A device for applying a bag closure strip to a paper-plastic bag

Abstract

The application discloses a paper-plastic bag opening adhesive tape attaching device, which comprises a base frame, a bag opening positioning mechanism, an adhesive tape conveying mechanism, a hot-pressing sealing mechanism and a control module. The bag opening positioning mechanism is positioned by a vacuum chuck and a pneumatic side pressing plate. The adhesive tape conveying mechanism adopts a servo motor and a magnetic powder brake to realize dynamic tension control. The upper pressing plate of the hot-pressing sealing mechanism is internally provided with a micro flow channel, and a gear pump is used to circulate heat conduction oil to realize uniform temperature control. The control module is integrated with multiple actuators through a PROFINET bus. A paper-plastic bag opening adhesive tape attaching method is also disclosed, which comprises accurate positioning, tension control cutting, three-stage hot-pressing and infrared detection. The positioning accuracy of the device reaches 0.08 mm, the hot-sealing strength is increased by 25%, and the energy consumption is reduced by 37%.

Description

Technical Field

[0001] This utility model belongs to the field of packaging equipment technology, and specifically relates to a paper-plastic bag mouth sealing strip device. Background Technology

[0002] Currently, the sealing of paper-plastic bags mainly relies on manual operation for the labeling process, which has significant limitations. First, manual labeling is inefficient. Second, the labeling position is prone to significant deviations, easily resulting in appearance defects such as skewing and wrinkles, which are detrimental to subsequent sealing and transportation. In addition, the heat sealing method of traditional labeling machines does not have precise temperature control, frequently leading to insufficient seal strength and localized overheating that damages the bag, seriously affecting the product's sealing performance and appearance.

[0003] Current labeling devices generally suffer from problems such as unstable feeding, insufficient positioning accuracy, and uncontrollable heat-pressing parameters. For example, in basic structures using mechanical limiters, bag opening positioning can only be roughly adjusted by physical limit blocks, resulting in significant fluctuations in accuracy; the labeling material conveying relies on ordinary motors to control tension, which is prone to slippage, over-tightening, or slackness, leading to uneven labeling stress; the heat-sealing section generally uses single-stage constant-temperature heating, lacking a staged control mechanism, making it difficult to guarantee bonding strength and stability. These problems make existing equipment unable to meet the requirements of efficient, high-quality continuous production, becoming a major bottleneck restricting the automation improvement of paper-plastic bag packaging. Summary of the Invention

[0004] To address the aforementioned problems, this utility model aims to provide a highly efficient and energy-saving paper-plastic bag opening sealing device, which realizes automatic bag opening positioning, precise feeding, fixed-length cutting, and high-temperature hot-press sealing functions.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A paper-plastic bag opening sealing device includes a base frame, a bag opening positioning mechanism, a sealing conveying mechanism, a heat-sealing mechanism, and a control module.

[0007] The base frame includes a main frame and a mounting panel, with the mounting panel located on the top surface of the main frame;

[0008] The bag opening positioning vacuum pipeline mechanism includes a bracket, a vacuum suction cup, a pneumatic side pressure plate, and a linear slide rail. The vacuum suction cup is embedded in the through hole of the bracket. The vacuum suction cup is connected to the vacuum pipeline through a quick-change connector. The cylinder body of the pneumatic side pressure plate is connected to the slider of the linear slide rail through a flange seat bolt. The linear slide rail is fixed to both sides of the mounting panel by bolts.

[0009] The strip conveying mechanism includes a servo motor, a receiving and unloading reel, a magnetic powder brake, a deviation correction sensor, a conveyor belt, a hydraulic cylinder, and a column. The keyway of the output shaft of the servo motor is connected to the unloading reel via a flat key. Both ends of the unloading reel of the servo motor are mounted on a vertical support via bearings. The vertical support is fixed to the mounting panel by bolts. The magnetic powder brake is connected to the shaft end of the unloading reel via a sprocket coupling. The deviation correction sensor is located on two side plates of the conveyor belt, which are fixed to the mounting panel. The side plates are equipped with a drive roller and a driven roller. The drive roller is connected to a drive motor via a sprocket. The cylinder flange of the hydraulic cylinder is connected to the column, which is welded to the mounting panel. The piston rod of the hydraulic cylinder is equipped with a pressure block, and the pressure block is equipped with an upper blade.

[0010] The hot-press sealing module includes a servo electric cylinder, a gantry beam, a lower support, and a gear pump. The cylinder body of the servo electric cylinder is fixed to the gantry beam via a flange. The gantry beam is welded to the main frame. The piston rod of the servo electric cylinder is connected to an upper pressure plate. The lower support is fixed to the mounting panel via bolts. The upper pressure plate has a microchannel inside. The inlet and outlet of the microchannel are connected to the gear pump oil pipe via quick-connect couplings. The gear pump is fixed to the bottom of the main frame via a bracket. The gear pump oil pipe is connected to the inlet and outlet of the upper pressure plate via quick-connect couplings.

[0011] The control module includes a PLC controller, an electrical control box, a servo driver, a solenoid valve, and a vacuum generator. The PLC controller is installed in the electrical control box and is connected to the servo driver via a PROFINET bus. The PU tube at the output port of the solenoid valve is connected to the cylinder body and the vacuum generator.

[0012] As an improvement of this utility model, the lower support platform includes a ceramic fiber plate and a copper plate. The ceramic fiber plate is fixed to the mounting panel by countersunk bolts, and the copper plate is bonded to the upper surface of the ceramic fiber plate with thermally conductive adhesive. A grid groove with a depth of 0.3mm is formed on the surface of the copper plate.

[0013] As an improvement of this utility model, the main frame is welded into a rectangle by carbon steel square tubes. The main frame is fixed to the aluminum alloy mounting panel by M8 hexagonal bolts. Shock-absorbing pads are connected to the four corners of the bottom of the main frame. The threaded sleeve in the center of the shock-absorbing pad is screwed into the nuts welded to the four corners of the bottom of the main frame.

[0014] As an improvement of this utility model, the bracket is vertically fixed to the front side of the mounting panel by four M6 bolts, and eight Φ15.5mm through holes are opened in the horizontal arm of the bracket.

[0015] As an improvement of this utility model, a disc spring is provided at the connection between the upper pressure plate and the piston rod. The spring has an outer diameter of Φ25mm and a preload of 0.5mm.

[0016] As an improvement of this utility model, the grid groove is connected to the vacuum pipeline, and a vacuum pump is connected to the end of the vacuum pipeline.

[0017] The beneficial effects of this utility model are as follows:

[0018] (1) The paper-plastic bag sealing strip device provided by this utility model adopts centralized control by a PLC controller. The operating system communicates at high speed through the PROFINET industrial Ethernet bus, which not only realizes closed-loop control of the machine, but also facilitates docking with upstream packaging lines and downstream conveying systems, and has excellent scalability and system integration capabilities. This control method reduces human intervention, significantly improves production efficiency and stability, and is particularly suitable for continuous operation in medium and large-scale production workshops.

[0019] (2) The bag opening positioning mechanism combines a vacuum suction cup adsorption and a pneumatic side pressure plate clamping mechanism. The suction cup is connected to the vacuum generator through a quick-change connector, ensuring stable and reliable adsorption force. The side pressure plate advances smoothly along the linear slide rail, and with the cylinder buffer structure, it can accurately fit bag openings of different sizes and thicknesses. The measured clamping displacement error is less than 0.1mm. This effectively avoids problems such as bag opening lifting and offset in traditional mechanical limiting methods.

[0020] (3) The strip application method provided by this utility model adopts a three-stage hot-press control technology. The upper pressure plate integrates a microchannel structure, which allows the heat transfer oil to circulate inside the pressure plate. This can heat the pressure plate to the set temperature in a very short time and maintain temperature uniformity. The temperature and pressure of each stage (preheating, melting, and shaping) are set independently to ensure that the seal is flat, free from coking and voids, and the seal peel strength is increased by more than 20%, effectively meeting the requirements for high sealing performance.

[0021] (4) Compared with traditional electric heating wire or plate heating structures, this utility model adopts a microchannel structure with oil circulation heating, which has fast temperature control response and low energy consumption of the upper pressure plate. At the same time, the structure is easy to disassemble and clean, which is conducive to maintenance during long-term operation. In addition, the electrical control system has fault diagnosis and self-protection functions, which can reduce unexpected downtime. Attached Figure Description

[0022] Figure 1 A schematic diagram of the device for attaching a paper-plastic bag opening.

[0023] List of reference numerals in the attached diagram:

[0024] 1. Main frame; 2. Mounting panel; 6. Shock-absorbing feet; 7. Threaded sleeve; 31. Bracket; 32. Pneumatic side pressure plate; 33. Cylinder body; 34. Flange seat; 35. Slider; 36. Linear guide rail; 41. Servo motor; 42. Reel and unload shaft; 43. Vertical support; 44. Conveyor belt; 45. Hydraulic cylinder; 46. Column; 47. Pressure block; 48. Upper blade; 51. Servo electric cylinder; 52. Gantry beam; 53. Piston rod; 54. Upper pressure plate; 55. Gear pump; 56. Vacuum pump. Detailed Implementation

[0025] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0026] Example 1

[0027] A paper-plastic bag opening sealing device includes a base frame, a bag opening positioning mechanism, a sealing conveying mechanism, a heat-sealing mechanism, and a control module.

[0028] The base frame includes a main frame 1 and a mounting panel 2, with the mounting panel 2 located on the top surface of the main frame 1.

[0029] The bag opening positioning vacuum pipeline mechanism includes a bracket 31, a vacuum suction cup, a pneumatic side pressure plate 32, and a linear slide rail 36. The vacuum suction cup is embedded in the through hole of the bracket 31. The vacuum suction cup is connected to a vacuum pipeline through a quick-connect coupling. The cylinder body 33 of the pneumatic side pressure plate 32 is bolted to the slider 35 of the linear slide rail 36 through a flange seat 34. The linear slide rail 36 is fixed to both sides of the mounting panel 2 by bolts.

[0030] The strip conveying mechanism includes a servo motor 41, a receiving and unloading shaft 42, a magnetic powder brake, a correction sensor, a conveyor belt 44, a hydraulic cylinder 45, and a column 46. The output shaft of the servo motor 41 is connected to the unloading shaft 42 via a keyway and a flat key. Both ends of the unloading shaft of the servo motor 41 are mounted on a vertical support 43 via bearings. The vertical support 43 is fixed to the mounting panel 2 by bolts. The magnetic powder brake is connected to the shaft end of the unloading shaft 42 via a swivel coupling. The correction sensor is located on two side plates of the conveyor belt 44. The side plates of the conveyor belt 44 are fixed to the mounting panel 2. The side plates are equipped with a drive roller and a driven roller. The drive roller is connected to a drive motor via a sprocket. The cylinder flange of the hydraulic cylinder 45 is connected to the column 46. The column 46 is welded to the mounting panel 2. The piston rod 53 of the hydraulic cylinder 45 is provided with a pressure block 47. The pressure block 47 is provided with an upper blade 48.

[0031] The hot-press sealing module includes a servo electric cylinder 51, a gantry beam 52, a lower support, and a gear pump 55. The cylinder body of the servo electric cylinder 51 is fixed to the gantry beam 52 by a flange. The gantry beam 52 is welded to the main frame 1. The piston rod 53 of the servo electric cylinder 51 is connected to an upper pressure plate 54 at its end. The lower support is fixed to the mounting panel 2 by bolts. The upper pressure plate 54 has a microchannel inside. The inlet and outlet of the microchannel are connected to the oil pipe of the gear pump 55 through quick-change connectors. The gear pump 55 is fixed to the bottom of the main frame 1 by a bracket 31. The oil pipe of the gear pump 55 is connected to the inlet and outlet of the upper pressure plate 54 through quick-change connectors.

[0032] The control module includes a PLC controller, an electrical control box, a servo driver, a solenoid valve, and a vacuum generator. The PLC controller is installed in the electrical control box and is connected to the servo driver via a PROFINET bus. The PU tube at the output port of the solenoid valve is connected to the cylinder body 33 and the vacuum generator.

[0033] The lower support platform of this utility model includes a ceramic fiber plate and a copper plate. The ceramic fiber plate is fixed to the mounting panel 2 by countersunk bolts, and the copper plate is bonded to the upper surface of the ceramic fiber plate with thermally conductive adhesive. The surface of the copper plate has a grid groove with a depth of 0.3mm.

[0034] The main frame 1 of this utility model is welded from carbon steel square tubes into a rectangle. The main frame 1 is fixed with aluminum alloy mounting panel 2 by M8 hexagon socket bolts. Shock-absorbing pads 6 are connected to the four corners of the bottom of the main frame 1. The threaded sleeve 7 in the center of the shock-absorbing pad 6 is screwed into the nuts welded to the four corners of the bottom of the main frame 1.

[0035] The bracket 31 of this utility model is vertically fixed to the front side of the mounting panel 2 by four M6 bolts, and eight Φ15.5mm through holes are opened in the horizontal arm of the bracket 31.

[0036] The connection between the upper pressure plate 54 and the piston rod 53 of this utility model is provided with a disc spring with an outer diameter of Φ25mm and a preload of 0.5mm.

[0037] The grid groove described in this invention is connected to a vacuum pipeline, and a vacuum pump 56 is connected to the end of the vacuum pipeline.

[0038] Example 2

[0039] A paper-plastic bag opening sealing strip device, adopting the structure of Embodiment 1, uses a Siemens S7-1200 series PLC controller for the control system, a -0.6MPa negative pressure generator for the vacuum system, a custom-designed microfluidic copper upper pressure plate for the hot pressing module, and a gear pump for temperature-controlled oil supply. The device sets the bag opening sealing strip length (L=120mm) and strip width (w=30mm), and includes the following sealing steps:

[0040] S1. A manipulator places the opening of a paper-plastic bag on the horizontal plane of the support, a PLC controller triggers a vacuum generator to make the vacuum suction chuck generate -0.6MPa negative pressure, and at the same time a pneumatic side pressing plate moves along the linear slide rail to the side wall of the bag opening;

[0041] S2. Feeding: A servo motor drives an unwinding shaft to convey the adhesive strip, a deviation correction sensor adjusts the deviation to ≤±0.5mm, and a magnetic powder brake dynamically adjusts the tension according to the formula ,

[0042]

[0043] wherein the unit is N, v is the linear speed in m / min, and w is the width of the adhesive strip in mm;

[0044] S3. Cutting: When the adhesive strip reaches the set length L, a hydraulic cylinder drives an upper blade to press down to the lower bearing platform,

[0045]

[0046] wherein, is the width of the bag opening;

[0047] S4. Hot pressing: An electric cylinder drives an upper pressing plate to press down:

[0048] S41. Preheating at 160°C, with a pressure of 0.5MPa and pressure holding for 0.8s;

[0049] S42. Melting at 185°C, the pressure rises to 1.2MPa, and the pressure is held for 1.5s;

[0050] S43. Shaping at 150°C, the pressure drops to 0.8MPa, and the pressure is held for 2.0s

[0051] S5. Detection: An infrared thermal imager scans the sealing area, if the minimum temperature and the temperature standard deviation , it is determined to be qualified.

[0052] According to measurement, the peeling strength of the seal is 28.4 N / 15mm, the temperature difference in the sealing area is ≤3.2°C, the offset of the adhesive strip is ±0.2mm, and the qualification rate is 98.7%.

[0053] Conventional adhesive strip equipment adopts constant-temperature heat sealing, generally the hot pressing temperature is 170~190°C, the sealing time is 3-5s, and most offsets are above ±1mm. In comparison, the present utility model controls the temperature difference within 3°C and the offset of the adhesive strip within 0.2mm through micro-channel temperature control, three-stage hot pressing and a servo positioning system, which is obviously better than the average industry level.

[0054] It should be noted that the accompanying drawings merely illustrate the technical concept of this utility model and should not be used to limit the scope of protection of this utility model. For those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and all such improvements and modifications fall within the scope of protection of the claims of this utility model.

Claims

1. A paper-plastic bag opening labeling device, comprising a base frame, a bag opening positioning mechanism, a labeling conveying mechanism, a heat-sealing mechanism, and a control module, characterized in that: The base frame includes a main frame and a mounting panel, with the mounting panel located on the top surface of the main frame; The bag opening positioning mechanism includes a bracket, a vacuum suction cup, a pneumatic side pressure plate, and a linear slide rail. The vacuum suction cup is embedded in the through hole of the bracket and connected to the vacuum pipeline through a quick-change connector. The cylinder body is connected to the slider through a flange seat. The slider is installed on the linear slide rail, and the linear slide rail is fixed on both sides of the mounting panel. The labeling conveying mechanism includes a servo motor, an unwinding shaft, a magnetic powder brake, a deviation correction sensor, a conveyor belt, a hydraulic cylinder, and a column. The servo motor is connected to the unwinding shaft via a key. The unwinding shaft is mounted on a vertical support via bearings. The vertical support is fixed to the mounting panel. The magnetic powder brake is connected to the end of the unwinding shaft. The conveyor belt is located on the mounting panel and is connected to the drive motor via rollers. The hydraulic cylinder is connected to the column via a flange. The column is welded to the mounting panel. The piston rod of the hydraulic cylinder is equipped with a pressure block, and the pressure block is equipped with an upper blade. The hot-press sealing mechanism includes a servo electric cylinder, a gantry beam, a lower support, and a gear pump. The servo electric cylinder is fixed to the beam, the piston rod is connected to the upper pressure plate, the lower support is fixed to the mounting panel, the upper pressure plate has a microchannel inside, the quick-connect coupling is connected to the gear pump oil pipe, and the gear pump is fixed to the main frame by a bracket. The control module includes a PLC controller, an electrical control box, a servo driver, a solenoid valve, and a vacuum generator. The PLC controller is connected to the driver via a bus, and the output pipe of the solenoid valve is connected to the cylinder and the vacuum generator.

2. The device of claim 1, wherein: The lower support includes a ceramic fiber plate and a copper plate. The ceramic fiber plate is fixed to the mounting panel by countersunk bolts, and the copper plate is bonded to the upper surface of the ceramic fiber plate with thermally conductive adhesive. The surface of the copper plate has a grid groove with a depth of 0.3mm.

3. The device of claim 1, wherein: The main frame is welded from carbon steel square tubes into a rectangle. The main frame is fixed with aluminum alloy mounting panels by M8 hexagonal bolts. Shock-absorbing pads are connected to the four corners of the bottom of the main frame. The threaded sleeves in the center of the shock-absorbing pads are screwed into the nuts welded to the four corners of the bottom of the main frame.

4. The device of claim 1, wherein: The bracket is vertically fixed to the front side of the mounting panel by four M6 bolts, and eight Φ15.5mm through holes are opened in the horizontal arm of the bracket.

5. The device of claim 1, wherein: A disc spring is provided at the connection between the upper pressure plate and the piston rod. The spring has an outer diameter of Φ25mm and a preload of 0.5mm.

6. The device of claim 2, wherein: The grid groove is connected to the vacuum pipeline, and a vacuum pump is connected to the end of the vacuum pipeline.

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