A low-permeability film casting production line

Abstract

The present invention discloses a low-permeability film cast molding production line, which relates to the field of plastic processing. The low-permeability film cast molding production line provided by the present solution has carried out directional defect optimization for stretching. Through the combination of a differential component and a uniform speed component, the stretching speed and temperature change of the film body during heating stretching and cooling shaping can be accurately controlled, thereby ensuring the uniformity of the film thickness and the stability of the mechanical properties. At the same time, the cooling shaping component uniformly cools the film by step-by-step cooling to prevent the film body from adhesion or deformation due to uneven stress after cooling. During the shutdown process, the state limiting component can effectively prevent the film from reverse pulling and breaking, thereby ensuring safety and production continuity after shutdown. In addition, the automatic tension control function of the equipment ensures that the tensile stress of the film is effectively relieved under various working conditions, thereby greatly improving the efficiency of film production and product quality.

Description

Technical Field

[0001] The invention relates to the field of plastic processing, in particular to a low-air-permeability film casting production line. Background Art

[0002] Existing low-permeability films are widely used in food packaging, medical dressings, building waterproofing materials, and other fields. Their primary function is to provide a certain barrier property, preventing the penetration of air or water vapor, thereby extending the product's service life or maintaining the freshness of the packaged contents. However, traditional low-permeability films are typically produced using a blown film process. While this process offers certain cost advantages, it has significant limitations in terms of film thickness uniformity, permeability control, and production efficiency. The blown film process can easily lead to uneven film thickness and low tensile strength, which directly affects the film's physical properties. This is particularly true in applications requiring high durability and barrier properties, making it unable to meet stringent quality requirements.

[0003] In order to improve the production quality and performance of low-permeability films, the tape casting process has been gradually introduced. In the tape casting process, after the raw materials are melted by an extruder, the melt is evenly extruded through a die head to form a film, and then the finished product is obtained through steps such as cooling and stretching. Compared with the traditional blown film process, the tape casting process can achieve more precise film thickness control, and the physical properties of the film are significantly improved, especially in terms of air permeability, tensile strength, thickness uniformity, etc. It has obvious advantages. In addition, the tape casting process has a fast production speed and a high degree of automation, which is suitable for large-scale production and can effectively improve production efficiency and product quality. However, in the tape casting process of low-permeability films, there are still problems such as low stretching control accuracy, insufficient film thickness consistency, and poor coordination between production line equipment, resulting in a low yield rate, which limits the further promotion of the tape casting process.

[0004] In traditional low-permeability film cast molding production lines, the film is usually stretched after being heated by a heating roller, but this method has several disadvantages. First, the temperature control of the heating roller is difficult to control accurately. Once the temperature fluctuates greatly, the film will be stretched unevenly, affecting the thickness consistency and physical properties of the film. Too high a temperature may cause local over-stretching or over-softening of the film, reducing its strength and durability; while too low a temperature will lead to insufficient stretching and insufficient film strength and ductility. In addition, during the cooling and winding process of the film after the heating roller, local stress concentration may occur due to the rapid stretching after being heated, which increases the risk of film breakage during the production process, especially when the stretch ratio is high.

[0005] Furthermore, when current equipment is shut down due to component damage or power outages after prolonged operation, the film is often left in a stretched state. This high stress concentration in the film during stretching, coupled with temperature changes or equipment inertia during the shutdown process, can easily lead to film breakage. This not only wastes raw materials but also increases debugging time when restarting production, reducing production efficiency. Furthermore, when traditional production lines are shut down, film tension is difficult to effectively control. This is especially true when the stretching rollers and winding system are not adjusted synchronously. This can cause reverse pull on the film, resulting in uneven stress on the film and further increasing the likelihood of breakage. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem that low-permeability films are easily broken during the stretching process of traditional production lines, and to propose a low-permeability film casting production line.

[0007] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: a low-permeability film cast molding production line, comprising a low-permeability film cast molding production line consisting of a screw extruder, a casting machine, a cooling device, a stretching machine, a cutting mechanism and a winding machine, wherein the feeding end of the screw extruder is provided with a transmission device, the transmission device is connected to a mixing device, the mixing device is connected to the feeding device, the stretching machine includes a housing and a film body to be stretched in the housing, and the stretching machine further includes:

[0008] The stretching assembly is fixedly connected to the inner wall of the shell, and the film body is wound around the surface of the stretching assembly, including a heating stretching component and a cooling and shaping component. The heating stretching component stretches the film body in the heated state through the speed difference. After stretching, the film body remains in the stretched state and is cooled and transmitted to the cooling and shaping component to fix the stretched shape. The heating stretching component and the cooling and shaping component are rotatably arranged on the inner wall of the shell;

[0009] The transmission assembly is rotatably mounted on one side of the stretching assembly and drives the stretching assembly to operate, and includes a differential assembly and a uniform speed assembly. The differential assembly is rotatably mounted on one side of the heating stretching assembly and drives it to form a multi-stage transmission speed difference for the film body. The uniform speed assembly is rotatably mounted on one side of the cooling and shaping assembly and drives the cooling and shaping assembly to transmit the film body at a uniform speed.

[0010] A driver is installed on one side of the housing, an output shaft of the driver is fixedly connected to a driving gear, and the driving gear is meshed with one side of the transmission assembly;

[0011] The state limiting component is installed on one side of the heating and stretching component and the cooling and shaping component, elastically supporting the deflection of the heating and stretching component and the cooling and shaping component to control their maximum stretching speed, maintain the anti-reverse shutdown function, and unload the film stretching force;

[0012] The temperature control component is fixedly arranged on one side of the shell and is used to provide hot and cold air flows for the stretching assembly. It includes a fan and a heater fixed on the surface of the shell, and the air outlet of the fan is connected to the heater through the main air duct. The side walls of the heater and the main air duct are both provided with throttle valves for airflow control. Two connecting pipes connected to the stretching assembly are provided at the ports of the two throttle valves.

[0013] The fan of the temperature control component can provide wind power. The airflow flows out to one end of the shaping roller through the throttle valve and the connecting pipe on one side of the main air duct to provide cold airflow. The remaining airflow enters the heater and passes through the throttle valve on one side of the heater to make its fixed airflow pass through the connecting pipe and enter one end of the corresponding stretching roller, so that it provides hot airflow for heating the film body. The flow of cooling airflow and heating airflow can be controlled by the two throttle valves, and the heater can control the temperature of the heating airflow to achieve precise control.

[0014] As a further description of the above technical solution: the heating and stretching assembly includes a first bracket fixedly connected to the inner wall of the shell, the inner wall of the first bracket is rotatably provided with a heating roller group, and a plurality of first guide tubes are provided at both ends of the heating roller group.

[0015] As a further description of the above technical solution: the heating roller group includes a heating air cylinder rotatably connected to the inner wall of the first support frame, and both ends of the heating air cylinder are penetrated and fixed with a first retaining frame, and three stretching rollers are arranged on the opposite surfaces of the two first retaining frames to rotate together, and the two ends of several stretching rollers are connected in series through a first conduit, and one end of the corresponding stretching roller is connected to the corresponding side connecting pipe.

[0016] As a further description of the above technical solution: the cooling and shaping component includes a second retaining frame fixedly connected to the inner wall of the shell, the inner wall of the second retaining frame is rotatably connected to a cooling roller group, and a plurality of second ducts are provided on both sides of the cooling roller group.

[0017] As a further description of the above technical solution: the cooling roller group includes a cooling air tube rotatably arranged on the inner wall of the second support frame, and second retaining frames are fixed through both ends of the cooling air tube, and several shaping rollers are rotatably arranged on the opposite surfaces of the two second retaining frames, and the two ends of the several shaping rollers are connected in series through a second duct, and one end of the corresponding shaping roller is connected to another connecting pipe.

[0018] As a further description of the above technical solution: the differential assembly includes a first disc pulley rotatably connected to one end of the heating air cylinder, and the surface transmission of the first disc pulley is provided with a low-speed gear, a medium-speed pulley and a high-speed gear. The low-speed gear and the high-speed gear are meshed with the first disc pulley for transmission, and the medium-speed pulley is connected to the first disc pulley through a belt. The low-speed gear, the medium-speed pulley and the high-speed gear are respectively fixed on one end of their corresponding stretching rollers in a film contact transmission sequence, and the low-speed gear, the medium-speed pulley and the high-speed gear respectively drive the corresponding stretching rollers to rotate, and a speed difference is formed between adjacent stretching rollers.

[0019] As a further description of the above technical solution: the constant speed component includes a second disc wheel that is rotatably connected to one end of the cooling air cylinder, the surface of the second disc wheel is meshed with two constant speed gears, and the second disc wheel is connected to a constant speed pulley through a transmission belt.

[0020] As a further description of the above technical solution: the stretching roller and the shaping roller both include a heat-conducting tube, both ends of the heat-conducting tube are connected and fixed with end tubes, and a plurality of fins are fixed on the inner wall of the heat-conducting tube.

[0021] As a further description of the above technical solution: the first disc wheel and the second disc wheel are meshed for transmission, the first disc wheel is meshed for transmission with the driving gear, and the arcuate side walls of the first disc wheel and the second disc wheel are provided with belt grooves for matching belt transmission.

[0022] As a further description of the above technical solution: the state limiting component includes a pull rack fixedly connected to one end of the heating air duct, and the surface of the pull rack is fixedly connected to a height adjustment plate. The state limiting component also includes a pressure rack fixedly connected to one end of the cooling air duct, and the pressure rack is attached to the upper surface of the height adjustment plate. The upper surface of the pull rack is fixedly connected to a tension spring, and the top end of the tension spring is fixedly connected to an inclined rack, and the inclined rack is fixedly connected to the top of the first support frame.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] This solution uses a differential assembly to rotate several stretching rollers, and the several stretching rollers are connected to each other end to end through a first conduit. The heat provided by the temperature control assembly first enters the leftmost stretching roller, and then enters the rightmost stretching roller in sequence, and then enters the heating air duct. First, the film is stretched at the speed difference between the rightmost stretching roller and the middle stretching roller. During this process, the film is heated in sequence by the rightmost stretching roller and stretched once. Then the middle stretching roller heats it a second time and stretches the film a second time at the speed difference with the leftmost stretching roller. Finally, the leftmost stretching roller heats the film to the maximum temperature so that the stress after stretching can be eliminated. The hot air flow that gradually cools down from left to right is combined with the stretching that gradually increases from right to left. Under the guidance of the hot air flow ejected from the heating air duct, the film is transported and stretched between adjacent stretching rollers to maintain temperature uniformity. This method realizes step-by-step temperature control to ensure more precise temperature control and avoid large temperature fluctuations that affect the stretching quality. The temperature gradually increases during stretching, and no stretching effect is applied when the temperature is high, ensuring maximum stress elimination.

[0025] At the same time, after stretching, the film contacts the surfaces of the three shaping rollers of the cooling and shaping assembly from right to left in sequence, and the air flows from left to right in sequence on the shaping rollers, and the heated air flow is blown out evenly to the film through the cooling duct. This method cooperates with the second disc wheel meshed with the first disc wheel in the uniform speed assembly to rotate with two constant speed gears and a constant speed pulley at the same time, and then drives the three cooling rollers and the leftmost stretching roller to rotate at the same speed, so that the stretched film can be cooled step by step while maintaining its length, so that its stress is eliminated and it is completely shaped, thereby ensuring the quality of the film. The step-by-step temperature reduction control not only ensures more uniform cooling, but also avoids the occurrence of concentrated stress and adhesion after winding.

[0026] During use, the two first and second disc wheels rotating in opposite directions exert an opposite force on the heating roller group and the cooling roller group. This force is elastically supported by the state limiting component. If the rotation speed is too fast and exceeds the maximum stretching speed of the film body, the elastically supported state limiting component will be displaced, causing one of its constant speed gears to be stuck between the first disc wheel and the second disc wheel, thereby achieving shutdown, avoiding the stretching speed being exceeded and affecting the quality due to incorrect process parameter settings. At the same time, when shutting down, the state limiting component will clamp the high-speed gear between the first disc wheel and the second disc wheel to avoid reverse movement of the film body during the shutdown process, ensuring that the film body of each operating process during the shutdown process will not be displaced, ensuring the continuity of production during the restart process, and cooperating with the deflection of the heating and stretching component under the action of the state limiting component during shutdown, so that it can retract and unload the force on the film body during the heating and stretching process, avoiding film breakage caused by insufficient temperature and continuous stretching in the shutdown state, greatly ensuring the time period from the shutdown process to reproduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of the tape casting production line process of the present invention;

[0028] Figure 2 It is a three-dimensional structural diagram of the stretching machine of the stretching production line of the present invention;

[0029] Figure 3 This is a schematic diagram of the three-dimensional structure of the stretching machine housing after it is disassembled;

[0030] Figure 4 This is a schematic diagram of the coordination structure of the differential assembly and the heating roller assembly of the stretching machine of the present invention;

[0031] Figure 5 This is a schematic diagram of the coordination structure of the constant speed assembly and the cooling roller assembly of the stretching machine of the present invention;

[0032] Figure 6 It is a schematic diagram of the three-dimensional cross-sectional structure of the stretching machine of the present invention;

[0033] Figure 7 This is a three-dimensional structural diagram of the heating and stretching components and the cooling and shaping components of the stretching machine of the present invention;

[0034] Figure 8 It is a schematic structural diagram of the transmission assembly of the stretching machine of the present invention from the front view;

[0035] Figure 9 A schematic diagram of a front view of a state limiting assembly of a stretching machine according to the present invention;

[0036] Figure 10 Schematic diagram of a three-dimensional cross section of a stretching roller of a stretching machine of the present invention;

[0037] Figure 11 This is a schematic diagram of the rotation direction of the transmission assembly of the stretching machine of the present invention;

[0038] Figure 12 It is a schematic diagram of the force structure of the differential assembly and the uniform speed assembly of the stretching machine of the present invention.

[0039] Legend:

[0040] 1. Shell;

[0041] 2. Membranous body;

[0042] 3. Temperature control assembly; 31. Fan; 32. Main air duct; 33. Heater; 34. Throttle valve; 35. Connecting pipe;

[0043] 4. Stretch assembly;

[0044] 41. Heating and stretching assembly; 411. Heating roller assembly; 4111. First retaining frame; 4112. Heating air cylinder; 4113. Stretching roller; 41131. Heat-conducting cylinder; 41132. End tube; 41133. Fin; 412. First support frame;

[0045] 413, first catheter;

[0046] 42. Cooling and shaping assembly; 421. Cooling roller assembly; 4211. Second retaining frame; 4212. Cooling air duct; 4213. Shaping roller; 422. Second support frame; 423. Second guide tube;

[0047] 5. Transmission components;

[0048] 51, differential assembly; 511, first plate pulley; 512, low-speed gear; 513, medium-speed pulley; 514, high-speed gear;

[0049] 52. Constant speed assembly; 521. Second disc pulley; 522. Constant speed gear; 523. Constant speed pulley;

[0050] 6. State limiting assembly; 61. Inclined frame; 62. Tension spring; 63. Pull frame; 64. Press frame; 65. Height adjustment plate;

[0051] 7. Belt groove;

[0052] 8. Driver;

[0053] 9. Driving gear. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] like Figure 1-12 As shown, the present invention provides: a low-permeability film cast molding production line, including a cast molding production line composed of a screw extruder, a casting machine, a cooling device, a stretching machine, a cutting mechanism and a winding machine, the feeding end of the screw extruder is provided with a transmission device, the transmission device is connected to a mixing device, the mixing device is connected to the feeding device, the stretching machine includes a housing 1 and a film body 2 to be stretched in the housing 1, and the stretching machine also includes:

[0056] The stretching assembly 4 is fixedly connected to the inner wall of the shell 1. The film body 2 is wound around the surface of the stretching assembly 4 and includes a heating and stretching component 41 and a cooling and shaping component 42. The heating and stretching component 41 stretches the film body 2 in the heated state by a speed difference. After stretching, the film body 2 remains in the stretched state and is cooled and transferred to the cooling and shaping component 42 to fix the stretched shape. The heating and stretching component 41 and the cooling and shaping component 42 are rotatably arranged on the inner wall of the shell 1.

[0057] The heating and stretching assembly 41 controls the gradual heating and stretching of the film through speed differences, ensuring that the film is subjected to appropriate stretching forces and temperatures at different stages, ensuring a uniform stretching process and effectively improving the film's strength and ductility. By precisely controlling the film's heating, stretching, and cooling processes, film quality and production efficiency are improved, while also reducing the risk of film damage during downtime or malfunctions.

[0058] The transmission assembly 5 is rotatably mounted on one side of the stretching assembly 4 and drives the stretching assembly 4 to operate, and includes a differential assembly 51 and a uniform speed assembly 52. ​​The differential assembly 51 is rotatably mounted on one side of the heating and stretching assembly 41 and drives it to form a multi-stage transmission speed difference for the film body 2. The uniform speed assembly 52 is rotatably mounted on one side of the cooling and shaping assembly 42 and drives the cooling and shaping assembly 42 to transmit the film body 2 at a uniform speed.

[0059] The transmission assembly 5 controls the speed difference between the heating and stretching assembly 41 and the cooling and setting assembly 42 through the differential assembly 51 and the constant speed assembly 52, ensuring multi-stage transmission and uniform cooling of the film at different stages. The differential assembly 51 provides a speed difference during the heating phase, ensuring gradual stretching of the film, while the constant speed assembly 52 maintains stable film transmission during the cooling phase to avoid stress concentration.

[0060] A driver 8 is installed on one side of the housing 1, and an output shaft of the driver 8 is fixedly connected to a driving gear 9, which is meshed with one side of the transmission assembly 5;

[0061] The driver 8 is used for overall power input and drives the transmission assembly 5 through the driving gear 9.

[0062] The state limiting component 6 is installed on one side of the heating and stretching component 41 and the cooling and shaping component 42, elastically supporting the deflection of the heating and stretching component 41 and the cooling and shaping component 42, so as to control the maximum stretching speed and the maintenance of the shutdown anti-reverse and the stretching unloading of the membrane 2;

[0063] The temperature control component 3 is fixedly arranged on one side of the shell 1 and is used to provide hot and cold air flows for the stretching assembly 4. It includes a fan 31 and a heater 33 fixed on the surface of the shell 1, and the air outlet of the fan 31 is connected to the heater 33 through the main air duct 32. The side walls of the heater 33 and the main air duct 32 are both provided with throttle valves 34 for air flow control, and two connecting pipes 35 connected to the stretching assembly 4 are provided at the ports of the two throttle valves 34.

[0064] The temperature control component 3 can provide hot air flow and normal temperature air flow, and controls the heating and cooling efficiency of the membrane body 2 by controlling the air flow rate and temperature.

[0065] The heating and stretching assembly 41 includes a first support frame 412 fixedly connected to the inner wall of the shell 1 , a heating roller group 411 is rotatably provided on the inner wall of the first support frame 412 , and a plurality of first guide tubes 413 are provided at both ends of the heating roller group 411 .

[0066] Specifically, such as Figure 4 As shown, the heating roller group 411 includes a heating air cylinder 4112 rotatably connected to the inner wall of the first support frame 412, and the first retaining frame 4111 is fixed through both ends of the heating air cylinder 4112. Three stretching rollers 4113 are provided on the opposite surfaces of the two first retaining frames 4111 to rotate together, and the two ends of several stretching rollers 4113 are connected in series through the first conduit 413, and one end of the corresponding stretching roller 4113 is connected to the corresponding side connecting pipe 35.

[0067] The heating air cylinder 4112 can gather the heated air flow in the heating roller and spray it out evenly. Combined with the flow control of the temperature control component 3, the hot air flow can evenly heat the surface of the film body 2, so that the environment maintains a certain temperature during the transmission process, avoiding the ambient temperature affecting the temperature of the surface of the film body 2 and causing a large difference, reducing the impact of ambient temperature factors, and actively creating a suitable stretching environment.

[0068] Specifically, such as Figure 7 As shown, the cooling and shaping component 42 includes a second retaining frame 4211 fixedly connected to the inner wall of the shell 1, and the inner wall of the second retaining frame 4211 is rotatably connected to a cooling roller group 421, and a plurality of second ducts 423 are provided on both sides of the cooling roller group 421.

[0069] By providing the second conduit 423 , the second conduit 423 is rotatably connected to one end of the corresponding two cooling roller groups 421 , and the cooling roller groups 421 are kept connected in series, so that the airflow can flow in sequence and carry heat.

[0070] Specifically, such as Figure 5As shown, the cooling roller group 421 includes a cooling air tube 4212 rotatably arranged on the inner wall of the second support frame 422, and a second retaining frame 4211 is fixed through both ends of the cooling air tube 4212. A plurality of shaping rollers 4213 are rotatably arranged on the opposite surfaces of the two second retaining frames 4211, and the two ends of the plurality of shaping rollers 4213 are connected in series through a second duct 423, and one end of the corresponding shaping roller 4213 is connected to another connecting pipe 35.

[0071] By setting up the cooling air duct 4212, the cooling air duct 4212 can converge the airflow that completes the heat exchange in the shaping roller 4213, and keep the airflow evenly dispersed, so that the airflow velocity on the surface of the membrane body 2 is maintained, so that while it is cooling the surface of the shaping roller 4213, there is also airflow with a certain temperature flowing on the surface. While the temperature is lowered step by step, the surface is also cooled synchronously and evenly, thereby improving the speed and efficiency of cooling.

[0072] Specifically, such as Figure 4 As shown, the differential assembly 51 includes a first pulley 511 rotatably connected to one end of the heating cylinder 4112, and the surface transmission of the first pulley 511 is provided with a low-speed gear 512, a medium-speed pulley 513 and a high-speed gear 514. The low-speed gear 512 and the high-speed gear 514 are meshed with the first pulley 511 for transmission, and the medium-speed pulley 513 is connected to the first pulley 511 for transmission through a belt. The low-speed gear 512, the medium-speed pulley 513 and the high-speed gear 514 are respectively fixed on one end of their corresponding stretching rollers 4113 in the contact transmission sequence of the film body 2, and the low-speed gear 512, the medium-speed pulley 513 and the high-speed gear 514 respectively drive the corresponding stretching rollers 4113 to rotate, and a speed difference is formed between adjacent stretching rollers 4113.

[0073] The differential assembly 51 can change the elongation of the membrane 2 under the action of the rotational speed difference.

[0074] Specifically, such as Figure 5 As shown, the constant speed component 52 includes a second disc pulley 521 rotatably connected to one end of the cooling air cylinder 4212, and the surface of the second disc pulley 521 is meshed with two constant speed gears 522, and the second disc pulley 521 is connected to a constant speed pulley 523 through a transmission belt.

[0075] The two constant speed gears 522 and the constant speed pulley 523 are consistent with the wheel diameter of the high-speed gear 514, so that they can maintain a synchronous rotation speed. After the heating and stretching is completed, the film body 2 can maintain the speed for transmission without speed difference, ensuring that the elongation is in a stable state for cooling.

[0076] Specifically, such as Figure 10As shown, the stretching roller 4113 and the shaping roller 4213 both include a heat-conducting tube 41131 , both ends of the heat-conducting tube 41131 are connected and fixed with end tubes 41132 , and a plurality of fins 41133 are fixedly attached to the inner wall of the heat-conducting tube 41131 .

[0077] The stretching roller 4113 and the shaping roller 4213 have the same structure, including a heat-conducting tube 41131 that contacts the film body 2 and conducts heat. The end tubes 41132 at both ends can achieve a rotational connection with the first conduit 413 or the second conduit 423. The fins 41133 on the inner wall of the heat-conducting tube 41131 can achieve faster heat exchange.

[0078] Specifically, such as Figure 4 As shown, the first disc pulley 511 and the second disc pulley 521 are engaged in transmission, the first disc pulley 511 is engaged in transmission with the driving gear 9, and the arcuate side walls of the first disc pulley 511 and the second disc pulley 521 are provided with belt grooves 7 for cooperating with belt transmission.

[0079] By setting up the belt groove 7, the belt groove 7 is opened on the side wall of the first wheel and the second wheel, which can be coordinated with the belt. The first wheel 511 and the second wheel 521 are engaged with each other, and can maintain the transmission between each other when in use. In addition, this method can realize that during the operation of the heating and stretching component 41, the cooling and shaping component 42 can operate synchronously with it to achieve synchronous drive.

[0080] Specifically, such as Figure 9 As shown, the state limiting component 6 includes a pull rack 63 fixedly connected to one end of the heating air duct 4112, and the surface of the pull rack 63 is fixedly connected to a height adjustment plate 65. The state limiting component 6 also includes a pressure rack 64 fixedly connected to one end of the cooling air duct 4212, and the pressure rack 64 is attached to the upper surface of the height adjustment plate 65. The upper surface of the pull rack 63 is fixedly connected to a tension spring 62, and the top end of the tension spring 62 is fixedly connected to an inclined rack 61, and the inclined rack 61 is fixedly connected to the top of the first support frame 412.

[0081] By setting up the height adjustment plate 65, when in use, by replacing different height adjustment plates 65, the distance between the pressure frame 64 and the pulling frame 63 can be adjusted, and the pressure frame 64 presses the pulling frame 63 at different distances. If the length of the height adjustment plate 65 becomes shorter, the extension of the tension spring 62 is shorter, and its constant speed gear 522 will contact the first disc wheel 511. If the length of the height adjustment plate 65 increases, the extension of the tension spring 62 needs to be greater, and the corresponding constant speed gear 522 needs to move a longer trajectory before it can engage with the first disc wheel 511. The range of its maximum stretching speed can be adjusted according to the shape of different membrane bodies 2. When in use, the constant speed gear 522 can be shut down after engaging the first disc wheel 511. During the shutdown process, the coupling of the driver 8 will break and enter the synchronous power-off protection state. When the sensor fails, its speed will be out of control and enter the protection state to avoid disconnection of the membrane body 2.

[0082] The first wheel of the differential assembly 51 rotates under the meshing of the driver 8 and the driving gear 9, and the first wheel meshes with the low-speed gear 512 and the high-speed gear 514 on the surface to rotate in the opposite direction, and the first wheel rotates synchronously with the medium-speed pulley 513 through the belt. At this time, the low-speed gear 512, the high-speed gear 514 and the medium-speed pulley 513 simultaneously rotate with the three stretching rollers 4113. The rotating stretching rollers 4113 are connected to each other from left to right through the first duct 413. The heat provided by the temperature control component 3 first enters the leftmost stretching roller 4113, and then enters the rightmost stretching roller 4113 and then enters the heating air cylinder 4112, so that the film body 2 is successively attached to the surface of the stretching roller 4113 from right to left, and the contacting stretching rollers The temperature of the stretching roller 4113 is gradually increased. First, the film body 2 is stretched under the rotation speed difference between the rightmost stretching roller 4113 and the middle stretching roller 4113. During this process, the film body 2 is heated in sequence by the rightmost stretching roller 4113 and stretched once. Then the middle stretching roller 4113 heats it for the second time and stretches the film body 2 for the second time under the rotation speed difference with the leftmost stretching roller 4113. Finally, the leftmost stretching roller 4113 heats the film body 2 to the maximum temperature so that the stress after stretching can be eliminated. The hot air flow with gradually decreasing temperature from left to right is matched with the stretching with gradually increasing temperature from right to left. Under the guidance of the hot air flow directionally ejected from the heating air cylinder 4112, the film body 2 is transported and stretched by the adjacent stretching rollers 4113 and kept warm to maintain temperature uniformity.

[0083] The film body 2 is uniformly blown out through the cooling duct 4212 to the film body 2. The second disc 521 meshed with the first disc 511 in the uniform speed component 52 drives the two constant speed gears 522 to rotate in opposite directions, and drives the constant speed pulley 523 to rotate synchronously, thereby driving the three cooling rollers and the leftmost stretching roller 4113 to rotate at the same speed, so that the stretched film body 2 can be cooled step by step in the state of maintaining the length, so that the stress is eliminated and the film body 2 is completely shaped. The cooling and shaping process is in a gradually decreasing process, which ensures the quality of the film body 2. The temperature drop is controlled step by step, which not only ensures that the cooling is more uniform, but also avoids the situation that the concentrated stress after winding causes adhesion.

[0084] When in use, the two first and second disc wheels 511, 521 rotating in opposite directions exert an opposite force on the heating roller group 411 and the cooling roller group 421. When started, the driving gear 9 rotates with the first disc wheel 511, and the heating air cylinder 4112 and the cooling air cylinder 4212 of the heating roller group 411 and the cooling roller group 421 are respectively slightly rotated on the inner walls of the first retaining frame 4111 and the second retaining frame 4211 by the force, wherein the pulling frame 63 of the state limiting component 6 is fixed at one end of the heating air cylinder 4112, and the pressing frame 64 is fixed at one end of the cooling air cylinder 4212, wherein the force of the opposite movement causes the pressing frame 64 to press the pulling frame 63 through the height adjustment plate 65, and the pulling frame 63 pulls the tension spring 62 to stretch. When the speed is long, the tension spring 62 is extended, and the high-speed gear 514 engages with the first disc wheel 511 and moves at the same time, so that the high-speed gear 514 disengages from the second disc wheel 521, making it rotate. When the speed increases, the extension of the tension spring 62 becomes larger, and the constant speed gear 522 on the right side engages with the second disc wheel 521 and gradually approaches the first disc wheel 511. Based on the limited heating and cooling efficiency of the heating roller and the cooling roller, if the speed of the film body 2 is too fast, the stretching quality cannot be guaranteed, and it is very easy to cause uneven stretching due to insufficient heating or stress concentration due to insufficient cooling and winding. When the stretching speed range is exceeded, the constant speed gear 522 on the right side engages with the surface of the first disc wheel 511, causing it to stop and pass the self-inspection of the staff;

[0085] When the components are damaged during long-term operation, the machine needs to be shut down for maintenance. During the shutdown process, the heating roller group 411 loses the directional force of the first wheel rotation process and the high-speed gear 514, the low-speed gear 512 and the medium-speed pulley 513. Figure 12As shown, after the force is lost, the tension spring 62 pulls the pulling frame 63 and causes the heating cylinder 4112 to rotate. At the same time, the first retaining frame 4111 on both sides of the heating cylinder 4112 engages with the second disc wheel 521 with the high-speed gear 514, thereby achieving overall locking and preventing the membrane body 2 from moving in the opposite direction.

[0086] This force is elastically supported by the state limiting component 6. If the rotation speed is too fast and exceeds the maximum stretching speed of the membrane body 2, the elastically supported state limiting component 6 will be displaced, causing one of its constant speed gears 522 to be stuck between the first disc wheel 511 and the second disc wheel 521, thereby achieving shutdown, avoiding the error in setting process parameters that causes the stretching speed to be exceeded and affecting the quality. At the same time, when shutting down, the state limiting component 6 will clamp the high-speed gear 514 between the first disc wheel 511 and the second disc wheel 521 to avoid reverse movement of the membrane body 2 during the shutdown process, ensuring that the membrane body 2 in each operating process during the shutdown process will not be displaced, ensuring the continuity of production during the restart process, and cooperating with the deflection of the heating stretching component 41 under the action of the state limiting component 6 during the shutdown, so that it can retract and unload the force on the membrane body 2 during the heating stretching process, avoiding film breakage caused by insufficient temperature and continuous stretching in the shutdown state, greatly ensuring the time period from the shutdown process to reproduction.

[0087] This solution proposes an effective solution to the problems of inaccurate temperature control, uneven stretching, stress concentration, and film breakage during shutdown in traditional low-permeability film cast molding production lines. Through the cooperation of the differential component 51 and the uniform speed component 52, accurate temperature regulation and speed difference control can be achieved during the film stretching process, ensuring the uniformity of the film's step-by-step stretching and avoiding the problem of local over-stretching or under-stretching. At the same time, the cooling and shaping component 42 makes the film cooling more uniform by gradually lowering the temperature, reducing the risk of stress concentration during the cooling process, and effectively improving the thickness consistency and physical properties of the film. In addition, the state limiting component 6 can automatically prevent the film from being pulled in the opposite direction when the machine is shut down, and through the unloading mechanism of the heating and stretching component 41, it effectively relieves the tensile stress and prevents the problem of film breakage during the shutdown process. This solution not only reduces the waste of raw materials, but also greatly shortens the recovery time after shutdown, improves production efficiency and film quality, and ensures the stability and continuity of the production line.

[0088] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A low-permeability film tape casting production line, the tape casting production line comprising a stretching machine, the stretching machine comprising a shell (1) and a film body (2) stretched in the shell (1), characterized in that: The stretching machine also includes: A stretching assembly (4) is fixedly connected to the inner wall of the shell (1); the film body (2) is wound around the surface of the stretching assembly (4), and comprises a heating stretching component (41) and a cooling shaping component (42); the heating stretching component (41) stretches the film body (2) in a heated state by a rotation speed difference; after stretching, the film body (2) maintains the stretched state and is cooled and transmitted by the cooling shaping component (42) to fix the stretched shape; the heating stretching component (41) and the cooling shaping component (42) are rotatably arranged on the inner wall of the shell (1); The transmission assembly (5) is rotatably mounted on one side of the stretching assembly (4) and drives the stretching assembly (4) to operate, and comprises a differential assembly (51) and a uniform speed assembly (52); the differential assembly (51) is rotatably mounted on one side of the heating stretching assembly (41) and drives it to form a multi-stage transmission speed difference for the film body (2); the uniform speed assembly (52) is rotatably mounted on one side of the cooling and shaping assembly (42) and drives the cooling and shaping assembly (42) to uniformly transmit the film body (2); A driver (8) is installed on one side of the housing (1); an output shaft of the driver (8) is fixedly connected to a driving gear (9); and the driving gear (9) is meshed with one side of the transmission assembly (5); A state limiting component (6) is installed on one side of the heating and stretching component (41) and the cooling and shaping component (42), and elastically supports the deflection of the heating and stretching component (41) and the cooling and shaping component (42) to control the maximum stretching speed and the maintenance of the shutdown anti-reverse and the stretching unloading of the membrane body (2); A temperature control component (3) is fixedly arranged on one side of the housing (1) and is used to provide hot and cold airflows for the stretching assembly (4), comprising a fan (31) and a heater (33) fixed on the surface of the housing (1), wherein the air outlet of the fan (31) is connected to the heater (33) via a main air duct (32), and the side walls of the heater (33) and the main air duct (32) are both provided with throttle valves (34) for airflow control, and two connecting pipes (35) connected to the stretching assembly (4) are provided at the ports of the two throttle valves (34); The differential assembly (51) comprises a first disk wheel (511) rotatably connected to one end of the heating air cylinder (4112); a surface transmission of the first disk wheel (511) is provided with a low-speed gear (512), a medium-speed pulley (513) and a high-speed gear (514); the low-speed gear (512) and the high-speed gear (514) are meshed with the first disk wheel (511) for transmission; the medium-speed pulley (513) is transmission-connected to the first disk wheel (511) via a belt; the low-speed gear (512), the medium-speed pulley (513) and the high-speed gear (514) are respectively fixed to one end of the corresponding stretching roller (4113) in the order in which the film body (2) contacts the stretching roller (4113) in sequence; the low-speed gear (512), the medium-speed pulley (513) and the high-speed gear (514) respectively drive the corresponding stretching roller (4113) to rotate, and a speed difference is formed between adjacent stretching rollers (4113); The state limiting component (6) includes a pull frame (63) fixedly connected to one end of the heating air duct (4112), and a height adjustment plate (65) is fixedly connected to the surface of the pull frame (63). The state limiting component (6) also includes a pressure frame (64) fixedly connected to one end of the cooling air duct (4212), and the pressure frame (64) is attached to the upper surface of the height adjustment plate (65). The upper surface of the pull frame (63) is fixedly connected to a tension spring (62), and the top end of the tension spring (62) is fixedly connected to an inclined frame (61), and the inclined frame (61) is fixedly connected to the top of the first support frame (412).

2. A low-permeability film casting production line according to claim 1, characterized in that: The heating and stretching assembly (41) comprises a first support frame (412) fixedly connected to the inner wall of the shell (1), a heating roller group (411) being rotatably arranged on the inner wall of the first support frame (412), and a plurality of first guide tubes (413) being arranged at both ends of the heating roller group (411).

3. A low-permeability film casting production line according to claim 2, characterized in that: The heating roller group (411) comprises a heating air cylinder (4112) rotatably connected to the inner wall of the first support frame (412), both ends of the heating air cylinder (4112) penetrate and are fixed with a first retaining frame (4111), and three stretching rollers (4113) are arranged on opposite surfaces of the two first retaining frames (4111) for co-rotation, and both ends of the plurality of stretching rollers (4113) are connected in series via a first guide tube (413), and one end of a corresponding stretching roller (4113) is connected to a corresponding side connecting pipe (35).

4. A low-permeability film tape casting production line according to claim 3, characterized in that: The cooling and shaping component (42) comprises a second retaining frame (4211) fixedly connected to the inner wall of the shell (1), the inner wall of the second retaining frame (4211) being rotatably connected to a cooling roller group (421), and a plurality of second guide tubes (423) are provided on both sides of the cooling roller group (421).

5. A low-permeability film casting production line according to claim 4, characterized in that: The cooling roller group (421) comprises a cooling air tube (4212) rotatably arranged on the inner wall of the second support frame (422), and the second retaining frames (4211) are both penetrated and fixed at both ends of the cooling air tube (4212), and a plurality of shaping rollers (4213) are rotatably arranged on opposite surfaces of the two second retaining frames (4211), and the two ends of the plurality of shaping rollers (4213) are connected in series through a second guide tube (423), and one end of a corresponding shaping roller (4213) is connected to another connecting pipe (35).

6. The low-permeability film tape casting production line according to claim 1, characterized in that: The constant speed component (52) comprises a second disk wheel (521) rotatably connected to one end of the cooling air cylinder (4212), the surface of the second disk wheel (521) being meshed with two constant speed gears (522), and the second disk wheel (521) is connected to a constant speed pulley (523) via a transmission belt.

7. A low-permeability film casting production line according to claim 5, characterized in that: The stretching roller (4113) and the shaping roller (4213) both comprise a heat-conducting tube (41131), both ends of the heat-conducting tube (41131) are connected and fixed with end tubes (41132), and a plurality of fins (41133) are fitted and fixed to the inner wall of the heat-conducting tube (41131).

8. The low-permeability film tape casting production line according to claim 6, characterized in that: The first disk wheel (511) and the second disk wheel (521) are meshed for transmission, the first disk wheel (511) is meshed for transmission with the driving gear (9), and the arc-shaped side walls of the first disk wheel (511) and the second disk wheel (521) are provided with belt grooves (7) for matching belt transmission.

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