Heat sealing device for food packaging bag

Abstract

The invention discloses a heat sealing device for food packaging bags, which belongs to the field of packaging sealing and comprises a conveyor belt and a rotary heat sealing component fixedly connected to one side of the conveyor belt. The rotary heat sealing device is characterized in that the rotary heat sealing assembly comprises an axial adjusting part fixedly connected to one side of the conveying belt, a shell fixedly connected to the moving end of the axial adjusting part, two rotary conveying parts connected to the lower end of the shell and a rotary heat sealing part; the seat body extends into the packaging bag and preheats the to-be-fused heat-sealing area on the inner wall of the packaging bag, so that an inner-layer heat-sealing material can be directly preheated, heat transfer delay caused by poor heat conductivity of an outer-layer material is reduced, the temperature difference between all layers of materials in a folding area during subsequent rotary heat-sealing is reduced, and the heat-sealing efficiency is improved. The melting consistency of each layer is improved, the sealing strength is improved, the false sealing probability is reduced, the situation that tiny pinholes are formed due to partial incomplete fusion or insufficient fusion is avoided, and the stability and the sealing performance of heat sealing are guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of packaging sealing, and more particularly to a heat sealing device for a food packaging bag. Background Art

[0002] The packaging bag heat sealing device is a key equipment that seals packaging bags through heat and pressure and is widely used in the food industry.

[0003] Food packaging bags can be divided into three-side sealed bags, self-supporting bags, accordion bags and other types according to their structure. The methods of heat sealing food packaging bags include pulse heat sealing, hot plate heat sealing, rotary heat sealing and other methods. Rotary heat sealing is a method of continuous pressure sealing by rotating heated rollers, which runs synchronously with the production line. It has the advantages of high production efficiency and smooth sealing lines. Therefore, rotary heat sealing is the most commonly used heat sealing method in the automated heat sealing production line of food packaging bags. Although the rotary heat sealing method can heat seal three-side sealed bags and self-supporting bags efficiently and stably, when heat sealing accordion bags, the folded structure ("accordion pleats") on both sides of the accordion bags easily forms multi-layer overlapping areas during heat sealing, resulting in uneven material thickness. It is difficult for the heat sealing roller to apply uniform pressure and heat transfer. The material at the fold may be too thick due to accumulation, and the heat cannot penetrate all layers, resulting in local non-fusion or insufficient fusion, forming tiny pinholes. If the oil content of the food in the packaging bag is high, oil leakage and oil soaking will occur at the heat seal of the packaging bag. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention aims to provide a heat sealing device for food packaging bags.

[0005] To solve the above problems, the present invention adopts the following technical solutions.

[0006] A heat sealing device for food packaging bags, comprising a conveyor belt and a rotary heat sealing assembly fixed to one side of the conveyor belt, wherein the rotary heat sealing assembly comprises an axial adjustment portion fixed to one side of the conveyor belt, a housing fixed to a movable end of the axial adjustment portion, two rotary conveying portions connected to the lower end of the housing, and a rotary heat sealing portion;

[0007] It also includes a preheating and melting component connected to the conveyor belt, and the preheating and melting component includes two brackets symmetrically fixed on both sides of the conveyor belt, a top plate fixed to the upper ends of the two brackets, a cylinder and a hot air blower fixed to the upper end of the top plate, a plate located at the lower end of the top plate and fixed to the telescopic end of the cylinder, a seat fixed to the lower end of the plate, an air duct opened inside the seat body, a plurality of air outlets opened on the outer surface of the seat body and connected to the air duct, a tube body one end of which is connected to the output end of the hot air blower and the other end of which is movable through the top plate and connected to the input end of the air duct, and a support assembly respectively connected to one side of the two brackets to open the bag opening.

[0008] Furthermore, a plurality of exhaust ports are provided at the lower end of the plate body, and a flow channel connected to the plurality of exhaust ports is also provided inside the plate body. An exhaust fan is fixedly connected to the upper end of the top plate, and the input end of the exhaust fan is connected to tube body 2. The other end of tube body 2 is movable through the top plate and connected to the output end of the flow channel.

[0009] Furthermore, the rotating conveying part includes two sets of pulleys symmetrically connected to the lower end of the shell, two tensioning pulleys symmetrically connected to the lower end of the shell, two conveying belts respectively sleeved on the two sets of pulleys, and a power part fixed inside the shell and driving the pulleys to rotate.

[0010] Furthermore, a movable groove 1 is opened at the lower end of the shell, and the rotary heat sealing part is located between the two rotating conveying parts, and the rotary heat sealing part includes two slides slidingly connected in the movable groove 1, a screw rod rotatably connected in the movable groove 1 and screwed in the two slides, and two direct heating roller parts respectively fixed at the lower ends of the two slides. A motor 1 is fixedly connected to one side of the shell, and the output shaft of the motor 1 passes through the shell and is fixedly connected to one end of the screw rod.

[0011] Furthermore, two bag opening guide plates are symmetrically fixed to one side of the shell, and two air cooling parts are symmetrically fixed to the other side of the shell.

[0012] Furthermore, a movable groove 2 is provided inside the seat body, and two movable grooves 3 connected to the movable groove 2 are provided at the lower end of the seat body. A stress relief part is connected to the lower end of the seat body, and the stress relief part includes two connecting plates respectively slidably connected to the inner walls of the two movable grooves 3, two electric clamps respectively fixed to the lower ends of the two connecting plates, a pressure roller rotatably connected to one side of the clamping end of the electric clamp, and a shift component connected to the inside of the seat body and driving the two connecting plates to move.

[0013] Furthermore, the shift assembly includes a gear rotatably connected to the inner wall of the movable groove 2, two racks slidingly connected to the inner wall of the movable groove 2 and meshing with the gear, one end of the two racks is respectively fixed to one side of the two connecting plates, the lower end of the seat body is fixed with motor 2, and motor 2 is located between the two electric clamps, the output shaft of motor 2 passes through the movable groove 2 and is fixed with the gear, and the lower end of the seat body is also fixed with a protective cover arranged on the outside of motor 2.

[0014] Furthermore, an inner folding heat penetration part is connected between the two brackets, and the inner folding heat penetration part includes two rotating rods respectively connected to the two brackets at both ends, two dials respectively fixed on the outer surfaces of the two rotating rods, an inclined surface opened at one end of the two dials, an inner cavity opened inside the two dials, a plurality of air outlets 2 opened on one end and the inclined surface of the two dials and connected to the inner cavity, two hot air blowers 2 respectively fixed on one side of the outer surface of the two dials, and the output end of the hot air blower 2 is connected to the input end of the inner cavity, two motors 3 are fixed to one side of one of the brackets, and the output shafts of the two motors 3 pass through the bracket and are respectively fixed to one end of the two rotating rods.

[0015] Furthermore, the support assembly includes a cylinder 2 fixedly connected to one side of the bracket, a side panel located on the other side of the bracket and fixed to the telescopic end of the cylinder 2, two guide rods 1 movably inserted inside the bracket, and a suction cup fixed to one side of the side panel, and one end of the guide rod 1 is fixed to one side of the side panel.

[0016] Furthermore, avoidance grooves are provided inside the two brackets, and anti-displacement thickening parts are connected to the two side panels, and the anti-displacement thickening parts include movable grooves four provided inside the side panels, positioning seats fixed to the inner walls of movable grooves four by bolts, cylinders three fixed to one side of the positioning seats, two guide rods two movably inserted inside the positioning seats, and a hot pressing seat located on one side of the positioning seat and fixed to the telescopic end of cylinder three, and one end of the two guide rods two is fixed to one side of the hot pressing seat.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) This solution is provided with a preheating and melting component. Before the packaging bag is rotary heat-sealed, the seat is used to extend into the interior of the packaging bag and preheat the area of the inner wall of the packaging bag that is to be fused and heat-sealed. The inner layer of heat-sealing material can be preheated directly, reducing the heat transfer delay caused by the poor thermal conductivity of the outer layer material, reducing the temperature difference between the layers of material in the folding area during subsequent rotary heat sealing, improving the melting consistency of each layer, enhancing the sealing strength, reducing the probability of false sealing, avoiding the occurrence of tiny pinholes caused by local non-fusion or insufficient fusion, and ensuring the stability and sealing of the heat seal.

[0019] (2) This solution is equipped with a stress relief unit, which can flatten the inward folds on both sides of the packaging bag through electric clamps and pressure rollers, forcing the folded area to form a flat linear structure, eliminating the curvature or misalignment caused by natural folding, eliminating the air gap and material stress at the fold, ensuring uniform pressure distribution of the heat sealing wheel, avoiding local false sealing caused by wrinkle rebound, reducing the peeling force fluctuation of the sealing line, and at the same time reducing the thickness difference at the fold, improving the heat conduction and cooling rate of the folded edge, and the heat can be conducted to the entire sealing area faster and more evenly during the heat sealing process.

[0020] (3) This solution is provided with an inner fold heat penetration part, which is driven by the motor 3 to rotate the rotating rod and the push rod. While the push rod folds the folds on both sides of the packaging bag inward, the hot air discharged from the air outlet 2 on the inclined surface and the air outlet 2 at one end of the push rod can preheat the outer surface of the inner folds on both sides of the packaging bag, so that the film at the folded folds can be heated from both the outside and the inside at the same time, reducing the temperature gradient in the wall thickness direction. In this way, the inner wall of the fold is preheated, and the outer surface of the fold folded into the bag is preheated. When the outer surface of the packaging bag is heated and heat-sealed by rotary heat sealing, the temperature of the fold from the inside to the outside is closer, the hot melt layer is heated more evenly, and the molten adhesive layer is easier to form a continuous and complete sealing belt when sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the front three-dimensional structure of the present invention;

[0022] Figure 2 It is a schematic diagram of the back three-dimensional structure of the present invention;

[0023] Figure 3 Schematic diagram of the rotary heat sealing assembly structure of the present invention;

[0024] Figure 4 This is a schematic structural diagram of the preheating and melting assembly of the present invention;

[0025] Figure 5 It is a schematic structural diagram of the stress relief portion of the present invention;

[0026] Figure 6 It is a schematic structural diagram of the movable groove 2 and the movable groove 3 of the present invention;

[0027] Figure 7 This is a schematic diagram of the gear, rack and connecting plate structure of the present invention;

[0028] Figure 8 This is a schematic diagram of the structure of the inner folded heat penetration portion of the present invention;

[0029] Figure 9 It is a structural schematic diagram of the anti-movement and thickness-reducing portion of the present invention.

[0030] Description of the numbers in the figure:

[0031] 1. Conveyor belt; 2. Rotary heat sealing assembly; 21. Axial adjustment unit; 22. Housing; 221. Movable slot 1; 23. Bag opening guide plate; 24. Air cooling unit; 25. Rotary conveying unit; 251. Pulley; 252. Conveyor belt; 253. Tensioning pulley; 26. Rotary heat sealing unit; 261. Sliding seat; 262. Screw; 263. Motor 1; 264. Direct heating roller unit; 3. Preheating and melting assembly; 31. Bracket; 311. Avoidance slot; 32. Top plate; 33. Cylinder 1; 34. Plate; 341. Exhaust port; 35. Housing; 351. Air outlet 1; 352. Movable slot 2; 353. Movable slot 3; 36. Hot air blower 1; 361. Tube body one; 37. Exhaust fan; 371. Tube body two; 38. Support assembly; 381. Cylinder two; 382. Side plate; 383. Guide rod one; 384. Suction cup; 4. Stress relief part; 41. Electric clamp; 42. Press roller; 43. Shift assembly; 431. Motor two; 432. Gear; 433. Rack; 434. Connecting plate; 44. Protective cover; 5. Inner fold heat penetration part; 51. Motor three; 52. Rotating rod; 53. Switch bar; 54. Inclined surface; 55. Air outlet two; 56. Hot air blower two; 6. Anti-shift and thickening part; 61. Movable groove four; 62. Positioning seat; 63. Cylinder three; 64. Guide rod two; 65. Hot pressing seat. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] See also Figures 1 to 9 A heat sealing device for food packaging bags includes a conveyor belt 1 and a rotary heat sealing assembly 2 fixed to one side of the conveyor belt 1. The rotary heat sealing assembly 2 includes an axial adjustment portion 21 fixed to one side of the conveyor belt 1, a housing 22 fixed to the movable end of the axial adjustment portion 21, two rotary conveying portions 25 connected to the lower end of the housing 22, and a rotary heat sealing portion 26;

[0034] It also includes a preheating and melting component 3 connected to the conveyor belt 1, and the preheating and melting component 3 includes two brackets 31 symmetrically fixed on both sides of the conveyor belt 1, a top plate 32 fixed to the upper ends of the two brackets 31, a cylinder 33 and a hot air blower 36 fixed to the upper end of the top plate 32, a plate body 34 located at the lower end of the top plate 32 and fixed to the telescopic end of the cylinder 33, a seat body 35 fixed to the lower end of the plate body 34, an air duct opened inside the seat body 35, a plurality of air outlets 351 opened on the outer surface of the seat body 35 and connected to the air duct, a tube body 361 one end of which is connected to the output end of the hot air blower 36 and the other end of which is movable through the top plate 32 and connected to the input end of the air duct, and a support assembly 38 respectively connected to one side of the two brackets 31 to open the bag opening.

[0035] The support assembly 38 includes a cylinder 2 381 fixed to one side of the bracket 31, a side plate 382 located on the other side of the bracket 31 and fixed to the telescopic end of the cylinder 2 381, two guide rods 1 383 movably inserted into the inside of the bracket 31, and a suction cup 384 fixed to one side of the side plate 382, and one end of the guide rod 1 383 is fixed to one side of the side plate 382.

[0036] The lower end of the plate body 34 is provided with a plurality of exhaust ports 341, and the interior of the plate body 34 is also provided with a flow channel connected to the plurality of exhaust ports 341. The upper end of the top plate 32 is fixedly connected to an exhaust fan 37, and the input end of the exhaust fan 37 is connected to the second tube body 371. The other end of the second tube body 371 is movable through the top plate 32 and connected to the output end of the flow channel.

[0037] The rotating conveying part 25 includes two sets of pulleys 251 symmetrically connected to the lower end of the shell 22, two tensioning pulleys 253 symmetrically connected to the lower end of the shell 22, two conveying belts 252 respectively sleeved on the two sets of pulleys 251, and a power part fixed inside the shell 22 and driving the pulleys 251 to rotate.

[0038] A movable groove 221 is provided at the lower end of the shell 22, and the rotary heat sealing part 26 is located between the two rotating conveying parts 25. The rotary heat sealing part 26 includes two slides 261 slidingly connected in the movable groove 221, a screw rod 262 rotatably connected in the movable groove 221 and screwed in the two slides 261, and two direct heating roller parts 264 respectively fixed to the lower ends of the two slides 261. A motor 263 is fixed to one side of the shell 22, and the output shaft of the motor 263 passes through the shell 22 and is fixed to one end of the screw rod 262.

[0039] Two bag opening guide plates 23 are symmetrically fixed to one side of the housing 22 , and two air cooling parts 24 are symmetrically fixed to the other side of the housing 22 .

[0040] By adopting the above technical solution, the accordion packaging bag containing food is placed on the conveyor belt 1, and the conveyor belt 1 transports the packaging bag. After the packaging bag reaches the lower end of the seat body 35, the conveyor belt 1 stops working (detecting the position of the packaging bag can be achieved by a sensor, which is a mature existing technology and will not be described here). The two cylinders 381 work to drive the two side plates 382 to move toward the packaging bag, so that the suction cups 384 on one side of the two side plates 382 contact the two sides of the packaging bag, and the two sides of the packaging bag are sucked by the suction cups 384. The cylinder 381 works and contracts to drive the suction cups 384 to move, so that the packaging bag The bag opening is opened, and then the cylinder 133 is extended to drive the seat body 35 to descend, so that the seat body 35 enters the interior of the packaging bag from the bag opening, and the hot air blower 136 works to send hot air from the tube body 1361 into the air duct in the seat body 35. The hot air is discharged from the air outlet 1351 after passing through the air duct and blown to the area to be heat-sealed on the inner wall of the packaging bag. In this way, the inner layer of heat-sealing material can be directly preheated, reducing the heat transfer delay caused by the poor thermal conductivity of the outer layer material, reducing the temperature difference between the layers of material in the folding area during subsequent rotary heat sealing, improving the melting consistency of each layer, improving the sealing strength, reducing the probability of false sealing, and avoiding local unfusion or The situation of insufficient fusion forming tiny pinholes occurs, which ensures the stability and sealing of the heat seal. After the heating is completed, the control cylinder 1 33 contracts and resets, the seat 35 moves out from the bag opening, the cylinder 2 381 extends and closes the bag opening, and then the conveyor belt 1 drives the packaging bag to continue to move. The packaging bag is guided by the two bag opening guide plates 23 and moves to the rotating conveying part 25. The power part in the shell 22 drives the pulley 251 to rotate, and the pulley 251 rotates to drive the conveying belt 252 to move. The bag opening is clamped between the two adjacent conveying belts 252. The conveying belt 252 can drive the bag opening to move, and the bag opening is The conveyor belt 252 drives the bag to move and reach between two direct-heating roller parts 264 (composed of two rollers rotating in opposite directions, with heating elements placed inside the rollers, and the surfaces of the rollers processed with straight lines, diagonal lines or mesh lines. The bag rotates continuously on the rolling bearings, and the film is heated, pressurized and heat-sealed during the rolling process. It is usually used for longitudinal sealing and has the function of pulling the film forward. It belongs to the existing technology in the field of heat sealing. For example, the ELD-801HW roller sealing machine uses such a roller, which will not be repeated here). The bag mouth of the packaging bag passing between the two direct-heating roller parts 264 is heated and heat-sealed.

[0041] like Figure 5-Figure 7As shown, a movable groove 2 352 is provided inside the seat body 35, and two movable grooves 353 connected to the movable groove 2 352 are provided at the lower end of the seat body 35. The lower end of the seat body 35 is connected to a stress relief part 4, and the stress relief part 4 includes two connecting plates 434 respectively sliding on the inner walls of the two movable grooves 353, two electric clamps 41 respectively fixed to the lower ends of the two connecting plates 434, a pressure roller 42 rotatably connected to one side of the clamping end of the electric clamp 41, and a shifting component 43 connected to the inside of the seat body 35 and driving the two connecting plates 434 to move.

[0042] The shift assembly 43 includes a gear 432 rotatably connected to the inner wall of the movable groove 2 352, two racks 433 slidingly connected to the inner wall of the movable groove 2 352 and meshing with the gear 432, one end of the two racks 433 is respectively fixed to one side of the two connecting plates 434, the lower end of the base body 35 is fixed with the motor 2 431, and the motor 2 431 is located between the two electric clamps 41, the output shaft of the motor 2 431 passes through the movable groove 2 352 and is fixed with the gear 432, and the lower end of the base body 35 is also fixed with a protective cover 44 arranged on the outside of the motor 2 431.

[0043] By adopting the above technical solution, when the seat 35 completes preheating the inner wall of the bag opening, the motor 2 431 works to drive the gear 432 to rotate, the gear 432 rotates to drive the two racks 433 to move, and the two racks 433 drive the two electric clamps 41 to move in opposite directions, so that the clamping ends of the two electric clamps 41 move toward the inner wall of the packaging bag. At this time, the two cylinders 2 381 extend to drive the two suction cups 384 to move toward each other and close the bag opening. The inward folds on both sides of the bag opening are folded into the packaging bag, and the inward folds can enter between the two clamping ends of the electric clamps 41. At this time, the electric clamps 41 work to close the two clamping ends to clamp the folds. Cylinder 1 33 contracts and resets, and the seat 35 moves upward in the packaging bag. During this process, the electric clamp 41 also moves upward with the seat 35. The pressure roller 42 on the clamping end of the electric clamp 41 can move and flatten the inward folded part of the packaging bag, forcing the folded area to form a flat linear structure, eliminating the curvature or dislocation caused by natural folding, eliminating the air gap and material stress at the fold, ensuring that the pressure of the heat sealing wheel is evenly distributed, avoiding local false sealing due to wrinkle rebound, reducing the fluctuation of the peeling force of the sealing line, and at the same time reducing the thickness difference at the fold, improving the heat conduction and cooling rate of the folded edge, and heat can be conducted to the entire sealing area faster and more evenly during the heat sealing process.

[0044] like Figure 4 and Figure 8As shown, an inner fold heat penetration part 5 is also connected between the two brackets 31, and the inner fold heat penetration part 5 includes two rotating rods 52 with two ends respectively connected to the two brackets 31 for rotation, two dials 53 respectively fixed on the outer surfaces of the two rotating rods 52, an inclined surface 54 opened at one end of the two dials 53, an inner cavity opened inside the two dials 53, a plurality of air outlets 2 55 opened on one end of the two dials 53 and on the inclined surface 54 and connected to the inner cavity, two hot air blowers 2 56 respectively fixed on one side of the outer surface of the two dials 53, and the output end of the hot air blower 2 56 is connected to the input end of the inner cavity, one side of one of the brackets 31 is fixed with two motors 3 51, and the output shafts of the two motors 3 51 pass through the bracket 31 and are respectively fixed to one end of the two rotating rods 52.

[0045] By adopting the above technical solution, when the two cylinders 2 381 extend and drive the two suction cups 384 to move toward each other and close the bag opening, the two motors 3 51 work to drive the two rotating rods 52 to rotate, so that the two picks 53 can contact the folds on both sides of the packaging bag and assist in folding the folds on both sides of the packaging bag inward. During the assisted folding process, the hot air blower 2 56 works to deliver hot air into the inner cavity inside the pick 53, and the hot air is discharged through one end of the pick 53 and the multiple air outlets 2 55 on the inclined surface 54, preheating the outer surface of the inward fold of the packaging bag, so that the film at the folded folds can be heated from both the outside and the inside at the same time, reducing the temperature gradient in the wall thickness direction, so that the inner wall of the fold is preheated and the outer surface of the fold folded into the bag is preheated. When the outer surface of the packaging bag is heated and heat-sealed by rotary heat sealing, the temperature from the inside to the outside of the fold is closer, the hot melt layer is heated more evenly, and the molten adhesive layer is easier to form a continuous and complete sealing belt during sealing.

[0046] like Figure 8 and Figure 9 As shown, the two brackets 31 are each provided with a avoidance groove 311, and the two side panels 382 are each connected with an anti-displacement thickening part 6, and the anti-displacement thickening part 6 includes a movable groove four 61 provided inside the side panel 382, a positioning seat 62 fixed to the inner wall of the movable groove four 61 by bolts, a cylinder three 63 fixed to one side of the positioning seat 62, two guide rods two 64 movably inserted into the positioning seat 62, and a hot pressing seat 65 located on one side of the positioning seat 62 and fixed to the telescopic end of the cylinder three 63, and one end of the two guide rods two 64 are fixed to one side of the hot pressing seat 65.

[0047] By adopting the above technical solution, when the seat body 35 preheats the heat-sealed area of the inner wall of the bag opening, the pressure roller 42 flattens the inner folding part, and the strip 53 preheats the outer surface of the inner folding part, the two cylinders 381 extend to drive the two suction cups 384 to move toward each other and close the bag opening. The cylinder 3 63 works to drive the heat pressing seat 65 to move toward the packaging bag, and pre-seal the folding part of the packaging bag by symmetrical heat pressing. The advantage of this is that the folding part is first pressurized and heat-sealed to produce preliminary melt bonding between the folded layers. , preventing the folded edge from shifting or slipping during subsequent transportation, tensioning or heat sealing, greatly reducing the risk of pinholes or leaking seals caused by skewed or warped folded edges; the initial pressure at the folded edge will slightly thin the folded layer, reducing the total thickness difference between the folded edge and the flat area, thereby obtaining more uniform heat conduction and melting depth during the main heat seal (direct heating roller part 264 heat seal), and during the initial pressurized heat seal, the residual air at the folded edge will be squeezed out or softened and discharged, combined with the lower material viscosity after preheating, which can further eliminate bubbles and significantly improve the consistency, strength and airtightness of the main seal.

[0048] Usage: Place the accordion packaging bag containing food on the conveyor belt 1, which transports the packaging bag. After the packaging bag reaches the lower end of the seat body 35, the conveyor belt 1 stops working, the opening assembly 38 sucks the two sides of the packaging bag to open the bag mouth, the cylinder 1 33 works to extend and drive the seat body 35 to descend, so that the seat body 35 enters the interior of the packaging bag from the bag mouth, the hot air blower 1 36 works to send hot air from the pipe body 1 361 into the air duct in the seat body 35, and the hot air is discharged from the air outlet 1 351 after passing through the air duct and blows toward the area to be heat-sealed on the inner wall of the packaging bag; after heating is completed, The second motor 431 drives the gear 432 to rotate, and the rotation of the gear 432 drives the two racks 433 to move, and the clamping ends of the two electric clamps 41 move toward the inner wall of the packaging bag. At the same time, the two cylinders 381 extend to drive the two suction cups 384 to move toward each other and close the bag opening. The two motors 3 51 work to drive the two rotating rods 52 to rotate, so that the two shifting bars 53 can contact the folded parts on both sides of the packaging bag and assist in folding the folded parts on both sides of the packaging bag inward. The inward folded parts on both sides of the bag opening fold into the packaging bag, and the inward folded parts can enter the electric clamps 41. The two clamping ends of the electric clamping jaws 41 are between each other at this time, so that the two clamping ends are closed to clamp the folded part. The air cylinder 1 33 contracts and resets, and the seat body 35 moves upward in the packaging bag. In this process, the electric clamping jaws 41 also move upward with the seat body 35, and the pressure rollers 42 on the clamping ends of the electric clamping jaws 41 can move and flatten the inward folded part of the packaging bag. In this process, the hot air blower 2 56 continues to work to deliver hot air to the inner cavity inside the shifting bar 53, and the hot air is discharged through the multiple air outlets 2 55 on one end of the shifting bar 53 and the inclined surface 54, thereby flattening the inward folded part of the packaging bag. The outer surface of the packaging bag is preheated, and finally the seat body 35 and the electric clamp 41 are moved out of the packaging bag. The operation of the cylinder three 63 can drive the hot pressing seat 65 to move toward the packaging bag, and the folded part inside the packaging bag is first hot-pressed and pre-sealed by symmetrical hot pressing. The conveyor belt 1 drives the packaging bag to continue to move, and the packaging bag is guided by the two bag opening guide plates 23 and then moves to the rotating conveying part 25. The rotating conveying part 25 conveys the bag opening and makes the bag opening reach between the two direct heating roller parts 264. The bag opening of the packaging bag passing between the two direct heating roller parts 264 is heated and heat-sealed.

[0049] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any person skilled in the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of the present invention shall be covered by the scope of protection of the present invention.

Claims

1. A heat sealing device for food packaging bags, comprising a conveyor belt (1) and a rotary heat sealing assembly (2) fixed to one side of the conveyor belt (1), characterized in that: The rotary heat sealing assembly (2) comprises an axial adjustment portion (21) fixedly connected to one side of the conveyor belt (1), a housing (22) fixedly connected to the movable end of the axial adjustment portion (21), two rotary conveying portions (25) connected to the lower end of the housing (22), and a rotary heat sealing portion (26); The bag is provided with a preheating and melting component (3) connected to the conveyor belt (1), and the preheating and melting component (3) includes two brackets (31) symmetrically fixed on both sides of the conveyor belt (1), a top plate (32) fixed on the upper ends of the two brackets (31), a cylinder (33) and a hot air blower (36) fixed on the upper end of the top plate (32), a plate (34) located at the lower end of the top plate (32) and fixed to the telescopic end of the cylinder (33), a seat (35) fixed to the lower end of the plate (34), an air duct opened inside the seat (35), a plurality of air outlets (351) opened on the outer surface of the seat (35) and connected to the air duct, a pipe (361) one end of which is connected to the output end of the hot air blower (36) and the other end of which is movable through the top plate (32) and connected to the input end of the air duct, and a support assembly (38) respectively connected to one side of the two brackets (31) to open the bag opening.

2. The heat sealing device for food packaging bags according to claim 1, characterized in that: The lower end of the plate body (34) is provided with a plurality of air exhaust ports (341), and a flow channel connected to the plurality of air exhaust ports (341) is also provided inside the plate body (34). The upper end of the top plate (32) is fixedly connected with an exhaust fan (37), and the input end of the exhaust fan (37) is connected to the second pipe body (371), and the other end of the second pipe body (371) is movable through the top plate (32) and connected to the output end of the flow channel.

3. The heat sealing device for a food packaging bag according to claim 2, characterized in that: The rotating conveying portion (25) comprises two groups of pulleys (251) symmetrically connected to the lower end of the housing (22), two tensioning pulleys (253) symmetrically connected to the lower end of the housing (22), two conveying belts (252) respectively sleeved on the two groups of pulleys (251), and a power portion fixed inside the housing (22) and driving the pulleys (251) to rotate.

4. The heat sealing device for a food packaging bag according to claim 3, characterized in that: A movable groove (221) is provided at the lower end of the shell (22), and the rotary heat sealing part (26) is located between the two rotating conveying parts (25). The rotary heat sealing part (26) includes two slides (261) slidably connected in the movable groove (221), a screw (262) rotatably connected in the movable groove (221) and screwed in the two slides (261), and two direct heating roller parts (264) respectively fixed at the lower ends of the two slides (261). A motor (263) is fixed to one side of the shell (22), and the output shaft of the motor (263) passes through the shell (22) and is fixed to one end of the screw (262).

5. The heat sealing device for food packaging bags according to claim 4, characterized in that: Two bag opening guide plates (23) are symmetrically fixed to one side of the shell (22), and two air cooling parts (24) are symmetrically fixed to the other side of the shell (22).

6. The heat sealing device for food packaging bags according to claim 5, characterized in that: A movable groove 2 (352) is provided inside the seat body (35), and two movable grooves 3 (353) connected to the movable groove 2 (352) are provided at the lower end of the seat body (35). A stress relief portion (4) is connected to the lower end of the seat body (35), and the stress relief portion (4) includes two connecting plates (434) respectively slidably connected to the inner walls of the two movable grooves 3 (353), two electric clamps (41) respectively fixed to the lower ends of the two connecting plates (434), a pressure roller (42) rotatably connected to one side of the clamping end of the electric clamp (41), and a shifting component (43) connected to the inside of the seat body (35) and driving the two connecting plates (434) to move.

7. The heat sealing device for food packaging bags according to claim 6, characterized in that: The shift assembly (43) includes a gear (432) rotatably connected to the inner wall of the movable groove (352), two racks (433) slidably connected to the inner wall of the movable groove (352) and meshing with the gear (432), one end of the two racks (433) is respectively fixed to one side of two connecting plates (434), the lower end of the seat (35) is fixed with a motor (431), and the motor (431) is located between the two electric clamps (41), the output shaft of the motor (431) passes through the movable groove (352) and is fixed to the gear (432), and the lower end of the seat (35) is also fixed with a protective cover (44) arranged on the outside of the motor (431).

8. The heat sealing device for food packaging bags according to claim 7, characterized in that: An inner folding heat penetration part (5) is also connected between the two brackets (31), and the inner folding heat penetration part (5) includes two rotating rods (52) whose two ends are respectively connected to the two brackets (31) for rotation, two shifting bars (53) respectively fixed on the outer surfaces of the two rotating rods (52), an inclined surface (54) opened at one end of the two shifting bars (53), an inner cavity opened inside the two shifting bars (53), a plurality of air outlets (55) opened at one end of the two shifting bars (53) and on the inclined surface (54) and connected to the inner cavity, and two hot air blowers (56) respectively fixed on one side of the outer surface of the two shifting bars (53), and the output end of the hot air blower (56) is connected to the input end of the inner cavity, one side of one of the brackets (31) is fixed with two motors (51), and the output shafts of the two motors (51) pass through the bracket (31) and are respectively fixed to one end of the two rotating rods (52).

9. The heat sealing device for food packaging bags according to claim 8, characterized in that: The support assembly (38) includes a second cylinder (381) fixedly connected to one side of the bracket (31), a side plate (382) located on the other side of the bracket (31) and fixedly connected to the telescopic end of the second cylinder (381), two guide rods (383) movably inserted into the interior of the bracket (31), and a suction cup (384) fixedly connected to one side of the side plate (382), wherein one end of the guide rod (383) is fixedly connected to one side of the side plate (382).

10. The heat sealing device for food packaging bags according to claim 9, characterized in that: The two brackets (31) are provided with avoidance grooves (311) inside, and the two side plates (382) are connected with anti-displacement and thickening parts (6), and the anti-displacement and thickening parts (6) include a movable groove four (61) provided inside the side plate (382), a positioning seat (62) fixed on the inner wall of the movable groove four (61) by bolts, a cylinder three (63) fixed on one side of the positioning seat (62), two guide rods two (64) movably inserted inside the positioning seat (62), and a hot pressing seat (65) located on one side of the positioning seat (62) and fixed to the telescopic end of the cylinder three (63), and one end of the two guide rods two (64) is fixed to one side of the hot pressing seat (65).

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