Integrated forming equipment and method for ultrahigh-strength polyimide-based composite foam with electromagnetic wave absorption function
By adding multi-walled carbon nanotubes and carbonyl iron powder to the polyimide material, and using magnetic field rotation and air pressure adjustment technology, the problems of both mechanical strength and absorption performance of polyimide materials are solved, achieving efficient preparation of super-imide materials High-strength polyimide composite foam.
Patent Information
- Application Number
- CN202411310397.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-19
- Publication Date
- 2024-12-31
AI Technical Summary
The existing polyimide materials have low compressive strength and cannot take into account excellent absorbance and mechanical strength. The foam prepared by the free foaming method has uneven pore size and insufficient mixing due to the lack of external binding force, which affects product quality.
The coordinated strengthening of multi-wall carbon nanotubes and rigid carbonyl iron powder is adopted to achieve uniform mixing and foaming control of materials through the rapid rotation of different materials under the action of magnetic fields. Combined with air pressure adjustment and heating devices, an integrated molding equipment is designed to Improve mechanical strength and wave absorption performance.
The preparation of ultra-high-strength polyimide composite foam is achieved, solving the problems of both mechanical strength and wave absorption performance, and ensuring the uniformity of the foam and the efficient preparation process.
Smart Images
Figure CN119217631A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of chemical synthesis and engineering application, and in particular relates to the preparation of ultra-high strength hard foam with electromagnetic wave absorption function. Background Art
[0002] In order to cope with the increasing number of high-performance radar-guided missiles and interceptors on the modern battlefield, the constantly upgraded stealth technology (or low observable technology) is an indispensable and important factor in the design of most new aircraft, ships, missiles, satellites and submarines, so as to make them invisible to infrared, radar and other detection methods. With the continuous development of absorbing materials, polymer-based composite absorbing materials are becoming more and more popular. In addition to its excellent mechanical properties, controllable complex dielectric constant, and easy synthesis process, the designed three-dimensional mutual propagation hole interface of polymer-based composite absorbing materials produces strong polarization and scattering effects in the alternating electromagnetic field, which can further improve the working efficiency of microwave absorbers. As a polymer material at the top of the pyramid, polyimide itself has excellent physical and chemical stability and excellent resistance to extremely high / low temperatures. It can meet the functional requirements of modern national defense under extreme conditions. However, with the continuous improvement of the requirements for special engineering materials as the main or direct bearing parts in the aerospace field, the compression strength of existing polyimide materials with absorbing properties is mostly low by 10Mpa, which cannot take into account the excellent absorbing performance while achieving the required mechanical strength. Therefore, exploring high-load-bearing-capacity absorbing materials remains a meaningful and challenging topic.
[0003] Common methods for preparing foams mainly include freeze drying, supercritical physical foaming, spray drying, free foaming, etc. Among them, the free foaming method is widely used in efficient foam preparation due to its simple process, fast production speed, good uniformity and other advantages. However, the foam prepared by the free foaming method will cause uneven cell size during the free foaming process due to the lack of external constraints, and the various mixed materials in the foaming process will not be fully mixed in a short time due to the difference in viscosity, thus affecting the final quality of the product. The most important thing is that pure polyimide foam has low mechanical strength and cannot meet the requirements of practical applications. Therefore, it is proposed to add suitable fillers to the polyimide matrix to improve the overall mechanical strength. Multi-walled carbon nanotubes are widely used in various absorbing materials due to their adjustable electrical properties, high carrier mobility, excellent mechanical properties, low density and large specific surface area, and agglomerated multi-walled carbon nanotubes can effectively thicken the thickness of the polyimide foam wall skeleton to improve its mechanical strength. In addition, the mechanical properties of the composite material can be improved by adding reinforcing phase particles. The composite foam produced by incorporating rigid particles into the polymer matrix usually has higher specific performance than traditional polymer foam. Therefore, this patent innovatively uses the synergistic strengthening effect of multi-walled carbon nanotubes and rigid carbonyl iron powder to explore the appropriate filling ratio and design an integrated molding device that can control the foaming speed and improve the mixing uniformity of the mixed slurry. Summary of the invention
[0004] In view of the problems existing in the prior art, the present invention provides an ultra-high strength polyimide-based composite foam integrated molding device and method with electromagnetic wave absorption function. The heterogeneous material storage chamber can rotate rapidly under the action of a magnetic field to fully stir the mixed material in the main reaction chamber, wherein the heterogeneous material slowly flows into the main reaction chamber according to the rotation speed and is evenly mixed with the material, and the material in the reaction chamber can be heated by a heating device to meet the requirements of different reaction temperatures of different materials. The external gas flow cabinet can adjust the air pressure in the tank in real time to control the foaming rate to prevent local uneven mixing caused by rapid foam formation during free vertical foaming. The lightweight balance bar in the heterogeneous material storage chamber provides a restraining force during the rotation of the cavity to prevent the cavity from tipping over or deviating from the rotation track. The small ball at the bottom of the balance bar attracts the bottom magnetic particles in the late stage of mixing for easy recovery. The absorption and release of the heterogeneous material storage chamber is achieved by controlling the current of the cover plate of the main reaction chamber, and the whole process is simple and efficient.
[0005] The present invention is achieved through the following technical solutions:
[0006] An ultra-high strength polyimide-based composite foam molding device and method with electromagnetic wave absorption function, characterized in that it includes an outer tank, a main reaction chamber cover, a heterogeneous material storage chamber, a main reaction chamber, an electromagnetic conversion chamber, a temperature control system, a wiring port, and a central processing system.
[0007] The top cover of the outer tank is connected to the tank body with a clamp. One port on the cover is connected to an air flow pressure display to monitor the air pressure inside the tank in real time, and the other port is connected to a gas flow cabinet to control the air pressure inside the tank in real time.
[0008] The main reaction chamber cover is made of a ring-shaped electromagnet with a coil wrapped around it. There are array holes on the surface of the electromagnet, which can ensure that the air pressure in the reaction chamber is consistent with that in the outer tank after the cover is tightened. The inner ring mouth absorbs the foreign material storage cavity when power is turned on. The ring mouth design makes it easy to add materials to the storage cavity at any time after the cover is closed and to expose the balance bar.
[0009] The heterogeneous material storage chamber is made of light magnetic material. A hole is opened at the axis position and a light rod is set. The rod diameter is slightly smaller than the axis hole diameter, which is convenient for the light rod to move up and down in the storage chamber without excessive tilting. A flat cylindrical round cap is made on the upper part of the light rod, and the cap diameter is larger than the axis hole diameter to prevent the light rod from slipping out. A small magnet is fixed on the upper part of the light rod, which adsorbs the magnetic stirring bar at the lower part when the material in the storage chamber flows out. The funnel-shaped design at the bottom of the storage chamber facilitates the outflow of viscous materials and reduces adhesion. The annular bearing is fixed at the mouth of the funnel, and four rotating blades are set outside the bearing. Under the controllable super-strong magnetic field at the bottom, the bearing drives the blade to achieve high-speed rotation and stirring of materials.
[0010] The main reaction chamber is made of transparent organic glass and is detachable as a whole. In the pre-preparation stage, a polyethylene film can be coated on its surface to prevent material adhesion and facilitate product foam demoulding. There are four magnetic stirrers in the chamber.
[0011] The electromagnetic conversion chamber is composed of a motor and a magnet substrate, on which permanent magnets, coil ferromagnets, Hall elements, etc. are arranged. The magnetic field strength of the ferromagnets can be adjusted by inputting current. In addition, when the circuit is turned on, the motor rotates, and the changing magnetic field drives the magnetons in the main reaction chamber to rotate, thereby generating a magnetic stirring effect.
[0012] The temperature control system is composed of resistance heating wires, which can set the appropriate temperature according to the viscosity of the materials and the reaction temperature.
[0013] The central processing system is used to release electrical signals to control the main reaction chamber cover, resistance wire and electromagnetic conversion chamber in turn. The coil of the main reaction chamber cover is energized, and the ferromagnet attracts the heterogeneous material storage chamber. When the storage chamber is filled with materials, the power is stopped and the chamber sinks. The electromagnetic reaction chamber is energized, the magnets in the main reaction chamber rotate, the heterogeneous material storage chamber rotates rapidly, the materials flow out from the bottom, the resistance wire is energized, and the reaction is accelerated. After the mixing is completed, the electromagnetic reaction chamber stops energizing, the main reaction chamber cover is energized, and the lightweight rod attracts the magnets. The main reaction chamber cover attracts the heterogeneous material storage chamber for recovery. The central processing system is connected to the equipment through the wiring port.
[0014] An ultra-high strength polyimide-based composite foam integrated molding device and method with electromagnetic wave absorption function, characterized by adopting the following steps:
[0015] Step 1: Select two suitable foaming components, pre-treat each component, add suitable fillers and stir evenly, and place them in the main reaction chamber or the heterogeneous material storage chamber according to the proportion. The material volume of the main reaction chamber accounts for about 80% of the total volume.
[0016] Step 2: The main reaction chamber cover is powered on to generate a magnetic field to firmly hold the heterogeneous material storage chamber. The heterogeneous material storage chamber cover is opened, and materials are added until the chamber is full, and the cover is closed.
[0017] Step 3: The electromagnetic conversion chamber is powered on, the motor rotates to drive the magnet to rotate. The resistance wire is powered on, and the main chamber is heated.
[0018] Step 4: The cover of the main reaction chamber stops being powered, and the heterogeneous material storage chamber drops due to gravity, controlling the current intensity of the electromagnetic conversion chamber and increasing the magnetic field intensity. The heterogeneous material storage chamber rotates rapidly under the action of the magnetic field, driving the funnel baffle at the bottom of the storage chamber to open, and the heterogeneous material quickly flows into the vortex and mixes quickly with the material in the main reaction chamber. Open the gas flow cabinet, introduce inert gas, and adjust the gas pressure according to the reaction situation.
[0019] Step 5: The material in the heterogeneous material storage chamber decreases, the storage chamber rises under the action of the material pressure, the balance bar falls into the funnel mouth to prevent the material from flowing back, and the balance bar falls into the bottom of the main reaction chamber to attract the magnet.
[0020] Step 6: Stop energizing the electromagnetic conversion chamber and the resistance wire, and energize the main reaction chamber cover. Attract the heterogeneous material storage chamber to the top, and the lightweight balance rod absorbs the magnet to take out the reaction material. Control the airflow pressure and let it stand for foaming.
[0021] Step 7: After the foaming is completed, connect the airflow port of the outer tank to a vacuum pump to evacuate the gas in the foam to form open cells. After the pressure is released, open the main reaction chamber to demould and obtain the sample.
[0022] The present invention has at least the following advantages and effects over the prior art:
[0023] The present invention utilizes the principle of magnetic suspension rotation to make the storage chamber with heterogeneous materials rotate rapidly in the main reaction chamber. During the rotation process, the heterogeneous materials in the storage chamber flow into the vortex to achieve rapid mixing with the main material. The rotation speed can be adjusted to achieve materials with different viscosities.
[0024] The present invention controls the main reaction chamber cover through the central processing system to realize the release and recovery of the heterogeneous material storage chamber, controls the heating system to realize the adjustment of the reaction temperature of different materials, and controls the electromagnetic conversion chamber to realize the generation and stop of the strong magnetic field and the stop of the motor, thereby realizing the integrated control of the entire equipment and preparation process.
[0025] The invention controls the foaming rate in the main reaction chamber by changing different air pressures to prevent uneven local mixing caused by rapid foam formation during free vertical foaming. The inner wall of the detachable main reaction chamber is coated with a polyethylene film to facilitate foam removal and reduce adhesion.
[0026] The invention has a relatively simple structure, simple and easy technical means, and has outstanding substantial progress compared with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 It is a schematic diagram of the overall structure of an integrated molding device and method of ultra-high-strength polyimide-based composite foam with electromagnetic wave absorption function;
[0028] Figure 1 The numbers represent: 1-outer tank; 2-main reaction chamber cover; 3-heterogeneous material storage chamber; 4-main reaction chamber; 5-electromagnetic conversion chamber; 6-temperature control system; 7-wiring port; 8-central processing system; 1-1-barometer port; 1-2-gas flow cabinet / vacuum pump port; 1-3-outer tank wall; 1-4-sealing ring filling port; 2-1-main reaction chamber cover array holes; 2-2-main reaction chamber cover external coil; 2-3-main reaction chamber cover upper wiring port; 3-1-lightweight balance bar; 3-2-heterogeneous material storage chamber wall; 3-3-rotating bearing; 4-1-main reaction chamber outer wall; 4-2-magnetic stirring bar; 5-1-electromagnet; 5-2-motor.
[0029] Figure 2 It is a process flow chart of an integrated molding device and method of ultra-high strength polyimide-based composite foam with electromagnetic wave absorption function;
[0030] Figure 3 It is an enlarged schematic diagram of the main reaction chamber of an ultra-high strength polyimide-based composite foam integrated molding device with electromagnetic wave absorption function;
[0031] Figure 3 Numbers in the figure indicate: 2-1-hole array on the cover of the main reaction chamber; 2-2-external coil on the cover of the main reaction chamber; 2-3-connection port on the cover of the main reaction chamber; 4-1-outer wall of the main reaction chamber; 4-2-magnetic stirring bar; 6-temperature control system;
[0032] Figure 4It is an enlarged schematic diagram of the heterogeneous material storage chamber of an ultra-high strength polyimide-based composite foam integrated molding equipment with electromagnetic wave absorption function;
[0033] Figure 4 The numbers in the figure represent: 3-1-lightweight balance bar; 3-2-heterogeneous material storage chamber wall; 3-3-rotating bearing; 3-4-heterogeneous material storage chamber inlet cover plate; 3-5-heterogeneous material storage chamber lower funnel baffle; 3-1-1-lightweight balance bar bottom magnet; 3-3-1-rotating bearing coil; 3-3-2-rotating bearing paddle; 3-3-3-rotating bearing inner ball;
[0034] Figure 5 It is an enlarged schematic diagram of the electromagnetic conversion chamber of an ultra-high strength polyimide-based composite foam integrated molding equipment with electromagnetic wave absorption function;
[0035] Figure 5 The numbers in the figure indicate: 5-1-electromagnet; 5-2-motor; 5-3-motor terminal; 5-4-electromagnetic conversion chamber housing; 5-5-connection port under the main reaction chamber cover;
[0036] Figure 6 It is a moving schematic diagram of the preparation process of the heterogeneous material storage chamber of an ultra-high strength polyimide-based composite foam integrated molding equipment with electromagnetic wave absorption function;
[0037] Figure 6 The numbers in the figure indicate: A-schematic diagram of starting preparation; B-schematic diagram of 50% material content in the heterogeneous material storage chamber; C-schematic diagram of 0 material content in the heterogeneous material storage chamber; D-schematic diagram of recovery of the heterogeneous material storage chamber. DETAILED DESCRIPTION
[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.
[0039] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0040] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.
[0041] like Figure 1 As shown, the present invention discloses an ultra-high strength polyimide-based composite foam integrated molding equipment and method with electromagnetic wave absorption function: including an outer tank 1, a main reaction chamber cover plate 2, a heterogeneous material storage chamber 3, a main reaction chamber 4, an electromagnetic conversion chamber 5, a temperature control system 6, a wiring port 7, and a central processing system 8.
[0042] The outer tank top cover is connected to the tank body 1-3 by a clamp, one port 1-1 on the cover is connected to an external air flow pressure display to monitor the air pressure in the tank in real time, and the other port 1-2 is connected to a gas flow cabinet to control the air pressure in the tank in real time.
[0043] The main reaction chamber cover 2 is made of a circular electromagnet with a coil 2-2 wrapped around it. There is an array of holes 2-1 on the surface of the electromagnet, which can ensure that the air pressure in the reaction chamber is consistent with that in the outer tank after the cover is tightened. The inner ring mouth absorbs the foreign material storage chamber 3 when power is turned on. The ring mouth design makes it easy to add materials to the storage chamber 3 at any time after the cover is tightened and to expose the balance rod 3-1.
[0044] The heterogeneous material storage chamber 3 is made of a light magnetic material, with a hole at the axis position and a light balance rod 3-1. The rod diameter is slightly smaller than the axis hole diameter, which is convenient for the light rod to move up and down in the storage chamber without excessive tilting. The upper part of the light rod is provided with a flat cylindrical round cap, and the cap diameter is larger than the axis hole diameter to prevent the light rod from slipping out. A small magnet 3-1-1 is fixed at the bottom of the light rod, which adsorbs the lower magnetic stirring bar 4-2 when the material in the storage chamber flows out. The funnel-shaped design at the bottom of the storage chamber facilitates the outflow of viscous materials and reduces adhesion. The annular bearing 3-3 is fixed at the mouth of the funnel, and four rotating blades 3-3-3 are arranged outside the bearing. Under the controllable super-strong magnetic field at the bottom, the bearing drives the blades to achieve high-speed rotation and stirring of materials.
[0045] The main reaction chamber 4 is made of transparent organic glass and is detachable as a whole. In the pre-preparation stage, a polyethylene film can be coated on its surface to prevent material adhesion and facilitate product foam demoulding. Four magnetic stirrers 4-2 are arranged in the chamber.
[0046] The electromagnetic conversion chamber 5 is composed of a motor 5-2 and a magnet substrate, on which a permanent magnet 5-1, a coil ferromagnet, a Hall element, etc. are arranged, and the magnetic field strength of the ferromagnet can be adjusted by inputting current. In addition, when the circuit is turned on, the motor 5-2 rotates, and the changing magnetic field drives the magnet 4-2 in the main reaction chamber to rotate, so as to generate a magnetic stirring effect.
[0047] The temperature control system 6 is composed of a resistance heating wire, and the appropriate temperature is set according to different material viscosities and reaction temperatures.
[0048] The central processing system 8 is used to release electrical signals to control the main reaction chamber cover plate 2, the resistance wire 6 and the electromagnetic conversion chamber 5 in sequence. The coil of the main reaction chamber cover plate 2 is energized, and the ferromagnet attracts the heterogeneous material storage chamber 3. When the storage chamber 3 is filled with materials, the power is stopped and the chamber sinks. The electromagnetic reaction chamber 5 is energized, the main reaction chamber magnet 4-2 rotates, and the heterogeneous material storage chamber 3 rotates rapidly at the same time, the material flows out from the bottom, the resistance wire is energized, and the reaction is accelerated. After the mixing is completed, the electromagnetic reaction chamber 5 stops energizing, the main reaction chamber cover plate 2 is energized, and the lightweight balance rod 3-1 attracts the magnet 4-2. The main reaction chamber cover plate 2 attracts the heterogeneous material storage chamber 3 for recovery. The central processing system 8 is connected to the equipment through the wiring port 7.
[0049] The specific process of an ultra-high strength polyimide-based composite foam integrated molding device and method with electromagnetic wave absorption function includes the following steps:
[0050] Step 1: Pretreatment of reaction raw materials, take 85g 3,3',4,4'-dibenzophenone tetracarboxylic acid dianhydride and dissolve it in 90g dimethylformamide organic solvent, heat and stir, and add 8.5g methanol to the solution in batches within five minutes. Then add 1.0g triethanolamine and heat and stir for two hours. Finally, add 1.0g of catalyst stannous isooctanoate, 9.0g of foaming agent (AK8805), and 15g of deionized water. Add 0.3g and 1.5g of multi-walled carbon nanotubes and carbonyl iron powder to the obtained mixture, record it as A material, and take 20g of A material as the main reaction chamber raw material. In addition, take 12g of polyphenyl polymethylene polyisocyanate, 2g of diphenylmethane diisocyanate, heat and mix, add 0.15g and 1.4g of multi-walled carbon nanotubes and carbonyl iron powder, record it as B material, this is the raw material of the heterogeneous material storage chamber.
[0051] Step 2: Pour material A into the main reaction chamber, the central processing system energizes the main reaction chamber cover to attract the foreign material storage chamber, fills the foreign material storage chamber with material B, and closes the storage chamber cover.
[0052] Step 3: The central processing system energizes the electromagnetic conversion chamber, and the motor rotates to drive the magnets to rotate. The resistance wire is energized, and the main chamber is heated.
[0053] Step 4: The cover of the main reaction chamber stops being powered, and the heterogeneous material storage chamber drops due to gravity, controlling the current intensity of the electromagnetic conversion chamber and increasing the magnetic field intensity. The heterogeneous material storage chamber rotates rapidly under the action of the magnetic field, driving the funnel baffle at the bottom of the storage chamber to open, and material B quickly flows into the vortex and mixes quickly with material A. Open the gas flow cabinet, introduce inert gas, and adjust the gas pressure according to the reaction situation. The initial gas pressure is 0.1MPa.
[0054] Step 5: Material B in the heterogeneous material storage chamber decreases, the storage chamber rises under pressure, the balance bar falls into the funnel mouth to prevent material backflow, and the balance bar falls into the bottom of the main reaction chamber to attract the magnet.
[0055] Step 6: Stop energizing the electromagnetic conversion chamber and the resistance wire, and energize the main reaction chamber cover. Attract the heterogeneous material storage chamber to the top, and the lightweight balance rod absorbs the magnet to take out the reaction material. Control the airflow pressure and let it stand for foaming.
[0056] Step 7: After the foaming is completed, connect the airflow port of the outer tank to a vacuum pump to evacuate the gas in the foam to form open cells. After the pressure is released, open the main reaction chamber to demould and obtain the sample.
[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.
Claims
1. An ultra-high strength polyimide-based composite foam integrated molding equipment and method with electromagnetic wave absorption function: including an outer tank, a main reaction chamber cover, a heterogeneous material storage chamber, a main reaction chamber, an electromagnetic conversion chamber, a temperature control system, a wiring port, and a central processing system. The outer tank and the tank top cover are connected to the tank body by a clamp, one port of the cover is connected to an air flow pressure display to monitor the air pressure in the tank in real time, and the other port is connected to a gas flow cabinet to control the air pressure in the tank. The main reaction chamber cover is made of a ring-shaped electromagnet with a coil wrapped around it. There are array holes on the surface of the electromagnet to keep the air pressure inside and outside the reaction chamber consistent. The inner ring generates a magnetic field to adsorb the foreign material storage cavity when power is turned on. The ring design makes it easy to add materials to the storage cavity at any time after the cover is closed and to expose the lightweight balance rod. The heterogeneous material storage chamber is made of a light magnetic material, with a hole at the axis position and a light balance rod. The rod diameter is slightly smaller than the axis hole diameter, so that the light rod can move up and down in the storage chamber without excessive tilting and maintain overall stability when the storage chamber rotates. A flat cylindrical round cap is formed on the upper part of the light rod, and the cap diameter is larger than the axis hole diameter to prevent the light rod from slipping out. A small magnet is fixed at the bottom of the light rod, which adsorbs the magnetic stirring bar at the bottom when the material in the storage chamber flows out. The funnel-shaped design at the bottom of the storage chamber facilitates the outflow of viscous materials and reduces adhesion. A ring bearing is fixed at the mouth of the funnel, and four rotating blades are arranged outside the bearing. Under the control of the controllable super-strong magnetic field at the bottom, the bearing drives the blades to achieve high-speed rotation and stirring of materials. The main reaction chamber is made of transparent organic glass and is detachable as a whole. In the pre-preparation stage, a polyethylene film can be coated on its surface to prevent material adhesion and facilitate product foam demoulding. Four magnetic stirrers are arranged in the chamber. The electromagnetic conversion chamber is composed of a motor and a magnet substrate, on which permanent magnets, coil ferromagnets, Hall elements, etc. are arranged, and the magnetic field strength of the ferromagnets can be adjusted by inputting current. In addition, when the circuit is turned on, the motor rotates, and the changing magnetic field drives the magnetons in the main reaction chamber to rotate, thereby generating a magnetic stirring effect. The temperature control system is composed of a resistance heating wire, and the appropriate temperature is set according to different material viscosities and reaction temperatures. The central processing system is used to release electrical signals to control the main reaction chamber cover, the resistance wire and the electromagnetic conversion chamber in sequence. The coil of the main reaction chamber cover is energized, and the ferromagnet attracts the heterogeneous material storage chamber. When the storage chamber is filled with materials, the power is stopped and the chamber sinks. The electromagnetic reaction chamber is energized, the main reaction chamber magnet rotates, the heterogeneous material storage chamber rotates rapidly, the material flows out from the bottom, the resistance wire is energized, and the reaction is accelerated. After the mixing is completed, the electromagnetic reaction chamber stops energizing, the main reaction chamber cover is energized, and the lightweight rod attracts the magnet. The main reaction chamber cover attracts the heterogeneous material storage chamber for recovery. The central processing system is connected to the equipment through a wiring port.
2. The ultra-high strength polyimide-based composite foam integrated molding device and method with electromagnetic wave absorption function according to claim 1 is characterized in that: The outer tank body is made of transparent organic glass, which is convenient for observing the reaction speed in the tank. The tank body and the cover plate are connected by a polytetrafluoroethylene rubber sealing ring and coated with high vacuum silicone grease to ensure sealing. In addition, the air flow port is detachable and can be connected to a vacuum pump to achieve low air pressure in the tank after the air supply is completed.
3. The ultra-high strength polyimide-based composite foam integrated molding device and method with electromagnetic wave absorption function according to claim 1 is characterized in that: The top of the heterogeneous material storage chamber is provided with two raised flip-top cylindrical pipe openings, through which the material is poured into the storage chamber, and the flip-top is closed after it is filled. The bottom funnel opening is also provided with a partition, which opens when the bearing rotates, and the material flows out and mixes with the main reaction material.
4. According to claim 1, a kind of ultra-high strength polyimide-based composite foam integrated molding equipment and method with electromagnetic wave absorption function, wherein the raw materials and content used are specifically: 3,3',4,4'-dibenzophenone tetracarboxylic dianhydride (85g), dimethylformamide organic solvent (90g), methanol (8.5g), triethanolamine (1.0g), catalyst stannous isooctanoate (1.0g), foaming agent (AK8805) (9.0g), deionized water (15g), after mixing the materials, take 15g and add multi-walled carbon nanotubes (0.3g), spherical carbonyl iron powder (1.5g). The above-mentioned material mixture is recorded as material A and placed in the main reaction chamber. In addition, polyphenyl polymethylene polyisocyanate (12 g) and diphenylmethane diisocyanate (2 g) were mixed, multi-walled carbon nanotubes (0.15 g) and spherical carbonyl iron powder (1.4 g) were added, and the mixture was recorded as material B and placed in the heterogeneous material storage chamber.
5. An integrated molding device and method for ultra-high strength polyimide-based composite foam with electromagnetic wave absorption function, characterized in that Use the following steps: Step 1: Select two suitable foaming components, pre-treat each component, add suitable fillers and stir evenly, and place them in the main reaction chamber or the heterogeneous material storage chamber according to the proportion. The volume of the main reaction chamber material accounts for about 80% of the total chamber volume. Step 2: The main reaction chamber cover is powered on to generate a magnetic field to firmly hold the heterogeneous material storage chamber, open the heterogeneous material storage chamber cover, add materials until the chamber is full, and close the cover. Step 3: The electromagnetic conversion chamber is powered on, the motor rotates to drive the magnet to rotate. The resistance wire is powered on, and the main chamber is heated. Step 4: The cover of the main reaction chamber stops being powered, and the heterogeneous material storage chamber drops due to gravity, controlling the current intensity of the electromagnetic conversion chamber and increasing the magnetic field intensity. The heterogeneous material storage chamber rotates rapidly under the action of the magnetic field, driving the funnel baffle at the bottom of the storage chamber to open, and the heterogeneous material quickly flows into the vortex and mixes quickly with the material in the main reaction chamber. Open the gas flow cabinet, introduce inert gas, and adjust the gas pressure according to the reaction situation. Step 5: The material in the heterogeneous material storage chamber decreases, the storage chamber rises under the action of the material pressure, the balance rod falls into the funnel mouth to prevent the material from flowing back, and the balance rod falls into the bottom of the main reaction chamber to attract the magnet. Step 6: Stop energizing the electromagnetic conversion chamber and the resistance wire, and energize the main reaction chamber cover. Attract the heterogeneous material storage chamber to the top, and the lightweight balance rod absorbs the magnet to take out the reaction material. Control the airflow pressure and let it stand for foaming. Step 7: After the foaming is completed, connect the airflow port of the outer tank to a vacuum pump to evacuate the gas in the foam to form open cells. After the pressure is released, open the main reaction chamber to demould and obtain the sample.