Bottom sealing device for packaging bag, manufacturing apparatus, and manufacturing method

Abstract

This application discloses a bottom sealing device, manufacturing equipment, and manufacturing method for packaging bags. The bottom sealing device is used to seal the bottom of a cylindrical bag unit to form the bottom wall of the packaging bag. The bottom sealing device includes a frame, a first bottom sealing mechanism, and a second bottom sealing mechanism. The first bottom sealing mechanism is disposed on the frame and is used to seal a first bottom part to the bottom surface. The first bottom part is the bottom part closer to the middle support part in the bottom wall. The second bottom sealing mechanism is disposed on the frame and is located downstream of the first bottom sealing mechanism along the production direction of the packaging bag. It is used to seal a second bottom part to the bottom surface. The end of the second bottom part overlaps and is fixed to the end of the first bottom part. The second bottom sealing mechanism does not produce indentations or other marks on the side wall of the bag unit corresponding to the second bottom part during the sealing process. When applied to manufacturing equipment, it can make the final produced packaging bag more aesthetically pleasing.

Description

Technical Field

[0001] This application relates to the field of packaging bag manufacturing technology, and in particular to a bottom sealing device for use in packaging bag manufacturing equipment, and a method for manufacturing packaging bags. Background Technology

[0002] Packaging bags are used to package goods and are widely used in daily life and industrial production. Common materials include polyethylene, polypropylene, polyvinyl chloride, and paper. The shapes of these bags vary widely depending on the specific needs. Taking paper packaging bags made from roll paper using a continuous production process as an example, the process involves first forming a single roll of material into a continuous cylindrical structure. This continuous cylindrical structure is then cut into individual bag units. The bottom wall of each bag unit is then folded to one side to flatten it, leaving the bottom wall open. Finally, the two side edges of the bottom wall are bent towards the bottom wall and sealed, thus producing a complete packaging bag.

[0003] In the process of sealing the bottom wall of a packaging bag, existing technologies typically employ continuous production equipment. To ensure that the sides of the bottom wall can bend smoothly along the preset bending lines, the manufacturing equipment usually has two folding blades and slots on the conveying platform (e.g., a drum mechanism). The two folding blades are inserted into the corresponding slots to insert the bent portions of the two sides of the bottom wall. At this point, the two sides of the bottom wall will lift up. Then, the two sides of the bottom wall are bent and sealed using appropriate guiding and sealing structures. During this process, when the folding blades insert into one side of the bottom wall that coincides with the bag body unit, they also leave an insertion mark on the side wall of the bag body unit. This insertion mark cannot be eliminated after the bag body is manufactured, significantly affecting the overall aesthetics of the packaging bag.

[0004] Therefore, existing packaging bag manufacturing equipment suffers from poor aesthetics when producing packaging bags. Summary of the Invention

[0005] The purpose of this invention is to solve the problem of poor aesthetics in packaging bags produced by existing packaging bag manufacturing equipment.

[0006] To achieve the above objectives, this application provides a bottom-sealing device for a packaging bag, which seals a cylindrical bag unit to form the bottom wall of the packaging bag. The bottom wall of the packaging bag includes a central support portion and a first bottom parting surface and a second bottom parting surface located on both sides of the central support portion along the thickness direction of the packaging bag. The central support portion is bent inward relative to the side wall of the packaging bag, and the first bottom parting surface and the second bottom parting surface are bent toward the central support portion and fixed to their respective surfaces, with the opposite ends of the first bottom parting surface and the second bottom parting surface overlapping and fixed to each other. The bottom-sealing device includes a frame, a first bottom-sealing mechanism, and a second bottom-sealing mechanism. The first bottom-sealing mechanism is disposed on the frame and is used to seal the first bottom parting surface to the bottom surface. The first bottom parting surface is located closer to the central support portion of the bottom wall. The support has a bottom parting surface; the second bottom sealing mechanism is mounted on the frame and located downstream of the first bottom sealing structure along the production direction of the packaging bag, for sealing the second bottom parting surface to the bottom surface, with the end of the second bottom parting surface overlapping and fixed to the end of the first bottom parting surface; the second bottom sealing mechanism includes a limiting component mounted on the frame and a guide sealing component mounted on one side of the limiting component, the limiting component having an abutment surface extending along the production direction; and when the bag unit passes through the second bottom sealing mechanism, the abutment surface presses against the middle support of the bag unit, one side edge is aligned with the bending line of the second bottom parting surface relative to the middle support, and the guide sealing component guides the second bottom parting surface to bend relative to the middle support and overlap and fix it to the middle support and the first bottom parting surface.

[0007] By adopting the above technical solution, the bottom sealing device provided in this application includes a first bottom sealing mechanism and a second bottom sealing mechanism, and the first and second bottom sealing mechanisms are arranged as two independent bottom sealing structures along the production direction. Thus, when the bag unit passes through the workstations where the first and second bottom sealing mechanisms are located, the first and second bottom sealing mechanisms can operate independently to seal the first bottom parting surface and the second bottom parting surface, and the two sealing actions will not interfere with each other. For example, when the first bottom sealing mechanism seals the first bottom parting surface, since the first bottom parting surface is the bottom parting surface closer to the middle support part in the bottom wall, the first bottom parting surface is not attached to the side wall of the bag unit when the bag bottom is open. The first bottom sealing mechanism uses a simple... The structure allows for the sealing of the first bottom part. When the second bottom sealing mechanism seals the second bottom part, since the second bottom part is attached to the side wall of the bag unit when not sealed, and the second bottom sealing mechanism in this application includes a limiting component mounted on the frame and a guiding sealing component mounted on one side of the limiting component, and the limiting component has an abutment surface extending along the production direction; as the bag unit passes through the second bottom sealing mechanism, the abutment surface presses against the middle support portion of the bag unit, and one edge aligns with the bending line of the second bottom part relative to the middle support portion; as the bag unit gradually moves along the production direction, the guiding sealing component guides the second bottom part to bend relative to the middle support portion and overlap and fix it to the middle support portion and the first bottom part. Throughout the process, the various structures in the second bottom sealing mechanism do not create indentations or other marks on the side wall of the bag unit corresponding to the second bottom part; resulting in a more aesthetically pleasing final packaging bag.

[0008] In addition, since the first and second sealing mechanisms are set independently in the sealing device provided in this application, their sealing action will not affect the conveying of the bag unit. The packaging bag does not need to stop between the two sealing stations, which can ensure the continuous processing of the bag unit.

[0009] Furthermore, the first and second sealing mechanisms in the sealing device provided in this application can be independently designed based on the corresponding posture characteristics of the first and second bottom parting surfaces. When applied to various packaging bag manufacturing equipment, no major matching improvements are required for other structures to achieve overall coordination between the sealing device and the manufacturing equipment, which has the advantage of good applicability.

[0010] Therefore, when the sealing device provided in this application is applied to packaging bag manufacturing equipment, it can not only produce more aesthetically pleasing packaging bags while ensuring the production efficiency of the manufacturing equipment, but also be more easily adapted to other structures of the manufacturing equipment, especially when modifying old models of equipment, and the modification cost is lower.

[0011] According to the bottom sealing device for packaging bags provided in this application, the bottom sealing device further includes a bag conveying device, which is mounted on a frame and extends from the inlet of the first bottom sealing mechanism to the outlet of the second bottom sealing mechanism. The bag conveying device includes a first conveying section extending through the first bottom sealing mechanism, a second conveying section extending through the second bottom sealing mechanism, and a reversing mechanism disposed between the first conveying section and the second conveying section. The first conveying section conveys the bag unit along the production direction through the first bottom sealing mechanism with the length direction of the bag unit coinciding with the production direction. The reversing mechanism changes the orientation of the bag unit from the first conveying section so that the length direction of the bag unit is perpendicular to the production direction and conveys the bag unit to the second conveying section. The second conveying section receives the reversed bag unit and conveys the bag unit along the production direction through the second bottom sealing mechanism.

[0012] By adopting the above technical solution, this application provides a reversing mechanism between the first conveying section and the second conveying section. This reversing mechanism can reverse the direction of the bag unit after the first bottom sealing mechanism has sealed the first bottom part. This allows the bag unit to switch to different postures based on the corresponding structures and sealing actions of the first and second bottom sealing mechanisms during the bottom sealing process at the two sealing stations. For example, the first bottom sealing mechanism can achieve the sealing of the first bottom part using a simple combination of a folding knife and a pressure roller. Furthermore, the first bottom part is located near the bottom of the bag unit. After the bag unit is cut and the bottom is opened… Performing the sealing action of the first bottom part directly downstream of the bag unit's conveying direction is not only highly efficient but also beneficial to the structural design of the first bottom sealing mechanism. When the second bottom part is not sealed, it adheres to the side wall of the bag unit. This application uses a reversing mechanism to allow the bag unit to be conveyed perpendicular to the production direction, making the folding action of the second bottom part perpendicular to the conveying direction. Thus, the second bottom sealing mechanism, positioned on one side of the bag unit's conveying path, can achieve the sealing action of the second bottom part, and the folding action of the second bottom part by the second bottom sealing mechanism will not affect the normal conveying of the bag unit. This structure not only ensures continuous production of packaging bags but also allows for greater freedom in the spatial arrangement of the first and second bottom sealing mechanisms.

[0013] According to the bottom sealing device of the packaging bag provided in this application, the limiting component includes a limiting plate extending along the production direction, and one side of the limiting plate has an abutment surface extending in the horizontal direction; the guiding sealing component includes a folding component and a sealing component; wherein, the folding component is disposed on the other side of the limiting plate perpendicular to the production direction relative to the bending line, and bends the second bottom parting surface along the bending line, and the sealing component fixes the second bottom parting surface to the bottom surface.

[0014] Using the above technical solution, the contact surface of the limiting plate extends horizontally, continuously pressing the intermediate support portion during bag movement. One edge aligns with the bending line of the second bottom part relative to the intermediate support portion, allowing the second bottom part to bend at a predetermined position and angle during bending. Furthermore, the contact surface continuously presses the intermediate support portion during bag unit movement, preventing the second bottom part from easily shaking or shifting during bending. The folding component in the sealing assembly is positioned perpendicular to the production direction relative to the bending line on the other side of the limiting plate, guiding the second bottom part to bend along the bending line during bag unit transport. This ensures that during operation, the various structures of the entire second bottom sealing mechanism do not leave indentations or other marks on the side wall of the bag unit corresponding to the second bottom part.

[0015] According to the sealing device for the packaging bag provided in this application, the folding component is configured as a guide plate extending along the production direction, the guide plate having a guide surface extending in a curved manner relative to the horizontal direction, and the included angle between the guide surface and the conveying plane of the second conveying section gradually decreasing along the production direction; the sealing component is configured as a sealing pressure roller.

[0016] Using the above technical solution, the guide plate has a guide surface that extends in a curved manner relative to the horizontal direction. The curved surface design can provide a continuous and smooth guide for the second bottom parting surface. As the bag unit moves along the production direction, the second bottom parting surface will naturally change direction gradually along the shape of the curved guide surface to achieve bending.

[0017] Furthermore, the angle between the guide surface and the conveying plane of the second conveying section gradually decreases along the production direction. This results in a smoother guiding force on the second bottom parting surface when it begins to bend, preventing excessive stress concentration due to abrupt angle changes that could lead to wrinkles or damage. As the bag unit moves, the angle gradually decreases, and the guiding force gradually increases, more effectively propelling the second bottom parting surface to complete the bending action, making the bending process more stable. Moreover, the curved guide surface is relatively smooth, reducing frictional resistance between the second bottom parting surface and the guide plate during folding. Compared to guide structures with right angles or sharp edges, the curved design prevents the second bottom parting surface from being scratched or stuck during bending, allowing it to bend more smoothly along the guide surface. By setting the sealing component as a sealing pressure roller, which has rolling contact with the second bottom parting surface, the sealing pressure roller can apply uniform pressure to the second bottom parting surface during rotation, resulting in a better sealing effect.

[0018] According to the bottom sealing device of the packaging bag provided in this application, the second bottom sealing mechanism further includes a glue spraying component and an air blowing component; the glue spraying component, the air blowing component, the folding component, and the sealing component are arranged sequentially on the frame along the production direction; the glue spraying component is located at the position corresponding to the inner surface of the second bottom parting surface, and sprays glue on the part where the second bottom parting surface overlaps and is fixed with the intermediate support and the first bottom parting surface; the air blowing component is located on one side of the second bottom parting surface and blows air toward the corresponding surface of the second bottom parting surface, so that the second bottom parting surface smoothly enters the folding component.

[0019] By adopting the above technical solution, by setting up a glue spraying component, the glue spraying component will spray glue onto the inner surface of the second bottom part when working. This spraying method will make the glue more evenly coated on the inner surface of the second bottom part, which is beneficial to the subsequent bonding effect of the second bottom part.

[0020] In addition, after the second bottom part is coated with adhesive, even if it is tightly attached to the surface of the second conveying part due to factors such as increased weight, this application provides an air blowing component before the folding component. The airflow blown by the air blowing component can not only separate the second bottom part from the surface of the second conveying part, but also open the second bottom part at a certain angle before the folding component is folded. This can ensure the stability of the second bottom part when it is smoothly bent.

[0021] According to the bottom sealing device of the packaging bag provided in this application, the bag conveying device further includes an alignment adjustment mechanism disposed on the frame and located between the reversing mechanism and the limiting component. The alignment adjustment mechanism drives the bag unit reversed by the reversing mechanism to move in a direction perpendicular to the production direction, so that the bending line of the second bottom parting surface is aligned with one edge of the contact surface.

[0022] By adopting the above technical solution, even if there is a deviation between the bag unit and the conveying path of the second conveying part after the bag unit rotates, this application can adjust the position of the bag unit perpendicular to the production direction by setting an alignment adjustment mechanism between the reversing mechanism and the limiting component. The alignment adjustment mechanism can adjust the position of the bag unit perpendicular to the production direction and make the bending line of the second bottom parting surface aligned with one edge of the contact surface, thereby ensuring the success rate of sealing the second bottom parting surface and improving the aesthetics of the sealing.

[0023] According to the sealing device for the packaging bag provided in this application, both the first conveying section and the second conveying section include conveyor belts extending along the production direction, and at least the conveyor belt of the second conveying section has a gap extending along the production direction. The alignment adjustment mechanism includes a limiting baffle, an adjusting wheel, and a pressing limiting component. The limiting baffle extends along the production direction and is adjustablely disposed on the frame, located on the side corresponding to the bottom wall of the packaging bag. The adjusting wheel is rotatably disposed on the frame about the production direction and at least partially protrudes from the gap of the second conveying section in the vertical direction. The pressing limiting component is vertically and vertically connected to the frame and located above the adjusting wheel.

[0024] Using the above technical solution, a limiting baffle extends along the production direction and is adjustablely positioned on the frame, located on the side corresponding to the bottom wall of the packaging bag. During bag unit alignment, the limiting baffle serves as a fixed reference boundary, limiting the bottom of the bag unit. An adjusting wheel is rotatably mounted on the frame around the production direction and at least partially protrudes into the gap of the second conveying section in the vertical direction. When the bag unit is conveyed to the position of the adjusting wheel, the rotation of the adjusting wheel generates a lateral thrust on the bag unit, thereby adjusting its position. Simultaneously, a pressing limiting component is vertically and elliptically connected to the frame and located above the adjusting wheel, allowing downward pressure on the bag unit. This ensures the bag unit maintains a stable posture while being pushed by the adjusting wheel, preventing it from tilting or wobbling during position adjustment.

[0025] According to the sealing device for the packaging bag provided in this application, the reversing mechanism includes a corner blocking member. The corner blocking member is disposed at the inlet of the second conveying section, corresponding to the corner of the bottom wall of the packaging bag near the limiting component. The corner of the bottom wall of the bag unit passing from the first conveying section to the inlet of the second conveying section abuts against the corner blocking member, and the bag unit rotates around the corner blocking member to change to an attitude perpendicular to the production direction.

[0026] Using the above technical solution, when the bottom wall of the bag unit, near the corner of the limiting component, abuts against the corner blocking member at the entrance of the second conveying section after passing from the first conveying section, the bag unit contacts the blocking member and rotates around it to complete the reversal. The entire process does not require complex mechanical movements or lengthy adjustments. Furthermore, this reversal action can match the continuous conveying speed of the conveyor belt, preventing interruptions or stops in the conveying process, thus ensuring the continuity and smoothness of production and improving production efficiency.

[0027] According to the bottom sealing device of the packaging bag provided in this application, the corner blocking member is configured as an inverted conical blocking bar; and the reversing mechanism also includes a transfer component, which is vertically mounted on the frame, located on one side of the corner blocking member, and closer to the middle position of the inlet of the second conveying section in the direction perpendicular to the production direction; when the corner of the bottom wall of the bag unit abuts against the corner blocking member, the transfer component presses the bottom wall of the bag unit and rotates to make the bag unit rotate around the corner blocking member.

[0028] By employing the above technical solution, the unique shape of the inverted conical blocking bar ensures that during the bag unit's conveying process, as one corner of its bottom wall gradually approaches the inverted conical blocking bar, the conical side provides a gradually converging guide path for the bag unit. This prevents the corner of the bag unit's bottom wall from colliding with the corner blocking member and causing it to lift, thus affecting the bag unit's rotation. The transfer component is vertically mounted on the frame and positioned closer to the center of the second conveying section's inlet. When one corner of the bag unit's bottom wall abuts against the corner blocking member, the transfer component can descend and press down on the bottom wall of the bag unit, rotating while pressing down. This prevents the bag unit from slipping or deviating from its rotation trajectory during rotation. This ensures the bag unit rotates at a predetermined speed and angle, further enhancing the stability of the reversing process. Even when handling bag units with significant weight or low surface friction, the transfer component can ensure smooth reversing through pressing.

[0029] According to the bottom sealing device of the packaging bag provided in this application, the reversing mechanism further includes an extrusion conveying wheel disposed on the upstream side of the transfer component in the production direction. The extrusion conveying wheel is rotatably connected to the frame. The transfer component includes a lifting component disposed on the frame and an extrusion rotating head rotatably connected to the lifting end of the lifting component. The extrusion conveying wheel rotates and moves towards the transfer component to transport the bag body unit in the production direction. The lifting component, in conjunction with the extrusion rotating head, extrudes the bottom wall of the bag body unit, and the extrusion rotating head rotates synchronously with the bag body unit.

[0030] With the above technical solution, the extrusion conveyor wheel is rotatably connected to the frame and moves along the production direction toward the transfer component to transport the bag unit. During the entire transport process, it can provide continuous conveying force to the bag unit, which can make the bag unit approach the transfer component at a uniform speed and in a stable state, thereby ensuring the stability of the bag unit reversal.

[0031] According to the sealing device for the packaging bag provided in this application, the extrusion conveyor wheel has an arc-shaped extrusion surface and an avoidance notch formed sequentially along its circumference, and the arc length of the arc-shaped extrusion surface is less than the length of the bag unit.

[0032] By adopting the above technical solution, an arc-shaped extrusion surface and an avoidance notch are sequentially formed along the circumference of the extrusion conveyor wheel. By adjusting the contact angle between the extrusion conveyor wheel and the bag unit, the arc-shaped extrusion surface contacts the bag unit, and the avoidance notch can avoid features such as the handle and bag opening of the bag unit, preventing the extrusion conveyor wheel from interfering too much with the bag unit, which could cause the bag unit to stop or fail to change direction.

[0033] According to the bottom sealing device of the packaging bag provided in this application, the first bottom sealing mechanism includes a rotating shaft rotatably connected to the frame, a pressing knife and a sealing wheel arranged sequentially on the rotating shaft along the circumference of the rotating shaft; the rotating shaft rotates in sequence, and the pressing knife abuts against the bending line of the first bottom parting surface and the sealing wheel rolls against the first bottom parting surface.

[0034] By adopting the above technical solution, this application sets the first bottom sealing mechanism to include a pressure knife and a sealing wheel arranged sequentially on the rotating shaft along the circumference. When sealing the first bottom split surface, the sealing of the first bottom split surface can be achieved by the simple cooperation of the pressure knife and the sealing wheel. There is no need to set up a complex structure, which helps to simplify the structure of the first bottom sealing mechanism and makes it easier to disassemble and assemble the first bottom sealing mechanism.

[0035] This application also provides packaging bag manufacturing equipment, comprising, arranged sequentially along the production direction: a base material supply device, a forming device, a sealing device, a bottom sealing device as described above, a waste discharge device, and a collection device; wherein, the base material supply device is used to convey sheet-like base material to the next work station; the forming device receives the base material conveyed by the base material supply device and forms the base material into a continuous cylindrical structure; the sealing device includes a large drum body, on which a cutting mechanism and a bottom opening mechanism are arranged sequentially along the production direction; the cutting mechanism is used to cut the cylindrical structure received by the sealing device... The bag is cut into individual bag units. The bottom opening mechanism is used to bend the bottom wall of the individual bag unit toward one side of the bag unit to form a middle support part, a first bottom parting surface and a second bottom parting surface located on both sides of the middle support part; the first bottom sealing mechanism is set on the drum body and located downstream of the bottom opening assembly along the production direction, and is used to seal the first bottom parting surface and the second bottom parting surface to the middle support part respectively; the waste discharge device is used to inspect the bags sealed by the second bottom sealing mechanism and reject waste products; the collection device is used to collect qualified packaging bags that have not been rejected by the waste discharge device.

[0036] By adopting the above technical solution, the packaging bag manufacturing equipment provided in this application, due to the inclusion of the sealing device with the aforementioned structure, ensures that during packaging bag manufacturing, the first sealing mechanism located on the drum body only seals the first bottom part. When the second sealing mechanism seals the second bottom part, it includes a limiting component mounted on the frame and a guiding sealing component located on one side of the limiting component, with the limiting component having an abutment surface extending along the production direction. As the bag unit passes through the second sealing mechanism, the abutment surface presses against the middle support portion of the bag unit, and one edge aligns with the bending line of the second bottom part relative to the middle support portion. As the bag unit gradually moves along the production direction, the guiding sealing component guides the second bottom part to bend relative to the middle support portion and overlap and fix it to the middle support portion and the first bottom part. Throughout the process, the various structures in the second sealing mechanism do not create indentations or other marks on the side wall of the bag unit corresponding to the second bottom part; resulting in a more aesthetically pleasing final packaging bag.

[0037] This application also provides a method for manufacturing a packaging bag, comprising the following steps:

[0038] The sheet-like base material is molded into a continuous cylindrical structure;

[0039] The continuous cylindrical structure is cut into individual bag units;

[0040] The bottom wall of each individual bag unit is bent toward one side of the bag unit;

[0041] The bag unit is transported along the production direction with its length direction aligned with the production direction.

[0042] The first bottom part of the bottom wall is sealed to the middle support part of the bottom wall;

[0043] The orientation of the bag unit is changed so that the length direction of the bag unit is perpendicular to the production direction;

[0044] The second bottom part of the bottom wall is sealed to the middle support part of the bottom wall.

[0045] Using the above technical solution, the manufacturing method provided in this application, when sealing the bottom of the bag unit, first seals the first bottom parting surface with the length direction of the bag unit coinciding with the production direction. After the first bottom parting surface is sealed, the orientation of the bag unit is changed so that the length direction of the bag unit is perpendicular to the production direction. Then, the second bottom parting surface of the bottom wall is sealed to the middle support part of the bottom wall. In this process, the first and second bottom parting surfaces of the bag unit are sealed in two steps, and the bag unit is switched to different orientations in the two steps. Based on the structural characteristics of the first and second bottom parting surfaces, sealing mechanisms adapted to them can be set at two sealing stations. This not only helps to eliminate the indentation on the side wall of the bag unit corresponding to the second bottom parting surface, but also does not require major matching modifications to other structures when applied to various packaging bag manufacturing equipment, thus achieving overall coordination between this sealing device and the manufacturing equipment, and has the advantage of good applicability. Furthermore, the two sealing mechanisms can be set up independently, and their sealing action will not affect the conveying of the bag unit. The packaging bag does not need to stop between the two sealing stations, which can ensure the continuous processing of the bag unit.

[0046] According to the packaging bag manufacturing method provided in this application, before sealing the second bottom part of the bottom wall to the middle support portion of the bottom wall, the method further includes: aligning the bending line of the second bottom part in the bag body unit with the edge of the abutting surface of the limiting component in the second bottom sealing mechanism.

[0047] By adopting the above technical solution, even if there is a deviation between the conveying path of the bag unit and the second conveying part after the bag unit rotates, this application can ensure the success rate of sealing the second bottom part and improve the aesthetics of sealing by aligning the bending line of the second bottom part with the edge of the contact surface of the limiting component in the second bottom sealing mechanism.

[0048] This application also provides a packaging bag, which is manufactured using the above-described manufacturing method. The packaging bag includes a bag body with a cavity. The bag body includes a pair of front walls disposed opposite each other in the thickness direction of the bag body, a pair of side walls disposed opposite each other in the width direction of the bag body, and a bottom wall disposed at the bottom of the bag body in the height direction of the bag body. The pair of front walls and the pair of side walls surround the top of the bag body to form a bag opening. The bottom wall includes a central support portion and a first bottom parting surface and a second bottom parting surface located on both sides of the central support portion in the thickness direction of the packaging bag. The central support portion is bent inward relative to the side walls of the packaging bag. The first bottom parting surface and the second bottom parting surface are bent toward the central support portion and fixed to the corresponding surfaces of the central support portion. The opposite ends of the first bottom parting surface and the second bottom parting surface overlap and are fixed to each other. Furthermore, the outer wall surface of one of the front walls is a smooth plane, and a bending line is formed on the other front wall near the bottom surface. The other front wall is a smooth plane from the bending line to the bag opening.

[0049] By adopting the above technical solution, the packaging bag provided in this application is made by the above method. Because there are no indentations on the side wall of the packaging bag corresponding to the second bottom part, the packaging bag is not only aesthetically pleasing, but also will not bend or tip over due to indentations when unfolded, thus having better stability. This makes it easier for users to put items into the bag, thereby improving the user experience. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of the sealing device for the packaging bag provided in Embodiment 1 of this application;

[0051] Figure 2 This is a schematic diagram of the structure of the first sealing mechanism in the sealing device for the packaging bag provided in Embodiment 1 of this application;

[0052] Figure 3 This is a schematic diagram of the structure of the second sealing mechanism in the sealing device for the packaging bag provided in Embodiment 1 of this application;

[0053] Figure 4 A schematic diagram of the reversing mechanism in the bottom sealing device of the packaging bag provided in Embodiment 1 of this application;

[0054] Figure 5 This is a schematic diagram of the alignment adjustment mechanism in the bottom sealing device of the packaging bag provided in Embodiment 1 of this application;

[0055] Figure 6 This is a schematic diagram of the folding component in the bottom sealing device of the packaging bag provided in Embodiment 1 of this application;

[0056] Figure 7 This is a schematic diagram of the structure of the packaging bag manufacturing equipment provided in Embodiment 2 of this application;

[0057] Figure 8 A flowchart illustrating the method for manufacturing the packaging bag provided in Embodiment 3 of this application;

[0058] Figure 9 This is a schematic diagram of the structure of the packaging bag provided in Embodiment 4 of this application;

[0059] Figure 10 This is a schematic diagram of the structure of the packaging bag in the cut bag unit provided in Embodiment 4 of this application;

[0060] Figure 11 This is a schematic diagram of the packaging bag provided in Embodiment 4 of this application with the bottom of the bag in an open state;

[0061] Figure 12 This is a schematic diagram of the structure in which the first bottom part of the packaging bag is sealed, as provided in Embodiment 4 of this application.

[0062] Explanation of reference numerals in the attached figures:

[0063] 10. Packaging bags;

[0064] 101. First bottom dividing surface; 102. Second bottom dividing surface; 103. Intermediate support section;

[0065] 100. Bottom sealing device;

[0066] 110. First bottom sealing mechanism;

[0067] 111. Rotary shaft; 112. Pressing knife; 113. Sealing wheel;

[0068] 120. Second bottom sealing mechanism;

[0069] 121. Limiting component; 122. Guide sealing component; 1221. Folding component; 12210. Guide surface; 1222. Sealing component; 123. Adhesive spraying component; 124. Air blowing component;

[0070] 130. Bag conveying device;

[0071] 131. First conveying section; 132. Second conveying section; 133. Reversing mechanism; 1331. Corner blocking member; 1332. Transfer component; 1333. Extrusion conveying wheel; 134. Alignment adjustment mechanism; 1341. Limiting baffle; 1342. Adjusting wheel; 1343. Pressing limiting component;

[0072] 140. Rack;

[0073] 200. Cylindrical forming device;

[0074] 300. Sealing device;

[0075] 400. Waste discharge device. Detailed Implementation

[0076] The sealing process is a crucial step in packaging bag manufacturing, especially for paper bags made from roll paper using continuous production processes. The sealing point is typically at the bottom of the bag, requiring the bottom of each individual bag unit to be sealed before a complete bag can be produced. Current technologies often employ continuous production equipment to seal the two bottom sections of a bag unit at a single station. However, before sealing, these two sections are opened and flattened, parallel to the length of the bag unit; one bottom section is then pressed against the side wall of the bag unit. This results in the sealing mechanism's folding blade pressing against the side wall of the bag unit when one bottom section is sealed, ultimately causing noticeable indentations on the side wall of the finished bag. This not only affects the appearance but also the stability of the bag when open.

[0077] In response, this application proposes a bottom sealing device for packaging bags. If the packaging bag manufacturing equipment adopts this bottom sealing device, it can not only produce more aesthetically pleasing packaging bags while ensuring the production efficiency of the manufacturing equipment, but also make it easier to adapt to other structures of the manufacturing equipment, especially when modifying old machines, and the modification cost is lower.

[0078] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0079] Example 1:

[0080] like Figure 1 As shown, this embodiment provides a bottom sealing device 100 for a packaging bag, which seals the bottom of a cylindrical bag unit to form the bottom wall of the packaging bag 10.

[0081] It should be understood that the cylindrical bag unit refers to the tubular unit 200 of the manufacturing equipment that folds and seals the sheet-like base material, and then cuts it into individual bag units 104 using a cutting device (see...). Figure 9 ).

[0082] The packaging bag 10 can refer to a packaging bag 10 made of various materials such as paper and plastic, and the packaging bag 10 has an opening and a handle at the top and a bottom wall at the bottom.

[0083] In this embodiment, the structure of the packaging bag 10 can be referred to in Embodiment 4. Figures 8 to 11 The bottom wall of the packaging bag 10 includes a central support portion 103 and a first bottom parting surface 101 and a second bottom parting surface 102 located on both sides of the central support portion 103 along the thickness direction of the packaging bag 10. The central support portion 103 is bent inward relative to the side wall of the packaging bag 10. The first bottom parting surface 101 and the second bottom parting surface 102 are bent toward the central support portion 103 and fixed to the corresponding surfaces of the central support portion 103. The opposite ends of the first bottom parting surface 101 and the second bottom parting surface 102 overlap and are fixed to each other.

[0084] like Figure 1 As shown, the bottom sealing device 100 is described below:

[0085] In this embodiment, the bottom sealing device 100 includes a frame 140, a first bottom sealing mechanism 110, and a second bottom sealing mechanism 120.

[0086] Specifically, regarding the frame 140, as the supporting structure of the entire device, the frame 140 can be made of high-strength metal materials, such as stainless steel or aluminum alloy, to ensure the stability and reliability of the device during operation.

[0087] The first bottom sealing mechanism 110 is mounted on the frame 140 and is used to seal the first bottom part 101 to the bottom surface. The first bottom part 101 is the bottom part of the bottom wall that is closer to the middle support part 103.

[0088] In this embodiment, the structure of the first bottom sealing mechanism 110 is not limited. For example, it can be achieved by using a pressure roller and a robotic arm to seal the first bottom split surface 101.

[0089] In one implementation, such as Figure 2 As shown, it can also include a rotating shaft 111 rotatably connected to the frame 140. A pressing knife 112 and a sealing wheel 113 are sequentially arranged on the rotating shaft along the circumference of the rotating shaft 111. When the rotating shaft rotates, the pressing knife 112 abuts against the bending line of the first bottom parting surface 101, and the sealing wheel 113 rolls on the first bottom parting surface 101.

[0090] Specifically, the rotating shaft 111 can be connected to the frame 140 via bearings, and the pressure knife 112 and sealing wheel 113 can be made of wear-resistant and high-strength materials. During the sealing process, when the bag unit 104 is conveyed to the first bottom sealing mechanism 110 station, the rotating shaft starts to rotate. During the rotation of the rotating shaft 111, the pressure knife 112 will first abut against the bending line of the first bottom parting surface 101, applying pressure to the first bottom parting surface 101 to make it bend along the bending line; subsequently, the sealing wheel 113 or pressing plate or other mechanisms can be used to press the first bottom parting surface 101 to achieve the sealing of the first bottom parting surface 101.

[0091] It should be understood that the sealing wheel 113 can seal the first bottom parting surface 101 to the bottom surface by means of heating or pressurization, thus completing the sealing operation of the first bottom parting surface 101. Alternatively, the bag unit 104 may be conveyed to the first bottom sealing mechanism 110 station and pre-applied with adhesive, and the first bottom parting surface 101 may be pressed and bonded to the intermediate support part 103. Since the first bottom parting surface 101 is the bottom parting surface closer to the intermediate support part 103 in the bottom wall, when the bag bottom is open, the first bottom parting surface 101 is not attached to the side wall of the bag unit 104. This structure is simple and the operation is independent, and the sealing is completed by the combination of the pressure knife 112 and the sealing wheel 113.

[0092] like Figure 3 As shown, the second bottom sealing mechanism 120 is disposed on the frame 140 and located downstream of the first bottom sealing mechanism 110 along the production direction of the packaging bag 10. It is used to seal the second bottom parting surface 102 to the bottom surface, and the end of the second bottom parting surface 102 overlaps and is fixed to the end of the first bottom parting surface 101.

[0093] In this embodiment, the second sealing mechanism 120 includes a limiting component 121 disposed on the frame 140, and a guide sealing component 122 disposed on one side of the limiting component 121.

[0094] Specifically, the limiting component 121 has an abutting surface extending along the production direction; and when the bag unit passes the second bottom sealing mechanism 120, the abutting surface presses against the middle support portion 103 of the bag unit, and one side edge of the abutting surface is aligned with the bending line of the second bottom parting surface 102 relative to the middle support portion 103, and the guiding sealing component 122 guides the second bottom parting surface 102 to bend relative to the middle support portion 103 and overlap and fix it on the middle support portion 103 and the first bottom parting surface 101.

[0095] The bottom sealing device 100 provided in this embodiment utilizes the above-described solution. Since the bottom sealing device 100 includes a first bottom sealing mechanism 110 and a second bottom sealing mechanism 120, and the first bottom sealing mechanism 110 and the second bottom sealing mechanism 120 are arranged sequentially along the production direction, they are two independent bottom sealing structures. Thus, when the bag unit passes through the workstations where the first bottom sealing mechanism 110 and the second bottom sealing mechanism 120 are located, the first bottom sealing mechanism 110 and the second bottom sealing mechanism 120 can operate independently to seal the first bottom parting surface 101 and the second bottom parting surface 102, and the two sealing actions will not interfere with each other.

[0096] During the process of sealing the bottom of the bag, when the first bottom sealing mechanism 110 seals the first bottom part 101, since the first bottom part 101 is the bottom part closer to the middle support part 103 in the bottom wall, the first bottom part 101 is not attached to the side wall of the bag unit. Based on the characteristics of the first bottom part 101, the first bottom sealing mechanism 110 can achieve the sealing of the first bottom part 101 with a simple structure.

[0097] When the second bottom sealing mechanism 120 seals the second bottom parting surface 102, since the second bottom parting surface 102 is not sealed, it is attached to the side wall of the bag unit. In this embodiment, the second bottom sealing mechanism 120 includes a limiting component 121 disposed on the frame 140 and a guide sealing component 122 disposed on one side of the limiting component 121. The limiting component 121 has an abutment surface extending along the production direction. When the bag unit passes through the second bottom sealing mechanism 120, the abutment surface presses against the middle support portion 103 of the bag unit, and one edge is aligned with the bending line of the second bottom parting surface 102 relative to the middle support portion 103. As the bag unit gradually moves along the production direction, the guide sealing component 122 guides the second bottom parting surface 102 to bend relative to the middle support portion 103 and overlap and fix it on the middle support portion 103 and the first bottom parting surface 101. Throughout the process, the various structures in the second bottom sealing mechanism 120 do not create indentations or other marks on the side wall of the bag unit corresponding to the second bottom dividing surface 102, resulting in a more aesthetically pleasing final packaging bag 10.

[0098] Furthermore, in the sealing device 100 provided in this embodiment, since the first sealing mechanism 110 and the second sealing mechanism 120 are set independently, their sealing action will not affect the conveying of the bag unit. The packaging bag 10 does not need to stop between the two sealing stations, which can ensure the continuous processing of the bag unit.

[0099] Furthermore, the first sealing mechanism 110 and the second sealing mechanism 120 in the sealing device 100 provided in this application can be independently designed based on the corresponding posture characteristics of the first bottom parting surface 101 and the second bottom parting surface 102. When applied to various packaging bag manufacturing equipment, no major matching modifications to other structures are required to achieve overall cooperation between this sealing device 100 and the manufacturing equipment, which has the advantage of good applicability. Therefore, when the sealing device 100 provided in this embodiment is applied to packaging bag manufacturing equipment, it can not only produce more aesthetically pleasing packaging bags 10 while ensuring the production efficiency of the manufacturing equipment, but also is easier to adapt to other structures of the manufacturing equipment, especially when retrofitting old models of equipment, which is easier and has lower retrofitting costs.

[0100] Furthermore, in this embodiment, the first bottom sealing mechanism 110 and the second bottom sealing mechanism 120 can be structures with built-in conveying functions, or they can be equipped with additional conveying devices.

[0101] In one implementation, such as Figure 1 and Figure 4 As shown, the bottom sealing device 100 also includes a bag conveying device 130, which is mounted on the frame 140 and extends from the inlet of the first bottom sealing mechanism 110 to the outlet of the second bottom sealing mechanism 120.

[0102] Regarding the bag conveying device 130, in this embodiment, the bag conveying device 130 includes a first conveying section 131, a second conveying section 132, and a reversing mechanism 133 disposed between the first conveying section 131 and the second conveying section 132. The first conveying section 131 extends through the first bottom sealing mechanism 110, and the second conveying section 132 extends through the second bottom sealing mechanism 120.

[0103] Specifically, the first conveying section 131 conveys the bag unit along the production direction with its length direction coinciding with the production direction, passing through the first bottom sealing mechanism 110. The reversing mechanism 133 changes the orientation of the bag unit from the first conveying section 131 so that the length direction of the bag unit is perpendicular to the production direction and conveys the bag unit to the second conveying section 132. The second conveying section 132 receives the reversed bag unit and conveys it along the production direction through the second bottom sealing mechanism 120. This allows the bag unit to switch to different orientations based on the corresponding structures and sealing actions of the first bottom sealing mechanism 110 and the second bottom sealing mechanism 120 when it is being sealed at the two bottom sealing stations.

[0104] Using this scheme, the first bottom sealing mechanism 110 can achieve the sealing of the first bottom parting surface 101 by combining the simple structure of the pressure knife 112 and the sealing wheel 113. Since the first bottom parting surface 101 is close to the bottom of the bag unit, after the bag unit is cut and the bottom is opened, the sealing action of the first bottom parting surface 101 can be directly performed on the downstream side of the bag unit conveying direction, which is not only efficient but also beneficial to the structural design of the first bottom sealing mechanism 110. When the second bottom parting surface 102 is not sealed, it is attached to the side wall of the bag unit. This application can make the bag unit conveyed along the vertical production direction by means of the reversing mechanism 133, so that the folding action of the second bottom parting surface 102 is perpendicular to the conveying direction. In this way, the second bottom sealing mechanism 120 can be set on one side of the bag unit conveying path to achieve the sealing action of the second bottom parting surface 102. Moreover, the folding action of the second bottom sealing mechanism 120 on the second bottom parting surface 102 will not affect the normal conveying of the bag unit. This structure not only ensures the continuous production of the packaging bag 10, but also allows for greater freedom in the spatial arrangement of the first bottom sealing mechanism 110 and the second bottom sealing mechanism 120.

[0105] Furthermore, based on the aforementioned bag conveying device 130, even if there is a deviation between the conveying path of the bag unit and the second conveying section 132, in this embodiment, such as Figure 5 As shown, the bag conveying device 130 may also include an alignment adjustment mechanism 134. The alignment adjustment mechanism 134 is disposed on the frame 140 and located between the reversing mechanism 133 and the limiting component 121. The alignment adjustment mechanism 134 drives the bag unit reversed by the reversing mechanism 133 to move in a direction perpendicular to the production direction, so that the bending line of the second bottom parting surface 102 is aligned with one edge of the contact surface, thereby ensuring the success rate of sealing the second bottom parting surface 102 and improving the aesthetics of the sealing.

[0106] The structure of the alignment adjustment mechanism 134 is not limited; for example, it can be configured as an electric adjustment push rod, a drag suction cup, etc.

[0107] In one embodiment, the alignment adjustment mechanism 134 includes a limiting baffle 1341, an adjusting wheel 1342, and a pressing limiting component 1343; the limiting baffle 1341 extends along the production direction and is adjustablely disposed on the frame 140, and is located on the side corresponding to the bottom wall of the packaging bag 10; the adjusting wheel 1342 is rotatably disposed on the frame 140 about the production direction, and the top of the adjusting wheel 1342 protrudes above the gap of the second conveying section 132 in the vertical direction; the pressing limiting component 1343 is vertically and vertically connected to the frame 140 above the adjusting wheel 1342, for example, it can be an electric pressure rod disposed above the adjusting wheel 1342, and the end of the electric pressure rod has a pressing head.

[0108] Both the first conveying section 131 and the second conveying section 132 may include conveyor belts extending along the production direction. The gap in the second conveying section 132 refers to the fact that the conveyor belt may consist of 5 or 6 conveyor belts arranged side by side, and there is a gap between the two conveyor belts extending along the production direction.

[0109] In this embodiment, a limiting baffle 1341 extends along the production direction and is adjustablely positioned on the frame 140, located on the side corresponding to the bottom wall of the packaging bag 10. During bag unit alignment, the limiting baffle 1341 serves as a fixed reference boundary, limiting the bottom of the bag unit. An adjusting wheel 1342 is rotatably mounted on the frame 140 around the production direction, and its top protrudes vertically beyond the gap of the second conveying section 132. When the bag unit is conveyed to the position of the adjusting wheel 1342, the rotation of the adjusting wheel 1342 generates a lateral thrust on the bag unit, thereby adjusting the position of the bag unit. Simultaneously, a pressing limiting component 1343 is vertically and vertically connected to the frame 140 and located above the adjusting wheel 1342, allowing it to press down on the bag unit. This ensures that the bag unit maintains a stable posture while being pushed by the adjusting wheel 1342, preventing the bag unit from tilting or wobbling during position adjustment.

[0110] It should be understood that, in this embodiment, a motor that drives the adjustment wheel 1342 to rotate can be provided on one side of the adjustment wheel 1342. When the bag unit is transported to the position of the adjustment wheel 1342, the motor drives the adjustment wheel 1342 to rotate and generate a lateral thrust on the bag unit. In this embodiment, lateral refers to the direction perpendicular to the production direction.

[0111] Furthermore, in the bag conveying device 130, the reversing mechanism 133 may include a corner blocking member 1331, which is disposed at the entrance of the second conveying section 132 and located at a position corresponding to the corner of the bottom wall of the packaging bag 10 near the limiting component 121.

[0112] In use, the bottom wall of the bag unit, near the limit assembly 121, abuts against the corner blocking member 1331 at the corner of the first conveying section 131 as it passes through the entrance of the second conveying section 132. The bag unit rotates around the corner blocking member 1331 to change its posture to be perpendicular to the production direction. The entire process does not require complex mechanical movements or lengthy adjustments. Furthermore, this reversing action can match the continuous conveying speed of the conveyor belt, preventing interruptions or stops in the conveying process, thus ensuring the continuity and smoothness of production and improving production efficiency.

[0113] The structure of the corner blocking member 1331 is not limited; for example, it can be an arc-shaped stop or a tapered stop.

[0114] In one implementation, such as Figure 4 As shown, the corner blocking member 1331 is set as an inverted conical blocking rod. The unique shape of the inverted conical blocking rod allows the bag unit to receive a gradually converging guide path as the corner of its bottom wall gradually approaches the inverted conical blocking rod during the bag unit's transport process. This prevents the corner of the bag unit's bottom wall from colliding with the corner blocking member 1331 and tilting upwards, thus affecting the bag unit's rotation.

[0115] Furthermore, in this embodiment, the reversing mechanism 133 also includes a transfer component 1332, which is vertically mounted on the frame 140 and located on one side of the corner blocking member 1331. The transfer component 1332 is closer to the middle position of the inlet of the second conveying section 132 in a direction perpendicular to the production direction.

[0116] When one corner of the bottom wall of the bag unit abuts against the corner blocking member 1331, the transfer member 1332 presses down on the bottom wall of the bag unit and rotates it, causing the bag unit to rotate around the corner blocking member 1331. This prevents the bag unit from slipping or deviating from its rotation trajectory during rotation. Rotating the bag unit at a predetermined speed and angle further enhances the stability of the reversing process. Even when handling bag units that are heavy or have low surface friction, the transfer member 1332 can ensure smooth reversing by pressing down.

[0117] The structure of the transfer component 1332 is not limited. For example, it can be configured as an automatically retractable electric wheel, or as a telescopic rod and a rotating head, with the rotating head connected to the end of the telescopic rod.

[0118] In one embodiment, the transfer component 1332 may include a lifting component and a compression rotating head. The lifting component is mounted on the frame 140, and the compression rotating head is rotatably connected to the lifting component. The lifting component may be equipped with an electric or pneumatic telescopic rod. The lifting component, in conjunction with the compression rotating head, compresses the bottom wall of the bag unit, and the compression rotating head rotates synchronously with the bag unit.

[0119] Furthermore, in this embodiment, the reversing mechanism 133 may also include a compression conveying wheel 1333 disposed on the upstream side of the transfer component 1332 in the production direction. The compression conveying wheel 1333 is rotatably connected to the frame 140. The compression conveying wheel 1333 rotates and moves the bag unit towards the transfer component 1332 in the production direction. In this way, it can provide a continuous conveying force to the bag unit during the entire conveying process, so that the bag unit can approach the transfer component 1332 at a uniform speed and in a stable state, thereby ensuring the stability of the bag unit reversal.

[0120] In this embodiment, the shaft of the extrusion conveyor wheel 1333 can be driven by a chain to the drive motor of the conveyor belt, or a separate drive motor can be set on the frame 140, located on one side of the extrusion conveyor wheel 1333, and the drive motor can be directly fixedly connected to the shaft of the extrusion conveyor wheel 1333.

[0121] Regarding the extrusion conveyor wheel 1333, it should be understood in this embodiment that the extrusion conveyor wheel 1333 has an arc-shaped extrusion surface and a clearance notch formed sequentially along its circumference, and the arc length of the arc-shaped extrusion surface is less than the length of the bag unit. In this way, by adjusting the contact angle between the extrusion conveyor wheel 1333 and the bag unit, the arc-shaped extrusion surface contacts the bag unit, and the clearance notch can avoid features such as the handle and bag opening of the bag unit, preventing the extrusion conveyor wheel 1333 from interfering too much with the bag unit, causing the bag unit to stop or fail to change direction.

[0122] Based on the above structure, after the bag unit is reversed, it is conveyed to the second conveying section 132. The second bottom sealing mechanism 120 seals the second bottom parting surface 102 of the bag unit. The second bottom sealing mechanism 120 and its working principle are further described below:

[0123] Specifically, such as Figure 3As shown, the structures of the limiting component 121 and the guiding sealing component 122 in the second bottom sealing mechanism 120 are not limited. For example, the limiting component 121 can be a pressure roller, pressure plate, or other structure, and the guiding sealing component 122 can be an ultrasonic ironing plate. The ultrasonic ironing plate can be a swingable guiding structure. When the bag unit is conveyed through the guiding sealing component 122, the ultrasonic ironing plate swings, causing the second bottom parting surface 102 to fold over and simultaneously iron and seal the second bottom parting surface 102. Of course, this structure is suitable for bag units made of easily ironable materials (such as plastic film, non-woven fabric, etc.). The guiding sealing component 122 can also be composed of a folding component 1221 and a sealing component 1222. The folding component 1221 is used to bend the second bottom parting surface 102 first, and then the sealing component 1222 is used to seal the second bottom parting surface 102.

[0124] In this embodiment, the limiting component 121 includes a limiting plate extending along the production direction, and one side of the limiting plate has an abutment surface extending in the horizontal direction. During the movement of the bag body, the intermediate support portion 103 is continuously pressed, and one side edge is aligned with the bending line of the second bottom parting surface 102 relative to the intermediate support portion 103. This allows the second bottom parting surface 102 to bend at a predetermined position and angle during the bending process. Moreover, the abutment surface can continuously press the intermediate support portion 103 during the movement of the bag body unit, so that the second bottom parting surface 102 will not shake or shift during the bending process. The guide sealing assembly 122 includes a folding component 1221 and a sealing component 1222. The folding component 1221 is positioned on the other side of the limiting plate perpendicular to the production direction relative to the bending line, and bends the second bottom parting surface 102 along the bending line. The sealing component 1222 fixes the second bottom parting surface 102 to the bottom surface, so that during the operation of the entire second bottom sealing mechanism 120, the various structures will not produce indentations or other marks on the side wall of the bag unit corresponding to the second bottom parting surface 102.

[0125] The structure of the folding component 1221 is not limited. For example, it can be a rotatable folding plate. When the bag unit passes through the folding component 1221, the folding component 1221 flips over to bend the second bottom parting surface 102. The sealing component 1222 can be set as a heat-sealing wheel 113. After the second bottom parting surface 102 is bent, when the bag unit is conveyed through the heat-sealing wheel 113, the heat-sealing wheel 113 rolls and heats the second bottom parting surface 102 to achieve sealing. Similarly, this structure is suitable for the bag unit 104 to be made of easily heat-sealed materials (such as plastic film, non-woven fabric, etc.).

[0126] Of course, the second bottom surface 102 can also be pre-coated with adhesive. For example, in one embodiment, such as Figure 6As shown, the folding component 1221 is configured as a guide plate extending along the production direction. The guide plate has a guide surface 12210 that extends in a curved manner relative to the horizontal direction. The curved design can provide a continuous and smooth guide for the second bottom parting surface 102. During the movement of the bag unit along the production direction, the second bottom parting surface 102 will naturally change direction gradually along the shape of the curved guide surface to achieve bending.

[0127] Furthermore, the included angle between the guide surface 12210 and the conveying plane of the second conveying section 132 is along the production direction ( Figure 6 The angle gradually decreases (as indicated by the arrow in the image); the sealing component 1222 is configured as a sealing pressure roller. This ensures that the guiding force on the second bottom parting surface 102 is relatively gentle when it begins to bend, preventing excessive stress concentration due to sudden angle changes, which could lead to wrinkles or damage to the second bottom parting surface 102. As the bag unit moves, the included angle gradually decreases, and the guiding force gradually increases, which can more effectively push the second bottom parting surface 102 to complete the bending action, making the bending process of the second bottom parting surface 102 more stable. Moreover, the curved guide surface is relatively smooth, which can reduce the frictional resistance between the second bottom parting surface 102 and the guide plate during the folding process. Compared with a guide structure with right angles or sharp edges, the curved design can prevent the second bottom parting surface 102 from being scratched or stuck during bending, allowing the second bottom parting surface 102 to bend more smoothly along the guide surface. By setting the sealing component 1222 as a sealing pressure roller, the sealing pressure roller and the second bottom parting surface 102 are in rolling contact. The sealing pressure roller can apply uniform pressure to the second bottom parting surface 102 during rotation, so that the second bottom parting surface 102 has a better sealing effect.

[0128] Furthermore, based on the above structure, the second bottom sealing mechanism 120, for the packaging bag 10 sealed with glue on the second bottom parting surface 102, also includes a glue spraying component 123 and an air blowing component 124.

[0129] Specifically, the glue spraying component 123, the air blowing component 124, the folding component 1221, and the sealing component 1222 are arranged sequentially on the frame 140 along the production direction.

[0130] The structure of the adhesive spraying component 123 is not limited; for example, it can be configured as a pneumatic glue gun, an electric glue gun, etc. Specifically, the adhesive spraying component 123 is positioned at a location corresponding to the inner surface of the second bottom parting surface 102, and sprays adhesive onto the area where the second bottom parting surface 102 overlaps and is fixed with the intermediate support portion 103 and the first bottom parting surface 101. By providing the adhesive spraying component 123, the adhesive spraying component 123 will spray adhesive onto the inner surface of the second bottom parting surface 102 during operation. This spraying method will allow the adhesive to be more evenly coated on the inner surface of the second bottom parting surface 102, which is beneficial for better subsequent bonding of the second bottom parting surface 102.

[0131] The structure of the air blowing component 124 is not limited; it can be an air nozzle connected to an external air pump or an electric air blowing nozzle with its own air pump. Specifically, the air blowing component 124 is disposed on one side of the second bottom parting surface 102 and blows air toward the corresponding surface of the second bottom parting surface 102, so that the second bottom parting surface 102 smoothly enters the folding component 1221. Using the air blowing component 124, even if the second bottom parting surface 102 is tightly attached to the surface of the second conveying part 132 due to factors such as increased weight after being coated with adhesive, this application, by setting the air blowing component 124 before the folding component 1221, can not only separate the second bottom parting surface 102 from the surface of the second conveying part 132, but also open the second bottom parting surface 102 at a certain angle before it is folded by the folding component 1221, thus ensuring the stability of the second bottom parting surface 102 during smooth bending.

[0132] In summary, when sealing the bottom of the bag unit using the bottom sealing device 100 provided in this embodiment, not only can a more aesthetically pleasing packaging bag 10 be produced while ensuring the production efficiency of the manufacturing equipment, but it is also easier to adapt to other structures of the manufacturing equipment, especially when modifying old models of equipment, and the modification cost is lower.

[0133] Example 2:

[0134] This embodiment provides a packaging bag manufacturing device, such as... Figure 7 As shown, the device includes, in sequence along the production direction: a base material supply device (not shown), a tube forming device 200, a sealing device 300, a bottom sealing device 100 as in Example 1, a waste discharge device 400, and a collection device (not shown).

[0135] Specifically, the structure of the base material supply device is not limited, and may include, for example, a base material reel, a tension controller, and conveyor rollers. The base material reel is used to store sheet-like base material, the tension control device is used to maintain a stable tension in the base material, and the conveyor rollers are used to guide the sheet-like base material to the next station. In use, the base material is unwound from the base material reel, and after the tension is adjusted by the tension controller, it is guided by the conveyor rollers to the forming device 200.

[0136] The structure of the forming device 200 is not limited. For example, it may include a support template, a glue spraying unit and a pressure roller set on the frame 140. The glue spraying unit is set upstream of the support template. Before the sheet material is conveyed to the support template, the glue spraying unit sprays glue on the side of the sheet material. The pressure roller is set between the glue spraying unit and the support template to squeeze and seal the side of the material entering the support template. When the sheet material is conveyed to the support template, it wraps around the support template to form a cylindrical structure.

[0137] The sealing device 300 may include a drum body, on which a cutting mechanism and a bottom opening mechanism are arranged sequentially along the production direction.

[0138] The structure of the cutting mechanism is not limited, for example, it includes a cutting blade and a drive motor. As the base material of the cylindrical structure is gradually conveyed, the drive motor drives the cutting blade to reciprocate, cutting the cylindrical structure received by the sealing device 300 into individual bag units.

[0139] The structure of the bottom opening mechanism is not limited, for example, it includes a clamp. When the individual bag units are gradually conveyed on the drum, the clamp clamps the bottom corner of the individual bag units and moves relative to the drum, causing the bottom wall of the individual bag units to bend toward one side of the bag units, forming an intermediate support 103 and a first bottom parting surface 101 and a second bottom parting surface 102 located on both sides of the intermediate support 103.

[0140] The first bottom sealing mechanism 110 is disposed on the drum body and located downstream of the bottom opening assembly along the production direction, and is used to seal the first bottom split surface 101 and the second bottom split surface 102 to the intermediate support part 103 respectively.

[0141] The structure of the waste removal device 400 is not limited, and it is used to inspect and reject defective products from the bags sealed by the second bottom sealing mechanism 120. For example, the waste removal device 400 may include a detector and a rejection structure. The detector is used to detect the quality of the packaging bag 10, such as whether the bottom seal is firm and whether the size is accurate. The rejection structure is used to remove the detected defective products from the production line. In use, the packaging bag 10 after being processed by the bottom sealing device 100 is conveyed to the waste removal device 400. The detector performs quality inspection on the packaging bag 10, and if defective products are found, the rejection structure removes the defective products from the production line to ensure that only qualified products enter the next process.

[0142] The structure of the collection device is not limited, and it is used to collect qualified packaging bags 10 that have not been rejected by the waste discharge device 400. For example, it may include a collection box and a conveyor device. The collection box is used to store qualified products, and the conveyor device is used to transport qualified products from the production line to the collection box. In use, qualified products that have passed the waste discharge device 400 are transported to the collection device. The conveyor device transports the qualified products into the collection box, completing the entire production process of the packaging bag 10.

[0143] The packaging bag manufacturing equipment provided in this embodiment includes the bottom sealing device 100 with the above-described structure. When manufacturing the packaging bag 10, the first bottom sealing mechanism 110 located on the drum body only seals the first bottom parting surface 101. When the second bottom sealing mechanism 120 seals the second bottom parting surface 102, the second bottom sealing mechanism 120 includes a limiting component 121 mounted on the frame 140 and a guiding sealing component 122 mounted on one side of the limiting component 121. The first bottom sealing mechanism 101 has an abutment surface extending along the production direction. When the bag unit passes the second bottom sealing mechanism 120, the abutment surface presses against the intermediate support portion 103 of the bag unit, and one edge aligns with the bend line of the second bottom parting surface 102 relative to the intermediate support portion 103. As the bag unit gradually moves along the production direction, the guide sealing component 122 guides the second bottom parting surface 102 to bend relative to the intermediate support portion 103 and overlap and fix it onto the intermediate support portion 103 and the first bottom parting surface 101. Throughout the process, the various structures in the second bottom sealing mechanism 120 do not create indentations or other marks on the sidewall of the bag unit corresponding to the second bottom parting surface 102, resulting in a more aesthetically pleasing final packaging bag 10.

[0144] Example 3:

[0145] This application also provides a method for manufacturing a packaging bag, such as... Figure 8 As shown, this method can be applied to the manufacturing equipment in Example 2 and includes the following steps:

[0146] S1. Form the sheet material into a continuous cylindrical structure;

[0147] S2. Cut the continuous cylindrical structure into individual bag units 104 (see...) Figure 10 (as shown in the image);

[0148] S3. Bend the bottom wall of each individual bag unit toward one side of the bag unit (see...). Figure 11 (as shown in the image);

[0149] S4. Convey the bag unit along the production direction with the length direction of the bag unit coinciding with the production direction.

[0150] S5. Seal the first bottom part 101 of the bottom wall to the middle support part 103 of the bottom wall (see Figure 12 (as shown in the image);

[0151] S6. Change the orientation of the bag unit so that the length direction of the bag unit is perpendicular to the production direction;

[0152] S7. Seal the second bottom part 102 of the bottom wall to the middle support part 103 of the bottom wall (see...) Figure 9 (The state shown).

[0153] The manufacturing method provided in this embodiment, when sealing the bottom of the bag unit, first seals the first bottom parting surface 101 with the length direction of the bag unit coinciding with the production direction. After the first bottom parting surface 101 is sealed, the orientation of the bag unit is changed so that the length direction of the bag unit is perpendicular to the production direction. Then, the second bottom parting surface 102 of the bottom wall is sealed to the middle support part 103 of the bottom wall. In this process, the first bottom parting surface 101 and the second bottom parting surface 102 of the bag unit are sealed in two steps, and the bag unit is switched to different orientations in the two steps. In this way, based on the structural characteristics of the first bottom parting surface 101 and the second bottom parting surface 102, sealing mechanisms adapted to them can be set in two sealing stations. This not only helps to eliminate the indentation on the side wall of the bag unit corresponding to the second bottom parting surface 102, but also does not require major matching improvements to other structures when applied to various packaging bag manufacturing equipment. This can achieve the overall cooperation between this sealing device 100 and the manufacturing equipment, and has the advantage of good applicability. Furthermore, the two sealing mechanisms can be set independently, and their sealing action will not affect the conveying of the bag unit. The packaging bag 10 does not need to stop between the two sealing stations, which can ensure the continuous processing of the bag unit.

[0154] Furthermore, before sealing the second bottom part 102 of the bottom wall to the middle support portion 103 of the bottom wall, the method further includes aligning the bending line of the second bottom part 102 in the bag unit with the edge of the abutting surface of the limiting component 121 in the second bottom sealing mechanism 120.

[0155] Using this method, even if there is a deviation between the bag unit and the conveying path of the second conveying section 132 after the bag unit rotates, this application can ensure the success rate of sealing the second bottom parting surface 102 and improve the aesthetics of sealing by aligning the bending line of the second bottom parting surface 102 with the edge of the contact surface of the limiting component 121 in the second bottom sealing mechanism 120.

[0156] Example 4:

[0157] like Figures 9 to 12As shown, this embodiment provides a packaging bag 10, which is manufactured using the manufacturing method of Embodiment 3. The packaging bag 10 includes a bag body with a cavity. The bag body includes a pair of front walls disposed opposite each other in the thickness direction of the bag body, a pair of side walls disposed opposite each other in the width direction of the bag body, and a bottom wall disposed at the bottom of the bag body along the height direction of the bag body. The pair of front walls and the pair of side walls surround the top of the bag body to form a bag opening. The bottom wall includes a central support portion 103 and first bottom walls located on both sides of the central support portion 103 along the thickness direction of the packaging bag 10. The first bottom part 101 and the second bottom part 102 are bent inward relative to the side wall of the packaging bag 10. The first bottom part 101 and the second bottom part 102 are bent toward the middle support 103 and fixed to the corresponding surface of the middle support 103. The opposite ends of the first bottom part 101 and the second bottom part 102 overlap and are fixed to each other. In addition, the outer wall surface of one of the two front walls is a smooth plane, and a bending line is formed on the other front wall near the bottom surface. The other front wall is a smooth plane from the bending line to the bag opening.

[0158] The packaging bag 10 provided in this embodiment is made using the above method. Since there are no indentations on the side wall of the packaging bag 10 corresponding to the second bottom parting surface 102, it is not only aesthetically pleasing, but also less prone to bending or tipping over due to indentations when unfolded. It has better stability and makes it easier for users to put items into the bag, thus improving the user experience.

[0159] It should be noted that, in addition to the specific embodiments described above, those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details are included in the above description, and the invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0160] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0161] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0162] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0163] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0164] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A bottom-sealing device for a packaging bag, comprising sealing a cylindrical bag unit to form the bottom wall of the packaging bag, the bottom wall of the packaging bag including a central support portion, a first bottom parting surface and a second bottom parting surface located on both sides of the central support portion along the thickness direction of the packaging bag; wherein, The intermediate support portion is bent inward relative to the side wall of the packaging bag, the first bottom parting surface and the second bottom parting surface are respectively bent toward the intermediate support portion and fixed to the corresponding surface of the intermediate support portion, and the opposite ends of the first bottom parting surface and the second bottom parting surface overlap and are fixed to each other; characterized in that the bottom sealing device includes: frame; A first bottom sealing mechanism is disposed on the frame and is used to seal the first bottom parting surface to the bottom surface. The first bottom parting surface is the bottom parting surface of the bottom wall that is closer to the middle support part. A second bottom sealing mechanism, mounted on the frame and located downstream of the first bottom sealing mechanism along the production direction of the packaging bag, is used to seal the second bottom parting surface to the bottom surface, with the end of the second bottom parting surface overlapping and fixed to the end of the first bottom parting surface; wherein The second bottom sealing mechanism includes a limiting component disposed on the frame and a guiding sealing component disposed on one side of the limiting component. The limiting component has an abutment surface extending along the production direction. When the bag unit passes through the second bottom sealing mechanism, the abutment surface presses against the intermediate support portion of the bag unit, and one edge aligns with the bending line of the second bottom parting surface relative to the intermediate support portion. The guiding sealing component guides the second bottom parting surface to bend relative to the intermediate support portion and overlap and fix it to the intermediate support portion and the first bottom parting surface. The bottom sealing device also includes a bag conveying device disposed on the frame and extending from the inlet of the first bottom sealing mechanism to the outlet of the second bottom sealing mechanism. The bag conveying device includes a first conveying section extending through the first bottom sealing mechanism, a second conveying section extending through the second bottom sealing mechanism, and a reversing mechanism disposed between the first conveying section and the second conveying section; wherein... The first conveying section conveys the bag unit along the production direction with its length direction coinciding with the production direction, passing it through the first bottom sealing mechanism. The first bottom sealing mechanism seals the first bottom part with the bag unit's length direction coinciding with the production direction. The reversing mechanism changes the orientation of the bag unit from the first conveying section so that the bag unit's length direction is perpendicular to the production direction and conveys the bag unit to the second conveying section. The second conveying section receives the reversed bag unit and conveys it along the production direction through the second bottom sealing mechanism, so that the folding action of the second bottom part is perpendicular to the production direction.

2. The sealing device for the packaging bag as described in claim 1, characterized in that, The limiting component includes a limiting plate extending along the production direction, and one side of the limiting plate has the abutment surface extending in the horizontal direction. The guide sealing assembly includes a folding component and a sealing component; wherein, the folding component is disposed on the other side of the limiting plate perpendicular to the production direction relative to the bending line, and bends the second bottom parting surface along the bending line, and the sealing component fixes the second bottom parting surface to the bottom surface.

3. The sealing device for the packaging bag as described in claim 2, characterized in that, The folding component is configured as a guide plate extending along the production direction. The guide plate has a guide surface that extends in a curved manner relative to the horizontal direction, and the angle between the guide surface and the conveying plane of the second conveying section gradually decreases along the production direction. The sealing component is configured as a sealing pressure roller.

4. The sealing device for the packaging bag as described in claim 2, characterized in that, The second sealing mechanism also includes a glue spraying component and an air blowing component; wherein, The glue spraying component, the air blowing component, the folding component, and the sealing component are sequentially arranged on the frame along the production direction; wherein... The adhesive spraying component is positioned at a location corresponding to the inner surface of the second bottom parting surface, and sprays adhesive onto the portion of the second bottom parting surface that overlaps and is fixed to the intermediate support and the first bottom parting surface; and The air blowing component is disposed on one side of the second bottom parting surface and blows air toward the corresponding surface of the second bottom parting surface, so that the second bottom parting surface smoothly enters the folding component.

5. The sealing device for the packaging bag as described in claim 1, characterized in that, The bag conveying device further includes an alignment adjustment mechanism disposed on the frame and located between the reversing mechanism and the limiting component. The alignment adjustment mechanism drives the bag unit reversed by the reversing mechanism to move in a direction perpendicular to the production direction, so that the bending line of the second bottom parting surface is aligned with one edge of the abutting surface.

6. The sealing device for a packaging bag as described in claim 5, characterized in that, Both the first conveying section and the second conveying section include conveyor belts extending along the production direction, and at least the conveyor belt of the second conveying section has a gap extending along the production direction. The alignment adjustment mechanism includes a limiting baffle, an adjusting wheel, and a pressing limiting component; wherein, The limiting baffle extends along the production direction and is adjustablely positioned on the frame, located on the side corresponding to the bottom wall of the packaging bag; The adjusting wheel is rotatably mounted on the frame about the production direction and at least partially protrudes into the gap of the second conveying section in the vertical direction; The pressing and limiting component is vertically and vertically connected to the frame and located above the adjusting wheel.

7. The sealing device for a packaging bag as described in any one of claims 1 to 6, characterized in that, The reversing mechanism includes a corner blocking member, which is disposed at the inlet of the second conveying section, corresponding to the corner of the bottom wall of the packaging bag near the limiting component; wherein, The bottom wall of the bag unit, which passes through the entrance of the second conveying section from the first conveying section, abuts against the corner blocking member at the corner of the limiting component. The bag unit rotates around the corner blocking member to change to an orientation perpendicular to the production direction.

8. The sealing device for a packaging bag as described in claim 7, characterized in that, The corner blocking member is configured as an inverted conical blocking rod; and the reversing mechanism further includes a transfer component, which is vertically and flexibly mounted on the frame, located on one side of the corner blocking member, and closer to the middle position of the inlet of the second conveying section in a direction perpendicular to the production direction; wherein, When one corner of the bottom wall of the bag unit abuts against the corner blocking member, the transfer component presses down on the bottom wall of the bag unit and rotates, causing the bag unit to rotate around the corner blocking member.

9. The sealing device for a packaging bag as described in claim 8, characterized in that, The reversing mechanism further includes an extrusion conveyor wheel disposed upstream of the transfer component in the production direction. The extrusion conveyor wheel is rotatably connected to the frame. The transfer component includes a lifting member disposed on the frame and an extrusion rotating head rotatably connected to the lifting end of the lifting member. The extrusion conveyor wheel rotates along the production direction to transport the bag unit toward the transfer component. The lifting component, in conjunction with the extrusion rotating head, presses against the bottom wall of the bag unit, and the extrusion rotating head rotates synchronously with the bag unit.

10. The sealing device for a packaging bag as described in claim 9, characterized in that, The extrusion conveyor wheel has an arc-shaped extrusion surface and an avoidance notch formed sequentially along its circumference, and the arc length of the arc-shaped extrusion surface is less than the length of the bag unit.

11. The sealing device for a packaging bag as described in any one of claims 1 to 6, characterized in that, The first sealing mechanism includes a rotating shaft rotatably connected to the frame, a pressure knife and a sealing wheel sequentially arranged on the rotating shaft along its circumference; wherein, The rotation of the rotating shaft sequentially links the pressing knife to the bending line of the first bottom parting surface and the sealing wheel to roll on the first bottom parting surface.

12. A packaging bag manufacturing device, characterized in that, Including those arranged sequentially along the production direction: A base material supply device for conveying sheet-like base material to the next work station; A cylindrical forming device, wherein the cylindrical forming device receives the base material supplied by the base material supply device and forms the base material into a continuous cylindrical structure; A sealing device, comprising a large drum body, on which a cutting mechanism and a bottom-opening mechanism are sequentially arranged along the production direction; the cutting mechanism is used to cut the cylindrical structure received by the sealing device into individual bag units, and the bottom-opening mechanism is used to bend the bottom wall of the individual bag units toward one side of the bag units to form an intermediate support portion, a first bottom parting surface and a second bottom parting surface located on both sides of the intermediate support portion; The bottom sealing device as described in any one of claims 1 to 11, wherein the first bottom sealing mechanism is disposed on the drum body and located downstream of the bottom opening assembly along the production direction, for sealing the first bottom parting surface and the second bottom parting surface to the intermediate support portion respectively; Waste discharge device, which is used to detect and remove waste products from the bag after it is sealed by the second bottom sealing mechanism; A collection device for collecting qualified packaging bags that have not been rejected by the waste discharge device.

13. A method for manufacturing a packaging bag, characterized in that, The apparatus for manufacturing the packaging bag as described in claim 12 includes the following steps: The sheet-like base material is molded into a continuous cylindrical structure; The continuous cylindrical structure is cut into individual bag units; The bottom wall of each individual bag unit is bent toward one side of the bag unit; The bag unit is transported along the production direction with its length direction coinciding with the production direction. The first bottom part of the bottom wall is sealed to the middle support part of the bottom wall; The orientation of the bag unit is transformed so that the length direction of the bag unit is perpendicular to the production direction; The second bottom part of the bottom wall is sealed to the middle support part of the bottom wall.

14. The method for manufacturing a packaging bag as described in claim 13, characterized in that, Before sealing the second bottom part of the bottom wall to the intermediate support part of the bottom wall, it also includes: Align the bending line of the second bottom parting surface in the bag unit with the edge of the abutting surface of the limiting component in the second bottom sealing mechanism.

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