An apparatus for producing a packaging bag and a packaging bag

Abstract

The application relates to the technical field of packaging bag production mechanical equipment, and discloses a device for producing packaging bags and the packaging bags, a paper unwinding part, a die cutting part, a static glue coating part, a dynamic glue coating part and a forming part. The dynamic glue coating part comprises a rack, a roller abutting against paper, a reciprocating screw rod driven by the roller, a sliding block threadedly connected with the reciprocating screw rod and a glue gun fixed to the sliding block; a transmission mechanism is arranged between the roller and the reciprocating screw rod, the transmission mechanism comprises an output shaft, a transmission rod, a linkage shaft and a two-stage bevel gear set, synchronous rotation of the roller and the reciprocating screw rod is realized, the paper movement drives the roller to rotate, and then drives the reciprocating screw rod to rotate in one direction, so that the sliding block reciprocatingly moves. The application has the beneficial effects that the paper itself movement is used as power, the transverse movement speed of the glue gun automatically follows the paper speed change, an independent motor and a complex electric control system are not needed, the structure is simple, the cost is low, and the glue coating position is accurate.

Description

Technical Field

[0001] This invention relates to the technical field of packaging bag production machinery and equipment, specifically to an apparatus for producing packaging bags and packaging bags. Background Technology

[0002] Paper packaging bags are widely used in food, daily chemicals, and logistics industries due to their advantages such as being environmentally friendly, recyclable, and biodegradable. A typical packaging bag manufacturing process includes the following steps: unwinding the base paper → punching and cutting → creasing and folding → gluing → sealing the bottom → finished product collection. Among these, the gluing process is the key step that determines the bonding quality and sealing performance of the packaging bag.

[0003] In the adhesive coating process of packaging bags, common types of adhesive coating include: bottom coating, sealing coating, and easy-tear strip coating. Among them, the adhesive coating of the easy-tear strip area has higher requirements: the glue needs to be applied to a narrow strip area, the application position needs to be precisely aligned with the tear line or easy-tear strip boundary, and the amount of glue needs to be uniform to ensure a strong seal while allowing consumers to easily tear it open.

[0004] Existing packaging bag gluing devices mostly use independent motors to drive the gluing gun and photoelectric sensors to detect the position of the packaging bag. A PLC or microcontroller coordinates the lateral movement of the gluing gun and the vertical transport of the packaging bag. When the packaging bag transport speed changes, such as during production line speed adjustment or start-up / stop, manual or automatic adjustment of control parameters is required. Otherwise, the lateral movement speed of the gluing gun and the paper transport speed cannot match, resulting in stretching or compression of the gluing trajectory and compromised gluing quality. Therefore, a new technical solution is needed to address these technical problems. Summary of the Invention

[0005] This application proposes an apparatus for producing packaging bags and a packaging bag. The apparatus utilizes the movement of the paper itself to drive a roller. The roller, through a transmission mechanism, drives a reciprocating screw to rotate synchronously. The reciprocating screw drives a slider to move back and forth, and a glue gun applies glue as the slider moves. Since the lateral movement speed of the glue gun is entirely determined by the vertical movement speed of the paper, the two automatically maintain synchronization without any electronic control adjustment. When the paper speed changes, the glue gun speed changes proportionally, and the length and position of the glue application trajectory remain stable. This fundamentally solves the problem of stretching or compression of the glue application trajectory due to speed changes in existing technologies, thereby improving the glue application quality.

[0006] Therefore, the first aspect of this application provides an apparatus for producing packaging bags, which includes an unwinding section for releasing paper, a die-cutting section for opening windows in the paper, a static gluing section for applying glue to the opening of the packaging bag, a dynamic gluing section for applying glue to the tear strips of the paper, and a forming section for folding the paper. The dynamic gluing section includes a frame placed on the working surface for paper to pass through, rollers rotatably connected to the frame and in contact with the paper, a reciprocating screw driven by the rollers and rotatably connected to the frame, a slider threadedly connected to the reciprocating screw, and a glue gun fixedly connected to the slider for spraying glue onto the paper. The reciprocating screw rotates in one direction to drive the slider to move back and forth along the axis of the reciprocating screw. The slider is slidably connected to the frame. A transmission mechanism is provided between the reciprocating screw and the rollers to make the reciprocating screw and the rollers rotate synchronously.

[0007] By adopting the above technical solution: the paper's own movement drives the roller, which in turn drives the reciprocating screw to rotate synchronously through a transmission mechanism. The reciprocating screw drives the slider to move back and forth, and the glue gun moves with the slider to apply glue. Since the horizontal movement speed of the glue gun is completely determined by the vertical movement speed of the paper, the two automatically maintain synchronization without any electronic control adjustment. When the paper speed changes, the glue gun speed changes proportionally, and the length and position of the glue application trajectory remain stable. This fundamentally solves the problem of stretching or compression of the glue application trajectory caused by speed changes in existing technologies, thereby achieving the goal of improving the glue application quality.

[0008] Preferably, the transmission mechanism includes an output shaft that is located at the roller and rotated by the roller, and a transmission rod that is located between the output shaft and the reciprocating screw. The transmission rod is fixedly connected to the frame. Transmission cavities are provided at both ends of the transmission rod near the output shaft and the reciprocating screw. A linkage channel is provided between the two transmission cavities. A linkage shaft is rotatably arranged in the linkage channel. A first bevel gear set is provided between the linkage shaft and the output shaft to transmit the rotational power of the output shaft to the linkage shaft. A second bevel gear set is provided between the linkage shaft and the reciprocating screw to transmit the rotational power to the reciprocating screw.

[0009] By adopting the above technical solution, the vertical transmission or spatially interlaced transmission between the roller output shaft and the reciprocating screw input shaft is realized through a two-stage bevel gear set and a transmission rod with an internal linkage shaft. This allows the roller and reciprocating screw to be flexibly arranged according to the machine frame space, saving installation space. The enclosed cavity inside the transmission rod protects and seals the bevel gear set, preventing dust contamination and extending its service life. The two-stage bevel gear transmission is smooth and low-noise, and can accurately transmit rotational power, ensuring the synchronization accuracy between the roller and the reciprocating screw.

[0010] Preferably, the first bevel gear set includes a first bevel gear fixedly connected to the output shaft and a second bevel gear fixedly connected to the linkage shaft, with the first bevel gear meshing with the second bevel gear; the second bevel gear set includes a third bevel gear fixedly connected to the linkage shaft and a fourth bevel gear fixedly connected to the reciprocating lead screw, with the third bevel gear meshing with the fourth bevel gear.

[0011] By adopting the above technical solution: using standard bevel gear meshing transmission, the structure is compact and the transmission efficiency is high; by selecting bevel gear combinations with different numbers of teeth, the total transmission ratio can be easily adjusted, thereby adjusting the ratio of the horizontal movement speed of the glue gun to the vertical movement speed of the paper according to the paper speed and the required glue application interval, adapting to the production needs of packaging bags of different specifications. The bevel gear meshing has a self-locking characteristic to prevent reverse transmission and ensure the stability of the glue gun position during the glue application process.

[0012] Preferably, the transmission rod is provided with a mounting bracket for mounting the roller at one end near the roller. The mounting bracket includes a mounting strip fixedly connected to the side wall of the transmission rod and mounting plates disposed on both sides of the roller. The output shaft of the roller is rotatably connected to both mounting plates.

[0013] By adopting the above technical solution: the mounting frame provides a stable support for the roller, both ends of the roller output shaft are supported, the force is even, the rotation is smooth and reduces shaking and swaying, ensuring stable contact between the roller and the paper, the mounting frame is fixedly connected to the transmission rod, the overall rigidity is good, and it is easy to disassemble and maintain the whole.

[0014] Preferably, the dynamic coating section further includes a pressure roller for applying pressure to the paper to increase the friction between the roller and the paper. The pressure roller is rotatably connected to the frame and is arranged opposite to the roller. The paper passes through the middle of the roller and the pressure roller.

[0015] By adopting the above technical solution, the pressure roller applies positive pressure to the paper, making the paper and the roller fit tightly together, significantly increasing the friction between the roller and the paper, effectively preventing the roller from slipping on the paper surface, ensuring that the roller is reliably driven by the paper, thereby ensuring that the rotation speed of the reciprocating screw is strictly synchronized with the paper speed, and improving the glue application position accuracy.

[0016] Preferably, an elastic mounting device for flexibly pressing the paper is provided between the pressing roller and the frame. The elastic mounting device includes a mounting rod fixedly connected to the frame, a mounting block slidably connected to the mounting rod, and an elastic element sleeved on the outside of the mounting rod. The two ends of the pressing roller are rotatably connected to the two mounting blocks respectively, and the two ends of the elastic element are fixedly connected to the frame and the mounting blocks respectively. The elastic element is used to dynamically adjust the gap between the pressing roller and the roller.

[0017] By adopting the above technical solution, the flexible mounting device achieves flexible clamping of the clamping roller. When the paper thickness changes or encounters joints or folds, the clamping roller can automatically retract, compressing the elastic element to buffer the impact and prevent paper jamming or tearing. After the paper passes through, the elastic element resets, maintaining a constant clamping force. This structure adapts to fluctuations in paper thickness while avoiding paper damage or equipment jamming caused by rigid clamping, thus improving the stability of the production line and the paper throughput.

[0018] Preferably, the glue gun is equipped with a solenoid valve for controlling the glue supply. The solenoid valve is fixedly connected to the slider. The solenoid valve is equipped with a control device for controlling the unidirectional spraying of the glue gun. The control device includes a first contact switch located at one end of the reciprocating screw near the transmission mechanism and a second contact switch located at the other end of the reciprocating screw. When the slider slides, it is electrically connected to both the first and second contact switches. When the slider contacts the first contact switch, the solenoid valve controls the glue gun to open. When the slider abuts against the second contact switch, the solenoid valve controls the glue gun to close.

[0019] By adopting the above technical solution: the solenoid valve is controlled by a touch switch, so that the glue gun sprays only in one direction of the slider movement and automatically shuts off during the return stroke; this solves the contradiction between the continuous reciprocating motion of the reciprocating screw and the need for unidirectional glue application by the glue gun, and avoids glue contamination of parts other than the tear strip of the packaging bag during the return stroke. The touch switch is directly installed at both ends of the slider stroke, so the control signal has no delay and the glue application start and end positions are precisely controllable.

[0020] Preferably, the frame is provided with a slide groove for allowing the slider to slide, the slider and the reciprocating lead screw are both located in the slide groove, and the first touch switch and the second touch switch are respectively located at both ends of the slide groove.

[0021] By adopting the above technical solution: the slide provides precise linear guidance for the slider, preventing the slider from deflecting or shaking during movement, ensuring the straightness of the glue gun's glue application trajectory; the slide encloses the reciprocating screw and slider, providing protection and preventing dust and glue splashes from contaminating the transmission components; the touch switch is installed at both ends of the slide, with a fixed position, and its triggering relationship with the slider is stable and reliable.

[0022] A second aspect of this application provides a packaging bag produced by the aforementioned apparatus for producing packaging bags. The packaging bag includes a bag body, a flap folded down on the bag body, a tear line on the flap folded down, and an easy-tear strip in the area of ​​the tear line. The easy-tear strip area has a strip-shaped adhesive layer applied by a dynamic adhesive application portion.

[0023] By adopting the above technical solution: the packaging bags produced using the above device have a uniform and precise adhesive layer coating in the easy-tear strip area, ensuring that the folded flap is firmly bonded to the bag body when sealing, and that consumers can easily separate the easy-tear strip when tearing it; since the paper speed and glue gun speed are automatically synchronized during the glue application process, the length and width of the adhesive layer remain consistent even when the production line speed is adjusted, resulting in stable product quality.

[0024] Preferably, the strip-shaped adhesive layer is a non-drying adhesive layer, and the surface of the strip-shaped adhesive layer has periodic fine stripes formed by the reciprocating screw motion.

[0025] By adopting the above technical solution: the periodic fine stripes on the surface of the strip adhesive layer are caused by the pitch of the helical groove of the reciprocating screw. The fine stripes increase the surface area of ​​the adhesive layer, which is beneficial to improving the initial adhesion, and does not affect the peeling force when tearing the easy-tear strip.

[0026] The working principle and beneficial effects of this application are as follows: 1. This application utilizes the paper's own motion to drive the rollers. Through a bevel gear set, transmission rod, and reciprocating screw, the horizontal movement speed of the glue gun and the vertical movement speed of the paper are always kept in a fixed proportional relationship. No sensors, controllers, or servo motors are required. When the production line speed is adjusted or started / stopped, the glue gun speed automatically changes synchronously with the paper speed. The length, width, and position of the glue application trajectory remain constant. This fundamentally solves the problem of glue application trajectory stretching or compression caused by speed changes in the prior art, and significantly improves the stability and consistency of glue application quality.

[0027] 2. This application replaces the independent servo motor, encoder, PLC controller, and complex control algorithm in existing technologies with purely mechanical transmission components such as rollers, reciprocating lead screws, and bevel gear sets. Simultaneously, it uses touch switches to directly control the solenoid valve to achieve unidirectional glue application, eliminating the need for programming and parameter adjustment. The entire device has a compact structure, fewer parts, and a low failure rate, significantly reducing equipment manufacturing costs and maintenance difficulty, making it suitable for large-scale application on packaging bag production lines.

[0028] 3. This application sets a first touch switch and a second touch switch at both ends of the reciprocating screw, and uses a solenoid valve to control the opening and closing of the glue gun, so that the glue gun sprays only in one direction of the slider's movement (the glue application stroke), and automatically shuts off during the return stroke. This design perfectly solves the process contradiction between the continuous reciprocating motion of the reciprocating screw and the need for unidirectional glue application in the easy-tear strip area. It effectively prevents glue from contaminating the opening of the packaging bag and the area outside the easy-tear strip boundary during the return stroke, ensuring clear glue application boundaries and uniform glue amount, thereby simultaneously meeting the dual needs of strong sealing and easy tearing by consumers. Attached Figure Description

[0029] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] Figure 1 This is a schematic diagram of the structure of an apparatus for producing packaging bags according to this application; Figure 2 This is a schematic diagram of the structure of the dynamically coated part in this application; Figure 3 This is a schematic diagram of the transmission mechanism of this application; Figure 4 This is a schematic diagram of the flexible installation device of this application; Figure 5 This is a schematic diagram of the control device of this application; Figure 6 This is a schematic diagram of the structure of the packaging bag in this application; Figure 7 This is a structural schematic diagram of the packaging bag from another perspective.

[0031] The technical features in the attached drawings are labeled as follows: 1. Unwinding section; 2. Die-cutting section; 3. Static gluing section; 4. Dynamic gluing section; 41. Frame; 411. Slide groove; 42. Roller; 43. Reciprocating screw; 44. Slider; 45. Glue gun; 5. Forming section; 6. Transmission mechanism; 61. Output shaft; 62. Transmission rod; 621. Transmission cavity; 622. Linkage channel; 63. Linkage shaft; 7. First bevel gear set; 71. First bevel gear; 72. Second bevel gear; 8. Second bevel gear set; 81. Third bevel gear; 82. 9. Fourth bevel gear; 91. Mounting bracket; 92. Mounting strip; 10. Mounting plate; 20. Pressure roller; 20. Elastic mounting device; 201. Mounting rod; 202. Mounting block; 203. Elastic element; 30. Solenoid valve; 401. First touch switch; 402. Second touch switch; 50. Bag body; 501. Downward folding tongue; 5011. Easy-tear tooth; 5012. Relief groove; 502. Destruction line; 503. Strip adhesive layer; 504. Sealing strip; 505. Lifting handle; 60. Paper. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] like Figures 1-2 As shown, the first aspect of this embodiment provides an apparatus for producing packaging bags, including an unwinding section 1 for releasing the paper 60, a die-cutting section 2 for opening windows in the paper 60, a static gluing section 3 for applying glue to the bag opening, a dynamic gluing section 4 for applying glue to the tear strips of the paper 60, and a forming section 5 for folding the paper 60.

[0034] like Figure 1As shown, the unwinding section 1 includes an air shaft and a tension adjusting roller for releasing the paper 60. The die-cutting section 2 includes a die-cutting roller and a bottom roller for punching out the easy-tear strip outline and the tear line 502 on the paper 60. The die-cutting section 2 is also used to die-cut the lower folding tongue 501 of the bag body 50 into a specific shape. The static gluing section 3 includes a glue applicator that is fixedly installed for applying glue to the bag opening area of ​​the packaging bag. The forming section 5 includes a folding plate, a bottom gluing mechanism, and a conveyor belt for folding the paper 60 into a bag tube and gluing the bottom to form the bag.

[0035] like Figures 1-2 As shown, the dynamic gluing section 4 includes a frame 41 placed on the working surface for the paper 60 to pass through, a roller 42 rotatably mounted on the frame 41, a reciprocating screw 43 rotatably connected to the frame 41, a slider 44 threadedly connected to the reciprocating screw 43, and a glue gun 45 fixedly connected to the slider 44 for spraying glue onto the paper 60. A transmission mechanism 6 is provided between the roller 42 and the reciprocating screw 43 to make them rotate synchronously. The surface of the roller 42 abuts against the paper 60 sliding forward. In this embodiment, the surface of the roller 42 is covered with an elastic friction layer to increase the friction between the paper 60 and the roller 42. The surface of the reciprocating screw 43 has a screw with opposite rotation direction. The first and second spiral grooves are smoothly transitioned at both ends. The transition curve between the first and second spiral grooves is a modified sine curve. Its acceleration is continuous and the maximum acceleration value is less than a preset threshold, realizing continuous reciprocating glue application without impact or interruption. The starting and ending points of glue application are accurately positioned. The frame 41 is provided with a slide groove 411. The reciprocating screw 43 and the slider 44 are both placed in the slide groove 411. The reciprocating screw 43 is rotatably connected to the slide groove 411, and the slider 44 is slidably connected to the frame 41. The nozzle of the glue gun 45 is aligned with the tear strip area of ​​the paper 60. The glue supply line of the glue gun 45 is provided with a solenoid valve 30, which is connected to a control device.

[0036] In this embodiment, the dynamic glue application section 4 relies on a pure mechanical transmission chain consisting of roller 42, transmission mechanism 6, reciprocating screw 43, and slider 44 without an external power source. The ratio of the lateral movement speed of the glue gun 45 to the vertical movement speed of the paper 60 is determined only by the diameter of the roller 42, the speed ratio of the transmission mechanism 6, and the lead of the reciprocating screw 43, without relying on any electronic control adjustment, sensor feedback, or control algorithm. When the production line speeds up or stops, the speed of the paper 60 changes, and the speed of the glue gun 45 automatically changes proportionally, keeping the relative position of the glue application trajectory on the paper 60 unchanged. No PLC, servo motor, encoder, or other components are required, completely eliminating electronic control delay and parameter adjustment.

[0037] like Figures 2-3As shown, the transmission mechanism 6 includes an output shaft 61 fixedly connected to the roller 42 and a transmission rod 62 fixedly connected to the frame 41. Both ends of the transmission rod 62 are provided with transmission cavities 621, and a linkage channel 622 is provided between the two transmission cavities 621. A linkage shaft 63 is rotatably arranged in the linkage channel 622. A first bevel gear set 7 is provided between the output shaft 61 and the linkage shaft 63, and a second bevel gear set 8 is provided between the linkage shaft 63 and the reciprocating lead screw 43. The first bevel gear set 7 and the second bevel gear set 8 are respectively located in the two transmission cavities 621.

[0038] like Figures 2-3 As shown, the first bevel gear set 7 includes a first bevel gear 71 fixedly connected to the output shaft 61 and a second bevel gear 72 fixedly connected to the linkage shaft 63. The first bevel gear 71 and the second bevel gear 72 mesh. The second bevel gear set 8 includes a third bevel gear 81 fixedly connected to the other end of the linkage shaft 63 and a fourth bevel gear 82 fixedly connected to the input shaft of the reciprocating lead screw 43. The third bevel gear 81 and the fourth bevel gear 82 mesh.

[0039] like Figures 2-3 As shown, the transmission rod 62 is provided with a mounting bracket 9 for mounting the roller 42 at one end near the roller 42. The mounting bracket 9 includes a mounting strip 91 fixedly connected to the side wall of the transmission rod 62 and mounting plates 92 disposed on both sides of the roller 42. Both mounting plates 92 are fixedly connected to the mounting strip 91. The output shaft 61 is rotatably connected to the two mounting plates 92 through high-precision bearings.

[0040] like Figures 3-4 As shown, the dynamic gluing part 4 also includes a pressure roller 10 disposed opposite to the roller 42. The paper 60 passes between the pressure roller 10 and the roller 42. An elastic mounting device 20 for dynamically adjusting the gap between the pressure roller 10 and the roller 42 is provided between the pressure roller 10 and the frame 41. The elastic mounting device 20 includes a mounting rod 201 fixed to the frame 41, a mounting block 202 slidably connected to the mounting rod 201, and an elastic element 203 sleeved on the outside of the mounting rod 201. The two ends of the elastic element 203 are fixed to the frame 41 and the mounting block 202, respectively. In this embodiment, the elastic element 203 is preferably a spring. The elastic element 203 is used to dynamically adjust the gap between the pressure roller 10 and the roller 42 to adapt to the thickness fluctuation of the paper 60 and ensure that the friction between the roller 42 and the paper 60 is constant, thereby ensuring that the roller 42 is reliably driven by the paper 60 without slipping.

[0041] In this embodiment, the stiffness coefficient K of the preferred elastic element 203 satisfies the following: when the thickness of the paper 60 fluctuates within the range of ±20%, the pressure change between the pressure roller 10 and the roller 42 is ≤10%, so that when the thickness of the paper 60 is uneven or there is a joint, the pressure roller 10 automatically retracts to avoid paper jamming or tearing; after the paper 60 passes through, the elastic element 203 resets to maintain a constant clamping force; and the roller 42 is always reliably driven by the paper 60 to prevent the glue application position deviation caused by slippage.

[0042] like Figure 5 As shown, the control device includes a first touch switch 401 located at one end of the reciprocating screw 43 near the transmission mechanism 6 and a second touch switch 402 located at the other end of the reciprocating screw 43. In this embodiment, the first touch switch 401 and the second touch switch 402 are respectively installed at both ends of the slide groove 411. The solenoid valve 30 is fixedly connected to the slider 44. The control circuit is configured such that when the slider 44 triggers the first touch switch 401, the solenoid valve 30 is energized to open the glue gun 45; when the slider 44 triggers the second touch switch 402, the solenoid valve 30 is de-energized to close the glue gun 45. In this embodiment, reciprocating screws 43 of different lengths can be replaced according to the required spraying length of the adhesive strip, and the positions of the first touch switch 401 and the second touch switch 402 within the slide groove 411 can be changed accordingly.

[0043] To prevent residual glue from dripping from the nozzle of the glue gun 45 and contaminating the paper 60 upon closing, this embodiment includes a back-suction valve connected in series in the glue supply line of the glue gun 45. The valve core of the back-suction valve is connected to a return spring, which normally keeps the valve core in the glue supply position. To achieve mechanical linkage with the movement of the slider 44, this embodiment also includes a purely mechanical back-suction trigger mechanism for driving the valve core to retract. The back-suction trigger mechanism includes a steel wire rope, a fork, a wedge block, and a return torsion spring. One end of the steel wire rope is fixedly connected to the valve core of the back-suction valve, and the other end is fixedly connected to the frame 41. The middle section of the steel wire rope maintains a certain slack to prevent it from pulling the valve core when no external force is applied. The fork is mounted on the side wall of the slider 44 via a hinge shaft. The fork can swing around the hinge shaft within a certain angle. The head of the fork has a U-shaped... An opening is provided through which a steel wire rope passes. The tail end of the shift fork has an inclined surface facing the direction in which the slider 44 moves toward the second touch switch 402. A reset torsion spring is located between the shift fork and the slider 44. The reset torsion spring is used to keep the shift fork in its initial position when it is not subjected to external force, that is, the opening of the shift fork is basically aligned with the steel wire rope, and the steel wire rope can slide freely in the opening. A wedge block is fixedly installed on the frame 41, located beside the second touch switch 402, and corresponds to the position of the inclined surface at the tail end of the shift fork. The angle of the inclined surface of the wedge block matches the angle of the inclined surface at the tail end of the shift fork.

[0044] When slider 44 moves from first touch switch 401 to second touch switch 402 under the drive of reciprocating screw 43, the shift fork moves synchronously with slider 44. The wire rope slides freely in the opening of the shift fork and is not subjected to the tension of the shift fork. Therefore, the valve core of the suction valve remains in the glue supply position under the action of the return spring, and the glue gun 45 sprays normally. When slider 44 moves close to second touch switch 402, the inclined surface of the tail end of the shift fork begins to contact the inclined surface of the wedge block. As slider 44 continues to move, the wedge block pushes the shift fork to swing around the hinge axis, and the head of the shift fork moves away from slider 44. The steel wire rope threaded through the opening is tightened and pulled to one side. After being tensioned, the steel wire rope overcomes the elastic force of the return spring at the back suction valve. The steel wire rope pulls the valve core to move backward, generating negative pressure at the nozzle of the glue gun 45, which draws the glue residue at the nozzle back into the pipeline. At this time, the glue gun 45 is still in the spraying state, but the back suction action has been pre-activated. When the slider 44 continues to move to the position of the second touch switch 402, the slider 44 triggers the second touch switch 402, and the solenoid valve 30 controls the glue supply of the glue gun 45 to be cut off. At this time, the back suction valve is in the back suction state, and there is no glue residue at the nozzle, so there will be no dripping.

[0045] After slider 44 triggers the second touch switch 402, the reciprocating screw 43 continues to rotate, slider 44 begins to reverse direction and moves in the opposite direction. In the initial stage of slider 44 moving in the opposite direction, the inclined surface at the end of the shift fork gradually disengages from the wedge block. Under the action of the return torsion spring, the shift fork swings back to reset around the hinge axis. The opening of the shift fork returns to center with the wire rope, the wire rope loosens, the valve core of the back suction valve resets under the action of the return spring, and the glue gun 45 glue supply channel reopens, preparing for the next glue application cycle. Through the above-mentioned purely mechanical linkage structure, this embodiment achieves precise timing control of "first back suction, then glue cut-off", and does not require the addition of any electronic control components. It relies entirely on the movement of slider 44 itself to complete the back suction trigger, resulting in a compact structure and high reliability.

[0046] The basic principle of this embodiment is as follows: When the production device is started and the paper 60 is moved, the paper 60 passes between the pressure roller 10 and the roller 42. Utilizing the friction between the paper 60 and the pressure roller 10 and the roller 42, the paper 60 drives the roller 42 to rotate. The roller 42, through the output shaft 61, drives the first bevel gear 71 to rotate in the transmission cavity 621. The first bevel gear 71 drives the meshing second bevel gear 72 to rotate in the transmission cavity 621. The second bevel gear 72 drives the linkage shaft 63 to rotate in the linkage channel 622. The linkage shaft 63 drives the third bevel gear 81 to rotate in another transmission cavity 621. The third bevel gear 81 drives the fourth bevel gear 82 to rotate. The fourth bevel gear 82 drives the reciprocating screw 43 to rotate continuously around its own axis in one direction. The reciprocating screw 43 drives the slider 44 to move back and forth in the slide groove 411. When the slider 44 slides to the top of the slide groove 411, it triggers the first touch switch 401. The first touch switch 401 controls the solenoid valve 30 to open the glue gun 45 for spraying. When the slider 44 slides to the other end, it abuts against the second touch switch 402. The second touch switch 402 controls the solenoid valve 30 to close the glue gun 45. The slider 44 returns to the left without moving, and the glue gun 45 remains closed. This cycle achieves unidirectional glue application and makes the spraying speed of the glue gun 45 match the moving speed of the paper 60.

[0047] like Figures 6-7As shown, in a second aspect of this embodiment, a packaging bag is provided, which is produced by the apparatus of this embodiment. The packaging bag includes a bag body 50, a flap 501 disposed on the bag body 50, a tear line 502 disposed on the flap 501, and an easy-tear strip disposed in the area of ​​the tear line 502. The easy-tear strip area has a strip-shaped adhesive layer 503 coated by a dynamic adhesive coating portion 4. The strip-shaped adhesive layer 503 is a non-drying adhesive layer, and its surface has periodic fine stripes formed by the movement of a reciprocating screw 43. In this embodiment, a lifting handle 505 is also provided on the bag body 50, and the flap 501... A recessed groove 5012 is provided at the position of the pull handle 505. Adhesive is applied to the lower folding flap 501 through a static adhesive application area, and a sealing strip 504 is affixed to the adhesive application area. When the lower folding flap 501 is folded and attached to the bag body 50, the sealing strip 504 is peeled off from the lower folding flap 501, and the adhesive at the sealing strip 504 is used to bond the lower folding flap 501 to the bag body 50. The lower folding flap 501 also has multiple easy-tear teeth 5011 for easy tearing. The tear teeth 5011, once bonded to the bag body 50, prevent easy opening, thus avoiding the replacement or damage of items stored inside the bag during transportation. This significantly improves the safety of the items inside the bag, especially when the bag is used to package food for transportation. When the recipient receives the goods, they can easily open the bag directly through the strip adhesive layer 503, without the inconvenience caused by the tear teeth 5011 and the lower flap 501. Furthermore, the strip adhesive layer is designed to prevent irreversible damage, ensuring the recipient is aware that the bag has been opened during transportation. By incorporating the tear teeth 5011 on the lower flap 501 in conjunction with the strip adhesive layer 503, the bag is difficult to open easily during transportation, and the recipient remains unaware of the opening. However, once the goods reach the recipient, they can easily open the bag through the strip adhesive layer 503, ensuring the safety of the received goods, especially food.

[0048] 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. An apparatus for producing packaging bags, characterized in that, It includes an unwinding section (1) for releasing the paper (60), a die-cutting section (2) for opening the paper (60), a static gluing section (3) for applying glue to the opening of the packaging bag, a dynamic gluing section (4) for applying glue to the tear strip of the paper (60), and a forming section (5) for folding the paper (60). The dynamic gluing part (4) includes a frame (41) placed on the working surface for the paper (60) to pass through, a roller (42) rotatably connected to the frame (41) and abutting against the paper (60), a reciprocating screw (43) driven by the roller (42) and rotatably connected to the frame (41), a slider (44) threadedly connected to the reciprocating screw (43), and a glue gun (45) fixedly connected to the slider (44) for spraying glue onto the paper (60). The reciprocating screw (43) rotates in one direction to drive the slider (44) to move back and forth along the axial direction of the reciprocating screw (43). The slider (44) is slidably connected to the frame (41). A transmission mechanism (6) is provided between the reciprocating screw (43) and the roller (42) to make the reciprocating screw (43) and the roller (42) rotate synchronously.

2. The apparatus for producing packaging bags according to claim 1, characterized in that, The transmission mechanism (6) includes an output shaft (61) located at the roller (42) and rotated by the roller (42), and a transmission rod (62) located between the output shaft (61) and the reciprocating screw (43). The transmission rod (62) is fixedly connected to the frame (41). Transmission cavities (621) are provided at both ends of the transmission rod (62) near the output shaft (61) and the reciprocating screw (43). A linkage channel (622) is provided between the two transmission cavities (621). A linkage shaft (63) is rotatably arranged in the linkage channel (622). A first bevel gear set (7) is provided between the linkage shaft (63) and the output shaft (61) for transmitting the rotational power of the output shaft (61) to the linkage shaft (63). A second bevel gear set (8) is provided between the linkage shaft (63) and the reciprocating screw (43) for transmitting the rotational power to the reciprocating screw (43).

3. The apparatus for producing packaging bags according to claim 2, characterized in that, The first bevel gear set (7) includes a first bevel gear (71) fixedly connected to the output shaft (61) and a second bevel gear (72) fixedly connected to the linkage shaft (63), and the first bevel gear (71) meshes with the second bevel gear (72); the second bevel gear set (8) includes a third bevel gear (81) fixedly connected to the linkage shaft (63) and a fourth bevel gear (82) fixedly connected to the reciprocating lead screw (43), and the third bevel gear (81) meshes with the fourth bevel gear (82).

4. The apparatus for producing packaging bags according to claim 2, characterized in that, The transmission rod (62) is provided with a mounting bracket (9) for mounting the roller (42) at one end near the roller (42). The mounting bracket (9) includes a mounting strip (91) fixedly connected to the side wall of the transmission rod (62) and mounting plates (92) on both sides of the roller (42). The output shaft (61) of the roller (42) is rotatably connected to both mounting plates (92).

5. The apparatus for producing packaging bags according to claim 4, characterized in that, The dynamic coating section (4) also includes a pressure roller (10) for applying pressure to the paper (60) to increase the friction between the roller (42) and the paper (60). The pressure roller (10) is rotatably connected to the frame (41) and is arranged opposite to the roller (42). The paper (60) passes through the middle of the roller (42) and the pressure roller (10).

6. The apparatus for producing packaging bags according to claim 5, characterized in that, An elastic mounting device (20) for flexibly pressing the paper (60) is provided between the pressing roller (10) and the frame (41). The elastic mounting device (20) includes a mounting rod (201) fixedly connected to the frame (41), a mounting block (202) slidably connected to the mounting rod (201), and an elastic element (203) sleeved on the outside of the mounting rod (201). The two ends of the pressing roller are rotatably connected to the two mounting blocks (202) respectively. The two ends of the elastic element (203) are fixedly connected to the frame (41) and the mounting block (202) respectively. The elastic element (203) is used to dynamically adjust the gap between the pressing roller (10) and the roller (42).

7. The apparatus for producing packaging bags according to claim 1, characterized in that, The glue gun (45) is equipped with a solenoid valve (30) for controlling the glue supply of the glue gun (45). The solenoid valve (30) is fixedly connected to the slider (44). The solenoid valve (30) is equipped with a control device for controlling the unidirectional spraying of the glue gun (45). The control device includes a first touch switch (401) located at one end of the reciprocating screw (43) near the transmission mechanism (6) and a second touch switch (402) located at the other end of the reciprocating screw (43). When the slider (44) slides, it is electrically connected to the first touch switch (401) and the second touch switch (402) respectively. When the slider (44) contacts the first touch switch (401), the solenoid valve (30) controls the glue gun (45) to open. When the slider (44) abuts against the second touch switch (402), the solenoid valve (30) controls the glue gun (45) to close.

8. An apparatus for producing packaging bags according to claim 7, characterized in that, The frame (41) is provided with a slide groove (411) for allowing the slider (44) to slide. The slider (44) and the reciprocating screw (43) are both located in the slide groove (411). The first touch switch (401) and the second touch switch (402) are respectively located at both ends of the slide groove (411).

9. A packaging bag, characterized in that, The packaging bag is produced by the apparatus for producing packaging bags according to any one of claims 1-8, the packaging bag comprising a bag body (50), a flap (501) disposed on the bag body (50), a tear line (502) disposed on the flap (501), and an easy-tear strip disposed in the area of ​​the tear line (502); the easy-tear strip area has a strip of adhesive layer (503) coated by a dynamic adhesive coating portion (4).

10. A packaging bag according to claim 9, characterized in that, The strip-shaped adhesive layer (503) is a non-drying adhesive layer, and the surface of the strip-shaped adhesive layer (503) has periodic fine stripes formed by the movement of the reciprocating lead screw (43).

Images