Soft package bag fixed-length pulling device and use method thereof

Abstract

The application provides a soft packaging bag fixed-length material drawing device, and relates to the technical field of packaging bag production. The device comprises a frame and an array of pinch rollers. The frame is connected with a reciprocating pulling frame. The reciprocating pulling frame is connected with a plurality of pulling roller groups. The frame is provided with a linear transmission module. The driving sliding adjustment frame is connected with a conical surface transmission body. The conical surface transmission body is connected with the reciprocating pulling frame through a transmission frame and an elastic connection mechanism. The frame is provided with an elastic compensation frame with a compensation roller, a linkage module with a ring-shaped shaping belt, and a semiconductor refrigeration plate. The reciprocating pulling frame is driven by the conical surface transmission body to realize the fixed-length stretching of the bag film through reciprocating linear motion. The intermittent rotation of the pinch roller group and the pulling roller group is matched to realize the timing cooperation of feeding and stretching. At the same time, the hot stretching is realized by using an electric heating assembly, and the rapid cooling and shaping are realized by using the semiconductor refrigeration plate and the ring-shaped shaping belt, thereby effectively solving the problems of easy shrinkage of the size after stretching and uneven stress of the existing device.

Description

Technical Field

[0001] This invention relates to the field of packaging bag production technology, specifically to a fixed-length feeding device for flexible packaging bags and its usage method. Background Technology

[0002] Flexible packaging refers to packaging whose shape can change after the contents are filled or removed. Various bags, boxes, sleeves, and seals made of paper, aluminum foil, fiber, plastic film, and their composites all fall under the category of flexible packaging. Flexible packaging bags are broadly classified into two categories: stretch wrap packaging and various types of bags. Stretch wrap packaging consists of plastic film that has not yet formed its packaging shape; the film is simply wrapped around one or more products to be packaged and fixed in place in some way. Plastic bags are shaped before or during product loading, most commonly by stretching plastic material to a fixed length to form the flexible packaging bag shape. Flexible packaging bag stretching devices are specialized equipment used in the preparation of flexible packaging films such as plastic composite films.

[0003] Currently, most of the existing flexible packaging bag stretching devices in the industry are designed with pure mechanical stretching as the core concept. They stretch the bag film by the difference in linear speed between the feeding roller group and the stretching roller group, and complete the initial shaping with simple roller pressing. The overall structure only includes a frame, a continuous transmission roller group, a single drive mechanism and a simple shaping component. It does not consider the influence of the material properties of the plastic composite film on the stretching and shaping effect, which leads to poor dimensional stability of the bag film after stretching, the inability to eliminate shrinkage stress, the lack of durability of the fixed length effect, and uneven stress during the stretching process, which easily leads to problems such as local overstretching and uneven thickness. Based on this, the present invention provides a fixed-length material pulling device for flexible packaging bags and its usage method to solve the technical problems mentioned in the background art. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art by providing a fixed-length stretching device for flexible packaging bags and its usage method to solve the problem that the film body in the existing device is subjected to uneven force during the stretching process, which easily leads to local overstretching or uneven thickness.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A flexible packaging bag fixed-length feeding device includes a frame, on which a main controller is fixedly mounted, and further includes: Multiple sets of pinch rollers are arrayed on a frame, and bag film is pinched on the multiple sets of pinch rollers; A reciprocating traction frame is slidably connected to a frame. A reciprocating spring is provided between the reciprocating traction frame and the frame. Multiple sets of traction rollers are connected to the reciprocating traction frame at positions parallel to the pinch roller sets. A linear drive module is fixedly mounted on a frame. A sliding adjustment frame is connected to the linear drive module. The sliding adjustment frame is slidably connected to the frame. A conical drive body is rotatably connected to the sliding adjustment frame. The transmission frame is connected to the conical transmission body and is provided with an elastic connection mechanism between it and the reciprocating traction frame; The rotating shaft is rotatably connected to the frame and is connected to the conical transmission body for transmission. An elastic compensation frame is slidably connected to a frame. A compensation spring is provided between the elastic compensation frame and the frame. A compensation roller connected to the bag film transmission is rotatably connected to the elastic compensation frame. The compensation roller is located between the pinch roller group and the traction roller group. An electric heating table is also fixedly installed on the elastic compensation frame. A linkage module is set on the frame. The linkage module is provided with two symmetrically arranged annular shaping belts. A shaping gap that cooperates with the bag film is provided between the two annular shaping belts. A semiconductor cooling plate is installed on the frame at a position corresponding to the inner side of the two annular shaping belts. The transmission mechanism, mounted on the frame, is used to drive the pinch roller group and the traction roller group to rotate synchronously and intermittently, as well as to drive the rotating shaft and the linkage module to rotate at a constant speed.

[0006] As a preferred technical solution of the present invention, the multiple sets of pinch roller groups and the multiple sets of traction roller groups cooperate with each other. Each set of pinch roller groups and traction roller groups includes two symmetrically arranged guide rollers. A first linkage gear is installed on each of the two guide rollers. The two first linkage gears mesh with each other. A rubber sleeve is sleeved on each of the two guide rollers. A conveying gap that cooperates with the bag film is fixedly provided between the rubber sleeves. An electric heating rod is integrated and installed inside the guide roller.

[0007] As a preferred technical solution of the present invention, the cross-section of the conical transmission body is an isosceles trapezoid, and an arc-shaped transmission cone is fixedly provided on the conical transmission body. The arc-shaped transmission cone is connected to the transmission frame. A shaft hole that is slidably connected to the rotating shaft is opened at the axial position of the conical transmission body. The cross-sections of the shaft hole and the rotating shaft are both regular hexagons.

[0008] As a preferred embodiment of the present invention, the transmission mechanism includes a first transmission belt and a second transmission belt. Two adjacent pinch roller groups are connected by the first transmission belt, and two adjacent traction roller groups are connected by the second transmission belt. A double-headed motor is fixedly mounted on the frame. One end of the double-headed motor is fixedly connected to a rotating shaft, and the other end of the double-headed motor is connected to an intermittent toothed gear. The intermittent toothed gear meshes with an intermittent gear, which is rotatably connected to the frame via a connecting shaft. A tensioning element is provided on the frame. A third transmission belt is wound around a guide roller in one of the traction roller groups, a guide roller in one of the pinch roller groups, the connecting shaft, and the tensioning element.

[0009] As a preferred technical solution of the present invention, the tensioning member includes a tensioning slider slidably connected to the frame, a tensioning spring is installed on the side of the tensioning slider, the other end of the tensioning spring is fixedly connected to the frame, a tensioning pulley is rotatably connected to the tensioning slider, and the tensioning pulley is driven by a third transmission belt.

[0010] As a preferred technical solution of the present invention, the elastic connection mechanism includes a T-shaped limiting rod fixed on the transmission frame, the T-shaped limiting rod being slidably connected to the reciprocating traction frame, the axis of the T-shaped limiting rod being perpendicular to the rotation axis of the conical transmission body, and a compression spring being sleeved on the T-shaped limiting rod at a position corresponding to the reciprocating traction frame and the transmission frame.

[0011] As a preferred technical solution of the present invention, the linkage module includes two first transmission rollers and two second transmission rollers rotatably connected to the frame, wherein a second linkage gear is installed on one of the first transmission rollers and one of the second transmission rollers, and the two second linkage gears mesh with each other. A fourth transmission belt is drivenly connected to one of the output shafts of the dual-head motor, and the fourth transmission belt is drivenly connected to one of the first transmission rollers.

[0012] A method for using a fixed-length feeding device for flexible packaging bags includes the following steps: S1. Inserting the bag film: The bag film made of plastic composite film is inserted through the multiple pinch roller groups and traction roller groups arranged in an array on the frame in a Z-shaped manner. S2. Heating and tensioning: Start the device to make the electric heating rods in the pinch roller group and the traction roller group work to preheat the inserted bag film. At the same time, the compensation roller on the elastic compensation frame elastically presses against the bag film under the action of the compensation spring to keep the bag film in a taut state. S3. Intermittent feeding and continuous pulling: The transmission mechanism drives the pinch roller group and the pulling roller group to rotate synchronously and intermittently, realizing the intermittent feeding of the bag film. At the same time, the transmission mechanism drives the rotating shaft to rotate at a constant speed, which drives the conical transmission body to rotate. The conical transmission body, through its arc-shaped transmission cone surface and the transmission frame, drives the reciprocating pulling frame and the pulling roller group on it to perform reciprocating linear motion through the elastic connection mechanism, so as to stretch the bag film at a fixed stroke when the pinch roller group stops intermittently. S4. Stretch adjustment: The main controller controls the linear transmission module to drive the sliding adjustment frame to slide linearly along the frame, changing the transmission connection position between the conical transmission body and the transmission frame, thereby adjusting the single reciprocating stroke of the reciprocating traction frame to achieve fixed length control of the single stretch length of the bag film. S5. High-temperature temporary shaping: During the stretching process, the electric heating rods in the guide rollers and the electric heating table on the elastic compensation frame work together to raise the temperature of the bag film, causing the molecular chains of the bag film to rearrange under stress, thereby achieving temporary shaping of the film. S6. Cooling, shaping and unloading: The bag film, after being stretched and temporarily shaped, enters the shaping gap formed by two symmetrically arranged annular shaping belts. The transmission mechanism drives the linkage module to drive the two annular shaping belts to rotate synchronously in opposite directions at a uniform speed, performing roll forming on the bag film. At the same time, the semiconductor cooling plate set on the frame works, transferring low temperature to the surface of the bag film through the annular shaping belts, so that it can be cooled quickly, and finally output bag film substrate with stable dimensions.

[0013] The beneficial effects of this invention are: 1. This invention utilizes the synergistic action of the electric heating rods in the pinch roller group and the traction roller group and the electric heating table on the elastic compensation frame to heat the bag film during the traction process, so that the molecular chains of the composite film rearrange in an orderly manner under the tensile stress, completing the high-temperature temporary shaping. Then, through the linkage between the annular shaping belt and the inner semiconductor cooling plate, the bag film is rapidly cooled, allowing the rearranged molecular chains to be quickly fixed and formed, realizing cold locking shape, fundamentally eliminating the shrinkage stress of the film, ensuring that the stretched bag film maintains dimensional stability for a long time, and making the fixed length effect durable; 2. This invention arranges the bag film in a Z-shape through an array of pinch rollers and traction rollers, achieving multi-layer synchronous segmented material pulling. This effectively reduces stress concentration issues associated with single-layer material pulling. Simultaneously, a linkage mode of intermittent feeding and continuous pulling is established through the transmission mechanism. This allows the reciprocating traction frame to perform fixed-stroke stretching of the bag film during the roller group's stop phase. The roller group's feeding stroke and the traction frame's stretching stroke complement each other. With the compensation roller's elastic tension and stretching amount automatically compensated by the compensation spring, the bag film remains in a controllable and uniform tension state throughout the material pulling process. This effectively avoids local overstretching and uneven thickness, improving the uniformity and dimensional consistency of the bag film stretching.

[0014] 3. This invention drives the sliding adjustment frame to slide through a linear transmission module, changing the transmission connection position between the conical transmission body and the transmission frame. By utilizing the isosceles trapezoidal structural characteristics of the conical transmission body, the single reciprocating stroke of the reciprocating traction frame is adjusted, thereby achieving flexible fixed-length control of the bag film stretching amount and adapting to the processing needs of flexible packaging bags of different specifications. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of a fixed-length material pulling device for flexible packaging bags according to the present invention; Figure 2 For the present invention Figure 1 A magnified schematic diagram of the local structure at point A; Figure 3 This is a schematic diagram of the reciprocating traction frame and reciprocating spring of the present invention; Figure 4 For the present invention Figure 3 A magnified view of the structure at point B in the middle; Figure 5This is a cross-sectional schematic diagram of the pinch roller assembly and the semiconductor cooling plate of the present invention; Figure 6 For the present invention Figure 5 A magnified schematic diagram of the local structure at point C; Figure 7 This is a schematic diagram of the structure of the second transmission roller and the linear transmission module of the present invention; Figure 8 This is a schematic diagram of the T-shaped limiting rod and transmission frame of the present invention; Figure 9 This is a schematic diagram of the structure of the electric heating table and the elastic compensation frame of the present invention; Figure 10 This is a schematic diagram of the reciprocating traction frame and transmission frame of the present invention.

[0016] The attached diagram lists the components represented by each number as follows: 1. Frame; 2. Pinch roller assembly; 3. Reciprocating traction frame; 4. Reciprocating spring; 5. Traction roller assembly; 6. Linear transmission module; 7. Sliding adjustment frame; 8. Conical transmission body; 9. Transmission frame; 10. Rotary shaft; 11. Elastic compensation frame; 12. Compensating spring; 13. Bag film; 14. Compensating roller; 15. Heating table; 16. Annular shaping belt; 17. Semiconductor cooling plate; 18. First linkage gear; 19. Dual-head motor; 20. Connecting shaft; 21. Intermittent toothed gear; 22. Intermittent gear; 23. Tensioning slider; 24. Tensioning spring; 25. Tensioning pulley; 26. T-shaped limit rod; 27. Compression spring; 28. First transmission roller; 29. ​​Second transmission roller; 30. Second linkage gear; 31. Main controller. Detailed Implementation

[0017] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0018] The present invention provides the following preferred embodiments. like Figure 1-10 As shown, a flexible packaging bag fixed-length pulling device includes a frame 1, and further includes: Multiple sets of pinch rollers 2 are arrayed on frame 1, and bag film is pinched on the multiple sets of pinch rollers 2; A reciprocating traction frame 3 is slidably connected to the frame 1. A reciprocating spring 4 is provided between the reciprocating traction frame 3 and the frame 1. Multiple sets of traction roller groups 5 are connected to the reciprocating traction frame 3 at a position parallel to the pinch roller group 2. Multiple sets of pinch roller groups 2 and multiple sets of traction roller groups 5 cooperate with each other. Each set of pinch roller group 2 and traction roller group 5 includes two symmetrically arranged guide rollers. A first linkage gear 18 is installed on each of the two guide rollers. The two first linkage gears 18 mesh with each other. A rubber sleeve is fitted on each of the two guide rollers. A conveying gap that cooperates with the bag film 13 is fixedly set between the rubber sleeves. An electric heating rod is integrated inside the guide roller. The bag film 13 is a flexible packaging bag film. Specifically, the bag film 13 is a plastic composite film, specifically a PE / PP composite film. When the bag film 13 is laid out, it passes through the pinch roller group 2 and the traction roller group 5 in a Z-shaped arrangement. The bag film 13 passes through the pinch roller group 2 and the traction roller group 5 arranged in a Z-shaped arrangement in a vertical direction, realizing multi-layer synchronous segmented material pulling of the bag film 13. This makes the bag film 13 more uniformly stressed during the material pulling process and avoids the problem of excessive local stretching and uneven thickness of the film caused by single-layer material pulling. At the same time, multi-layer synchronous operation greatly improves the material pulling efficiency of the flexible packaging film 13. With the rubber sleeve on the guide roller, it can not only ensure the stable clamping of the film 13, but also avoid scratching the surface of the film 13 during the clamping process. The electric heating rod integrated in the guide roller can preheat the film 13, so that the film 13 is in a stretchable state, laying the foundation for subsequent fixed-length stretching and shaping. Linear transmission module 6 is fixedly mounted on frame 1. A sliding adjustment frame 7 is connected to the linear transmission module 6. The sliding adjustment frame 7 is slidably connected to frame 1. A conical transmission body 8 is rotatably connected to the sliding adjustment frame 7. The linear transmission module 6 is a ball screw linear module, including a screw, a nut seat, and a servo motor. The screw is rotatably connected to the frame 1, and the nut seat is fixedly connected to the sliding adjustment frame 7. The servo motor drives the screw to rotate and drives the sliding adjustment frame 7 to slide linearly along the horizontal guide rail of the frame 1. The transmission frame 9 is equipped with an elastic connection mechanism between itself and the reciprocating traction frame 3, and the transmission frame 9 is connected to the conical transmission body 8 in a transmission connection. The rotating shaft 10 is rotatably connected to the frame 1 and is connected to the conical transmission body 8. The cross-section of the conical transmission body 8 is an isosceles trapezoid. An arc-shaped transmission cone is fixedly provided on the conical transmission body 8. The arc-shaped transmission cone is connected to the transmission frame 9. A shaft hole is opened at the axial position of the conical transmission body 8 to slide and connect with the rotating shaft 10. The cross-sections of the shaft hole and the rotating shaft 10 are both regular hexagons. Specifically, the linear transmission module 6 can drive the sliding adjustment frame 7 to slide along the frame 1, thereby changing the transmission connection position between the conical transmission body 8 and the transmission frame 9. Since the conical transmission body 8 is an isosceles trapezoidal structure, different transmission connection positions correspond to different transmission strokes, ultimately changing the single reciprocating stroke of the reciprocating traction frame 3, realizing flexible adjustment of the single or single-layer stretch of the bag film 13, and meeting the fixed-length processing requirements of the bag film 13 for different specifications of soft packaging bags. The conical transmission body 8 and the rotating shaft 10 adopt a sliding connection between the regular hexagonal shaft hole and the shaft, which ensures that the rotating shaft 10 drives the conical transmission body 8 to rotate at a uniform speed without affecting the position adjustment of the conical transmission body 8. The elastic connection mechanism includes a T-shaped limiting rod 26 fixed on the transmission frame 9. The T-shaped limiting rod 26 is slidably connected to the reciprocating traction frame 3. The axis of the T-shaped limiting rod 26 is perpendicular to the rotation axis of the conical transmission body 8. A compression spring 27 is sleeved on the T-shaped limiting rod 26 at a position corresponding to the reciprocating traction frame 3 and the transmission frame 9. The T-shaped limiting rod 26 provides precise guidance and limiting for the relative movement of the reciprocating traction frame 3 and the transmission frame 9, preventing them from deviating during transmission. The compression spring 27 sleeved on the T-shaped limiting rod 26 always provides elastic compression force to the transmission frame 9 in the direction of the conical transmission body 8, so that when the linear transmission module 6 adjusts the position of the conical transmission body 8, the transmission frame 9 can always be closely fitted with the arc-shaped transmission cone surface of the conical transmission body 8, stably maintaining the transmission relationship between the two, ensuring that the conical transmission body 8 can accurately drive the transmission frame 9 and the reciprocating traction frame 3 to perform reciprocating linear motion when rotating, avoiding the pulling stroke error caused by transmission gap, and ensuring the accuracy of fixed-length stretching of the bag film 13; Multiple arrays of elastic compensation frames 11 are arranged, each elastic compensation frame 11 is slidably connected to the frame 1, a compensation spring 12 is installed between the elastic compensation frame 11 and the frame 1, a compensation roller 14 that is rotatably connected to the elastic compensation frame 11 and is connected to the bag film 13, an electric heating table 15 is fixedly installed on each elastic compensation frame 11, and the compensation roller 14 is arranged between the pinch roller group 2 and the traction roller group 5. A main controller 31 is fixedly installed on the frame 1; the main controller 31 is a PLC controller, which is electrically connected to the electric heating rod, the electric heating table 15, the semiconductor cooling plate 17, the linear transmission module 6, and the dual-head motor 19 respectively, to realize full-process automated control and temperature closed-loop regulation. The elastic compensation frame 11 is elastically connected to the frame 1 through the compensation spring 12, so that the compensation roller 14 can always elastically press against the bag film 13 between the pinch roller group 2 and the traction roller group 5, automatically compensating for the stretching and slack of the bag film 13 during the stretching process, ensuring that the bag film 13 is in a taut state throughout the pulling process, and avoiding the problem of inaccurate stretching and positioning caused by the slack of the bag film 13. The electric heating table 15 on the elastic compensation frame 11 works in conjunction with the electric heating rod inside the guide roller to precisely control the temperature at 70-80℃. This temperature allows the molecular chains of the PE / PP composite film to rearrange under tensile stress, achieving temporary shaping of the film. This solves the problems of the inability to eliminate the shrinkage stress of the molecular chains after low-temperature stretching and the poor length-fixing effect, while avoiding the drawbacks of high temperature causing the film to melt and deform, affecting the forming quality of the flexible packaging bag, thus providing a good foundation for the subsequent final shaping. The linkage module is set on the frame 1. The linkage module is provided with two symmetrically arranged annular shaping belts 16. A shaping gap that cooperates with the bag film is provided between the two annular shaping belts 16. A semiconductor cooling plate 17 is installed on the frame 1 at the position corresponding to the inner side of the two annular shaping belts 16. The semiconductor cooling plate 17, which is set on the inner side of the annular shaping belt 16 on the frame 1, sets the working temperature to 10-15℃. The two symmetrically arranged annular shaping belts 16 form a shaping gap that adheres to the surface of the bag film 13 during the final discharge stage. After being stretched and temporarily shaped at high temperature, the bag film 13 passes through the gap at a uniform speed. The annular shaping belt 16 achieves full-process roll forming of the bag film 13 through continuous and uniform clamping force, which can effectively avoid the problems of warping, wrinkling and local shrinkage of the bag film 13 due to the release of its own stress during the discharge process, and ensure the flatness and dimensional regularity of the bag film 13 surface. Simultaneously, the annular shaping belt 16 and the inner semiconductor cooling plate 17 work together. The low temperature generated by the semiconductor cooling plate 17 is quickly transferred to the surface of the bag film 13 through the annular shaping belt 16, realizing the rapid cooling of the bag film 13 from the temporary shaping temperature of 80℃ to the room temperature. This allows the rearranged PE / PP composite film molecular chains after stretching to be quickly fixed and formed, completing the final cold-state locking shape, eliminating the shrinkage stress of the bag film 13, and ensuring that the bag film 13 can maintain the dimensional accuracy after being stretched for a long time after being discharged. This provides a film substrate with uniform size and stable shape for subsequent processes such as cutting and bag making of flexible packaging bags, improving the overall processing quality of the finished flexible packaging bags.

[0019] The transmission mechanism, set on the frame 1, is used to drive the pinch roller group 2 and the traction roller group 5 to rotate synchronously and intermittently, and to drive the rotating shaft 10 and the linkage module to rotate at a constant speed. The transmission mechanism includes a first transmission belt and a second transmission belt. Two adjacent pinch roller groups 2 are connected by the first transmission belt, and two adjacent traction roller groups 5 are connected by the second transmission belt. A dual-head motor 19 is fixedly mounted on the frame 1. One end of the dual-head motor 19 is fixedly connected to the rotating shaft 10. An intermittent toothed gear 21 is connected to the other end of the dual-head motor 19. The intermittent toothed gear 21 is meshed with an intermittent gear 22. The intermittent gear 22 is rotatably connected to the frame 1 through the connecting shaft 20. A tensioning element is provided on the frame 1. A third transmission belt is wound between a guide roller in the traction roller group 5, a guide roller in the pinch roller group 2, the connecting shaft 20, and the tensioning element.

[0020] The continuous reciprocating linear motion of the reciprocating traction frame 3 and the synchronous intermittent rotation of the guide roller work together to form a processing mode of intermittent feeding, continuous stretching, and precise length setting. Compared with the continuous feeding and stretching method of traditional material pulling equipment, this method allows the bag film 13 to be stably stretched by the reciprocating traction frame 3 during the intermittent stop phase of the guide roller. This avoids the problem of uncontrolled stretching and dimensional deviation caused by the superposition of forces on the bag film 13 during continuous feeding and stretching. Furthermore, the continuous motion of the reciprocating traction frame 3 achieves uniform and even stretching of the bag film 13, effectively solving the problem of local overstretching and uneven thickness of the film that is prone to occur in single-layer material pulling. Meanwhile, the rhythm of their movements is highly matched through the precise control of the intermittent toothed gear 21 and the conical transmission body 8. The feeding stroke of the intermittent rotation of the guide roller and the stretching stroke of the reciprocating traction frame 3 complement each other, so that the bag film 13 is always in a controllable tension stretching state throughout the entire pulling process. This not only improves the accuracy and consistency of the fixed-length stretching of the bag film 13, but also enables the stable realization of the multi-layer synchronous pulling operation mode, which greatly improves the processing efficiency while ensuring the stretching quality of the film. Furthermore, this coordination method allows the feeding and stretching actions of the bag film 13 to be independent yet precisely linked. Combined with the automatic compensation function of the elastic compensation frame 11, it can effectively offset the small gap errors in the transmission process of the equipment, further improving the accuracy of fixed-length material pulling.

[0021] The tensioning component includes a tensioning slider 23 slidably connected to the frame 1, a tensioning spring 24 mounted on the side of the tensioning slider 23, the other end of the tensioning spring 24 being fixedly connected to the frame 1, and a tensioning pulley 25 rotatably connected to the tensioning slider 23, which is connected to the third transmission belt.

[0022] The tensioning component, through the tensioning spring 24, drives the tensioning pulley 25 to constantly press against the third transmission belt, which can automatically compensate for the slack of the third transmission belt, ensure the transmission tension of the third transmission belt, avoid the problem of reduced transmission accuracy caused by transmission belt slippage, ensure the synchronization and accuracy of the intermittent rotation of each roller group, and improve the overall length drawing processing accuracy of the equipment. The linkage module includes two first transmission rollers 28 and two second transmission rollers 29 rotatably connected to the frame 1. A second linkage gear 30 is installed on one of the first transmission rollers 28 and one of the second transmission rollers 29. The two second linkage gears 30 mesh with each other. A fourth transmission belt is driven to one of the output shafts of the dual-head motor 19. The fourth transmission belt is driven to one of the first transmission rollers 28.

[0023] Two first drive rollers 28 and two second drive rollers 29 drive the corresponding annular shaping belts 16 respectively. The meshing of the second linkage gears 30 ensures the synchronous reverse transmission of the two annular shaping belts 16, making the clamping force of the shaping seam on the bag film 13 more uniform and the transmission more stable. The dual-head motor 19 directly drives the linkage module through the fourth transmission belt, forming an integrated power system with the overall transmission mechanism. This reduces the need for additional drive components, simplifies the equipment structure, and lowers the equipment failure rate and maintenance costs. Meanwhile, the continuous transmission of the annular shaping belt 16 enables continuous shaping of the bag film 13, which works in efficient coordination with the intermittent material pulling process at the front end, realizing continuous processing of fixed-length material pulling and shaping of the flexible packaging bag film 13, and greatly improving the overall production efficiency.

[0024] A method for using a fixed-length feeding device for flexible packaging bags includes the following steps: S1. Insert the bag film: The bag film 13 made of plastic composite film is inserted through the multiple pinch roller groups 2 and the traction roller group 5 arranged in an array on the frame 1 in a Z-shaped manner. S2. Heating and tensioning: Start the device to make the electric heating rods in the pinch roller group 2 and the traction roller group 5 work to preheat the inserted bag film 13. At the same time, the compensation roller 14 on the elastic compensation frame 11 elastically presses against the bag film 13 under the action of the compensation spring 12, so that the bag film 13 is kept in a tensioned state. S3. Intermittent feeding and continuous pulling: The transmission mechanism drives the pinch roller group 2 and the pulling roller group 5 to rotate synchronously and intermittently, realizing the intermittent feeding of the bag film 13. At the same time, the transmission mechanism drives the rotating shaft 10 to rotate at a constant speed, driving the conical transmission body 8 to rotate. The conical transmission body 8, through its arc-shaped transmission cone surface and the transmission frame 9, and then through the elastic connection mechanism, drives the reciprocating pulling frame 3 and the pulling roller group 5 on it to perform reciprocating linear motion, so that the bag film 13 is stretched at a fixed stroke when the pinch roller group 2 stops intermittently. S4. Stretch adjustment: The main controller 31 controls the linear transmission module 6 to drive the sliding adjustment frame 7 to slide linearly along the frame 1, changing the transmission connection position between the conical transmission body 8 and the transmission frame 9, thereby adjusting the single reciprocating stroke of the reciprocating traction frame 3 to achieve fixed length control of the single stretch length of the bag film 13. S5. High-temperature temporary shaping: During the stretching process, the electric heating rod in the guide roller and the electric heating table 15 on the elastic compensation frame 11 work together to control the temperature of the bag film 13 at 80°C, so that the molecular chains of the bag film 13 rearrange under stress and achieve temporary shaping of the film. S6. Cooling, shaping and unloading: The bag film 13, after being stretched and temporarily shaped, enters the shaping gap formed by two symmetrically arranged annular shaping belts 16. The transmission mechanism drives the linkage module to drive the two annular shaping belts 16 to rotate synchronously in opposite directions at a uniform speed, performing roll forming on the bag film 13. At the same time, the semiconductor cooling plate 17 set on the frame 1 works, transferring low temperature to the surface of the bag film 13 through the annular shaping belts 16, making it rapidly cool to 15°C, and finally outputting a bag film substrate with stable dimensions.

[0025] Specifically, the flexible packaging bag fixed-length pulling device of the present invention uses frame 1 as the basic carrier and is driven by a dual-head motor 19 as the core power source. When it works, the food-grade PE / PP composite bag film 13 is first arranged in a Z-shape and passed between the clamping roller group 2 and the pulling roller group 5 arranged in an array on the frame 1. The compensation roller 14 elastically presses against the bag film 13 between the two. In the transmission mechanism, one output shaft of the dual-head motor 19 drives the intermittent toothed gear 21 to rotate. Through the meshing with the intermittent gear 22, the clamping roller group 2 and the pulling roller group 5 are driven to rotate synchronously and intermittently via the third transmission belt, the first transmission belt, and the second transmission belt. The electric heating rod in the guide roller synchronously preheats the bag film 13 to 80°C, so that it is in a stretchable state. At the same time, the dual-head motor 19 drives the rotating shaft 10 to rotate at a uniform speed, which drives the conical transmission body 8 to rotate. The conical transmission body 8 is driven by the transmission frame 9 through the arc-shaped transmission cone surface. Then, through the elastic connection mechanism, the reciprocating pulling frame 3 is driven to make reciprocating linear motion along the frame 1 to realize the pulling and stretching of the bag film 13. Simultaneously, the position of the sliding adjustment frame 7 can be adjusted through the linear transmission module 6, changing the transmission connection point between the conical transmission body 8 and the transmission frame 9, thereby precisely adjusting the stroke of the reciprocating traction frame 3 to achieve fixed-length control of the stretching amount of the bag film 13. The compensation spring 12 on the elastic compensation frame 11 drives the compensation roller 14 to automatically compensate for the stretching and relaxation amount of the bag film 13 during the stretching process, ensuring that the bag film 13 is taut throughout the process. The electric heating table 15 and the electric heating rod work together to control the temperature at 80℃, causing the molecular chains of the bag film 13 to rearrange and achieve temporary shaping. The double-headed The other output shaft of motor 19 drives the linkage module through the fourth transmission belt, which drives the two symmetrical annular shaping belts 16 to rotate synchronously in opposite directions, forming a shaping gap. The bag film 13, which has completed temporary shaping, passes through the gap at a uniform speed. The annular shaping belts 16 roll it evenly. At the same time, the semiconductor cooling plate 17 on the frame 1 transfers a low temperature of 15°C to the surface of the bag film 13 through the annular shaping belts 16, so that the bag film 13 cools down quickly, allowing the rearranged molecular chains to be quickly fixed and formed, completing the cold locking shape to eliminate the shrinkage stress. The tensioning components in the transmission mechanism can automatically compensate for the slack of the transmission belt, ensuring the accuracy of each transmission link. The entire process realizes the continuous operation of multi-layer synchronous fixed-length material pulling, high-temperature temporary shaping and low-temperature cold-state locking of the bag film 13. Each process is precisely linked, and the final output bag film 13 substrate with regular size and stable shape is achieved.

[0026] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fixed-length material pulling device for flexible packaging bags, comprising a frame, characterized in that, Also includes: Multiple sets of pinch rollers are arrayed on a frame, and bag film is pinched on the multiple sets of pinch rollers; A reciprocating traction frame is slidably connected to a frame. A reciprocating spring is provided between the reciprocating traction frame and the frame. Multiple sets of traction rollers are connected to the reciprocating traction frame at positions parallel to the pinch roller sets. A linear drive module is fixedly mounted on a frame. A sliding adjustment frame is connected to the linear drive module. The sliding adjustment frame is slidably connected to the frame. A conical drive body is rotatably connected to the sliding adjustment frame. The transmission frame is connected to the conical transmission body and is provided with an elastic connection mechanism between it and the reciprocating traction frame; The rotating shaft is rotatably connected to the frame and is connected to the conical transmission body for transmission. An elastic compensation frame is slidably connected to a frame. A compensation spring is provided between the elastic compensation frame and the frame. A compensation roller connected to the bag film transmission is rotatably connected to the elastic compensation frame. An electric heating table is also fixedly installed on the elastic compensation frame. A linkage module is set on the frame. The linkage module is provided with two symmetrically arranged annular shaping belts. A shaping gap that cooperates with the bag film is provided between the two annular shaping belts. A semiconductor cooling plate is installed on the frame at a position corresponding to the inner side of the two annular shaping belts. The transmission mechanism, mounted on the frame, is used to drive the pinch roller group and the traction roller group to rotate synchronously and intermittently, as well as to drive the rotating shaft and the linkage module to rotate at a constant speed.

2. The flexible packaging bag fixed-length feeding device according to claim 1, characterized in that, The multiple sets of pinch rollers and multiple sets of traction rollers cooperate with each other. Each set of pinch rollers and traction rollers includes two symmetrically arranged guide rollers. Each of the two guide rollers is equipped with a first linkage gear, and the two first linkage gears mesh with each other. Each of the two guide rollers is fitted with a rubber sleeve, and a conveying gap that cooperates with the bag film is fixedly provided between the rubber sleeves. An electric heating rod is integrated inside the guide roller.

3. The flexible packaging bag fixed-length feeding device according to claim 1, characterized in that, The cross-section of the conical transmission body is an isosceles trapezoid. An arc-shaped transmission cone is fixedly provided on the conical transmission body. The arc-shaped transmission cone is connected to the transmission frame. A shaft hole that is slidably connected to the rotating shaft is opened at the axial position of the conical transmission body. The cross-sections of the shaft hole and the rotating shaft are both regular hexagons.

4. The flexible packaging bag fixed-length feeding device according to claim 1, characterized in that, The transmission mechanism includes a first transmission belt and a second transmission belt. Two adjacent pinch roller groups are connected by the first transmission belt, and two adjacent traction roller groups are connected by the second transmission belt. A double-headed motor is fixedly mounted on the frame. One end of the double-headed motor is fixedly connected to a rotating shaft, and the other end of the double-headed motor is connected to an intermittent toothed gear. The intermittent toothed gear meshes with an intermittent gear. The intermittent gear is rotatably connected to the frame through a connecting shaft. A tensioning element is provided on the frame. A third transmission belt is wound around a guide roller in one of the traction roller groups, a guide roller in one of the pinch roller groups, the connecting shaft, and the tensioning element.

5. A fixed-length feeding device for flexible packaging bags according to claim 4, characterized in that, The tensioning component includes a tensioning slider slidably connected to the frame, a tensioning spring mounted on the side of the tensioning slider, the other end of the tensioning spring being fixedly connected to the frame, and a tensioning pulley rotatably connected to the tensioning slider, the tensioning pulley being driven by a third transmission belt.

6. The flexible packaging bag fixed-length feeding device according to claim 1, characterized in that, The elastic connection mechanism includes a T-shaped limiting rod fixed on the transmission frame. The T-shaped limiting rod is slidably connected to the reciprocating traction frame. The axis of the T-shaped limiting rod is perpendicular to the rotation axis of the conical transmission body. A compression spring is sleeved on the T-shaped limiting rod at a position corresponding to the reciprocating traction frame and the transmission frame.

7. A fixed-length feeding device for flexible packaging bags according to claim 4, characterized in that, The linkage module includes two first transmission rollers and two second transmission rollers rotatably connected to the frame. A second linkage gear is installed on one of the first transmission rollers and one of the second transmission rollers. The two second linkage gears mesh with each other. A fourth transmission belt is driven to one of the output shafts of the dual-head motor. The fourth transmission belt is driven to one of the first transmission rollers.

8. The method of using a fixed-length feeding device for flexible packaging bags according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Inserting the bag film: The bag film made of plastic composite film is inserted through the multiple pinch roller groups and traction roller groups arranged in an array on the frame in a Z-shaped manner. S2. Heating and tensioning: Start the device to make the electric heating rods in the pinch roller group and the traction roller group work to preheat the inserted bag film. At the same time, the compensation roller on the elastic compensation frame elastically presses against the bag film under the action of the compensation spring to keep the bag film in a taut state. S3. Intermittent feeding and continuous pulling: The transmission mechanism drives the pinch roller group and the pulling roller group to rotate synchronously and intermittently, realizing the intermittent feeding of the bag film. At the same time, the transmission mechanism drives the rotating shaft to rotate at a constant speed, which drives the conical transmission body to rotate. The conical transmission body, through its arc-shaped transmission cone surface and the transmission frame, drives the reciprocating pulling frame and the pulling roller group on it to perform reciprocating linear motion through the elastic connection mechanism, so as to stretch the bag film at a fixed stroke when the pinch roller group stops intermittently. S4. Stretch adjustment: The main controller controls the linear transmission module to drive the sliding adjustment frame to slide linearly along the frame, changing the transmission connection position between the conical transmission body and the transmission frame, thereby adjusting the single reciprocating stroke of the reciprocating traction frame to achieve fixed length control of the single stretch length of the bag film. S5. High-temperature temporary shaping: During the stretching process, the electric heating rods in the guide rollers and the electric heating table on the elastic compensation frame work together to raise the temperature of the bag film, causing the molecular chains of the bag film to rearrange under stress, thereby achieving temporary shaping of the film. S6. Cooling, shaping and unloading: The bag film, after being stretched and temporarily shaped, enters the shaping gap formed by two symmetrically arranged annular shaping belts. The transmission mechanism drives the linkage module to drive the two annular shaping belts to rotate synchronously in opposite directions at a uniform speed, performing roll forming on the bag film. At the same time, the semiconductor cooling plate set on the frame works, transferring low temperature to the surface of the bag film through the annular shaping belts, so that it can be cooled quickly, and finally output bag film substrate with stable dimensions.

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