A heat-sealing structure of a plastic packaging bag and a method of use

Abstract

The application relates to the technical field of packaging bag sealing, in particular to a plastic packaging bag heat sealing structure and a use method, which comprise a conveying mechanism, limit plates are symmetrically arranged on the top surface of the conveying mechanism, the front and back ends of the limit plates are in arc shapes, the interval of the two limit plates is matched with the width of a paper box to be transported, two limit frames are further arranged above the conveying mechanism and between the two limit plates, the two limit frames are symmetrically distributed, the height of the limit frame is higher than the height of the paper box and lower than the top end height of the packaging bag; the application has a negative pressure suction assembly and a suction mechanism, the negative pressure suction assembly is used for opening the bag mouth, the suction mechanism is used for sucking the air in the plastic packaging bag, and then a hot pressing head is used for pressing and sealing the plastic bag; compared with the traditional technology, the artificial participation degree of the application is greatly reduced, which helps to reduce the labor intensity and improve the production efficiency.

Description

Technical Field

[0001] This invention relates to the field of packaging bag sealing technology, specifically to a heat-sealing structure and method for using a plastic packaging bag. Background Technology

[0002] Thermo-sealing of plastic bags is a common sealing method. The principle of thermo-sealing of plastic bags is mainly based on the thermoplastic properties of plastics. When the plastic bag is heated, its material (such as polyethylene or polypropylene) softens, making the originally solid plastic fluid. At this time, by applying pressure, the two edges of the plastic bag can be tightly sealed together.

[0003] Currently, heat sealing of plastic packaging bags requires a heat sealing machine. The main components of a heat sealing machine are two heat sealing heads. When heat sealing is required, the opening of the plastic packaging bag is placed between the two heat sealing heads, and then the corresponding switch on the heat sealing machine is activated, causing the two heat sealing heads to clamp the bag opening tightly. After a few seconds, they are released to complete the heat sealing. Furthermore, in existing technology, because plastic bags are inherently soft, they are generally used as inner packaging, while outer packaging often uses cardboard boxes or other rigid materials.

[0004] Currently, before heat-sealing the plastic bags inside a cardboard box, the materials must first be packed into the plastic bags. The cardboard box and plastic bags are then transported together to a heat-sealing machine. At this point, workers need to press the plastic bags to expel excess air; otherwise, if there is too much air inside the plastic bags after sealing, the box lid may not close properly. Then, the bag opening is placed between two heat-sealing heads for heat sealing. This heat-sealing process involves a high degree of manual intervention, thus reducing its efficiency. Therefore, we propose a heat-sealing structure and method for plastic bags to effectively address these shortcomings. Summary of the Invention

[0005] The purpose of this invention is to provide a heat-sealing structure and method for using plastic packaging bags, in order to solve the problems mentioned in the background art.

[0006] This invention is achieved through the following technical solution:

[0007] A heat-sealing structure for a plastic packaging bag includes: a conveying mechanism, wherein limiting plates are symmetrically arranged on the left and right sides of the top surface of the conveying mechanism, the front and rear ends of the limiting plates are arc-shaped, and the distance between the two limiting plates is adapted to the width of the carton being transported; two limiting frames are also arranged above the conveying mechanism and between the two limiting plates, the two limiting frames are symmetrically distributed from left to right, and the height of the limiting frames is higher than the height of the carton and lower than the top height of the packaging bag; and columns are provided at both the front and rear ends of the limiting frames, the columns being fixedly connected to the conveying mechanism.

[0008] The movable part corresponds one-to-one with the limiting frame. The movable part is slidably connected to the corresponding limiting frame. The length of the movable part is adapted to the length of the carton. Negative pressure suction components are provided on the facing surfaces of the two movable parts to attract the top of the packaging bag and open its opening. Sponge squeezing components are also provided on the facing surfaces of the two movable parts. The two sponge squeezing components are used to squeeze each other to close the opening of the packaging bag.

[0009] A suction mechanism is located directly above the two movable parts. The suction mechanism is used to extend into the packaging bag and extract the air from the packaging bag.

[0010] A negative pressure source, which is connected to the negative pressure suction component and the suction mechanism, is used to provide negative pressure to the negative pressure suction component and the suction mechanism;

[0011] The two moving parts are provided with embedded grooves on their facing surfaces, and electric push rods are provided on their facing back surfaces. Hot press heads are movably provided in both embedded grooves, and the movable ends of the two electric push rods extend into the embedded grooves and are fixedly connected to the corresponding hot press heads.

[0012] Optionally, the moving part has a through hole, the limiting frame is inserted into the through hole, and the opposite sides of the two limiting frames are provided with linear slides, the movable end of the linear slides is fixedly connected to the inner wall of the through hole.

[0013] Optionally, each of the two moving parts has a suction cavity on its top facing surface, and each of the two moving parts has a suction head communicating with the suction cavity on its top facing back surface. The negative pressure suction assembly includes a sealing cover plate and a plurality of suction cups disposed on the sealing cover plate. The sealing cover plate covers the inside of the suction cavity, the suction cups communicate with the suction cavity, and the suction head is connected to the negative pressure source through a first flexible hose. A first solenoid valve is disposed on the first flexible hose.

[0014] Optionally, the conveying mechanism is further provided with a ranging sensor and a controller. When the moving part is located at the starting end, the ranging sensor is flush with the rear end of the moving part. The signal output terminal of the ranging sensor is connected to the controller, and the signal output terminal of the controller is connected to the linear slide, the first solenoid valve, and the electric push rod.

[0015] Optionally, each of the two moving parts has an extrusion groove on its bottom facing surface. The sponge extrusion assembly includes an extrusion plate, a sponge block, and a push rod. The extrusion plate is movably disposed in the corresponding extrusion groove, the sponge block is disposed on the facing surface of the two extrusion plates, and the push rod is disposed on the back surface of the two extrusion plates.

[0016] Optionally, the end of the push rod facing away from the extrusion plate passes through the back of the moving part and is provided with a rolling wheel. The top facing surfaces of the two limiting plates are provided with extrusion tracks. A limiting spring is connected between the extrusion plate and the inner wall of the extrusion groove. In the natural state, the limiting spring is in a stretched state, and the rolling wheel abuts against the inner surface of the limiting plate. When the moving part moves to the area between the two extrusion tracks, the rolling wheel rolls and fits against the extrusion tracks, and the two sponge blocks fit against each other.

[0017] Optionally, the suction mechanism includes a lifting part, the interior of which is provided with a negative pressure cavity. The bottom surface of the lifting part is provided with a flat suction part, which communicates with the negative pressure cavity. The top surface of the lifting part is also provided with an air nozzle that communicates with the negative pressure cavity. The air nozzle is connected to the negative pressure source through a second hose, and a second solenoid valve is also provided on the second hose.

[0018] Optionally, guide rods are vertically provided at the four corners of the bottom surface of the lifting unit, and extension blocks are provided on the opposite sides of the two moving parts. The guide rods movably pass through the corresponding extension blocks. Tracks are provided on the opposite sides of the two limiting plates. Vertical rods are symmetrically provided on the left and right sides of the bottom surface of the lifting unit. Rollers are provided at the bottom of the vertical rods. The rollers are movably inserted into the track. The track is a five-segment structure consisting of a first horizontal segment, a descending segment, a second horizontal segment, an ascending segment, and a third horizontal segment. When the rollers are located inside the first and third horizontal segments, the suction part is located above the moving parts. When the rollers are located inside the second horizontal segment, the suction part extends between the two moving parts, and the bottom end of the suction part is lower than the moving parts.

[0019] Optionally, the conveying mechanism is provided with a power source outside, and conductive strips are provided inside the second horizontal section. The two conductive strips are respectively connected to the positive and negative terminals of the power source. The rollers are made of copper pillars. The two leads of the second solenoid valve are respectively connected to the two rollers. When the rollers enter the interior of the second horizontal section, the second solenoid valve opens.

[0020] This invention also proposes a method for using a heat-sealing structure for plastic packaging bags, applicable to the aforementioned heat-sealing structure for plastic packaging bags, comprising the following steps:

[0021] The cardboard box and its internal plastic packaging bag are placed together at the starting end of the conveyor mechanism. Then, the staff pinches the opening of the plastic packaging bag and lifts it upwards so that the opening of the plastic packaging bag can smoothly enter between the two moving parts.

[0022] Under the action of the two limiting plates, the length direction of the carton can be kept consistent with the length direction of the conveying mechanism. When the front end of the carton moves to be flush with the distance sensor, the controller immediately starts the linear slide and the first solenoid valve.

[0023] The linear slide is used to drive the moving part to move, and the moving speed of the moving part is consistent with the forward speed of the carton. After the first solenoid valve is opened, the negative pressure suction component is used to attract the top of the packaging bag to open its mouth.

[0024] The sponge compression assembly is then used to press the opening of the packaging bag tightly, and the suction mechanism is used to remove the air from inside the packaging bag. Finally, two hot press heads are pressed together to seal the opening of the packaging bag.

[0025] Compared with the prior art, the present invention provides a heat-sealing structure and method for using a plastic packaging bag, which has the following beneficial effects:

[0026] 1. The present invention has a negative pressure suction component and a suction mechanism. The negative pressure suction component is used to open the bag opening, and the suction mechanism is used to suck the air inside the plastic packaging bag. Then, the plastic bag is sealed by pressing with a hot press head. Compared with traditional technology, the present invention greatly reduces the degree of manual intervention, which not only helps to reduce the intensity of manual labor, but also helps to improve production efficiency.

[0027] 2. The moving part in this invention can move synchronously with the conveying mechanism, and when the carton is completely under the moving part, it can be detected by the distance sensor. At this time, the moving part can be started immediately, thereby ensuring that the opening of the plastic bag can move synchronously with the carton. Therefore, it helps to improve the automation level of this invention.

[0028] 3. The present invention has a sponge extrusion assembly. When the moving part moves between the two extrusion tracks, the two sponge blocks can approach each other and press the bag opening, which helps the suction mechanism to extract the air inside the packaging bag cleanly.

[0029] 4. The suction mechanism in this invention can automatically complete the descent, suction, and ascent steps as the moving part moves, thus contributing to further automation of this invention. Attached Figure Description

[0030] Figure 1 A schematic diagram of cardboard boxes and plastic packaging bags;

[0031] Figure 2 This is a schematic diagram of the structure of the present invention;

[0032] Figure 3 This is a top view of the structure of the present invention;

[0033] Figure 4 This is a cross-sectional view of the structure of the present invention;

[0034] Figure 5 This is a side view of the structure of the present invention;

[0035] Figure 6 This is a schematic diagram of the moving part structure of the present invention;

[0036] Figure 7 This is a schematic diagram of the moving part of the present invention from another angle;

[0037] Figure 8 This is a cross-sectional view of the moving part structure of the present invention;

[0038] Figure 9 This is a schematic diagram of the limiting frame structure of the present invention;

[0039] Figure 10 This is a schematic diagram of the suction mechanism of the present invention;

[0040] Figure 11 This is a schematic diagram of the movement track structure of the present invention;

[0041] Figure 12 This is a schematic diagram of the negative pressure suction system of the present invention.

[0042] In the diagram: 100, Conveying mechanism; 101, Limiting plate; 102, Limiting frame; 103, Column; 104, Extrusion track; 105, Electric push rod; 106, Hot press head; 107, Traveling track; 1071, First horizontal section; 1072, Descending section; 1073, Second horizontal section; 1074, Ascending section; 1075, Third horizontal section; 200, Moving part; 201, Penetrating hole; 202, Suction chamber; 203, Suction head; 204, Sealing cover plate; 205, Suction cup; 206, Extrusion groove; 207, Extrusion plate; 208, Sponge block ; 209. Push rod; 210. Rolling wheel; 211. Extension block; 212. Limiting spring; 213. Embedded groove; 300. Linear slide; 400. Negative pressure source; 401. First hose; 402. First solenoid valve; 403. Second hose; 404. Second solenoid valve; 500. Suction mechanism; 501. Lifting part; 502. Negative pressure cavity; 503. Suction part; 504. Air nozzle; 505. Guide rod; 506. Vertical rod; 507. Roller; 600. Power supply; 601. Conductive strip; 700. Distance sensor; 800. Controller. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Please see Figure 1 , Figure 1 The diagram shows a cardboard box and a plastic packaging bag. Before the plastic packaging bag is heat-sealed, the material needs to be put into the bag first. Then the cardboard box and the packaging bag are transported together to the heat sealing machine. At this time, the operator needs to press the packaging bag to expel the gas inside. Then the bag opening is straightened and lifted upwards so that the bag opening enters between two heat sealing heads. Finally, the corresponding switch on the heat sealing machine is turned on, and the two heat sealing heads are used to press and seal the bag opening.

[0045] However, the above steps involve a high degree of manual intervention, which reduces work efficiency. Specifically, manually pressing the plastic packaging bag to expel the internal gas is quite cumbersome. In addition, since the plastic packaging bag is pressed down into the cardboard box, when lifting the bag opening, it is necessary to first locate the bag opening, then pinch the two corners of the bag opening with both hands, and finally straighten the bag opening and lift it upwards. This step is also quite cumbersome. In summary, the efficiency of heat sealing needs to be improved.

[0046] To address the above problems, the present invention proposes the following technical solution:

[0047] Example 1: Please refer to Figure 2 - Figure 12 A heat-sealing structure for a plastic packaging bag includes a conveying mechanism 100, which is a roller conveyor. The top surface of the conveying mechanism 100 has symmetrically arranged limiting plates 101 on both sides. The length direction of the limiting plates 101 is consistent with the length direction of the conveying mechanism 100, and the front and rear ends of the limiting plates 101 are arc-shaped. The distance between the two limiting plates 101 is adapted to the width of the carton being transported, that is, the distance between the two limiting plates 101 is slightly greater than the width of the carton, allowing the carton to smoothly enter between the two limiting plates 101. Above the conveying mechanism 100 and located between the two limiting plates 101, two limiting frames 102 are also provided. The two limiting frames 102 are symmetrically distributed left and right, and the height of the limiting frames 102 is higher than the height of the carton but lower than the top height of the packaging bag. The bottom front and rear ends of the limiting frames 102 are provided with columns 103, which are fixedly connected to the conveying mechanism 100.

[0048] Furthermore, each of the two limiting frames 102 is slidably connected to a movable part 200. The length of the movable part 200 is adapted to the length of the carton. A through hole 201 is provided inside the movable part 200, and the limiting frame 102 is inserted into the through hole 201. A linear slide 300 is provided on the opposite sides of both limiting frames 102. Figure 9 As shown, the length direction of the linear slide 300 is consistent with the length direction of the limit frame 102, and the movable end of the linear slide 300 is fixedly connected to the inner wall of the through hole 201; therefore, the linear slide 300 can control the forward and backward translation of the moving part 200.

[0049] Furthermore, both moving parts 200 have negative pressure suction components on their opposing surfaces to attract the top of the packaging bag and open its opening; specifically, both moving parts 200 have suction chambers 202 on their opposing top surfaces, such as... Figure 8 As shown, both movable parts 200 have suction heads 203 that communicate with the suction chamber 202 on their top and back sides. The negative pressure suction assembly includes a sealing cover plate 204 and a plurality of suction cups 205 disposed on the sealing cover plate 204. The sealing cover plate 204 covers the inside of the suction chamber 202. The suction cups 205 communicate with the suction chamber 202. Therefore, when the inside of the suction chamber 202 is in a negative pressure state, the suction cups 205 can generate negative pressure and attract the bag opening of the packaging bag.

[0050] This embodiment also includes a negative pressure source 400, which is connected to a negative pressure suction assembly. Specifically, the negative pressure source 400 can be a fan, and the suction head 203 is connected to the negative pressure source 400 through a first flexible hose 401. A first solenoid valve 402 is provided on the first flexible hose 401. Therefore, when the first solenoid valve 402 is opened, the negative pressure source 400 can generate negative pressure inside the suction chamber 202.

[0051] Furthermore, the two moving parts 200 are also provided with sponge compression assemblies on their facing surfaces. The two sponge compression assemblies are used to compress each other to close the bag opening. Specifically, the bottom facing surfaces of the two moving parts 200 are each provided with compression grooves 206. The sponge compression assembly includes a compression plate 207, a sponge block 208, and a push rod 209. The compression plate 207 is movably disposed in the corresponding compression groove 206, the sponge block 208 is disposed on the facing surfaces of the two compression plates 207, and the push rod 209 is disposed on the facing back surfaces of the two compression plates 207. The end of the push rod 209 facing away from the compression plate 207 movably passes through the back of the moving part 200 and is provided with a rolling wheel 210. Both top facing surfaces of the two limiting plates 101 are provided with extrusion rails 104. A limiting spring 212 is connected between the extrusion plate 207 and the inner wall of the extrusion groove 206. In the natural state, the limiting spring 212 is in a stretched state, and the rolling wheel 210 abuts against the inner surface of the limiting plate 101. When the moving part 200 moves to the area between the two extrusion rails 104, the rolling wheel 210 rolls and fits against the extrusion rail 104, and the two sponge blocks 208 fit against each other. When the moving part 200 slides in the front-back direction, the rolling wheel 210 can roll along the limiting plate 101 or the extrusion rail 104, thereby controlling the two sponge blocks 208 to move closer or further away from each other.

[0052] It is worth mentioning that the front and rear ends of the extrusion track 104 are arc-shaped, such as... Figure 3 As shown, when the moving part 200 is at the starting position, the rolling wheel 210 rolls and adheres to the surface of the limiting plate 101; when the two sponge blocks 208 adhere to each other, the bag opening can be closed. In addition, the length of the sponge block 208 is not less than the length of the bag opening, that is, the sponge block 208 can completely close the bag opening.

[0053] In addition, the two moving parts 200 are provided with an inner groove 213 on their facing surfaces, and electric push rods 105 are provided on the back surfaces of the two moving parts 200. The inner groove 213 is located below the suction chamber 202. A hot pressing head 106 is movably installed in each of the two inner grooves 213. The movable ends of the two electric push rods 105 extend into the inner groove 213 and are fixedly connected to the corresponding hot pressing head 106. Therefore, the two electric push rods 105 can control the two hot pressing heads 106 to squeeze each other, thereby sealing the bag opening.

[0054] This embodiment also includes a suction mechanism 500, located directly above the two movable parts 200. The suction mechanism 500 is used to extend into the packaging bag and extract air from it. Specifically, the suction mechanism 500 includes a lifting part 501, and a negative pressure cavity 502 is formed inside the lifting part 501. Figure 4As shown, the bottom surface of the lifting part 501 is provided with a flat suction part 503, which communicates with the negative pressure cavity 502. The top surface of the lifting part 501 is also provided with an air nozzle 504 that communicates with the negative pressure cavity 502. The air nozzle 504 is connected to the negative pressure source 400 through a second hose 403. A second solenoid valve 405 is also provided on the second hose 403. Therefore, when the second solenoid valve 405 is opened, a negative pressure can be generated in the suction part 503, thereby using the suction part 503 to extract the air inside the packaging bag.

[0055] Furthermore, guide rods 505 are vertically provided at the four corners of the bottom surface of the lifting part 501, and extension blocks 211 are provided on the opposite sides of the two moving parts 200. The guide rods 505 can move through the corresponding extension blocks 211, that is, the lifting part 501 can rise and fall along the length of the guide rods 505. The opposite sides of the two limiting plates 101 are provided with a travel track 107. Vertical rods 506 are symmetrically provided on the left and right sides of the bottom surface of the lifting part 501. Rollers 507 are provided at the bottom of the vertical rods 506. The rollers 507 are cylindrical and fixedly connected to the vertical plates 506. The rollers 507 are movably inserted into the travel track 107. The travel track 107 consists of a first horizontal section 107. 1. The five-segment structure consisting of the descending segment 1072, the second horizontal segment 1073, the ascending segment 1074, and the third horizontal segment 1075, with the track 107 exhibiting an overall descending-then-ascending trend. When the roller 507 is located inside the first horizontal segment 1071 and the third horizontal segment 1075, the suction part 503 is located above the moving part 200. When the roller 507 is located inside the second horizontal segment 1073, the suction part 503 extends between the two moving parts 200, and the bottom of the suction part 503 is lower than the moving part 200. Specifically, when the roller 507 is located inside the second horizontal segment 1073, the suction part 503 can extend into the packaging bag for easy air extraction.

[0056] Furthermore, a power supply 600 is provided externally for the conveying mechanism 100, and a conductive strip 601 is provided inside the second horizontal section 1073, such as... Figure 11 As shown, the track 107 is made of insulating material, the conductive strip 601 is made of copper, and the two conductive strips 601 are respectively connected to the positive and negative terminals of the power supply 600. The roller 507 is made of copper, the vertical rod 506 is made of insulating material, and the two leads of the second solenoid valve 405 are respectively connected to the two rollers 507. When the roller 507 enters the second horizontal section 1073 and contacts the conductive strip 601, the second solenoid valve 405 opens, and at the same time the suction section 503 begins to suck the air inside the packaging bag.

[0057] It is worth mentioning that during the forward movement of the moving part 200, since the roller 507 can move along the track 107, the lifting part 501 can move down and then up. When the roller 507 just enters the second horizontal section 1073 from the lowering section 1072, the rolling wheel 210 has not yet come into contact with the extrusion track 104. When the rolling wheel 210 just moves from the limiting plate 101 to the extrusion track 104, the roller 507 is still located in the second horizontal section 1073 and in contact with the conductive strip 601. That is, the suction part 503 first extends into the packaging bag, and then the two sponge blocks 208 move closer to each other to press the bag opening, and at the same time press the suction part 503. The purpose is to prevent the suction part 503 from rubbing against the packaging bag during the downward movement, thereby damaging the packaging bag.

[0058] It should be noted that during the forward movement of the moving part 200, when the rolling wheel 210 moves from the limiting plate 101 to the extrusion track 104, the roller 507 has already moved into the second horizontal section 1073; when the rolling wheel 210 moves from the extrusion track 104 to the limiting plate 101, the roller 507 is still located in the third horizontal section 1075.

[0059] In addition, the conveying mechanism 100 is also equipped with a ranging sensor 700 and a controller 800. The ranging sensor 700 can be a laser ranging sensor, and the controller 800 is a Cortex-A53 processor. When the moving part 200 is at the starting end, the ranging sensor 700 is flush with the rear end of the moving part 200. The signal output terminal of the ranging sensor 700 is connected to the controller 800. The signal output terminal of the controller 800 is connected to the linear slide 300, the first solenoid valve 402, and the electric push rod 105. Since the length of the carton is similar to the length of the moving part 200, when the front end of the carton moves to be flush with the ranging sensor 700, the carton moves to the position directly below the moving part 200. At this time, the controller 800 can immediately start the linear slide 300 and open the first solenoid valve 402.

[0060] Example 2: This example proposes a method for using a heat-sealing structure for plastic packaging bags, applicable to the heat-sealing structure of the plastic packaging bags in Example 1, including the following steps:

[0061] The cardboard box and its internal plastic packaging bag are placed together at the starting end of the conveyor mechanism 100. Then, the staff pinches the opening of the plastic packaging bag and lifts it upwards so that the opening of the plastic packaging bag can smoothly enter between the two moving parts 200. It should be noted that in the initial state, both moving parts 200 are located at the starting end, and the conveyor mechanism 100 is always in operation. After the staff places the cardboard box on the conveyor mechanism 100, they must immediately lift the opening of the packaging bag.

[0062] Under the action of the two limiting plates 101, the length direction of the carton can be kept consistent with the length direction of the conveying mechanism 100. When the front end of the carton moves to be flush with the distance sensor 700, the controller 800 immediately starts the linear slide 300 and the first solenoid valve 402.

[0063] The linear slide 300 is used to drive the moving part 200 to move, and the moving speed of the moving part 200 is consistent with the forward speed of the carton. After the first solenoid valve 402 is opened, the negative pressure suction assembly is used to attract the top of the packaging bag to open its opening.

[0064] Since the roller 507 can slide along the track 107, when the roller 507 enters the second horizontal section 1073, the suction part 503 can extend into the bag opening. At the same time, since the roller 507 is in contact with the conductive strip 601, the second solenoid valve 405 opens, and the suction part 503 begins to suck the air inside the packaging bag. Immediately afterwards, the roller 210 moves to fit against the extrusion track 104, and the two sponge blocks 208 approach each other and clamp the bag opening and the suction part 503 to temporarily seal the bag opening, so that the suction part 503 can suck the air inside the packaging bag clean.

[0065] When the roller 507 enters the third horizontal section 1075, the controller 800 immediately controls the first solenoid valve 402 to close, thereby causing the suction cup 205 to release the packaging bag. At the same time, the controller immediately controls the electric push rod 105 to work, causing the two hot press heads 106 to move closer to each other and press the bag opening, thereby sealing the bag opening. When the roller 507 moves to the end of the third horizontal section 1075, the controller immediately controls the electric push rod 105 to work again, causing the hot press head 106 to retract and reset. In this state, the sponge block 208 has also released the packaging bag. Therefore, with the continuous conveying of the conveyor mechanism 100, the carton and the plastic packaging bag inside can be transported out together.

[0066] After the above steps are completed, the controller 800 controls the linear slide 300 to move the moving part 200 to the starting end. This process is repeated to continuously seal the plastic packaging bag.

[0067] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heat-sealing structure for a plastic packaging bag, characterized in that, include: A conveying mechanism (100) is provided with symmetrical limiting plates (101) on the left and right sides of the top surface of the conveying mechanism (100). The front and rear ends of the limiting plates (101) are arc-shaped, and the distance between the two limiting plates (101) is adapted to the width of the carton being transported. Above the conveying mechanism (100) and between the two limiting plates (101), there are also two limiting frames (102). The two limiting frames (102) are symmetrically distributed on the left and right. The height of the limiting frames (102) is higher than the height of the carton and lower than the top height of the packaging bag. The front and rear ends of the limiting frames (102) are provided with columns (103), and the columns (103) are fixedly connected to the conveying mechanism (100). The movable part (200) corresponds one-to-one with the limiting frame (102). The movable part (200) is slidably connected to the corresponding limiting frame (102). The length of the movable part (200) is adapted to the length of the carton. Negative pressure suction components are provided on the facing surfaces of the two movable parts (200) to attract the top of the packaging bag and open its opening. Sponge squeezing components are also provided on the facing surfaces of the two movable parts (200). The two sponge squeezing components are used to squeeze each other to close the opening of the packaging bag. A suction mechanism (500) is located directly above the two movable parts (200). The suction mechanism (500) is used to extend into the packaging bag and extract the air from the packaging bag. A negative pressure source (400) is connected to the negative pressure suction component and the suction mechanism (500) and is used to provide negative pressure to the negative pressure suction component and the suction mechanism (500); Among them, the two moving parts (200) are provided with an inner groove (213) on their facing surfaces, and electric push rods (105) are provided on the back surfaces of the two moving parts (200). A hot press head (106) is movably provided in each of the two inner grooves (213). The movable ends of the two electric push rods (105) extend into the inner grooves (213) and are fixedly connected to the corresponding hot press head (106). The suction mechanism (500) includes a lifting part (501), the inside of which is provided with a negative pressure cavity (502). The bottom surface of the lifting part (501) is provided with a flat suction part (503), which communicates with the negative pressure cavity (502). The top surface of the lifting part (501) is also provided with an air nozzle (504) that communicates with the negative pressure cavity (502). The air nozzle (504) is connected to the negative pressure source (400) through a second hose (403). A second solenoid valve (405) is also provided on the second hose (403).

2. The heat-sealing structure of a plastic packaging bag according to claim 1, characterized in that: The moving part (200) has a through hole (201) inside, the limiting frame (102) is inserted into the through hole (201), and the two limiting frames (102) are provided with linear slides (300) on opposite sides. The movable end of the linear slide (300) is fixedly connected to the inner wall of the through hole (201).

3. The heat-sealing structure of a plastic packaging bag according to claim 2, characterized in that: The top facing surfaces of the two moving parts (200) are provided with suction chambers (202), and the top facing back surfaces of the two moving parts (200) are provided with suction heads (203) that communicate with the suction chambers (202). The negative pressure suction assembly includes a sealing cover plate (204) and a plurality of suction cups (205) disposed on the sealing cover plate (204). The sealing cover plate (204) covers the inside of the suction chamber (202). The suction cups (205) communicate with the suction chamber (202). The suction head (203) is connected to the negative pressure source (400) through a first hose (401). A first solenoid valve (402) is disposed on the first hose (401).

4. The heat-sealing structure of a plastic packaging bag according to claim 3, characterized in that: The conveying mechanism (100) is also provided with a ranging sensor (700) and a controller (800). When the moving part (200) is located at the starting end, the ranging sensor (700) is flush with the rear end of the moving part (200). The signal output end of the ranging sensor (700) is connected to the controller (800). The signal output end of the controller (800) is connected to the linear slide (300), the first solenoid valve (402), and the electric push rod (105).

5. The heat-sealing structure of a plastic packaging bag according to claim 1, characterized in that: Both of the moving parts (200) have extrusion grooves (206) on their bottom facing surfaces. The sponge extrusion assembly includes an extrusion plate (207), a sponge block (208), and a push rod (209). The extrusion plate (207) is movably disposed in the corresponding extrusion groove (206). The sponge block (208) is disposed on the facing surfaces of the two extrusion plates (207). The push rod (209) is disposed on the facing back surfaces of the two extrusion plates (207).

6. The heat-sealing structure of a plastic packaging bag according to claim 5, characterized in that: The push rod (209) with one end facing away from the extrusion plate (207) moves through the back of the moving part (200) and is provided with a rolling wheel (210). The top facing surfaces of the two limiting plates (101) are provided with extrusion rails (104). A limiting spring (212) is connected between the extrusion plate (207) and the inner wall of the extrusion groove (206). In the natural state, the limiting spring (212) is in a stretched state, and the rolling wheel (210) abuts against the inner surface of the limiting plate (101). When the moving part (200) moves to the area between the two extrusion rails (104), the rolling wheel (210) rolls and fits against the extrusion rail (104), and the two sponge blocks (208) fit against each other.

7. The heat-sealing structure of a plastic packaging bag according to claim 1, characterized in that: The lifting part (501) has guide rods (505) vertically installed at the four corners of its bottom surface. Each of the two moving parts (200) has an extension block (211) on its opposite side. The guide rods (505) movably pass through the corresponding extension blocks (211). Each of the two limiting plates (101) has a travel track (107) on its opposite side. Vertical rods (506) are symmetrically installed on the left and right sides of the bottom surface of the lifting part (501). Rollers (507) are installed at the bottom of the vertical rods (506) and are movably inserted into the travel track (107). The travel track (107) is... The five-segment structure consists of a first horizontal segment (1071), a descending segment (1072), a second horizontal segment (1073), an ascending segment (1074), and a third horizontal segment (1075). When the roller (507) is located inside the first horizontal segment (1071) and the third horizontal segment (1075), the suction part (503) is located above the moving part (200). When the roller (507) is located inside the second horizontal segment (1073), the suction part (503) extends between the two moving parts (200), and the bottom end of the suction part (503) is lower than the moving part (200).

8. The heat-sealing structure of a plastic packaging bag according to claim 7, characterized in that: The conveying mechanism (100) is provided with a power supply (600) on the outside, and a conductive strip (601) is provided in the second horizontal section (1073). The two conductive strips (601) are respectively connected to the positive and negative terminals of the power supply (600). The roller (507) is made of copper pillar. The two leads of the second solenoid valve (405) are respectively connected to the two rollers (507). When the roller (507) enters the interior of the second horizontal section (1073), the second solenoid valve (405) opens.

9. A method for using a heat-sealing structure for a plastic packaging bag, applicable to the heat-sealing structure of the plastic packaging bag as described in claim 4, characterized in that, Includes the following steps: The cardboard box and its internal plastic packaging bag are placed together at the starting end of the conveyor (100). Then, the staff pinches the opening of the plastic packaging bag and lifts it upward so that the opening of the plastic packaging bag can smoothly enter between the two moving parts (200). Under the action of the two limiting plates (101), the length direction of the carton can be kept consistent with the length direction of the conveying mechanism (100). When the front end of the carton moves to be flush with the distance sensor (700), the controller (800) immediately starts the linear slide (300) and the first solenoid valve (402). The linear slide (300) is used to drive the moving part (200) to move, and the moving speed of the moving part (200) is consistent with the forward speed of the carton. After the first solenoid valve (402) is opened, the negative pressure suction assembly is used to attract the top of the packaging bag to open its opening. Then, the sponge squeezing assembly is used to press the opening of the packaging bag, and the suction mechanism (500) is used to suck the air inside the packaging bag. Finally, two hot press heads (106) are used to press the opening of the packaging bag together to seal the opening.

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