A non-breakdown corona mechanism

Abstract

The utility model discloses a kind of anti-penetration's corona mechanism, including corona roller, corona electrode, corona cover, air knife, corona press roller and idler roller;The corona roller is arranged below the corona cover;The corona electrode is arranged in the inner wall of the corona cover, and the air knife is arranged on the outer wall of the corona cover;The corona press roller is arranged on one side of the corona roller, and the idler roller is arranged on the other side;Film is sequentially bypassed the corona press roller, the corona roller and the idler roller.The first cavity is arranged in the corona roller, the second cavity of annular is arranged outside the first cavity, and the rubber layer is arranged outside the second cavity, and the utility model aims at overcoming the defects of the prior art and provides a kind of anti-penetration's corona mechanism, suitable for the surface corona modification treatment of various plastic films, metallized film materials, can effectively avoid the breakdown damage of film in the process of corona due to air layer, wrinkle problem, improve corona treatment quality and production stability.

Description

Technical Field

[0001] This utility model relates to a corona-resistant mechanism for preventing breakdown. Background Technology

[0002] In the thin film processing industry, corona treatment is a key process for improving the surface tension of thin films and enhancing the adhesion of subsequent printing, lamination, and other processes. Its principle is to create a high-voltage electric field between the electrode and the corona roller, causing air ionization and generating corona discharge, which etches and activates the film surface.

[0003] However, existing corona treatment mechanisms have the following technical defects in practical applications: air layers can lead to breakdown. When the film travels on the surface of the corona roller, air layers can easily form between the film and the roller surface due to insufficient film flatness and fluctuations in travel speed. Under a high-voltage electric field, the air layer is easily broken down and an electric arc is triggered, causing localized burning and damage to the film. This risk of breakdown is significantly increased, especially for thinner films (such as those below 20 μm).

[0004] Film wrinkles cause malfunctions: In traditional corona treatment mechanisms, the wrap angle control precision of the film on the corona roller is low, making the film prone to local wrinkles. The electric field intensity at the wrinkle will be abnormally concentrated, which can lead to corona breakdown and seriously affect the product qualification rate. To address the aforementioned issues, there is an urgent need to design an anti-corona discharge mechanism that can effectively eliminate air layers, flatten the film, and stably compress it, in order to solve the problems of high film corona discharge rate and poor processing quality in existing technologies.

[0005] CN112046038A discloses a plastic film production equipment, the structure of which includes a machine body, a control panel, a pressure roller, and a pressure block. The control panel is installed on the top front of the machine body, and the pressure roller and pressure block are fixed inside the front of the machine body and cooperate with each other. When using a corona treatment machine to corona treat the plastic film, a smoothing device smooths the plastic film before corona treatment to reduce unevenness between film surfaces. Air can enter the corona treatment machine with the film, easily causing the reverse side of the film to be corona treated as well, resulting in ink staining on the reverse side of the film during use, affecting the normal use of the film. Because the contact area between the film and the corona roller is large during corona treatment, the smoothing mechanism cannot guarantee the amount of air entering over the entire contact area between the film and the corona roller, so this equipment still has a certain risk of corona breakdown.

[0006] CN222645405U discloses an anti-reverse corona structure for plasma plating processes in aluminum plating machines, relating to the field of aluminum plating film technology. It includes a baffle and an insulating base. The insulating base is installed in the vacuum chamber of the aluminum plating machine and supports the baffle. The end of the baffle extends between the edge of the film and the electrode. The position of the baffle is adjustable along the insulating base, changing the width of the baffle blocking the edge of the film. This invention utilizes the baffle to block the film edge between the electrode and the electrode, preventing reverse corona at the film edge, avoiding excessive corona treatment of the film edge, and ensuring the heat-sealing performance of the aluminum-plated film edge. The width of the baffle blocking the film edge is adjustable to ensure the anti-reverse corona effect. This structure only considers preventing corona breakdown at the film edge and cannot guarantee the reverse corona situation across the entire width of the film.

[0007] Therefore, a corona-proof mechanism to prevent breakdown is proposed to address the above problems. Utility Model Content

[0008] The purpose of this invention is to overcome the existing defects and provide a corona-proof mechanism that is suitable for surface corona modification treatment of various plastic films and metallized film materials. It can effectively prevent the film from being damaged by breakdown due to air layer and wrinkle problems during the corona treatment process, thereby improving the quality of corona treatment and production stability.

[0009] To achieve the above objectives, this utility model provides the following technical solution: a corona mechanism for preventing breakdown, comprising a corona roller, a corona electrode, a corona cover, an air knife, a corona pressure roller, and an idler roller; The corona roller is positioned below the corona hood; the corona electrode is positioned on the inner wall of the corona hood, and the air knife is positioned on the outer wall of the corona hood; the corona pressure roller is positioned on one side of the corona roller, and the idler roller is positioned on the other side. The film passes sequentially around the corona roller, the corona roller, and the idler roller.

[0010] Preferably, the corona roller has a first cavity inside, an annular second cavity outside the first cavity, a rubber layer outside the second cavity, a mandrel passing through the middle of the first cavity, a vacuum channel in the middle of the mandrel, an air pipe connected to the vacuum channel, and one end of the air pipe extending into the second cavity.

[0011] Preferably, a plurality of first vent holes are formed on the rubber layer, and the vent holes are connected to a plurality of second vent holes formed on the surface of the second cavity.

[0012] Preferably, there are two air knives, located on both sides of the corona shield.

[0013] Preferably, the air inlet of the air knife is connected to a high-pressure blower.

[0014] Preferably, the rubber layer is made of nitrile rubber.

[0015] Preferably, the vacuum channel is connected to a rotary vane vacuum pump.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: The anti-breakdown corona mechanism has a significant anti-breakdown effect: Through the dual clamping structure of "vacuum adsorption + air knife assistance", the air layer between the film and the corona roller is completely eliminated. At the same time, the 180° maximum wrap angle design avoids film wrinkles, fundamentally solving the corona breakdown problem caused by air layer and wrinkles. The film breakdown rate can be reduced from more than 5% in the prior art to less than 0.1%. High uniformity of corona treatment: Vacuum holes (1~2mm in diameter) are evenly distributed to ensure uniform film adsorption force; the air knife blowing direction is consistent with the film's travel direction, avoiding interference of airflow on film tension, and removing corona impurities, thereby increasing the uniformity of corona activation on the film surface by more than 20%. High adaptability: The clamping force of the rubber corona roller can be flexibly adjusted according to the film thickness (e.g., 10~100μm) and material. The vacuum hole diameter (1~2mm) design takes into account both adsorption force and air permeability, making it suitable for the corona treatment needs of various films and highly versatile. Stable and reliable structure: The corona roller adopts a multi-layer sealing structure of "mandrel - first cavity - second cavity - rubber layer", with a low vacuum leakage rate (≤0.1Pa・m). 3 / s); The air knife is built into the corona hood, which avoids external dust from clogging the air knife outlet, extends the service life of the equipment, and reduces maintenance costs. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a plan view of the anti-breakdown corona mechanism of this utility model; Figure 2 This is a cross-sectional view of the corona roller of this utility model.

[0018] In the figure: 1. Corona electrode; 2. Corona cover; 3. Air knife; 4. Corona pressure roller; 5. Inert roller; 6. Film; 21. Mandrel; 22. First cavity; 23. Second cavity; 24. Rubber layer; 211. Vacuum channel. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] like Figure 1-2 As shown, a corona discharge protection mechanism includes a corona roller, a corona electrode 1, a corona cover 2, an air knife 3, a corona pressure roller 4, and an idler roller 5. The corona roller is positioned below the corona cover 2. The corona electrode 1 is disposed on the inner wall of the corona cover 2, and the air knife 3 is disposed on the outer wall of the corona cover 2. The corona pressure roller 4 is disposed on one side of the corona roller, and the idler roller 5 is disposed on the other side. A film 6 passes sequentially around the corona pressure roller 4, the corona roller, and the idler roller 5. There are two air knives 3, located on both sides of the corona cover 2. The air inlets of the air knives 3 are connected to a high-pressure blower.

[0021] Specifically, the corona roller has a first cavity 22 inside, an annular second cavity 23 outside the first cavity 22, and a rubber layer 24 outside the second cavity 23. A mandrel 21 runs through the middle of the first cavity 22, and a vacuum channel 211 is formed in the middle of the mandrel 21. An air pipe is connected inside the vacuum channel 211, and one end of the air pipe extends into the second cavity 23. Multiple first vent holes are formed on the rubber layer 24, and these vent holes communicate with multiple second vent holes formed on the surface of the second cavity 23. The rubber layer 24 is made of nitrile rubber. The vacuum channel 211 is connected to a rotary vane vacuum pump.

[0022] Specifically, the corona roller's spindle 21 is made of 304 stainless steel, with a length of 1500mm and a diameter of 80mm, and the internal vacuum channel 211 has a diameter of 30mm; the first cavity 22 is 10mm thick and is welded from a 2mm thick 304 stainless steel plate; the second cavity 23 is 8mm thick and is also welded from a 2mm thick 304 stainless steel plate; the rubber layer 24 is made of nitrile rubber, with a thickness of 4mm and a hardness of 70 Shore A, and has a first vent hole with a diameter of 1.5mm, a vent spacing of 20mm, and is connected to the second cavity 23.

[0023] Specifically, the corona cover 2 is made of cold-rolled steel plate with powder coating, with a length of 1600mm, a width of 200mm, and a height of 150mm; the corona electrode 1 is made of tungsten copper alloy, with a diameter of 8mm and a length of 1450mm, and the distance between it and the corona roller is adjustable to 2mm; the air knife 3 is made of aluminum alloy, with a length of 1450mm and an outlet width of 4mm. The two air knives 3 are installed on the front and rear sides of the corona electrode 3, respectively. The distance between the outlet 31 and the surface of the corona roller is 2.5mm. The air inlet of the air knife 3 is connected to a high-pressure fan with a pressure of 0.3MPa and an air volume of 120m³. 3 / h; Specifically, the rubber corona roller 4 has a diameter of 60mm, a length of 1500mm, a rubber layer thickness of 10mm, is made of silicone rubber, has a hardness of 65 Shore A, and is driven by a cylinder of model SC63×50, with a pressing force adjustable to 120N; the idler roller 5 is made of 45# steel, has a diameter of 50mm, a length of 1500mm, a chrome-plated surface, and a roughness of Ra0.8μm. Specifically, the vacuum roller mandrel 21 is connected to an external vacuum equipment rotary vane vacuum pump with a pumping capacity of 200L / min and an ultimate vacuum of 0.098MPa. It is sealed to the vacuum channel 211 of the mandrel 21 through a vacuum hose.

[0024] Specifically, in this embodiment, when processing PET films with a thickness of 30μm, the anti-breakdown corona mechanism achieves a wrap angle of 180° on the corona roller, uniform vacuum adsorption force, stable air blowing by the air knife 3, no film breakdown during corona treatment, and increases the film surface tension from 32dyn / cm to 48dyn / cm with a surface tension uniformity error ≤2dyn / cm, resulting in a product qualification rate of over 99.9%.

[0025] Specifically, the mandrel 21 has a hollow structure and a vacuum channel 211 inside. One end of the vacuum channel 211 is sealed to an external vacuum device, and the other end is connected to the first cavity 22. Specifically, the first cavity 22 is an annular cavity, coaxially sleeved on the outside of the mandrel 21, with its inner wall sealed and fixed to the outer wall of the mandrel 21, and its outer wall sealed and fixed to the inner wall of the second cavity 23, for uniformly transmitting the negative pressure generated by the vacuum equipment to the second cavity 23; Specifically, the second cavity 23 is an annular cavity, coaxially sleeved on the outside of the first cavity 22, and its sidewalls are evenly provided with second vent holes with a diameter of 1~2mm; Specifically, the rubber layer 24 is an elastic wear-resistant layer that wraps around the outside of the second cavity 23. Its thickness is 3~5mm. The rubber layer 24 has a first vent hole of the same diameter at the position corresponding to the second vent hole of the second cavity. The second vent hole and the first vent hole are connected to each other to form a vacuum hole that penetrates the second cavity 22 and the rubber layer 24. By evacuating the air with a vacuum device, the vacuum hole can generate negative pressure, which tightly adsorbs the film onto the surface of the rubber layer and avoids the formation of an air layer between the film and the corona roller. Specifically, the corona cover 2 is fixedly installed on the frame and is located above the corona roller. The corona electrode 1 is horizontally arranged inside the corona cover 2 and is parallel to the axis of the corona roller. The distance between the two can be adjusted according to the film thickness (adjustment range is 1.5~2mm). Specifically, there are two air knives 3, which are fixedly installed on the front and rear sides inside the corona cover 2 (along the film traveling direction). The air outlet of the air knife 3 faces the surface of the corona roller 2, and the distance between the air outlet and the surface of the corona roller is 2~3mm. Specifically, the air inlet of the air knife 3 is connected to an external high-pressure blower through an air duct. The compressed air generated by the high-pressure blower forms a uniform airflow through the air knife outlet, blowing air onto the film surface along the film's travel direction. On the one hand, this helps to press the film tightly onto the surface of the corona roller, and on the other hand, it can promptly blow away ozone and impurities generated during the corona treatment process, improving the cleanliness of the corona treatment environment. Specifically, along the traveling direction of the film 6, a rubber corona roller 4 is installed on one side (film entry side) of the corona roller, and an idler roller 5 is installed on the other side (film exit side). The rubber corona roller 4 is arranged parallel to the corona roller and is movable by a cylinder to adjust the clamping force on the film (the clamping force adjustment range is 50~200N). The idler roller 5 is a smooth metal roller and is arranged parallel to the corona roller. Through the cooperation of the rubber corona roller and the idler roller, the wrap angle of the film on the corona roller can reach up to 180°, ensuring that the film is completely flattened during the corona process and avoiding the problem of electric field concentration breakdown caused by wrinkles. The specific process of this anti-breakdown corona mechanism during operation is as follows: Film conveying and positioning: After the film is released from the unwinding mechanism, it is guided and pressed by the rubber corona pressure roller 4 and idler roller 5, and finally adheres to the surface of the rubber layer 24 of the corona roller; by adjusting the pressing force of the rubber corona pressure roller, in conjunction with the guiding action of the idler roller, the film forms a maximum wrap angle of 180° on the corona roller, so as to achieve full flattening of the film. Vacuum adsorption start-up: Start the external vacuum equipment. The vacuum equipment draws air into the first chamber 22 through the vacuum channel inside the mandrel 21. The first chamber 22 transmits the negative pressure evenly to the second chamber 23. Then, negative pressure is generated through the vacuum holes (1~2mm in diameter) on the rubber layer in the second chamber, which tightly adsorbs the film onto the surface of the rubber layer of the corona roller, completely eliminating the air between the film and the corona roller, and preventing the air layer from being broken down under the high voltage electric field. Corona treatment and air knife assistance: When the corona power supply is turned on, a high-voltage electric field is formed between the corona electrode and the corona roller to perform corona activation treatment on the film surface; at the same time, the high-pressure blower is turned on, and compressed air forms a uniform airflow through the air knives on the front and rear sides of the corona hood, blowing air along the film surface. On the one hand, this further presses the film onto the surface of the corona roller to enhance the adsorption effect, and on the other hand, it removes ozone and impurities generated during the corona treatment in a timely manner, ensuring the uniformity and stability of the corona treatment. Post-treatment conveying: After the corona treatment is completed, the film is detached from the film exit side of the corona roller and conveyed to the winding mechanism by the subsequent traction mechanism to complete the entire corona treatment process.

[0026] This anti-breakdown corona mechanism has a significant anti-breakdown effect: through the dual clamping structure of "vacuum adsorption + air knife assistance", the air layer between the film and the corona roller is completely eliminated. At the same time, the 180° maximum wrap angle design avoids film wrinkles, fundamentally solving the corona breakdown problem caused by air layer and wrinkles. The film breakdown rate can be reduced from more than 5% in the existing technology to less than 0.1%. High uniformity of corona treatment: Vacuum holes (1~2mm in diameter) are evenly distributed to ensure uniform film adsorption force; the air knife blowing direction is consistent with the film's travel direction, avoiding interference of airflow on film tension, and removing corona impurities, thereby increasing the uniformity of corona activation on the film surface by more than 20%. High adaptability: The clamping force of the rubber corona roller can be flexibly adjusted according to the film thickness (e.g., 10~100μm) and material. The vacuum hole diameter (1~2mm) design takes into account both adsorption force and air permeability, making it suitable for the corona treatment needs of various films and highly versatile. Stable and reliable structure: The corona roller adopts a multi-layer sealing structure of "mandrel - first cavity - second cavity - rubber layer", with a low vacuum leakage rate (≤0.1Pa・m). 3 / s); The air knife is built into the corona hood, which avoids external dust from clogging the air knife outlet, extends the service life of the equipment, and reduces maintenance costs.

[0027] Finally, it should be noted that the above are merely preferred embodiments of this utility model and are not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A corona-resistant mechanism for preventing breakdown, characterized in that, It includes a corona roller, a corona electrode (1), a corona cover (2), an air knife (3), a corona pressure roller (4), and an idler roller (5); The corona roller is positioned below the corona cover (2); the corona electrode (1) is positioned on the inner wall of the corona cover (2), and the air knife (3) is positioned on the outer wall of the corona cover (2); the corona pressure roller (4) is positioned on one side of the corona roller, and the idler roller (5) is positioned on the other side. The film (6) passes sequentially around the corona roller (4), the corona roller and the idler roller (5); The corona roller has a first cavity (22) inside, and a second annular cavity (23) outside the first cavity (22). A rubber layer (24) is provided outside the second cavity (23). A mandrel (21) runs through the middle of the first cavity (22). A vacuum channel (211) is opened in the middle of the mandrel (21). An air pipe is connected inside the vacuum channel (211), and one end of the air pipe extends into the second cavity (23).

2. The anti-breakdown corona mechanism according to claim 1, characterized in that, Multiple first vent holes are formed on the rubber layer (24), and the vent holes are connected to multiple second vent holes formed on the surface of the second cavity (23).

3. The anti-breakdown corona mechanism according to claim 1, characterized in that, There are two air blades (3), located on both sides of the corona shield (2).

4. The anti-breakdown corona mechanism according to claim 1, characterized in that, The air inlet of the air knife (3) is connected to a high-pressure blower.

5. The anti-breakdown corona mechanism according to claim 1, characterized in that, The rubber layer (24) is made of nitrile rubber.

6. The anti-breakdown corona mechanism according to claim 1, characterized in that, The vacuum channel (211) is connected to a rotary vane vacuum pump.

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