in the base elastic layer (31) partially melt under the hot-pressing temperature and pressure, forming a fusion bond with the fibers in the inner nonwoven fabric (1) and the outer nonwoven fabric (2), and simultaneously forming an interfacial bond with the first encapsulation layer (3211) and the second encapsulation layer (3213) of the dynamic pressure regulating layer (32). The thermoplastic polyurethane film of the first encapsulation layer (3211) and the second encapsulation layer (3213) forms a strong fusion bond with the base elastic layer (31) and the adjacent nonwoven fabric layer under hot-pressing conditions, without the need for additional adhesives.

[0067] To ensure breathability, a textured hot-press roller is used during the hot-pressing process to create dotted hot-pressing bonding areas on the surface of the waistband structure. These bonding areas are circular with a diameter of 1.0 mm, and the spacing between adjacent bonding areas is 3 mm. The hot-pressing bonding areas account for 22% of the total area of ​​the waistband structure.

[0068] Example 5: Connection method between the waist structure and the absorbent body The waistband structure is connected to the absorbent body (4) of the trouser-type absorbent product via ultrasonic welding. Specifically, the transition connection area (Ⅲ) of the waistband structure extends into a connecting wing (5). The connecting wing (5) is 20 mm wide and its length matches the lateral dimension of the waistband structure. It is fixedly connected to the front and rear pieces of the absorbent body (4) via ultrasonic welding. The ultrasonic welding frequency is 22 kHz, the welding pressure is 0.25 MPa, and the welding time is 0.5 seconds.

[0069] A stress dispersion structure (6) is provided in the connection area between the connecting wing (5) and the absorption body (4). The stress dispersion structure (6) consists of multiple arc-shaped grooves extending in the transverse direction of the connecting wing (5). The groove depth is 0.3 mm and the spacing between adjacent grooves is 3 mm. It is used to disperse the stress concentration at the connection interface between the waist structure and the absorption body (4) and prevent the connection interface from peeling off during long-term use.

[0070] Example 6: Preparation method of waist structure The waist structure in this embodiment is prepared using the following method: Step 1: Preparation of the basic elastic layer. SEBS and PP are blended and granulated at a mass ratio of 8:2, and then melt-spun at 210℃ using a meltblown equipment to form a fiber web. The fiber diameter is controlled at 12μm and the basis weight at 22gsm. During the meltblown process, the distance between the receiving device and the spinneret and the airflow velocity are adjusted to ensure that the fiber web has a uniform pore structure.

[0071] Step 2: Preparation of the dynamic pressure regulating unit. First, nano-sized silica particles with an average particle size of 200 nm and polyethylene glycol with a molecular weight of 400 were mixed at a mass ratio of 60:40. The mixture was then subjected to high-speed stirring (3000 r / min, 30 min) and ultrasonic dispersion (500 W, 20 min) to prepare a shear-thickening fluid with a shear rate of 3000 s⁻¹. - ¹The apparent viscosity is 12000 mPa·s; secondly, the shear-thickening fluid and molten SEBS are blended and granulated at 150°C using a twin-screw extruder to obtain functional material masterbatch; thirdly, the functional material masterbatch is extruded at 160°C using a melt extrusion molding process, and then cooled and shaped to form a functional material layer with a thickness of 0.3 mm; finally, the functional material layer is sandwiched between the first encapsulation layer and the second encapsulation layer, and a pressure regulating unit is formed by hot pressing, with a hot pressing temperature of 110°C and a hot pressing pressure of 0.2 MPa.

[0072] Step 3: Assemble the elastic composite layer. Arrange the pressure regulating units on the surface of the base elastic layer according to a predetermined spacing and distribution density. Pre-fix the pressure regulating units to the base elastic layer by ultrasonic welding. The ultrasonic power is 50W and the welding time is 0.2 seconds. Cover the pressure regulating units with a microporous breathable layer to form a dynamic pressure regulating layer.

[0073] Step 4: Composite Nonwoven Fabric Layer. The inner and outer nonwoven fabric layers are respectively bonded to both sides of the elastic composite layer, and the waistband structure is formed by hot pressing. The hot pressing temperature is 125℃ and the hot pressing pressure is 0.35MPa. A hot pressing roller with a concave-convex texture is used to form dotted hot pressing bonding areas on the surface of the waistband structure.

[0074] Step 5: Cutting and Shaping. Cut the composite waistband structure to the predetermined size and heat-set it at 90℃ for 20 seconds to eliminate internal stress and ensure dimensional stability.

[0075] Example 7: Energy Conversion and Functional Integration Structure of Waist Circumference The waist structure, based on Embodiment 1, adds an energy conversion and functional integration structure, such as... Figure 5 As shown.

[0076] Within at least a portion of the pressure regulating unit of the dynamic pressure regulating layer, a piezoelectric functional layer (7) is also provided. The piezoelectric functional layer (7) is disposed between the first encapsulation layer (3211) and the functional material layer (3212), and is composed of a piezoelectric fiber mesh. The piezoelectric fiber mesh is made of polyvinylidene fluoride fiber by electrospinning process, with a fiber diameter of 500 nm, a basis weight of 5 gsm, and a piezoelectric constant d33 of 28 pC / N.

[0077] The piezoelectric functional layer (7) is electrically connected to the functional module (8) disposed on the waist structure. The functional module (8) includes a micro-vibration unit (81), a heating unit (82), and a status monitoring unit (83). The micro-vibration unit (81) is composed of a miniature eccentric vibration motor and is disposed in the side waist area of ​​the waist structure; the heating unit (82) is composed of a conductive fiber mesh and is disposed in the front abdominal area of ​​the waist structure; the status monitoring unit (83) includes a flexible strain sensor and a wireless communication module and is disposed in the dynamic pressure adjustment area.

[0078] An energy storage unit (9) is provided between the piezoelectric functional layer (7) and the functional module. The energy storage unit (9) is a flexible thin-film supercapacitor, which is located between the elastic composite layer (3) and the inner non-woven fabric (1) and has a thickness of 0.3 mm. The energy storage unit (9) is used to store the electrical energy generated by the piezoelectric functional layer (7) during the dynamic deformation of the waist structure and to supply power to the functional module when needed.

[0079] When the wearer performs daily activities, the waist structure deforms continuously with abdominal movement. The piezoelectric functional layer (7) converts the deformation mechanical energy into electrical energy, which is stored in the energy storage unit (9). When the energy storage unit (9) reaches a preset threshold, it can drive the micro-vibration unit (81) to generate micro-vibrations with a frequency of 50Hz to 100Hz, providing massage stimulation to the wearer's abdomen and promoting local blood circulation; or drive the heating unit (82) to generate warmth of 38°C to 42°C, providing a hot compress function to the wearer's abdomen and relieving menstrual discomfort; the status monitoring unit (83) continuously monitors the deformation status of the waist structure and sends status signals to the outside through the wireless communication module, which can be used for remote monitoring or product usage status recording.

[0080] The mechanical response mechanism of the pressure regulating unit in the waist structure of this application is as follows: When the wearer's abdomen deforms slowly at a rate lower than the first preset rate (e.g., the waist circumference increases slowly at a rate of 0.5 mm / s), the shear-thickening fluid within the pressure regulating unit remains in a low-viscosity state (apparent viscosity approximately 2000 mPa·s). The functional material layer as a whole exhibits soft and deformable properties, having no substantial impact on the elastic response of the base elastic layer. At this time, the base elastic layer of the waistband structure provides the main elastic recoil force, and the pressure regulating unit deforms along with the base elastic layer, resulting in a gentle, close-fitting pressure that is not oppressive on the wearer.

[0081] When the wearer's abdomen deforms rapidly at a rate higher than the second preset rate (e.g., the waist circumference increases instantaneously at a rate of 15 mm / s during running and jumping), the shear-thickening fluid within the pressure regulating unit is subjected to high-speed shearing, causing the viscosity to increase instantaneously to approximately 15000 mPa·s, transforming from a fluid state to a near-solid state. The functional material layer as a whole exhibits rigid support characteristics. At this time, the pressure regulating unit generates an instantaneous resistance F opposite to the direction of deformation. Its peak resistance is positively correlated with the deformation rate; for every 10 mm / s increase in deformation rate, the peak resistance increases by 0.5-1.0 N. This instantaneous resistance provides instantaneous support during rapid abdominal expansion, preventing the waist circumference from being overstretched and causing the product to slip; and provides cushioning during rapid retraction, avoiding impact pressure on the skin caused by elastic recoil force.

[0082] When the deformation rate is between the first preset rate (2 mm / s) and the second preset rate (8 mm / s), the mechanical response of the pressure regulating unit exhibits non-linear transition characteristics. Its apparent viscosity increases continuously with the increase of the deformation rate, achieving a smooth transition from soft fit to rigid support, so that the wearer will not feel any abrupt mechanical changes.

[0083] The material safety and standard compliance of the waist structure of the present invention were verified, and the results are as follows: (a) Raw material safety verification Tests were conducted according to GB 43631-2023 Basic Safety Technical Specifications for Paper Products for Infants and Children: Nano-silica in shear-thickening fluids: The contents of heavy metals lead, arsenic, mercury, and cadmium were all below the detection limit (detection limit 0.1 mg / kg). Polyethylene glycol, ethylene oxide and dioxane residues in shear-thickened fluids were both below the detection limit (detection limit 1 mg / kg). SEBS elastomer: styrene monomer residue is below the detection limit (0.5 mg / kg), and there is no diphenylmethane diisocyanate residue; Thermoplastic polyurethane film: skin irritation score average 0.2 (non-irritating), cytotoxicity rating grade 0 (no cytotoxicity); Polypropylene meltblown fiber: Passed food contact material safety test, with total migration amount less than 2mg / dm².

[0084] (II) Verification of health indicators Tests were conducted according to GB 15979-2024, "Hygienic Requirements for Disposable Sanitary Products". Initial contamination bacteria: ≤100 CFU / g; Total bacterial count: ≤20 CFU / g; Coliform bacteria: Not detected; Staphylococcus aureus: Not detected; Hemolytic streptococci: Not detected; Total fungal colony count: Not detected.

[0085] (III) Performance Index Verification Tests were conducted according to GB / T 28004.1-2021 Diapers Part 1: Baby Diapers: Waist circumference stability: After 5 stretching and shrinking cycles, the dimensional change rate is ≤3%; Elastic recovery rate: After being stretched to 150% of its original length, the shrinkage rate is ≥92%; Air permeability: 350 ft³ / ft² / min to 450 ft³ / ft² / min; Peel strength: The peel strength between the inner non-woven fabric and the elastic composite layer is ≥0.8N / 25mm; Pressure distribution uniformity: The coefficient of variation of pressure in each area of ​​the waist circumference is ≤15%.

[0086] In summary, this invention, by constructing a rate-dependent dynamic pressure regulation mechanism, a non-uniformly distributed pressure regulation unit array, a piezoelectric integrated energy recovery system, a glue-free composite fusion bonding structure, a multi-layered breathable channel design, and a stress dispersion structure, systematically solves the defects of existing technologies while achieving adaptive dynamic pressure regulation, dynamic matching of elastic gradients, functional utilization of structural deformation energy, simplified process and improved safety, synergistic optimization of breathability and elasticity, and extended product lifespan. It provides a novel waistband structure for trouser-style absorbent products that combines excellent dynamic fit performance, high wearing comfort, multi-functional integration, simple process, safe materials, and compliance with national standards, possessing promising industrialization prospects.

[0087] All documents mentioned in this invention are incorporated herein by reference as if each document were individually incorporated by reference. Furthermore, it should be understood that after reading the foregoing teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by this application.

Claims

1. A waistband structure for trouser-style absorbent products with gradient elasticity and dynamic pressure regulation, characterized in that: It includes an inner nonwoven fabric, an outer nonwoven fabric, and an elastic composite layer sandwiched between the inner and outer nonwoven fabrics; The elastic composite layer is divided into at least three elastic functional areas along the longitudinal direction of the waist structure: the upper waist fitting area, the middle dynamic pressure adjustment area, and the lower transition connection area. The elastic composite layer includes a basic elastic layer and a dynamic pressure regulating layer. The basic elastic layer is continuously distributed in the waist-fitting area, the dynamic pressure regulating area, and the transition connection area. The dynamic pressure regulating layer is only distributed in the dynamic pressure regulating area and is composed of multiple pressure regulating units. The pressure regulating units in the dynamic pressure regulating area are non-uniformly distributed in the first direction of the waist structure, and their distribution density matches the dynamic deformation characteristics of the human abdomen. The pressure regulating units have different extension lengths in the second direction of the waist structure.

2. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 1, characterized in that: The pressure regulating units have the highest distribution density in the first direction corresponding to the rectus abdominis muscle region, with a spacing of 3mm to 5mm between adjacent pressure regulating units; the distribution density is moderate in the region corresponding to the external oblique muscle region, with a spacing of 5mm to 7mm between adjacent pressure regulating units; and the distribution density is lowest in the region corresponding to the lateral waist region, with a spacing of 7mm to 10mm between adjacent pressure regulating units, or only a single pressure regulating unit may be provided.

3. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 1, characterized in that: The pressure regulating unit has a shorter extension length (10mm to 20mm) in the dynamic pressure regulating zone near the waist contact area in the second direction; a longer extension length (25mm to 40mm) in the zone near the transition connection area; and an extension length (between the two) in the middle position, forming a dynamic pressure regulating gradient that gradually changes from the waist to the crotch in the longitudinal direction.

4. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 1, characterized in that: The pressure regulating unit is a multi-layer composite structure, which includes, from the inside out, a first encapsulation layer, a functional material layer, a second encapsulation layer, and a microporous breathable layer. The first encapsulation layer is a thermoplastic polyurethane film with a thickness of 15μm to 30μm, which encapsulates the internal functional material and provides an interface bond with the basic elastic layer; The functional material layer is disposed on the first encapsulation layer and is composed of a shear thickening fluid and an elastomer substrate, wherein the mass percentage of the shear thickening fluid is 30% to 60%. The second encapsulation layer is a thermoplastic polyurethane film with a thickness of 15μm to 30μm, which, together with the first encapsulation layer, completely covers the functional material layer; The microporous breathable layer, disposed on the second encapsulation layer, is composed of polypropylene meltblown fiber with a basis weight of 5 gsm to 10 gsm and a porosity of 70% to 85%, and is used to ensure the breathability of the waistband structure and protect the internal pressure regulating unit.

5. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 4, characterized in that: The shear-thickening fluid is composed of nano-silica particles dispersed in a polyethylene glycol-based liquid. The average particle size of the nano-silica particles is 100 nm to 500 nm, the particle mass percentage is 40% to 70%, and the molecular weight of the polyethylene glycol is 200 to 600.

6. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 5, characterized in that: The elastomer substrate is a styrene-ethylene-butene-styrene block copolymer, and its melt flow rate was measured to be 7 g / 10 min to 18 g / 10 min at 230 °C and 2.16 kg load.

7. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 1, characterized in that: The basic elastic layer is composed of an elastic fiber web, which is formed by thermoplastic elastomer fibers through meltblowing or spunbonding processes. The fiber diameter is 5μm to 20μm and the basis weight is 15gsm to 30gsm.

8. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 7, characterized in that: The thermoplastic elastomer fiber is produced by melt spinning a styrene-ethylene-butene-styrene block copolymer with polypropylene at a mass ratio of 7:3 to 9:

1. The styrene-ethylene-butene-styrene block copolymer has a weight-average molecular weight of 130,000 to 150,000, a styrene monomer content of 18 wt% to 31 wt%, and a melt index of polypropylene of 1000 g / 10 min to 1300 g / 10 min at 230°C and a load of 2.16 kg.

9. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 7, characterized in that: The basic elastic layer has gradient elasticity along the longitudinal direction of the waist structure, and its elastic modulus decreases from the waist fitting area to the transition connection area.

10. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 9, characterized in that: The gradient elasticity is achieved by adjusting the mixing ratio of thermoplastic elastomer fibers and polypropylene fibers in the elastic fiber network: the mass percentage of thermoplastic elastomer fibers in the waist bonding area is 80% to 90%, in the dynamic pressure adjustment area it is 60% to 80%, and in the transition connection area it is 40% to 60%.

11. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 1, characterized in that: The dynamic pressure regulation layer also includes a piezoelectric functional layer within some or all of its pressure regulation units.

12. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 11, characterized in that: The piezoelectric functional layer is disposed between the first encapsulation layer and the functional material layer, or between the functional material layer and the second encapsulation layer, and is composed of a piezoelectric fiber mesh.

13. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 11, characterized in that: The waist structure is also equipped with functional modules, which are electrically connected to the piezoelectric functional layer. The functional modules include: a micro-vibration unit composed of a miniature eccentric vibration motor; a heating unit composed of a conductive fiber mesh; and a status monitoring unit containing a flexible strain sensor and a wireless communication module.

14. The waistband structure of a trouser-type absorbent product with gradient elasticity and dynamic pressure regulation function according to claim 13, characterized in that: An energy storage unit is also provided between the piezoelectric functional layer and the functional module. The energy storage unit is a flexible thin-film supercapacitor. The flexible thin-film supercapacitor is disposed between the elastic composite layer and the inner non-woven fabric or between the elastic composite layer and the outer non-woven fabric, and has a thickness of 0.1 mm to 0.5 mm.

15. The method for preparing the waistband structure of the trouser-type absorbent product according to any one of claims 1-14, characterized in that, Includes the following steps: S1. Preparation of basic elastic layer: Styrene-ethylene-butene-styrene block copolymer is blended and granulated with polypropylene in a predetermined ratio, and melt-spun at a temperature of 180°C to 230°C using a melt-blowing device to form a fiber web, with the fiber diameter controlled to be 5μm to 20μm and the basis weight to be 15gsm to 30gsm. S2. Preparation of the dynamic pressure regulating unit: First, disperse nano-silica particles in polyethylene glycol, and then prepare a shear-thickening fluid by high-speed stirring and ultrasonic dispersion, with a shear rate of 1000 s. - ¹Up to 5000s - ¹The apparent viscosity reaches 5000 mPa·s to 20000 mPa·s; then the shear-thickening fluid and the molten styrene-ethylene-butene-styrene block copolymer are blended and granulated by a twin-screw extruder at a temperature of 130°C to 160°C to obtain functional material masterbatch; the functional material masterbatch is prepared into a functional material layer with a thickness of 0.2 mm to 0.5 mm by melt extrusion molding process; finally, the functional material layer is sandwiched between the first encapsulation layer and the second encapsulation layer, and a pressure regulating unit is formed by hot pressing. S3. Assemble the elastic composite layer: Arrange the pressure regulating units on the surface of the base elastic layer according to a predetermined spacing and distribution density, and pre-fix the pressure regulating units to the base elastic layer by hot pressing or ultrasonic welding. A microporous breathable layer is placed over the pressure regulating unit to form a dynamic pressure regulating layer; S4, Composite Nonwoven Fabric Layer: The inner and outer nonwoven fabrics are respectively bonded to the two sides of the elastic composite layer, and the waist structure is formed by hot pressing. A hot pressing roller with a textured surface is used to form dotted or grid-like hot pressing bonding areas on the surface of the waist structure. S5. Cutting and shaping: Cut the composite waist structure to the predetermined size and heat-set it at 80℃ to 100℃ for 10 to 30 seconds.

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