Preparation device and preparation method of efficient wave-absorbing and heat-insulating composite material

Abstract

The invention relates to the field of heat insulation compositing, in particular to a preparation device and method of an efficient wave-absorbing and heat-insulating composite material. The preparation device comprises a lap plate and a vacuum auxiliary dipping box fixedly installed on the edge position of one side of the top surface of the lap plate; the hot-pressing drying box is detachably installed on the surface of the top of the lap joint plate and located on the edge of the other side, the nanofiber membrane is movably connected to the inner side wall face of the vacuum auxiliary dipping box and the inner side wall face of the hot-pressing drying box in a sleeving mode, and a vacuum box is arranged in the vacuum auxiliary dipping box. When the nanofiber membrane is subjected to auxiliary impregnation in the vacuum auxiliary impregnation box, the nanofiber membrane is matched with the water suction pump to absorb the magnetic slurry in the vacuum auxiliary impregnation box, the absorbed magnetic slurry is re-poured into the vacuum auxiliary impregnation box through the liquid guide pipe, and the magnetic slurry flows circularly, so that the magnetic slurry is fully dispersed in the vacuum auxiliary impregnation box. Some magnetic nanoparticles in the magnetic slurry can flow and circulate, so that the magnetic nanoparticles in some magnetic slurry are prevented from settling down.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat-insulating composites, and specifically relates to a preparation device and a preparation method for an efficient wave-absorbing and heat-insulating composite material. Background Art

[0002] With the rapid development of technology, the functions of electronic devices are becoming increasingly powerful. The problem of electromagnetic radiation generated during their operation is becoming more and more serious, and the heat dissipation requirements for the devices are also constantly increasing; in the aerospace field, aircraft fly in a complex electromagnetic environment, and materials are required to have good wave-absorbing performance to reduce the impact of electromagnetic interference on the aircraft's electronic system. In a high-temperature environment, the heat-insulating performance of materials is also crucial; in the protection of electronic devices, in order to ensure the normal operation and service life of electronic devices, materials are required to be able to effectively absorb electromagnetic radiation and insulate heat.

[0003] A patent with the publication number CN201394651Y discloses a microwave sintering device for a self-lubricating composite material, which is composed of a vacuum chamber, a heat-insulating plate, a special sintering furnace chamber, a microwave generator and a far-infrared thermometer. The special sintering furnace chamber is composed of a heat-insulating ceramic layer, a SiC wave-absorbing layer and a heat storage and heat conduction ceramic layer; a layer of copper powder is evenly covered on the base steel plate, and the copper powder-coated steel plate is microwave pre-sintered, and then heated to different temperatures at different time periods for high-temperature sintering to weld and bond the base steel plate and the copper powder together; a layer of PTFE is attached to the surface and rolled flat, and then sintered again at different temperatures at different time periods to volatilize the water and alcohol in the PTFE and cause a cross-linking reaction to form a stable and reliable lubricating layer. It can realize the microwave indirect sintering preparation of a three-layer self-lubricating composite material composed of a base layer steel plate, an intermediate layer bronze powder and a surface layer PTFE, and has the characteristics of rapid and uniform heating, small floor area, short sintering time and low energy consumption.

[0004] Currently, in the existing technology, traditional wave-absorbing materials and heat-insulating materials often have single functions and are difficult to meet the dual requirements of wave absorption and heat insulation at the same time. Some wave-absorbing materials can absorb electromagnetic waves, but their heat-insulating performance is poor; while heat-insulating materials perform poorly in wave absorption. Some multifunctional materials have problems such as complex preparation processes, high costs and unstable performance.

[0005] Therefore, the present invention provides a preparation device and a preparation method for an efficient wave-absorbing and heat-insulating composite material. Summary of the Invention

[0006] In order to make up for the deficiencies of the existing technology and solve at least one of the technical problems proposed in the background art.

[0007] First aspect, the technical solution adopted by the present invention to solve its technical problems is as follows: A preparation device for an efficient wave-absorbing and heat-insulating composite material of the present invention includes a lap joint plate and a vacuum-assisted impregnation box fixedly installed on one side edge position of the top surface of the lap joint plate, a hot pressing and drying box detachably installed on the top surface of the lap joint plate and located on the other side edge position, and a nanofiber membrane movably sleeved on the inner side wall surfaces of the vacuum-assisted impregnation box and the hot pressing and drying box. A vacuum box is arranged inside the vacuum-assisted impregnation box. Double-roller extrusion rods are movably sleeved on the inner side wall surfaces of the vacuum-assisted impregnation box and located on both side edge positions. Auxiliary rods that movably lap on the outer surface of the nanofiber membrane are respectively movably sleeved on the inner side wall surfaces of the vacuum-assisted impregnation box and located on the upper and lower side edge positions. The outer surface of the nanofiber membrane respectively movably laps on the outer surfaces of the double-roller extrusion rods and the auxiliary rods. The inside of the vacuum-assisted impregnation box is filled with magnetic slurry, and the magnetic slurry is located at the bottom edge position of the middle auxiliary rod.

[0008] Preferably, a horizontal line is arranged at the middle position of the inner side wall surface of the vacuum-assisted impregnation box. Water pumps are fixedly installed on the top surface of the vacuum-assisted impregnation box and located on both side edge positions. A liquid guide pipe arranged on the top surface of the vacuum-assisted impregnation box is fixedly connected to the output end of the water pump. The input end of the water pump extends into the inside of the vacuum-assisted impregnation box and is located at the bottom edge position of the horizontal line.

[0009] Preferably, a cavity is formed inside the auxiliary rod. Elastic wires are fixedly connected to the inner side wall surface of the auxiliary rod and located inside the cavity. The other ends of the elastic wires extend to the outer side wall surface of the auxiliary rod. A semi-circular extrusion strip that movably laps on the outer surface of the auxiliary rod is fixedly connected to one end of the auxiliary rod.

[0010] Preferably, motors two are fixedly installed on both side surfaces of the hot pressing and drying box. Extrusion rods movably sleeved on the outer side surface of the hot pressing and drying box are fixedly connected to the output ends of the motors two. Limiting plates are fixedly connected to the concave outer surfaces of the extrusion rods. Circular grooves that movably lap on the outer surface of the nanofiber membrane are arranged on the outer surface of the extrusion rods. The outer surface of the extrusion rods and located on one side edge position of the limiting plate movably laps on the outer surface of the nanofiber membrane. Auxiliary soft sleeves are fixedly connected to both side surfaces of the hot pressing and drying box. The outer surface of the nanofiber membrane is movably sleeved on the inner side wall surface of the auxiliary soft sleeves. Two groups of heating boxes are fixedly installed on the top surface of the hot pressing and drying box and located on both side edge positions. A blower is fixedly installed on the output end of the left heating box. A gas guide pipe arranged on the outer surface of the heating box is fixedly connected to the output end of the blower. Exhaust pipes are fixedly installed on the outer surfaces of the two groups of heating boxes. The other ends of the exhaust pipes extend to the inner side wall surface of the hot pressing and drying box.

[0011] Preferably, support plates are fixedly installed on the top surface of the lapping plate and at both edge positions of the vacuum-assisted impregnation tank. A first motor is fixedly installed on the outer surface of the support plate, and the output end of the first motor is fixedly connected to the outer surface of the double-roller extrusion rod.

[0012] Second aspect, a preparation method of an efficient wave-absorbing and heat-insulating composite material, comprising the following steps: S1. Mix carbon nanotubes with a polyimide solution to form a spinning solution, and prepare a nanofiber membrane from the spinning solution by electrospinning technology; S2. At the same time, uniformly disperse magnetic nanoparticles in epoxy resin to prepare a magnetic slurry; S3. At the same time, use a vacuum-assisted impregnation tank to fully penetrate the magnetic slurry into the nanofiber membrane; S4. After the nanofiber membrane is prepared, use a hot pressing and drying oven to dry and shape the nanofiber membrane, and the formed nanofiber membrane will form a new wave-absorbing and heat-insulating composite material.

[0013] Preferably, the S1 further comprises the following steps: The mass ratio of the carbon nanotubes in the spinning solution is 0.5% - 3%, and the mass concentration of the polyimide solution is 15% - 25%; The process parameters of the electrospinning technology are: voltage 15 - 25 kV, nozzle flow rate 0.5 mL / h - 1.5 mL / h, and receiving distance 10 cm - 20 cm.

[0014] Preferably, the S2 further comprises the following steps: The magnetic nanoparticles are carbonyl iron powder, ferrite particles and magnetic ceramic particles, and the mass ratio in the magnetic slurry is 20% - 50%.

[0015] Preferably, the S3 further comprises the following steps: The vacuum degree of the vacuum-assisted impregnation tank is ≤ -0.09 MPa, and the impregnation time is 10 - 30 minutes.

[0016] Preferably, the S4 further comprises the following steps: The drying of the hot pressing and drying oven is normal temperature drying for 24 hours, the temperature of hot pressing and forming is 80 - 120 °C, the pressure is 5 MPa - 10 MPa, and the hot pressing time is 1 - 2 hours.

[0017] The beneficial effects of the present invention are as follows: 1. For the preparation device and method of an efficient wave-absorbing and heat-insulating composite material according to the present invention, after the nanofiber membrane is prepared, the nanofiber membrane is moved into the interior of the vacuum-assisted impregnation tank, and multiple auxiliary rods on the inner side wall surface of the vacuum-assisted impregnation tank are used to stagger and overlap the nanofiber membrane up and down, and the nanofiber membrane is tightened. When the nanofiber membrane moves inside the vacuum-assisted impregnation tank, the nanofiber membrane is completely immersed in the magnetic slurry. When the nanofiber membrane crosses the horizontal line, the nanofiber membrane is extruded by the semi-circular extrusion strip a on the outer surface of the auxiliary rod to clean the excess magnetic slurry on the surface of the nanofiber membrane. Subsequently, the nanofiber membrane is immersed into the magnetic slurry again. By the up-and-down extrusion movement of the auxiliary rod, the magnetic slurry is compressed, expanded, and soaked inside the nanofiber membrane, so that the magnetic slurry can penetrate into the nanofiber membrane to a great extent. 2. For the preparation device and method of an efficient wave-absorbing and heat-insulating composite material according to the present invention, while the nanofiber membrane is being assisted in impregnation inside the vacuum-assisted impregnation tank, a water pump is used to absorb the magnetic slurry inside the vacuum-assisted impregnation tank, and the absorbed magnetic slurry is re-injected into the vacuum-assisted impregnation tank through a liquid guide pipe. Under the circulating flow of the magnetic slurry, some magnetic nanoparticles inside the magnetic slurry can be circulated, preventing some magnetic nanoparticles inside the magnetic slurry from settling, and thus avoiding the effect that the density of the magnetic slurry will be lower than the density of the magnetic slurry under normal conditions. 3. For the preparation device and method of an efficient wave-absorbing and heat-insulating composite material according to the present invention, after the nanofiber membrane is magnetically impregnated, the nanofiber membrane is moved into the interior of the hot pressing and drying oven. An auxiliary soft shell is used to limit the position of the nanofiber membrane, and the connection between the nanofiber membrane and the auxiliary soft shell is supported by padding, so that the nanofiber membrane can enter the interior of the hot pressing and drying oven evenly, avoiding the situation that when the nanofiber membrane enters the interior of the hot pressing and drying oven, the surface of the nanofiber membrane forms an excessive angle with the entrance of the hot pressing and drying oven, resulting in excessive friction between the nanofiber membrane and the entrance of the hot pressing and drying oven and causing the nanofiber membrane to be dragged and deformed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 is a three-dimensional view of the present invention; Figure 2 is a three-dimensional side view of the overlapping plate in the present invention; Figure 3 is a three-dimensional sectional view of the vacuum-assisted impregnation tank in the present invention; Figure 4 is a three-dimensional sectional view of the auxiliary rod in the present invention; Figure 5 is a partial sectional perspective view of the hot pressing and drying oven in the present invention; Figure 6 is a perspective view of the downward pressing of the nanofiber membrane in the present invention; Figure 7 is a process schematic diagram of the present invention.

[0020] In the figure: 11, lapping plate; 111, support plate; 112, motor 1; 12, vacuum-assisted impregnation tank; 121, vacuum tank; 122, double-roll extrusion rod; 123, auxiliary rod; a1, cavity; a2, elastic wire; a3, semi-circular extrusion strip; 124, horizontal line; 125, water pump; 126, liquid guide pipe; 13, hot pressing and drying oven; 131, motor 2; 132, extrusion rod; 133, limiting plate; 134, auxiliary soft shell; 135, heating box; 136, air guide pipe; 137, blower; 138, circular groove; 14, nanofiber membrane. Specific embodiments

[0021] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0022] Embodiment 1 As Figures 1 to 6 shown, a preparation device for an efficient wave-absorbing and heat-insulating composite material according to an embodiment of the present invention includes a lapping plate 11 and a vacuum-assisted impregnation tank 12 fixedly installed at one edge position on the top surface of the lapping plate 11, a hot pressing and drying oven 13 detachably installed on the top surface of the lapping plate 11 and located at the other edge position, a nanofiber membrane 14 movably sleeved on the inner side wall surfaces of the vacuum-assisted impregnation tank 12 and the hot pressing and drying oven 13. A vacuum tank 121 is provided inside the vacuum-assisted impregnation tank 12. Double-roll extrusion rods 122 are movably sleeved on the inner side wall surfaces of the vacuum-assisted impregnation tank 12 and located at both edge positions. Auxiliary rods 123 are movably sleeved on the inner side wall surfaces of the vacuum-assisted impregnation tank 12 and located at the upper and lower edge positions respectively, and are movably lapped on the outer surface of the nanofiber membrane 14. The outer surface of the nanofiber membrane 14 is respectively movably lapped on the outer surfaces of the double-roll extrusion rods 122 and the auxiliary rods 123. The inside of the vacuum-assisted impregnation tank 12 is filled with magnetic slurry, and the magnetic slurry is located at the bottom edge position of the middle auxiliary rod 123; A horizontal line 124 is provided at the middle position on the inner side wall surface of the vacuum-assisted impregnation tank 12. Water pumps 125 are fixedly installed at both edge positions on the top surface of the vacuum-assisted impregnation tank 12. A liquid guide pipe 126 provided on the top surface of the vacuum-assisted impregnation tank 12 is fixedly connected to the output end of the water pump 125. The input end of the water pump 125 extends into the vacuum-assisted impregnation tank 12 and is located at the bottom edge position of the horizontal line 124; A cavity a1 is formed inside the auxiliary rod 123. A resilient wire a2 is fixedly connected to the inner wall surface of the auxiliary rod 123 and inside the cavity a1. The other end of the resilient wire a2 extends to the outer wall surface of the auxiliary rod 123. One end of the auxiliary rod 123 is fixedly connected to a semi-circular extrusion strip a3 that movably overlaps on the outer surface of the auxiliary rod 123.

[0023] After the nanofiber membrane 14 is prepared, the nanofiber membrane 14 is moved into the interior of the vacuum-assisted impregnation tank 12. At this time, the motor one 112 is used to rotate the double-roller extrusion rod 122, and then the nanofiber membrane 14 on the outer surface of the double-roller extrusion rod 122 is driven and conveyed into the interior of the vacuum-assisted impregnation tank 12. The nanofiber membrane 14 is alternately overlapped up and down by multiple auxiliary rods 123 on the inner wall surface of the vacuum-assisted impregnation tank 12, and the nanofiber membrane 14 is tightened. When the nanofiber membrane 14 moves inside the vacuum-assisted impregnation tank 12, the nanofiber membrane 14 is completely immersed in the magnetic slurry. When the nanofiber membrane 14 crosses the horizontal line 124, the semi-circular extrusion strip a3 on the outer surface of the auxiliary rod 123 is used to squeeze the nanofiber membrane 14, and the excess magnetic slurry on the surface of the nanofiber membrane 14 is cleaned off. Subsequently, the nanofiber membrane 14 is immersed into the magnetic slurry again. By the up-and-down squeezing movement of the auxiliary rod 123, the magnetic slurry is compressed, expanded, and immersed inside the nanofiber membrane 14, so that the magnetic slurry can penetrate into the nanofiber membrane 14 to a great extent. While the nanofiber membrane 14 is being assisted in impregnation inside the vacuum-assisted impregnation tank 12, the magnetic slurry inside the vacuum-assisted impregnation tank 12 is absorbed by the water pump 125 and re-injected into the vacuum-assisted impregnation tank 12 through the liquid guide pipe 126. Under the circulating flow of the magnetic slurry, some magnetic nanoparticles inside the magnetic slurry can be circulated, avoiding the sedimentation of some magnetic nanoparticles inside the magnetic slurry, which would otherwise cause the density of the magnetic slurry to be lower than the density of the magnetic slurry under normal conditions.

[0024] Such as Figure 1 - Figure 3 and Figure 5 - Figure 6As shown in the figure, on both side surfaces of the hot pressing drying oven 13, a second motor 131 is fixedly installed. The output end of the second motor 131 is fixedly connected to an extrusion rod 132 that is movably sleeved on the outer surface of the hot pressing drying oven 13. On the concave outer surface of the extrusion rod 132, a limiting plate 133 is fixedly connected. On the outer surface of the extrusion rod 132, a circular groove 138 is provided that movably overlaps on the outer surface of the nanofiber membrane 14. The outer surface of the extrusion rod 132 and at one side edge position of the limiting plate 133 movably overlaps on the outer surface of the nanofiber membrane 14. On both side surfaces of the hot pressing drying oven 13, an auxiliary soft sleeve 134 is fixedly connected. The outer surface of the nanofiber membrane 14 is movably sleeved on the inner wall surface of the auxiliary soft sleeve 134. On the top surface of the hot pressing drying oven 13 and at both side edge positions, two heating boxes 135 are fixedly installed. On the output end of the left heating box 135, a blower 137 is fixedly installed. The output end of the blower 137 is fixedly connected to an air duct 136 provided on the outer surface of the heating box 135. On the outer surfaces of the two heating boxes 135, an exhaust pipe is fixedly installed, and the other end of the exhaust pipe extends to the inner wall surface of the hot pressing drying oven 13; on the top surface of the overlapping plate 11 and at both side edge positions of the vacuum-assisted impregnation tank 12, a support plate 111 is fixedly installed. On the outer surface of the support plate 111, a first motor 112 is fixedly installed. The output end of the first motor 112 is fixedly connected to the outer surface of the double-roll extrusion rod 122.

[0025] After the nanofiber membrane 14 is magnetically impregnated, the nanofiber membrane 14 is moved into the interior of the hot pressing drying oven 13. The auxiliary soft sleeve 134 is used to limit the position of the nanofiber membrane 14, and the connection between the nanofiber membrane 14 and the auxiliary soft sleeve 134 is elevated and supported, so that the nanofiber membrane 14 can enter the interior of the hot pressing drying oven 13 evenly. This avoids the situation where when the nanofiber membrane 14 enters the interior of the hot pressing drying oven 13, the surface of the nanofiber membrane 14 forms an excessive angle with the entrance of the hot pressing drying oven 13, which may lead to excessive friction between the nanofiber membrane 14 and the entrance of the hot pressing drying oven 13, resulting in dragging and deformation of the nanofiber membrane 14. When the nanofiber membrane 14 enters the hot press drying box 13, two auxiliary soft shells 134 are used to increase the friction of the nanofiber membrane 14, so that the nanofiber membrane 14 can maintain a large tension while being pulled. At this time, the extrusion rod 132 is rotated by the second motor 131, and the extrusion rod 132 hits the outer surface of the nanofiber membrane 14 while rotating. Each time the extrusion rod 132 hits the surface of the nanofiber membrane 14, the nanofiber membrane 14 will sink slightly. When the extrusion rod 132 leaves the surface of the nanofiber membrane 14, the nanofiber membrane 14 will reset. In the process of high-frequency sinking and resetting, the residual magnetic nanoparticles on the surface of the nanofiber membrane 14 will be cleaned up, and the multiple tensioning and resetting of the nanofiber membrane 14 will also make some magnetic nanoparticles more firmly adhere to the surface of the nanofiber membrane 14. The blower 137 is used to absorb gas from one side wall of the hot press drying box 13, and the absorbed gas is preliminarily heated by a group of heating boxes 135 on the outer surface of the blower 137, and the gas is injected into the inside of another group of heating boxes 135 through the air duct 136, and the flowing gas is subjected to secondary circulation heating treatment, and the heated hot gas is re-injected into the hot press drying box 13, so that the gas can fully contact with the surface of the nanofiber membrane 14 under the circulation flow, and then the sealed environment inside the hot press drying box 13 is used to make the interior of the hot press drying box 13 always in a high temperature and high pressure environment, so that the nanofiber membrane 14 gradually forms a wave-absorbing and heat-insulating material.

[0026] Example 2 like Figure 7 As shown, a method for preparing a high-efficiency wave-absorbing and heat-insulating composite material comprises the following steps: S1, mixing carbon nanotubes and polyimide solution to form a spinning solution, and preparing the spinning solution into a nanofiber membrane 14 by electrospinning technology; S2, while uniformly dispersing magnetic nanoparticles in epoxy resin to prepare a magnetic slurry; S3, using the vacuum-assisted impregnation box 12 to fully infiltrate the magnetic slurry into the nanofiber membrane 14; S4. After the nanofiber membrane 14 is prepared, a hot press drying oven 13 is used to dry and shape the nanofiber membrane 14. The formed nanofiber membrane 14 will form a new wave-absorbing and heat-insulating composite material.

[0027] S1 also includes the following steps: The mass proportion of carbon nanotubes in the spinning solution is 0.5%, and the mass concentration of the polyimide solution is 15%; The process parameters of electrospinning technology are: voltage 15 kV, nozzle flow rate 0.5 mL / h, and receiving distance 10 cm.

[0028] S2 also includes the following steps: The magnetic nanoparticles are carbonyl iron powder, ferrite particles and magnetic ceramic particles, and the mass ratio in the magnetic slurry is 20%.

[0029] S3 also includes the following steps: The vacuum degree of the vacuum-assisted impregnation box 12 ≤ -0.09 MPa, and the impregnation time is 10 minutes.

[0030] S4 also includes the following steps: The drying in the hot-pressing drying box 13 is normal-temperature drying for 24 hours, the temperature of hot-pressing forming is 80 °C, the pressure is 5 MPa, and the hot-pressing time is 1 hour.

[0031] Example 3 As Figure 7 shown, a preparation method of an efficient electromagnetic wave absorbing and heat insulating composite material includes the following steps: S1. Mix carbon nanotubes with a polyimide solution to form a spinning solution, and prepare a nanofiber membrane 14 from the spinning solution by electrospinning technology; S2. At the same time, uniformly disperse magnetic nanoparticles in epoxy resin to prepare a magnetic slurry; S3. At the same time, use the vacuum-assisted impregnation box 12 to fully penetrate the magnetic slurry into the nanofiber membrane 14; S4. After the nanofiber membrane 14 is prepared, use the hot-pressing drying box 13 to dry and shape the nanofiber membrane 14, and the formed nanofiber membrane 14 will form a new electromagnetic wave absorbing and heat insulating composite material.

[0032] S1 also includes the following steps: The mass ratio of carbon nanotubes in the spinning solution is 1.5%, and the mass concentration of the polyimide solution is 20%; The process parameters of the electrospinning technology are: voltage 20 kV, nozzle flow rate 1 mL / h, and receiving distance 15 cm.

[0033] S2 also includes the following steps: The magnetic nanoparticles are carbonyl iron powder, ferrite particles and magnetic ceramic particles, and the mass ratio in the magnetic slurry is 30%.

[0034] S3 also includes the following steps: The vacuum degree of the vacuum-assisted impregnation box 12 ≤ -0.09 MPa, and the impregnation time is 20 minutes.

[0035] S4 also includes the following steps: The drying in the hot-pressing drying box 13 is normal-temperature drying for 24 hours, the temperature of hot-pressing forming is 100 °C, the pressure is 8 MPa, and the hot-pressing time is 1.5 hours.

[0036] Example 4 As Figure 7 shown, a method for preparing an efficient wave-absorbing and heat-insulating composite material includes the following steps: S1. Mix carbon nanotubes with a polyimide solution to form a spinning solution, and prepare a nanofiber membrane 14 from the spinning solution by electrospinning technology; S2. At the same time, uniformly disperse magnetic nanoparticles in epoxy resin to prepare a magnetic slurry; S3. At the same time, use a vacuum-assisted impregnation box 12 to fully penetrate the magnetic slurry into the interior of the nanofiber membrane 14; S4. After the nanofiber membrane 14 is prepared, use a hot-pressing drying oven 13 to dry and shape the nanofiber membrane 14, and the formed nanofiber membrane 14 will form a new wave-absorbing and heat-insulating composite material.

[0037] S1 also includes the following steps: The mass ratio of carbon nanotubes in the spinning solution is 3%, and the mass concentration of the polyimide solution is 25%; The process parameters of the electrospinning technology are: voltage 25 kV, nozzle flow rate 1.5 mL / h, and receiving distance 20 cm.

[0038] S2 also includes the following steps: The magnetic nanoparticles are carbonyl iron powder, ferrite particles and magnetic ceramic particles, and the mass ratio in the magnetic slurry is 50%.

[0039] S3 also includes the following steps: The vacuum degree of the vacuum-assisted impregnation box 12 ≤ -0.09 MPa, and the impregnation time is 30 minutes.

[0040] S4 also includes the following steps: The drying in the hot-pressing drying oven 13 is normal-temperature drying for 24 hours, the temperature of hot-pressing forming is 120 °C, the pressure is 10 MPa, and the hot-pressing time is 2 hours.

[0041] Working principle: After the nanofiber membrane 14 is prepared, the nanofiber membrane 14 is moved into the interior of the vacuum-assisted impregnation box 12. At this time, the motor 112 is used to rotate the double-roller extrusion rod 122, and then the nanofiber membrane 14 on the outer surface of the double-roller extrusion rod 122 is driven and conveyed into the interior of the vacuum-assisted impregnation box 12. The nanofiber membrane 14 is overlapped up and down in a staggered manner by multiple auxiliary rods 123 on the inner side wall of the vacuum-assisted impregnation box 12, and the nanofiber membrane 14 is tightened. When the nanofiber membrane 14 moves inside the vacuum-assisted impregnation box 12, the nanofiber membrane 14 is completely immersed in the magnetic slurry. When the nanofiber membrane 14 crosses the horizontal line 124, the semicircular extrusion strip a3 on the outer surface of the auxiliary rod 123 is used to extrude the nanofiber membrane 14, and the excess magnetic slurry on the surface of the nanofiber membrane 14 is cleaned up. Then, the nanofiber membrane 14 is immersed in the magnetic slurry again. By the up-and-down extrusion movement of the auxiliary rod 123, the magnetic slurry is compressed, expanded, and immersed inside the nanofiber membrane 14, so that the magnetic slurry can penetrate into the interior of the nanofiber membrane 14 to a great extent; While the nanofiber membrane 14 is being assisted and impregnated inside the vacuum-assisted impregnation box 12, the water pump 125 is used to absorb the magnetic slurry inside the vacuum-assisted impregnation box 12, and the absorbed magnetic slurry is re-injected into the interior of the vacuum-assisted impregnation box 12 through the liquid guide pipe 126. Under the circulating flow of the magnetic slurry, some magnetic nanoparticles inside the magnetic slurry can be circulated, avoiding the sedimentation of some magnetic nanoparticles inside the magnetic slurry, which would otherwise lead to the density of the magnetic slurry being lower than the density of the magnetic slurry under normal conditions; After the magnetic impregnation of the nanofiber membrane 14 is completed, the nanofiber membrane 14 is moved into the interior of the hot-pressing drying box 13. The position of the nanofiber membrane 14 is limited by the auxiliary soft shell 134, and the connection between the nanofiber membrane 14 and the auxiliary soft shell 134 is raised and supported, so that the nanofiber membrane 14 can enter the interior of the hot-pressing drying box 13 evenly, avoiding the situation where the surface of the nanofiber membrane 14 forms too large an angle with the entrance of the hot-pressing drying box 13 when the nanofiber membrane 14 enters the interior of the hot-pressing drying box 13, which would otherwise lead to too large a frictional force between the nanofiber membrane 14 and the entrance of the hot-pressing drying box 13 and cause the nanofiber membrane 14 to be dragged and deformed; When the nanofiber membrane 14 enters the interior of the hot-pressing drying oven 13, two auxiliary soft sheaths 134 are used to increase the friction force of the nanofiber membrane 14, so that when the nanofiber membrane 14 is pulled, the nanofiber membrane 14 can maintain a large tension force. At this time, the second motor 131 rotates the extrusion rod 132, and while the extrusion rod 132 rotates, it impacts the outer surface of the nanofiber membrane 14. Each time the extrusion rod 132 impacts the surface of the nanofiber membrane 14, the nanofiber membrane 14 will produce a slight depression. When the extrusion rod 132 leaves the surface of the nanofiber membrane 14, the nanofiber membrane 14 will reset. During the process of high-frequency depression and reset, the residual magnetic nanoparticles on the surface of the nanofiber membrane 14 will be cleaned off, and the multiple tensioning and resetting of the nanofiber membrane 14 will also make some magnetic nanoparticles adhere more firmly to the surface of the nanofiber membrane 14.

[0042] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An apparatus for preparing an efficient wave-absorbing and heat-insulating composite material, comprising a lapping plate (11) and a vacuum-assisted impregnation tank (12) fixedly installed at one edge position on the top surface of the lapping plate (11), a hot pressing and drying tank (13) detachably installed on the top surface of the lapping plate (11) and located at the other edge position, and a nanofiber membrane (14) movably sleeved on the inner side wall surfaces of the vacuum-assisted impregnation tank (12) and the hot pressing and drying tank (13), characterized in that: Inside the vacuum-assisted impregnation tank (12), there is a vacuum tank (121). On the inner side wall of the vacuum-assisted impregnation tank (12) and at both side edge positions, there is a double-roller extrusion rod (122) movably sleeved. On the inner side wall of the vacuum-assisted impregnation tank (12) and at the upper and lower side edge positions respectively, there is an auxiliary rod (123) movably sleeved and overlapping on the outer surface of the nanofiber membrane (14). And the outer surface of the nanofiber membrane (14) respectively movably overlaps on the outer surfaces of the double-roller extrusion rod (122) and the auxiliary rod (123). The inside of the vacuum-assisted impregnation tank (12) is filled with magnetic slurry, and the magnetic slurry is at the bottom edge position of the middle auxiliary rod (123).

2. The preparation device of an efficient wave-absorbing and heat-insulating composite material according to claim 1, characterized in that: On the inner side wall of the vacuum-assisted impregnation tank (12) and at the middle position, there is a horizontal line (124). On the top surface of the vacuum-assisted impregnation tank (12) and at both side edge positions, there is a water pump (125) fixedly installed. On the output end of the water pump (125), there is a liquid guide pipe (126) arranged on the top surface of the vacuum-assisted impregnation tank (12). The input end of the water pump (125) extends into the vacuum-assisted impregnation tank (12) and is at the bottom edge position of the horizontal line (124).

3. The preparation device of an efficient wave-absorbing and heat-insulating composite material according to claim 2, characterized in that: Inside the auxiliary rod (123), there is a cavity (a1). On the inner side wall of the auxiliary rod (123) and inside the cavity (a1), there is an elastic wire (a2) fixedly connected. The other end of the elastic wire (a2) extends to the outer side wall of the auxiliary rod (123). On one end of the auxiliary rod (123), there is a semi-circular extrusion strip (a3) movably overlapping on the outer surface of the auxiliary rod (123).

4. The preparation device of an efficient wave-absorbing and heat-insulating composite material according to claim 1, characterized in that: On both side surfaces of the hot pressing drying oven (13), a second motor (131) is fixedly installed. The output end of the second motor (131) is fixedly connected to a pressing rod (132) movably sleeved on the outer surface of the hot pressing drying oven (13). On the concave outer surface of the pressing rod (132), a limiting plate (133) is fixedly connected. On the outer surface of the pressing rod (132), a circular groove (138) is arranged which movably lapped on the outer surface of the nanofiber membrane (14). On the outer surface of the pressing rod (132) and at one side edge position of the limiting plate (133), it movably lapped on the outer surface of the nanofiber membrane (14). On both side surfaces of the hot pressing drying oven (13), an auxiliary soft sleeve (134) is fixedly connected. The outer surface of the nanofiber membrane (14) is movably sleeved on the inner wall surface of the auxiliary soft sleeve (134). On the top surface of the hot pressing drying oven (13) and at both side edge positions, two heating boxes (135) are fixedly installed. On the output end of the left heating box (135), a blower (137) is fixedly installed. On the output end of the blower (137), an air duct (136) arranged on the outer surface of the heating box (135) is fixedly connected. On the outer surface of the two heating boxes (135), an exhaust pipe is fixedly installed. The other end of the exhaust pipe extends to the inner wall surface of the hot pressing drying oven (13).

5. The preparation device of an efficient wave-absorbing and heat-insulating composite material according to claim 1, wherein: On the top surface of the lapping plate (11) and at both side edge positions of the vacuum-assisted impregnation box (12), a support plate (111) is fixedly installed. On the outer surface of the support plate (111), a first motor (112) is fixedly installed. The output end of the first motor (112) is fixedly connected to the outer surface of the double-roll pressing rod (122).

6. A preparation method of an efficient wave-absorbing and heat-insulating composite material, applicable to a preparation device of an efficient wave-absorbing and heat-insulating composite material according to any one of claims 1-5, characterized in that: It includes the following steps: S1. Mix carbon nanotubes with a polyimide solution to form a spinning solution, and prepare the spinning solution into a nanofiber membrane (14) by electrospinning technology; S2. At the same time, uniformly disperse magnetic nanoparticles in epoxy resin to prepare a magnetic slurry; S3. At the same time, use the vacuum-assisted impregnation box (12) to fully penetrate the magnetic slurry into the nanofiber membrane (14); S4. After the nanofiber membrane (14) is prepared, use the hot pressing drying oven (13) to dry and shape the nanofiber membrane (14). The formed nanofiber membrane (14) will form a new wave-absorbing and heat-insulating composite material.

7. The preparation method of an efficient wave-absorbing and heat-insulating composite material according to claim 6, characterized in that: The S1 further includes the following steps: The mass ratio of the carbon nanotubes in the spinning solution is 0.5% - 3%, and the mass concentration of the polyimide solution is 15% - 25%; The process parameters of the electrospinning technology are: voltage 15 - 25 kV, nozzle flow rate 0.5 mL / h - 1.5 mL / h, receiving distance 10 cm - 20 cm.

8. The preparation method of an efficient wave-absorbing and heat-insulating composite material according to claim 6, wherein: The S2 further includes the following steps: The magnetic nanoparticles are carbonyl iron powder, ferrite particles and magnetic ceramic particles, and the mass ratio in the magnetic slurry is 20% - 50%.

9. The preparation method of an efficient wave-absorbing and heat-insulating composite material according to claim 6, characterized in that: The S3 further includes the following steps: The vacuum degree of the vacuum-assisted impregnation box (12) ≤ -0.09 MPa, and the impregnation time is 10 - 30 minutes.

10. The preparation method of an efficient wave-absorbing and heat-insulating composite material according to claim 6, characterized in that: S4 further includes the following steps: The drying in the hot pressing and drying oven (13) is at normal temperature for 24 hours, the temperature for hot pressing and forming is 80 - 120 °C, the pressure is 5 MPa - 10 MPa, and the hot pressing time is 1 - 2 hours.

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