Coextrusion film cooling device

Abstract

The invention discloses a co-extrusion film cooling device, and relates to the technical field of co-extrusion film cooling. The device comprises a rack, a film blowing machine is fixedly mounted at the bottom of the rack, a film blowing cover is arranged at an outlet of the film blowing machine, an inner film blowing head is arranged in the film blowing cover, an exhaust pipe is arranged at the top of the inner film blowing head, and an upper clamping traction system is mounted at the top of the rack; and an outer cooling assembly is arranged in the rack. Through the arrangement of the spiral elastic support and the limiting control hose, the limiting control hose with the proper length is selected according to the film specification, when the internal pressure of the film bubble is suddenly reduced, according to the feedback of the film bubble radius detection sensor, the spiral radius of the spiral elastic support is reduced, the cooling plate and the film bubble are driven to operate differently, and the air flow is reduced; the pressure of cooling gas on the film bubbles is reduced, the bubble stabilizing pressure is reduced, the bubble stabilizing pressure can be adjusted in a self-adaptive mode, and collapse of the film bubbles caused by too small internal pressure and too large bubble stabilizing pressure is prevented.

Description

Technical Field

[0001] This invention relates to the field of co-extruded film cooling technology, and more specifically to a co-extruded film cooling device. Background Technology

[0002] Co-extrusion film technology refers to the process of simultaneously processing two or more different polymer materials through extrusion to form a multilayer film material. In the production of co-extruded films, the cooling system plays a crucial role. The design and operation of the cooling system directly affect the film's thickness uniformity, surface smoothness, and physical properties. Therefore, a stable co-extruded film cooling system is of great significance for improving the production efficiency and quality of the film material.

[0003] Currently, the commonly used cooling method for co-extruded films is the IBC (Intra-Bubble Cooling) system, a cooling technology applied in film extrusion processes, particularly for the production of co-extruded films, blown films, and other polymer film materials. The main characteristic of the IBC system is that it directly cools the molten state of the film from within through airflow or other cooling media, thereby achieving rapid cooling and stable film formation. When using a bubble cooling system, bubble stability is a major issue. Bubbles that are too large may lead to uneven cooling, while bubbles that are too small may not effectively remove heat. Precisely controlling the size and density of the bubbles is a significant design challenge. Currently, a common approach is to install multiple sets of bubble-stabilizing rollers on the outside of the bubble to adjust the bubble size. Patent publication number CN213947168U discloses a cooling device for a three-layer co-extrusion blown film machine. The arrangement of the bubble-stabilizing rollers is similar to the layout of the cooling rollers in the aforementioned patent. The disadvantages of using the aforementioned external cooling and bubble stabilization methods are as follows: Both the stabilizing roller and the cooling roller are horizontally positioned, meaning they are tangential to the film bubble. The contact point is typically only a portion of the film surface, causing the bubbles to tend towards polygonal shapes during stabilization. This results in uneven pressure on the film surface, easily leading to indentations and wrinkles. Furthermore, when the internal pressure of the film bubble suddenly decreases, the bubble's stability declines. Existing bubble stabilization systems control the stabilizing roller's inward movement too far, increasing the pressure on the bubble and further compromising its stability. The bubble may deform or collapse, and in severe cases, it may even completely collapse, affecting the normal operation of the blown film process and causing production stoppage. Simultaneously, the cooling roller can only cool a portion of the film surface, while other parts of the film remain at a higher temperature. Therefore, the temperature difference during cooling is significant, resulting in poor cooling and forming effects. Summary of the Invention

[0004] The purpose of this invention is to provide a co-extruded film cooling device to solve the above-mentioned problems.

[0005] To achieve the above objectives, the present invention specifically adopts the following technical solution: A co-extruded film cooling device includes a frame, a blown film machine is fixedly installed at the bottom of the frame, a blown film hood is provided at the outlet of the blown film machine, an inner blown film head is provided inside the blown film hood, an exhaust pipe is provided at the top of the inner blown film head, and an upper clamping traction system is installed at the top of the frame. The frame is internally equipped with an external cooling assembly, which includes an outer frame that can be raised and lowered within the frame. A membrane bubble radius detection sensor is installed at the bottom of the outer frame. An upper adjusting ring is rotatably mounted on the inner top of the outer frame, and a lower adjusting ring is rotatably mounted on the inner bottom of the outer frame. Several helical elastic supports are installed inside the upper and lower adjusting rings. Several rotating shafts are rotatably mounted inside the helical elastic supports. An installation head is installed on the inner side of the rotating shaft. The installation head can automatically maintain a horizontal position. A cooling plate is installed inside the installation head. Several spray holes are installed on the outer side of the cooling plate. A limit control hose is installed between the outer end of the rotating shaft and the cooling plate. The limit control hose rests on the upper surface of the helical elastic support.

[0006] Furthermore, a rectangular slide rod is provided at the outer end of the rotating shaft, and several outer rings are provided between the upper and lower adjusting rings. Rectangular sliding holes are provided inside the outer rings, the upper adjusting ring, and the lower adjusting ring, and the rectangular slide rod passes through the rectangular sliding holes.

[0007] Furthermore, the top and bottom of the outer ring are rotatably mounted with connecting rings, and the bottom of the upper adjusting ring and the top of the lower adjusting ring are rotatably mounted with connecting rings. Two sets of hinged connecting rods are connected between adjacent connecting rings.

[0008] Furthermore, quick-connect connectors are provided on the outer side of the rectangular slide bar and the outer side of the cooling plate, and the limit control hose connects the two sets of quick-connect connectors.

[0009] Furthermore, a cooling air pipe is provided on the outer side of the outer frame, and a connecting air pipe is provided at the end of the rectangular slide rod away from the mounting head. The connecting air pipe connects the cooling air pipe to the quick-connect connector on the rectangular slide rod, and the length of the connecting air pipe is greater than the straight-line length between the rectangular slide rod and the cooling air pipe.

[0010] Furthermore, an upper servo motor is fixedly installed on the top of the outer frame, and an upper drive wheel is fixedly installed on the output end of the upper servo motor. A lower servo motor is fixedly installed on the bottom of the outer frame, and a lower drive wheel is fixedly installed on the output end of the lower servo motor. An upper transmission gear ring is provided on the outer side of the upper adjusting ring, and a lower transmission gear ring is provided on the outer side of the lower adjusting ring. The upper drive wheel meshes with the upper transmission gear ring, and the lower drive wheel meshes with the lower transmission gear ring. The upper servo motor and the lower servo motor rotate in opposite directions.

[0011] Furthermore, the frame consists of three platforms, each with a through hole inside.

[0012] Furthermore, two sets of lifting hydraulic cylinders are fixedly installed on the top of the frame, and the outer frame is fixedly installed at the bottom of the telescopic ends of the two sets of lifting hydraulic cylinders and can pass through the through hole.

[0013] Furthermore, the inner wall of the limiting control hose is provided with a spiral tensile metal wire.

[0014] Furthermore, the upper surface of the spiral elastic support is arc-shaped.

[0015] The beneficial effects of this invention are as follows: 1. This invention uses a spiral distribution of cooling plates to externally cool the membrane bubble, thereby cooling and stabilizing it. The spirally distributed multiple sets of cooling plates can maintain a relatively consistent temperature in different areas of the membrane bubble during the cooling process, avoiding warping caused by excessively rapid cooling in one part, resulting in high cooling quality.

[0016] 2. This invention, through the synchronous counter-rotation of the upper and lower adjusting rings, can provide torsional force to the spiral elastic support. When the torsional force is increased, the spiral elastic support moves inward, the spiral radius decreases, and the number of spiral turns increases. Therefore, it can be applied to the cooling of membrane bubbles of different sizes, with a wide range of applications. At the same time, during the bubble stabilization process, the pressure on the membrane bubble can be adjusted by adjusting the spiral radius, and the pressure applied to the membrane bubble is used as spiral pressure, so that the membrane bubble can stably maintain a cylindrical shape and the film surface is uniformly pressurized.

[0017] 3. By maintaining a horizontal cooling plate, the present invention ensures that the cooling airflow is always directed vertically toward the film. During the bubble stabilization process, the cooling airflow direction will not change too much, resulting in uniform cooling and reducing the likelihood of wrinkles in the film, thus achieving high-quality bubble stabilization cooling.

[0018] 4. This invention, through the setting of a spiral elastic support and a limiting control hose, selects a suitable length of limiting control hose according to the membrane specifications. When the internal pressure of the membrane bubble suddenly decreases, based on feedback from the membrane bubble radius detection sensor, the spiral radius of the spiral elastic support decreases, causing the cooling plate and the membrane bubble to move differently. Since the number of spiral turns of the spiral elastic support increases within the same length, the horizontal inclination angle of the spiral decreases, that is, the horizontal angle between the cooling plate and the spiral elastic support decreases. At this time, the limiting control hose is subjected to tension and compression. The contact portion between the limiting control hose and the spiral elastic support is reduced through the cavity, thereby reducing the air flow rate, reducing the pressure of the cooling gas on the membrane bubble, and reducing the stabilizing pressure. This allows the stabilizing pressure to be adaptively adjusted, preventing the membrane bubble from collapsing due to excessively low internal pressure and excessively high stabilizing pressure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2This is a schematic diagram of the external cooling component structure of the present invention; Figure 3 This is a schematic diagram of the blown film machine structure of the present invention; Figure 4 This is an exploded structural diagram of the external cooling component of the present invention; Figure 5 This is a schematic diagram of the outer ring transmission structure of the present invention; Figure 6 This is a schematic diagram of the spiral elastic support structure of the present invention; Figure 7 This is a schematic diagram of the rectangular slide bar and cooling plate structure of the present invention; Figure 8 This is a schematic diagram of the limit control hose structure of the present invention.

[0020] Reference numerals: 1. Frame; 2. Blown film machine; 21. Blown film hood; 22. Inner blown film head; 23. Exhaust pipe; 3. Upper clamping traction system; 4. Lifting hydraulic cylinder; 5. Outer frame; 51. Cooling air pipe; 52. Upper servo motor; 53. Upper drive wheel; 54. Lower servo motor; 55. Lower drive wheel; 56. Bubble radius detection sensor; 6. Upper adjusting ring; 61. Upper transmission gear ring; 7. Lower adjusting ring; 71. Lower transmission gear ring; 8. Outer ring; 81. Rectangular sliding hole; 9. Connecting swivel; 10. Connecting rod; 11. Spiral elastic support; 12. Rectangular sliding rod; 13. Rotating shaft; 14. Mounting head; 15. Quick-connect connector; 16. Cooling plate; 161. Spray hole; 17. Limit control hose; 18. Connecting air pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0022] Example 1, as Figures 1-8 As shown, a co-extruded film cooling device includes a frame 1, a blown film machine 2 is fixedly installed at the bottom of the frame 1, a blown film hood 21 is provided at the outlet of the blown film machine 2, an inner blown film head 22 is provided inside the blown film hood 21, an exhaust pipe 23 is provided at the top of the inner blown film head 22, and an upper clamping traction system 3 is installed at the top of the frame 1. The frame 1 is equipped with an external cooling assembly, which includes an outer frame 5 that can be raised and lowered inside the frame 1. A membrane bubble radius detection sensor 56 is installed at the bottom of the outer frame 5. An upper adjusting ring 6 is rotatably installed at the top inner part of the outer frame 5, and a lower adjusting ring 7 is rotatably installed at the bottom inner part of the outer frame 5. Several spiral elastic supports 11 are installed inside the upper adjusting ring 6 and the lower adjusting ring 7. Several rotating shafts 13 are rotatably installed inside the spiral elastic supports 11. An installation head 14 is installed on the inner side of the rotating shaft 13. The installation head 14 can automatically keep horizontal. A cooling plate 16 is installed inside the installation head 14. Several spray holes 161 are installed on the outer side of the cooling plate 16. A limit control hose 17 is installed between the outer end of the rotating shaft 13 and the cooling plate 16. The limit control hose 17 rests on the upper surface of the spiral elastic support 11.

[0023] The inner wall of the limit control hose 17 is provided with spiral tensile metal wire to improve tensile strength, and the upper surface of the spiral elastic bracket 11 is arc-shaped to prevent scratching the limit control hose 17.

[0024] After the film enters the blown film machine 2, it is blown into a film bubble by the inner blown film head 22. The airflow is from bottom to top, and the hot airflow is blown upward and discharged through the exhaust pipe 23 for IBC film bubble cooling. However, the cooling efficiency of the IBC film bubble cooling system alone is not high enough. Therefore, an external cooling component is set on the outside of the film bubble to combine cooling and bubble stabilization.

[0025] External cooling airflow is ejected through nozzles 161 on cooling plate 16. The cooling airflow is horizontally directed towards the membrane bubble. Under the action of spiral elastic support 11, cooling plate 16 is spirally distributed, which can keep the temperature of each area of ​​the membrane bubble relatively uniform during the cooling process, avoid warping due to excessive cooling in one part, and achieve high cooling quality. At the same time, air pressure is used to apply bubble stabilization pressure to the membrane bubble, and the bubble stabilization pressure is distributed in a spiral circumference, so the membrane bubble is subjected to uniform force, making the membrane bubble state closer to a cylindrical shape, which can better maintain a stable shape and avoid unnecessary deformation.

[0026] During operation, the bubble radius detection sensor 56 (such as a laser sensor, infrared sensor, or vision system) monitors the diameter and shape of the bubble in real time. The real-time data provided by the sensor is received by the control system and used to calculate the size change of the bubble. The system continuously updates the position and adjustment requirements of the bubble stabilizing roller based on this data. After receiving the bubble size data, the control unit in the system (usually a PLC or embedded controller) calculates the optimal position of the bubble stabilizing roller using a preset control algorithm. Based on the changes in the bubble, the control unit controls the upper adjusting ring 6 and the lower adjusting ring 7 to rotate synchronously in opposite directions, applying or reducing the torsional force to the spiral elastic support 11. When the torsional force is reduced, the radius of the spiral elastic support 11 increases, and the spiral elastic support 11 moves away from the bubble through the mounting head 14 replacing the cooling plate 16; when the torsional force is increased, the radius of the spiral elastic support 11 decreases, and the spiral elastic support 11 moves closer to the bubble through the mounting head 14 replacing the cooling plate 16 for bubble stabilization adjustment. When the internal air pressure of the membrane bubble suddenly decreases, the torsional force increases. Since the height between the upper adjusting ring 6 and the lower adjusting ring 7 remains unchanged, at the same height, the radius of the spiral elastic support 11 decreases, the number of turns of the spiral elastic support 11 increases, and the spiral tilt angle decreases. Since the mounting head 14 drives the cooling plate 16 to always remain horizontal, the angle between the upper surface of the spiral elastic support 11 and the cooling plate 16 decreases. The cooling plate 16 drives the limit control hose 17 to swing downward relative to the spiral elastic support 11. The limit control hose 17 rests on the upper surface of the spiral elastic support 11, and the limit control hose 17 is subjected to tension and pressure. The contact position between the limit control hose 17 and the spiral elastic support 11 is flattened, which restricts the airflow and reduces the bubble stabilization pressure. This allows the bubble stabilization pressure to be adaptively adjusted, preventing the membrane bubble from collapsing due to excessively high bubble stabilization pressure caused by excessively low internal pressure.

[0027] Meanwhile, the present invention, through the setting of the spiral elastic support 11, can automatically adjust the outer cooling radius according to the size of the membrane bubble, and has a wide range of applications. It should be noted that during the range adjustment process, the limit control hose 17 is not installed first, and is installed after the adjustment is completed. The telescopic length of the limit control hose 17 is selected according to the pressure regulation range. The advantage of this design is that when the internal air pressure of the membrane bubble is too low, far exceeding the pressure regulation range, if it is not controlled, the cooling plate 16 will be excessively gathered, which can easily cause the membrane bubble to be excessively squeezed and folded together, causing a greater safety accident. Therefore, when it is far beyond the pressure regulation range, the limit control hose 17 cannot be stretched under the action of the spiral tensile metal wire, thereby limiting the spiral elastic support 11 from continuing to shrink, preventing excessive compression, and improving the overall system operation stability.

[0028] In the second embodiment, based on the above embodiment, a rectangular slide rod 12 is provided at the outer end of the rotating shaft 13, and a plurality of outer rings 8 are provided between the upper adjusting ring 6 and the lower adjusting ring 7. A rectangular sliding hole 81 is provided through the interior of the outer ring 8, the upper adjusting ring 6 and the lower adjusting ring 7, and the rectangular slide rod 12 passes through the rectangular sliding hole 81.

[0029] The top and bottom of the outer ring 8 are rotatably mounted with connecting rings 9, and the bottom of the upper adjusting ring 6 and the top of the lower adjusting ring 7 are rotatably mounted with connecting rings 9. Two sets of hinged connecting rods 10 are connected between adjacent connecting rings 9.

[0030] The upper adjusting ring 6 and the lower adjusting ring 7 drive the spiral elastic bracket 11 to rotate via the rectangular slide rod 12. The spiral elastic bracket 11 drives the cooling plate 16 to rotate synchronously. Since the hinged connecting rods 10 are distributed in at least three sets of rings between adjacent connecting rotating rings 9 and swing in the rectangular hinge groove, the adjacent connecting rotating rings 9 will stably maintain a horizontal state when rising and falling. The connecting rotating rings 9 can keep the outer ring 8 in a horizontal state when rising and falling and can rotate on the horizontal plane. Therefore, under the action of the rectangular slide rod 12, the outer ring 8 rotates synchronously and causes the rectangular slide rods 12 on multiple sets of spiral elastic brackets 11 to rotate at the same angle, always located on the same plane, improving the deformation stability of the spiral elastic bracket 11. At the same time, since the outer ring 8 always remains in a horizontal state, the rectangular slide rod 12 always remains in a horizontal state, and the rectangular slide rod 12 keeps the mounting head 14 always in a horizontal state. Through the setting of this embodiment, while ensuring the stable deformation of several spiral elastic brackets 11, the mounting head 14 can always remain in a horizontal state without additional complex control, and the structure is simple.

[0031] In embodiment three, based on the above embodiments, quick-connect couplings 15 are provided on the outer side of the rectangular slide bar 12 and the outer side of the cooling plate 16, and the limit control hose 17 connects the two sets of quick-connect couplings 15. The quick-connect couplings 15 allow for quick disassembly and connection of the limit control hose 17.

[0032] Example 4, based on the above examples, further includes a cooling air pipe 51 provided on the outer side of the outer frame 5, and a connecting air pipe 18 provided at the end of the rectangular slide rod 12 away from the mounting head 14. The connecting air pipe 18 connects the cooling air pipe 51 to the quick connector 15 on the rectangular slide rod 12, and the length of the connecting air pipe 18 is greater than the straight length between the rectangular slide rod 12 and the cooling air pipe 51.

[0033] External cooling gas enters the connecting pipe 18 through the cooling pipe 51, then enters the cooling plate 16 through the limit control hose 17, and finally is ejected through the nozzle 161. The connecting pipe 18 does not affect the sliding of the rectangular slide bar 12 relative to the outer ring 8.

[0034] Example 5, based on the above examples, further includes: an upper servo motor 52 fixedly mounted on the top of the outer frame 5; an upper drive wheel 53 fixedly mounted on the output end of the upper servo motor 52; a lower servo motor 54 fixedly mounted on the bottom of the outer frame 5; a lower drive wheel 55 fixedly mounted on the output end of the lower servo motor 54; an upper transmission gear ring 61 provided on the outer side of the upper adjusting ring 6; a lower transmission gear ring 71 provided on the outer side of the lower adjusting ring 7; the upper drive wheel 53 meshes with the upper transmission gear ring 61; the lower drive wheel 55 meshes with the lower transmission gear ring 71; and the upper servo motor 52 and the lower servo motor 54 rotate in opposite directions.

[0035] By controlling the synchronous reverse rotation of the upper servo motor 52 and the lower servo motor 54, the upper servo motor 52 and the lower servo motor 54 drive the upper adjusting ring 6 and the lower adjusting ring 7 to rotate through the upper transmission gear ring 61 and the lower transmission gear ring 71 respectively, resulting in high servo motor control precision.

[0036] Example 6, based on the above examples, further includes a frame 1 consisting of three platforms, each with internal through-holes. The platforms and through-holes facilitate the inspection and replacement of external cooling components.

[0037] Two sets of lifting hydraulic cylinders 4 are fixedly installed on the top of the frame 1, and the outer frame 5 is fixedly installed at the bottom of the telescopic ends of the two sets of lifting hydraulic cylinders 4 and can pass through the through hole.

[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A co-extruded film cooling device, comprising a frame (1), characterized in that, A blown film machine (2) is fixedly installed at the bottom of the frame (1). A blown film hood (21) is provided at the outlet of the blown film machine (2). An inner blown film head (22) is provided inside the blown film hood (21). An exhaust pipe (23) is provided at the top of the inner blown film head (22). An upper clamping traction system (3) is installed at the top of the frame (1). The frame (1) is equipped with an external cooling assembly, which includes an outer frame (5) that can be raised and lowered inside the frame (1). A membrane bubble radius detection sensor (56) is provided at the bottom of the outer frame (5). An upper adjusting ring (6) is rotatably installed at the top inner part of the outer frame (5), and a lower adjusting ring (7) is rotatably installed at the bottom inner part of the outer frame (5). Several spiral elastic supports (11) are provided inside the upper adjusting ring (6) and the lower adjusting ring (7). Several rotating shafts (13) are rotatably installed inside the spiral elastic supports (11). An installation head (14) is provided on the inner side of the rotating shaft (13). The installation head (14) can automatically maintain a horizontal position. A cooling plate (16) is provided inside the installation head (14). Several spray holes (161) are provided on the outer side of the cooling plate (16). A limit control hose (17) is provided between the outer end of the rotating shaft (13) and the cooling plate (16). The limit control hose (17) rests on the upper surface of the spiral elastic support (11).

2. The co-extruded film cooling device according to claim 1, characterized in that, A rectangular slide rod (12) is provided at the outer end of the rotating shaft (13). Several outer rings (8) are provided between the upper adjusting ring (6) and the lower adjusting ring (7). A rectangular sliding hole (81) is provided through the interior of the outer ring (8), the upper adjusting ring (6) and the lower adjusting ring (7). The rectangular slide rod (12) passes through the rectangular sliding hole (81).

3. The co-extruded film cooling device according to claim 2, characterized in that, The top and bottom of the outer ring (8) are rotatably mounted with connecting rings (9), and the bottom of the upper adjusting ring (6) and the top of the lower adjusting ring (7) are rotatably mounted with connecting rings (9). Two sets of connecting rods (10) are hinged between adjacent connecting rings (9).

4. A co-extruded film cooling device according to claim 3, characterized in that, The outer side of the rectangular slide bar (12) and the outer side of the cooling plate (16) are both provided with quick-connect connectors (15), and the limit control hose (17) connects the two sets of quick-connect connectors (15).

5. A co-extruded film cooling device according to claim 4, characterized in that, A cooling air pipe (51) is provided on the outer side of the outer frame (5). A connecting air pipe (18) is provided at the end of the rectangular slide rod (12) away from the mounting head (14). The connecting air pipe (18) connects the cooling air pipe (51) to the quick connector (15) on the rectangular slide rod (12). The length of the connecting air pipe (18) is greater than the straight length between the rectangular slide rod (12) and the cooling air pipe (51).

6. A co-extruded film cooling device according to claim 1, characterized in that, An upper servo motor (52) is fixedly installed on the top of the outer frame (5), and an upper drive wheel (53) is fixedly installed on the output end of the upper servo motor (52). A lower servo motor (54) is fixedly installed on the bottom of the outer frame (5), and a lower drive wheel (55) is fixedly installed on the output end of the lower servo motor (54). An upper transmission gear ring (61) is provided on the outer side of the upper adjusting ring (6), and a lower transmission gear ring (71) is provided on the outer side of the lower adjusting ring (7). The upper drive wheel (53) meshes with the upper transmission gear ring (61), and the lower drive wheel (55) meshes with the lower transmission gear ring (71). The upper servo motor (52) and the lower servo motor (54) rotate in opposite directions.

7. A co-extruded film cooling device according to claim 1, characterized in that, The frame (1) consists of three platforms, each with a through hole inside.

8. A co-extruded film cooling device according to claim 7, characterized in that, Two sets of lifting hydraulic cylinders (4) are fixedly installed on the top of the frame (1), and the outer frame (5) is fixedly installed at the bottom of the telescopic ends of the two sets of lifting hydraulic cylinders (4) and can pass through the through hole.

9. A co-extruded film cooling device according to claim 1, characterized in that, The inner wall of the limit control hose (17) is provided with a spiral tensile metal wire.

10. A co-extruded film cooling device according to claim 1, characterized in that, The upper surface of the spiral elastic support (11) is arc-shaped.

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