An atmospheric pressure plasma device for online processing of large-diameter tubular braids

Abstract

The present invention discloses an atmospheric-pressure plasma device for online treatment of large-diameter tubular braids, belonging to the field of plasma application technology. Conventional plasma devices used for plasma treatment of large-diameter tubular braids suffer from technical deficiencies such as uneven discharge and easy burns. The device of the present invention comprises a coaxially arranged outer insulating tube and inner insulating tube, with the outer insulating tube sheathed over the inner insulating tube; a grounding electrode is provided on the inner wall of the inner insulating tube, and a high-voltage electrode is provided on the outer wall of the outer insulating tube. The large-diameter tubular braid is positioned within the discharge gap between the outer and inner insulating tubes, enabling low-energy, low-cost, uniform, and stable plasma treatment of the large-diameter tubular braid.

Description

Technical Field

[0001] The invention belongs to the technical field of plasma application, and in particular relates to a normal-pressure plasma device for online processing of large-caliber tubular braids. Background Art

[0002] Pipes used for firefighting or sewerage are mainly made of large-diameter tubular braids reinforced with polymer-based composite materials such as nitrile rubber, polyurethane, and EPDM rubber. However, due to the high surface crystallinity and strong inertness of high-performance fibers, the interfacial bonding strength between the reinforcement fiber fabric and the polymer resin matrix is ​​low, which is prone to peeling during use, seriously affecting the service life of the composite material.

[0003] To address these issues, high-performance fiber fabrics require physical or chemical surface treatment to increase surface roughness and surface activity, thereby enhancing the interfacial strength between the fiber and the polymer matrix. Key modification methods include chemical acid treatment, gamma-ray irradiation, chemical grafting, and plasma treatment. Conventional chemical treatments require a large amount of chemical reagents, resulting in significant environmental pollution and high costs. Gamma-ray irradiation requires large equipment and requires significant investment. Plasma treatment, however, is a fully dry, environmentally friendly process and is attracting increasing attention.

[0004] Atmospheric-pressure plasma is a key form of gas discharge. Due to its non-vacuum system, high energy density, and ease of formation, it has broad applications in a wide range of fields, including thin film deposition, plasma etching, and material surface treatment. Plasma treatment can introduce hydroxyl functional groups onto the microscopic surface of woven fabrics, improving their hydrophilicity. Currently, most commercial plasma treatment equipment on the market is vacuum-based and is often incapable of performing online fabric modification.

[0005] Due to its tubular structure and large thickness, generally 1mm to 3mm, large-diameter tubular braids need to be flattened and placed in the discharge gap when using conventional plasma devices. The thickness of the flattened sample is at least twice that of the single-sided fabric. In other words, the discharge gap is large, which easily leads to uneven discharge and causes sample burns. Summary of the Invention

[0006] In view of the technical deficiencies of existing conventional plasma devices in the plasma treatment of large-diameter tubular braids, such as uneven discharge and easy burns, the present invention provides an online atmospheric pressure plasma device for treating large-diameter tubular braids, which can achieve low-energy consumption, low-cost, uniform and stable plasma treatment of large-diameter tubular braids.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an online atmospheric pressure plasma device for processing large-diameter tubular braids, comprising an atmospheric pressure plasma excitation power supply, a high-voltage electrode, a grounding electrode, and an insulating assembly, wherein the insulating assembly comprises a coaxially arranged outer insulating tube and an inner insulating tube, and the outer insulating tube is sleeved on the outside of the inner insulating tube; the grounding electrode is arranged on the inner wall of the inner insulating tube, and the high-voltage electrode is arranged on the outer wall of the outer insulating tube; the large-diameter tubular braid is located in the discharge gap between the outer insulating tube and the inner insulating tube.

[0008] Furthermore, the outer insulating tube is detachably surrounded by a plurality of outer arc insulating sheets, the high-voltage electrode is connected by a plurality of high-voltage electrode sheets that are in contact with the outer wall of each of the outer arc insulating sheets, the inner insulating tube is detachably surrounded by a plurality of inner arc insulating sheets, and the grounding electrode is connected by a plurality of grounding electrode sheets that are in contact with the inner wall of each of the inner arc insulating sheets; the number of the outer arc insulating sheets and the number of the inner arc insulating sheets are at least 6 respectively.

[0009] Furthermore, the plurality of outer arc insulation sheets are evenly distributed around the outside of the plurality of inner arc insulation sheets, and each of the outer arc insulation sheets is concentric and parallel to the corresponding inner arc insulation sheet.

[0010] Furthermore, the high-voltage electrode sheet and the grounding electrode sheet are hollow structures, and the hollow structures of each two adjacent high-voltage electrode sheets are connected through the hollow structure of the high-voltage hollow connecting line to form an external air cooling passage, and the hollow structures of each two adjacent grounding electrode sheets are connected through the hollow structure of the grounding hollow connecting line to form an internal air cooling passage.

[0011] Furthermore, the discharge gap between the outer insulating tube and the inner insulating tube is 1 to 4 mm, and the thickness of the large-diameter tubular braid is 0.5 to 3.5 mm.

[0012] Furthermore, the high-voltage electrode is connected to the high-voltage output terminal of the atmospheric-pressure plasma excitation power supply through a high-voltage wire; and the ground electrode is connected to the ground terminal of the atmospheric-pressure plasma excitation power supply through a high-voltage wire.

[0013] Furthermore, the high-voltage wire is a high-temperature resistant DC silicone rubber high-voltage wire.

[0014] Furthermore, the atmospheric pressure plasma excitation power supply is an AC power supply with an output voltage of 0-30 kV, an operating frequency of 1-100 kHz, and a pulse modulation range of 25% to 100%.

[0015] Furthermore, the outer insulating tube and the inner insulating tube are made of quartz or ceramic.

[0016] Furthermore, the high voltage electrode and the ground electrode are made of thin copper sheets with a thickness of 0.02 to 1 mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention solves the technical problem that large-diameter tubular braids are difficult to process using a flat-plate device. By sleeveing ​​the outer insulating tube on the outside of the inner insulating tube and the discharge gap between the outer insulating tube and the inner insulating tube being tubular, the tubular braid is sleeved into the tubular discharge gap in a tubular shape, thereby achieving simultaneous treatment of the outer and inner surfaces of the tubular braid, resulting in better and more uniform surface modification effects. This results in better interface bonding performance during subsequent composite processing, avoids the need to flatten the tubular braid using a flat-plate device, and for braids with a relatively high weaving tightness, only one side of the two outer surfaces of the braid is processed, and the other side of the two outer surfaces and the two inner surfaces are difficult to process.

[0019] (2) The outer insulating tube is formed by a plurality of outer arc insulating sheets, and the inner insulating tube is formed by a plurality of inner arc insulating sheets. Due to the different diameters of the large-diameter pipe braids, the inner diameters of the outer insulating tube and the inner insulating tube can be changed by the detachable structure of the outer arc insulating sheets and the inner arc insulating sheets, so as to adapt to the diameters of the different large-diameter tubular braids; the present invention forms an external air cooling passage by connecting the hollow structure of the high-voltage electrode sheet with the hollow structure of the high-voltage hollow connecting line, and forms an external air cooling passage by connecting the hollow structure of the grounding electrode sheet with the hollow structure of the grounding hollow connecting line. The hollow structure is connected to form an inner air cooling passage, and the outer air cooling passage and the inner air cooling passage are ventilated respectively to achieve a cooling effect, so that the high-voltage electrode sheet and the ground electrode sheet are cooled more evenly, ensuring that the temperature of the high-voltage electrode sheet and the ground electrode sheet is not higher than 50°C; in addition, an outer arc insulation sheet gap is formed between each two adjacent outer arc insulation sheets, and an inner arc insulation sheet gap is formed between each two adjacent inner arc insulation sheets. The outer arc insulation sheet gaps are connected with the inner arc insulation sheet gaps to form a ventilation channel for connecting the internal airflow of the inner insulation tube with the outside to further dissipate heat;

[0020] (3) The plasma is generated by using a normal pressure dielectric barrier discharge, which has a high power density, is easy to start the discharge, and the discharge gas temperature is low and close to room temperature. It can produce a large number of active species when treating large-diameter tubular braids, and the discharge is uniform and stable, which is suitable for modifying the surface of the braid;

[0021] (4) The device of the present invention has a simple structure and is easy to operate. Since the present invention operates in an open atmospheric environment, it eliminates the need for expensive vacuum equipment, reduces production costs, and can provide a large number of reactive species. The treatment of woven fabrics can effectively improve their hydrophilic properties, enhance their adhesion in subsequent processes, and increase their wide application in industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 1 is a schematic cross-sectional view of the structure of the plasma device of Example 1;

[0023] Figure 2 This is a schematic top view of the structure of the plasma device of Example 1;

[0024] Figure 3 2 is a schematic cross-sectional view of the structure of the plasma device of Example 2;

[0025] Figure 4 This is a schematic cross-sectional view of the structure of the high-voltage electrode sheet and the high-voltage hollow connecting wire in Example 2;

[0026] Figure 5 This is a schematic top view of the structure of the plasma device of Example 2;

[0027] Among them, 1 is the normal pressure plasma excitation power supply, 2 is the high voltage electrode, 3 is the grounding electrode, 4 is the outer insulating tube, 5 is the inner insulating tube, 6 is the large-diameter tubular braid, 2-1 is the high voltage electrode sheet, 3-1 is the grounding electrode sheet, 4-1 is the outer arc insulating sheet, 5-1 is the inner arc insulating sheet, 7-1 is the high voltage hollow connecting wire, 7-2 is the grounding hollow connecting wire, 8-1 is the external air cooling inlet, 8-2 is the external air cooling outlet, 8-3 is the internal air cooling inlet, and 8-4 is the internal air cooling outlet. DETAILED DESCRIPTION

[0028] To make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings. The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0029] Example 1

[0030] This embodiment provides an atmospheric pressure plasma device for online processing of large-caliber tubular braids, such as Figure 1 and Figure 2As shown, it includes a normal pressure plasma excitation power supply 1, a high voltage electrode 2, a ground electrode 3, and an insulating assembly. The insulating assembly includes a coaxially arranged outer insulating tube 4 and an inner insulating tube 5, and the outer insulating tube 4 is sleeved on the outside of the inner insulating tube 5; the inner wall of the inner insulating tube 5 is provided with a ground electrode 3, and the outer wall of the outer insulating tube 4 is provided with a high voltage electrode 2; a large-diameter tubular braid 6 is located in the discharge gap between the outer insulating tube 4 and the inner insulating tube 5, and the large-diameter tubular braid 6 is inserted into the discharge gap in a tubular shape; the discharge gap between the outer insulating tube 4 and the inner insulating tube 5 is The diameter of the large-diameter tubular braid is 4mm, and the thickness of the large-diameter tubular braid is 3mm. The high-voltage electrode 2 is connected to the high-voltage output terminal of the atmospheric-pressure plasma excitation power supply 1 via a high-voltage conductor. The ground electrode 3 is connected to the ground terminal of the atmospheric-pressure plasma excitation power supply 1 via a high-voltage conductor. The high-voltage conductor is a high-temperature resistant DC silicone rubber high-voltage wire with a temperature resistance of 200°C and a withstand voltage of 5-100kV. The atmospheric-pressure plasma excitation power supply 1 is an AC power supply with an output voltage of 10kV, an operating frequency of 50kHz, and a pulse modulation range of 25%. The outer insulating tube 4 and the inner insulating tube 5 are made of quartz, with a wall thickness of 1mm and a dielectric constant of 9.0. The high-voltage electrode 2 and the ground electrode 3 are made of thin copper sheet with a thickness of 0.5mm.

[0031] The present invention also provides a plasma treatment method for a large-diameter tubular braid using the device of this embodiment, comprising the following steps:

[0032] (1) Under normal temperature and pressure, pass the large-diameter tubular braid 6 from top to bottom through the discharge gap between the outer insulating tube 4 and the inner insulating tube 5, and wind the bottom end of the large-diameter tubular braid 6 onto the roller and fix it;

[0033] (2) Connect the circuit, set the discharge parameters of the atmospheric pressure plasma excitation power supply 1 and the winding speed of the roller, mark the starting position of the treatment, turn on the atmospheric pressure plasma excitation power supply 1 to start the discharge, and the processed large-diameter tubular braid 6 will be wound onto the roller;

[0034] (3) After the treatment is completed, the atmospheric pressure plasma excitation power supply 1 is turned off to end the discharge.

[0035] The present embodiment provides a normal-pressure plasma device for online processing of large-diameter tubular braids, which can provide a higher density of reactive species and significantly improve the hydrophilicity of the braids. In particular, it can realize normal-pressure online real-time processing of large-diameter tubular braids, and has certain practical application prospects.

[0036] Example 2

[0037] This embodiment provides an atmospheric pressure plasma device for online processing of large-caliber tubular braids, such as Figures 3 to 5As shown, it includes a normal-pressure plasma excitation power supply 1, a high-voltage electrode 2, a ground electrode 3, and an insulating component. The insulating component includes a coaxially arranged outer insulating tube 4 and an inner insulating tube 5, and the outer insulating tube 4 is sleeved on the outside of the inner insulating tube 5. A tubular discharge gap is formed between the outer insulating tube and the inner insulating tube, and the discharge gap is used to place a large-diameter tubular braid 6.

[0038] like Figures 3 to 5 As shown, the outer insulating tube 4 is formed by 48 removably enclosing outer arc insulating sheets 4-1, the high-voltage electrode 2 is formed by connecting 48 high-voltage electrode sheets 2-1 that adhere to the outer wall of each outer arc insulating sheet 4-1, the inner insulating tube 5 is formed by 48 removably enclosing inner arc insulating sheets 5-1, and the grounding electrode 3 is formed by connecting 48 grounding electrode sheets 3-1 that adhere to the inner wall of each inner arc insulating sheet 5-1. The 48 outer arc insulating sheets are evenly distributed around the outside of the 48 inner arc insulating sheets, with each outer arc insulating sheet being concentric and parallel to each inner arc insulating sheet. The high-voltage and grounding electrode sheets are hollow structures. The hollow structures of each adjacent high-voltage electrode sheet are connected by the hollow structure of the high-voltage hollow connecting line 7-1, forming an external air cooling path for cooling each high-voltage electrode sheet. The hollow structures of each adjacent grounding electrode sheet are connected by the hollow structure of the grounding hollow connecting line 7-2, forming an internal air cooling path for cooling each grounding electrode sheet. An external air cooling inlet 8-1 and an external air cooling outlet 8-2 of an external air cooling passage are respectively provided on a high-voltage electrode sheet, and cold air passes through the external air cooling passage from the external air cooling inlet to the external air cooling outlet. An internal air cooling inlet 8-3 and an internal air cooling outlet 8-4 of an internal air cooling passage are respectively provided on a grounding electrode sheet, and cold air passes through the internal air cooling passage from the internal air cooling inlet to the internal air cooling outlet.

[0039] The discharge gap between the outer and inner insulating tubes is 1 mm, and the thickness of the large-diameter tubular braid is 0.5 mm. The high-voltage electrode 2 is connected to the high-voltage output terminal of the atmospheric-pressure plasma excitation power supply 1 via a high-voltage conductor; the ground electrode 3 is connected to the ground terminal of the atmospheric-pressure plasma excitation power supply 1 via a high-voltage conductor. The high-voltage conductor is a high-temperature-resistant DC silicone rubber high-voltage wire with a temperature resistance of 200°C and a withstand voltage of 5-100 kV. The atmospheric-pressure plasma excitation power supply 1 is an AC power supply with an output voltage of 10 kV, an operating frequency of 50 kHz, and a pulse modulation range of 100%. The outer and inner insulating tubes are made of ceramic, and the outer and inner arc insulating sheets 4-1 and 5-1 have a wall thickness of 1 mm. The high-voltage electrode sheet 2-1 and the ground electrode sheet 3-1 are made of thin copper sheet with a thickness of 1 mm. The high-voltage hollow connecting wire and the grounding hollow connecting wire are made of copper wire, which has good electrical conductivity.

[0040] In addition to providing a higher reactive species density and significantly improving the hydrophilicity of the braid, this embodiment can also be formed by the outer insulating tube being surrounded by multiple outer arc insulating sheets, and the inner insulating tube being surrounded by multiple inner arc insulating sheets. Since the diameters of different large-diameter pipe braids are different, the inner diameters of the outer and inner insulating tubes can be changed by the detachable structure of the outer and inner arc insulating sheets, thereby adapting to the diameters of different large-diameter pipe braids.

[0041] The hardness of the copper wire is used to give the high-voltage hollow connecting wire and the grounding hollow connecting wire a certain supporting function. Only one outer arc insulating sheet and one inner arc insulating sheet need to be externally fixed. In addition, if the inner diameter of the outer insulating tube and the inner insulating tube needs to be increased or decreased, the number of the outer arc insulating sheet and the inner arc insulating sheet only needs to be increased or decreased at one end. There is no need to dismantle the entire structure, and it is easy to use.

[0042] The present invention forms an external air cooling passage by connecting the hollow structure of the high-voltage electrode sheet with the hollow structure of the high-voltage hollow connecting line, and forms an internal air cooling passage by connecting the hollow structure of the grounding electrode sheet with the hollow structure of the grounding hollow connecting line. The external air cooling passage and the internal air cooling passage are ventilated separately to achieve a cooling effect, so that the high-voltage electrode sheet and the grounding electrode sheet are cooled more evenly, ensuring that the temperature of the high-voltage electrode sheet and the grounding electrode sheet is not higher than 50°C; in addition, an outer arc insulating sheet gap is formed between each two adjacent outer arc insulating sheets, and an inner arc insulating sheet gap is formed between each two adjacent inner arc insulating sheets. The outer arc insulating sheet gaps are connected with the inner arc insulating sheet gaps to form a through channel, which is used to connect the internal airflow of the inner insulating tube with the outside for further heat dissipation.

[0043] In addition, it should be understood that although this specification is described in terms of implementation methods, the implementation methods do not only include an independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An atmospheric pressure plasma device for online processing of large-caliber tubular braids, comprising an atmospheric pressure plasma excitation power supply (1), a high-voltage electrode (2), a ground electrode (3), and an insulating component, characterized in that: The insulating assembly comprises an outer insulating tube (4) and an inner insulating tube (5) which are coaxially arranged, and the outer insulating tube (4) is sleeved on the outside of the inner insulating tube (5); the grounding electrode (3) is arranged on the inner wall of the inner insulating tube (5), and the high-voltage electrode (2) is arranged on the outer wall of the outer insulating tube (4); a large-diameter tubular braid (6) is located in the discharge gap between the outer insulating tube (4) and the inner insulating tube (5); The outer insulating tube (4) is formed by a plurality of outer arc insulating sheets (4-1) detachably enclosed, the high-voltage electrode (2) is formed by connecting a plurality of high-voltage electrode sheets (2-1) that are in contact with the outer wall of each outer arc insulating sheet (4-1), the inner insulating tube (5) is formed by a plurality of inner arc insulating sheets (5-1) detachably enclosed, and the grounding electrode (3) is formed by connecting a plurality of grounding electrode sheets (3-1) that are in contact with the inner wall of each inner arc insulating sheet (5-1); The high-voltage electrode sheet and the grounding electrode sheet are hollow structures. The hollow structures of each two adjacent high-voltage electrode sheets are connected through the hollow structure of a high-voltage hollow connecting line (7-1) to form an external air cooling passage. The hollow structures of each two adjacent grounding electrode sheets are connected through the hollow structure of a grounding hollow connecting line (7-2) to form an internal air cooling passage.

2. The atmospheric pressure plasma device for online processing of large-diameter tubular braids according to claim 1 is characterized in that: The plurality of outer arc insulation sheets are evenly distributed around the outside of the plurality of inner arc insulation sheets, and each outer arc insulation sheet is concentric and parallel to the corresponding inner arc insulation sheet.

3. The atmospheric pressure plasma device for online processing of large-diameter tubular braids according to claim 1 is characterized in that: The discharge gap between the outer insulating tube (4) and the inner insulating tube (5) is 1 to 4 mm.

4. The atmospheric pressure plasma device for online processing of large-diameter tubular braids according to claim 1 is characterized in that: The high-voltage electrode (2) is connected to the high-voltage output end of the atmospheric-pressure plasma excitation power supply (1) via a high-voltage wire; and the grounding electrode (3) is connected to the grounding end of the atmospheric-pressure plasma excitation power supply (1) via a high-voltage wire.

5. The atmospheric pressure plasma device for online processing of large-diameter tubular braids according to claim 4, characterized in that: The high-voltage wire is a high-temperature resistant DC silicone rubber high-voltage wire.

6. The atmospheric pressure plasma device for online processing of large-diameter tubular braids according to claim 1, characterized in that: The atmospheric pressure plasma excitation power supply (1) is an AC power supply with an output voltage of 0-30 kV, an operating frequency of 1-100 kHz, and a pulse modulation range of 25% to 100%.

7. The atmospheric pressure plasma device for online processing of large-diameter tubular braids according to claim 1, characterized in that: The outer insulating tube and the inner insulating tube are made of quartz or ceramic.

8. The atmospheric pressure plasma device for online processing of large-diameter tubular braids according to claim 1, characterized in that: The high-voltage electrode (2) and the grounding electrode (3) are made of thin copper sheets with a thickness of 0.02 to 1 mm.

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