Heat sealing device for bag making machine

Abstract

The heat sealing device for the bag making machine is used for conducting heat sealing on a plastic film and comprises a heat sealing cutter movably arranged in the vertical direction, a heat sealing table used for bearing the plastic film to be subjected to heat sealing is horizontally arranged below the heat sealing cutter, and an expanding mechanism is arranged on one side of the heat sealing cutter and movably arranged in the vertical direction; the flattening device is used for flattening the plastic film to be subjected to heat sealing on the heat sealing table in the length direction of the heat sealing cutter before the heat sealing cutter conducts heat sealing. The device can effectively prevent the problem of heat sealing failure caused by wrinkles of the plastic film during heat sealing.

Description

Technical Field

[0001] This application belongs to the technical field of heat sealing of bag-making machines, and particularly relates to a heat sealing device for a bag-making machine. Background Art

[0002] In the production and manufacturing process of plastic packaging bags, a heat sealing device in a bag-making machine is required to heat seal plastic bags.

[0003] When the existing bag-making machine performs heat sealing, generally, a linear mechanism is used to push the heat sealing knife down to heat seal the plastic bag on the workbench. After heat sealing, the heat sealing knife moves up, and the conveying mechanism in the bag-making machine conveys the plastic bag, pulling out the heat-sealed end below the heat sealing knife and pulling the unsealed end to below the heat sealing knife, repeating the above operations. However, there are some problems in the actual application process of the bag-making machine. After the conveying mechanism pulls the unsealed end of the plastic bag to below the heat sealing knife, due to the action of inertia, the plastic film to be heat-sealed of the plastic bag often appears wrinkled. In this way, for the heat-sealed plastic bag, because the wrinkled part is unevenly heated, the plastic film at the wrinkled part is not fully adhered, directly affecting the quality of the plastic bag. Utility Model Content

[0004] In order to solve the above deficiencies of the prior art, this application provides a heat sealing device for a bag-making machine, which can effectively prevent the problem of heat sealing failure caused by wrinkling of the plastic film during heat sealing.

[0005] In order to achieve the above purpose, the present utility model adopts the following technologies:

[0006] A heat sealing device for a bag-making machine, used for heat-sealing a plastic film, includes a heat sealing knife movably arranged in the vertical direction. A heat sealing table for carrying the plastic film to be heat-sealed is horizontally arranged below the heat sealing knife. A stretching mechanism is arranged on one side of the heat sealing knife and is movably arranged in the vertical direction, and is used to flatten the plastic film to be heat-sealed on the heat sealing table along the length direction of the heat sealing knife before heat sealing by the heat sealing knife.

[0007] Further, the stretching mechanism includes two mounting blocks that move towards each other in the length direction of the heat sealing knife. One side of the mounting block is rotatably provided with a connecting rod, and its rotation axis is in a horizontal state and perpendicular to one side of the mounting block. A torsion spring is sleeved on the rotation axis of the connecting rod. When the torsion spring is in a natural state, the distal ends of the two connecting rods are separated from each other and face the heat sealing table. The distal end of the connecting rod is provided with a stretching part for contacting the plastic film to be heat-sealed.

[0008] Further, the stretching part includes a mounting frame installed at the distal end of the connecting rod. An installation rod is arranged in the mounting frame, and the axis of the installation rod is parallel to the rotation axis of the connecting rod. A stretching wheel is rotatably arranged on the installation rod along the axis.

[0009] Further, a linear mechanism is vertically installed above the heat-sealing table. An L-shaped plate is arranged below the linear mechanism. A first guide rail is arranged on the inner side wall of the vertical side of the L-shaped plate. Below the horizontal side of the L-shaped plate, a mounting plate is arranged in parallel. The mounting plate is fitted on the first guide rail; the movable end of the linear mechanism passes through the horizontal side of the L-shaped plate and is connected to the mounting plate; a first return spring is arranged between the horizontal side of the L-shaped plate and the mounting plate; an installation groove is arranged along the length direction of the heat-sealing knife at the lower part of the vertical side of the L-shaped plate, and a mounting block is arranged in the installation groove.

[0010] Further, a second guide rail is arranged along the length direction of the heat-sealing knife in the installation groove. The mounting block is fitted on the second guide rail; rack frames are arranged at the top and bottom of the installation groove. A rack that moves along the length direction of the heat-sealing knife is fitted in the rack frame. The rack is connected to the corresponding mounting block; a gear is meshed between the racks. A driving rod is arranged on one side of the gear. The driving rod passes through the side wall of the installation groove and is connected to a knob; pin holes are evenly arranged along the rotation direction of the knob on the outer side of the side wall of the installation groove, and a pin rod is arranged on the knob.

[0011] Further, second return springs are arranged between the mounting block and the side wall of the installation groove.

[0012] The beneficial effects of the present utility model are as follows:

[0013] 1. Through the setting of the heat-sealing knife and the heat-sealing table, and in cooperation with the stretching mechanism, before heat-sealing, the plastic film is in a flat and wrinkle-free state, so that after heat-sealing, the plastic film is bonded evenly and flatly, ensuring the heat-sealing quality of the plastic bag;

[0014] 2. Through the movement setting of the mounting block along the length direction of the heat-sealing knife and the setting of the stretching part, and under the action of the connecting rod and the torsion spring, the distance between the two mounting blocks can be adjusted, that is, the distance between the two stretching parts can be adjusted, so that the device can adapt to the flattening operation of plastic films of various widths and has extremely high applicability;

[0015] 3. The second return spring arranged between the mounting block and the side wall of the installation groove and the setting of the torsion spring enable the two stretching parts to automatically and quickly return to their positions after heat-sealing is completed, improving the automation degree of the device. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the main structure of the device in the embodiment of the present application.

[0017] Figure 2 It is a schematic diagram of the structure of the stretching mechanism in the device in the embodiment of the present application.

[0018] Figure 3 It is a schematic diagram of the structure of the rear part of the vertical side of the L-shaped plate in the device in the embodiment of the present application.

[0019] Reference numerals: 1 - heat-sealing knife, 2 - bearing platform, 3 - stretching mechanism, 31 - mounting block, 32 - connecting rod, 33 - torsion spring, 34 - stretching part, 341 - mounting frame, 342 - mounting rod, 343 - stretching wheel, 4 - linear mechanism, 5 - L-shaped plate, 51 - mounting groove, 511 - second guide rail, 512 - rack frame, 513 - rack, 514 - gear, 515 - driving rod, 516 - knob, 517 - pin rod, 518 - second return spring, 52 - pin hole, 53 - first guide rail, 6 - mounting plate, 61 - first return spring. Detailed implementation manners

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will describe the implementation manners of the present utility model in detail with reference to the accompanying drawings. However, the embodiments described herein are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0021] The embodiment of the present application provides a heat-sealing device for a bag-making machine, as Figure 1 shown, which includes a heat-sealing knife 1 movably arranged in the vertical direction. A heat-sealing platform 2 for bearing the plastic film to be heat-sealed is horizontally arranged below the heat-sealing knife 1. A stretching mechanism 3 is arranged on one side of the heat-sealing knife 1 and is movably arranged in the vertical direction for flattening the plastic film to be heat-sealed on the heat-sealing platform 2 along the length direction of the heat-sealing knife 1 before the heat-sealing knife 1 performs heat-sealing.

[0022] Specifically, in application, the conveying mechanism in the bag-making machine pulls the plastic film to be heat-sealed and pulls one end of the plastic film to be heat-sealed onto the heat-sealing platform 2 under the heat-sealing knife 1. Generally, a heating device is arranged in the heat-sealing knife 1. After the heat-sealing knife 1 is heated to a suitable temperature, it starts to descend in the vertical direction. At the same time, the stretching mechanism 3 has already descended in the vertical direction and contacts the plastic film, flattening one end of the plastic film to be heat-sealed along the length direction of the heat-sealing knife 1. The heat-sealing knife 1 contacts the plastic film, and through the extrusion between the heat-sealing knife 1 and the heat-sealing platform 2, the plastic at one end of the plastic film is melted and bonded, thus completing the heat-sealing of the plastic film. The conveying mechanism of the bag-making machine pulls out the heat-sealed end from the heat-sealing platform 2 and pulls the next end to be heat-sealed onto the heat-sealing platform 2 under the heat-sealing knife 1, and then repeats the above operation. Before the heat-sealing knife 1 presses the heat-sealing platform 2 each time, the stretching mechanism 3 will first contact the plastic film and flatten one end of the plastic film to be heat-sealed along the length direction of the heat-sealing knife 1, eliminating the wrinkles generated at the heat-sealing end of the plastic film due to inertia during the conveying of the plastic film by the conveying mechanism. After the plastic film is fully flattened, heat-sealing is performed. In this way, the heat-sealing end is evenly heated, adhesively bonded sufficiently, and the heat-sealing effect is good, ensuring the production quality of plastic packaging bags.

[0023] Specifically, as Figure 2As shown in the figure, the stretching mechanism 3 includes two mounting blocks 31 that move towards each other in the length direction of the heat-sealing knife 1. One side of the mounting block 31 is rotatably provided with a connecting rod 32, and its rotation axis is horizontal and perpendicular to one side of the mounting block 31. A torsion spring 33 is sleeved on the rotation axis of the connecting rod 32. When the torsion spring 33 is in its natural state, the distal ends of the two connecting rods 32 are separated from each other and face the heat-sealing table 2. The distal end of the connecting rod 32 is provided with a stretching portion 34 for contacting the plastic film to be heat-sealed. In the actual application process of the bag-making machine, plastic films of various widths are usually heat-sealed. At this time, higher requirements are put forward for the applicability of the stretching mechanism 3. The movement of the two mounting blocks 31 along the length direction of the heat-sealing knife 1 enables the distance between the two stretching portions 34 to be adjusted. In this way, by adjusting the distance between the two mounting blocks 31, the flattening operation of plastic films of various widths can be adapted, which has high applicability. When in use, after the stretching mechanism 3 contacts the plastic film, it continues to descend. The contact between the stretching portion 34 and the plastic film causes the two connecting rods 32 to rotate, and the distal ends of the two connecting rods 32 continue to separate. At the same time, under the action of the torsion spring 33, when the two stretching portions 34 move away from each other along the length direction of the heat-sealing knife 1, they can always press the plastic film tightly. The action of the torsion spring makes the stretching effect of the stretching mechanism 3 good, which can effectively eliminate the wrinkles at the heat-sealing end, and the mechanism is simple, with high practicality. After the heat-sealing is completed, under the action of the torsion spring, the two stretching portions 34 can automatically return to the initial position to prepare for the next heat-sealing, which improves the heat-sealing efficiency of the device, thereby improving the bag-making efficiency of the bag-making machine and further improving the production efficiency of the enterprise.

[0024] Specifically, as Figure 2 shown in the figure, the stretching portion 34 includes a mounting frame 341 installed at the distal end of the connecting rod 32. An installation rod 342 is arranged inside the mounting frame 341. The axis of the installation rod 342 is parallel to the rotation axis of the connecting rod 32. A stretching wheel 343 is rotatably arranged on the installation rod 342 along the axis. When setting the specific mechanism of the stretching portion 34, the method of scraping the plastic film flat with a scraper or rolling it with a roller can be selected. However, in the actual application process, the plastic film is a thin film. When using a scraper to scrape it flat, it is easy to involve the plastic film in the length direction of the heat-sealing knife 1, causing the plastic film to deform, which will affect the heat-sealing quality. In severe cases, the plastic film will be scratched. Therefore, in order to avoid damaging the plastic film when the stretching portion 34 flattens the plastic film, in this embodiment, the stretching portion 34 uses the stretching wheel 343 to roll the plastic film. This can not only eliminate the wrinkles at the heat-sealing end but also ensure that the plastic film is not damaged during rolling, ensuring the heat-sealing quality of the device.

[0025] Specifically, as Figure 2As shown in the figure, a linear mechanism 4 is vertically installed above the heat-sealing table 2. The linear mechanism 4 can be a linear motor or a linear cylinder, etc. In this embodiment, the linear mechanism 4 is a linear cylinder; a L-shaped plate 5 is arranged below the linear mechanism 4. The inner side wall of the vertical side of the L-shaped plate 5 is provided with a first guide rail 53. Below the horizontal side of the L-shaped plate 5, a mounting plate 6 is arranged in parallel. A mating groove is formed on one side of the mounting plate 6 and is engaged with the first guide rail 53. The heat-sealing knife 1 is installed below the mounting plate 6; the movable end of the linear mechanism 4 passes through the horizontal side of the L-shaped plate 5 and is connected to the mounting plate 6; a first return spring 61 is arranged between the horizontal side of the L-shaped plate 5 and the mounting plate 6; an installation groove 51 is arranged along the length direction of the heat-sealing knife 1 at the lower part of the vertical side of the L-shaped plate 5, and the installation block 31 is arranged in the installation groove 51. During application, the linear mechanism 4 drives the heat-sealing knife 1 and the spreading mechanism 3 to descend vertically together. Due to the structure of the L-shaped plate 5, there is a predetermined distance between the heat-sealing knife 1 and the spreading mechanism 3 in the height direction. The heat-sealing knife 1 is located above the spreading mechanism 3. Before the spreading mechanism 3 contacts the plastic film, the first return spring 61 maintains the predetermined distance between the heat-sealing knife 1 and the spreading mechanism 3; the linear mechanism 4 drives the heat-sealing knife 1 and the spreading mechanism 3 to continue to descend. After the spreading mechanism 3 flattens the plastic film and the torsion spring 33 reaches the maximum deformation, the heat-sealing knife 1 continues to descend, and the first return spring 61 starts to stretch. The distance between the heat-sealing knife 1 and the spreading mechanism 3 becomes smaller. When the heat-sealing knife 1 is pressed against the heat-sealing table 2, the spreading wheel 343 always maintains the state of compacting and flattening the plastic film; after the heat-sealing is completed, the linear mechanism 4 drives the heat-sealing knife 1 and the spreading mechanism 3 to rise, and the first return spring 61 enables the heat-sealing knife 1 and the spreading mechanism 3 to continue to maintain the predetermined distance in the height direction. Through the settings of the L-shaped plate 5, the first return spring 61, etc., it is realized that using one power source can complete the flattening operation of the spreading mechanism 3 and the heat-sealing operation of the heat-sealing knife 1, which not only optimizes the structure of the device but also reduces the manufacturing cost of the device.

[0026] Specifically, as Figure 2 and Figure 3As shown in the figure, a second guide rail 511 is provided in the installation groove 51 along the length direction of the heat-sealing knife 1, and the installation block 31 is fitted on the second guide rail 511; rack frames 512 are provided at the top and bottom of the installation groove 51, and racks 513 that move along the length direction of the heat-sealing knife 1 are fitted in the rack frames 512. The racks 513 are connected to the corresponding installation blocks 31 to realize the opposite movement of the installation blocks 31 along the length direction of the heat-sealing knife 1; a gear 514 is meshed between the racks 513, a driving rod 515 is provided on one side of the gear 514, the driving rod 515 passes through the side wall of the installation groove 51 and is connected with a knob 516; pin holes 52 are uniformly arranged along the rotation direction of the knob 516 on the outer side of the side wall of the installation groove 51, and a pin rod 517 is passed through the knob 516. During application, only need to rotate the knob 516 according to the width of the plastic film to be heat-sealed, and then drive the gear 513 to rotate, so that the two racks 513 move towards each other to adjust the distance between the installation blocks 31, that is, adjust the distance between the two spreading parts 34; after the distance between the two spreading parts 34 is adjusted appropriately, only need to insert the pin rod 517 into the corresponding pin hole 52 to lock the distance between the two spreading parts 34. Adjust the distance between the two spreading parts 34 in the way of gear and rack, and lock the distance between the two spreading parts 34 in the way of pin hole and pin rod, which optimizes the mechanism of the device and improves the stability of the spreading mechanism 3 during operation.

[0027] Specifically, as Figure 2 shown in the figure, a second return spring 518 is provided between the installation block 31 and the side wall of the installation groove 51. During application, when the knob 516 is rotated, the installation block 31 starts to adjust the distance against the elasticity of the second return spring 518, and the pin rod 517 is inserted into the corresponding pin hole 52 to lock the distance between the two spreading parts 34; after the heat-sealing is completed, the pin rod 517 is pulled out from the pin hole 52, and under the action of the second return spring 518, the two installation blocks 31 automatically reset, that is, the two spreading parts 34 automatically return to their positions to prepare for adjusting different distances, which further improves the automation degree of the device and the heat-sealing efficiency of the device.

[0028] The above are only the preferred embodiments of the present application and are not used to limit the present application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application.

Claims

1. A heat sealing device for a bag making machine, used for heat sealing a plastic film, characterized in that: The invention comprises a heat sealing knife (1) which is arranged to move in a vertical direction, a heat sealing table (2) which is arranged horizontally below the heat sealing knife (1) and is used to carry a plastic film to be heat-sealed, and a supporting mechanism (3) is arranged on one side of the heat sealing knife (1). The supporting mechanism (3) is arranged to move in a vertical direction and is used to flatten the plastic film to be heat-sealed on the heat sealing table (2) along the length direction of the heat sealing knife (1) before the heat sealing knife (1) performs heat sealing.

2. A heat sealing device for a bag making machine according to claim 1, characterized in that: The support and spreading mechanism (3) comprises two mounting blocks (31) arranged to move towards each other in the length direction of the heat sealing knife (1); a connecting rod (32) is rotatably arranged on one side of the mounting block (31); the rotation axis of the connecting rod (32) is in a horizontal state and is perpendicular to one side of the mounting block (31); a torsion spring (33) is sleeved on the rotation axis of the connecting rod (32); when the torsion spring (33) is in a natural state, the distal ends of the two connecting rods (32) are separated from each other and face the heat sealing table (2); and a support and spreading portion (34) is arranged at the distal end of the connecting rod (32) for contacting a plastic film to be heat-sealed.

3. A heat sealing device for a bag making machine according to claim 2, characterized in that: The support and expansion portion (34) comprises a mounting frame (341) mounted on the far end of the connecting rod (32), a mounting rod (342) being arranged in the mounting frame (341), an axis of the mounting rod (342) being parallel to a rotation axis of the connecting rod (32), and a support and expansion wheel (343) being arranged on the mounting rod (342) for rotation along the axis.

4. A heat sealing device for a bag making machine according to claim 3, characterized in that: A linear mechanism (4) is vertically arranged above the heat-sealing table (2); an L-shaped plate (5) is arranged below the linear mechanism (4); a first guide rail (53) is arranged on the inner side wall of the vertical side of the L-shaped plate (5); a mounting plate (6) is arranged parallel to the horizontal side of the L-shaped plate (5); the mounting plate (6) is matched with the first guide rail (53); and the heat-sealing knife (1) is mounted below the mounting plate (6); the movable end of the linear mechanism (4) passes through the horizontal side of the L-shaped plate (5) and is connected to the mounting plate (6); a first return spring (61) is arranged between the horizontal side of the L-shaped plate (5) and the mounting plate (6); and a mounting groove (51) is arranged at the lower part of the vertical side of the L-shaped plate (5) along the length direction of the heat-sealing knife (1); and the mounting block (31) is arranged in the mounting groove (51).

5. A heat sealing device for a bag making machine according to claim 4, characterized in that: A second guide rail (511) is provided in the installation groove (51) along the length direction of the heat sealing knife (1), and the installation block (31) is matched with the second guide rail (511); a rack frame (512) is provided at the top and bottom of the installation groove (51), and a rack (513) is matched in the rack frame (512) and moves along the length direction of the heat sealing knife (1), and the rack (513) is connected to the corresponding installation block (31); a gear (514) is meshed between the racks (513), and a driving rod (515) is provided on one side of the gear (514), and the driving rod (515) passes through the side wall of the installation groove (51) and is connected to a knob (516); pin holes (52) are evenly distributed on the outer side wall of the installation groove (51) in the rotation direction of the knob (516), and a pin rod (517) is passed through the knob (516).

6. A heat sealing device for a bag making machine according to claim 5, characterized in that: A second return spring (518) is provided between the mounting block (31) and the side wall of the mounting groove (51).

Images