A segmented thread type drum structure DBD powder coating device

Abstract

The application discloses a DBD powder coating device with a segmented thread type roller structure, and the inlet and outlet gas plugs of a cylindrical reactor are detachably and tightly fixed at the two ends of a roller; the inlet gas plug is integrated with an inlet gas rotating shaft in an epoxy material structure; the hollow inlet gas rotating shaft realizes the transmission of gas to the reactor in sequence through the inlet gas rotating shaft and the inlet gas plug; three different thread protrusions are arranged on the inner wall of the reactor; a high-voltage electrode rod is fixed at the central axis position of the roller; the outer wall of the roller is wrapped with a metal mesh as a ground electrode; the outlet gas plug is connected with a rotating shaft so as to realize the rotation of the reactor driven by a motor; the surface of the rotating shaft at the inlet and outlet ends of the roller is sleeved with a through-hole conductive slip ring; and the high voltage is sequentially transmitted to the rotor of the through-hole conductive slip ring at the outlet end and the power supply wire hole arranged on the outlet plug, so as to realize the connection of the high-voltage electrode rod and an excitation power supply circuit. The application can realize the continuous rolling and stirring of the powder to be treated while the plasma treatment is carried out, and can significantly improve the uniformity of the treatment effect.

Description

Technical Field

[0001] This invention relates to the field of low-pressure plasma technology, specifically to a segmented threaded roller structure DBD powder coating device. Background Technology

[0002] With the rapid development of the electronics industry, epoxy resin encapsulation materials have been widely used in the encapsulation of electronic components due to their excellent electrical insulation and mechanical properties. However, the inherent low thermal conductivity and poor heat resistance of polymer materials limit their application in scenarios with high requirements for heat dissipation and thermal expansion. Therefore, how to improve the thermal conductivity of epoxy resin while maintaining good insulation properties has become a problem to be solved. A common solution is to prepare resin-based thermally conductive and insulating composite materials by filling the resin matrix with high thermal conductivity fillers. Compared with intrinsically high thermal conductivity polymers, the preparation method of filled thermally conductive composite materials is simpler and easier to mass-produce. However, when filling powder fillers into the polymer matrix, the large difference in polarity and the lack of chemical bonds between the two lead to interfacial incompatibility and introduce a large number of interfacial defects. Therefore, it is necessary to coat and modify the powder fillers to eliminate interfacial polarity differences and enhance interfacial adhesion.

[0003] Traditional powder coating methods include physical coating and chemical coating. Physical coating is simple to operate and suitable for powder particles of various shapes and materials, but the interfacial bonding between the coating layer and the matrix is ​​weak, making it prone to peeling. Chemical coating can control the thickness of the coating layer by adjusting the chemical reaction conditions and can form a more stable bond, but it generates waste liquid that can pollute the environment, requiring strict control of reaction conditions.

[0004] In recent years, low-temperature plasma technology has provided a new approach to solving the aforementioned problems. Low-temperature plasma modification of material surfaces can stimulate surface activity and generate a large number of free radicals in a short time. By using an ionizing medium, the desired polymer groups are implanted into the powder surface, achieving a tight bond between the coating layer and the matrix, improving the adhesion and stability of the coating layer. Using low-temperature plasma to treat powder fillers results in strong interfacial bonding between the coating layer and the matrix, eliminating the need for cumbersome drying steps and producing no waste liquid pollution, making it environmentally friendly and non-toxic. However, the uniformity of the coating layer in powders modified by low-temperature plasma technology is difficult to control, leading to problems such as powder agglomeration and unstable performance.

[0005] Existing technology publication CN 114316509 A proposes a method combining coupling agent modification and physical coating modification via mechanical mixing. However, this method is complex, requires strict control over the weight ratio of raw materials, and involves cumbersome subsequent absorbent powder processing steps. Furthermore, the physical modification of the absorbent powder requires high temperatures. Publication CN104028749A uses a chemical coating method to insulate metal magnetic powder. This process involves numerous chemical reactions and material transformations, making it complex and generating wastewater that pollutes the environment. Publication CN103247803A employs a coaxial DBD powder coating device with a high discharge initiation voltage, low powder processing efficiency, uneven coating layer, and requires a low-pressure environment. Existing technology application CN202211159946.3 discloses a roller-type DBD insulating ceramic powder coating device, which uses a roller device as a plasma reactor to coat the surface of nanoparticles, effectively improving the dielectric energy storage density. In practice, it was found that the increase in thermal conductivity of the composite material formed by the nanoparticles and epoxy groups after being processed by this device was uncontrollable. This is most likely because the powder coating was uneven, which led to an unstable effect in eliminating the interfacial polarity difference of the material.

[0006] Therefore, in order to achieve uniform coating of powder, the DBD powder coating device needs to be improved accordingly. Summary of the Invention

[0007] 1. The technical problem to be solved: To address the aforementioned technical problems, this invention provides a segmented threaded roller structure DBD powder coating device. By generating a plasma ionization medium, specific groups are introduced onto the powder surface, improving the interfacial affinity between the powder and the epoxy matrix, resulting in a tighter bond between the two, reducing interfacial defects, lowering phonon scattering, and ensuring uniform powder coating through reactor rotation, thereby achieving the goal of improving the performance of composite materials.

[0008] 2. Technical Solution: A segmented threaded drum structure DBD powder coating device is characterized by comprising a gas source, a drum-shaped reactor, a rotating shaft, a rotating motor, a through-hole conductive slip ring, an excitation power supply, and a reaction frame. The reactor includes a cylindrical drum, an inlet plug, an outlet plug, a metal mesh ground electrode, and a high-voltage electrode rod. The inlet plug and outlet plug are detachably sealed and fixed to both ends of the drum. The inlet plug and its connected inlet pipe are an integral structure. The inner wall of the reactor is provided with three threaded protrusions along the inlet direction. The first thread extends in the same direction as the inlet direction, the second thread extends in the opposite direction, and the third thread extends in the opposite direction. The widths of the first and third thread sections are the same, and all are greater than the width of the second thread section. A high-voltage electrode support for fixing the high-voltage electrode rod is provided at the inlet end of the cylindrical drum. The other end of the high-voltage electrode rod is fixed to the center hole of the outlet plug. The high-voltage electrode rod is located at the central axis of the drum. The outlet plug is provided with an outlet that connects the inner cavity of the reactor to the outside. The outer wall of the drum is wrapped with a metal mesh as a ground electrode; the outer end of the outlet plug is fixedly connected to a rotating shaft; the rotating shaft is connected to a rotary motor to drive the reactor to rotate simultaneously; the surface of the inlet pipe and the rotating shaft is fitted with a through-hole conductive slip ring; the inlet pipe, the through-hole conductive slip ring and the reactor are coaxial; when the motor rotates, the rotating shaft drives the rotor inside the through-hole conductive slip ring to rotate; the stator of the through-hole conductive slip ring is fixedly connected to the reaction frame; After the excitation power supply is connected to the stator terminal of the through-hole conductive slip ring, the high-voltage electrode rod is connected to the high-voltage electrode circuit of the excitation power supply through the rotor and the through-hole wire provided in the outlet plug.

[0009] Furthermore, this device uses a bubbling method to evaporate the liquid medium, mix it with a working gas at a certain flow rate, and carry the medium out as a gas from liquid to gas. Finally, the gas enters the mixing chamber and is sent into the reactor by the inlet rotating shaft.

[0010] Furthermore, the metal mesh ground electrode is connected to the ground electrode of the excitation power supply in sequence through the through-hole conductive slip ring rotor and stator terminal at the air inlet end.

[0011] Furthermore, the roller is a quartz glass roller; the high-voltage electrode rod is a tungsten rod; and the metal mesh of the ground electrode is a stainless steel mesh.

[0012] Furthermore, the working gas is argon, nitrogen, or ammonia, and the reaction medium is planned to be HMDSO or PDMS.

[0013] Furthermore, the length of the roller is 90~100mm, the outer diameter is 13~14mm, the inner diameter is 12mm, and the wall thickness is 1~2mm; the pitch of the three threads is equal, all being 5mm; the length of the metal mesh ground electrode is 65~75mm; and the length of the high-voltage electrode rod is 95~105mm.

[0014] Furthermore, it also includes a current coil, a high-voltage probe, and an oscilloscope; the current coil, which is used for current blocking and frequency modulation, is connected to the through-hole conductive slip ring circuit; the high-voltage probe is connected to the through-hole conductive slip ring circuit to detect the high-voltage signal in the circuit and display it on the oscilloscope.

[0015] 3. Beneficial effects: (1) The present invention provides a segmented threaded roller structure DBD powder coating device. The reactor adopts a roller structure to place the powder to be processed in the cavity of the roller. A tungsten rod located in the middle position is used as a high voltage positive electrode, and a metal mesh ground electrode is wrapped around the outer end of the roller. Compared with surface DBD, the bulk DBD of this application has advantages such as a more uniform discharge area, higher energy density and better controllability.

[0016] (2) The present invention provides a segmented threaded roller structure DBD powder coating device. The roller structure adopts a regular segmented thread. During the rotation of the reactor, the powder is conveyed by the thread and moves in the opposite direction to the airflow, thereby solving the problem of powder accumulation on the air outlet side of the roller. This improves the powder processing efficiency and further enhances the uniformity of powder coating.

[0017] (3) The present invention provides a segmented threaded roller structure DBD powder coating device, in which through-hole conductive slip rings are respectively set at the two ends of the outer end of the roller, so as to realize the transmission of voltage and the rotation of the reactor at the same time; at the same time, the stator is fixed on the reaction frame, which can effectively prevent the reactor from flying out due to excessive speed during rotation; the rotor rotates coaxially with the reactor, and the wire on the side of the rotor facing the reactor also rotates coaxially with the high voltage or ground electrode of the reactor, and the wire in the opposite direction can be fixed on the stator and connected to the high voltage or ground electrode of the excitation power supply without entanglement.

[0018] (4) The present invention provides a segmented threaded roller structure DBD powder coating device. When the device is working, by introducing gas at a certain flow rate, the cylindrical shape of the roller will result in a relatively low pressure drop. The effect can be achieved without a large wall thickness, thereby avoiding the increase in reactor cost due to increased wall thickness. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a segmented threaded roller structure DBD powder coating device according to the present invention; Figure 2 This is a schematic diagram of the overall structure of the drum-shaped reactor in this invention; Figure 3 This is a schematic diagram of the conductive via slip ring in this invention; Figure 4 This is a schematic diagram of the high-voltage electrode support in this invention; Figure 5This is a schematic diagram of the reactor and its inner wall threads in this invention; Figure 6 This is a schematic diagram of the reactor and the metal ground electrode in this invention; Figure 7 This is a schematic diagram of the air outlet plug in this invention; Figure 8 This is a schematic diagram showing the connection of the high-voltage electrode rod in the reactor of the present invention; Figure 9 This is a flowchart of a specific embodiment.

[0020] Reference numerals: 1. Through-hole conductive slip ring; 101. Rotor of through-hole conductive slip ring; 102. Terminal for transmitting electrical signals of through-hole conductive slip ring; 103. Stator of through-hole conductive slip ring; 2. Inlet plug; 3. High-voltage electrode support; 4. Threaded protrusion; 401. Locking thread between inlet plug or outlet plug and reactor; 402. First thread; 403. Second thread; 404. Third thread; 5. Metal mesh ground electrode; 6. High-voltage electrode rod; 7. Reactor; 8. Outlet plug; 801. Fixing point between outlet plug and high-voltage electric shock rod; 802. Outlet port; 803. Electrical wire hole of outlet plug; 804. Rotary shaft; 9. Rotary motor; 10. Mixing chamber; 11. Check valve; 12. Flow meter; 13. High-pressure gas cylinder; 14. Bubbling device; 15. Current coil; 16. High-voltage probe; 17. Excitation power supply; 18. Oscilloscope; 19. Nanopowder. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings.

[0022] As attached Figure 1 To be continued Figure 8 As shown, a segmented threaded roller structure DBD powder coating device is characterized by including a gas source, a roller-shaped reactor 7, a rotating shaft 804, a rotating motor 9, a through-hole conductive slip ring 1, an excitation power supply 17, and a reaction frame. The reactor includes a cylindrical drum, an inlet plug 2, an outlet plug 8, a metal mesh ground electrode 5, and a high-voltage electrode rod 6. The inlet plug and outlet plug are detachably sealed and fixed to both ends of the drum. The inlet plug and its connected inlet pipe are integral structures. The inner wall of the reactor is provided with three threaded protrusions 4 along the inlet direction. The first thread 402 extends in the same direction as the inlet direction, the second thread 403 extends in the opposite direction to the inlet direction, and the third thread 404 extends in the opposite direction to the inlet direction. The widths of the first and third threads are the same, both greater than the width of the second thread. A high-voltage electrode bracket 3 for fixing the high-voltage electrode rod is provided at the inlet end of the cylindrical drum. The other end of the high-voltage electrode rod is fixed to the center hole of the outlet plug. The high-voltage electrode rod is located at the central axis of the drum. The outlet plug is provided with an outlet 802 that connects the inner cavity of the reactor to the outside. The outer wall of the drum is wrapped with a metal mesh as a ground electrode; the outer end of the outlet plug is fixedly connected to a rotating shaft; the rotating shaft is connected to a rotary motor to drive the reactor to rotate simultaneously; the surface of the inlet pipe and the rotating shaft is fitted with a through-hole conductive slip ring; the inlet pipe, the through-hole conductive slip ring and the reactor are coaxial; when the motor rotates, the rotating shaft drives the rotor inside the through-hole conductive slip ring to rotate; the stator of the through-hole conductive slip ring is fixedly connected to the reaction frame; The excitation power supply is connected to the stator 103 terminal 102 of the through-hole conductive slip ring, and then the high-voltage electrode rod is connected to the high-voltage electrode circuit of the excitation power supply through the rotor 101 and the through-hole 803 of the outlet plug.

[0023] As attached Figure 5 As shown, the threaded protrusions in the reactor include: a locking thread 401 between the inlet or outlet plug and the reactor; a first thread 402; a second thread 403; and a third thread 404. (See attached diagram.) Figure 6 In the middle, 801 is the fixing point between the vent plug and the high-voltage electric shock rod.

[0024] Furthermore, this device uses a bubbling method to evaporate the liquid medium, mix it with a working gas at a certain flow rate, and carry the medium out as a gas from liquid to gas. Finally, the gas enters the mixing chamber and is sent into the reactor by the inlet rotating shaft.

[0025] Furthermore, the metal mesh ground electrode is connected to the ground electrode of the excitation power supply in sequence through the through-hole conductive slip ring rotor and stator terminal at the air inlet end.

[0026] Furthermore, the roller is a quartz glass roller; the high-voltage electrode rod is a tungsten rod; and the metal mesh of the ground electrode is a stainless steel mesh.

[0027] Furthermore, the working gas is argon, nitrogen, or ammonia, and the reaction medium is planned to be HMDSO or PDMS.

[0028] Furthermore, the length of the roller is 90~100mm, the outer diameter is 13~14mm, the inner diameter is 12mm, and the wall thickness is 1~2mm; the pitch of the three threads is equal, all being 5mm; the length of the metal mesh ground electrode is 65~75mm; and the length of the high-voltage electrode rod is 95~105mm.

[0029] Furthermore, it also includes a current coil 15, a high-voltage probe 16, and an oscilloscope 18; the current coil, which is used for current blocking and frequency modulation, is connected to the through-hole conductive slip ring circuit; the high-voltage probe is connected to the through-hole conductive slip ring circuit to detect the high-voltage signal in the circuit and display it through the oscilloscope. Specific implementation examples: As attached Figure 9The flowchart shown illustrates the process using this method. This method includes a gas supply stage, a power supply debugging stage, and a product collection stage. In the gas supply stage, high-purity Ar is used as the working gas in this embodiment, and the gas flow rate is monitored in real time using a flow meter 12. Before the device operates, the nanoparticles 19 to be processed are added to the drum reactor. Then, the sealing plug and the reactor are connected to prevent powder leakage. Next, the entire device is connected, and the high-pressure gas cylinder 13 and the bubbling device 14 are opened. Ar and the reaction medium are then introduced into the reaction device through the mixing chamber 10.

[0031] In this step, the gas flow rate is first adjusted using one-way valve 11 until the powder particles are evenly distributed within the drum reactor, and then the flow rate is kept constant. Next, the power supply is turned on and the power parameters are adjusted until a large-volume, high-intensity, and stable discharge plasma is generated. Once this state is achieved, the power parameters must be kept constant to stably discharge and process the powder particles. After processing, the power supply is turned off to end the reaction, and then the gas intake is stopped; only then is the entire reaction process considered complete.

[0032] Although the present invention has been disclosed above with reference to preferred embodiments, these are not intended to limit the invention. Any person skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be defined by the scope of the claims of this application.

Claims

1. A segmented threaded roller structure DBD powder coating device, characterized in that: It includes a gas source, a drum-shaped reactor, a rotating shaft, a rotating motor, a through-hole conductive slip ring, an excitation power supply, and a reaction rack; The reactor includes a drum, an inlet plug, an outlet plug, a metal mesh ground electrode, and a high-voltage electrode rod. The inlet plug and outlet plug are detachably and sealed to both ends of the drum. The inlet plug and its connected inlet pipe are an integral structure. The inner wall of the reactor has three threaded protrusions along the inlet direction. The first thread extends in the same direction as the inlet direction, the second thread extends in the opposite direction, and the third thread extends in the opposite direction. The widths of the first and third threads are the same, both greater than the width of the second thread. A high-voltage electrode support for fixing the high-voltage electrode rod is provided at the inlet end of the drum. The other end of the high-voltage electrode rod is fixed to the center hole of the outlet plug. The high-voltage electrode rod is located at the central axis of the drum. The outlet plug has an outlet that connects the inner cavity of the reactor to the outside. The outer wall of the drum is wrapped with a metal mesh as a ground electrode; the outer end of the outlet plug is fixedly connected to a rotating shaft; the rotating shaft is connected to a rotary motor to drive the reactor to rotate simultaneously; the surface of the inlet pipe and the rotating shaft is fitted with a through-hole conductive slip ring; the inlet pipe, the through-hole conductive slip ring and the reactor are coaxial; when the motor rotates, the rotating shaft drives the rotor inside the through-hole conductive slip ring to rotate; the stator of the through-hole conductive slip ring is fixedly connected to the reaction frame; After the excitation power supply is connected to the stator terminal of the through-hole conductive slip ring, the high voltage electrode rod is connected to the high voltage electrode circuit of the excitation power supply through the rotor and the through-wire hole set in the outlet plug. The drum is a quartz glass drum; the high voltage electrode rod is a tungsten rod; and the metal mesh of the ground electrode is a stainless steel mesh. This device uses a bubbling method to evaporate the liquid medium, mix it with the working gas, and carry the medium out as a gas from liquid to gas. Finally, the gas enters the mixing chamber and is sent into the reactor by the inlet rotating shaft.

2. The DBD powder coating device with a segmented threaded roller structure according to claim 1, characterized in that: The metal mesh ground electrode is connected to the ground electrode of the excitation power supply in sequence through the through-hole conductive slip ring rotor and stator terminal at the air inlet end.

3. The DBD powder coating device with a segmented threaded roller structure according to claim 1, characterized in that: The working gas is argon, nitrogen, or ammonia, and the reaction medium is HMDSO or PDMS.

4. The DBD powder coating device with a segmented threaded roller structure according to claim 1, characterized in that: The length of the roller is 90~100mm, the outer diameter is 13~14mm, the inner diameter is 12mm, and the wall thickness is 1~2mm; the pitch of the three threads is equal, all being 5mm; the length of the metal mesh ground electrode is 65~75mm; and the length of the high-voltage electrode rod is 95~105mm.

5. The DBD powder coating device with a segmented threaded roller structure according to claim 1, characterized in that: It also includes a current coil, a high-voltage probe, and an oscilloscope; the current coil, which is used for current blocking and frequency modulation, is connected to the through-hole conductive slip ring circuit; the high-voltage probe is connected to the through-hole conductive slip ring circuit to detect the high-voltage signal in the circuit and display it on the oscilloscope.

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