Elastic composite material, pants product, and preparation method therefor

Abstract

Provided in the present invention are an elastic composite material, a preparation method therefor, and a pants product. The elastic composite material comprises: a first non-woven fabric, a second non-woven fabric, and adhesive elastic yarns arranged between the first non-woven fabric and the second non-woven fabric. The adhesive elastic yarns use SEBS copolymer as a main component, and not only impart adhesiveness and elasticity to the composite material, but also are arranged in such a manner that a manufactured pants product has gradient elastic zones matching a waist curve of a human body. The present invention combines the hot‑melt adhesiveness and elasticity of SEBS and, by means of an online melt‑bonding integrated process, directly combines inner and outer non-woven fabrics of a waist component, so as to simultaneously achieve structural bonding, high stretchability, and dynamic fitability. The present invention abandons conventional methods in which waist elastic bands and glue bonding are used, can perform combination just by non-woven fabrics and SEBS materials and, while simplifying processes and reducing costs, incorporates an ergonomic waist zonal design, ultimately achieving significant improvements in aspects of cost control, breathability and comfort, softness and skin friendliness, and overall wearing experience.

Description

An elastic composite material and trousers product and their manufacturing method Technical Field

[0001] This invention belongs to the field of absorbent hygiene product manufacturing, specifically relating to an elastic composite material and trouser products and their manufacturing methods. Background Technology

[0002] In the field of disposable hygiene products, especially adult incontinence pants, women's menstrual pants, and baby pull-up diapers, the design of the elastic waistband directly determines the core performance of the product. An ideal waistband structure must simultaneously meet multiple requirements: it must provide a dynamic fit during body movement while avoiding skin marks caused by excessive localized pressure; it must maintain sufficient breathability to prevent stuffiness and discomfort while also being compatible with high-speed production lines for mass production. As consumers' demands for comfort and functionality continue to rise, the technological limitations of traditional elastic waistband materials are becoming increasingly apparent.

[0003] Current mainstream solutions in the industry primarily rely on composite technology using elastic bands or spandex fibers. This technology fixes the elastomer (natural rubber elastic bands or polyurethane-based spandex fibers) to a nonwoven fabric substrate through hot melt adhesive lamination or ultrasonic welding. While providing basic elasticity, it has significant drawbacks: the mechanical properties of the elastomer are limited by the raw material supplier, and tension and resilience are difficult to control freely; using fine denier elastic bands to improve comfort requires increasing the number of bands, leading to increased costs; the use of adhesives not only hardens the product's feel but also increases raw material costs, complicates the process, and introduces potential chemical safety risks; of particular concern is the controversial biotoxicity of MDI (diphenylmethane diisocyanate) in spandex fiber raw materials, which may pose health risks with long-term exposure. Furthermore, the solvent DMAc (dimethylacetamide) commonly used in solution dry spinning processes for producing spandex fibers has residue issues. This substance is toxic and may damage the respiratory system and liver, and solvent residue is an inherent defect that is difficult to completely avoid with this technical approach.

[0004] To overcome the shortcomings of adhesives, elastic membrane composite technology emerged. This technology directly laminates elastic films such as TPU (thermoplastic polyurethane) with non-woven fabrics, eliminating the need for elastic band fastening. However, its inherent defects limit its application effectiveness: the initial modulus of the elastic membrane is generally too high, resulting in excessive constriction at the waist, necessitating a complex perforation process to weaken its elasticity; more importantly, the continuous membrane structure severely hinders airflow, and even after perforation, its breathability remains far lower than that of a fiber mesh structure, easily causing stuffiness and heat when worn. Simultaneously, the membrane material is prone to permanent deformation after repeated stretching, affecting product lifespan. Furthermore, this elastic membrane material is relatively expensive, hindering cost control.

[0005] Integrated design of elastic nonwoven fabrics is considered a more forward-looking direction, the core of which lies in directly forming a web using fibers with inherent elasticity. However, existing technologies have significant limitations: most elastic nonwoven fabrics rely on finishing processes to impart elasticity, resulting in insufficient recovery rate and durability; the few solutions that incorporate elastic fibers (such as Lycra) face new problems such as high fiber costs and difficulties in color matching. Bright hues of Lycra fibers other than white (such as blue and pink) easily form colored spots on the product surface, and any broken fibers ruin the overall aesthetics; its uneven tension also leads to decreased waistline flatness, affecting folding and packaging efficiency.

[0006] In recent years, adhesive-free bonding technologies (such as WO9734506A1 and CN110290771A) have made progress in reducing costs and improving environmental friendliness by fixing elastomers through mechanical compression. However, this technology has not yet overcome fundamental limitations: its elasticity still relies on traditional rubber bands, failing to address essential issues such as limited raw material performance and strong skin pressure; the complex embossing process places stringent requirements on the strength of the substrate, limiting the range of material choices. Furthermore, the mechanical compression method significantly increases the overall hardness of the material, resulting in a poor feel.

[0007] Styrene thermoplastic elastomers (SBCs, also known as "styrene block copolymers" or "SBC-based resins") have seen rapid development in recent years, with their applications in footwear and adhesives demonstrating excellent elasticity and processability. However, the composite technology of SBCs with nonwoven fabrics still faces challenges: traditional meltblown processes struggle to form continuous elastic monofilaments, while solution spinning encounters issues such as solvent residue. More importantly, the inherent self-adhesive properties of SBCs have not been effectively utilized in existing technologies to replace traditional adhesives. For example, CN110290771A still relies on additional glue for composite bonding, failing to fully realize its dual potential as an elastomer and adhesive in one.

[0008] Specifically, the applicant's prior patent CN1604844A discloses an elastic strand adhesive laminate product, which achieves elastic lamination of the surface fabric through thermoplastic adhesive elastic fibers. However, this solution has the following technical limitations: It lacks in-depth research into the precise composition and molecular structure of SBC-based resin and its impact on product performance; it lacks detailed quantitative description and optimization of the impact of specific process parameters (such as spinning temperature, pressure, speed, spinneret aperture, and draw ratio) on the performance of elastic fibers and the composite effect; it lacks specific and quantitative descriptions of the performance indicators of elastic composite fabrics in absorbent articles, such as the permanent deformation rate and tensile strength retention rate of cyclic tensile properties, air permeability, and "uniform wrinkling characteristics"; it does not address the differentiated elastic zoning design of the waistband, nor does it mention its online assembly scheme with the main body of the article.

[0009] Although SBC materials have received much attention in recent years (for example, CN117429144A discloses a styrene copolymer-based resin for preparing elastic fabrics), how to successfully apply its advantages to diaper waistbands and systematically solve core challenges such as balancing self-adhesion and elasticity, efficient online lamination, cost control, and the overall performance of the final product are still key issues that urgently need to be addressed in this field. Summary of the Invention

[0010] The purpose of this invention is to provide a highly comfortable elastic waistband structure for absorbent articles and its online manufacturing method, aiming to solve the shortcomings of existing diaper waistbands in terms of elasticity, softness, breathability, production efficiency and cost.

[0011] Terminology Definition

[0012] In this invention, the term "non-uniform arrangement" refers to a structural design in which different regions of an elastic composite material exhibit differentiated elastic properties by adjusting at least one of the elastic filament spacing, elastic filament diameter, and / or the stretch ratio applied to the elastic filament, thereby forming a gradient elastic partition in the waist area of ​​the product that matches the curve of the human waist and hips.

[0013] In this invention, the term "nonwoven fabric" or "non-woven textile" refers to a web having a structure of individual fibers or yarns, but not necessarily in a manner identifiable as a knitted fabric. Suitable examples of nonwoven fabrics or non-woven textiles include, but are not limited to: meltblown webs, spunbond webs, bonded-carded webs, air-blown webs, co-formed webs, and hydroentangled webs.

[0014] In this invention, the terms "elastomer" or "elastic" refer to a material that, by applying a tensile force, is stretched in at least one direction (e.g., the MD direction), and by releasing the tensile force, shrinks / recovers to approximately its original size. For example, a stretched material may have an extended length at least about 50% longer than its relaxed, unstretched length, and by releasing the tensile force, it may recover to a length within at least 50% of its extended length. A hypothetical example could be a 1-inch long material sample that can be stretched to at least 1.5 inches and, by releasing the tensile force, will recover to a length of no more than 1.25 inches. Ideally, the material shrinks or recovers at least 50%, more ideally, at least 80% of the extended length.

[0015] As used herein, the term "elastic filament" includes, for example, but not limited to, elongated materials that are elastic, such as, but not limited to, elastic rubber. Elastic rubber can, for example, be made from spandex using a spinning process on a warp beam.

[0016] To achieve the aforementioned objective, the present invention employs the following technical solution:

[0017] A first aspect of the present invention provides an elastic composite material, the elastic composite material comprising:

[0018] First nonwoven fabric;

[0019] The second nonwoven fabric, and

[0020] Multiple adhesive elastic filaments are disposed between the first nonwoven fabric and the second nonwoven fabric, wherein the adhesive elastic filaments are SEBS copolymers or contain SEBS copolymers.

[0021] The first nonwoven fabric and the second nonwoven fabric are bonded together by the multiple adhesive elastic filaments, which impart elasticity to the elastic composite material. Furthermore, the multiple adhesive elastic filaments are arranged non-uniformly in the elastic composite material, thereby creating a gradient elastic zone in the waist area of ​​the trousers made of the elastic composite material that matches the curve of the human waist and hips.

[0022] In a preferred embodiment of the present invention, based on the total longitudinal length of the trousers, the gradient elastic partition is configured as follows:

[0023] The front waistband of the trousers is divided into four elastic zones from top to bottom: the first zone accounts for 5%-8% of the length and has an elongation ratio of 270%-310%; the second zone accounts for 10%-20% of the length and has an elongation ratio of 220%-270%; the third zone accounts for 5%-15% of the length and has an elongation ratio of 180%-250%; and the fourth zone is an inelastic zone or a low-elastic zone with an elasticity lower than that of the third zone.

[0024] The back waist portion of the trousers is divided into four elastic zones from top to bottom: the first zone accounts for 5%-8% of the length and has an elongation ratio of 270%-310%; the second zone accounts for 10%-20% of the length and has an elongation ratio of 220%-270%; the third zone accounts for 15%-35% of the length and has an elongation ratio of 180%-250%; and the fourth zone is an inelastic zone or a low-elastic zone with an elasticity lower than that of the third zone.

[0025] In various embodiments of the present invention, the fourth region of the front waistband overlaps with or is connected to the fourth region of the back waistband, together forming the crotch area of ​​the trousers.

[0026] The total longitudinal length of the trousers refers to the total length from the top edge of the front waistband to the bottom edge of the back waistband when the product is laid flat, i.e., the total vertical length of the flat product shown in the product schematic diagrams in Figures 4 and 7. Figure 3 is a schematic diagram of the elastic partitioning of the waistband assembly of the trousers provided by the present invention. According to the present invention, as shown in Figures 3 and 4, the "length ratio" can also be referred to as the "width ratio".

[0027] Preferably, the density of the SEBS copolymer is 0.88-0.96 g / cm³. 3 Its weight-average molecular weight is preferably 100,000-200,000, more preferably 130,000-150,000. The molecular weight range described in this invention effectively balances the processing fluidity of the material with its mechanical strength after molding.

[0028] Preferably, the styrene monomer content in the SEBS copolymer is 13-58 wt%, more preferably 18-31 wt%. The melt flow rate of the SEBS copolymer, measured at 230°C and a load of 2.16 kg, is preferably 1-18 g / 10 min, more preferably 7-18 g / 10 min.

[0029] This invention, through extensive experimentation, has discovered that using SEBS copolymers within a specific molecular weight range and precisely blending them can significantly optimize the overall performance of the final product. Specifically, in a preferred embodiment, the SEBS copolymer comprises a mixture of SEBS with a weight average molecular weight of 140,000-145,000 (represented by G1645, offering higher strength and hardness) and SEBS with a weight average molecular weight of 130,000-135,000 (represented by G1657, offering excellent elasticity) in a weight ratio of 3.5:1 to 5.5:1.

[0030] Surprisingly, even when this specific ratio of SEBS blend is applied to trousers without gradient elasticity zones, it still produces unexpected technical effects, significantly improving their overall elasticity and fit comfort.

[0031] Therefore, in another aspect of the present invention, an elastic composite material is also provided, the elastic composite material comprising: a first nonwoven fabric, a second nonwoven fabric, and a plurality of adhesive elastic filaments disposed between the first nonwoven fabric and the second nonwoven fabric, wherein the adhesive elastic filaments are SEBS copolymers or contain SEBS copolymers, wherein the first nonwoven fabric and the second nonwoven fabric are bonded by the plurality of adhesive elastic filaments to form the elastic composite material, and the adhesive elastic filaments impart elasticity to the elastic composite material; preferably, the SEBS copolymer comprises a mixture of SEBS with a weight average molecular weight of 140,000-145,000 and SEBS with a weight average molecular weight of 130,000-135,000 in a weight ratio of 3.5:1 to 5.5:1, and wherein the plurality of adhesive elastic filaments are uniformly or non-uniformly arranged in the elastic composite material. In another aspect of the invention, a trouser product is also provided, having a front area, a back area, and a crotch area, and comprising: an absorbent assembly extending longitudinally between the front and back areas, and including an inner layer facing the wearer, an outer layer facing away from the wearer, and an absorbent structure disposed between the inner and outer layers; and a waistband assembly attached to the absorbent assembly and defining a waist opening of the absorbent article, wherein the waistband assembly is formed of the aforementioned elastic composite material.

[0032] The specific proportions of SEBS blended mentioned above are not simply a matter of performance additives, but rather produce a significant synergistic enhancement effect. For example, mechanical properties are optimally balanced, processing performance and morphological stability are significantly improved, lightweight design feasibility is enhanced, and overall performance advantages are evident. The preferred embodiment of this invention, through a strategy of blending high and low molecular weight SEBS at specific molecular weights and weight ratios of 3.5:1 to 5.5:1, successfully prepared adhesive elastic yarns that achieved an unprecedented balance between mechanical strength, elongation, lamination softness, and resilience, thus providing trouser products with an elastic waistband composite material that combines excellent comfort and long-term morphological stability.

[0033] Preferably, the SEBS copolymer satisfies one or more of the following conditions: Shore A hardness: 20-60 HA; glass transition temperature: <-30℃; melting point or softening point: 80-150℃, preferably 90-130℃; molecular weight distribution (Mw / Mn): 1.5-3.0, preferably 1.8-2.5; 190℃, 100s -1 Melt viscosity at shear rate: 500-5000 Pa·s, preferably 1000-3000 Pa·s.

[0034] According to the present invention, the elastic composite material has the property of uniform wrinkling after stretching.

[0035] Preferably, the relaxation basis weight of the adhesive elastic filament is 25-80 g / m. 2 Preferably 25-70g / m 2 Its basis weight at 150% stretch is 20-50 g / m³. 2 Preferably 25-45g / m 2 The width of the adhesive elastic filament is preferably 5-50 μm, more preferably 10-30 μm. The spacing between the plurality of adhesive elastic filaments is preferably 1-8 mm, more preferably 1.5-4 mm.

[0036] Preferably, the relaxation air permeability of the elastic composite material is 400-900 ft. 3 / ft 2 / min, preferably 550-750ft 3 / ft 2 / min; air permeability at 150% stretch is 500-1000 ft. 3 / ft 2 / min, preferably 650-850ft 3 / ft 2 / min.

[0037] Preferably, the basis weight of the first nonwoven fabric and the second nonwoven fabric is independently 5-25 g / m³. 2 Preferably 5-15g / m 2 Preferably, the first nonwoven fabric and the second nonwoven fabric are each independently spunbond nonwoven fabric, bicomponent nonwoven fabric, or hot-air nonwoven fabric.

[0038] In some preferred embodiments of the present invention, the first nonwoven fabric and / or the second nonwoven fabric may be selected from elastic nonwoven fabric.

[0039] A second aspect of the present invention provides a method for preparing the above-mentioned elastic composite material, comprising:

[0040] The adhesive elastic material containing SEBS copolymer is heated to 130-190°C to melt;

[0041] A spinneret is used to produce adhesive elastic filaments from molten adhesive elastic material.

[0042] In a stretched state, multiple adhesive elastic filaments are placed between a first nonwoven fabric and a second nonwoven fabric in a non-uniform arrangement, and the first nonwoven fabric and the second nonwoven fabric are bonded together by thermal bonding, pressure bonding, self-adhesion of the materials themselves and / or ultrasonic bonding to obtain the elastic composite material.

[0043] The non-uniform arrangement is achieved by adjusting at least one of the elastic filament spacing, elastic filament diameter, and / or draw ratio. Optionally, the method further includes stretching the elastic composite material along the machine direction to adjust its tension.

[0044] According to the method provided in the second aspect of the present invention, the process parameters for making the adhesive elastic material into adhesive elastic filaments may include: spinning temperature 200-230°C, spinning pressure 5-15 MPa, spinning speed 500-1500 m / min, and spinneret orifice diameter 0.2-0.45 mm.

[0045] In a third aspect, the present invention provides a trouser product having a front area, a back area, and a crotch area, and including an absorbent component and a waistband component, the absorbent component covering the crotch area and extending to the front and back areas; the waistband component being disposed in the front and back areas and connected to the absorbent component to form a waist opening, wherein the waistband component is formed of the elastic composite material described in the first aspect of the present invention.

[0046] According to the trousers product provided by the present invention, the trousers product is any one of baby diapers, baby pull-up trousers, adult incontinence trousers, or menstrual trousers.

[0047] A fourth aspect of the present invention provides an online manufacturing method for the above-mentioned trousers products, comprising:

[0048] S1. Spinning: The SEBS copolymer is melted and passed through a spinning die to form a continuous adhesive elastic filament bundle;

[0049] S2. Online composite: At room temperature, the adhesive elastic filaments are directly sprayed or laid on the surface of a continuously running first nonwoven fabric. Utilizing the self-adhesive properties of the SEBS copolymer, a second nonwoven fabric is laid on the surface of the adhesive elastic filaments and laminated without the need for additional adhesives to form an elastic composite material.

[0050] S3. Online assembly: The elastic composite material formed in step S2 is directly transported to the absorbent component production station and assembled online with the absorbent component to form the trousers product.

[0051] Optionally, step S2 may further include laminating the formed elastic composite material with a third nonwoven fabric, or step S3 may further include laminating a third nonwoven fabric onto the surface of the formed trousers product.

[0052] Preferably, the basis weight of the third nonwoven fabric is 5-25 g / m³. 2 Preferably 5-15g / m 2The third nonwoven fabric can be spunbond nonwoven fabric, bicomponent nonwoven fabric, or hot-air nonwoven fabric. In some preferred embodiments of the present invention, the third nonwoven fabric can be an elastic nonwoven fabric.

[0053] According to the method provided in the fourth aspect of the present invention, the spinning process parameters in step S1 may include: spinning temperature 200-230℃, spinning pressure 5-15MPa, spinning speed 500-1500m / min, and spinneret orifice diameter 0.2-0.45mm.

[0054] Preferably, the running speed of the first nonwoven fabric in step S2 is 100-300m / min.

[0055] According to the online manufacturing method provided by this invention, elastic filaments formed by SEBS spinning are online composited with two layers of nonwoven fabric and assembled online with the absorbent substrate, achieving continuous online production without rewinding, significantly improving production efficiency and reducing costs. The elastic filaments are self-adhesive, thus requiring no additional adhesives to firmly bond with the nonwoven fabric. In addition to the conventional uniform distribution, this invention implements differentiated elastic zone design according to needs, that is, the front and back waistbands are divided into different elastic areas along the product's length with specific stretch ratios, further enhancing the wearing experience. This invention is particularly suitable for absorbent items such as diapers and adult incontinence products, possessing excellent elasticity, softness against the skin, high breathability, and good cyclic stretching performance, providing superior wearing comfort and leak-proof performance.

[0056] The beneficial effects of this invention are as follows:

[0057] 1. By using SEBS copolymer as the adhesive elastic filament, the functions of adhesive and elastomer are combined into one, simplifying the material structure and significantly reducing costs.

[0058] 2. The gradient elastic zones formed by the non-uniform arrangement of the adhesive elastic yarns can accurately match the curves of the waist and hips of the human body, effectively improving the dynamic fit and wearing comfort of the product, and avoiding excessive local pressure.

[0059] 3. Based on the open structure of the fiber mesh, the composite material has excellent air permeability in both relaxed and stretched states, which is far superior to elastic membrane materials.

[0060] 4. Utilizing the self-adhesive properties of SEBS material itself enables online glue-free lamination, simplifying the process, increasing production efficiency, and avoiding problems such as hardening and chemical risks associated with traditional adhesives.

[0061] 5. The online manufacturing method described above realizes an integrated assembly line operation from elastic material molding to trouser product assembly, which greatly improves production efficiency and economic benefits.

[0062] Brief description of the attached figures

[0063] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings, wherein:

[0064] Figure 1 is a photograph of the elastic composite material prepared in Example 1;

[0065] Figure 2 is a photograph of the trousers product obtained in Example 9;

[0066] Figure 3 is a schematic diagram of the elastic partitioning of the waistband component of the trousers product provided by the present invention;

[0067] Figure 4 is a schematic diagram of the distribution of the elastic partitions of the waistband component of the trousers product provided by the present invention in the trousers product.

[0068] Figure 5 is a magnified photograph of a single elastic filament obtained in Example 10 under an electron microscope;

[0069] Figure 6 is a magnified photograph of the composite elastic yarn and nonwoven fabric prepared in Example 10 under an electron microscope.

[0070] Figure 7 is a schematic diagram of the arrangement of adhesive elastic filaments in each elastic zone of the elastic composite material prepared in Example 10.

[0071] Figure 8 is a schematic diagram of the arrangement of the adhesive elastic filaments in the section PP' (dashed line) in Figure 7;

[0072] Figure 9 is a graph showing the elastic tensile test curves of trouser products with different elastic zones obtained in Example 10.

[0073] Figure 10 is a comparison of the elastic tensile test curves of the undivided trousers product obtained in Example 9 and the trousers product with different elastic divisions obtained in Example 10.

[0074] Figure 11 is a schematic diagram comparing the waist tension of the trousers product obtained in Example 9 of the present invention with that of conventional elastic materials.

[0075] The best way to implement an invention

[0076] The present invention will be further described below with reference to the embodiments. The embodiments are merely illustrative and are in no way intended to limit the scope of the present invention.

[0077] The materials used in the examples and comparative examples are described below:

[0078] The SEBS copolymers used in the examples and comparative examples were purchased from Esbon New Materials (Shanghai) Co., Ltd., including G1645 (molecular weight 142,000) and G1657 (molecular weight 133,000), with a styrene monomer content of 13-58 wt%. The melt flow rate (MFR) of the SEBS copolymers, measured at 230°C and a load of 2.16 kg, was 3-6 g / 10 min. The nonwoven fabric used in the examples was spunbond nonwoven fabric purchased from Berry Nonwovens (China) Co., Ltd.

[0079] The test methods used in the examples and comparative examples are described below:

[0080] 1. Tensile strength and elongation test

[0081] The test was conducted using an MTS Criterion™ Model 43 testing machine, in accordance with the KCC STM 5667 standard. The specimen size was 25.4±3 mm × 165.1±3 mm, the clamp spacing was set to 101.6±1 mm, and the tensile speed was 305±10 mm / min. The testing system automatically recorded the peak load (accuracy 0.01 gf) and elongation at break (accuracy 0.1%) of the specimen.

[0082] 2. Peel strength test

[0083] The same testing machine as Test 1 described above was used, and the test was conducted according to the KCC STM 5668 standard. The sample size was 50.8±3 mm square, the clamp spacing was set to 50.8±1 mm, and the peeling speed was 305±10 mm / min. During the test, the clamps automatically returned after displacement reached 150 mm, and the system recorded and output the average peel strength value.

[0084] 3. Tension relaxation rate test

[0085] A 50mm × 120mm specimen was fixed on a flat plate, and the initial length L1 (100mm) was marked. The specimen was stretched to 250mm from the marked point (150% elongation) and fixed, and placed in an oven at 40℃ for 4 hours. After removal, the fixation was released, and the length L2 after shrinkage was measured. The length failure rate was calculated using the formula: (L2-L1) / L1×100%.

[0086] 4. Tensile length test

[0087] Take a sample with a width > 150 mm and a length > 200 mm, fix one side with a tensioner and record the initial length. Stretch the unfixed side uniformly along the vertical direction, record the length after stretching, and calculate the difference between the stretched length and the original length as the actual stretch length.

[0088] Actual stretched length (mm) = Length after stretching (mm) - Original length (mm)

[0089] 5. Air permeability test

[0090] The Textest FX 3300LabAir breathability tester (test area 32cm²) was used. 2 (Pressure 125 Pa). Clamp a 12×12 inch sample onto the test head, start the device, and after the displayed value stabilizes, directly read the air permeability value.

[0091] 6. Raw material basis weight test

[0092] Take an area of ​​not less than 130cm 2 After weighing the sample with a balance, the mass per unit area is calculated according to the formula: basis weight = weight / area.

[0093] Example 1

[0094] An adhesive elastic material with a density of 0.96 g / cm³ was prepared by mixing SEBS copolymers of grades G1645 and G1657 at a ratio of 4.5:1 using a twin-screw extruder with heating. 3 .

[0095] The prepared adhesive elastic material is heated to 180°C to melt, and the melted adhesive elastic material is passed through a spinneret to form adhesive elastic filaments; after cooling, it is stretched; the adhesive elastic filaments are allowed to cool and gradually solidify to form adhesive elastic filaments with a weight of 0.083 g / filament / m and a diameter of about 25 μm. The elastic filaments are stretched in the machine direction to obtain the tension required for the product.

[0096] Under tension, multiple adhesive elastic filaments are bonded together at equal intervals of 2.7 mm between the first and second nonwoven fabrics in the machine direction. After compaction and relaxation, the basis weight of the resulting multiple adhesive elastic filaments is 27.64 gsm, thus obtaining the elastic composite material of the present invention with a basis weight of approximately 32 gsm. A photograph of the elastic composite material obtained in this embodiment is shown in Figure 1.

[0097] Example 2

[0098] A lightweight variant was prepared by mixing SEBS copolymers of types G1645 and G1657 in a 4.5:1 ratio using a twin-screw extruder for heating and mixing.

[0099] The prepared adhesive elastic material is heated to 160°C to melt, and the melted adhesive elastic material is passed through a spinneret to form adhesive elastic filaments; after cooling, it is stretched; the adhesive elastic filaments are allowed to cool and gradually solidify to form adhesive elastic filaments with a weight of 0.07 g / filament / m and a diameter of about 15 μm. The elastic filaments are stretched in the machine direction to obtain the tension required for the appropriate product.

[0100] In the stretched state of the adhesive elastic filaments, multiple adhesive elastic filaments are uniformly and equally spaced together between the first and second nonwoven fabrics in the machine direction, compacted and then relaxed, so that the basis weight of the multiple adhesive elastic filaments formed is 25 gsm, and the elastic composite material of the present invention is obtained with a basis weight of about 30 gsm.

[0101] Example 3

[0102] An adhesive elastic material was prepared by mixing SEBS copolymers of type G1645 and G1657 in a ratio of 5.5:1 using a twin-screw extruder for heating.

[0103] The prepared adhesive elastic material is heated to 170°C to melt, and the melted adhesive elastic material is passed through a spinneret to form adhesive elastic filaments; after cooling, it is stretched; the adhesive elastic filaments are allowed to cool and gradually solidify to form adhesive elastic filaments with a weight of 0.09 g / filament / m and a diameter of about 30 μm. The elastic filaments are stretched in the machine direction to obtain the tension required for the appropriate product.

[0104] In the stretched state of the adhesive elastic filaments, multiple adhesive elastic filaments are uniformly and equally spaced together between the first and second nonwoven fabrics in the machine direction, compacted and then relaxed, so that the basis weight of the multiple adhesive elastic filaments formed is 30 gsm, and the elastic composite material of the present invention is obtained with a basis weight of about 40 gsm.

[0105] Example 4

[0106] The elastic composite material was prepared using a method essentially the same as in Example 1, except that: SEBS copolymers of types G1645 and G1657 were mixed in a ratio of 3.5:1 using a twin-screw extruder to heat and mix them to obtain an adhesive elastic material; the adhesive elastic material was heated to 175°C to melt, and the spinning process was controlled to ensure that the resulting adhesive elastic filaments were 0.09 g / filament / m with a diameter of approximately 30 μm; in the composite process, the arrangement of multiple adhesive elastic filaments was controlled so that the total basis weight of the adhesive elastic filaments in the resulting elastic composite material was 30 gsm, and the final basis weight of the composite material was approximately 40 gsm.

[0107] Example 5

[0108] This example aims to illustrate that although high strength can be obtained when using high molecular weight SEBS (G1645) alone, the elongation of the material is not as good as the compound schemes in Examples 1-4.

[0109] The elastic composite material was prepared in essentially the same manner as in Example 1, except that: SEBS copolymer of type G1645 was used alone as the adhesive elastic material, without adding G1657; the spinning process was controlled so that the resulting adhesive elastic filaments were 0.09 g / filament / m with a diameter of about 30 μm, and the total basis weight of the adhesive elastic filaments in the final composite material was 30 gsm.

[0110] Example 6

[0111] This example aims to illustrate that when low molecular weight SEBS (G1657) is used alone, although the material has good elasticity, its tensile strength is lower than that of the compound schemes in Examples 1-4.

[0112] The elastic composite material was prepared in essentially the same manner as in Example 1, except that: SEBS copolymer of type G1657 was used alone as the adhesive elastic material, without adding G1645; the spinning process was controlled so that the resulting adhesive elastic filaments were 0.09 g / filament / m with a diameter of about 30 μm, and the total basis weight of the adhesive elastic filaments in the final composite material was 30 gsm.

[0113] Example 7

[0114] This embodiment aims to illustrate that when the proportion of low molecular weight SEBS (G1657) is too high and exceeds the preferred range, the tensile strength of the material is improved but still not as good as the compounding schemes in Examples 1-4.

[0115] The elastic composite material was prepared in a manner essentially the same as in Example 1, except that: SEBS copolymers of type G1645 and G1657 were mixed in a 2:1 ratio by heating with a twin-screw extruder to obtain an adhesive elastic material; the spinning process was controlled so that the resulting adhesive elastic filaments were 0.09 g / filament / m with a diameter of approximately 30 μm, and the total basis weight of the adhesive elastic filaments in the final composite material was 30 gsm.

[0116] Example 8

[0117] This embodiment aims to illustrate that when the proportion of high molecular weight SEBS (G1645) is too high and exceeds the preferred range, the elongation of the material is improved but still not as good as the compounding schemes in Examples 1-4.

[0118] The elastic composite material was prepared in a manner essentially the same as in Example 1, except that: SEBS copolymers of type G1645 and G1657 were mixed in a 7:1 ratio by heating with a twin-screw extruder to obtain an adhesive elastic material; the spinning process was controlled so that the resulting adhesive elastic filaments were 0.09 g / filament / m with a diameter of approximately 30 μm, and the total basis weight of the adhesive elastic filaments in the final composite material was 30 gsm.

[0119] Comparative Example 1

[0120] This comparative example aims to illustrate the inherent drawbacks in terms of elongation, breathability, and cost when SEBS materials of the same composition are made into breathable membranes instead of elastic filament structures.

[0121] SEBS blends were prepared using essentially the same raw materials and mixing ratios as in Example 1 (G1645 and G1657 were mixed at a ratio of 4.5:1), except that a casting process was used to form a fish-scale-shaped breathable membrane with a basis weight of 30 gsm from the melt blends, rather than spinning to form an elastic mesh structure.

[0122] The performance test results of Examples 1-8 and Comparative Example 1 are shown in Table 1.

[0123] Table 1

[0124] Comparing the elastic filament composite material of Example 1 with the fish-scale breathable elastic membrane of Comparative Example 1, the advantages of the elastic filament of the present invention are mainly reflected in the following three aspects:

[0125] 1. Lightweight and cost advantages: While achieving similar elasticity and strength properties, the elastic filament composite material of this invention has a lower basis weight (27.64 gsm compared to 30 gsm). This lightweight characteristic directly leads to a reduction in raw material consumption, thus possessing better potential for cost control.

[0126] 2. Superior air permeability: Even though the elastic membrane in Comparative Example 1 uses a fish-scale air-permeable structure, its air permeability is still far inferior to the single-filament arrangement of the elastic filament structure in this invention. Specific test data shows that the air permeability of the elastic filament composite material of this invention is approximately 1.5 times that of the fish-scale elastic membrane, demonstrating a significant advantage in air permeability.

[0127] 3. Simplified Process and Higher Production Efficiency: From a production process perspective, this invention achieves a simpler and smoother process by using online spinning and leveraging the self-adhesive properties of materials to achieve adhesive-free lamination. This not only reduces production steps (such as eliminating the need for additional unwinding and gluing processes), but also lowers energy consumption and raw material (adhesive) costs, thereby improving overall production efficiency and optimizing production costs.

[0128] Furthermore, comparing the elastic composite materials of Examples 1-8 with the elastic composite material of Comparative Example 1, the advantages of the preferred embodiment of the present invention are mainly reflected in the following three aspects:

[0129] 1. Mechanical properties achieve optimal balance

[0130] Compared to Examples 1-4, Example 5 (single G1645) exhibits high tensile strength but low elongation; Example 6 (single G1657) has low tensile strength. The preferred embodiment of this invention, by blending the two in a preferred ratio, stabilizes the tensile strength within the 4000-5800 gf range that meets the usage standards, while maintaining a suitable elongation of 65%-70%, achieving an ideal combination of high strength and high elasticity.

[0131] Although Example 7 (with an excessively high proportion of G1657) showed improvement over Example 6, its tensile strength still failed to reach the level of Examples 1-4; although the elongation of Example 8 (with an excessively high proportion of G1645) was improved compared to Example 5, it still did not reach the level of Examples 1-4. This demonstrates that the preferred compounding ratio of 3.5:1 to 5.5:1 of the present invention achieved unexpected technical effects.

[0132] 2. Significantly improved processing performance and morphological stability

[0133] In Examples 1-4 of this invention, under the preferred compounding ratio, the stretch relaxation ratio (characterizing permanent deformation) of the materials remained at an extremely low level after being stretched by 150% and 200% (Example 1: 125%, 124%). This indicator is far superior to the fish scale film of Comparative Example 1 (138%), proving that the compounding system has excellent deformation recovery ability and can ensure that the product is not easily relaxed after repeated use and maintains a long-lasting fit.

[0134] Example 2, despite achieving a lightweight design (25gsm), still exhibits excellent core performance, demonstrating the potential of this compound system in reducing costs and improving comfort.

[0135] 3. Significant overall performance advantages

[0136] Comparative Example 1, which uses the same material to make a fish-scale membrane, not only suffers from excessively low elongation but also exhibits inherent defects such as poor air permeability and high cost. In contrast, this invention employs an elastic filament structure and optimizes the compounding ratio, ensuring that mechanical properties meet standards while also achieving excellent air permeability and cost-effectiveness.

[0137] The MD peel strength (160-205gf) of all embodiments is within a reasonable range, indicating that the compounded adhesive elastic yarn provides sufficient bonding strength while avoiding material hardening and ensuring the soft touch of the final product.

[0138] Therefore, the preferred embodiment of the present invention successfully prepared an adhesive elastic yarn with excellent comprehensive performance by employing a strategy of compounding G1645 and G1657 with specific molecular weights at a weight ratio of 3.5:1 to 5.5:1. This approach overcomes the shortcomings of comparative examples in terms of substandard performance, ensuring that the final elastic composite material meets the high standards required for disposable hygiene products in terms of mechanical strength, elongation, resilience, and processing performance, providing a key material foundation for achieving comfortable, durable, and economical trouser products.

[0139] Comparison of the elastic composite material of the present invention with conventional elastic materials

[0140] The following tests were conducted on the elastic composite material prepared in Example 1, and a comparative analysis was performed with conventional materials in the industry, Kimberly-Clark elastic film (model: C2011-0951) and ordinary rubber bands. The test results are shown in Tables 2-6.

[0141] The preparation method of the comparative samples is as follows:

[0142] Ordinary rubber band composite material: After Lycra rubber bands are unwound, they are pulled to a predetermined station by a guide wheel system. Special rubber band adhesive is applied by a glue gun. Then, they are bonded to the upper and lower waist hot air nonwoven fabrics in the main machine, and finally formed into an ordinary rubber band composite material that combines hot air nonwoven fabric and Lycra rubber bands with adhesive.

[0143] Kimberly-Clark elastic film composite material: After unwinding, the Kimberly-Clark elastic film is stretched to a predetermined position in the main machine, and rubber band adhesive is sprayed on it with a glue gun. Then, it is stretched to be combined with the upper and lower waist non-woven fabrics to finally form an integral elastic composite material.

[0144] Table 2. Tensile strength and elongation tests

[0145] Table 3. Peel Strength Test

[0146] Table 4. Tensile relaxation rate and tensile length test

[0147] Table 5. Air permeability test

[0148] Table 6. Basis Weight Test of Raw Materials

[0149] The test results in the table above show that:

[0150] Tensile strength and elongation: In the width direction of the material: the tensile strength of this embodiment is slightly lower than that of Kimberly-Clark elastic film and ordinary rubber bands, which is acceptable considering the reduced weight of the wrapped nonwoven fabric; the elongation is slightly greater than that of Kimberly-Clark elastic film and ordinary rubber band composites. In the length direction of the material: the tensile strength of this embodiment is comparable to that of Kimberly-Clark elastic film and ordinary rubber bands, while the elongation is significantly higher than that of Kimberly-Clark elastic film and ordinary rubber band composites.

[0151] Peel strength: The peel strength of the embodiments of the present invention is at the same level as that of ordinary rubber bands, and is significantly better than that of Kimberly-Clark elastic film.

[0152] Stretching relaxation rate: The embodiment of the present invention is at the same level as Kimberly-Clark's elastic membrane.

[0153] Stretching length: The embodiment of this invention is at the same level as Kimberly-Clark's elastic film.

[0154] Air permeability: The air permeability of the embodiments of the present invention is superior to that of Kimberly-Clark's elastic film. It is worth noting that although the air permeability of the embodiments of the present invention is lower than that of ordinary rubber band composite materials (ordinary rubber band composite materials use hot-air nonwoven fabric with better air permeability, while the embodiments of the present invention use spunbond nonwoven fabric) due to the different nonwoven fabric substrates used, this precisely demonstrates the inherent high air permeability potential of the elastic filament composite material of the present invention.

[0155] Raw material basis weight: The overall basis weight of the embodiments of the present invention is comparable to that of ordinary elastic bands, and significantly lower than that of elastic membranes, which helps to improve breathability and optimize costs. Comparative Example 1 is also significantly lower than Kimberly-Clark's conventional elastic membrane.

[0156] Example 9

[0157] Preparation of trouser products

[0158] Based on the elastic composite material obtained in Example 1, trouser products were manufactured according to the following process:

[0159] The elastic composite material obtained in Example 1 was passed through the material unwinding station and then cut into front and back waistband sections at the slitting station. It then entered the main machine and, according to the required positions, was laminated with the front and rear ends of the absorbent core at the lamination station. Finally, it was cut into individual pieces by a cutter. A photograph of the trousers product obtained in this example is shown in Figure 2.

[0160] Example 10

[0161] Online preparation of trouser products

[0162] An adhesive elastic material with a density of 0.96 g / cm³ was prepared by mixing SEBS copolymers of grades G1645 and G1657 at a ratio of 4.5:1 using a twin-screw extruder with heating. 3 .

[0163] The prepared adhesive elastic material is heated to 180°C to melt, and the molten adhesive elastic material is passed through a spinneret to form adhesive elastic filaments. After cooling, the filaments are stretched. The adhesive elastic filaments are allowed to gradually solidify to form adhesive elastic filaments with a strength of 0.083 g / filament / m and a diameter of approximately 25 μm. The elastic filaments are then stretched in the machine direction to obtain the tension required for the product. As shown in Figures 7 and 8, by adjusting the spacing of the adhesive elastic filaments, elastic zones with different tensile properties are formed in the longitudinal direction of the waistband assembly. Based on the total longitudinal length of the trousers product, the specific zones are as follows:

[0164] The front waist circumference A of the trousers is divided into four elastic zones along the longitudinal direction from top to bottom. The length percentage and stretch ratio of each elastic zone are as follows: the first elastic zone 11 has a length percentage of 7% and a stretch ratio of 290%; the second elastic zone 12 has a length percentage of 15% and a stretch ratio of 250%; the third elastic zone 13 has a length percentage of 10% and a stretch ratio of 220%; and the fourth elastic zone 14 is a non-elastic zone.

[0165] The back waistband B of the trousers is divided into four elastic zones along the longitudinal direction from top to bottom. The length percentage and stretch ratio of each elastic zone are as follows: the first back zone 15 has a length percentage of 7% and a stretch ratio of 290%; the second back zone 16 has a length percentage of 15% and a stretch ratio of 250%; the third back zone 17 has a length percentage of 30% and a stretch ratio of 200%; and the fourth zone 14 is a non-elastic zone.

[0166] In the embodiment shown in Figure 7, the front fourth region and the rear fourth region are the same region, collectively referred to as "fourth region 14", and constitute the crotch area. The elastic composite material of this embodiment is composed of a first nonwoven fabric, a second nonwoven fabric, and multiple transversely parallel elastic filaments 18 disposed between the first nonwoven fabric and the second nonwoven fabric.

[0167] Figure 8 shows a schematic diagram of the cross-section of PP' (dashed line) in Figure 7. This figure only shows one layer of nonwoven fabric; the nonwoven fabric covering the other side of the elastic yarns is not shown. The purpose of this figure is to more clearly illustrate the cross-section and spacing of the elastic yarns. The stretch ratio of each section of the trousers product is controlled by adjusting the spacing of the elastic yarns. In this specific embodiment, the spacing of the elastic yarns in the first front region 11 is 1.5 mm. The spacing of the elastic yarns in the second front region 12 is 2.5 mm. The spacing of the elastic yarns in the third front region 13 is 4 mm. The spacing of the elastic yarns in the first rear region 15 is 1.5 mm. The spacing of the elastic yarns in the second rear region 16 is 2.5 mm. The spacing of the elastic yarns in the third rear region 17 is 4 mm.

[0168] In other embodiments, those skilled in the art can also adjust the stretch ratio of each section of the trousers product by adjusting the diameter of the elastic yarn. Alternatively, those skilled in the art can also adjust the stretch ratio of each section of the trousers product by adjusting the diameter of the elastic yarn.

[0169] After passing through the unwinding station, the elastic composite material is slit into front and back waistbands at the slitting station. It then enters the main unit, where it is laminated with the front and rear ends of the absorbent core according to positional requirements at the lamination station. Finally, it is cut into individual products by a cutter. On the diaper production line, the elastic composite material is cut and then heat-pressed or ultrasonically bonded to the front and back waistbands of the diaper to form an integrated elastic waistband.

[0170] Characterization and performance testing of trouser products

[0171] 1. Microscopic observation

[0172] The microstructure of the material prepared in Example 10 was observed using an electron microscope. Figure 5 shows the microstructure of a single elastic filament, revealing its uniform diameter and smooth surface. Figure 6 shows the composite interface between the elastic filament and the nonwoven fabric, demonstrating a good bond between the elastic filament and the nonwoven fabric fibers, and maintaining a uniform composite structure.

[0173] 2. Wrinkling characteristics

[0174] The wrinkling properties of the trousers prepared in Examples 9 and 10 were verified. The samples were stretched laterally to 150% strain and held for 10 seconds before being released. Fine, uniformly distributed wrinkles were observed on the surface, without localized concentrated or irregular wrinkling, as shown in Figure 2. The results indicate that the elastic composite material of the present invention has excellent uniform wrinkling properties, which helps to improve the fit and smoothness of the product.

[0175] 3. Cyclic tensile properties

[0176] Cyclic tensile tests were conducted on the products of Examples 9 and 10 using an MTS Criterion™-Model 43 tester. The sample size was 76mm × 150mm, the clamp spacing was 50mm, and the tensile speed was 305mm / min. The test results showed that in the same tensile cycle, the tension in the first region (front / back) of the product of Example 10 was greater than that in the second region, and the tension in the second region was greater than that in the third region (Figure 9), verifying that the zoned design can meet the differentiated elasticity requirements of different body parts. The comparison results between Examples 9 and 10 are shown in Figure 10. It can be seen that in Example 10, based on the different sizes of the human body's waist circumference, abdominal circumference, and hip circumference, the zoned design allows the trousers to be set with different stretch ratios, achieving a differentiated distribution of elastic tension in each region. The elastic tension is greatest in the first region and decreases sequentially, thus more accurately conforming to the curves of the human body and improving the comfort and functionality of wearing the garment. In contrast, Example 9, which does not have elastic zoning, provides uniform elastic tension throughout the waist area, ensuring basic comfort; while Example 10's zoning design further optimizes this, allowing the product to more precisely adapt to the differentiated needs of different body parts.

[0177] 4. Comparison of comfort with conventional elastic materials

[0178] Taking size L as an example, a tension comparison test was conducted between Example 9 and trousers using conventional elastic bands (11.1mm spacing) and ultra-fine denier elastic bands (2.1mm spacing). The tension change within a waist circumference range of 900-1400mm was measured, and a waist circumference-tension curve was plotted, as shown in Figure 11. The central square area represents the preset ergonomic comfort zone for the human waist. The test results show that the test curve of Example 9 of this invention is within the ergonomic comfort zone, while the comparison sample deviates from this zone. This indicates that the elastic composite material of this invention, while maintaining product durability, better meets ergonomic requirements and provides superior wearing comfort.

[0179] The specific embodiments and accompanying drawings described in this specification are only for more clearly illustrating the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent changes, modifications, and substitutions made by those skilled in the art to the embodiments without departing from the spirit and principles of the present invention should be included within the scope of protection defined by the claims of the present invention. In particular, any implementation method based on the core inventive point of the present invention, namely, using SEBS copolymer as an adhesive elastic filament with both adhesive and elastic functions, and achieving the formation of a gradient elastic zone matching the curve of the human body in the waist area of ​​trouser products through its non-uniform arrangement, regardless of whether it involves the specific molecular weight and compounding ratio of SEBS copolymer, the morphology and arrangement parameters of adhesive elastic filament, the specific division method of gradient elastic zone, or the adjustment and optimization of its online compounding and preparation process, as long as it utilizes the same concept of the present invention, falls within the scope of protection of the present invention.

Claims

1. An elastic composite material, the elastic composite material comprising: First nonwoven fabric; The second non-woven fabric, and Multiple adhesive elastic filaments disposed between the first nonwoven fabric and the second nonwoven fabric, characterized in that the adhesive elastic filaments are SEBS copolymers or contain SEBS copolymers. The first nonwoven fabric and the second nonwoven fabric are bonded together by the plurality of adhesive elastic filaments, which impart elasticity to the elastic composite material. The multiple adhesive elastic filaments are arranged non-uniformly in the elastic composite material, thereby creating a gradient elastic zone in the waist area of ​​the trousers made of the elastic composite material that matches the curve of the human waist and hips.

2. The elastic composite material according to claim 1, wherein, Based on the total longitudinal length of the trousers, the gradient elastic partition is constructed as follows: The front waistband of the trousers is divided into four elastic zones from top to bottom: The first region has a length ratio of 5%-8% and a stretch ratio of 270%-310%. The second region, comprising 10%-20% of the length, has a stretch ratio of 220%-270%. The third region, accounting for 5-15% of the length, has a stretch ratio of 180%-250%. The fourth region is an inelastic region or a low-elastic region with elasticity lower than that of the third region. The back waist area of ​​the trousers is divided into four elastic zones from top to bottom: The first region has a length ratio of 5%-8% and a stretch ratio of 270%-310%. The second region, comprising 10%-20% of the length, has a stretch ratio of 220%-270%. The third region has a length ratio of 15-35% and a stretch ratio of 180%-250%. The fourth region is an inelastic region or a low-elastic region with elasticity lower than that of the third region.

3. The elastic composite material according to claim 1, wherein, The density of the SEBS copolymer is 0.88-0.96 g / cm³. 3 ; Preferably, the weight-average molecular weight of the SEBS copolymer is 100,000-200,000, more preferably 130,000-150,000.

4. The elastic composite material according to claim 3, wherein, The SEBS copolymer comprises a mixture of SEBS with a weight average molecular weight of 140,000-145,000 and SEBS with a weight average molecular weight of 130,000-135,000 in a weight ratio of 3.5-5.5:

1.

5. The elastic composite material according to any one of claims 1 to 4, wherein, The styrene monomer content in the SEBS copolymer is 13-58 wt%, preferably 18-31 wt%. Preferably, the melt flow rate of the SEBS copolymer, measured at 230°C and 2.16 kg load, is 1-18 g / 10 min, more preferably 7-18 g / 10 min.

6. The elastic composite material according to any one of claims 1 to 4, wherein, The relaxed basis weight of the adhesive elastic filament is 25-80 g / m. 2 Preferably 25-70g / m 2 The basis weight at 150% stretch is 20-50 g / m³. 2 Preferably 25-45g / m 2 ; Preferably, the diameter of the adhesive elastic filament is 5-50 μm, more preferably 10-30 μm; Preferably, the spacing between the plurality of adhesive elastic filaments is 1-8 mm, and more preferably 1.5-4 mm.

7. The elastic composite material according to any one of claims 1 to 4, wherein, The relaxation air permeability of the elastic composite material is 400-900 ft. 3 / ft 2 / min, preferably 550-750ft 3 / ft 2 / min; air permeability at 150% stretch is 500-1000 ft. 3 / ft 2 / min, preferably 650-850ft 3 / ft 2 / min; Preferably, the basis weight of the first nonwoven fabric and the second nonwoven fabric is independently 5-25 g / m³. 2 Preferably 5-15g / m 2 ; Preferably, the first nonwoven fabric and the second nonwoven fabric are each independently spunbond nonwoven fabric, bicomponent nonwoven fabric or hot-air nonwoven fabric. More preferably, the first nonwoven fabric and / or the second nonwoven fabric are elastic nonwoven fabrics.

8. The method of producing an elastic composite material according to any one of claims 1 to 7, characterized by, include: The adhesive elastic material containing SEBS copolymer is heated to 130-190°C to melt; A spinneret is used to produce adhesive elastic filaments from molten adhesive elastic material. In a stretched state, multiple adhesive elastic filaments are placed between a first nonwoven fabric and a second nonwoven fabric in a non-uniform arrangement. The first nonwoven fabric and the second nonwoven fabric are bonded together by thermal bonding, pressure bonding, self-adhesion of the materials themselves, and / or ultrasonic bonding to obtain the elastic composite material. The non-uniform arrangement is achieved by adjusting at least one of the elastic filament spacing, elastic filament diameter and / or stretch ratio. Optionally, the preparation method further includes stretching the elastic composite material along the machine direction to adjust its tension.

9. A trouser garment having a front section, a back section, and a crotch section, and comprising the following components: Absorbent components that cover the crotch area and extend to the front and rear areas; and A waistband assembly, disposed in the front and rear areas and connected to the absorbent assembly to form a waist opening, characterized in that The waistband assembly is formed of an elastic composite material according to any one of claims 1 to 7.

10. The on-line manufacturing method of pant products according to claim 9, characterized in that, Includes the following steps: S1. Spinning: The SEBS copolymer is melted and passed through a spinning die to form a continuous adhesive elastic filament bundle; S2. Online composite: At room temperature, the adhesive elastic filaments are directly sprayed or laid on the surface of a continuously running first nonwoven fabric. Utilizing the self-adhesive properties of the SEBS copolymer, a second nonwoven fabric is laid on the surface of the adhesive elastic filaments and laminated without the need for additional adhesives to form an elastic composite material. S3. Online Assembly: The elastic composite material formed in step S2 is directly conveyed to the absorbent component production station for online assembly with the absorbent component to form the trousers product. Optionally, step S2 may further include laminating the formed elastic composite material with a third nonwoven fabric, or step S3 may further include laminating a third nonwoven fabric onto the surface of the formed trousers product.

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