Coplanar dielectric barrier discharge device for surface modification of insulating material

Abstract

The invention discloses a coplanar dielectric barrier discharge device for surface modification of an insulating material, and the device comprises a voltage regulator which is used for converting AC commercial power into AC voltage with adjustable voltage amplitude; the plasma power supply is used for converting the alternating voltage output by the voltage regulator into alternating voltage with adjustable amplitude and fixed center frequency; the coplanar dielectric barrier discharge load is used for generating atmospheric pressure air low-temperature plasma under the action of the plasma power supply; the mechanical supporting structure is used for supporting and moving the coplanar dielectric barrier discharge load; and the data acquisition and analysis system is used for measuring and recording the actual working condition of the coplanar dielectric barrier discharge load and executing a protection action when an abnormal working condition is found. According to the invention, macroscopically uniform low-temperature plasmas can be generated in atmospheric pressure air, modification treatment of a large-area and flat-surface insulating material is realized, and the problems of high cost, small discharge area, poor uniformity and the like of an existing plasma surface modification technology are solved.

Description

Technical Field

[0001] The invention relates to low-temperature plasma generation technology, and in particular to a device for generating atmospheric pressure air low-temperature plasma by using coplanar dielectric barrier discharge, belonging to the field of plasma technology. Background Art

[0002] In recent years, material surface modification has become a research hotspot in plasma applications. Compared with traditional wet surface modification, low-temperature plasma surface modification has the advantages of environmental protection, low energy consumption, and little damage to the material surface. Among them, the surface modification of insulating materials using low-temperature plasma generated by dielectric barrier discharge is a major approach suitable for industrial applications. In terms of surface research, the macroscopic uniformity of plasma is a key factor affecting the surface modification effect of insulating materials. Therefore, how to use atmospheric pressure air dielectric barrier discharge to generate macroscopically uniform low-temperature plasma in industrial application scenarios is a key issue worthy of attention. Most of the existing plasma jet devices and other solutions have problems such as small discharge area, poor uniformity, and the need for carrier gas and its flow control, and are not suitable for large-area, flat-surface insulating material modification. Therefore, studying a dielectric barrier discharge device for surface modification of insulating materials has important practical application value for improving specific surface properties of insulating materials (such as wettability, water absorption, adhesion, and conductivity, etc.), and has an important theoretical support role in the rational design of discharge devices to improve the macroscopic uniformity of the low-temperature plasma they produce. Summary of the invention

[0003] The purpose of the present invention is to address the shortcomings of the above-mentioned background technology and provide a coplanar dielectric barrier discharge device for surface modification of insulating materials, which can generate macroscopically uniform low-temperature plasma in atmospheric pressure air to achieve the purpose of modifying insulating materials with a large area and a smooth surface, and solve the problems of high cost, small discharge area, and poor uniformity of existing plasma surface modification technologies.

[0004] The present invention adopts the following technical solutions to achieve the above-mentioned invention object: A coplanar dielectric barrier discharge device for surface modification of insulating materials comprises: a voltage regulator, a plasma power supply, a coplanar dielectric barrier discharge load, a mechanical support structure and a data acquisition and analysis system; wherein the voltage regulator is used to convert 220V AC mains into an AC voltage with adjustable voltage amplitude; the plasma power supply is used to convert the AC voltage output by the voltage regulator into an AC voltage with adjustable amplitude (0-30kV) and fixed center frequency (10kHz); the coplanar dielectric barrier discharge load is used to generate atmospheric pressure air low-temperature plasma under the action of the plasma power supply; the mechanical support structure is used to support and move the coplanar dielectric barrier discharge load; the data acquisition and analysis system is used to measure and record the actual working condition of the coplanar dielectric barrier discharge load, and execute a protection action to cut off the 220V AC mains when an abnormal working condition is found.

[0005] In a coplanar dielectric barrier discharge device for surface modification of insulating materials, the coplanar dielectric barrier discharge load is a comb-shaped electrode structure, and the high and low voltage electrodes are arranged crosswise to form eight pairs of discharge electrodes. Among them, the electrode material is 35μm thick copper foil, the electrode width is 2mm; the dielectric material is FR-4, the thickness is 0.4mm; the electrodes are sealed with 2mm thick silicone rubber K704-L, so that the discharge occurs on the other side of the dielectric.

[0006] In a coplanar dielectric barrier discharge device for surface modification of insulating materials, the mechanical support structure has a height-adjustable lifting platform and a movable support track. The lifting platform can adjust the distance between the coplanar dielectric barrier load attached thereto and the surface of the insulating material to be processed; the movable support track is used to adjust the position of the lifting platform, thereby adjusting the processing area of ​​the coplanar dielectric barrier discharge load on the insulating material.

[0007] In a coplanar dielectric barrier discharge device for surface modification of insulating materials, the data acquisition and analysis system includes a current transformer, an oscilloscope, an infrared thermal imager, and a computer. The current transformer collects the output current of the plasma power supply and returns the data to the oscilloscope; the infrared thermal imager is used to measure the surface temperature of the insulating material when the device is working; the computer is used to analyze the output current and temperature, and issue a protection instruction in case of overcurrent or overtemperature to cut off the 220V AC mains.

[0008] As a further optimization scheme for a coplanar dielectric barrier discharge device used for surface modification of insulating materials, considering that the surface temperature of the coplanar dielectric barrier discharge load will increase to a certain extent during discharge, in order to minimize the deterioration of the modification effect caused by the increase in surface temperature, an aluminum heat sink can be attached to the silicone rubber surface of the coplanar dielectric barrier discharge load to increase the heat dissipation contact area, and a 24V DC cooling fan can be installed to release the heat output from the heat sink.

[0009] The present invention adopts the above technical solution and has the following beneficial effects: (1) The device proposed in the present invention utilizes the advantages of coplanar dielectric barrier discharge, such as simple structure, low cost, good macroscopic uniformity, and no need for carrier gas, to achieve surface treatment of insulating materials with large area and flat surface through a mechanical support structure, thus solving the problems of small discharge area, poor uniformity, and the need for carrier gas and its flow control in existing plasma surface treatment devices, and providing a new device for improving specific surface properties of insulating materials (such as wettability, water absorption, adhesion, and conductivity, etc.).

[0010] (2) The coplanar dielectric barrier discharge load in the device of the present invention can select parameters such as electrode material, dielectric material, geometric structure and size according to actual conditions. Therefore, the device has good applicability to various insulating materials to be treated. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The present invention is a schematic structural diagram of a coplanar dielectric barrier discharge device for surface modification of insulating materials shown in an embodiment of the present invention.

[0012] Figure 2 It is a specific structural diagram of a coplanar dielectric barrier discharge load shown in an embodiment of the present invention.

[0013] Figure 3 It is a schematic diagram of the coplanar dielectric barrier discharge electrode structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0014] The present invention is further described below in conjunction with the accompanying drawings.

[0015] Description of reference numerals: 1——Voltage regulator 2——Plasma power supply 3——Coplanar dielectric barrier discharge load 4 - Mechanical support structure 5——Data acquisition and analysis system 6——Current transformer 7. Thermal imaging camera 8——Oscilloscope 9. Computer 10——Insulation materials to be treated 11 - Electrodes 12 - Medium 13——Silicone rubber The technical solution of the invention is described in detail below with reference to the accompanying drawings.

[0016] In a specific embodiment of the present invention, there is provided a Figure 1The coplanar dielectric barrier discharge device for surface modification of insulating materials shown in the figure comprises a voltage regulator 1, a plasma power supply 2, a coplanar dielectric barrier discharge load 3, a mechanical support structure 4 and a data acquisition and analysis system 5. The voltage regulator 1 is used to convert 220V AC mains power into an AC voltage with adjustable voltage amplitude. The plasma power supply 2 is used to convert the AC voltage output by the voltage regulator 1 into an AC voltage with adjustable amplitude (0-30kV) and fixed center frequency (10kHz). The coplanar dielectric barrier discharge load 3 is used to generate atmospheric pressure air low-temperature plasma under the action of the plasma power supply 2. The mechanical support structure 4 is used to support and move the coplanar dielectric barrier discharge load 3; the data acquisition and analysis system 5 is used to measure and record the actual working conditions of the coplanar dielectric barrier discharge load 3, and to perform protection actions and cut off the 220V AC mains power when abnormal working conditions are found.

[0017] like Figure 1 As shown, the data acquisition and analysis system 5 includes: a current transformer 6, an infrared thermal imager 7, an oscilloscope 8 and a computer 9. The current transformer 6 is used to collect the output current of the plasma power supply 2 and return the data to the oscilloscope 8; the infrared thermal imager 7 is used to measure the surface temperature of the insulating material 10 when the device is working; the computer 9 is used to analyze the output current and temperature, and issue a protection instruction in case of overcurrent or overtemperature to cut off the 220V AC mains.

[0018] like Figure 2 As shown, the coplanar dielectric barrier discharge load 3 includes: an electrode 11, a dielectric 12 and a silicone rubber 13. The electrode 11 is a comb structure, and the material is a copper foil with a thickness of 35 μm and a width of 2 mm. The electrodes are arranged crosswise to form eight pairs of discharge electrodes, one end of which is connected to the output side of the plasma power supply 2, and the other end is grounded. The dielectric 12 is made of FR-4; the silicone rubber 13 is used to seal the electrode 11 so that the discharge occurs on the other side of the dielectric 12.

[0019] In a possible implementation, first, the insulating material 10 to be treated is cleaned with anhydrous ethanol and deionized water, and then the insulating material 10 is dried for one hour, and the temperature is set to 60°C. Subsequently, the mechanical support structure 4 is adjusted so that the coplanar dielectric barrier discharge load 3 is directly opposite to the area to be modified of the insulating material 10, and the distance between the two is 0.3mm. The voltage regulator 1 is adjusted so that the output voltage of the plasma power supply 2 is about 8.25kV, so that the coplanar dielectric barrier discharge load 3 generates a macroscopically uniform low-temperature plasma, and the insulating material 10 is subjected to the modification mode of: power-on treatment for 90s, shutdown and heat dissipation for 180s, and the modification is repeated three times to complete the surface modification of the area to be modified of the insulating material 10.

[0020] The above specific implementation methods and examples are specific supports for the technical ideas proposed in the present invention, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or equivalent modifications made on the basis of the technical solution of the present invention in accordance with the technical ideas proposed in the present invention still fall within the scope of protection of the technical solution of the present invention.

[0021] The principle of generating low-temperature plasma by the coplanar dielectric barrier discharge device is as follows: when the applied voltage reaches a certain threshold, the gas in the coplanar dielectric barrier discharge device breaks down, generating discharge, the electrons are ionized and accelerated, the electrons and ions move in a directed manner in the electric field, collide with neutral particles, transfer momentum and energy to the surrounding air molecules, thereby generating an electron avalanche effect and finally forming a low-temperature plasma.

[0022] The mechanism of low-temperature plasma modification on the surface of insulating materials is as follows: Low-temperature plasma contains a large number of active particles with high energy, and the energy of these high-energy particles is generally in the range of several to dozens of electron volts. For most organic polymers, their binding energy is usually between 1 and 10 eV, so the particles in the plasma can break up the chemical bonds of organic macromolecules to reconstruct them. Since the energy of high-energy particles in low-temperature plasma is much lower than that of high-energy radioactive rays, it can optimize the surface performance of insulating materials without destroying the properties of the insulating materials themselves.

Claims

1. A coplanar dielectric barrier discharge device for surface modification of insulating materials, characterized in that: include: A voltage regulator is used to convert AC mains electricity into an AC voltage with adjustable voltage amplitude; A plasma power supply, used for converting the AC voltage output by the voltage regulator into an AC voltage with adjustable amplitude and fixed center frequency; A coplanar dielectric barrier discharge load is used to generate atmospheric pressure air low temperature plasma under the action of a plasma power supply; a mechanical support structure for supporting and moving a coplanar dielectric barrier discharge load; Data acquisition and analysis system, used to measure and record the actual working conditions of the coplanar dielectric barrier discharge load, and to perform protection actions and cut off the AC mains when abnormal working conditions are found; The data acquisition and analysis system includes: a current transformer, an oscilloscope, an infrared thermal imager and a computer; wherein the current transformer collects the output current of the plasma power supply and returns the data to the oscilloscope; the infrared thermal imager is used to measure the surface temperature of the insulating material when the device is working; the computer is used to analyze the output current and temperature, and issue a protection instruction in case of overcurrent or overtemperature to cut off the 220V AC mains power.

2. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 1, characterized in that: The plasma power supply model is Suman CTP-2000K, which can apply an AC high voltage with a fixed center frequency of 10kHz and an output voltage range of 0-30kV to the coplanar dielectric barrier discharge load.

3. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 1, characterized in that: The coplanar dielectric barrier discharge device comprises: electrodes, dielectrics and silicone rubber; wherein the electrodes are of a comb structure and made of copper foil, the electrodes are cross-arranged to form a discharge electrode pair, one end of which is connected to the output side of a plasma power supply and the other end is grounded; the dielectric is a solid dielectric; the silicone rubber is used to seal the electrodes so that discharge occurs on the other side of the dielectric.

4. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 1, characterized in that: The mechanical support structure includes: a height-adjustable lifting platform and a movable support track thereof; wherein the lifting platform can adjust the distance between the coplanar dielectric barrier load attached thereto and the surface of the insulating material to be processed; the movable support track is used to move the position of the lifting platform, thereby adjusting the processing area of ​​the coplanar dielectric barrier discharge load on the insulating material.

5. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 1, characterized in that: The electrode is a comb-shaped electrode structure, made of 35 μm thick copper foil, with an electrode width of 2 mm. High and low voltage electrodes are cross-arranged to form eight pairs of discharge electrodes.

6. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 3, characterized in that: The dielectric material is FR-4, and the thickness is 0.4 mm.

7. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 3, characterized in that: The silicone rubber model is K704-L, and the thickness is 2 mm.

8. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 1, characterized in that: The current transformer model is Pearson 6585, with an output sensitivity of 1V / A±1% and a rise time of 1.5ns.

9. A coplanar dielectric barrier discharge device for surface modification of insulating materials according to claim 1, characterized in that: The infrared thermal imager is Hikvision K20, with a resolution of 256×192 and a distance of 20 cm from the surface of the insulating material to be observed.

Images