A tunnel for reducing the longitudinal shrinkage of a film

Abstract

The present application belongs to the technical field of lithium battery separator production line, and specifically relates to a drying room device for reducing longitudinal shrinkage of a film, which comprises a drying room, guide rollers, pressure rollers, expansion rollers, a supplementary air exhaust system and a cooling structure; the drying room is provided with a film inlet and a film outlet at two ends respectively; the guide rollers are used for guiding the movement of the film in the drying room; the pressure rollers are installed at the periphery of the guide rollers, and the pressure rollers press the film against the guide rollers to keep the film flat; the expansion rollers are distributed along the movement track of the film in the drying room; the expansion rollers are used for preventing the film from shrinking transversely after being heated; the supplementary air exhaust system is connected with the drying room and is used for adjusting the temperature in the drying room; and the cooling structure is arranged behind the film outlet of the drying room and is used for cooling and setting the film heated in the drying room. The drying room device can effectively reduce the longitudinal shrinkage of the finished film through heat preservation in the drying room and cooling and setting of the cooling roller, so that the longitudinal heat shrinkage rate of the finished film meets the production requirements.

Description

Technical Field

[0001] This invention belongs to the technical field of lithium battery separator production line, specifically a drying oven device for reducing longitudinal shrinkage of thin films. Background Technology

[0002] In lithium battery separator production lines, the average longitudinal thermal shrinkage rate of finished films is relatively high. Customers hope to reduce the longitudinal thermal shrinkage of finished films. To achieve this goal, heating rollers are used in existing production lines to heat the film. The heated film will shrink back, allowing the film to shrink longitudinally during the intermediate stage of production. After the film has shrunk, the longitudinal thermal shrinkage rate of the finished film will be reduced, thus meeting the customer's requirements.

[0003] The existing production line uses multiple heating rollers for production, but the effect is not ideal. Because the heating rollers only heat the film that is in contact with the rollers, the film between the heating rollers cannot be heated, resulting in uneven heating of the film and wrinkles on the film surface. The higher the temperature of the heating rollers, the more obvious the wrinkles become.

[0004] Therefore, it is of great significance to develop a drying oven device that reduces longitudinal shrinkage of the film in order to solve the problems that arise in the above production process. Summary of the Invention

[0005] This invention provides a drying oven device to reduce longitudinal shrinkage of thin films, thereby solving problems such as high longitudinal thermal shrinkage rate and film wrinkles in existing equipment in lithium battery separator production, and improving the quality of finished films.

[0006] To achieve the above objectives, the present invention adopts the following specific technical solution: a drying oven device for reducing longitudinal shrinkage of film, comprising a drying oven, guide rollers, pressure rollers, extension rollers, a supplementary and exhaust air system, and a cooling structure;

[0007] The drying chamber has a film inlet and a film outlet at both ends; a support wall plate is fixed on the side wall inside the drying chamber; the guide roller, pressure roller and extension roller are all installed parallel to each other on the support wall plate;

[0008] There are several guide rollers, which are driven to rotate by a drive motor to guide the movement of the film in the drying chamber.

[0009] There are several pressure rollers, which are installed around the periphery of the guide rollers. The pressure rollers press the film firmly onto the guide rollers to keep the film flat.

[0010] There are several extension rollers, which are distributed along the movement trajectory of the film in the drying oven; used to prevent the film from shrinking laterally after heating.

[0011] The air supply and exhaust system is connected to the drying chamber and is used for temperature regulation within the drying chamber.

[0012] The cooling structure is located behind the film outlet of the drying chamber to cool and shape the film that has been heated in the drying chamber.

[0013] Furthermore, the air supply and exhaust system includes an external fan, a static pressure box, and air ducts;

[0014] The external fan is located outside the drying chamber; the external fan is connected to the static pressure box via an air duct; the external fan has a heating function and can control the temperature inside the drying chamber.

[0015] There are several static pressure boxes, which are respectively set on the upper and lower sides inside the drying room; the static pressure boxes are connected to the air ducts so that the air can be evenly distributed to all parts of the drying room.

[0016] Furthermore, the pressure roller is mounted on a moving device; the moving device is installed on a supporting wall plate; the position of the pressure roller can be adjusted by the moving device to move closer to or further away from the guide roller.

[0017] Furthermore, multiple cooling rollers are arranged parallel to each other within the cooling structure;

[0018] The cooling roller is a hollow cylindrical structure containing coolant, used to cool and shape the film after it has been heated in the drying oven.

[0019] Furthermore, the drying room includes a frame and insulation boards; the insulation boards are laid on the frame to provide insulation.

[0020] The present invention has the following advantages and effects:

[0021] The drying oven apparatus of the present invention can effectively reduce the longitudinal shrinkage of the finished film by means of heat preservation treatment in the drying oven and cooling and shaping by cooling rollers, so that the longitudinal thermal shrinkage rate of the finished film meets the production requirements.

[0022] The drying chamber apparatus of the present invention can provide a constant and uniform temperature field, enabling the film to be heat-preserved at a uniform temperature. Compared with traditional heating rollers, the drying chamber of the present invention can better control the temperature of the film and reduce the impact of temperature fluctuations on the film quality.

[0023] The arrangement of the pressure roller and the spreading roller in this invention effectively prevents wrinkling and lateral shrinkage of the film during production, improving the film's flatness and dimensional stability. This helps improve the quality of the finished film and reduce the defect rate. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the drying room apparatus disclosed in this invention;

[0025] In the picture:

[0026] 1. Cooling roller; 2. Extending roller; 3. Drying oven; 4. Static pressure box; 5. Pressure roller; 6. Guide roller; 7. Support wall panel. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0028] Based on the problems encountered in the existing production process, the drying oven device developed in this invention replaces the heating rollers of the existing production line with guide rollers, and designs the drying oven device to maintain a constant heat preservation environment for the film, rather than simply relying on the heating rollers to heat the film. The existing heating rollers only heat the film on the heating rollers, while the film between the rollers cannot be kept warm. Moreover, the local high temperature of the heating rollers will cause serious shrinkage deformation and wrinkling problems to the film.

[0029] refer to Figure 1 A drying chamber device for reducing longitudinal shrinkage of film includes a drying chamber 3, guide rollers 6, pressure rollers 5, extension rollers 2, a supplementary and exhaust air system, and a cooling structure.

[0030] The drying chamber 3 has a film inlet and a film outlet at both ends. As an insulation structure, the drying chamber 3 keeps the film warm for a certain period of time, causing the film inside the drying chamber 3 to shrink longitudinally due to heat, thus reducing the longitudinal thermal shrinkage of the finished product. A support wall plate 7 is fixed on the side wall inside the drying chamber 3. The support wall plate 7 is a plate-shaped structure with a certain thickness and strength, used to provide support and fixation for components such as the guide roller 6, pressure roller 5, and extension roller 2. The guide roller 6, pressure roller 5, and extension roller 2 are all installed parallel to each other on the support wall plate 7.

[0031] In this embodiment, there are six guide rollers 6, arranged alternately on the upper and lower sides. The guide rollers 6 are driven to rotate by a drive motor and are rotatably mounted on the support wall plate 7 via bearing seats. After the film enters the drying chamber 3 through the film inlet, it sequentially passes over each guide roller 6. The film contacts the surface of the guide roller 6 and changes its direction of movement under its influence. Driven by the guide rollers 6, the film can move smoothly along a preset trajectory, achieving a continuous production process. During the film's movement along the guide rollers 6, the precise control of the guide rollers 6 by the drive motor allows the film's conveying speed and tension to be adjusted according to production needs, thereby better controlling the film's longitudinal shrinkage and internal stress, ensuring the film's quality and stability.

[0032] Multiple pressure rollers 5 can be set according to production conditions. In this embodiment, there are five pressure rollers 5, and each pressure roller 5 is matched with a guide roller 6. The pressure roller 5 is installed on one side of the guide roller 6, and the position of the pressure roller 5 can be adjusted according to the actual thickness of the film. The pressure roller 5 can effectively press the film onto the guide roller 6, so that the film remains flat during the heating process, thereby improving the quality of the film.

[0033] Multiple extension rollers 2 can be set according to production conditions and distributed along the movement trajectory of the film in the drying chamber 3. In this embodiment, there are four extension rollers 2, which are respectively installed at the film inlet and film outlet positions and between two adjacent guide rollers 6. During the film conveying process, due to the increase in temperature, the film is prone to lateral shrinkage in addition to longitudinal shrinkage. By installing extension rollers 2 between the guide rollers 6, the film can be clamped, effectively preventing lateral shrinkage of the film after heating and improving the dimensional stability of the film.

[0034] Furthermore, to better adapt to the characteristics and production requirements of different films, the pressure and tension of the spreading roller 2 can be adjusted. By adjusting the position of the spreading roller 2, the clamping force of the spreading roller 2 on the film can be changed to achieve the best anti-lateral shrinkage effect. It should be noted that the spreading roller 2 is an existing structure, and its working principle and structure will not be described in detail in this application.

[0035] The exhaust and replenishment air system has a heating function for temperature regulation inside the drying chamber 3, and for keeping the film warm for a certain period of time.

[0036] The cooling structure is located behind the film outlet of the drying chamber 3 to cool and shape the film that has been heated by the drying chamber 3.

[0037] Furthermore, the air supply and exhaust system includes an external fan, a static pressure box 4, and air ducts;

[0038] An external fan is installed outside the drying chamber 3; the external fan is connected to the static pressure box 4 through an air duct; the external fan has a heating function, which can precisely control the temperature inside the drying chamber 3, and set appropriate heat preservation temperature and time according to the material characteristics and production requirements of the film, so as to ensure that the film is processed at a constant temperature and reduce the impact of temperature fluctuations on the heat shrinkage rate.

[0039] Multiple static pressure boxes 4 can be set according to production conditions. In this embodiment, there are eight static pressure boxes 4, which are divided into two groups and set on the upper and lower sides of the drying chamber 3 respectively. The static pressure box 4 is used to stabilize and equalize the air delivered by the air duct, so that the air can be evenly distributed to various parts of the drying chamber 3, ensuring that the air field in the drying chamber 3 is uniform and that the film can be evenly heated.

[0040] Furthermore, the pressure roller 5 is mounted on the moving device; the moving device is mounted on the supporting wall plate 7; the position of the pressure roller 5 can be adjusted by the moving device to move closer to or further away from the guide roller 6, and the position can be adjusted according to the actual thickness of the film. Since the film is prone to wrinkles during heating and conveying, the pressure roller 5 can be used to effectively press the film, ensuring the flatness and tension consistency of the film, thereby improving the quality of the film.

[0041] Furthermore, multiple cooling rollers 1 are arranged parallel to each other within the cooling structure; the film passes around the multiple cooling rollers 1 in sequence and connects with the cooling rollers 1.

[0042] The cooling roller 1 is a hollow cylindrical structure with a smooth surface. The interior of the cooling roller 1 has flow channels containing cooling water. The main function of the cooling roller 1 is to cool and set the film after it has undergone heat treatment in the drying chamber 3. After passing through the drying chamber 3, the film has a high temperature and significant internal stress. The cooling effect of the cooling roller 1 allows the film to cool down rapidly, thus achieving film cooling and setting.

[0043] Furthermore, the drying chamber 3 includes a frame and insulation panels; the insulation panels, laid on the frame, provide insulation. This allows the drying chamber 3 to provide a constant and uniform temperature field, enabling the film to maintain its heat-insulating state for a certain period of time, thereby achieving a certain degree of longitudinal shrinkage. The insulation panels inside the drying chamber 3 can effectively reduce heat loss and maintain a stable temperature inside the drying chamber 3.

[0044] Working principle:

[0045] The external air supply system is activated, and air is supplied to the static pressure box 4 through the air duct. The static pressure box distributes the air evenly into the drying room 3, forming a constant and uniform temperature field.

[0046] Start the drive motor of guide roller 6, and adjust the film conveying speed and tension according to production needs to make the film pass smoothly through the drying room 3 for heat preservation treatment.

[0047] During the process of the film passing through the drying chamber 3, the pressure roller 5 and the spreading roller 2 device play a role in preventing the film from wrinkling and lateral shrinkage.

[0048] After being heated in the drying oven 3, the film enters the cooling roller 1, where it is cooled and shaped to reduce longitudinal shrinkage and internal stress.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0051] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A tunnel apparatus for reducing the longitudinal shrinkage of a film, characterized in that, It comprises a drying room (3), a guide roller (6), a pressure roller (5), an expansion roller (2), a complementary air exhaust system and a cooling structure. The drying room (3) is provided with a film inlet and a film outlet at two ends respectively; a support wallboard (7) is fixed on the side wall inside the drying room (3); the guide roller (6), the pressure roller (5) and the expansion roller (2) are all installed on the support wallboard (7) in parallel. The guide roller (6) has several guide rollers, which are driven to rotate by a driving motor and used to guide the movement of the film in the drying room (3). The pressure roller (5) has several pressure rollers, which are installed at the peripheral position of the guide roller (6) and press the film tightly on the guide roller (6) to keep the film flat. The expansion roller (2) has several expansion rollers, which are distributed along the movement track of the film in the drying room (3) and used to prevent the film from shrinking transversely after being heated. The complementary air exhaust system is connected with the drying room (3) and used for temperature adjustment in the drying room (3). The cooling structure is arranged behind the film outlet of the drying room (3) and used to cool and shape the film heated in the drying room (3). The cooling structure is provided with a plurality of cooling rollers (1) in parallel. The cooling roller (1) is a hollow cylindrical structure with cooling liquid inside and used to cool and shape the film after heat preservation in the drying room (3). The expansion roller (2) has four expansion rollers, which are distributed along the movement track of the film in the drying room (3) and installed at the positions of the film inlet and the film outlet and between the adjacent two guide rollers (6). The pressure and tension of the expansion roller (2) can be adjusted.

2. The oven apparatus for reducing longitudinal take-up of a film according to claim 1, wherein, The complementary air exhaust system comprises an external fan, a static pressure tank (4) and an air pipe. The external fan is arranged outside the drying room (3) and connected with the static pressure tank (4) through the air pipe; the external fan has a heating function and can control the temperature in the drying room (3). The static pressure tank (4) has several static pressure tanks and is arranged on the upper and lower sides inside the drying room (3); the static pressure tank (4) is connected with the air pipe to make the air evenly distributed to each part in the drying room (3).

3. The oven apparatus for reducing longitudinal take-up of a film according to claim 2, wherein, The pressure roller (5) is arranged on a moving device, which is installed on the support wallboard (7); the position of the pressure roller (5) can be adjusted by the moving device to approach or move away from the guide roller (6).

4. The oven apparatus for reducing longitudinal take-up of a thin film according to claim 1, wherein The drying room (3) comprises a frame and a heat preservation plate, which is laid on the frame to play a heat preservation role.

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