A high-speed hot air device for polyimide film

Abstract

This invention belongs to the field of thin film production technology, specifically relating to a high-speed hot air device for polyimide film. It includes a hot air box serving as the reaction site for the film. Hot air plates are installed on the left and right sides of the hot air box, each plate having a hollow structure. Each hot air plate has a blower nozzle facing the film, one blowing towards the upper surface of the film and another blowing towards the lower surface. Exhaust mechanisms are installed at the upper and lower ends of the hot air box, connected to a cooling mechanism via a connecting pipe. The cooling mechanism is located on one side of the hot air box. This invention allows hot air to be blown into the hot air box, through which the film passes, and the reaction takes place. The generated moisture is discharged with the hot air through the exhaust mechanism, ensuring timely removal of moisture from the film. This facilitates better imidization of the film and prevents moisture accumulation in the hot air box.

Description

Technical Field

[0001] This invention belongs to the field of thin film production technology, specifically relating to a high-speed hot air device for polyimide film. Background Technology

[0002] Polyester imide film is a high-performance engineering plastic film that combines the excellent mechanical properties of polyester film with the superior heat resistance of polyimide film. Therefore, it has wide applications in many demanding industrial and electronic fields, such as high-temperature motor insulation, flexible circuit board substrates, and high-temperature pressure-sensitive tapes. The imidization of polyester film mainly involves: polyamic acid → (dehydration) → polyimide + water. During the imidization production of polyester imide film, the moisture in the film needs to be evaporated by heating to obtain the polyester imide film.

[0003] For example, the hot air uniform flow drying device for polyimide film production disclosed in Chinese Patent Application Publication No. CN223354722U includes a processing box; support bars are symmetrically installed on the front and rear sides of the lower end of the processing box, and support seats are symmetrically installed on the lower ends of the support bars; a filter box is provided in the middle of the upper and lower ends of the processing box; a fan is installed inside the filter box; an inlet and an outlet are respectively opened at the front and rear ends of the processing box; a first air blowing box and a second air blowing box are symmetrically arranged inside the processing box; a high-temperature box is provided between the first air blowing box and the second air blowing box; an external controller starts the fan to deliver gas to the first air blowing box, and at the same time starts the heating rod to heat the gas discharged from the first air blowing box. This device achieves the purpose of heating the film by setting up multiple sets of air blowing boxes and installing heating rods in the air blowing boxes.

[0004] However, in the prior art described in the aforementioned patent, there is no ventilation mechanism, which makes it difficult for the moisture generated by the film to evaporate when heated, thus resulting in incomplete imidization of the film. Utility Model Content

[0005] The purpose of this invention is to provide a high-speed hot air device for polyimide films, which can blow hot air into the films and, most importantly, can promptly remove the moisture generated during the imidization process of the films.

[0006] The specific technical solution adopted in this utility model is as follows: A high-speed hot air device for polyimide film includes a hot air box serving as the film reaction site. Hot air plates are installed on the left and right sides of the hot air box, and the hot air plates have a cavity structure. Each hot air plate has a blower opening one blowing towards the upper surface of the film and a blower opening two blowing towards the lower surface of the film. Exhaust mechanisms are installed at the upper and lower ends of the hot air box, and the exhaust mechanisms are connected to a cooling mechanism via a connecting pipe two. The cooling mechanism is located on one side of the hot air box.

[0007] In a preferred embodiment, the two ends of the hot air box are respectively the feed port for entering the film and the discharge port for exiting the film, and guide rollers that guide the film are installed at both ends of the inner side of the hot air box.

[0008] In a preferred embodiment, each of the hot air plates has a connecting pipe installed on its outer end for connection to a hot air blower.

[0009] In a preferred embodiment, the exhaust mechanism includes an exhaust duct communicating with a hot air box, an exhaust fan rotatably disposed inside the exhaust duct, a drive motor connected to the shaft of the exhaust fan, a connecting cover installed at the outer end of the exhaust duct, and a connecting pipe connected to the connecting cover.

[0010] In a preferred embodiment, the cooling mechanism includes a cooling box, an air inlet pipe and an exhaust pipe are respectively installed on the upper end of the cooling box, two liquid level sensors of different heights, a liquid level sensor 1 and a liquid level sensor 2 are installed on the side wall of the cooling box, a cooling pipe is installed at the bottom of the interior of the cooling box, a drain pipe is installed at the lower end of the cooling box, a control valve is installed on the drain pipe, and heat dissipation fins are also provided on the outer wall of the cooling box.

[0011] In a preferred embodiment, the height of the first liquid level sensor is lower than the height of the second liquid level sensor, and the lowest end of the air inlet pipe is lower than the measuring position of the first liquid level sensor, while the lowest end of the exhaust pipe is higher than the measuring position of the second liquid level sensor, and the second connecting pipe is connected to the upper port of the air inlet pipe.

[0012] The technical effects achieved by this utility model are as follows: This invention involves blowing hot air into a hot air chamber, through which the thin film passes to react. The resulting moisture is then discharged with the hot air via an exhaust system, ensuring timely removal of moisture from the film. This facilitates better imidization of the film and prevents moisture accumulation within the hot air chamber. Furthermore, the hot air plate for blowing hot air onto the film has two outlets, one for blowing air onto the upper surface and the other for blowing air onto the lower surface of the film, resulting in more uniform and rapid heating of the film. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this practical tool; Figure 2 This is a half-section enlarged structural diagram of this practical hot air box; Figure 3 This is an enlarged cross-sectional structural diagram of this practical hot air box; Figure 4 This is a schematic diagram of the enlarged cross-section of the practical cooling mechanism.

[0014] The attached diagram lists the components represented by each number as follows: 1. Hot air box; 2. Hot air plate; 3. Exhaust mechanism; 4. Cooling mechanism; 11. Discharge port; 12. Inlet port; 13. Guide roller; 21. Air outlet one; 22. Air outlet two; 23. Connecting pipe one; 31. Exhaust duct; 32. Exhaust fan; 33. Drive motor; 34. Connecting cover; 35. Connecting pipe two; 41. Cooling box; 42. Air inlet pipe; 43. Exhaust pipe; 44. Liquid level sensor one; 45. Liquid level sensor two; 46. Heat sink fins; 47. Cooling pipe; 48. Drain pipe; 49. Control valve. Detailed Implementation

[0015] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0016] Many specific details are set forth in the following description in order to provide a full understanding of this utility model. However, this utility model may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0017] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this utility model. The phrase "in a preferred embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments.

[0018] Secondly, this utility model is described in detail with reference to the schematic diagrams. When detailing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.

[0019] Please see the appendix Figures 1 to 3 As shown, this utility model provides a high-speed hot air device for polyimide film, including a hot air box 1 as the film reaction site. Hot air plates 2 are installed on the left and right sides of the hot air box 1, and the hot air plates 2 have a cavity structure. Each hot air plate 2 is provided with an air outlet 21 blowing towards the upper end of the film and an air outlet 22 blowing towards the lower end of the film. Exhaust mechanisms 3 are installed at the upper and lower ends of the hot air box 1, and the exhaust mechanisms 3 are connected to the cooling mechanism 4 through connecting pipe 35. The cooling mechanism 4 is located on one side of the hot air box 1. The two ends of the hot air box 1 are the feed inlet 12 for entering the film and the discharge outlet 11 for exiting the film. Guide rollers 13 that guide the film are installed at both ends of the inner side of the hot air box 1. The entire imidization process of thin films can be divided into three stages, with the heat treatment process being the core. The first stage is the solvent evaporation and preliminary molding stage, and the temperature in this stage is usually controlled within the range of 80°C-150°C.

[0020] The second stage is thermal imidization (the main reaction stage), which is the most crucial stage. It occurs at a higher temperature and promotes the dehydration and cyclization of polyamic acid.

[0021] The temperature during this stage is typically controlled within the range of 150°C to 350°C. This stage is a heating process, which is further divided into a medium-temperature stage and a high-temperature stage. Intermediate temperature stage (150°C-250°C): The imidization reaction begins to accelerate, and a large amount of small water molecules are released. During this stage, it is necessary to control the heating rate and ventilation to allow water molecules to diffuse slowly and evenly out of the film, avoiding the formation of bubbles. High-temperature stage (250°C-350°C): Ensures the reaction is as complete as possible. At this temperature, the polymer chain segments are more mobile, which facilitates unreacted groups finding each other to complete cyclization, and also helps to completely remove residual solvent.

[0022] The third stage is the high-temperature heat treatment and structural improvement stage, where the temperature may reach 350°C-500°C (depending on the target product). After this stage, the performance of the film is further improved.

[0023] It is worth noting that this device is suitable for the second stage, the medium-temperature stage, for the large-scale evaporation of moisture in the film.

[0024] In this stage, the film is fed into the hot air box 1 through the feed port 12, guided by the guide roller 13, and then discharged from the discharge port 11. The discharged film undergoes imidization in the hot air box 1. As the film flows through the hot air box 1, hot air is blown out through the air outlet 21 and air outlet 22 on the hot air plate 2, blowing towards the upper and lower surfaces of the film, so that the upper and lower surfaces of the film are heated at the same time, increasing the uniformity of the film heating. The moisture in the film is evaporated by the heat, and then discharged from the hot air box 1 through the exhaust mechanism 3 with the hot air. The film is heated in the hot air box 1 until the moisture evaporates, thus achieving the imidization of the film.

[0025] Each hot air plate 2 has a connecting pipe 23 installed on its outer end for connecting to a hot air blower. In this utility model, the hot air plate 2 is connected to the hot air blower (not shown in the figure) through the connecting pipe 23. The hot air blower provides a hot air source. When the hot air enters the cavity of the hot air plate 2, it is discharged from the air outlet 21 and the air outlet 22 and blown towards the upper and lower end faces of the film. The air outlet 21 and the air outlet 22 are provided in multiple sets along the flow direction of the film, so that the hot air can be blown evenly onto the film.

[0026] Please see Figure 3 As shown, the exhaust mechanism 3 includes an exhaust duct 31 that is connected to the hot air box 1. An exhaust fan 32 is rotatably installed inside the exhaust duct 31. A drive motor 33 is connected to the rotating shaft of the exhaust fan 32. A connecting cover 34 is installed at the outer end of the exhaust duct 31. A connecting pipe 35 is connected to the connecting cover 34. In this application, the main function of the exhaust mechanism 3 is to accelerate the discharge of hot air and water vapor from the hot air box 1 and to guide the discharge of hot air and water vapor. Specifically, when imidizing the film, the drive motor 33 can be turned on, and the drive motor 33 drives the exhaust fan 32. The exhaust fan 32 draws the hot air and water vapor in the hot air box 1 into the exhaust duct 31, and then through the exhaust duct 31 and the connecting cover 34 into the connecting pipe 35. Finally, the exhaust gas is discharged into the cooling mechanism 4 through the connecting pipe 35 to achieve exhaust gas discharge. Importantly, exhaust mechanisms 3 are provided at the upper and lower ends of the hot air box 1, so that the water vapor evaporated on the upper surface of the film is discharged through the exhaust mechanism 3 at the upper end of the hot air box 1, and the water vapor evaporated on the lower surface of the film is discharged through the exhaust mechanism 3 at the lower end of the hot air box 1. This ensures that the water vapor evaporated from the film will not come into contact with the film again, and makes the moisture of the film evaporate more evenly.

[0027] Please see Figure 4 As shown, the cooling mechanism 4 includes a cooling box 41. An air inlet pipe 42 and an exhaust pipe 43 are respectively installed on the upper end of the cooling box 41. Two liquid level sensors 44 and 45 of different heights are installed on the side wall of the cooling box 41. A cooling pipe 47 is installed at the bottom of the interior of the cooling box 41. A drain pipe 48 is installed at the lower end of the cooling box 41. A control valve 49 is installed on the drain pipe 48. A heat dissipation fin 46 is also provided on the outer wall of the cooling box 41. The height of the liquid level sensor 44 is lower than the height of the liquid level sensor 45. The lowest end of the air inlet pipe 42 is lower than the measuring position of the liquid level sensor 44. The lowest end of the exhaust pipe 43 is higher than the measuring position of the liquid level sensor 45. The connecting pipe 35 is connected to the upper port of the air inlet pipe 42. The cooling mechanism 4 in this device is mainly used to cool and condense the moisture contained in the exhaust gas discharged from the hot air box 1 and store it in the cooling box 41 in the cooling mechanism 4, thereby reducing the moisture content in the exhaust gas and preventing the exhaust gas from remaining in the pipeline when it is discharged through the pipeline and affecting the operation of other equipment. Specifically, the exhaust gas discharged from the hot air box 1 enters the cooling box 41 through the connection of the connecting pipe 35 and the air inlet pipe 42. The exhaust gas is cooled in the cooling box 41, causing the water vapor in the exhaust gas to condense and remain in the cooling box 41. The exhaust gas is then discharged from the exhaust pipe 43. In this practical application, the cooling mechanism 4 always contains water, and the water level is always maintained between the level sensor 1 44 and the level sensor 2 45. This way, when the exhaust gas is sent into the cooling tank 41 through the air inlet pipe 42, it first comes into contact with the water in the cooling tank 41. As the exhaust gas rises from the bottom, it fully contacts the water, allowing the water vapor in the exhaust gas to be condensed more fully. When the water vapor condenses and accumulates in the cooling tank 41, it causes the water level to rise. When the water level rises to the level sensor 2 45, the level sensor 2 45 detects this and sends a signal to the controller. The controller then controls the control valve 49 to open, and water is discharged from the drain pipe 48. When the water level reaches the level sensor 1 44, the level sensor 1 44 detects this and sends a signal to the controller. The controller then controls the control valve 49 to close, stopping the drainage. This cycle repeats continuously, ensuring that the water level in the cooling tank 41 is always maintained between the level sensor 1 44 and the level sensor 2 45. In addition, in order to dissipate the heat of the water in the cooling tank 41, heat dissipation fins 46 are installed on the outer wall of the cooling tank 41 to play a cooling role. When the heat of the water in the cooling tank 41 is difficult to dissipate through the heat dissipation fins 46 alone, the cooling equipment can be turned on to make the coolant in the cooling equipment flow in the cooling pipe 47 to accelerate the cooling of the water in the cooling tank 41.

[0028] In this application, the control valve 49, drive motor 33, liquid level sensor 44, and the control and connection of the liquid level sensor 44 are all controlled by a controller (not shown in the figure). The connection and control between the controller and the above-mentioned devices are existing technologies and will not be described in detail here.

[0029] The working principle of this utility is as follows: When imidizing the film, the film is fed into the hot air box 1 through the feed port 12, guided by the guide roller 13, and then discharged from the discharge port 11. The discharged film is imidized in the hot air box 1. As the film flows through the hot air box 1, hot air is blown out through the air outlet 21 and air outlet 22 on the hot air plate 2, blowing towards the upper and lower surfaces of the film, so that the upper and lower surfaces of the film are heated at the same time, increasing the uniformity of the film heating. The moisture in the film is evaporated by the heat, and then discharged from the hot air box 1 through the exhaust mechanism 3 with the hot air. The film is heated in the hot air box 1 until the moisture evaporates, thus realizing the imidization of the film.

[0030] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the art.

Claims

1. A high-speed hot air device for polyimide film, characterized in that: Includes a hot air box (1) as a thin film reaction site, hot air plates (2) are installed on the left and right sides of the hot air box (1), the hot air plates (2) are hollow structures, and each hot air plate (2) is provided with a blower 1 (21) blowing towards the upper end of the film and a blower 2 (22) blowing towards the lower end of the film on the side facing the film. The hot air box (1) is equipped with exhaust mechanisms (3) at its upper and lower ends respectively. The exhaust mechanisms (3) are connected to the cooling mechanism (4) through the connecting pipe (35). The cooling mechanism (4) is located on one side of the hot air box (1).

2. The high-speed hot air device for polyimide film according to claim 1, characterized in that: The hot air box (1) has an inlet (12) for entering the film and an outlet (11) for discharging the film at its two ends. The inner sides of the hot air box (1) are equipped with guide rollers (13) that guide the film.

3. The high-speed hot air device for polyimide film according to claim 1, characterized in that: Each of the hot air plates (2) has a connecting pipe (23) installed on its outer end for connecting to the hot air blower.

4. The high-speed hot air device for polyimide film according to claim 1, characterized in that: The exhaust mechanism (3) includes an exhaust duct (31) connected to the hot air box (1), an exhaust fan (32) is rotatably installed inside the exhaust duct (31), a drive motor (33) is connected to the shaft of the exhaust fan (32), a connecting cover (34) is installed at the outer end of the exhaust duct (31), and a connecting pipe (35) is connected to the connecting cover (34).

5. The high-speed hot air device for polyimide film according to claim 1, characterized in that: The cooling mechanism (4) includes a cooling box (41), an air inlet pipe (42) and an exhaust pipe (43) are respectively installed on the upper end of the cooling box (41), two liquid level sensors (44) and (45) at different heights are installed on the side wall of the cooling box (41), a cooling pipe (47) is installed at the bottom inside the cooling box (41), a drain pipe (48) is installed at the lower end of the cooling box (41), a control valve (49) is installed on the drain pipe (48), and a heat dissipation fin (46) is also provided on the outer wall of the cooling box (41).

6. The high-speed hot air device for polyimide film according to claim 5, characterized in that: The height of the first liquid level sensor (44) is lower than the height of the second liquid level sensor (45), and the lowest end of the air inlet pipe (42) is lower than the measuring position of the first liquid level sensor (44). The lowest end of the exhaust pipe (43) is higher than the measuring position of the second liquid level sensor (45). The second connecting pipe (35) is connected to the upper port of the air inlet pipe (42).

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