Automatic exhaust structure made of POF film

Abstract

The invention relates to the technical field of POF film preparation, and particularly discloses an automatic exhaust structure for POF film manufacturing, which comprises an extrusion mechanism and an exhaust mechanism, the extrusion mechanism comprises a mounting seat, an extrusion assembly, an adjusting assembly and a linear driving part, the linear driving piece drives the mounting base and the extrusion assembly to slide in the length direction of the film and extrudes out gas in the film bubbles; the exhaust mechanism comprises an exhaust channel and a pressure regulating valve, the exhaust channel and the pressure regulating valve are both arranged on the extrusion die head, the exhaust channel is embedded in the extrusion die head, one end of the exhaust channel penetrates out of the extrusion side of the extrusion die head, and the other end of the exhaust channel is communicated with the pressure regulating valve. And the constant pressure is kept in the film pipe on the extrusion side of the extrusion die head. According to the POF film exhaust device, gas in film bubbles of a POF film at the inlet of the irradiation chamber can be exhausted, and the exhaust process can be completed without shutdown, so that exhaust is more convenient, and the exhaust cost can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of POF film preparation, and in particular to an automatic exhaust structure made of a POF film. Background Art

[0002] POF film, short for multi-layer co-extruded polyolefin heat shrink film, is a type of heat shrink film typically manufactured through a process involving plasticization through an extruder, die forming, and bubble inflation. Due to its non-toxic and environmentally friendly properties, high transparency, high shrinkage, and excellent heat-sealing properties, it is widely used in packaging for food, medicine, daily necessities, and sanitary products.

[0003] When preparing POF film, a section of circular tubular film tube is first extruded outward through the extrusion die head of the extruder, and then the film tube is transported to the traction roller after cooling; there are two traction rollers and they are located on both sides of the film tube. The circular tubular film tube is squeezed into a flat shape after passing through the traction rollers; then the flat POF film is pulled and transported to the irradiation chamber for processing through the two traction rollers at the entrance of the irradiation chamber. Irradiation can improve the performance of the POF film.

[0004] The irradiation chamber is a high-temperature and high-pressure environment. In this high-temperature and high-pressure environment, gas is easily generated inside the POF film. The gas will flow into a flat section of POF film before entering the irradiation chamber, causing this section of POF film to gradually bulge and form a bubble. Since the gas in the bubble cannot be discharged, as the gas accumulates, the bubble becomes larger and larger. Excessively large bubbles will affect the process of the POF film passing through the traction roller into the irradiation chamber, which is likely to affect the subsequent production process. Summary of the Invention

[0005] In order to facilitate the discharge of gas in the film bubbles of the POF film at the entrance of the irradiation chamber, the present application provides an automatic exhaust structure made of the POF film.

[0006] The present application provides a POF film-made automatic exhaust structure using the following technical solutions: A POF film is made into an automatic exhaust structure, which is arranged on a forming device. The forming device includes an extrusion die, a traction roller, a guide roller and an irradiation chamber. The traction roller is arranged on the extrusion side of the extrusion die, and the guide roller is arranged between the traction roller and the irradiation chamber, so that the film extruded by the extrusion die can be sequentially conveyed to the irradiation chamber through the traction roller and the guide roller. The structure includes: a squeezing mechanism, wherein the squeezing mechanism is arranged on the outside of the irradiation chamber entrance, the squeezing mechanism comprises a mounting seat, a squeezing assembly, an adjusting assembly and a linear driving member, the squeezing assembly and the adjusting assembly are both arranged on the mounting seat, the squeezing assembly is provided with two groups, the two squeezing assemblies are respectively used to press against the two sides of the film between the guide roller and the irradiation chamber, the adjusting assembly is used to drive the two squeezing assemblies to move in opposite directions so that the two squeezing assemblies are respectively pressed against the two sides of the film or are arranged at intervals on the two sides of the film, the linear driving member is arranged on one side of the irradiation chamber, the mounting seat is fixedly arranged at the movable end of the linear driving member, so that the linear driving member drives the mounting seat and the squeezing assembly to slide along the length direction of the film and squeeze out the gas in the film bubble; An exhaust mechanism, the exhaust mechanism comprising an exhaust channel and a pressure regulating valve, both of which are provided on the extrusion die head, the exhaust channel being provided inside the extrusion die head, one end of the exhaust channel passing through the extrusion side of the extrusion die head, and the other end of the exhaust channel being connected to the pressure regulating valve, so that a constant pressure is maintained in the film tube on the extrusion side of the extrusion die head; The traction roller and the guide roller are both provided with exhaust grooves, which are annular grooves. When the extrusion mechanism is in operation, one side of the film can be pressed against the bottom wall of the exhaust groove, thereby providing space for the flow of gas in the film. The gas in the film bubble outside the irradiation chamber inlet can flow into the film tube at the end of the extrusion die through the exhaust groove. When the pressure in the film tube increases, the exhaust valve will open to discharge excess gas.

[0007] By adopting the above technical solution, during exhaust, the two extrusion components are respectively pressed against the upper and lower sides of the film bubble at the entrance of the irradiation chamber, and the linear drive component drives the two extrusion components to slide toward the side close to the guide roller, so that the gas in the film bubble can be squeezed out. The setting of the exhaust groove provides space for the expansion and bulging of the POF film, so that the gas squeezed out of the film bubble can flow into the film tube below the extrusion die through the exhaust groove. As the gas entering the film tube gradually increases, the air pressure in the film tube increases, which can open the pressure regulating valve to discharge the excess gas in the film tube, thereby completing the exhaust process; thus, the machine can be operated without stopping. In this case, the gas in the membrane tube can be discharged, so that the POF membrane can smoothly enter the irradiation chamber, which is conducive to the smooth progress of the POF membrane production process and can reduce the cost of exhaust; the adjusting component can change the position of the two extrusion components. When extruding and exhausting, the two extrusion components are respectively pressed against the upper and lower sides of the membrane bubble. After the exhaust is completed, the two extrusion components are respectively arranged at intervals on the upper and lower sides of the membrane bubble. Therefore, the gas generated in the membrane in the irradiation chamber can smoothly enter the membrane bubble, and the gas generated in the membrane in the irradiation chamber will not accumulate inside the irradiation chamber, which is conducive to the smooth exhaust of the gas later.

[0008] Optionally, two exhaust grooves are provided on the traction roller and are respectively located at both ends of the traction roller, and two exhaust grooves are provided on the guide roller and are respectively located at both ends of the guide roller.

[0009] By adopting the above technical solution, both sides of the POF film can bulge at the exhaust groove, which helps to increase the exhaust volume and can better discharge the gas in the film bubble.

[0010] Optionally, the extrusion assembly includes a mounting block and an extrusion roller, the mounting block is slidably arranged on the mounting seat, and the extrusion roller is rotatably connected to the mounting block, and the sides of the two extrusion rollers close to each other can respectively press against both sides of the film.

[0011] By adopting the above technical solution, the squeezing roller is pressed against the film bubble, and the squeezing roller can rotate while sliding, which can protect the film bubble and prevent the squeezing roller from scratching the film bubble during the sliding process, thereby ensuring the molding quality of the POF film.

[0012] Optionally, each of the squeezing rollers is coaxially fixedly connected with a gear, and when the two squeezing rollers are respectively pressed against two sides of the film, the two gears are meshed.

[0013] By adopting the above technical solution, when one of the squeezing rollers rotates, it can drive the other squeezing roller to rotate, so that the two squeezing rollers can rotate synchronously, thereby avoiding the squeezing rollers rotating asynchronously and causing the POF film to wrinkle or even break.

[0014] Optionally, a flexible pad is provided on the outer side of the squeezing roller.

[0015] By adopting the above technical solution, the provision of the flexible pad can enable better contact between the extrusion roller and the film bubble, which helps to ensure the exhaust effect and can also protect the film bubble to avoid scratching the film bubble.

[0016] Optionally, the adjustment assembly includes a spring, a protrusion, a first stop, a second stop and a fixing component, the spring is connected between the mounting block and the mounting seat, so that the two mounting blocks on the same mounting seat have a tendency to slide toward each other, the protrusion is fixedly connected to the mounting block, both sides of the protrusion are provided with inclined surfaces, the first stop and the second stop are respectively provided at two ends of a moving path of the mounting seat, the first stop and the second stop are both provided with inclined surfaces that match the inclined surfaces on the protrusion, and the fixing component is provided between the mounting block and the mounting seat, for fixing the mounting block to the mounting seat; When the protrusion abuts against the first stop block, the two protrusions slide toward the side away from each other, and the mounting block is fixed to the mounting seat by the fixing component, and the squeezing roller and the film are separated. When the protrusion abuts against the second stop block, the two protrusions slide toward the side close to each other, and the two squeezing rollers are respectively pressed against the two sides of the film.

[0017] By adopting the above technical solution, under normal circumstances, the spring makes the two squeezing rollers press against the upper and lower sides of the film bubble. As the squeezing rollers slide, the cooperation between the first stop block and the protrusion and the cooperation between the second stop block and the protrusion can make the two squeezing rollers slide in opposite directions, thereby adjusting the positions of the squeezing rollers. Therefore, the setting of the adjustment component makes it possible to simultaneously complete the adjustment of the positions of the squeezing rollers when the linear drive member drives the squeezing rollers to slide to the upper and lower limit positions. The position adjustment of the squeezing rollers does not require the setting of other power sources, thereby reducing energy consumption.

[0018] Optionally, the fixing component includes a first magnet block and a second magnet block, the first magnet block is fixedly connected to the mounting block, the second magnet block is fixedly connected to the mounting seat, and the magnetic poles of the first magnet block and the second magnet block on the side close to each other are in opposite directions.

[0019] By adopting the above technical solution, with the cooperation of the protrusion and the first stop block, the two squeezing rollers are moved away from each other, and when the first magnet block and the second magnet block are attracted, the mounting block can be fixed on the mounting seat, thereby fixing the squeezing roller on the side away from the POF film; therefore, the squeezing roller set separately from the POF film will not affect the gas flow in the film bubble, so that under the high temperature and high pressure environment, the gas generated in the POF film in the irradiation chamber can smoothly flow into the POF film outside the irradiation chamber entrance, thereby forming a film bubble, which is convenient for the subsequent discharge of the gas in the film bubble through the sliding squeezing roller.

[0020] Optionally, a partition mechanism is provided on the traction roller, and the partition mechanism includes an annular airbag and an air pump. The annular airbag is fixedly connected to the exhaust groove. When the annular airbag is filled with air, the outer side of the annular airbag is flush with the outer surface of the traction roller. The air pump is provided on one side of the traction roller and is connected to the annular airbag. When the extrusion mechanism is in a stationary state, the annular airbag is filled with air and pressed against one side of the membrane.

[0021] By adopting the above technical solution, when the extrusion mechanism is in a non-working state, the extrusion roller and the POF film are in a separated state, and the annular airbag is in a bulging state. The outer surface of the annular airbag is flush with the traction roller, so that the middle part of the POF film at the traction roller is pressed against the traction roller, and the edge of the POF film at the traction roller is pressed against the outer surface of the annular airbag, so that the POF film is squeezed into a flat shape at the traction roller, and the end of the film tube close to the traction roller is blocked, so that the exhaust groove cannot temporarily play the role of exhaust, thereby further reducing the possibility of gas in the film tube flowing into the film bubble behind, so that the gas in the film bubble outside the irradiation chamber inlet is all gas flowing out of the film in the irradiation chamber, which can reduce the number of exhaust times and is more convenient.

[0022] Optionally, an air supply component is provided between the annular airbag and the air pump, and the air supply component includes a connecting ring, an air supply disc and an air supply pipe. The connecting ring is fixedly connected to the inner wall of the annular airbag, the connecting ring is communicated with the annular airbag, the air supply disc is embedded in the traction roller, and a cavity for accommodating air is provided in the air supply disc. The air supply disc and the connecting ring are rotatably connected and communicated with each other. The air supply pipe is fixedly connected to the air supply disc and is used to communicate with the air pump.

[0023] By adopting the above technical solution, the annular airbag and the air pump can be smoothly connected without affecting the rotation of the traction roller, thereby ensuring the smooth inflation and deflating process of the air pump.

[0024] Optionally, a sensor and an alarm are provided on the outside of the irradiation chamber, and the sensor and the alarm are electrically connected.

[0025] By adopting the above technical solution, the sensor can detect the size of the membrane bubble. When the membrane bubble is too large, it indicates that there is more gas in the membrane bubble. At this time, the alarm can sound an alarm to prompt the operator to exhaust in time.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The setting of the extrusion mechanism enables the gas in the film bubble to be discharged without stopping the machine. Since the POF film does not need to be pierced for exhaust, it helps to ensure the integrity of the POF film. There is no need to re-pull the bubble and start the machine later, which helps to reduce the exhaust cost and ensure the smooth progress of the subsequent molding process.

[0027] 2. When the linear drive component drives the squeezing roller to slide to the upper and lower limit positions, the adjustment component can change the position of the squeezing roller. The switching of the squeezing roller position does not require the setting of an additional power source, thus being more energy-efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a working principle diagram of Example 1 of the present application; Figure 2 is a front view of Example 1 of the present application; Figure 3 This is a schematic diagram of the overall structure of Example 1 of the present application; Figure 4 yes Figure 3 A magnified schematic diagram of point A in the middle; Figure 5 is a cross-sectional view of Example 1 of the present application for illustrating the exhaust mechanism; Figure 6 is a cross-sectional view of Example 1 of the present application along the axis of the guide roller; Figure 7 yes Figure 6 A magnified schematic diagram of point B in the middle; Figure 8 This is a cross-sectional view of Example 2 of the present application for illustrating a partition mechanism; Figure 9 yes Figure 8 Enlarged schematic diagram of point C in the middle.

[0029] Reference numerals: 1, forming device; 11, extrusion die; 12, pulling roller; 13, guide roller; 14, irradiation chamber; 141, feed roller; 15, cooling ring; 2, extrusion mechanism; 21, mounting seat; 211, slide; 22, extrusion assembly; 221, mounting block; 222, extrusion roller; 2221, gear; 23, adjustment assembly; 231, spring; 232, bump; 233, first stopper; 234 , second block; 235, fixing component; 2351, first magnet block; 2352, second magnet block; 24, linear drive component; 3, exhaust mechanism; 31, exhaust channel; 32, pressure regulating valve; 4, exhaust groove; 5, partition mechanism; 51, annular airbag; 52, air pump; 6, air supply component; 61, connecting ring; 62, air supply disk; 63, air supply pipe; 7, membrane bubble; 8, bracket; 9, branch pipe; 10, membrane tube. DETAILED DESCRIPTION

[0030] The following combination Figures 1-9 This application is described in further detail.

[0031] Example 1 The embodiment of the present application discloses a POF film made into an automatic exhaust structure. Figure 1 The POF film is made into an automatic exhaust structure and is set on a molding device 1. The molding device 1 includes an extrusion die 11, a cooling ring 15, a pulling roller 12, a guide roller 13 and an irradiation chamber 14. The extrusion die 11 is connected to the extruder. The bottom end of the extrusion die 11 is the extrusion side and is provided with an annular extrusion groove, so that the bottom end of the extrusion die 11 can extrude a soft tubular film tube 10 downward. The cooling ring 15 is located below the extrusion die 11. Cooling water circulates in the cooling ring 15. The outer wall of the film tube 10 extruded from the extrusion die 11 is against the inner wall of the cooling ring 15, so that the extruded film tube 10 can be cooled, thereby increasing the hardness and stability of the film tube 10. The traction roller 12 is arranged below the cooling ring 15. There are two traction rollers 12 and they are arranged in parallel. The traction rollers 12 are driven by a motor, so the motor can drive the two traction rollers 12 to rotate in opposite directions. The cooled film tube 10 can pass between the two traction rollers 12. The traction rollers 12 can press the round tube-shaped film tube 10 into a flat film, and then transport the flat film backward.

[0032] Reference Figure 2 and Figure 3The guide roller 13 is positioned on one side of the pulling roller 12, parallel to the pulling roller 12. The irradiation chamber 14 is located on the side of the guide roller 13 away from the pulling roller 12. The entrance to the irradiation chamber 14 is located on the side closer to the guide roller 13, and a feed roller 141 is positioned at the entrance. Under the action of the pulling roller 12, the flat POF film passes through the guide roller 13 and the feed roller 141, entering the irradiation chamber 14. The POF film undergoes radiation treatment. Radiation crosslinking can improve defects in the POF heat-shrinkable film and enhance its performance. The irradiated POF film is then transported to the next step for further processing.

[0033] Since the irradiation chamber 14 is a high-temperature and high-pressure environment, the high temperature and high pressure easily cause gas to be generated inside the film in the irradiation chamber 14. Then, under the action of the high pressure in the irradiation chamber 14, the gas in the film in the irradiation chamber 14 will be squeezed out from the entrance of the irradiation chamber 14. Since the film outside the entrance of the irradiation chamber 14 is relatively soft, the pressure inside the film is relatively low, and the irradiation chamber 14 is a high-pressure environment, the gas squeezed out of the film outside the irradiation chamber 14 can no longer flow back into the irradiation chamber 14. Therefore, gas will gradually accumulate inside the film at the entrance of the irradiation chamber 14, thereby forming a film bubble 7; if the film bubble 7 is too large, the POF film will not be able to enter the irradiation chamber 14 smoothly. If the POF film is taken out for exhaust, and then the film is re-pulled and the machine is restarted for film preparation, the process will be more complicated, and the process of re-pulling and restarting the machine will increase the cost and waste a lot.

[0034] Reference Figure 3 In order to quickly exhaust the gas in the film bubble 7 without stopping the machine, an automatic exhaust structure is provided, which includes a squeezing mechanism 2 and an exhaust mechanism 3. The squeezing mechanism 2 can squeeze the gas in the film bubble 7 into the exhaust mechanism 3, and then the gas is exhausted through the exhaust mechanism 3, thereby achieving exhaust of the film bubble 7 at the entrance of the irradiation chamber 14.

[0035] Reference Figure 3 and Figure 4 , the extrusion mechanism 2 is provided with two groups, which are respectively located on the left and right sides of the width direction of the film bubble 7 at the entrance of the irradiation chamber 14. The extrusion mechanism 2 includes a mounting seat 21, an extrusion assembly 22, an adjustment assembly 23 and a linear drive 24. A bracket 8 is provided on the outside of the entrance of the irradiation chamber 14, and the linear drive 24 is a cylinder, and the linear drive 24 is fixedly connected to the bracket 8. In other embodiments, the linear drive 24 can also be an oil cylinder or an electric push rod. The mounting seat 21 is fixedly connected to the movable end of the linear drive 24, so that the linear drive 24 can drive the mounting seat 21 to slide along the length direction of the film bubble 7 outside the entrance of the irradiation chamber 14.

[0036] The extrusion assembly 22 is mounted on the mounting base 21; each extrusion mechanism 2 includes two extrusion assemblies 22, symmetrically positioned above and below the mounting base 21. The extrusion assembly 22 comprises a mounting block 221 and an extrusion roller 222. The mounting base 21 is provided with a chute 211. A slider is fixedly connected to the sidewall of the mounting block 221. The slider slides within the chute 211, allowing the mounting block 221 to slide onto the mounting base 21. The ends of the extrusion roller 222 are rotatably connected to the mounting block 221, so that when the mounting block 221 slides along the chute 211, it drives the extrusion roller 222 with it.

[0037] Each extrusion mechanism 2 includes two adjustment assemblies 23, each corresponding to one of the two extrusion assemblies 22. Each adjustment assembly 23 comprises a spring 231, a protrusion 232, a first stop 233, a second stop 234, and a fixing member 235. The spring 231 is fixedly connected between the mounting block 221 and the inner wall of the slideway 211. When the spring 231 is compressed, it causes the two mounting blocks 221 on the same mounting seat 21 to slide toward each other. The protrusion 232 is fixedly connected to the mounting block 221. Both sides of the protrusion 232 have inclined surfaces, and the inclination direction and angle of the two inclined surfaces are the same.

[0038] The first stopper 233 and the second stopper 234 are both fixedly connected to the bracket 8. The first stopper 233 is located on the side closest to the guide roller 13, and the second stopper 234 is located on the side closest to the irradiation chamber 14. The first and second stops 233, 234 are located at either end of the movement path of the mounting base 21. The first and second stops 233, 234 are both provided with inclined surfaces on the sides adjacent to each other. The inclined surfaces on the first and second stops 233, 234 have the same inclination direction and degree as the inclined surface on the protrusion 232.

[0039] The fixing member 235 includes a first magnet block 2351 and a second magnet block 2352. The first magnet block 2351 is fixedly connected to the mounting block 221, and the second magnet block 2352 is fixedly connected to the inner wall of the chute 211. The magnetic poles of the first magnet block 2351 and the second magnet block 2352 on the side close to each other are in opposite directions. Therefore, when the first magnet block 2351 and the second magnet block 2352 abut, they can attract each other, thereby fixing the mounting block 221 to the mounting base 21.

[0040] Initially, the mounting base 21 is positioned near the guide roller 13, and the two mounting blocks 221 are secured to the mounting base 21 via fixing members 235. This allows the squeezing rollers 222 on the two mounting blocks 221 to be spaced apart. The POF film passes between the two squeezing rollers 222, and the two squeezing rollers 222 are separated from the POF film. After a large amount of gas accumulates in the POF film between the two squeezing rollers 222, forming a film bubble 7, the film bubble 7 and the squeezing rollers 222 remain separated. At this time, the linear drive member 24 can move the mounting seat 21 toward the side close to the irradiation chamber 14. When the mounting seat 21 moves, it drives the mounting block 221 and the protrusion 232 to move. When the inclined surface on the protrusion 232 is against the inclined surface on the second stop block 234, as the movable end of the linear drive member 24 extends, the two protrusions 232 will slide toward the side close to each other, and the first magnet block 2351 and the second magnet block 2352 will separate; then, under the action of the spring 231, the two squeezing rollers 222 can be pressed against the upper and lower sides of the film bubble 7 respectively.

[0041] The movable end of the linear drive member 24 is then retracted, causing the mounting seat 21 to slide toward the guide roller 13. The squeezing rollers 222 pressed against the upper and lower sides of the film bubble 7 can squeeze the gas in the film bubble 7 toward the guide roller 13. When the protrusion 232 moves to abut against the first stopper 233, the inclined surfaces of the protrusion 232 cooperate with the inclined surfaces of the first stopper 233, and as the movable end of the linear drive member 24 is retracted, the two protrusions 232 slide away from each other. The sliding of the protrusion 232 drives the mounting block 221 to slide until the first magnet 2351 on the mounting block 221 and the second magnet 2352 on the inner wall of the chute 211 engage, securing the mounting block 221 to the mounting seat 21 again. At this point, the exhaust extrusion action is complete, and the linear drive member 24 stops.

[0042] The protrusion 232 is located outside the slide groove 211 , so the first stopper 233 and the second stopper 234 are both outside the sliding area of ​​the mounting base 21 , and the setting of the first stopper 233 and the second stopper 234 will not affect the sliding of the mounting base 21 .

[0043] In other embodiments, the adjustment component 23 can also be configured as a finger cylinder fixedly mounted on the mounting base 21, with the two movable ends of the finger cylinder respectively fixedly connected to the two mounting blocks 221, and the cylinder drives the two mounting blocks 221 to slide in opposite directions, thereby achieving adjustment of the position of the squeezing roller 222.

[0044] To ensure synchronous rotation of the two squeeze rollers 222 during the degassing process, a gear 2221 is coaxially fixedly connected to the end of each squeeze roller 222. When the spring 231 forces the two squeeze rollers 222 to press against the upper and lower sides of the film bubble 7, the gears 2221 at the ends of the two squeeze rollers 222 mesh with each other. As a result, the two squeeze rollers 222 can rotate synchronously in opposite directions while sliding along the length of the film bubble 7, thereby improving the synchronization of the squeeze rollers 222 and ensuring effective degassing.

[0045] A flexible pad is also provided on the outside of the squeezing roller 222. The flexible pad is a rubber pad, which can protect the film bubble 7 and reduce the possibility of damaging the POF film during the exhaust process.

[0046] Reference Figure 5 The exhaust mechanism 3 includes an exhaust channel 31 and a pressure regulating valve 32. The exhaust channel 31 is arranged in the exhaust pipe, which is embedded in the extrusion die 11. There are multiple exhaust pipes arranged in a circular array. The bottom end of the exhaust pipe passes through the bottom end of the extrusion die 11, so that the bottom end of the exhaust pipe can be connected to the inside of the membrane tube 10 extruded from the bottom end of the extrusion die 11. In other embodiments, the exhaust channel 31 can also be an exhaust hole opened on the extrusion die 11. The pressure regulating valve 32 is fixedly connected to the extrusion die 11, and one end of the pressure regulating valve 32 is connected to the top of the exhaust channel 31. The pressure regulating valve 32 is used to keep the pressure in the membrane tube 10 extruded from the extrusion die 11 constant, so that the membrane tube 10 can expand and make the outer side of the membrane tube 10 abut against the inner wall of the cooling ring 15, thereby ensuring the cooling effect of the cooling ring 15 on the membrane tube 10. When the extrusion mechanism is in operation, the gas in the film bubble 7 outside the inlet of the irradiation chamber 14 is squeezed out, and the gas in the film bubble 7 enters the film tube 10 at the lower end of the extrusion die 11, which increases the pressure in the film tube 10. Therefore, the pressure regulating valve 32 can be opened to discharge part of the gas in the film tube 10, thereby keeping the pressure in the film tube 10 constant and completing the exhaust process.

[0047] Reference Figure 6 and Figure 7 In addition, both ends of the guide roller 13 and one of the pulling rollers 12 are equipped with annular venting grooves 4, which provide space for the POF film to vent. When the extrusion mechanism 2 is activated, it squeezes out the gas in the film bubble 7 outside the entrance of the irradiation chamber 14. The gas then flows along the film bubble 7 to the guide roller 13. Because the middle portion of the POF film is pressed against the guide roller 13, the bottom of the POF film at both ends can bulge into the venting grooves 4, creating spaces for internal gas flow on both sides of the POF film, facilitating the exhaust of gas from the POF film. The venting grooves 4 on the pulling roller 12 have the same function, allowing the gas in the film bubble 7 to flow smoothly into the film tube 10 and then be discharged through the pressure regulating valve 32.

[0048] It should be noted that the film tube 10 above the pulling roller 12 is relatively soft and has a relatively low internal pressure of 0.1-0.2 MPa, as it has just been cooled by the cooling ring 15. However, the POF film after passing through the pulling roller 12 is relatively far from the cooling ring 15 and has undergone a period of natural cooling, making this portion of the film relatively hard and having a slightly higher internal pressure of 0.3-0.5 MPa. Therefore, even if the pulling roller 12 and the guide roller 13 are provided with exhaust grooves 4 and a certain pressure is maintained in the film tube 10, the gas in the film tube 10 is unlikely to flow through the exhaust grooves 4 into the film bubble 7 outside the entrance of the irradiation chamber 14. Only when the squeezing mechanism 2 is activated, causing the squeezing rollers 222 pressed against both sides of the film bubble 7 to slide toward the side closer to the guide roller 13, can forced exhaust be performed, forcing the gas in the film bubble 7 to be forced out of the film tube 10.

[0049] The irradiation chamber 14 is also equipped with a sensor, a controller, and an alarm. The controller is electrically connected to the sensor and alarm, respectively. The sensor is a photoelectric or infrared sensor, with its detection end facing upward from the POF film outside the entrance of the irradiation chamber 14. When there is little gas inside the POF film outside the entrance of the irradiation chamber 14, the bubble 7 formed is small and the photoelectric sensor does not detect the presence of the bubble 7. When more gas accumulates in the bubble 7, the bubble 7 increases in volume, and the sensor can detect the presence of the bubble 7. The controller activates the alarm to sound an alarm, alerting the operator, who then promptly activates the linear drive 24 to expel the gas from the bubble 7 through the squeezing mechanism 2.

[0050] In other embodiments, the linear drive member 24 and the controller can also be electrically connected, so that when the sensor detects the presence of the membrane bubble 7, the linear drive member 24 can be driven by the controller to perform a reciprocating motion, thereby discharging the gas in the membrane bubble 7, further improving the degree of automation of the exhaust structure, and thus being more convenient.

[0051] The operating principle of Example 1 is as follows: When the volume of the film bubble 7 at the entrance of the irradiation chamber 14 is large, indicating that a large amount of gas has accumulated within the film bubble 7, the linear drive member 24 is activated, and the movable end of the linear drive member 24 extends, causing the linear drive member 24 to slide toward the side closer to the irradiation chamber 14. The sliding of the mounting seat 21 drives the mounting block 221 and the protrusion 232 to slide. When the inclined surface of the protrusion 232 contacts the inclined surface of the second stopper 234, the inclined surfaces cooperate to cause the two protrusions 232 to slide toward each other. The protrusion 232 drives the mounting block 221 to slide, separating the first magnet block 2351 and the second magnet block 2352. Then, under the action of the spring 231, the squeezing rollers 222 on the two mounting blocks 221 are pressed against the upper and lower sides of the film bubble 7, respectively. At this time, the gears 2221 on the two squeezing rollers 222 engage.

[0052] The movable end of the linear drive member 24 then retracts, driving the mounting seat 21 to slide toward the side near the guide roller 13. The sliding of the mounting seat 21 drives the extrusion roller 222, which, under the meshing action of the gear 2221, can cause the two extrusion rollers 222 to rotate in opposite directions, thereby ensuring the synchronous rotation of the two extrusion rollers 222. The extrusion rollers 222, pressed against both sides of the film bubble 7, squeeze out the gas within the film bubble 7 during the sliding process. Under the action of the exhaust groove 4, the gas within the film bubble 7 flows along both sides of the POF film into the film tube 10 at the lower end of the extrusion die 11. As the amount of gas discharged into the film tube 10 increases, the air pressure within the film tube 10 increases, and the regulating valve can be opened, allowing the excess gas in the film tube 10 to be discharged outward through the exhaust channel 31, thereby ensuring a constant pressure within the film tube 10 and completing the exhaust process.

[0053] When the mounting base 21 slides toward the side closer to the guide roller 13, it drives the mounting block 221 and the protrusion 232 to slide. When the inclined surface on the protrusion 232 and the inclined surface on the first stopper 233 collide, the inclined surfaces cooperate to cause the two protrusions 232 to slide away from each other, and the protrusion 232 drives the mounting block 221 to slide until the first magnet block 2351 on the mounting block 221 and the second magnet block 2352 on the mounting base 21 are attracted together, fixing the mounting block 221 to the mounting base 21. At this time, the squeezing rollers 222 on the two mounting blocks 221 are spaced apart on both sides of the POF film, and the squeezing rollers 222 and the POF film are in a separated state. At this point, the film bubble 7 is squeezed and exhausted once. Since the molding device 1 can still operate normally during the exhaust process, the impact of the exhaust process on the production process is reduced, which helps to reduce costs.

[0054] Example 2 Reference Figure 8 and Figure 9 This embodiment differs from the first embodiment in that the traction roller 12 in this embodiment is further provided with a partition mechanism 5, which includes an annular airbag 51 and an air pump 52. Two annular airbags 51 are provided, one disposed in each of the two exhaust grooves 4, with the inner walls of the annular airbags 51 fixedly connected to the inner walls of the exhaust grooves 4. The air pump 52 is provided on one side of the traction roller 12 and is in communication with the annular airbags 51.

[0055] When the squeezing mechanism 2 is not in operation, the air pump 52 fills the annular airbag 51 with air, so that the outer wall of the annular airbag 51 is flush with the outer wall of the traction roller 12. As a result, the middle part and both sides of the POF film passing between the two traction rollers 12 can be pressed into a flat shape, thereby blocking the bottom end of the film tube 10 and further reducing the possibility of gas in the film tube 10 flowing into the film bubble 7 through the exhaust groove 4. When the squeezing mechanism 2 is in operation, the air in the annular airbag 51 is extracted by the air pump 52, causing the annular airbag 51 to shrink. Therefore, during the forced exhaust process of the squeezing mechanism 2, the two sides of the POF film can bulge into the exhaust groove 4, thereby providing space for the gas inside the POF film to circulate and facilitate the smooth exhaust of the gas inside the POF film.

[0056] Because the traction roller 12 is designed to rotate, an air delivery assembly 6 is provided between the annular airbag 51 and the air pump 52 to facilitate the delivery of gas from the air pump 52. The air delivery assembly 6 comprises a connecting ring 61, an air delivery disc 62, and an air delivery pipe 63. The connecting ring 61 is fixedly connected to the inner wall of the annular airbag 51 and is coaxial with the traction roller 12. One end of the connecting ring 61 communicates with the interior of the annular airbag 51, while the other end of the connecting ring 61 is open. The air delivery disc 62 is disposed inside the connecting ring 61 and embedded in the traction roller 12, with the two traction rollers 12 being rotatably connected. The air delivery disc 62 contains a cavity for air flow. The outer side of the air delivery disc 62 is rotatably connected to the inner side of the connecting ring 61, and the cavity inside the air delivery disc 62 communicates with the opening inside the connecting ring 61. The air supply pipe 63 is fixedly connected to the inner side of the air supply disk 62 , and the air supply pipe 63 is communicated with the internal cavity of the air supply disk 62 ; one end of the air supply pipe 63 away from the air supply disk 62 is communicated with the air pump 52 .

[0057] Therefore, the air pump 52 can fill the annular airbag 51 with air through the air supply pipe 63, the air supply plate 62 and the connecting ring 61. When the traction roller 12 rotates, the annular airbag 51 and the connecting ring 61 can be driven to rotate, while the air supply plate 62, the air supply pipe 63 and the air pump 52 can remain stationary, thereby ensuring the delivery of air without affecting the rotation of the traction roller 12.

[0058] Since two annular airbags 51 are provided on each roller body, the air supply plates 62 corresponding to the two annular airbags 51 are connected to each other through a branch pipe 9. The branch pipe 9 is embedded in the interior of the roller body, and the branch pipe 9 and the roller body are rotatably connected, so that the two annular airbags 51 on the same roller body can be inflated or deflated at the same time.

[0059] The above are optional embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A POF film-forming automatic exhaust structure, arranged on a molding device (1), the molding device (1) comprising an extrusion die (11), a traction roller (12), a guide roller (13) and an irradiation chamber (14), the traction roller (12) being arranged on the extrusion side of the extrusion die (11), the guide roller (13) being arranged between the traction roller (12) and the irradiation chamber (14), so that the film extruded by the extrusion die (11) can be transported to the irradiation chamber (14) through the traction roller (12) and the guide roller (13) in sequence, characterized in that: include: A squeezing mechanism (2), the squeezing mechanism (2) being arranged outside the entrance of the irradiation chamber (14), the squeezing mechanism (2) comprising a mounting seat (21), a squeezing assembly (22), an adjusting assembly (23) and a linear drive member (24), the squeezing assembly (22) and the adjusting assembly (23) both being arranged on the mounting seat (21), the squeezing assembly (22) being provided with two groups, the two squeezing assemblies (22) being respectively used to press against two sides of the film between the guide roller (13) and the irradiation chamber (14) The adjusting component (23) is used to drive the two extrusion components (22) to move in opposite directions, so that the two extrusion components (22) are respectively pressed against the two sides of the film or are arranged at intervals on the two sides of the film, the linear drive member (24) is arranged on one side of the irradiation chamber (14), and the mounting seat (21) is fixedly arranged on the movable end of the linear drive member (24), so that the linear drive member (24) drives the mounting seat (21) and the extrusion component (22) to slide along the length direction of the film and squeeze out the gas in the film bubble (7); An exhaust mechanism (3), the exhaust mechanism (3) comprising an exhaust channel (31) and a pressure regulating valve (32), the exhaust channel (31) and the pressure regulating valve (32) both being arranged on the extrusion die (11), the exhaust channel (31) being arranged inside the extrusion die (11), one end of the exhaust channel (31) passing through the extrusion side of the extrusion die (11), and the other end of the exhaust channel (31) being connected to the pressure regulating valve (32), so that a constant pressure is maintained in the film tube (10) on the extrusion side of the extrusion die (11); The pulling roller (12) and the guide roller (13) are both provided with an exhaust groove (4), and the exhaust groove (4) is an annular groove, so that when the extrusion mechanism (2) is in operation, one side of the film can be pressed against the bottom wall of the exhaust groove (4) to provide space for the flow of gas in the film, and the gas in the film bubble (7) outside the inlet of the irradiation chamber (14) can flow into the film tube (10) at the end of the extrusion die (11) through the exhaust groove (4). When the pressure in the film tube (10) increases, the exhaust valve will open to discharge excess gas.

2. The POF film according to claim 1 is made into an automatic exhaust structure, characterized in that: Two air vents (4) are provided on the traction roller (12) and are located at two ends of the traction roller (12), respectively; and two air vents (4) are provided on the guide roller (13) and are located at two ends of the guide roller (13), respectively.

3. The POF film according to claim 1 is made into an automatic exhaust structure, characterized in that: The extrusion assembly (22) comprises a mounting block (221) and an extrusion roller (222); the mounting block (221) is slidably disposed on the mounting seat (21); the extrusion roller (222) is rotatably connected to the mounting block (221); and the sides of the two extrusion rollers (222) that are close to each other can respectively press against two sides of the film.

4. The POF film-made automatic exhaust structure according to claim 3, characterized in that: A gear (2221) is coaxially fixedly connected to each of the squeezing rollers (222); when the two squeezing rollers (222) are respectively pressed against two sides of the film, the two gears (2221) mesh with each other.

5. The POF film-made automatic exhaust structure according to claim 3, characterized in that: A flexible pad is provided on the outer side of the squeezing roller (222).

6. The POF film-made automatic exhaust structure according to claim 3, characterized in that: The adjustment assembly (23) comprises a spring (231), a protrusion (232), a first stopper (233), a second stopper (234) and a fixing component (235); the spring (231) is connected between the mounting block (221) and the mounting seat (21) so that the two mounting blocks (221) on the same mounting seat (21) tend to slide towards one side approaching each other; the protrusion (232) is fixedly connected to the mounting block (221); and the protrusion (232) is fixedly connected to the mounting block (221). The first stopper (233) and the second stopper (234) are respectively arranged at two ends of a moving path of the mounting seat (21); the first stopper (233) and the second stopper (234) are both provided with an inclined surface that matches the inclined surface on the protrusion (232); the fixing component (235) is arranged between the mounting block (221) and the mounting seat (21) and is used to fix the mounting block (221) to the mounting seat (21); When the protrusion (232) abuts against the first stopper (233), the two protrusions (232) slide towards a side away from each other, the mounting block (221) is fixed to the mounting seat (21) via the fixing component (235), and the squeezing roller (222) and the film are separated; when the protrusion (232) abuts against the second stopper (234), the two protrusions (232) slide towards a side close to each other, and the two squeezing rollers (222) are respectively pressed against two sides of the film.

7. The POF film-made automatic exhaust structure according to claim 6, characterized in that: The fixing component (235) comprises a first magnet block (2351) and a second magnet block (2352); the first magnet block (2351) is fixedly connected to the mounting block (221); the second magnet block (2352) is fixedly connected to the mounting seat (21); and the magnetic poles of the first magnet block (2351) and the second magnet block (2352) on a side close to each other have opposite directions.

8. The POF film-made automatic exhaust structure according to claim 1, characterized in that: The traction roller (12) is provided with a partition mechanism (5), the partition mechanism (5) comprising an annular airbag (51) and an air pump (52), the annular airbag (51) being fixedly connected to the exhaust groove (4), when the annular airbag (51) is filled with air, the outer side of the annular airbag (51) is flush with the outer surface of the traction roller (12), the air pump (52) is arranged on one side of the traction roller (12), the air pump (52) is connected to the annular airbag (51), and when the extrusion mechanism (2) is in a stationary state, the annular airbag (51) is filled with air and pressed against one side of the film.

9. The POF film-made automatic exhaust structure according to claim 8, characterized in that: An air supply assembly (6) is provided between the annular airbag (51) and the air pump (52), the air supply assembly (6) comprising a connecting ring (61), an air supply disc (62) and an air supply pipe (63), the connecting ring (61) being fixedly connected to the inner wall of the annular airbag (51), the connecting ring (61) being in communication with the annular airbag (51), the air supply disc (62) being embedded in the traction roller (12), the air supply disc (62) being provided with a cavity for accommodating air, the air supply disc (62) and the connecting ring (61) being rotatably connected and in communication with each other, and the air supply pipe (63) being fixedly connected to the air supply disc (62) and being in communication with the air pump (52).

10. The POF film-made automatic exhaust structure according to claim 1, characterized in that: A sensor and an alarm are arranged outside the irradiation chamber (14), and the sensor and the alarm are electrically connected.

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