A hot press forming machine for seamless plastic bags

Abstract

The utility model relates to hot pressing processing technical field of seamless plastic bag, especially hot forming machine of seamless plastic bag. Hot forming machine of seamless plastic bag includes mounting bracket, the knife rest of adjustable rotation around its own axis is assembled on mounting bracket, three groups of annular distribution's mounting plate are fixedly installed on the knife rest, and every group two mounting plates between all assemble a hot pressing plate and two electric heating plates, and the both ends of electric heating plate all assemble the electrically conductive column, and the both ends of knife rest all fixedly install the pivot, the utility model discloses three groups of switchable use's hot pressing plate are installed on the knife rest, when the hot pressing plate of work position appears wear and tear and needs to maintain, need not stop working and can drive the knife rest rotation through external drive equipment, will non - work position's spare hot pressing plate fast switching to work position, continues to the hot pressing treatment to plastic bag base material, avoids the production interruption caused by the replacement hot pressing plate of stop working, guarantees hot pressing operation continuous steady carries out, improves work efficiency.

Description

Technical Field

[0001] This utility model relates to the field of hot pressing technology for seamless plastic bags, and in particular to a hot pressing machine for seamless plastic bags. Background Technology

[0002] Seamless plastic bags are widely used in food packaging, medical protection, and daily necessities storage due to their excellent sealing performance, high structural strength, and smooth appearance. Their core manufacturing process relies on thermoforming technology, which uses electric heating elements to generate heat and apply pressure to melt and bond the heat-sealing areas of the plastic film, forming a seamless sealing structure. This is a key process that determines the sealing reliability and product quality of plastic bags.

[0003] Most mainstream seamless plastic bag thermoforming equipment currently uses a single thermoforming unit structure, meaning the equipment is equipped with only one thermoforming mold and matching electric heating components. The thermoforming unit is driven by a drive mechanism to lift and lower to achieve continuous thermoforming. However, as the core component that directly contacts the plastic film, the thermoforming mold is prone to wear, deformation, or plastic residue adhesion under long-term high-temperature and high-pressure operation. When the performance of the thermoforming mold deteriorates and needs to be replaced or maintained, the machine must be stopped and disassembled. Production can only resume after the replacement is completed and the parameters are readjusted. For large-scale production lines, a single shutdown for maintenance usually takes tens of minutes or even hours, causing production interruption and seriously affecting overall production efficiency.

[0004] Therefore, it is necessary to provide a new thermoforming machine for seamless plastic bags to solve the above-mentioned technical problems. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a new thermoforming machine for seamless plastic bags.

[0006] The thermoforming machine for seamless plastic bags provided by this utility model includes: a mounting frame installed on the frame of the thermoforming machine; a blade holder that can rotate and adjust around its own axis is mounted on the mounting frame; three sets of ring-shaped mounting plates are fixedly mounted on the blade holder; a thermoforming plate and two heating plates are mounted between two mounting plates in each set; conductive posts are mounted at both ends of the heating plates; rotating shafts are fixedly mounted at both ends of the blade holder; sleeves are rotatably connected to the two rotating shafts; an arc-shaped groove is opened on the side wall of the sleeve for the conductive posts to pass through when rotating with the blade holder; an installation groove is opened on the inner wall of the arc-shaped groove; a slider is slidably connected in the installation groove; a spring is installed in the installation groove; and the two ends of the spring abut against the bottom of the installation groove and the end of the slider, respectively; a conductive block is installed in the arc-shaped groove and fixedly connected to the slider; the conductive block abuts tightly against the conductive posts on the two heating plates directly below.

[0007] Support cylinders are also sleeved on the two rotating shafts. Support plates that can be raised and lowered in the vertical direction are fixedly installed on the outer circumference of the support cylinders. Fixing plates that are fixedly connected to the sleeves are mounted on the support plates.

[0008] Preferably, two lifting cylinders for controlling the raising and lowering of the tool holder are fixedly installed on the mounting frame, and a lifting piston rod is fixedly installed at the output end of each of the two lifting cylinders. The bottom of the two lifting piston rods is detachably connected to the upper end of the two support plates respectively.

[0009] Preferably, a horizontal plate is fixedly installed at the bottom of both lifting piston rods, and a strip-shaped opening is provided on the horizontal plate. A fastening bolt is threadedly connected to the support plate, and the end of the fastening bolt passes through the strip-shaped opening and abuts against the upper side wall of the horizontal plate. The fastening bolt and the strip-shaped opening are slidably engaged to realize the relative position adjustment of the support plate and the horizontal plate.

[0010] Preferably, the ends of the two rotating shafts that are far apart from each other are provided with a chamfered structure.

[0011] Preferably, the conductive block has an arc-shaped structure and is located inside the arc-shaped groove. Both ends of the conductive block are provided with arc-shaped steps, and the curvature of the arc-shaped steps is adapted to the curvature of the outer circumference of the conductive column.

[0012] Preferably, both ends of the two rotating shafts are provided with Y-shaped docking grooves, and a connecting frame is fixedly installed on one side of one of the support plates. A drive motor is fixedly installed on the connecting frame, and a Y-shaped plug inserted into the Y-shaped docking groove is fixedly installed at the output end of the drive motor.

[0013] Preferably, a connecting frame is also fixedly installed on one side of the other support plate. An installation cylinder is fixedly installed on the connecting frame, and a limit cylinder is fixedly installed on the installation cylinder. A limit piston rod is fixedly installed at the output end of the limit cylinder, and a Y-shaped limit block is fixedly installed at the end of the limit piston rod. A Y-shaped groove is opened on the connecting frame, and the Y-shaped limit block passes through the Y-shaped groove and its end is inserted into the Y-shaped docking groove.

[0014] Preferably, the opening of the Y-shaped docking groove is provided with a chamfered structure, and the end of the Y-shaped insert block away from the drive motor and the end of the Y-shaped limiting block away from the limiting piston rod are both provided with a chamfered structure.

[0015] Compared with related technologies, the thermoforming machine for seamless plastic bags provided by this utility model has the following advantages:

[0016] This invention features three sets of switchable hot pressing units mounted on the tool holder. When the hot pressing plate in the working position becomes worn and requires maintenance, the tool holder can be rotated via an external drive device without stopping the machine. This quickly switches the spare hot pressing plate from the non-working position to the working position, continuing the hot pressing process on the plastic bag substrate. This avoids production interruptions caused by stopping the machine to replace the hot pressing plate, ensuring continuous and stable hot pressing operations and improving work efficiency. By switching the hot pressing plates, the three sets of hot pressing plates can alternately enter the working position, avoiding long-term high-load operation of a single hot pressing plate, slowing down the wear rate, and extending the overall service life. Attached Figure Description

[0017] Figure 1 A schematic diagram of a preferred embodiment of the thermoforming machine for seamless plastic bags provided by this utility model;

[0018] Figure 2 for Figure 1 The diagram shows the structure of the mounting bracket.

[0019] Figure 3 for Figure 1 The diagram shows the structure of the tool holder.

[0020] Figure 4 for Figure 1 The diagram shows the structure of the sleeve.

[0021] Figure 5 for Figure 4 The diagram shows the structure of the conductive block.

[0022] Figure 6 for Figure 1 The diagram shows the structure of one of the connecting frames;

[0023] Figure 7 for Figure 1 The diagram shows the structure of another connecting frame.

[0024] The following are the labeling elements in the diagram: 1. Mounting bracket; 11. Lifting cylinder; 12. Lifting piston rod; 13. Horizontal plate; 131. Strip opening; 14. Support plate; 15. Support cylinder; 16. Fastening bolt; 2. Tool holder; 21. Mounting plate; 22. Hot press plate; 23. Electric heating plate; 231. Conductive column; 24. Rotating shaft; 241. Y-shaped docking groove; 3. Sleeve; 31. Fixing plate; 32. Arc-shaped groove; 33. Mounting groove; 34. Conductive block; 35. Slider; 36. Spring; 4. Connecting bracket; 41. Drive motor; 42. Y-shaped insert; 43. Y-shaped slide; 44. Mounting cylinder; 45. Limiting cylinder; 46. Limiting piston rod; 47. Y-shaped limiting block. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0026] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0027] Please see Figures 1 to 7 This utility model provides a thermoforming machine for seamless plastic bags. The thermoforming machine includes: a mounting frame 1 installed on the frame of the thermoforming machine; a blade holder 2 that can rotate and adjust around its own axis mounted on the mounting frame 1; three sets of annularly distributed mounting plates 21 fixedly mounted on the blade holder 2; and a thermoforming plate 22 and two heating plates 23 mounted between each set of two mounting plates 21. Conductive posts 231 are mounted at both ends of each heating plate 23. Rotating shafts 24 are fixedly mounted at both ends of the blade holder 2. Sleeves 3 are rotatably connected to each of the two rotating shafts 24. The side walls of the sleeves 3 are provided with openings for the conductive posts 231 to rotate with the blade holder 2. An arc-shaped groove 32 is passed through, and an installation groove 33 is provided on the inner wall of the arc-shaped groove 32. A slider 35 is slidably connected in the installation groove 33. A spring 36 is installed in the installation groove 33, and the two ends of the spring 36 abut against the bottom of the installation groove 33 and the end of the slider 35, respectively. A conductive block 34 is installed in the arc-shaped groove 32 and is fixedly connected to the slider 35. The conductive block 34 abuts tightly against the conductive post 231 on the two heating plates 23 located directly below. A support cylinder 15 is also sleeved on the two rotating shafts 24. A support plate 14 that can be raised and lowered in the vertical direction is fixedly installed on the outer circumference of the support cylinder 15. A fixing plate 31 that is fixedly connected to the sleeve 3 is assembled on the support plate 14.

[0028] It should be noted that: the mounting frame 1 in this utility model is fixed on the frame of the hot press forming machine. The tool holder 2 is assembled on the mounting frame 1 through the support cylinder 15 and the support plate 14 sleeved on the rotating shaft 24 at both ends. The tool holder 2 can rotate freely around its own axis and rise and fall. The sleeve 3 is fixedly connected to the support plate 14 through the fixing plate 31 and cannot rotate. There are three sets of ring-shaped mounting plates 21 on the tool holder 2. In each set, two mounting plates 21 clamp and fix a hot press plate 22 (the hot press mold in the original hot press forming machine) and two electric heating plates 23 to form three independent hot press units. The conductive posts 231 at both ends of the electric heating plates 23 extend to both sides of the tool holder 2 to prepare for subsequent conductivity. Since the three sets of hot press units are ring-shaped on the tool holder 2, the rotation of the tool holder 2 will drive the three sets of hot press units. Synchronous circular motion enables the hot pressing unit to switch cyclically between the "non-working position" and the "directly below working position," laying the foundation for continuous operation. When a group of hot pressing units rotates with the tool holder 2 to the directly below working position, the conductive posts 231 of the heating plates 23 on both sides of the unit precisely enter the arc-shaped grooves 32 on the side wall of the sleeve 3, and tightly abut against the conductive blocks 34 in the arc-shaped grooves 32. During this process, the spring 36 continuously provides elastic force to the slider 35, which presses the conductive blocks 34 tightly against the conductive posts 231 to avoid poor conductivity due to contact gaps. After the conductive blocks 34 are connected to external power, the current is transmitted through the conductive blocks 34 to the conductive posts 231, and then from the conductive posts 231 to the heating plates 23, causing the heating plates 23 to heat up rapidly. The heating plates 23 then heat... The heat is transferred to the hot press plate 22, which is in close contact with it, causing the temperature of the hot press plate 22 to rise to the process temperature required for the seamless plastic bag hot pressing, thus completing the temperature preparation before hot pressing. When the hot press plate 22 reaches the set temperature, the plastic bag substrate conveyed below is transported to directly below the hot press plate 22. At this time, the support plate 14 can be raised and lowered in the vertical direction, driving the support cylinder 15, the knife holder 2, and the hot pressing unit to move down as a whole, so that the hot press plate 22 is in close contact with the plastic bag substrate and pressure is applied. Through the combined action of heat and pressure, the seamless heat sealing of the plastic bag substrate is achieved. After the hot pressing unit completes one hot pressing, the support plate 14 drives the hot pressing unit to move up and reset. After long-term use, the hot press plate 22 at the working position will wear down due to various environmental influences, which may cause the hot pressing surface to become worn. Decreased flatness leads to problems such as irregular edges and insufficient sealing of the plastic bag heat-sealed surface. To address this, after a certain amount of plastic bag substrate is heat-pressed, an external drive device rotates the blade holder 2, causing the unused heat-pressing plate 22, which was previously in a non-working position, to rotate to the working position below, continuing the heat-pressing process on the plastic bag substrate. This invention installs three sets of switchable heat-pressing units on the blade holder 2. When the heat-pressing plate 22 in the working position becomes worn and requires maintenance, the external drive device can rotate the blade holder 2 without stopping the machine, quickly switching the spare heat-pressing plate 22 from the non-working position to the working position to continue the heat-pressing process on the plastic bag substrate. This avoids production interruptions caused by stopping to replace the heat-pressing plate 22, ensuring continuous and stable heat-pressing operations and improving work efficiency.By switching the hot press plates 22, the three sets of hot press plates 22 can alternately enter the working position, avoiding long-term high-load operation of a single hot press plate, slowing down the wear rate, and extending the overall service life.

[0029] The two rotating shafts 24 are provided with chamfered structures at their ends that are far apart from each other. The chamfered structures transform the right angles at the ends of the rotating shafts 24 into inclined transition surfaces, which facilitates the quick alignment of the inner holes of the support cylinder 15 and the sleeve 3 with the rotating shafts 24, allowing the components to slide smoothly along the chamfered surfaces and be fitted into the designated positions, thus reducing the difficulty of assembly.

[0030] The conductive block 34 has an arc-shaped structure and is located inside the arc-shaped groove 32. Both ends of the conductive block 34 are provided with arc-shaped steps, and the curvature of the arc-shaped steps is adapted to the curvature of the outer circumference of the conductive column 231. This facilitates the sliding of the conductive column 231 on the side heating plate 23 onto the conductive block 34 during the switching of the hot press plate 22, thus avoiding switching jams.

[0031] It is worth noting that both shafts 24 have Y-shaped docking slots 241 at their ends. A connecting frame 4 is fixedly installed on one side of a support plate 14. A drive motor 41 is fixedly installed on the connecting frame 4, and a Y-shaped plug 42 inserted into the Y-shaped docking slot 241 is fixedly installed at the output end of the drive motor 41. The drive motor 41 is the power source for the rotation of the tool holder 2. After the Y-shaped plug 42 is inserted into the Y-shaped docking slot 241, the three branches of the plug are tightly fitted with the three inner walls of the docking slot. When the drive motor 41 starts, the torque can be evenly transmitted to the shaft 24 through the multiple contact surfaces of the Y-shaped plug 42. The shaft 24 then drives the tool holder 2 to rotate around its own axis to switch the hot press plate 22.

[0032] It is also worth noting that a connecting frame 4 is fixedly installed on one side of the other support plate 14. An installation cylinder 44 is fixedly installed on the connecting frame 4, and a limit cylinder 45 is fixedly installed on the installation cylinder 44. A limit piston rod 46 is fixedly installed at the output end of the limit cylinder 45, and a Y-shaped limit block 47 is fixedly installed at the end of the limit piston rod 46. A Y-shaped groove 43 is opened on the connecting frame 4, and the Y-shaped limit block 47 passes through the Y-shaped groove 43 and its end is inserted into the Y-shaped docking groove 241. After the Y-shaped limit block 47 is inserted into the Y-shaped docking groove 241, the three branches of its Y-shaped structure fit tightly against the inner wall of the docking groove, which can limit the radial displacement of the rotating shaft 24 from multiple directions, thus preventing the rotating shaft 24 from moving closer to or further away from the groove. The directional offset of the hot-pressed substrate also prevents the rotating shaft 24 from wobbling left and right in the horizontal direction, ensuring that the knife holder 2 always stays in the set rotation axis position, thereby ensuring the alignment accuracy between the hot-press plate 22 and the plastic bag substrate, allowing the hot-pressing force to be applied evenly to the heat-sealing area of ​​the substrate, and improving the heat-sealing quality stability of the seamless plastic bag. Before switching the hot-press plate 22, the limiting cylinder 45 on the mounting cylinder 44 controls the limiting piston rod 46 to retract, thereby separating the Y-shaped limiting block 47 from the Y-shaped docking groove 241, so that the hot-press plate 22 can be switched. The Y-shaped limiting block 47 slides in the Y-shaped sliding groove 43, and the Y-shaped sliding groove 43 further restricts the Y-shaped limiting block 47, ensuring the stability of the lateral movement of the Y-shaped limiting block 47.

[0033] The opening of the Y-shaped docking groove 241 is provided with a chamfered structure, and the end of the Y-shaped insert 42 away from the drive motor 41 and the end of the Y-shaped limiting block 47 away from the limiting piston rod 46 are also provided with chamfered structures; so as to facilitate the docking of the Y-shaped insert 42, the Y-shaped limiting block 47 and the Y-shaped docking groove 241.

[0034] The mounting frame 1 has two lifting cylinders 11 fixedly installed on it to control the lifting and lowering of the knife holder 2. The output ends of the two lifting cylinders 11 are fixedly installed with lifting piston rods 12. The bottom of the two lifting piston rods 12 are detachably connected to the upper ends of the two support plates 14 respectively. The lifting cylinders 11 control the extension and retraction of the lifting piston rods 12, control the lifting and lowering of the support plates 14, and thus control the lifting and lowering of the hot pressing plate 22 on the knife holder 2 to hot press the plastic bag substrate.

[0035] Furthermore, a horizontal plate 13 is fixedly installed at the bottom of each of the two lifting piston rods 12, and a strip-shaped opening 131 is provided on the horizontal plate 13. A fastening bolt 16 is threadedly connected to the support plate 14, and the end of the fastening bolt 16 passes through the strip-shaped opening 131 and abuts against the upper side wall of the horizontal plate 13. The fastening bolt 16 and the strip-shaped opening 131 are slidably engaged to realize the relative position adjustment of the support plate 14 and the horizontal plate 13. Through the sliding engagement of the strip-shaped opening 131 on the horizontal plate 13 and the fastening bolt 16, the lateral position of the support plate 14 and the horizontal plate 13 can be adjusted. After loosening the fastening bolt 16, the support plate 14 can slide horizontally along the length direction (lateral) of the strip-shaped opening 131, which makes it easy to put the support cylinder 15 on the rotating shaft 24, reducing the assembly difficulty. At the same time, the lateral position of the hot press plate 22 can be finely adjusted to improve the applicability of the device.

[0036] The circuits and controls involved in this utility model are all existing technologies, and will not be described in detail here.

[0037] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A thermoforming machine for seamless plastic bags, comprising a mounting frame (1) installed on the frame of the thermoforming machine, characterized in that: The mounting bracket (1) is equipped with a tool holder (2) that can rotate and adjust around its own axis. Three sets of ring-shaped mounting plates (21) are fixedly installed on the tool holder (2). Between each set of two mounting plates (21), a hot press plate (22) and two electric heating plates (23) are installed. Conductive posts (231) are installed at both ends of the electric heating plates (23). Rotating shafts (24) are fixedly installed at both ends of the tool holder (2). Sleeves (3) are fitted on both rotating shafts (24) and rotatedly connected to them. The side wall of the sleeves (3) is provided for the conductive posts (231) to follow the tool. The frame (2) passes through an arc-shaped groove (32) when rotating. An installation groove (33) is provided on the inner wall of the arc-shaped groove (32), and a slider (35) is slidably connected in the installation groove (33). A spring (36) is installed in the installation groove (33), and the two ends of the spring (36) abut against the bottom of the installation groove (33) and the end of the slider (35) respectively. A conductive block (34) is installed in the arc-shaped groove (32) and is fixedly connected to the slider (35). The conductive block (34) abuts tightly against the conductive post (231) on the two heating plates (23) directly below. Support cylinders (15) are also sleeved on the two rotating shafts (24). A support plate (14) that can be raised and lowered in the vertical direction is fixedly installed on the outer circumferential surface of the support cylinder (15). A fixing plate (31) that is fixedly connected to the sleeve (3) is mounted on the support plate (14).

2. The thermoforming machine for seamless plastic bags according to claim 1, characterized in that, Two lifting cylinders (11) for controlling the lifting of the tool holder (2) are fixedly installed on the mounting bracket (1), and lifting piston rods (12) are fixedly installed at the output ends of the two lifting cylinders (11). The bottom of the two lifting piston rods (12) are detachably connected to the upper ends of the two support plates (14).

3. The thermoforming machine for seamless plastic bags according to claim 2, characterized in that, Both of the lifting piston rods (12) are fixedly mounted with a horizontal plate (13) at their bottoms, and the horizontal plate (13) has a strip-shaped opening (131). The support plate (14) is threaded with a fastening bolt (16), and the end of the fastening bolt (16) passes through the strip-shaped opening (131) and abuts against the upper side wall of the horizontal plate (13). The fastening bolt (16) and the strip-shaped opening (131) are slidably engaged to realize the relative position adjustment of the support plate (14) and the horizontal plate (13).

4. The thermoforming machine for seamless plastic bags according to claim 1, characterized in that, Both ends of the two rotating shafts (24) that are far apart from each other are provided with a chamfered structure.

5. The thermoforming machine for seamless plastic bags according to claim 1, characterized in that, The conductive block (34) has an arc-shaped structure and is located inside the arc-shaped groove (32). Both ends of the conductive block (34) are provided with arc-shaped steps, and the curvature of the arc-shaped steps is adapted to the curvature of the outer circumference of the conductive column (231).

6. The thermoforming machine for seamless plastic bags according to claim 1, characterized in that, Both of the two shafts (24) have Y-shaped docking grooves (241) at their ends. A connecting frame (4) is fixedly installed on one side of one of the support plates (14). A drive motor (41) is fixedly installed on the connecting frame (4), and a Y-shaped plug (42) inserted into the Y-shaped docking groove (241) is fixedly installed at the output end of the drive motor (41).

7. The thermoforming machine for seamless plastic bags according to claim 6, characterized in that, A connecting frame (4) is also fixedly installed on one side of the other support plate (14). An installation cylinder (44) is fixedly installed on the connecting frame (4), and a limit cylinder (45) is fixedly installed on the installation cylinder (44). A limit piston rod (46) is fixedly installed at the output end of the limit cylinder (45). A Y-shaped limit block (47) is fixedly installed at the end of the limit piston rod (46). A Y-shaped groove (43) is opened on the connecting frame (4), and the Y-shaped limit block (47) passes through the Y-shaped groove (43) and its end is inserted into the Y-shaped docking groove (241).

8. The thermoforming machine for seamless plastic bags according to claim 7, characterized in that, The opening of the Y-shaped docking groove (241) is provided with a chamfered structure, and the end of the Y-shaped insert (42) away from the drive motor (41) and the end of the Y-shaped limiting block (47) away from the limiting piston rod (46) are both provided with chamfered structures.

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