Electromagnetic shielding material and tent

Abstract

The invention relates to an electromagnetic shielding material and a tent. The electromagnetic shielding material comprises an inner core layer and a shielding structure. The tearing strength of the inner core layer ranges from 35 N to 75 N, and the shielding effectiveness of the inner core layer at the frequency band of 14 kHz to 200 kHz ranges from 3 dB to 15 dB. The number of the shielding structures is at least two, the two shielding structures are symmetrically arranged on the two opposite side faces of the inner core layer, each shielding structure comprises a first shielding layer, a conductive adhesive layer and a second shielding layer which are arranged in a stacked mode, and the second shielding layer is arranged close to the inner core layer relative to the conductive adhesive layer. According to the design of the electromagnetic shielding material, the comprehensiveness of electromagnetic shielding is guaranteed through the synergistic effect of the inner core layer and the double-layer shielding structure, the overall mechanical reliability of the material is improved by means of the high tearing strength of the inner core layer and the interlayer bonding design, the material is evenly stressed through the symmetrical structure, and when the electromagnetic shielding material is used for outdoor tools such as tents, the service life of the material is prolonged. The tent is not prone to deformation or damage in the folding and building process, and the shielding performance and the use durability are both considered.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic shielding materials, in particular to an electromagnetic shielding material and a tent. BACKGROUND

[0002] The electromagnetic shielding tent as a kind of movable electromagnetic protection facility has important applications in the fields of military secret communication, electronic testing, medical silence and personal privacy protection. Its technical principle is mainly based on electromagnetic shielding theory, that is, using conductive or magnetic material to form a continuum, and attenuating electromagnetic wave energy through reflection, absorption and multiple reflection mechanism. The current mainstream products are mostly made of flexible shielding materials such as metal fiber blended fabric, chemical silver / copper plated nylon cloth and metal foil composite fabric, aiming to balance portability and shielding effectiveness.

[0003] However, in actual application, most of the existing electromagnetic shielding tents use single-layer thin shielding materials for the purpose of portability, which has limited absorption loss under low frequency, especially power frequency and low frequency magnetic field, and the shielding means is single. In addition, the material itself has insufficient fatigue resistance and mechanical durability at the connection, which can easily lead to degradation of conductive performance due to repeated folding, wear and tear, and the shielding effect will significantly decay over time. These problems jointly restrict the ability of the electromagnetic shielding tent to achieve stable and high-level electromagnetic protection in complex real environments. SUMMARY

[0004] Therefore, it is necessary to provide an electromagnetic shielding material and tent that can ensure shielding effect while improving use reliability.

[0005] The technical scheme is as follows: an electromagnetic shielding material, comprising: an inner core layer, the tear strength of the inner core layer ranges from 35 to 75 N, and the shielding effectiveness of the inner core layer under a frequency band of 14 kHz to 200 kHz ranges from 3 to 15 dB; shielding structures, the shielding structures are at least two, and the two shielding structures are symmetrically arranged on opposite sides of the inner core layer, wherein each shielding structure comprises a first shielding layer, a conductive adhesive layer and a second shielding layer arranged in layers, and the second shielding layer is arranged close to the inner core layer relative to the conductive adhesive layer.

[0006] In one embodiment, the inner core layer has a gram per square meter weight of 210 to 330 g / m 2 .

[0007] In one embodiment, the first shielding layer has a gram per square meter weight of 40 to 240 g / m 2 .

[0008] In one embodiment, the second shielding layer has a gram per square meter weight of 125 to 145 g / m 2 .

[0009] In one of the embodiments, the tearing strength of the laminated structure composed of the first shielding layer and the conductive adhesive layer ranges from 20 to 25 N.

[0010] In one of the embodiments, the second shielding layer comprises a metal layer and an insulating layer, and the metal layer and the insulating layer are at least two layers and are sequentially laminated.

[0011] In one of the embodiments, the shielding effectiveness of the first shielding layer at a frequency of 14 kHz ranges from 5 to 15 dB, and the shielding effectiveness at a frequency of 200 kHz ranges from 10 to 34 dB.

[0012] In one of the embodiments, the shielding effectiveness of the second shielding layer at a frequency of 14 kHz ranges from 13 to 24 dB, and the shielding effectiveness at a frequency of 200 kHz ranges from 32 to 50 dB.

[0013] In one of the embodiments, the inner core layer comprises at least one of a metal blended fabric and a metal composite material.

[0014] In one of the embodiments, the inner core layer comprises a blended glue matrix and a filler mixed in the blended glue matrix, and the filler comprises at least one of a nickel-iron alloy, a permalloy, a nickel-molybdenum magnetic powder, an iron-silicon magnetic powder, an iron-silicon-aluminum magnetic powder, an iron-silicon-chromium magnetic powder, an amorphous magnetic powder, and a nanocrystalline magnetic powder.

[0015] In one of the embodiments, the inner core layer is a metal blended fabric, and the metal blended fabric comprises stainless steel fibers, and the total mass fraction of the stainless steel fibers is greater than 8%.

[0016] In one of the embodiments, the diameter of the stainless steel fibers ranges from 1.5 to 30 μm.

[0017] In one of the embodiments, the second shielding layer comprises at least one of aluminum, copper, silver, nickel, chromium, and zinc.

[0018] In one of the embodiments, the shielding structure further comprises a support layer, and the support layer is arranged between the second shielding layer and the inner core layer, and the support layer is an organic material.

[0019] A tent, the tent comprising any one of the above electromagnetic shielding materials.

[0020] The electromagnetic shielding material has the advantages that the inner core layer with high mechanical strength and basic shielding effectiveness is arranged as a mechanical support core, the inner core layer provides basic mechanical support for the whole material by virtue of the high tearing strength thereof, and the inner core layer realizes basic electromagnetic shielding at a low frequency band by virtue of the metal component or magnetic guide characteristic thereof; the shielding structures arranged symmetrically on two sides of the inner core layer form a bidirectional cooperative shielding system, the first shielding layer bears a preliminary shielding effect, the conductive adhesive layer not only realizes the conductive continuity between the shielding layers to avoid the shielding effectiveness from being reduced due to insulation between the layers, but also enhances the bonding strength between the layers, and the second shielding layer provides further shielding effect, so that the layers cooperatively form a complete electromagnetic shielding and mechanical support integrated structure. The design of the electromagnetic shielding material not only guarantees the comprehensiveness of electromagnetic shielding by the cooperation of the inner core layer and the double-layer shielding structure, but also improves the overall mechanical reliability of the material by virtue of the high tearing strength of the inner core layer and the bonding design between the layers. The symmetric structure makes the material bear stress uniformly, and the material is not easy to deform or be damaged in the folding and erecting process of the tent, and the shielding performance and use durability are considered.

[0021] The tent has the advantages that the multi-layer shielding structure of the electromagnetic shielding material forms a closed electromagnetic shielding cavity, the cooperation of the inner core layer and the double-layer shielding structure is favorable for blocking the invasion of external electromagnetic waves, avoids the interference or damage of internal electronic information equipment, prevents the leakage of internal confidential electromagnetic signals, and can meet the GJB5792A-2021B level shielding requirement, so that a safe and stable electromagnetic environment is provided for the internal electronic information equipment, the confidential information leakage and electromagnetic interference are effectively prevented, the high mechanical reliability and lightweight design of the material improve the durability and portability of the tent, the erecting time is greatly shortened, the material is suitable for various use scenarios such as outdoor work, emergency support and confidential places, and the flexibility and adaptability of the material are good, the material is perfectly matched with the arched windproof structure and the door curtain sealing structure of the tent, and the shielding integrity and use practicability of the whole tent are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the application, and are incorporated herein for purposes of illustrating the illustrative embodiments of the present application and the explanations provided herein. The drawings are not intended to limit the present application, and are provided for purposes of explanation only.

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the accompanying drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and other accompanying drawings can be obtained by those skilled in the art without any creative effort on the basis of these accompanying drawings.

[0024] Figure 1 The structural schematic diagram of the electromagnetic shielding material described in an embodiment.

[0025] Figure 2 Structure diagram of electromagnetic shielding material described in another embodiment.

[0026] Explanation of reference signs:

[0027] 100, electromagnetic shielding material; 110, inner core layer; 120, first shielding layer; 130, conductive adhesive layer; 140, second shielding layer; 141, metal layer; 142, insulating layer; 150, support layer. DETAILED DESCRIPTION

[0028] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below in combination with the drawings. In the following description, a large number of specific details are set forth in order to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the concept of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0029] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0030] In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined with "first" and "second" can include at least one of the features explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0031] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In the present application, unless otherwise explicitly specified and limited, a first feature is "on" or "under" a second feature can mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "over", "above" and "on top of" the second feature can mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. The first feature "under", "below" and "underneath" the second feature can mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0033] It should be noted that when an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or there can be an intermediate element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intermediate element. The terms "vertical", "horizontal", "up", "down", "left", "right", and the like used herein are for illustrative purposes only and are not intended to be the only implementation.

[0034] Referring to Figure 1 , Figure 1 A structural diagram of an electromagnetic shielding material 100 in an embodiment of the present application is shown. The electromagnetic shielding material 100 provided by the embodiment of the present application includes an inner core layer 110 and a shielding structure. The tearing strength of the inner core layer 110 ranges from 35N to 75N, and the shielding effectiveness of the inner core layer 110 in the frequency band of 14kHz to 200kHz ranges from 3dB to 15dB. The shielding structure is at least two, and the two shielding structures are symmetrically arranged on opposite sides of the inner core layer 110. Each shielding structure includes a first shielding layer 120, a conductive adhesive layer 130 and a second shielding layer 140 arranged in layers, and the second shielding layer 140 is arranged closer to the inner core layer 110 relative to the conductive adhesive layer 130.

[0035] The electromagnetic shielding material 100 has the inner core layer 110 with high mechanical strength and basic shielding effectiveness as a mechanical support core, the inner core layer 110 provides basic mechanical support for the whole material by virtue of its high tear strength, and realizes low-frequency basic electromagnetic shielding by its metal component or magnetic permeability characteristics, the shielding structures symmetrically arranged on both sides of the inner core layer 110 form a bidirectional collaborative shielding system, the first shielding layer 120 bears the preliminary shielding effect, the conductive adhesive layer 130 not only realizes the conductive continuity between the shielding layers to avoid the shielding effectiveness from being reduced due to the insulation between the layers, but also enhances the interlayer bonding strength, the second shielding layer 140 provides further shielding effect, and the layers collaboratively form a complete electromagnetic shielding and mechanical support integrated structure. The design of the electromagnetic shielding material 100 not only guarantees the comprehensiveness of electromagnetic shielding through the collaborative action of the inner core layer 110 and the double-layer shielding structure, but also improves the overall mechanical reliability of the material by virtue of the high tear strength of the inner core layer 110 and the interlayer bonding design, the symmetrical structure makes the material bear force evenly, and the material is not easy to deform or damage during the folding and building of the tent, and the shielding performance and use durability are considered.

[0036] Optionally, the inner core can be a single-layer structure or a composite structure with two or more layers.

[0037] In one embodiment, the areal weight of the inner core layer 110 is 210-330 g / m 2 By controlling the areal weight of the inner core layer 110 in a relatively high range, it is ensured that the inner core layer 110 has sufficient material density and thickness to provide necessary rigid support and anti-deformation capability for the whole composite structure, so that the weight range can avoid the material being too thick and heavy on the premise of ensuring sufficient support strength, which is conducive to realizing the lightweight design of the tent material.

[0038] Specifically, the areal weight of the inner core layer 110 is directly related to the thickness, density and internal component distribution of the material, and the range of 210-330 g / m² can match the material composition of the metal blended fabric or the blended glue with magnetic powder, which not only ensures that the inner core layer 110 has sufficient thickness to accommodate conductive or magnetic components to form an effective basic shielding path, but also avoids material redundancy and increases the overall weight due to too high areal weight. The weight range can balance the mechanical properties, shielding performance and lightweight of the inner core layer 110, which can stably support a tear strength of 40-65 N and a low-frequency shielding effectiveness of 3-15 dB, and will not increase the overall weight of the tent due to its own weight, which is conducive to improving the portability and building efficiency of the tent, and the reasonable weight makes the material have good flexibility, which is suitable for the arc structure and folding requirements of the tent.

[0039] Optionally, the areal mass of the inner core layer 110 can be 210, 212, 215, 217, 219, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330 or any value therein, in g / m 2 .

[0040] In one embodiment, the areal mass of the first shielding layer 120 is 40-240 g / m 2 The first shielding layer 120 as the outer layer of the shielding structure preliminarily shields the unit, and the areal mass of 40-240 g / m2 corresponds to the reasonable fiber density or coating thickness of materials such as conductive cloth, which can ensure the formation of a continuous conductive network inside the material, realize basic shielding through reflection and absorption, and at the same time, the mass range makes the first shielding layer 120 have a certain structural strength, avoiding easy damage in the use process; such mass design can not only meet the shielding effectiveness requirements of the first shielding layer 120 in the 14 kHz and 200 kHz frequency bands, but also control the overall weight of the shielding structure, form a reasonable ratio with the mass of the inner core layer 110 and the second shielding layer 140, so that the surface density of the entire electromagnetic shielding material 100 is in a relatively optimal range, which does not affect the shielding performance, and improves the lightweight level of the material, and at the same time, the good structural strength is beneficial to prolong the service life of the material in the outdoor environment.

[0041] Specifically, the areal mass of the first shielding layer 120 can be 40, 50, 60, 70, 80, 90

[0042] 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240 or any value therein, in g / m 2 .

[0043] In one embodiment, the areal mass of the second shielding layer 140 is 125-145 g / m 2The second shielding layer 140, as a core shielding unit, needs to achieve efficient shielding through a higher proportion of conductive or magnetic components, and a gram per square meter weight of 125-145 g / m² can accommodate multiple layers of metal, insulating composite structures, or high-content conductive metal layers 141, ensuring that the thickness and density of the metal layer 141 are sufficient to achieve efficient reflection and absorption of electromagnetic waves, while also considering the flexibility of the material to avoid stiffness caused by excessive gram weight. In this way, this gram weight range allows the second shielding layer 140 to achieve a shielding effectiveness of 16-24 dB (14 kHz) and 40-50 dB (200 kHz), becoming the core shielding guarantee of the entire material, while coordinating with the gram weight of the first shielding layer 120 and the inner core layer 110 to maximize the shielding effectiveness of the overall material while maintaining good lightweight and flexibility, adapting to the installation and use of each part of the tent, and avoiding uneven stress on the tent support structure caused by excessive local weight.

[0044] In one embodiment, the tear strength of the laminated structure composed of the first shielding layer 120 and the conductive adhesive layer 130 is in the range of 20-25 N. The first shielding layer 120 itself has a certain tear strength, and the conductive adhesive layer 130 firmly combines the fibers or structural units of the first shielding layer 120 through penetration and adhesion, reducing interlayer slippage and significantly improving the tear resistance of the combined structure. The tear strength of 20-25 N can match the functional positioning of the first shielding layer 120, which not only bears the initial shielding but also has a certain mechanical protection capability. The mechanical properties of the combined structure complement the inner core layer 110 and the second shielding layer 140, avoiding tearing of the first shielding layer 120 due to individual stress, improving the overall mechanical reliability of the shielding structure, and effectively resisting tearing risks under repeated tent disassembly, outdoor wind, and other external forces, extending the service life of the material. At the same time, this tear strength range will not sacrifice the flexibility of the material due to excessive strengthening, ensuring that the material can be normally folded and stored.

[0045] Optionally, the second shielding layer 140 can be a single-layer structure or a multi-layer composite structure.

[0046] Please refer to Figure 2 , Figure 2A structural diagram of the electromagnetic shielding material 100 in another embodiment of the present application is shown. In another embodiment, the second shielding layer 140 includes a metal layer 141 and an insulating layer 142, which are at least two layers and are stacked in sequence. The metal layer 141 strongly reflects electromagnetic waves due to high conductivity, and the insulating layer 142 avoids direct contact between adjacent metal layers 141 to form a short circuit, while extending the propagation path of electromagnetic waves in the shielding layer, so that the electromagnetic waves are reflected and attenuated multiple times between the multiple metal layers 141. Compared with a single metal layer 141, the multiple alternating layers can significantly improve the shielding effect of electromagnetic waves of different frequency bands, especially the absorption and attenuation effect of low frequency bands. Thus, the multiple layer structure design can significantly improve the shielding effectiveness of the second shielding layer 140 through the synergistic effect of the metal layer 141 and the insulating layer 142, and can accurately meet the high shielding requirement of the low frequency band. The presence of the insulating layer 142 is beneficial to optimizing the flexibility of the material, avoiding brittle fracture of the metal layer 141 due to excessive thickness of a single layer, improving the bending resistance of the material, adapting to the arc structure of the tent and the repeated folding requirement, and the stability of the multiple layer structure is stronger, and the shielding performance does not easily attenuate after long-term use.

[0047] The metal layer 141 and the insulating layer 142 can be stacked in the following manner: the opposite two sides of the second shielding layer 140 are both metal layers 141, or the opposite two sides of the second shielding layer 140 are both insulating layers 142, or the opposite two sides of the second shielding layer 140 are a metal layer 141 and an insulating layer 142, respectively. The metal layer 141 can be arranged on one side of the inner core layer 110, or the metal layer 141 is arranged on one side of the conductive adhesive layer 130, and the other side is the insulating layer 142.

[0048] In one embodiment, the shielding effectiveness of the first shielding layer 120 at a frequency of 14 kHz is 5-15 dB, and the shielding effectiveness at 200 kHz is 10-34 dB. Specifically, the conductive network of the first shielding layer 120 mainly forms an electromagnetic reflection path through the continuous conductivity of the conductive fibers at a low frequency of 14 kHz. Since the wavelength of low-frequency electromagnetic waves is relatively long, the shielding effectiveness is relatively low. At a frequency of 200 kHz, the frequency of the electromagnetic wave is increased, the reflection effect of the conductive network is enhanced, and the polarization loss inside the material is increased, so that the shielding effectiveness is significantly improved. The parameter design is matched with the preliminary shielding positioning of the first shielding layer 120. The specific shielding effectiveness parameter enables the first shielding layer 120 to respond to electromagnetic waves of different low frequency bands, forming a gradient shielding effect, and complementing the high shielding effectiveness of the second shielding layer 140, so as to ensure that the shielding effectiveness of the entire material in the frequency range of 14 kHz-200 kHz continuously meets the standard, avoids the occurrence of a shielding blind area, and at the same time, the parameter range conforms to the performance characteristics of commonly used materials such as conductive cloth, which is beneficial to balancing performance and cost and facilitating large-scale production.

[0049] Optionally, the first shielding layer 110 can be a conductive cloth, a metal foil or other composite shielding material.

[0050] In one embodiment, the second shielding layer 140 has a shielding effectiveness of 13-24 dB at a frequency of 14 kHz and a shielding effectiveness of 32-50 dB at 200 kHz. The multi-layer metal, insulating layer 142 of the second shielding layer 140 absorbs electromagnetic waves at a low frequency of 14 kHz through hysteresis loss and multiple reflections, and the alternating arrangement of the metal layer 141 with high magnetic permeability and the insulating layer 142 can prolong the propagation path of electromagnetic waves and improve the absorption efficiency. At a frequency of 200 kHz, the high electrical conductivity of the metal layer 141 plays a dominant role in strongly reflecting electromagnetic waves, and the superposition effect of the multi-layer structure further improves the shielding effectiveness to achieve a high level of shielding effect. This parameter can match the shielding requirements of the electromagnetic shielding tent at low frequencies, especially the shielding effectiveness of 40-50 dB at 200 kHz, effectively compensating for the shielding shortcomings of the first shielding layer 120 and the inner core layer 110, so that the entire material meets the GJB5792A-2021 B-level shielding requirements, and can reliably protect internal electronic equipment from low-frequency electromagnetic interference while avoiding the leakage of internal confidential information, providing a safe use environment for key electronic information equipment.

[0051] Optionally, the inner core layer 110 includes at least one of a metal blended fabric, a metal composite material, an ultra-high molecular weight polyethylene fabric, an aramid fabric, a high-toughness nylon fabric, a high-toughness polyester fiber fabric, and a tear-resistant nylon fabric.

[0052] Specifically, when the inner core layer 110 is a metal blended fabric, the metal blended fabric forms a continuous conductive network through the interweaving of metal fibers, and uses the electrical conductivity of the metal to reflect and absorb electromagnetic waves. When the inner core layer 110 is a metal composite material, an electrically conductive path is formed by metal particles or fibers dispersed in the matrix. At the same time, the structural characteristics of the two materials can provide high mechanical strength to meet the tear strength requirements. In addition, such material selection enables the inner core layer 110 to achieve a low-frequency shielding effectiveness of 3-15 dB without the need for additional shielding components, and naturally has good mechanical properties, which can stably achieve a tear strength of 40-50 N, simplifying the structural design of the inner core layer 110 and reducing production complexity. Moreover, the metal blended fabric and the metal composite material both have good flexibility and processability, and can be cut and folded as needed to adapt to the shape requirements of different parts of the tent, such as the front gable and the arched facade, which is conducive to improving the versatility of the material.

[0053] In one embodiment, the inner core layer 110 includes a blended adhesive matrix and fillers mixed in the blended adhesive matrix. The fillers include at least one of nickel-iron alloy, permalloy, nickel-molybdenum magnetic powder, iron-silicon magnetic powder, iron-silicon-aluminum magnetic powder, iron-silicon-chromium magnetic powder, amorphous magnetic powder, and nanocrystalline magnetic powder. The blended adhesive matrix provides good adhesion and flexibility, enabling the fillers to be uniformly dispersed and form a stable structure. The selected fillers all have high magnetic permeability. In the low-frequency range of 14kHz to 200kHz, the magnetic powder efficiently absorbs electromagnetic waves through hysteresis loss and eddy current loss. At the same time, the uniform distribution of the magnetic powder in the matrix can enhance the structural strength of the inner core layer 110, improve tear resistance, and achieve synergy between mechanical properties and shielding performance. The introduction of magnetic powder filler is beneficial for specifically enhancing the low-frequency shielding capability of the inner core layer 110. Compared with the traditional single-material inner core layer 110, the shielding efficiency is significantly improved, which can stably reach 3~15dB. At the same time, the synergistic effect of the blended adhesive matrix and magnetic powder can ensure a tear strength of 40~50N, achieving a dual breakthrough in shielding and mechanical properties. Moreover, the material has good formability and can be processed into different thicknesses and shapes through molding, cutting and other processes to adapt to the usage needs of various parts of the tent. In addition, the blended adhesive matrix has a certain degree of weather resistance, which improves the applicability of the material in outdoor environments.

[0054] In one embodiment, the inner core layer 110 is a metal-blended fabric, which includes stainless steel fibers with a total mass fraction greater than 8%. For example, the inner core layer 110 is a stainless steel-blended fabric. Stainless steel fibers have good conductivity and mechanical strength. A mass fraction greater than 8% ensures that the fibers form a continuous and dense conductive network in the blended fabric, ensuring that electromagnetic waves can be effectively shielded through reflection and absorption. At the same time, the interweaving and entanglement between the fibers form a stable mechanical structure, significantly improving the tear resistance of the blended fabric. Thus, the material of the inner core layer 110 is conducive to achieving a precise balance between shielding effectiveness and mechanical properties. When the content is less than 8%, it is difficult for the stainless steel fibers to form a continuous conductive network, and the shielding effectiveness and tear strength cannot meet the standards. This ensures a low-frequency shielding effectiveness of 3~15dB and a tear strength of 40~50N, while retaining the material's good flexibility and weaving processability. In addition, the stainless steel fibers have excellent corrosion resistance, which can improve the service life of the inner core layer 110 in outdoor humid and dusty environments.

[0055] Specifically, the mass fraction of stainless steel fibers in the inner core layer 110 can be 8%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any value between these values. When the mass fraction is 100%, the inner core layer is pure stainless steel fiber cloth.

[0056] Optionally, the diameter of the stainless steel fibers is 1.5~30μm. Further, the length of the stainless steel fibers is 0.5~2mm. This ensures that the fibers are fully interwoven and wrapped with ordinary fibers during the blending process, forming a stable conductive network and mechanical support structure. It also prevents processing defects such as agglomeration and entanglement during spinning or weaving due to excessively long fibers, and avoids insufficient continuity of the conductive network and mechanical structure due to excessively short fibers. Furthermore, these length and diameter parameters ensure the molding quality and performance stability of the metal blended fabric, enabling the inner core layer 110 to achieve a shielding effectiveness of 3~15dB and a tear strength of 40~50N. It also improves the material's production feasibility and reduces the scrap rate during processing. In addition, the suitable fiber length and paper towel range make the blended fabric soft to the touch and more flexible, facilitating the folding, storage, and setup of tents, and reducing folding marks or damage caused by excessively stiff fibers.

[0057] In one embodiment, the second shielding layer 140 comprises at least one element selected from aluminum, copper, silver, nickel, chromium, and zinc. For example, the second shielding layer 140 is aluminum foil.

[0058] Specifically, elements such as aluminum, copper, and silver have extremely high conductivity, which can effectively block electromagnetic waves, especially high-frequency electromagnetic waves, through reflection. Elements such as nickel, chromium, and zinc have good corrosion resistance and wear resistance, which can protect the shielding layer from external environmental erosion and extend its service life. Different elements can be used alone or in combination as needed to form a metal layer 141 that has both high shielding effectiveness and weather resistance. The high conductivity elements ensure the high shielding effectiveness of the second shielding layer 140, meeting the performance requirements of 16~24dB (14kHz) and 40~50dB (200kHz). The corrosion-resistant elements help improve the durability of the material in outdoor sun, rain, and humid environments, and prevent the metal layer 141 from oxidizing and rusting, which would reduce the shielding effectiveness. Compared with a single metal element, this combination of elements enables the second shielding layer 140 to achieve a comprehensive improvement in shielding performance, weather resistance, and service life, which is suitable for the needs of long-term outdoor use of tents.

[0059] In one embodiment, the shielding structure further includes a support layer 150 disposed between the second shielding layer 140 and the inner core layer 110, wherein the support layer 150 is made of an organic material. The organic material disposed between the second shielding layer 140 and the inner core layer 110 provides a buffering effect.

[0060] An embodiment of the present invention also provides a tent comprising any one of the electromagnetic shielding materials 100 described above.

[0061] The aforementioned tent, by using the aforementioned electromagnetic shielding material 100, forms a sealed electromagnetic shielding cavity through its multi-layered shielding structure. The synergistic effect of the inner core layer 110 and the double-layer shielding structure effectively blocks external electromagnetic waves from intruding, preventing interference or damage to internal electronic information equipment. It also prevents the leakage of classified electromagnetic signals, meeting the GJB5792A-2021 Class B shielding requirements. This provides a safe and stable electromagnetic environment for internal electronic information equipment, effectively protecting against the leakage of classified information and electromagnetic interference. Furthermore, the material's high mechanical reliability and lightweight design enhance the tent's durability and portability, significantly reducing setup time. It is suitable for various usage scenarios such as outdoor operations, emergency response, and classified locations. The material's flexibility and adaptability perfectly complement the tent's arched windproof structure and door sealing structure, ensuring the overall shielding integrity and practicality of the tent.

[0062] To demonstrate the beneficial effects of the electromagnetic shielding material and tent provided in the embodiments of the present invention, the following description is provided in conjunction with several embodiments and comparative examples.

[0063] Test standards: Shielding effectiveness is tested according to GJB8820-2015 (Shielded Room Method), 14kHz, 200kHz, 10MHz~18GHz frequency bands; tear strength is tested according to GB / T3917.3-2009; areal density is tested according to GB / T4669-2008; flexibility is evaluated by observing whether delamination or cracking occurs after repeated folding 1000 times; tent setup time is recorded as the average time taken for 3 people to complete the setup; the overall shielding effectiveness of the tent is tested by the shielding performance of the cavity after the door curtain is closed.

[0064] Example 1

[0065] Inner core layer: Stainless steel blended fabric, stainless steel fiber mass fraction 10%, fiber length 5~16mm, tear strength 45N, shielding effectiveness 3~10dB at 14kHz~200kHz, areal density 220g / m²; Shielding structure: 2 layers, symmetrically arranged on both sides of the inner core layer, each layer consisting of a first shielding layer, a conductive adhesive layer, and a second shielding layer. First shielding layer: Conductive cloth, areal density 130g / m², shielding effectiveness 8dB at 14kHz, shielding effectiveness 18dB at 200kHz. Second shielding layer: Single-layer aluminum foil, areal density 135g / m², shielding effectiveness 20dB at 14kHz, shielding effectiveness 45dB at 200kHz; Tear strength of the first shielding layer combined with the conductive adhesive layer is 23N; Overall material areal density: 590g / m²;

[0066] Tent application: This material is used to make a 15㎡ arched tent, 5m long × 3m wide, with a door curtain equipped with shielding hook and loop fasteners.

[0067] Example 2

[0068] Inner core layer: The blended adhesive matrix is ​​an epoxy-polyurethane blended adhesive, mixed with nickel-iron alloy magnetic powder filler, with a tear strength of 42N, a shielding effectiveness of 5~14dB at 14kHz~200kHz, and a surface density of 215g / m². Shielding structure: Two layers, symmetrically arranged on both sides of the inner core layer. Each layer consists of a first shielding layer, a conductive adhesive layer, a second shielding layer, and a support layer. First shielding layer: Silver-plated nylon conductive cloth, surface density 125g / m², shielding effectiveness of 7dB at 14kHz and 17dB at 200kHz; Second shielding layer: Copper foil + polyimide insulating layer + copper foil, a three-layer alternating structure, surface density 140g / m², shielding effectiveness of 22dB at 14kHz and 50dB at 200kHz. The combined tear strength of the first shielding layer and conductive adhesive layer is 22N; overall material surface density: 580g / m².

[0069] Tent application: This material is used to make a 15㎡ arched tent, 5m long × 3m wide, with a door curtain equipped with shielding hook and loop fasteners.

[0070] Example 3

[0071] Inner core layer: Blended adhesive matrix mixed with nanocrystalline magnetic powder, tear strength 48N, shielding effectiveness 6~15dB at 14kHz~200kHz, areal density 225g / m²; Shielding structure: 2 layers, symmetrically arranged on both sides of the inner core layer, each layer consisting of a first shielding layer, a conductive adhesive layer, a second shielding layer, and a support layer; First shielding layer: Copper-plated nylon conductive cloth, areal density 135g / m², shielding effectiveness 9dB at 14kHz, shielding effectiveness 19dB at 200kHz; Second shielding layer: Aluminum foil + PET insulation layer + aluminum foil + PET insulation layer + aluminum foil, 5 alternating layers, total thickness 30μm, areal density 142g / m², shielding effectiveness 24dB at 14kHz, shielding effectiveness 54dB at 200kHz; Support layer: Modified PET film; Tear strength of the first shielding layer combined with the conductive adhesive layer 24N; Overall material areal density: 600g / m².

[0072] Tent application: This material is used to make a 15㎡ arched tent, 5m long × 3m wide, with a door curtain equipped with shielding hook and loop fasteners.

[0073] Example 4

[0074] Inner core layer: Metal-blended fabric, 32% stainless steel fiber by mass, fiber length 2mm, tear strength 50N, shielding effectiveness 4~12dB at 14kHz~200kHz, areal density 230g / m²; Shielding structure: 2 layers, symmetrically arranged on both sides of the inner core layer, each layer consisting of a first shielding layer, a conductive adhesive layer, a second shielding layer, and a support layer; First shielding layer: Conductive cloth, areal density 140g / m², shielding effectiveness 10dB at 14kHz, shielding effectiveness 20dB at 200kHz; Second shielding layer: Aluminum foil + PET insulation layer + aluminum foil + PET insulation layer + aluminum foil, 5-layer alternating structure, areal density 145g / m², shielding effectiveness 23dB at 14kHz, shielding effectiveness 49dB at 200kHz; Support layer: Modified PET film; Tear strength of the first shielding layer combined with the conductive adhesive layer 25N; Overall material areal density: 610g / m².

[0075] Tent application: This material is used to make a 15㎡ arched tent, 5m long × 3m wide, with a door curtain equipped with shielding hook and loop fasteners.

[0076] Example 5

[0077] Inner core layer: Metal-blended fabric, 58% stainless steel fiber by mass, fiber length 0.5mm, tear strength 40N, shielding effectiveness 6~15dB at 14kHz~200kHz, areal density 210g / m²; Shielding structure: 2 layers, symmetrically arranged on both sides of the inner core layer, each layer consisting of a first shielding layer, a conductive adhesive layer, a second shielding layer, and a support layer; First shielding layer: Silver-plated nylon conductive fabric, areal density 120g / m², shielding effectiveness 5dB at 14kHz, shielding effectiveness 15dB at 200kHz; Second shielding layer: Copper-aluminum composite foil + polyimide insulating layer + copper-aluminum composite foil, 3-layer alternating structure, areal density 125g / m², shielding effectiveness 23dB at 14kHz, shielding effectiveness 52dB at 200kHz; Support layer: Polyimide film; Tear strength of the first shielding layer combined with the conductive adhesive layer 20N; Overall material areal density: 560g / m².

[0078] Tent application: This material is used to make a 15㎡ arched tent, 5m long × 3m wide, with a door curtain equipped with shielding hook and loop fasteners.

[0079] Comparative Example 1

[0080] Inner core layer: Metal-blended fabric, 2% stainless steel fiber by mass, tear strength 23N, shielding effectiveness 3~8dB at 14kHz~200kHz, areal density 130g / m²; Shielding structure: 2 layers, symmetrically arranged on both sides of the inner core layer, each layer consisting of a first shielding layer, a conductive adhesive layer, and a second shielding layer; First shielding layer: Conductive fabric, areal density 130g / m², shielding effectiveness 8dB at 14kHz, shielding effectiveness 18dB at 200kHz; Second shielding layer: Single-layer 30μm aluminum foil, areal density 134g / m², shielding effectiveness 18dB at 14kHz, shielding effectiveness 42dB at 200kHz; Tear strength of the first shielding layer combined with the conductive adhesive layer is 23N; Overall material areal density: 588g / m².

[0081] Tent application: This material is used to make a 15㎡ arched tent, 5m long × 3m wide, with a door curtain equipped with shielding hook and loop fasteners.

[0082] Comparative Example 2

[0083] Inner core layer: Ordinary polyester fiber cloth, tear strength 35N, shielding effectiveness 0~2dB at 14kHz~200kHz, areal density 200g / m²; Shielding structure: 2 layers, symmetrically arranged on both sides of the inner core layer, each layer consisting of a first shielding layer, a conductive adhesive layer, a second shielding layer, and a support layer; First shielding layer: Conductive cloth, areal density 130g / m², shielding effectiveness 8dB at 14kHz, shielding effectiveness 18dB at 200kHz; Second shielding layer: Aluminum foil + PET insulation layer + aluminum foil, 3-layer alternating structure, areal density 135g / m², shielding effectiveness 20dB at 14kHz, shielding effectiveness 45dB at 200kHz; Support layer: Ordinary PET film (unmodified); Tear strength of the first shielding layer and conductive adhesive layer combination 23N; Overall material areal density: 575g / m².

[0084] Tent application: This material is used to make a 15㎡ arched tent, 5m long × 3m wide, with a door curtain equipped with shielding hook and loop fasteners.

[0085] Comparative Example 3

[0086] Inner core layer: Metal-blended fabric, 5% stainless steel fiber by mass, fiber length 1mm, tear strength 28N, shielding effectiveness 2~4dB at 14kHz~200kHz, areal density 210g / m²; Shielding structure: 2 layers, symmetrically arranged on both sides of the inner core layer, each layer consisting of a first shielding layer, a conductive adhesive layer, a second shielding layer, and a support layer; First shielding layer: Conductive cloth, areal density 130g / m², shielding effectiveness 8dB at 14kHz, shielding effectiveness 18dB at 200kHz; Second shielding layer: Aluminum foil + PET insulation layer + aluminum foil, 3-layer alternating structure, areal density 135g / m², shielding effectiveness 20dB at 14kHz, shielding effectiveness 45dB at 200kHz; Support layer: Modified PET film; Tear strength of the first shielding layer combined with the conductive adhesive layer is 23N; Overall material areal density: 585g / m².

[0087] Tent application: This material is used to make a 15㎡ pointed tent, 5m long x 3m wide, with a traditional multi-pole frame and a door curtain with a regular zipper.

[0088] The electromagnetic shielding materials described in the above embodiments and comparative examples were tested, and the test results are shown in Table 1 below:

[0089] Table 1

[0090]

[0091] Verification Conclusion: The technical solutions adopted in Examples 1-5 achieve shielding effectiveness ≥31dB in the 14kHz band and ≥65dB in the 200kHz band, both meeting the requirements of GJB5792A-2021B level. Tear strength ≥40N, areal density ≤610g / m², no delamination or cracking after 1000 folds, and tent setup time ≤14min, achieving synergistic optimization of shielding effectiveness, mechanical reliability, lightweight design, and setup efficiency. In contrast, Comparative Example 1, due to the lack of an inner core layer material, only barely meets the low-frequency shielding standard; Comparative Example 2 lacks a metal / magnetic powder inner core, and Comparative Example 3 has insufficient stainless steel fiber content, resulting in relatively low shielding effectiveness and weak mechanical properties. The traditional pointed tent setup time for Comparative Example 3 reaches 35min. In summary, this technical solution, through the synergistic design of the inner core layer and shielding structure, specifically addresses the problems of low low-frequency shielding, poor mechanical properties, and cumbersome tent setup associated with traditional materials.

[0092] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An electromagnetic shielding material, characterized in that, The electromagnetic shielding material includes: The inner core layer has a tear strength range of 35~75N and a shielding effectiveness range of 3~15dB in the frequency band of 14kHz~200kHz. The shielding structure comprises at least two shielding structures, which are symmetrically arranged on opposite sides of the inner core layer. Each shielding structure includes a first shielding layer, a conductive adhesive layer, and a second shielding layer stacked together, with the second shielding layer disposed close to the inner core layer relative to the conductive adhesive layer.

2. The electromagnetic shielding material according to claim 1, characterized in that, The inner core layer has a basis weight of 210~330 g / m². 2 ; and / or, The basis weight of the first shielding layer is 40~240 g / m². 2 ; and / or, The second shielding layer has a basis weight of 125~145 g / m². 2 .

3. The electromagnetic shielding material according to claim 1, characterized in that, The tear strength of the laminated structure consisting of the first shielding layer and the conductive adhesive layer is in the range of 20~25N.

4. The electromagnetic shielding material according to claim 1, characterized in that, The second shielding layer includes a metal layer and an insulating layer, wherein the metal layer and the insulating layer are each at least two layers and are stacked sequentially.

5. The electromagnetic shielding material according to claim 1, characterized in that, The first shielding layer has a shielding effectiveness of 5~15dB at 14kHz; and a shielding effectiveness of 10~34dB at 200kHz; and / or, The shielding effectiveness of the second shielding layer is 13~24dB at a frequency of 14kHz and 32~50dB at a frequency of 200kHz.

6. The electromagnetic shielding material according to claim 1, characterized in that, The inner core layer includes at least one of metal-blended fabric and metal composite material.

7. The electromagnetic shielding material according to claim 6, characterized in that, The inner core layer includes a blended adhesive matrix and fillers mixed in the blended adhesive matrix. The fillers include at least one of nickel-iron alloy, permalloy, nickel-molybdenum magnetic powder, iron-silicon magnetic powder, iron-silicon-aluminum magnetic powder, iron-silicon-chromium magnetic powder, amorphous magnetic powder, and nanocrystalline magnetic powder.

8. The electromagnetic shielding material according to claim 6, characterized in that, The inner core layer is a metal-blended fabric, which includes stainless steel fibers, and the total mass fraction of the stainless steel fibers is greater than 8%; and / or, the diameter of the stainless steel fibers is 1.5~30μm.

9. The electromagnetic shielding material according to claim 1, characterized in that, The second shielding layer comprises at least one element selected from aluminum, copper, silver, nickel, chromium, and zinc; and / or, The shielding structure further includes a support layer, which is disposed between the second shielding layer and the inner core layer, and the support layer is made of organic material.

10. A tent, characterized in that, The tent comprises any one of the electromagnetic shielding materials according to claims 1-9.

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