Modularized full-spectrum efficient electromagnetic shielding flexible fabric and preparation method therefor

Abstract

The present invention belongs to the field of the design and preparation of electromagnetic shielding materials. Disclosed are a modularized full-spectrum efficient electromagnetic shielding flexible fabric and a preparation method therefor. The preparation method of the present invention comprises the following steps: (1) subjecting a fabric to a metal deposition treatment by using a magnetron sputtering system, so as to obtain a flexible conductive fabric A; (2) subjecting the surface of a polymer thin film to a metal deposition treatment by using a vacuum coating technology, so as to obtain a high-toughness conductive thin film B; (3) uniformly mixing a carbon-based wave-absorbing material, a polymer and a solvent, and curing the mixture, so as to obtain a wave-absorbing layer C having a certain thickness; and (4) subjecting the functional modules obtained in step (1), step (2) and step (3) to specific permutation, combination and packaging, so as to obtain a modularized full-spectrum electromagnetic shielding flexible composite fabric.

Description

A modular full-spectrum high-efficiency electromagnetic shielding flexible fabric and its preparation method Technical Field

[0001] The present invention belongs to the field of shielding material design and preparation, and specifically relates to a modular full-spectrum high-efficiency electromagnetic shielding flexible fabric and a preparation method thereof. Background Art

[0002] High-efficiency modular electromagnetic shielding flexible fabric is a material that can significantly reduce the intensity of electromagnetic radiation in a variety of application environments by appropriately adjusting the combination of shielding modules according to different application scenarios. The effective shielding of multi-band electromagnetic wave pollution by modular full-spectrum high-efficiency electromagnetic shielding flexible fabric has very important practical value in military, civilian, and electronic components. At the same time, the multi-modular and multi-combination product characteristics meet the development requirements of various industries to effectively reduce electromagnetic wave pollution in the environment while maintaining appropriate technical costs. Therefore, the research and development of modular full-spectrum high-efficiency electromagnetic shielding flexible fabric is of great significance. Existing electromagnetic shielding materials have poor electromagnetic shielding effects in multiple spectrum bands. This is mainly reflected in the difficulty in effectively shielding low-frequency electromagnetic waves and the inability to adaptively adjust the composition of the shielding material according to different application scenarios, resulting in high production costs and ineffective shielding performance.

[0003] Summary of the Invention [Technical Issues]

[0004] At present, the application spectrum of existing electromagnetic shielding composite materials is limited, and it is difficult to achieve limited shielding in the low-frequency band; and it is impossible to make appropriate modular adjustments to multi-layer shielding materials according to different application scenarios, resulting in a high application cost of this type of shielding material in multiple scenarios.

[0005] [Technical solution]

[0006] To address the above issues, the present invention first deposits a metal layer with excellent conductivity on the fabric surface using magnetron sputtering technology to produce a flexible conductive fabric A. Subsequently, a predetermined thickness of metal is deposited on the surface of a polymer film using vacuum coating technology to produce a conductive film B that effectively shields low-frequency electromagnetic waves. Finally, a carbon-based absorbing material and a polymer are synergistically combined to form an absorbing layer C that effectively absorbs high-frequency electromagnetic waves. By varying the thickness of the metal layer on the fabric or film surface and the content of the carbon-based absorbing material in the absorbing layer, fabrics, films, or coatings with varying electromagnetic parameters and shielding or absorption properties are achieved. These layers are then assembled and packaged in sequence to create a modular, full-spectrum electromagnetic shielding composite fabric.

[0007] The first object of the present invention is to provide a method for preparing a modular full-spectrum electromagnetic shielding flexible composite fabric, comprising the following steps:

[0008] (1) Preparation of conductive fabric A

[0009] A magnetron sputtering system is used to deposit metal on the fabric surface to obtain a flexible conductive fabric A. The magnetron sputtering target, sputtering time, and sputtering power are varied to prepare conductive fabrics with different types of metals and different deposition thicknesses.

[0010] (2) Preparation of conductive film B

[0011] A high-toughness conductive film B is obtained by performing metal deposition on the surface of the polymer film using a vacuum coating method. The vacuum coating target, coating time, and coating power are varied to prepare conductive films of different metal types and different deposition thicknesses.

[0012] (3) Preparation of absorbing layer C

[0013] The carbon-based absorbing material, polymer and solvent are mixed, stirred and dissolved, and then poured into a specified mold for curing to obtain an absorbing layer C of a certain thickness; wherein the amount of the carbon-based absorbing material is changed to prepare carbon-based absorbing layers with different electromagnetic parameters and absorbing capabilities;

[0014] (4) Preparation of full-spectrum electromagnetic shielding fabrics

[0015] The conductive fabric A, conductive film B and absorbing layer C obtained in step (1), step (2) and step (3) are arranged, combined and packaged to obtain the modular full-spectrum electromagnetic shielding flexible composite fabric.

[0016] In one embodiment of the present invention, the fabric described in step (1) is one or a blend of several fibers selected from the group consisting of cotton, linen, wool, silk, asbestos, viscose, polyamide, polyester, acrylic, spandex, velvet, polypropylene, and polyvinyl chloride.

[0017] Preferably, the fabric in step (1) is polyester.

[0018] In one embodiment of the present invention, the thickness of the fabric in step (1) is 0.05 mm to 2 mm.

[0019] Preferably, the thickness of the fabric in step (1) is 0.1 mm.

[0020] In one embodiment of the present invention, the target material for magnetron sputtering in step (1) is one of the metals nickel (Ni), titanium (Ti), zinc (Zn), chromium (Cr), magnesium (Mg), niobium (Nb), tin (Sn), aluminum (Al), indium (In), iron (Fe), zirconium (Zr), copper (Cu), germanium (Ge), silver (Ag), cobalt (Co), gold (Au), tungsten (W), or an alloy thereof.

[0021] Preferably, the metal target material in step (1) is nickel (Ni).

[0022] In one embodiment of the present invention, the sputtering time of the magnetron sputtering in step (1) is 10-30 minutes.

[0023] Preferably, the sputtering time in step (1) is 20 minutes.

[0024] In one embodiment of the present invention, the sputtering power of the magnetron sputtering in step (1) is 50-150W.

[0025] Preferably, the sputtering power in step (1) is 100W.

[0026] In one embodiment of the present invention, the surface metal thickness of the conductive fabric A in step (1) is 0.1-1 μm.

[0027] Preferably, the surface metal thickness of the conductive fabric A in step (1) is 0.3-0.5 μm.

[0028] In one embodiment of the present invention, the polymer film described in step (2) is one or more of cellulose (CA / CN), regenerated cellulose (RC), polyamide (nylon 6, nylon 66), polysulfone (PS), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polypropylene (PP), and polyester (PET).

[0029] Preferably, the polymer film described in step (2) is polyester PET.

[0030] In one embodiment of the present invention, the thickness of the polymer film in step (2) is 0.05 mm to 2 mm.

[0031] Preferably, the polymer film in step (1) has a thickness of 0.1 mm.

[0032] In one embodiment of the present invention, the target material for the vacuum coating in step (2) is one of the metals nickel (Ni), titanium (Ti), zinc (Zn), chromium (Cr), magnesium (Mg), niobium (Nb), tin (Sn), aluminum (Al), indium (In), iron (Fe), zirconium (Zr), copper (Cu), germanium (Ge), silver (Ag), cobalt (Co), gold (Au), tungsten (W), or their alloys.

[0033] Preferably, the target material for the vacuum coating in step (2) is aluminum (Al).

[0034] In one embodiment of the present invention, the vacuum coating time in step (2) is 5-20 minutes.

[0035] Preferably, the vacuum coating time in step (2) is 10 minutes.

[0036] In one embodiment of the present invention, the power of the vacuum coating in step (2) is 100-300W.

[0037] Preferably, the power of the vacuum coating in step (2) is 200W.

[0038] In one embodiment of the present invention, the surface metal thickness of the conductive film B in step (2) is 0.1-1 μm.

[0039] Preferably, the surface metal thickness of the conductive film B in step (2) is 0.15-0.3 μm.

[0040] In one embodiment of the present invention, the carbon-based absorbing material in step (3) is one or more of carbon nanotubes and their derivatives, graphene and its derivatives, carbon black and its derivatives, MXene and its derivatives, carbon quantum dots and their derivatives, and fullerene and its derivatives.

[0041] Preferably, the carbon-based absorbing material in step (3) is graphene nanosheets.

[0042] In one embodiment of the present invention, the polymer in step (3) is one or more of polypropylene (PP), polyethylene (PP), polyvinyl chloride (PVC), polyester (PET), polyvinylidene fluoride (PVDF), polytetrachloroethylene (PTFE), and polyethylene vinyl acetate (EVA).

[0043] Preferably, the polymer in step (3) is polyethylene vinyl acetate (EVA).

[0044] In one embodiment of the present invention, the solvent in step (3) is one or more of ethanol, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), acetone, N-methylmorpholine oxide (NMMO), room temperature plasma (AMIMCI), formic acid, acetic acid, trifluoroacetic acid (TFA), trifluoroethanol (TFE), chloroform (TCM), dichloromethane (DCM), hexafluoroisopropanol (HFIP), and tetrahydrofuran (THF).

[0045] Preferably, the solvent in step (3) is dichloromethane.

[0046] In one embodiment of the present invention, the uniform mixing in step (3) is stirring for 2-4 hours.

[0047] In one embodiment of the present invention, the mass fraction of the polymer in the solvent in step (3) is 10-30 wt.%.

[0048] Preferably, the concentration of the polymer in step (3) is 20 wt.%.

[0049] In one embodiment of the present invention, the concentration of the carbon-based absorbing material in step (3) is 10 wt.%-50 wt.%.

[0050] Preferably, the concentration of the carbon-based absorbing material in step (3) is 25 wt.%.

[0051] In one embodiment of the present invention, the thickness of the absorbing layer in step (3) is 0.1 mm to 2 mm.

[0052] Preferably, the thickness of the absorbing layer in step (3) is 0.15-0.3 mm.

[0053] In one embodiment of the present invention, the conductive fabric A, the conductive film B, and the absorbing layer C in step (4) are arranged in the order of one or more of CBA, CAB, ACB, ACA, BCB, CAC, CBC, CBCA, CACB, ACBCB, BCACA, ACBCA, BCACB, CBCAC, and CACBC.

[0054] Preferably, the permutation and combination order in step (4) is CBCAC.

[0055] In one embodiment of the present invention, the packaging in step (4) is one or more of high-temperature pressure packaging, plastic packaging, and plastic shell packaging.

[0056] Preferably, the packaging method in step (4) is high-temperature pressure packaging.

[0057] In one embodiment of the present invention, the packaging temperature in step (4) is 100-200°C.

[0058] In one embodiment of the present invention, the packaging time in step (4) is 5-20 minutes.

[0059] In one embodiment of the present invention, the packaging pressure in step (4) is 2-20 MPa.

[0060] Preferably, the packaging temperature in step (4) is 150° C., the packaging time is 10 min, and the packaging pressure is 10 MPa.

[0061] In one implementation method of the present invention, the thickness of the full-spectrum electromagnetic shielding fabric in step (4) is 0.1 mm to 5 mm.

[0062] Preferably, the thickness of the full-spectrum electromagnetic shielding fabric in step (4) is 0.5 mm.

[0063] In one implementation method of the present invention, the conductive fabric A, the conductive film B, and the absorbing layer C in the modular full-spectrum electromagnetic shielding flexible composite fabric work together, wherein the surface metal thickness of A is 0.3-0.5 μm, the surface metal thickness of B is 0.15-0.3 μm, and the thickness of the absorbing layer is 0.15-0.3 mm; and when the surface metal thickness of A is 0.5 μm, the surface metal thickness of B cannot be 0.3 μm and the thickness of the absorbing layer cannot be 0.15 mm at the same time.

[0064] The second purpose of the present invention is to prepare a full-spectrum electromagnetic shielding fabric based on the above method.

[0065] The third object of the present invention is to provide the application of the above-mentioned full-spectrum electromagnetic shielding fabric in the fields of military and electronic components. [Beneficial Effects]

[0066] The present invention addresses the problems of existing electromagnetic shielding materials, such as the difficulty in effectively shielding electromagnetic waves across the entire spectrum and the high cost associated with the inability to adapt the shielding materials to various application environments. The present invention designs and prepares a highly efficient modular full-spectrum electromagnetic shielding flexible fabric. The modular full-spectrum electromagnetic shielding flexible fabric can effectively shield high-, medium-, and low-frequency electromagnetic waves, and each shielding module can be adaptively adjusted according to different application scenarios. The various modular full-spectrum electromagnetic shielding flexible fabrics prepared by the method described in the present invention have excellent shielding effects, significantly superior to most current shielding materials. Furthermore, the shielding modules can be adjusted according to different application scenarios, significantly outperforming most current shielding materials in terms of cost control. DETAILED DESCRIPTION

[0067] The following describes preferred embodiments of the present invention. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0068] Source of raw materials

[0069] Polyethylene vinyl acetate was obtained from Shanghai MacLean Biochemical Technology Co., Ltd., and graphene nanosheets were purchased from Nanjing Xianfeng Nanotechnology Co., Ltd.

[0070] Test method:

[0071] Electromagnetic shielding effectiveness (window method): The electromagnetic shielding effectiveness of the samples in the examples and comparative examples was tested according to the test methods specified in GJB / Z 158-2011 and GJB 5792-2006.

[0072] Example 1

[0073] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 20 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.5 μm.

[0074] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0075] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0076] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of CBCAC, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150° C., the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0077] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of the modular full-spectrum electromagnetic shielding flexible fabric obtained in Example 1 in various frequency bands is shown in Table 1, indicating excellent full-spectrum electromagnetic shielding performance.

[0078] Table 1 Electromagnetic shielding effectiveness in different frequency bands

[0079] Example 2

[0080] Example 2 changes the metal thickness on the surface of the conductive polyester fabric in step (1) of Example 1.

[0081] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0082] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0083] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0084] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of CBCAC, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150° C., the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0085] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 2 in various frequency bands is shown in Table 2, indicating excellent full-spectrum electromagnetic shielding performance.

[0086] Table 2 Electromagnetic shielding effectiveness in different frequency bands

[0087] Example 3

[0088] In Example 3, the metal thickness on the surface of the polymer film in Example 1 is changed.

[0089] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 20 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.5 μm.

[0090] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 5 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al), and then perform surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.15 μm.

[0091] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0092] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of CBCAC, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150° C., the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0093] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 3 in various frequency bands is shown in Table 3, indicating excellent full-spectrum electromagnetic shielding performance.

[0094] Table 3 Electromagnetic shielding effectiveness in different frequency bands

[0095] Example 4

[0096] In Example 4, the thickness of the absorbing layer in Example 1 is changed.

[0097] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 20 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.5 μm.

[0098] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0099] (3) A 10 g mixed solution consisting of 2 g of polyethylene-vinyl acetate (EVA) and 2.5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.3 mm absorbing layer C.

[0100] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of CBCAC, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150° C., the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0101] (5) After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 4 in each frequency band is shown in Table 4, which shows that it has excellent full-spectrum electromagnetic shielding performance.

[0102] Table 4 Electromagnetic shielding effectiveness in different frequency bands

[0103] Example 5

[0104] Example 5 changes the arrangement and combination order of the electromagnetic shielding modules A, B, and C in Example 1.

[0105] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 20 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.5 μm.

[0106] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0107] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0108] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of ACBCA, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150°C, the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0109] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 5 in various frequency bands is shown in Table 5, which shows excellent full-spectrum electromagnetic shielding performance.

[0110] Table 5 Electromagnetic shielding effectiveness in different frequency bands

[0111] Example 6

[0112] Example 6 changes the arrangement and combination order of the electromagnetic shielding modules A, B, and C in Example 1.

[0113] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0114] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0115] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0116] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of BCACB, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150°C, the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0117] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 6 in various frequency bands is shown in Table 6, which shows excellent full-spectrum electromagnetic shielding performance.

[0118] Table 6 Electromagnetic shielding effectiveness in different frequency bands

[0119] Example 7

[0120] Example 7 changes the arrangement and combination order of the electromagnetic shielding modules A, B, and C in Example 1.

[0121] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0122] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0123] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0124] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of ACBCB, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150° C., the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0125] (5) After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example (7) in each frequency band is shown in Table 7, which shows that it has excellent full-spectrum electromagnetic shielding performance.

[0126] Table 7 Electromagnetic shielding effectiveness in different frequency bands

[0127] Example 8

[0128] Example 8 changes the arrangement and combination order of the electromagnetic shielding modules A, B, and C in Example 1.

[0129] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0130] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0131] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0132] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of BCACA, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150°C, the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0133] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 8 in various frequency bands is shown in Table 8, which shows excellent full-spectrum electromagnetic shielding performance.

[0134] Table 8 Electromagnetic shielding effectiveness in different frequency bands

[0135] Example 9

[0136] Example 9 changes the arrangement and combination order of the electromagnetic shielding modules A, B, and C in Example 1.

[0137] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0138] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0139] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0140] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of CBCA, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150°C, the packaging pressure is 20 MPa, and the packaging time is 10 minutes.

[0141] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 9 in each frequency band is shown in Table 9, which shows excellent full-spectrum electromagnetic shielding performance.

[0142] Table 9 Electromagnetic shielding effectiveness in different frequency bands

[0143] Example 10

[0144] Example 10 changes the arrangement and combination order of the electromagnetic shielding modules A, B, and C in Example 1.

[0145] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0146] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0147] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0148] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer C obtained in step (1), step (2), and step (3) are combined in the order of CACB, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150°C, the packaging pressure is 20 MPa, and the packaging time is 10 minutes.

[0149] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Example 10 in various frequency bands is shown in Table 10, which shows excellent full-spectrum electromagnetic shielding performance.

[0150] Table 10 Electromagnetic shielding effectiveness in different frequency bands

[0151] Comparative Example 1

[0152] Comparative Example 1 is a comparative example of Example 1, except that the magnetron sputtering metal deposition process on the polyester fabric surface is missing.

[0153] (1) The 10 cm × 10 cm polyester fabric that has not undergone the magnetron sputtering metal deposition process is recorded as A*

[0154] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0155] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0156] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer CBCA*C obtained in step (1), step (2), and step (3) are combined in the order of arrangement, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150° C., the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0157] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Comparative Example 1 in each frequency band is shown in Table 11, which shows excellent full-spectrum electromagnetic shielding performance.

[0158] Table 11 Electromagnetic shielding effectiveness in different frequency bands

[0159] Comparative Example 2

[0160] Comparative Example 1 is a comparative example of Example 1, but lacks the process of vacuum plating and depositing metal on the surface of the PET film.

[0161] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0162] (2) The 10 cm × 10 cm PET film that has not undergone the vacuum metal deposition process is recorded as B*

[0163] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0164] (4) The conductive polyester fabric A of specified size, the conductive metal PET film B, and the absorbing layer CB*CAC obtained in step (1), step (2), and step (3) are combined in the order of arrangement, and then high-temperature pressure packaging is performed to obtain a modular full-spectrum electromagnetic shielding flexible fabric, wherein the packaging temperature at both ends is 150°C, the packaging pressure is 20 MPa, and the packaging time is 10 min.

[0165] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of Comparative Example 2 in each frequency band is shown in Table 12, which shows excellent full-spectrum electromagnetic shielding performance.

[0166] Table 12 Electromagnetic shielding effectiveness in different frequency bands

[0167] Comparative Example 3

[0168] Comparative Example 3 is a comparison with Example 1, and lacks the high-temperature hot pressing packaging process.

[0169] (1) Place the polyester fabric with a thickness of 0.1 mm and a size of 10 cm × 10 cm to be treated in a magnetron sputtering system, adjust the sputtering time to 10 min, the sputtering power to 100 W, and the metal target material to nickel (Ni) and then perform surface metal deposition to obtain a conductive polyester fabric A with a surface metal thickness of 0.3 μm.

[0170] (2) Place a 10 cm × 10 cm PET film with a thickness of 0.1 mm to be processed in a vacuum coating system, adjust the vacuum coating time to 10 min, the vacuum coating power to 200 W, and the metal target material to aluminum (Al) for surface metal coating to obtain a conductive metal PET film B with a surface metal film thickness of 0.3 μm.

[0171] (3) A 20 g mixed solution consisting of 4 g of polyethylene-vinyl acetate (EVA) and 5 g of graphene nanosheets and dichloromethane was mixed and stirred for 3 h to completely dissolve the polyethylene-vinyl acetate and evenly disperse the graphene nanosheets, forming a uniform mixed solution of polyethylene-vinyl acetate and graphene nanosheets with mass fractions of 20 wt.%, 25 wt.%, respectively. After standing for 2 h to defoam, it was poured into a custom mold of 10 cm × 10 cm and a depth of 0.5 mm, and then dried at room temperature to obtain a 0.15 mm absorbing layer C.

[0172] After testing the electromagnetic shielding effectiveness using the window method, the shielding effectiveness of electromagnetic shielding modules A, B, and C in comparative example 3 in each frequency band is shown in Table 13, which shows excellent full-spectrum electromagnetic shielding performance.

[0173] Table 13 Electromagnetic shielding effectiveness in different frequency bands

[0174] In combination with the various embodiments and comparative examples, the present invention is based on a specific arrangement and combination of multiple modules such as conductive fabric A, conductive film B, and absorbing layer C. The cooperation between the multiple modules can achieve better full-spectrum electromagnetic shielding performance in the low, medium, and high frequency bands.

[0175] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a modular full-spectrum electromagnetic shielding flexible composite fabric, characterized in that: The steps include: (1) Preparation of conductive fabric A The metal deposition treatment was performed on the fabric surface by using a magnetron sputtering system to obtain a flexible conductive fabric A; (2) Preparation of conductive film B The surface of the polymer film is subjected to metal deposition treatment by vacuum coating to obtain a highly tough conductive film B; (3) Preparation of the absorbing layer C The carbon-based absorbing material, polymer and solvent are mixed, stirred and dissolved, and then poured into a specified mold for curing to obtain an absorbing layer C; (4) Preparation of full-spectrum electromagnetic shielding fabrics The conductive fabric A, conductive film B and absorbing layer C obtained in step (1), step (2) and step (3) are arranged, combined and packaged to obtain the modular full-spectrum electromagnetic shielding flexible composite fabric.

2. The method according to claim 1, characterized in that In step (4), the conductive fabric A, the conductive film B, and the absorbing layer C are arranged in the order of CBA, CAB, ACB, ACA, BCB, CAC, CBC, CBCA, CACB, ACBCB, BCACA, ACBCA, BCACB, CBCAC, and CACBC.

3. The method according to claim 1, characterized in that: The fabric described in step (1) is one or more fiber blends of cotton, linen, wool, silk, asbestos, viscose, nylon, polyester, acrylic, spandex, polypropylene, and chloroprene.

4. The method according to claim 1, characterized in that: The fabric thickness in step (1) is 0.05 mm to 2 mm.

5. The method according to claim 1, characterized in that The target material of the magnetron sputtering in step (1) is one of the metals nickel, titanium, zinc, chromium, magnesium, niobium, tin, aluminum, indium, iron, zirconium, copper, germanium, silver, cobalt, gold, tungsten or their alloys.

6. The method according to claim 1, characterized in that The sputtering time of the magnetron sputtering in step (1) is 10-30 minutes.

7. The method according to claim 1, characterized in that The sputtering power of the magnetron sputtering in step (1) is 50-150W.

8. The method according to claim 1, characterized in that The surface metal thickness of the conductive fabric A in step (1) is 0.1-1 μm.

9. The method according to claim 1, characterized in that: The polymer film described in step (2) is one or more of cellulose, regenerated cellulose, polyamide, polysulfone, polyvinylidene fluoride, polytetrafluoroethylene, polypropylene, and polyester.

10. The method according to claim 1, characterized in that The thickness of the polymer film in step (2) is 0.05 mm to 2 mm.

11. The method according to claim 1, characterized in that: The target material for vacuum coating in step (2) is one of metals selected from nickel, titanium, zinc, chromium, magnesium, niobium, tin, aluminum, indium, iron, zirconium, copper, germanium, silver, cobalt, gold, and tungsten, or alloys thereof.

12. The method according to claim 1, characterized in that: The vacuum coating time in step (2) is 5-20 minutes.

13. The method according to claim 1, characterized in that The power of the vacuum coating in step (2) is 100-300W.

14. The method according to claim 1, characterized in that The surface metal thickness of the conductive film B in step (2) is 0.1-1 μm.

15. The method according to claim 1, characterized in that The carbon-based absorbing material in step (3) is one or more of carbon nanotubes and their derivatives, graphene and their derivatives, carbon black and their derivatives, MXene and their derivatives, carbon quantum dots and their derivatives, and fullerene and their derivatives.

16. The method according to claim 1, characterized in that The polymer in step (3) is one or more of polypropylene, polyethylene, polyvinyl chloride, polyester, polyvinylidene fluoride, polytetrachloroethylene, and polyethylene-vinyl acetate.

17. The method according to claim 1, characterized in that The solvent in step (3) is one or more of ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, N-methylmorpholine oxide, room temperature plasma, formic acid, acetic acid, trifluoroacetic acid, trifluoroethanol, chloroform, dichloromethane, hexafluoroisopropanol, and tetrahydrofuran.

18. The method according to claim 1, characterized in that The mass fraction of the polymer in the solvent in step (3) is 10-30wt.%.

19. The method according to claim 1, characterized in that The concentration of the carbon-based absorbing material in step (3) is 10wt.%-50wt.%.

20. The method according to claim 1, characterized in that The thickness of the absorbing layer in step (3) is 0.1 mm to 2 mm.

21. The method according to any one of claims 1 to 20, characterized in that: The packaging in step (4) is one or more of high temperature pressure packaging, plastic packaging, and plastic shell packaging.

22. A modular full-spectrum electromagnetic shielding flexible composite fabric prepared by the method according to any one of claims 1 to 21.

23. The modular full-spectrum electromagnetic shielding flexible composite fabric according to claim 22, characterized in that: The thickness of the modular full-spectrum electromagnetic shielding flexible composite fabric is 0.1 mm-5 mm.

24. Use of the modular full-spectrum electromagnetic shielding flexible composite fabric according to claim 22 or 23 in the preparation of electronic components.

25. Application of the modular full-spectrum electromagnetic shielding flexible composite fabric according to claim 22 or 23 in the military field.

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