Electromagnetic shielding graphene metal copper mesh and preparation method thereof

Abstract

The application discloses a kind of electromagnetic protection graphene metal copper net and preparation method thereof, specifically related to electromagnetic field shielding technical field, the graphene metal copper net includes graphene metal copper net body, graphene metal copper net body is the diamond metal net structure formed by punching processing of graphene copper foil to punching machine, graphene copper foil is the graphene / metal copper composite material obtained after copper base material and graphene material are compounded, and it is prepared into metal foil structure after being laminated and being rolled by laminated rolling device.The graphene metal copper net provided by the application not only satisfies lightning protection ability and electromagnetic shielding performance integrated protection demand, but also realizes the lightweight of conventional lightning protection copper net under the premise of keeping the lightning protection effect unchanged, the preparation method of the application combines CVD graphene growth technology, laminated rolling composite technology and extension punching net-making technology, with the advantages of automation, high degree of integration, high production efficiency and stability, and low product cost.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic field shielding technology, and more specifically, to an electromagnetic protection graphene-copper mesh and its preparation method. Background Technology

[0002] The use of carbon fiber composite materials is a primary design method for reducing the structural weight of modern aircraft. However, due to the low thermal conductivity and high impedance of these composite materials, they are highly susceptible to damage from lightning strikes, directly impacting flight safety. Therefore, lightning protection design is required to meet airworthiness standards. Common lightning protection technologies for composite materials include flame-sprayed aluminum and lightning-resistant copper mesh. However, the high temperatures used in flame-sprayed aluminum can ablate the composite material, leading to its susceptibility to corrosion and significant weight gain. Consequently, flame-sprayed aluminum lightning protection has been gradually phased out. Currently, many aircraft both domestically and internationally utilize conventional lightning-resistant copper mesh to meet the lightning protection requirements of composite materials.

[0003] Conventional lightning protection metal mesh (copper and aluminum mesh) is made by stretching and punching metal foil of a certain thickness. To a certain extent, it only provides single-function lightning protection, and its weight per unit area (area density) is determined by the metal mesh itself and its mesh shape. However, while conventional copper lightning protection mesh can solve the lightning protection problem, besides being heavy, it also suffers from poor electromagnetic shielding effectiveness. As the external electromagnetic environment of aircraft becomes increasingly complex and diverse, the electromagnetic safety and adaptability of aircraft are becoming increasingly prominent, placing enormous protection pressure and design challenges on airborne equipment. Summary of the Invention

[0004] This invention provides an electromagnetic shielding graphene-copper mesh and its preparation method. The problem it aims to solve is that while conventional lightning protection copper meshes can address lightning protection issues, they suffer from drawbacks such as heavy weight and poor electromagnetic shielding effectiveness. As the external electromagnetic environment of aircraft becomes increasingly complex and diverse, the electromagnetic safety and adaptability of aircraft are becoming more prominent, placing enormous protection pressure and design challenges on airborne equipment.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an electromagnetic protection graphene-copper mesh, comprising a graphene-copper mesh body, wherein the graphene-copper mesh body is a rhombic metal mesh structure formed by punching graphene copper foil through a punching and cutting machine, and the graphene copper foil is a graphene / copper composite material obtained by combining copper substrate material and graphene material, and is a metal foil structure prepared by lamination and rolling composite by a lamination and rolling device.

[0006] A method for preparing an electromagnetically shielding graphene-copper mesh includes the following steps:

[0007] Step 1: Place the graphene copper foil into the corresponding automatic unwinding system and use the automatic unwinding system to control the unwinding of the graphene copper foil.

[0008] Step 2: Input the graphene copper foil into the punching and cutting machine. Through the punching and cutting action of the upper and lower dies, the graphene copper foil is punched to form a graphene metal copper mesh. The punched graphene metal copper mesh is then stretched by the traction and stretching system.

[0009] Step 3: Input the graphene metal copper mesh body output from the traction and tensioning system into the flattening system to flatten the graphene metal copper mesh body.

[0010] Step 4: Input the graphene copper mesh output from the flattening system into the graphene copper mesh winding device, which then winds it into a roll.

[0011] In a preferred embodiment, the graphene copper foil is a layered distributed graphene copper foil, the copper substrate material is a copper foil substrate, and the layered distributed graphene copper foil is prepared by the following steps:

[0012] S1. Place the copper foil substrate into the corresponding automatic unwinding system and use the automatic unwinding system to control the unwinding of the copper foil substrate;

[0013] S2. Input the copper foil substrate into the pretreatment device and heat-treat the copper foil substrate through the pretreatment device.

[0014] S3. Input the copper foil substrate output from the pretreatment device into the CVD graphene growth device. The CVD graphene growth device grows graphene material on the copper foil substrate based on CVD graphene growth technology.

[0015] S4. The copper foil substrate output from the CVD graphene growth device is input into the lamination rolling device, and the copper foil substrate is laminated and rolled by the lamination rolling device to form a layered distributed graphene copper foil.

[0016] In a preferred embodiment, the graphene copper foil is a dispersed graphene copper foil, and the copper substrate material is a copper powder substrate. The dispersed graphene copper foil is prepared by the following steps:

[0017] L1. Place the copper powder substrate in a container and send it into the CVD graphene growth device to grow graphene material on the copper powder substrate using CVD graphene growth technology.

[0018] L2. The copper powder substrate with graphene material grown on it output from the CVD graphene growth device is input into the hot pressing molding device, heated and pressed, and extruded and molded. The molded blank is then sintered at high temperature to form a graphene copper blank.

[0019] L3. The graphene copper billet is fed into the lamination rolling device, and the graphene copper billet is laminated and rolled by the lamination rolling device to form a dispersed graphene copper foil.

[0020] In a preferred embodiment, the container used to store the copper powder substrate in step L1 is a shaped carrier container made of a material that inhibits graphene nucleation.

[0021] In a preferred embodiment, the lamination rolling apparatus performs lamination rolling operations under a vacuum or protective gas atmosphere, wherein the protective gas includes N2, Ar, or a mixture of N2 and Ar.

[0022] In a preferred embodiment, the punching and screen making machine includes an upper die, a lower die, and a copper foil moving drive system. Multiple sets of V-shaped cutters are fixedly installed on the upper die, and the V-shaped cutters form a shearing engagement with the lower die. The copper foil moving drive system is used to control the movement of the graphene copper foil, and a counter-support component is provided on the outer side of the lower die at the position corresponding to the position of the V-shaped cutters.

[0023] In a preferred embodiment, the anti-support assembly includes multiple sets of floating frames, which are slidably disposed on the lower die and distributed along the length of the lower die. The bottom of the floating frame is provided with an elastic support member, which provides an upward elastic force to the floating frame. The top of the floating frame is provided with a support head, which is used to contact the V-shaped strip and provide upward support to the V-shaped strip under the elastic support of the elastic support member.

[0024] In a preferred embodiment, an oil reservoir is fixedly installed on the outer side of the lower die, a piston column is fixedly connected to the bottom of the floating frame, a piston chamber is provided inside the oil reservoir, the piston column is slidably installed in the piston chamber, an elastic support is installed at the bottom of the piston column, and a bearing head is rotatably installed on the top of the floating frame, with a flat surface on the top of the bearing head.

[0025] In a preferred embodiment, the oil storage box has an oil storage chamber inside, which is connected to an oil supply pipe. Each piston chamber is connected to the oil storage chamber. The floating frame and piston column have vertically penetrating oil supply channels inside. The top of the floating frame, which mates with the bearing head, has an arc-shaped groove. The bearing head has an oil outlet hole extending to the flat part inside, and the bottom of the oil outlet hole is adapted to the arc-shaped groove. One-way valve structures are provided in the oil supply channels and the oil supply pipe.

[0026] The beneficial effects of this invention are as follows: This invention provides an electromagnetically shielded graphene-copper mesh and its preparation method, which not only meets the integrated protection requirements of lightning protection capability and electromagnetic shielding performance, but also achieves a lightweighting of conventional lightning protection copper mesh (weight reduction of at least 8%) while maintaining the same lightning protection effect. The preparation method of this invention combines CVD graphene growth technology, multilayer rolling composite technology, and extended punching mesh making technology, which has the advantages of high automation and integration, high production efficiency and stability, and greatly reduces product costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the graphene-copper mesh structure of the present invention.

[0028] Figure 2 This is a process diagram for preparing the graphene-copper mesh of the present invention.

[0029] Figure 3 This is a flowchart of the preparation method of the graphene metal copper mesh of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of the layered distributed graphene copper foil of the present invention.

[0031] Figure 5 This is a schematic diagram of the structure of the distributed graphene copper foil of the present invention.

[0032] Figure 6 This is a process diagram for preparing the layered distributed graphene copper foil of the present invention.

[0033] Figure 7 This is a process diagram for preparing the dispersed graphene copper foil of the present invention.

[0034] Figure 8 This is a schematic diagram of the main structure of the punching and screen making machine of the present invention.

[0035] Figure 9 This is a schematic diagram of the working state of the punching and screen making machine of the present invention.

[0036] Figure 10 For the present invention Figure 8 Enlarged view of the structure of part A.

[0037] Figure 11 This is a diagram showing the state of the punching and screen-making machine of the present invention during the punching and screen-making process.

[0038] Figure 12 For the present invention Figure 11 Enlarged view of the structure of part B.

[0039] Figure 13 This is a diagram showing the state of the reverse support component providing reverse support to the V-shaped strip cut out by the V-shaped cutter of the present invention when it is punching graphene copper foil.

[0040] Figure 14 This is a schematic diagram of the improved anti-support component of the present invention.

[0041] Figure 15 This is a diagram showing the adaptation state of the improved anti-bracing component and the V-shaped strip of the present invention.

[0042] Figure 16 This is a schematic diagram of the internal structure of the piston column in the improved anti-support assembly of the present invention.

[0043] The attached figures are labeled as follows: 1. Graphene-copper mesh; 101. Copper substrate material; 102. Graphene material; 1011. Copper foil substrate; 1012. Copper powder substrate; 11. Graphene copper foil; 111. Layered distributed graphene copper foil; 112. Dispersed distributed graphene copper foil; 1121. Graphene copper billet; 12. V-shaped strip; 2. Punching and cutting machine; 21. Traction and stretching system; 22. Upper die; 23. Lower die; 24. V-shaped cutter; 25. Copper foil transfer. 1. Drive system; 2. Flattening system; 3. Graphene metal copper mesh winding equipment; 4. CVD graphene growth device; 5. Pretreatment device; 6. Lamination rolling device; 7. Hot pressing forming device; 8. Counter-support assembly; 8. Floating frame; 8. Floating column; 8. Floating cylinder; 8. Floating oil supply channel; 8. Floating head; 8. Floating plate; 8. Floating oil outlet; 8. Floating plate; 8. Floating oil outlet; 8. Floating plate; 8. Floating oil outlet; 8. Floating plate; 8. Floating oil supply pipe; 8. Floating oil storage box; 8. Floating cylinder; 8. Floating oil supply pipe; 8. Floating oil supply pipe; 8. Floating oil supply device ... Detailed Implementation

[0044] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0045] Refer to the instruction manual appendix Figures 1 to 5 An electromagnetic shielding graphene-copper mesh includes a graphene-copper mesh body 1, which is a rhomboid metal shielding mesh structure formed by punching graphene copper foil 11 through a punching and cutting machine 2. The graphene copper foil 11 includes a copper substrate material 101, in which graphene material 102 is disposed. The graphene copper foil 11 is a metal foil structure of the required thickness prepared by stacking and rolling a graphene / copper composite material obtained by stacking copper substrate material 101 and graphene material 102 through a stacking and rolling device 6.

[0046] Based on the above-mentioned graphene-copper mesh 1, refer to the appendix of the instruction manual. Figures 2 to 3 The present invention also provides a method for preparing an electromagnetically shielded graphene-copper mesh, comprising the following steps:

[0047] Step 1: Place the graphene copper foil 11 into the corresponding automatic unwinding system and use the automatic unwinding system to control the unwinding of the graphene copper foil 11.

[0048] Step 2: After the graphene copper foil 11 is fed through the feeding pressure roller device into the punching and screen making machine 2, the feeding pressure roller device flattens and guides the graphene copper foil 11. Through the punching and cutting cooperation of the upper die 22 and the lower die 23, the graphene copper foil 11 is punched to form a graphene metal copper mesh body 1. The traction and stretching system 21 of the punching and screen making machine 2 stretches the punched graphene metal copper mesh body 1. Then, the traction and stretching system 21 outputs the unflattened graphene metal copper mesh body 1.

[0049] Step 3: The unflattened graphene metal copper mesh 1 output from the traction and stretching system 21 is guided by the corresponding guide rollers and input into the flattening system 3. It passes through the gap between the pressure rollers in the flattening system 3. The gap value of the pressure rollers is adjusted by setting the system parameters of the flattening system 3. After being processed by the flattening system 3, the unflattened graphene metal copper mesh 1 is formed into a graphene metal copper mesh 1 with a flat surface and neat edges and is then output.

[0050] Step 4: Input the flattened graphene metal copper mesh body 1 output from the flattening system 3 into the graphene metal copper mesh winding device 4, which will then wind it into a roll. During the winding process, the winding uniformity needs to be adjusted at any time to ensure that the edges of the rolled graphene metal copper mesh body 1 are flat.

[0051] In this invention, the graphene copper foil 11 is mainly a metal foil structure of the required thickness prepared by laminating and rolling a graphene / copper composite material obtained by combining a copper substrate material 101 and a graphene material 102 using a lamination and rolling device 6. (Refer to the appendix of the specification.) Figure 4 and Figure 5 The graphene copper foil 11 used in this invention includes two types: layered distributed graphene copper foil 111 and dispersed distributed graphene copper foil 112. In layered distributed graphene copper foil 111, graphene material 102 is layered and compositely formed within a copper substrate material 101. In dispersed distributed graphene copper foil 112, graphene material 102 is dispersed and compositely formed within the copper substrate material 101. Therefore, there are two actual methods for preparing the graphene copper foil 11. Method one of preparing the graphene copper foil 11 includes the following steps, as described in the appendix to the specification. Figure 4 and Figure 6 :

[0052] S1. Place the copper foil substrate 1011 into the corresponding automatic unwinding system and use the automatic unwinding system to control the unwinding of the copper foil substrate 1011.

[0053] S2. The copper foil substrate 1011 is fed into the pretreatment device 51 and the copper foil substrate 1011 is heat-treated by the pretreatment device 51.

[0054] S3. The copper foil substrate 1011 output from the pretreatment device 51 is input into the CVD graphene growth device 5. The CVD graphene growth device 5 is based on CVD graphene growth technology and uniformly grows single or multiple (less than 10 layers) graphene material 102 on the copper foil substrate 1011 (the presence and number of graphene layers can be determined by Raman spectroscopy or other methods).

[0055] S4. The copper foil substrate 1011 with graphene material 102 grown on it output from the CVD graphene growth device 5 is guided by the corresponding guide rollers and then input into the lamination rolling device 6. The lamination rolling device 6 lamination rolling composites one or more copper foil substrates 1011 with graphene material 102 grown on them to form a layered graphene copper foil 111 that meets the thickness requirements.

[0056] S5. The layered graphene copper foil 111 output from the lamination rolling device 6 is automatically wound up by the corresponding automatic winding system.

[0057] In the above scheme, the copper foil substrate 1011 can be set as one or more, and after being laminated by the lamination rolling device 6, a layered distributed graphene copper foil 111 with a single layer or multiple layers is formed. In order to improve the actual performance of the graphene metal copper mesh 1, the copper foil substrate 1011 is preferably two or more.

[0058] Method 2 for preparing graphene copper foil 11 includes the following steps, as detailed in the appendix to the instruction manual. Figure 5 and Figure 7 :

[0059] L1. Place the copper powder substrate 1012 in a specific container, such as a shaped support container made of materials with extremely low catalytic activity to carbon sources or with the ability to inhibit graphene nucleation, such as quartz (SiO2) or alumina (Al2O3), and send it into the CVD graphene growth device 5. Use CVD graphene growth technology to grow graphene material 102 on the copper powder substrate 1012.

[0060] L2. The copper powder substrate 1012 with graphene material 102 grown on it output from the CVD graphene growth device 5 is input into the hot pressing forming device 7. After heating and pressing, the substrate is extruded and formed. The formed blank is then sintered at high temperature (refer to metal powder forming technology) to form a graphene copper blank 1121.

[0061] L3. Input the graphene copper billet 1121 into the lamination rolling device 6, and lamination rolling the graphene copper billet 1121 into a dispersed graphene copper foil 112 that meets the thickness requirements through the lamination rolling device 6.

[0062] L4. The distributed graphene copper foil 112 output from the lamination rolling device 6 is automatically wound up by the corresponding automatic winding system.

[0063] In the above schemes, whether it is preparation method one or preparation method two, the graphene / copper composite material lamination and rolling process should be carried out in a vacuum or protective gas atmosphere, wherein the protective gas includes N2, Ar or a mixture of N2 and Ar, mainly to prevent graphene or copper from being oxidized in the air.

[0064] It should be noted that the punching and cutting mesh making machine 2, the flattening system 3, the CVD graphene growth device 5, the lamination rolling device 6, and the hot pressing forming device 7 used in this invention are all commonly used basic equipment in metal plate, metal mesh, and graphene growth technology. As for the unwinding and winding equipment, which are commonly used in the production process of the above metal strip and mesh, their specific principles and structures will not be explained in detail in this embodiment.

[0065] Among them, the punching and cutting mesh making machine 2 adopts the existing steel plate mesh making machine, also known as a steel plate mesh punching and shearing machine, diamond mesh machine, stretched mesh machine, round hole mesh machine, and irregular shaped mesh punching and perforating machine. It mainly punches and shears metal plates and then stretches them into diamond-shaped mesh metal mesh. During the punching and cutting process, the metal plate enters the punching and cutting mesh making machine 2 through an automatic feeding system and is corrected by a leveling device to eliminate the bending or deformation that may occur in the plate during transportation and storage, ensuring the accuracy and flatness of subsequent processing. After leveling, the metal plate enters the cutting area, where a set of special cutters (i.e., upper die 22 and V-shaped cutter 24) cuts the plate to form a specific V-shaped cut. By continuously changing the position of the V-shaped cutter 24, the cut position is changed, thereby forming a mesh structure. Then, the traction stretching system 21 pulls and stretches the metal plate (through the action of a series of rollers or molds, stretching along the cut direction, causing the metal plate to undergo plastic deformation and expand into a metal mesh with regular grids).

[0066] For example, refer to the instruction manual appendix Figure 8 and Figure 9The punching and screen making machine 2 includes an upper die 22, a lower die 23, and a copper foil moving drive system 25. Multiple sets of V-shaped cutters 24 are fixedly installed on the upper die 22. The V-shaped cutters 24 and the lower die 23 form a shearing engagement. The graphene copper foil 11 passes through the copper foil moving drive system 25. The copper foil moving drive system 25 is used to control the left and right movement of the graphene copper foil 11 to change the cutting position (the cutting position can also be changed by altering the position of the V-shaped cutters 24). During shearing, the graphene copper foil 11 passes through the area between the upper die 22 and the lower die 23. By controlling the upper die 22 to move closer to the lower die 23, the material extending from the lower die 23 area of ​​the graphene copper foil 11 is directed towards... The process involves punching and forming multiple V-shaped cuts, with V-shaped strips 12 formed at the cuts. The material is not cut off, and the upper part of the V-shaped strips 12 remains connected to the graphene copper foil 11. Since multiple V-shaped cutters 24 are continuously set, multiple V-shaped strips 12 are formed in a single punching, creating a wavy structure. During the second punching, the graphene copper foil 11 is driven to move relative to the V-shaped cutter 24 by half a cut distance, and punching is performed again to form new V-shaped strips 12 that are offset from the previous set of V-shaped strips 12, thereby forming a diamond-shaped mesh. This process is repeated to form a complete graphene metal copper mesh 1 by punching and making the mesh, thus completing the punching and making process.

[0067] The key to punching and screen making lies in the precise control of the cutting and stretching process to ensure the consistent quality of the produced graphene copper mesh 1, including the size, shape, and overall flatness of the mesh. For example, the length of a single long diagonal of the graphene copper mesh 1 is the long intercept, the length of a single short diagonal of the graphene copper mesh 1 is the short intercept, the distance between the upper and lower surfaces of the graphene copper mesh 1 is the thickness, and the width used to make a wire is the wire width. The punching and screen making machine 2 is equipped with a mesh shape parameter design and control system. This mesh shape parameter design and control system can be manually operated to set the mesh shape parameters (i.e., the above parameters) of the graphene copper mesh 1. Based on the mesh shape parameter design and control system, the punching and screen making machine 2 is controlled. The punching of the graphene copper foil 11 is completed by the cooperation of the V-shaped cutter 24 on the upper die 22 and the lower die 23.

[0068] Based on the above steps, electromagnetic protection graphene-copper mesh suitable for different lightning zones can be prepared. For example, depending on the requirements, the graphene-copper mesh body 1 can be processed to have an areal density of 67 g / m². 2 Electromagnetic shielding mesh can also be processed to have a surface density of 142 g / m³. 2 The electromagnetic protection graphene-copper mesh prepared by this invention achieves a weight reduction of more than 5% while maintaining the same lightning protection capability as conventional lightning protection copper mesh. Specifically, its areal density is 73 g / m². 2The graphene-copper mesh 1 can be reduced to 66g / m² 2 Weight reduction of 9.5%; surface density of 142 g / m³ 2 The graphene-copper mesh 1 can be reduced in weight to 130g / m². 2 Weight loss of 8.5%.

[0069] Meanwhile, the graphene-copper mesh 1 prepared by this invention can also effectively improve shielding performance, for example, with an areal density of 120 g / m². 2 The graphene-copper mesh body 1 (integrated graphene-copper mesh for lightning protection and electromagnetic shielding) meets the requirements for lightning protection while achieving a shielding performance of 40dB to 69dB in the range of 1GHz to 40GHz, thus improving the electromagnetic shielding performance of the aircraft structure.

[0070] In the above embodiments, the preparation of the graphene-copper mesh 1 mainly relies on the existing punching and cutting machine 2. Therefore, the detailed structure and equipment of the punching and cutting machine 2 will not be explained in detail in this embodiment. However, the existing punching and cutting machine 2 is mainly for steel plate mesh making. The steel plate itself is a single material and has relatively good toughness. However, in this embodiment, the main material being processed is graphene copper foil 11. When a copper substrate material 101 is provided, graphene material 102 is grown inside. Therefore, the ductility of the material itself is relatively poor compared to the steel plate. When the mesh size is relatively small, when the V-shaped strip 12 is punched from a straight material to a V-shaped material in a single cut, the deformation and extension length of the structure on both sides are relatively small. Therefore, it has no impact on the actual production quality of the graphene-copper mesh 1. However, for a For large-aperture graphene copper foil 11, during the punching process of the V-shaped cutter 24, the deformation and extension of the structures on both sides of the V-shaped strip 12 are relatively large. In particular, when the structures on both sides are only subjected to the pressure of the upper V-shaped cutter 24, while the bottom is in a suspended state, stress concentration is very likely to occur. This affects the bonding between the graphene material 102 and the copper substrate material 101 in the graphene metal copper mesh 1. Especially for the graphene metal copper mesh 1 made of multilayer layered graphene copper foil 111, the uneven stress can easily affect the bonding strength of the materials. In severe cases, it can even lead to the separation of the graphene material 102 and subsequent cracking of the material. To improve the preparation quality of the graphene metal copper mesh 1, this embodiment also provides the following technical solutions, which are detailed in the appendix to the specification. Figures 8 to 13A counter-support component 8 is provided at the position below the cut on the lower die 23, that is, a counter-support component 8 is provided on the outer side of the lower die 23 at the position corresponding to the V-shaped cutter 24. The counter-support component 8 includes multiple floating frames 81, which are slidably mounted on the lower die 23 and distributed along the length of the lower die 23. An elastic support member 83 is provided at the bottom of the floating frame 81 to provide an upward elastic force to the floating frame 81. A support head 82 is provided at the top of the floating frame 81. 2 is used to contact the V-shaped strip 12 and, under the elastic support of the elastic support member 83, provide upward support to the V-shaped strip 12. Thus, when the V-shaped cutter 24 punches the graphene copper foil 11, it provides reverse support to the gradually formed V-shaped strip 12, forming an upward extrusion force on the V-shaped strip 12. This reduces the problem of uneven force during the forming of the V-shaped strip 12, reduces the phenomenon of material delamination and cracking caused by the separation of graphene material 102, and further improves the preparation quality of the graphene metal copper mesh 1.

[0071] It should be noted that after one punching is completed, the V-shaped cutter 24 rises with the upper die 22, and the formed graphene metal copper mesh 1 is stretched and pulled a certain distance by the traction stretching system 21. Therefore, the newly formed V-shaped strip 12 will detach outward from the support head 82, and each floating frame 81 can automatically reset to cooperate with the next punching operation.

[0072] In the above embodiment, the bearing head 82 can be a cylindrical structure disposed on the floating frame 81. The circumferential side of the bearing head 82 is adapted to the V-shaped strip 12, thereby reducing the friction between the V-shaped strip 12 and the floating frame 81 during forming. At the same time, a cavity can be provided inside the lower die 23, and the floating frame 81 can be slidably installed in the cavity inside the lower die 23. The elastic support member 83 can be a spring structure installed at the bottom of the floating frame 81, thereby forming a low-cost counter-support assembly 8.

[0073] It should be noted that, since the floating frame 81 is located inside the lower die 23, and the support head 82 needs to contact the V-shaped strip 12 as soon as it begins to form, the support head 82 needs to be as close as possible to the top cut of the lower die 23 when the elastic support member 83 extends. Therefore, to ensure the structural integrity at the cut of the lower die 23, this embodiment improves the aforementioned counter-support component 8. For details, please refer to the appendix of the instruction manual. Figure 14 and Figure 15An oil reservoir 84 is fixedly installed on the outer side of the lower die 23. A piston column 811 is fixedly connected to the bottom of the floating frame 81. A piston chamber 841 is provided inside the oil reservoir 84. The piston column 811 is slidably installed in the piston chamber 841. An elastic support 83 is installed at the bottom of the piston column 811, so that the anti-support assembly 8 can be slidably set on the outer side of the lower die 23. At the same time, the lower edge of the piston column 811 can free up the space above, so as not to obstruct part of the formed graphene metal copper mesh 1.

[0074] Furthermore, if the aforementioned support head 82 adopts a simple cylindrical structure, then when the support head 82 contacts the V-shaped bar portion 12, the contact is mainly a line contact, resulting in poor support effect. Therefore, the support head 82 can be rotatably mounted on the top of the floating frame 81, and the support head 82, based on the cylindrical structure, has a flat portion 821 on its top. Thus, under the rotatable condition of the support head 82, when providing reverse support to the V-shaped bar portion 12, the flat portion 821 can contact the V-shaped bar portion 12 as much as possible, thereby providing more effective contact.

[0075] Furthermore, in continuous processing, to prevent wear on materials such as graphene copper foil 11, lubricating oil is applied to the corresponding parts. However, due to the numerous structures of the counter-support assembly 8 and the need for continuous coordination with the V-shaped cutter 24, directly applying lubricating oil is not suitable. Therefore, this embodiment also provides the following technical solution, as detailed in the appendix to the specification. Figures 14 to 16 The oil reservoir 84 has an internal oil storage chamber connected to an oil supply pipe 842. Each piston chamber 841 is connected to the oil storage chamber. The floating frame 81 and piston column 811 have internally connected vertically through oil supply channels 812. The top of the floating frame 81, where it mates with the bearing head 82, has an arc-shaped groove. The bearing head 82 has an oil outlet 822 extending to the flat portion 821, with the bottom of the oil outlet 822 fitting the arc-shaped groove. One-way valve structures 85 are installed in both the oil supply channel 812 and the oil supply pipe 842. Thus, by means of the lifting and lowering of the floating frame 81, a plunger pump system is formed. When the floating frame 81 is pressed down, the one-way valve structure 85 in the oil supply pipe 842 is closed, and the one-way valve structure 85 in the oil supply channel 812 is open. The lubricating oil inside the oil storage box 84 flows to the surface of the flat part 821 through the oil supply channel 812 and the oil outlet hole 822, forming a lubricating effect on the V-shaped strip part 12. When the floating frame 81 is raised, the one-way valve structure 85 in the oil supply channel 812 is closed, and the one-way valve structure 85 in the oil supply pipe 842 is open. Thus, lubricating oil can be drawn from the external oil storage device, forming a self-supply of lubricating oil, further ensuring the preparation quality of the graphene metal copper mesh 1.

[0076] It should be noted that, since the piston rod 811 is relatively small, the one-way valve structure 85 in the oil supply channel 812 can be set with a simple ball bearing and corresponding hole structure as the one-way valve structure 85. The existing one-way valve structure can be used directly in the oil supply pipe 842. The bearing head 82 can be rotatably mounted on the rotating shaft at the top of the floating frame 81. The oil outlet 822 can pass through the aforementioned rotating shaft, and thus can also simultaneously lubricate the rotation of the bearing head 82.

[0077] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. 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 modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing an electromagnetically shielded graphene-copper mesh, the electromagnetically shielded graphene-copper mesh comprising a graphene-copper mesh body (1), wherein the graphene-copper mesh body (1) is a rhombic metal mesh structure formed by punching graphene copper foil (11) through a punching and mesh-making machine (2), wherein the graphene copper foil (11) is a graphene / copper composite material obtained by combining copper substrate material (101) and graphene material (102), and is a metal foil structure prepared by lamination and rolling composite by a lamination and rolling device (6), characterized in that, The preparation method includes the following steps: Step 1: Place the graphene copper foil (11) into the corresponding automatic unwinding system and use the automatic unwinding system to control the unwinding of the graphene copper foil (11); Step 2: Input the graphene copper foil (11) into the punching and cutting machine (2). Through the punching and cutting cooperation of the upper die (22) and the lower die (23), the graphene copper foil (11) is punched to form a graphene metal copper mesh (1). The graphene metal copper mesh (1) after punching is stretched by the traction stretching system (21). Step 3: Input the graphene metal copper mesh (1) output by the traction and stretching system (21) into the flattening system (3) to flatten the graphene metal copper mesh (1); Step 4: Input the graphene metal copper mesh body (1) output by the flattening system (3) into the graphene metal copper mesh winding device (4), and the graphene metal copper mesh winding device (4) winds it into a roll. The punching and cutting machine (2) includes an upper die (22), a lower die (23), and a copper foil moving drive system (25). Multiple sets of V-shaped cutters (24) are fixedly installed on the upper die (22). The V-shaped cutters (24) and the lower die (23) form a shearing engagement. The copper foil moving drive system (25) is used to control the movement of the graphene copper foil (11). During shearing, the graphene copper foil (11) passes through the area between the upper die (22) and the lower die (23). By controlling the upper die (22) to move closer to the lower die (23), the material of the graphene copper foil (11) extending out of the area of ​​the lower die (23) is punched downward and multiple V-shaped cuts are formed. A V-shaped strip (12) is formed at the cut. A counter-support component (8) is provided on the outer side of the lower die (23) at the position corresponding to the V-shaped cutter (24). The anti-support assembly (8) includes multiple sets of floating frames (81), which are slidably disposed on the lower die (23) and distributed along the length of the lower die (23). The bottom of the floating frame (81) is provided with an elastic support member (83), which provides an upward elastic force to the floating frame (81). The top of the floating frame (81) is provided with a support head (82), which is used to contact the V-shaped strip (12) and provide upward support to the V-shaped strip (12) under the elastic support of the elastic support member (83).

2. The method for preparing an electromagnetically shielded graphene-copper mesh according to claim 1, characterized in that: The graphene copper foil (11) is a layered distributed graphene copper foil (111), and the copper substrate material (101) is a copper foil substrate (1011). The layered distributed graphene copper foil (111) is prepared by the following steps: S1. Place the copper foil substrate (1011) into the corresponding automatic unwinding system and use the automatic unwinding system to control the unwinding of the copper foil substrate (1011); S2. The copper foil substrate (1011) is fed into the pretreatment device (51) and the copper foil substrate (1011) is heat-treated by the pretreatment device (51); S3. The copper foil substrate (1011) output by the pretreatment device (51) is input into the CVD graphene growth device (5), which grows graphene material (102) on the copper foil substrate (1011) based on CVD graphene growth technology. S4. The copper foil substrate (1011) output from the CVD graphene growth device (5) is input into the lamination rolling device (6), and the copper foil substrate (1011) is lamination rolled by the lamination rolling device (6) to form a layered distributed graphene copper foil (111).

3. The method for preparing an electromagnetically shielded graphene-copper mesh according to claim 1, characterized in that: The graphene copper foil (11) is a dispersed graphene copper foil (112), and the copper substrate material (101) is a copper powder substrate (1012). The dispersed graphene copper foil (112) is prepared by the following steps: L1. Place the copper powder substrate (1012) in a container and send it into the CVD graphene growth device (5) to grow graphene material (102) on the copper powder substrate (1012) using CVD graphene growth technology. L2. The copper powder substrate (1012) with graphene material (102) output from the CVD graphene growth device (5) is input into the hot pressing molding device (7), heated and pressed, extruded and molded, and then the molded blank is sintered at high temperature to form a graphene copper blank (1121). L3. Input the graphene copper billet (1121) into the lamination rolling device (6) and lamination rolling the graphene copper billet (1121) into a dispersed graphene copper foil (112) by the lamination rolling device (6).

4. The method for preparing an electromagnetically shielded graphene-copper mesh according to claim 3, characterized in that: The container used to store the copper powder substrate (1012) in step L1 is a shaped carrier container made of a material that has the ability to suppress graphene nucleation.

5. A method for preparing an electromagnetically shielded graphene-copper mesh according to claim 2 or 4, characterized in that: The stacking rolling apparatus (6) performs stacking rolling operations in a vacuum or protective gas atmosphere, wherein the protective gas includes N2, Ar or a mixture of N2 and Ar.

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