Preparation and shielding application method of environment-friendly graphite glue for security door

Abstract

The invention discloses a preparation and shielding application method of environment-friendly graphite glue for a security check door, and relates to the technical field of security check equipment.The preparation method comprises the following specific steps that raw materials are prepared, specifically, 10-30 parts of high-purity natural graphite powder, 20-60 parts of an environment-friendly glue matrix, 30-60 parts of a diluent and 0.3-5 parts of an auxiliary additive are prepared for standby application, the high-purity natural graphite powder, the environment-friendly glue matrix and the diluent are used as solvents, so that the use of organic solvents in traditional graphite paint is avoided, the emission of volatile organic compounds is reduced, the environment-friendly performance of the product is remarkably improved, and the requirements of modern industry for green and sustainable development are met; and through advanced process treatments such as microwave pretreatment, hypergravity field intensified mixing and photo-initiation crosslinking, the graphite powder is dispersed in the glue more uniformly and is combined with a glue matrix more firmly, and a formed graphite shielding layer has excellent electromagnetic shielding performance and can effectively resist external interferences such as a human body magnetic field and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of security inspection equipment, and in particular to a method for preparing and shielding environmentally friendly graphite glue for security inspection doors. Background Art

[0002] As an important part of modern security inspection equipment, security doors are widely used in public places such as airports, stations, and conference centers to ensure the safety of people and property. One of the core functions of security doors is to effectively detect and shield electromagnetic signals to prevent external electromagnetic interference from affecting the accuracy of security inspection results. Electromagnetic shielding materials play a vital role in this process. They can not only isolate external electromagnetic fields, but also prevent the leakage of electromagnetic waves inside the security door, thereby ensuring the normal operation of security inspection equipment.

[0003] Traditional electromagnetic shielding technology for security doors mostly uses the method of doping graphite into special paint. However, this method has many disadvantages. First, the organic solvents contained in the paint will evaporate during use, releasing a large amount of volatile organic compounds (VOCs), which not only pollutes the environment, but also seriously endangers the health of operators and surrounding personnel. Secondly, the performance stability of the graphite paint coating is insufficient. After long-term use, the coating is prone to peeling, fading and other problems, which not only affects the appearance of the security door, but more importantly, it destroys the integrity of the electromagnetic shielding, resulting in a decrease in shielding effect and a decrease in the reliability of security inspection. In addition, the fluidity of graphite paint is poor, and it is difficult to ensure the uniformity of the shielding layer during the coating process. The uneven shielding layer will cause inconsistent electromagnetic shielding performance, and it will not be able to effectively resist external interference such as the human body's magnetic field, which will have a negative impact on the detection accuracy of the security door.

[0004] In response to the above problems, it is necessary to optimize the existing preparation and shielding application methods of environmentally friendly graphite glue for security doors. By adopting high-purity natural graphite powder, environmentally friendly glue matrix, diluent and other environmentally friendly materials, and through microwave pretreatment, hypergravity field enhanced mixing and photoinduced crosslinking and other processes, environmentally friendly graphite glue with excellent conductivity and electromagnetic shielding properties is prepared. Therefore, it is of great significance to develop a preparation and shielding application method of environmentally friendly graphite glue for security doors that can comprehensively achieve the above characteristics. Summary of the Invention

[0005] The purpose of the present invention is to make up for the shortcomings of the existing technology and provide a method for preparing and shielding environmentally friendly graphite glue for security doors. It can adopt environmentally friendly materials such as high-purity natural graphite powder, environmentally friendly glue matrix, diluent, etc., and prepare environmentally friendly graphite glue with excellent conductivity and electromagnetic shielding performance through advanced processes such as microwave pretreatment, hypergravity field enhanced mixing and photoinduced crosslinking. Compared with traditional graphite paint, the environmentally friendly graphite glue prepared by the present invention not only has superior environmental performance and no volatile organic compound emissions, but also has stable and reliable performance and is not easy to fall off after long-term use. The formed graphite shielding layer has uniform thickness and stable conductive performance, can effectively shield external interference, and ensure that the security door operates accurately and reliably in a complex electromagnetic environment.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: On the one hand, a method for preparing environmentally friendly graphite glue for security doors, the method comprising the following specific steps:

[0007] Raw material preparation: prepare 10-30 parts of high-purity natural graphite powder, 20-60 parts of environmentally friendly glue matrix, 30-60 parts of diluent, and 0.3-5 parts of auxiliary additives for standby use, wherein the auxiliary additives include 0.1-1.5 parts of dispersant, 0.1-0.5 parts of defoaming agent, and 0.1-3 parts of thickener;

[0008] Microwave pretreatment of graphite powder: Graphite powder is placed in a microwave field of specific frequency and power for treatment to increase its surface active sites;

[0009] Additive mixing: Add the diluent to the stirred reactor, start the stirring device and set a specific speed, add the dispersant and stir until the dispersant is evenly dispersed in the water, then add the defoamer and stir to eliminate bubbles in the system, and add the thickener and stir to adjust the viscosity of the glue;

[0010] Hypergravity field enhanced mixing: according to the raw material preparation ratio, add pretreated high-purity natural graphite powder into the reactor under stirring. At the same time, place the reactor in a hypergravity rotating bed to make the hypergravity field intensity reach 50-200g, where g is the acceleration of gravity. Continue stirring for 15-30 minutes to ensure that it is fully mixed.

[0011] Addition of glue matrix and light-induced cross-linking: Add environmentally friendly glue matrix to the reactor, adjust the stirring speed, and apply light of a specific wavelength to the reaction system to induce a cross-linking reaction of specific functional groups in the glue matrix to form a three-dimensional network structure, thereby optimizing the electromagnetic shielding performance of the glue and obtaining environmentally friendly graphite glue.

[0012] Furthermore, in the raw material preparation step, high-purity natural graphite powder with a purity of not less than 95% and a particle size range of 10-50 microns is selected, and water-based acrylic resin and water-based polyurethane resin are used as glue matrices, and their solid content ranges from 30% to 50%.

[0013] Furthermore, in the raw material preparation step, the auxiliary additives include a dispersant, a defoamer and a thickener, wherein the dispersant is a polyacrylate ammonium salt dispersant, the defoamer is a polyether defoamer, and the thickener is hydroxyethyl cellulose.

[0014] Furthermore, in the graphite powder microwave pretreatment step, the prepared high-purity natural graphite powder is placed in a microwave field with a frequency range of 2-6 GHz and a power range of 300-800 W for 5-20 minutes.

[0015] Furthermore, in the additive mixing step, the diluent is added to the stirred reactor, the stirring speed is set to 200-500 rpm, an appropriate amount of dispersant is added, and the mixture is stirred for 5-15 minutes, after which the defoamer is added and stirred for 3-10 minutes to eliminate bubbles in the system, and the thickener is added and stirred for 5-15 minutes to adjust the viscosity of the glue.

[0016] Furthermore, in the glue matrix addition and light-induced crosslinking step, an environmentally friendly glue matrix is added to the reactor, the stirring speed is adjusted to 400-800 rpm and stirred for 20-40 minutes, and at the same time, light with a wavelength range of 300-400 nm is applied to the reaction system to induce a cross-linking reaction of the functional groups in the glue matrix to form a three-dimensional network structure.

[0017] On the other hand, a method for applying environmentally friendly graphite glue shielding for security doors is provided, the method comprising the following specific steps:

[0018] Pretreatment of security door components: Degrease the security door components with ethanol and polish the degreased component surfaces with sandpaper. Rinse the polished components with clean water and dry them.

[0019] Graphite glue coating: Place the security door panel horizontally and use a spray gun to evenly coat the environmentally friendly graphite glue on the surface of the component;

[0020] Curing and performance realization: The coated parts are transferred to a constant temperature and humidity environment with a temperature of 20-30°C and a relative humidity range of 40%-60%. After 24-72 hours of drying, a stable graphite shielding layer is formed to achieve electromagnetic shielding performance.

[0021] Furthermore, in the security door component pretreatment step, the degreased component surface is polished with 80-200 mesh sandpaper to achieve a surface roughness of Ra1.0-3.0 microns, and the polished component is rinsed with clean water and dried in a dry environment at a temperature of 30-60°C for 1-3 hours.

[0022] Furthermore, in the graphite glue coating step, the environmentally friendly graphite glue is evenly coated on the surface of the component using a spray gun, and the coating thickness is 0.5-2 mm.

[0023] Compared with the existing technology, this method for preparing and shielding environmentally friendly graphite glue for security doors has the following beneficial effects:

[0024] 1. The present invention adopts high-purity natural graphite powder, environmentally friendly glue matrix and diluent as solvents, which not only avoids the use of organic solvents in traditional graphite paint, thereby reducing the emission of volatile organic compounds, but also significantly improves the environmental performance of the product, and meets the requirements of modern industry for green and sustainable development. In addition, after advanced process treatments such as microwave pretreatment, hypergravity field enhanced mixing and photoinduced crosslinking, the dispersion of graphite powder in the glue is more uniform, and the bond with the glue matrix is more firmly. The formed graphite shielding layer has excellent electromagnetic shielding performance, which can effectively resist external interference such as the human body magnetic field, ensuring that the security door can still operate accurately and reliably in a complex electromagnetic environment.

[0025] 2. The present invention adopts the prepared environmentally friendly graphite glue, which makes it easy to achieve uniform coverage during the coating process. At the same time, by precisely controlling the raw material ratio and coating thickness, customized coating can be performed according to different security door components and usage requirements, thereby improving the operability and flexibility of construction. In addition, after optimized preparation process and curing conditions, the formed graphite shielding layer is tightly combined with the security door components, is not easy to fall off during long-term use, and has a uniform and stable thickness, thereby ensuring the overall quality and long-term reliability of the security door.

[0026] Other advantages, objects and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be learned from the practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0028] Figure 1 This is a process diagram of a method for preparing environmentally friendly graphite glue for security doors;

[0029] Figure 2 The present invention is a flow chart of an application method of environmentally friendly graphite glue shielding for security doors. DETAILED DESCRIPTION

[0030] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0031] Comparative Example

[0032] Weigh 25g of high-purity natural graphite powder with a purity of 96% and a particle size of 25 microns. Select water-based polyurethane resin as the environmentally friendly glue matrix, measure 35g, with a solid content of 45%, prepare 35g of diluent, add high-purity natural graphite powder, water-based polyurethane resin and diluent to a stirred reactor, set the stirring speed to 350 rpm, and stir for 35 minutes.

[0033] Use acetone to degrease the security door components, polish them with 150-grit sandpaper, rinse with clean water and dry them at 50°C for 2.5 hours. Place the security door panel horizontally and use a spray gun to evenly apply the mixed glue on the surface of the component with a coating thickness of 1.5 mm. Transfer the coated components to a constant temperature and humidity environment with a temperature of 28°C and a relative humidity of 55% and dry them for 60 hours.

[0034] Using professional electromagnetic shielding effectiveness testing equipment, the test was conducted in the frequency range of 10kHz-1GHz, and the average electromagnetic shielding effectiveness was 25dB. According to the ASTMD3359 standard test, the adhesion level was 3B. In the wear resistance test, under the CS-17 grinding wheel and 500g load, the shielding layer thickness loss reached 25% after 500 turns of wear. Due to the poor overall performance, the coating thickness needs to be increased to ensure a certain shielding effect, resulting in a relatively high overall VOC emission of about 15g / L.

[0035] Example 1

[0036] Weigh 25g of high-purity natural graphite powder with a purity of 96% and a particle size of 25 microns. Select an aqueous polyurethane resin with a solid content of 45% as the glue matrix, measure 35g, prepare 35g of diluent as a solvent, weigh 0.8g of polyacrylate ammonium salt dispersant, and measure 0.3g of polyether defoamer. During the preparation of the glue, bubbles may be generated in the system, and the polyether defoamer can effectively eliminate these bubbles and prevent surface defects from forming due to residual bubbles after coating, affecting the shielding effect. Weigh 1.4g of hydroxyethyl cellulose as a thickener to accurately adjust the viscosity of the glue.

[0037] 25g of high-purity natural graphite powder was placed in a special microwave device, with the frequency set to 3GHz, the power to 600W, and the processing time to 12 minutes. Under the action of the microwave field, the internal lattice structure of the graphite powder was optimized and the surface active sites increased, which will significantly improve its dispersion efficiency and uniformity when mixed with other raw materials in the subsequent process, thereby greatly enhancing the overall electromagnetic shielding performance of the glue.

[0038] Add the prepared 35g diluent to a reactor with a stirring device, start the stirring device, set the speed to 350 rpm, slowly add 0.8g polyacrylate ammonium salt dispersant, and continue stirring for 12 minutes to allow the dispersant to be fully and evenly dispersed in the water. After the dispersant is evenly dispersed, add 0.3g polyether defoamer and continue stirring for 7 minutes. During this process, the polyether defoamer plays a role and effectively eliminates bubbles in the system caused by stirring and other operations. Then add 1.4g hydroxyethyl cellulose and stir for 12 minutes. Accurately adjust the viscosity of the glue to give it ideal coating performance and enable it to evenly cover the surface of the security door components to ensure the quality of the shielding layer.

[0039] The reactor was transferred to a high-gravity rotating bed, and the high-gravity field intensity was adjusted to 120g. High-purity natural graphite powder pretreated by microwaves was added under continuous stirring. The effect of the high-gravity field greatly increased the relative velocity between phases and the phase interface renewal rate. The graphite powder was subjected to strong shear and tensile forces in the solution, thereby being quickly and evenly dispersed in the solution, effectively avoiding local agglomeration, significantly enhancing the binding force between graphite powder and other ingredients, and further improving the comprehensive performance of the glue. The mixing process was stirred for 25 minutes to ensure sufficient mixing.

[0040] After completing the above steps, add 35g of water-based polyurethane resin to the reactor, adjust the stirring speed to 650 rpm, and stir for 35 minutes. At the same time, turn on the lighting equipment with a specific wavelength and apply light with a wavelength of 380nm to the reaction system. The light triggers the specific functional groups in the glue matrix to undergo a cross-linking reaction to form a three-dimensional network structure. This structure not only significantly enhances the cohesion of the glue itself and its binding force with the graphite powder, but also further optimizes the electromagnetic shielding performance of the glue, making it perform better in security door shielding applications. After this step, an environmentally friendly graphite glue with excellent performance is obtained.

[0041] For the metal parts of the security door, use acetone as a degreasing agent, apply an appropriate amount of acetone on the surface of the part, and then wipe it carefully with a clean cloth to ensure that the oil, grease and other organic pollutants on the surface are completely removed, and use 150-grit sandpaper to polish the degreased part surface. During the polishing process, apply force evenly to ensure that the roughness of the entire part surface reaches Ra2.5 microns. Rinse the polished parts thoroughly with clean water to ensure that residual acetone, grinding debris and other impurities are completely removed, and then place the parts in a drying oven set at 50°C and dry them for 2.5 hours to make the surface of the parts completely dry and no water stains remain, ready for coating glue.

[0042] Place the pretreated security door panel horizontally on a clean and flat workbench to ensure that the door panel will not shake during the coating process. At the same time, clean and debug the spray gun. Use the debugged spray gun to evenly coat the prepared environmentally friendly graphite glue on the surface of the pretreated component. During the coating process, maintain an appropriate distance and angle between the spray gun and the door panel, move the spray gun at a constant speed, and strictly control the coating thickness to 1.5 mm to ensure that the graphite shielding layer is uniform and consistent, laying the foundation for stable and efficient electromagnetic shielding performance. Transfer the coated components to a constant temperature and humidity chamber with a set temperature of 28°C and a relative humidity of 55%. Under such stable environmental conditions, after 60 hours of drying, the glue is fully cured to form a stable graphite shielding layer. The shielding layer is tightly bonded to the door panel and is not easy to fall off after long-term use. The thickness is uniform and stable, and it has stable and uniform conductive properties. It can effectively shield external interference such as the human body's magnetic field, ensuring that the security door operates accurately and reliably in a complex electromagnetic environment.

[0043] Using professional electromagnetic shielding effectiveness testing equipment, the test was carried out in the frequency range of 10kHz-1GHz, and the average electromagnetic shielding effectiveness reached 40dB. According to the ASTMD3359 standard, the adhesion level reached 5B. Using the wear resistance test method, a CS-17 grinding wheel was used to perform abrasion tests on parts coated with the shielding layer under a load of 500g. After 1000 turns of abrasion, the thickness change of the shielding layer was measured, and it was found that the thickness loss was less than 10%. The glue was tested using professional volatile organic compound (VOC) detection equipment, which showed that the VOC emission was less than 10g / L.

[0044] Example 2

[0045] Weigh 15g of high-purity natural graphite powder with a purity of 96% and a particle size of 25 microns. Select water-based polyurethane resin as the environmentally friendly glue matrix, measure 35g with a solid content of 45%, prepare 35g of diluent, weigh 0.8g of polyacrylate ammonium salt dispersant, measure 0.3g of polyether defoamer, and weigh 1.4g of hydroxyethyl cellulose.

[0046] High-purity natural graphite powder was placed in a microwave field with a frequency of 3 GHz and a power of 600 W for 12 minutes. The diluent was added to the stirred reactor, the stirring device was started, the stirring speed was set to 350 rpm, and the polyacrylate ammonium salt dispersant was added and stirred for 12 minutes. Then, the polyether defoamer was added and stirred for 7 minutes. Then, hydroxyethyl cellulose was added and stirred for 12 minutes.

[0047] The reactor was placed in a high-gravity rotating bed, and the high-gravity field intensity reached 120g. High-purity natural graphite powder pretreated by microwave was slowly added under stirring and stirred for 25 minutes. Water-based polyurethane resin was added to the reactor, and the stirring speed was adjusted to 650 rpm and stirred for 35 minutes. At the same time, light with a wavelength of 380nm was applied to the reaction system to obtain environmentally friendly graphite glue.

[0048] Use acetone to degrease the security door components, and use 150-grit sandpaper to polish the degreased component surface to achieve a surface roughness of Ra2.5 microns. Rinse the polished components with clean water and dry them at 50°C for 2.5 hours. Place the security door panel horizontally and use a spray gun to evenly apply environmentally friendly graphite glue on the component surface with a coating thickness of 1.5 mm. Transfer the coated components to a constant temperature and humidity environment with a temperature of 28°C and a relative humidity of 55%. After drying for 60 hours, a stable graphite shielding layer is formed.

[0049] Using professional electromagnetic shielding effectiveness testing equipment, the product was tested in the frequency range of 10kHz-1GHz, and the average electromagnetic shielding effectiveness reached 30dB. According to the ASTMD3359 standard test, the adhesion level reached 5B. In the wear resistance test, under the CS-17 grinding wheel and 500g load, the shielding layer thickness loss was less than 10% after 1000 rotations. The volatile organic compound (VOC) emission was tested to be less than 10g / L.

[0050] Example 3

[0051] Weigh 35g of high-purity natural graphite powder with a purity of 96% and a particle size of 25 microns. Select water-based polyurethane resin as the environmentally friendly glue matrix, measure 35g with a solid content of 45%, prepare 35g of diluent, weigh 0.8g of polyacrylate ammonium salt dispersant, measure 0.3g of polyether defoamer, and weigh 1.4g of hydroxyethyl cellulose.

[0052] High-purity natural graphite powder was placed in a microwave field with a frequency of 3 GHz and a power of 600 W for 12 minutes. The diluent was added to the stirred reactor, the stirring device was started, the stirring speed was set to 350 rpm, and the polyacrylate ammonium salt dispersant was added and stirred for 12 minutes. Then, the polyether defoamer was added and stirred for 7 minutes. Then, hydroxyethyl cellulose was added and stirred for 12 minutes.

[0053] The reactor was placed in a high-gravity rotating bed, and the high-gravity field intensity reached 120g. High-purity natural graphite powder pretreated by microwave was slowly added under stirring and stirred for 25 minutes. Water-based polyurethane resin was added to the reactor, and the stirring speed was adjusted to 650 rpm and stirred for 35 minutes. At the same time, light with a wavelength of 380nm was applied to the reaction system to obtain environmentally friendly graphite glue.

[0054] Use acetone to degrease the security door components, and use 150-grit sandpaper to polish the degreased component surface to achieve a surface roughness of Ra2.5 microns. Rinse the polished components with clean water and dry them at 50°C for 2.5 hours. Place the security door panel horizontally and use a spray gun to evenly apply environmentally friendly graphite glue on the component surface with a coating thickness of 1.5 mm. Transfer the coated components to a constant temperature and humidity environment with a temperature of 28°C and a relative humidity of 55%. After drying for 60 hours, a stable graphite shielding layer is formed.

[0055] Using professional electromagnetic shielding effectiveness testing equipment, the test was conducted in the frequency range of 10kHz-1GHz, and the average electromagnetic shielding effectiveness reached 48dB. According to the ASTMD3359 standard test, the adhesion level reached 5B. In the wear resistance test, under the CS-17 grinding wheel and 500g load, the shielding layer thickness loss was less than 10% after 1000 rotations. The volatile organic compound (VOC) emission was tested to be less than 10g / L.

[0056]

[0057] In summary, changes in graphite powder content significantly affect the electromagnetic shielding effectiveness of the glue. An appropriate increase in graphite powder can improve the shielding effect, while a decrease will reduce it. In terms of preparation technology, microwave pretreatment optimizes the lattice structure of graphite powder and enhances its dispersion and bonding ability with other raw materials. Ultra-gravity field-enhanced mixing further ensures uniform dispersion of graphite powder and improves the overall performance of the glue. Photoinduced cross-linking forms a three-dimensional network structure, enhancing the glue's cohesion and electromagnetic shielding performance. By reasonably controlling the raw material ratio and process parameters, the performance of environmentally friendly graphite glue can be effectively improved to meet the strict requirements of security doors in terms of electromagnetic shielding, stability and environmental protection.

[0058] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing environmentally friendly graphite glue for security doors, characterized in that: The method comprises the following specific steps: Raw material preparation: prepare 10-30 parts of high-purity natural graphite powder, 20-60 parts of environmentally friendly glue matrix, 30-60 parts of diluent, and 0.3-5 parts of auxiliary additives for standby use, wherein the auxiliary additives include 0.1-1.5 parts of dispersant, 0.1-0.5 parts of defoaming agent, and 0.1-3 parts of thickener; Microwave pretreatment of graphite powder: Graphite powder is placed in a microwave field of specific frequency and power for treatment to increase its surface active sites; Additive mixing: Add the diluent to the stirred reactor, start the stirring device and set a specific speed, add the dispersant and stir until the dispersant is evenly dispersed in the water, then add the defoamer and stir to eliminate bubbles in the system, and add the thickener and stir to adjust the viscosity of the glue; Hypergravity field enhanced mixing: according to the raw material preparation ratio, add pretreated high-purity natural graphite powder into the reactor under stirring. At the same time, place the reactor in a hypergravity rotating bed to make the hypergravity field intensity reach 50-200g, where g is the acceleration of gravity. Continue stirring for 15-30 minutes to ensure that it is fully mixed. Addition of glue matrix and light-induced cross-linking: Add environmentally friendly glue matrix to the reactor, adjust the stirring speed, and apply light of a specific wavelength to the reaction system to induce a cross-linking reaction of specific functional groups in the glue matrix to form a three-dimensional network structure, thereby optimizing the electromagnetic shielding performance of the glue and obtaining environmentally friendly graphite glue.

2. The method for preparing environmentally friendly graphite glue for security doors according to claim 1, wherein: In the raw material preparation step, high-purity natural graphite powder with a purity of not less than 95% and a particle size range of 10-50 microns is selected, and water-based acrylic resin and water-based polyurethane resin are used as glue matrices, with a solid content range of 30%-50%.

3. The method for preparing environmentally friendly graphite glue for security doors according to claim 1, wherein: In the raw material preparation step, the auxiliary additives include a dispersant, a defoamer and a thickener, wherein the dispersant is a polyacrylate ammonium salt dispersant, the defoamer is a polyether defoamer, and the thickener is hydroxyethyl cellulose.

4. The method for preparing environmentally friendly graphite glue for security doors according to claim 1, characterized in that: In the graphite powder microwave pretreatment step, the prepared high-purity natural graphite powder is placed in a microwave field with a frequency range of 2-6 GHz and a power range of 300-800 W for treatment for 5-20 minutes.

5. The method for preparing environmentally friendly graphite glue for security doors according to claim 1, characterized in that: In the additive mixing step, a diluent is added to a stirred reactor, the stirring speed is set to 200-500 rpm, a dispersant is added, and the mixture is stirred for 5-15 minutes, after which a defoamer is added and stirred for 3-10 minutes to eliminate bubbles in the system, and a thickener is added and stirred for 5-15 minutes to adjust the viscosity of the glue.

6. The method for preparing environmentally friendly graphite glue for security doors according to claim 1, characterized in that: In the glue matrix addition and light-induced crosslinking steps, an environmentally friendly glue matrix is added to a reactor, the stirring speed is adjusted to 400-800 rpm and the mixture is stirred for 20-40 minutes. At the same time, light with a wavelength of 300-400 nm is applied to the reaction system to induce a crosslinking reaction of the functional groups in the glue matrix to form a three-dimensional network structure.

7. A method for shielding security doors with environmentally friendly graphite glue, characterized in that: The method comprises the following specific steps: Pretreatment of security door components: Degrease the security door components with ethanol and polish the degreased component surfaces with sandpaper. Rinse the polished components with clean water and dry them. Graphite glue coating: Place the security door panel horizontally and use a spray gun to evenly coat the environmentally friendly graphite glue on the surface of the component; Curing and performance realization: The coated parts are transferred to a constant temperature and humidity environment with a temperature of 20-30°C and a relative humidity range of 40%-60%. After 24-72 hours of drying, a stable graphite shielding layer is formed to achieve electromagnetic shielding performance.

8. The method for applying environmentally friendly graphite glue shielding for security doors according to claim 1 is characterized in that: In the security door component pretreatment step, the degreased component surface is polished with 80-200 mesh sandpaper to achieve a surface roughness of Ra1.0-3.0 microns, and the polished component is rinsed with clean water and dried in a dry environment at a temperature of 30-60°C for 1-3 hours.

9. The method for applying environmentally friendly graphite glue shielding for security doors according to claim 1, characterized in that: In the graphite glue coating step, a spray gun is used to evenly coat the environmentally friendly graphite glue on the surface of the component, with a coating thickness of 0.5-2 mm.

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