Heating structure for film blowing machine

Abstract

The utility model belongs to the technical field of film blowing machines, and particularly relates to a heating structure for a film blowing machine, which comprises a melt pipe, an induction heating coil is arranged outside the melt pipe, an electromagnetic induction heater is arranged at the extension end of the induction heating coil, a partition plate is arranged inside the top end of the melt pipe, and the electromagnetic induction heater is arranged inside the melt pipe. A gas conveying structure is arranged at the top end of the melt pipe, a partition plate is arranged at the top end of the melt pipe, a liftable material guide pipe is inserted in the middle of the partition plate, a gas inlet pipe is arranged in the material guide pipe, and the top end of the gas inlet pipe is connected with a conveying pipe. Plastic in the feeding hopper is guided into the material melting pipe through the material guiding pipe, the air inlet pipe is arranged in the material guiding pipe and extends into the material melting pipe, air is input into the material melting pipe, the liquid plastic in the material melting pipe can be pushed downwards, the descending speed of the liquid plastic is increased, and the material supplying efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of blown film machine technology, and in particular to a heating structure for blown film machines. Background Technology

[0002] A blown film machine is a specialized piece of equipment that heats and melts plastic particles and blows them into a thin film. The principle is to melt the plastic particles through an extruder, extrude them into a tubular blank through a die, and then blow them into shape with compressed air. After cooling, a thin film is formed.

[0003] Existing blown film machines mainly consist of an extruder system, a die system, a cooling device, and a traction mechanism. At the feed end of the extruder system, feed is typically delivered through an open feed hopper. A plastic granule heating device connects the feed hopper to the extrusion barrel. This heating device primarily uses electric heating elements and resistance heating to heat the feed pipe, thereby heating the plastic granules inside the feed pipe, ultimately producing molten liquid plastic. This liquid plastic flows into the extrusion barrel and is extruded into the die system. However, after the feed is heated, the liquid plastic flows downwards in the feed hopper due to the pressure of the plastic granules. Because of the viscosity of the liquid plastic, its movement down the heating device's pipes into the extrusion barrel is very slow, ultimately resulting in low feeding efficiency of the extruder system. Utility Model Content

[0004] This invention proposes a heating structure for a blown film machine to solve the problem that the process of liquid plastic moving slowly down the pipe of the heating device into the extrusion barrel is slow, which affects the feeding efficiency.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A heating structure for a blown film machine includes a melting tube, an induction heating coil disposed on the outside of the melting tube, an electromagnetic induction heater disposed on the extended end of the induction heating coil, a feed hopper connected to the top of the melting tube, a partition disposed inside the top of the melting tube, a liftable guide tube inserted in the middle of the partition, a plurality of discharge holes opened on the outer wall of the bottom end of the guide tube, an air inlet pipe disposed inside the guide tube, and a conveying pipe connected to the top of the air inlet pipe.

[0007] Preferably, the top extension end of the feed tube is connected to an installation plate, a telescopic device is provided at the bottom of one end of the installation plate, a support frame is fixed at the bottom of the telescopic device, and a guide rod is provided between the top of the support frame and the installation plate.

[0008] Preferably, a guide plate is provided below the discharge port at the bottom of the molten material tube, an installation column is fixed at the bottom of the guide plate, multiple horizontal plates are provided on the outer wall of the installation column, a spring is provided at the top of each horizontal plate, and a fixing ring is also provided at the bottom of the molten material tube, with the top extension end of the spring fixedly connected to the fixing ring.

[0009] Preferably, a sealing ring is provided on the top of the partition.

[0010] Preferably, the bottom end of the melting tube is connected to an outer cylinder, the bottom end of the outer cylinder is connected to a discharge pipe, the bottom end of the discharge pipe is connected to a feed pipe, and the bottom end of the feed pipe is fixed with a screw.

[0011] Preferably, a main flange is provided at the bottom end of the feed hopper and the bottom end of the discharge pipe, and a secondary flange is provided at the top end of the melting pipe and the feed pipe.

[0012] Preferably, the extension end of the conveying pipe is connected to a tee pipe.

[0013] Preferably, a heat insulation plate is provided on the outside of the induction heating coil, and a protective cover is provided on the outside of the heat insulation plate.

[0014] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0015] By installing a gas conveying structure at the top of the melting tube and a baffle plate at the top of the melting tube, the guide pipe of the gas conveying structure is inserted into the middle of the baffle plate. The guide pipe guides the plastic in the feed hopper into the melting tube. An air inlet pipe is installed inside the guide pipe and extends into the melting tube. By inputting gas into the melting tube, it is beneficial to push the liquid plastic in the melting tube downward, thereby increasing the descent speed of the liquid plastic and improving the feeding efficiency. This, in turn, helps the extruder system to continuously supply liquid plastic to the die head system of the blown film machine, avoiding the problem of poor quality of finished plastic film caused by raw material interruption. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the heating mechanism and the material guiding mechanism of this utility model;

[0019] Figure 3 This is a schematic diagram of the feeding device of this utility model;

[0020] Figure 4 for Figure 3 Enlarged view of section A in the middle;

[0021] Figure 5 This is a cross-sectional view of the melting tube of this utility model;

[0022] Figure 6 for Figure 5 Enlarged view of section B;

[0023] Figure 7 This is a schematic diagram of the structure of the guide tray of this utility model;

[0024] Figure 8 This is a diagram showing the protective cover of this utility model after it has been opened.

[0025] Figure 9 This is an exploded view of the material guiding mechanism of this utility model;

[0026] Figure 10 This is a schematic diagram of the gas delivery mechanism of this utility model.

[0027] In the diagram: 1. Electromagnetic induction heater; 2. Feed hopper; 3. Support frame; 4. Screw barrel; 5. Discharge pipe; 6. Feed pipe; 7. Main flange; 8. Outer cylinder; 9. Secondary flange; 10. Protective cover; 11. Guide pipe; 12. Conveying pipe; 121. T-pipe; 122. Air inlet pipe; 13. Mounting plate; 14. Induction heating coil; 15. Melting pipe; 16. Sealing ring; 17. Discharge hole; 18. Partition plate; 19. Fixing ring; 20. Guide plate; 21. Spring; 22. Horizontal plate; 23. Mounting column; 24. Heat insulation plate; 25. Telescopic device; 26. Guide rod. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] This utility model provides, for example Figure 1 - Figure 10The diagram shows a heating structure for a blown film machine. This heating structure is crucial for ensuring the uniform melting of the plastic raw material. The heating structure heats the plastic raw material into a liquid state and conveys it downwards to the extruder system of the blown film machine. The extruder system pushes the liquid plastic into the die head system of the blown film machine. The extruder system is the screw plastic extruder in the prior art. The die head system is located at the end of the screw barrel 4 of the screw plastic extruder. The liquid plastic is extruded by the screw plastic extruder into the die head system, which is the film forming structure of the blown film machine. Specific structures are disclosed in the prior art and will not be described in detail here.

[0030] The heating structure of the blown film machine of this utility model includes a melting tube 15, an induction heating coil 14 is provided on the outside of the melting tube 15, an electromagnetic induction heater 1 is provided on the extended end of the induction heating coil 14, the electromagnetic induction heater 1 and the induction heating coil 14 constitute the heating mechanism, the top end of the melting tube 15 is connected to the feed hopper 2, a partition 18 is provided inside the top end of the melting tube 15, and a sealing ring 16 is provided on the top of the partition 18. The sealing ring 16 helps to separate the feed hopper 2 from the melting tube 15, avoid gas crossflow, and thus reduce the impact of gas flow on the granular plastic inside the feed hopper 2.

[0031] A liftable guide pipe 11 is inserted in the middle of the partition 18. Several discharge holes 17 are opened on the outer wall of the bottom end of the guide pipe 11. An air inlet pipe 122 is installed inside the guide pipe 11. The bottom end of the air inlet pipe 122 passes through the partition 18 and is located inside the melting pipe 15. The top end of the air inlet pipe 122 is connected to a conveying pipe 12. The extension end of the conveying pipe 12 is connected to a three-way pipe 121. An external air pump can be connected to the end of the conveying pipe 12 through the three-way pipe 121. Gas is input into the conveying pipe 12 through the air pump. The gas enters the air inlet pipe 122 and is then conveyed downward to the melting pipe 15. The melting pipe 15 is under negative pressure. During the feeding process, plastic granules are poured into the feed hopper 2. The plastic granules reach the bottom of the feed hopper 2 and enter the interlayer between the guide pipe 11 and the air inlet pipe 122 through the discharge holes 17. Finally, they fall downward into the melting pipe 15 under the action of gravity.

[0032] It should be noted that this application is based on Faraday's law of electromagnetic induction and Joule's law, utilizing the technology of generating eddy currents in a conductor using an electromagnetic field and converting them into heat energy. The melting tube 15 is a metal tube. When the electromagnetic induction heater 1 is activated, the induction heating coil 14 is energized to heat the melting tube 15. The plastic particles inside the melting tube 15 melt due to the temperature. The electromagnetic induction heating is highly efficient and can quickly heat the melting tube 15, so that the plastic particles inside the melting tube 15 are quickly melted into a liquid state.

[0033] Because the melting tube 15 is under negative pressure, the liquid plastic is pressed downward and pushed further downward, which helps to accelerate the flow rate of the liquid plastic and thus improve the feeding efficiency of the blown film machine.

[0034] like Figure 1 - Figure 4 As shown, the top extension end of the guide tube 11 is connected to the mounting plate 13. A telescopic device 25 is provided at the bottom of one end of the mounting plate 13. A support frame 3 is fixed at the bottom of the telescopic device 25. A guide rod 26 is provided between the top of the support frame 3 and the mounting plate 13. The guide rod 26 has the characteristic of high vertical movement stability, which is conducive to keeping the mounting plate 13 stable and not shaking. The telescopic device 25 drives the mounting plate 13 to move downward and drives the guide tube 11 to move downward. The discharge hole 17 of the guide tube 11 moves down into the melting tube 15. At this time, the gas inside the melting tube 15 will not flow back to the discharge hole 17 and then enter the feed hopper 2, and will not blow the plastic particles in the feed hopper 2 upward. This further increases the gas pressure inside the melting tube 15, and the liquid plastic flows downward faster.

[0035] The telescopic device 25 returns to its original state, the support frame 3 moves upward and drives the guide pipe 11 and the air inlet pipe 122 to move upward to their original positions (at this time, the discharge hole 17 is located in the feed hopper 2).

[0036] The conveying pipe 12 and the air inlet pipe 122 form a gas conveying assembly, and the support frame 3, the telescopic device 25, the mounting plate 13, the guide pipe 11, the conveying pipe 12 and the air inlet pipe 122 form a gas conveying mechanism.

[0037] like Figure 5 - Figure 7 As shown, a guide plate 20 is provided below the discharge port at the bottom of the melting tube 15. A mounting post 23 is fixed to the bottom of the guide plate 20. Multiple horizontal plates 22 are provided on the outer wall of the mounting post 23. A spring 21 is provided on the top of each horizontal plate 22. A fixing ring 19 is also provided at the bottom of the melting tube 15. The top extension of the spring 21 is fixedly connected to the fixing ring 19. Plastic particles fall into the interior of the melting tube 15 and land on the top of the guide plate 20. Since this application uses electromagnetic induction heating, the interior of the melting tube 15 is continuously in a high-temperature state, and its internal temperature is sufficient to quickly melt the plastic particles. The guide plate 20 has a conical structure. The liquid plastic is dispersed to the surroundings and flows downward through the guide plate 20. After gas enters the interior of the melting tube 15, the internal gas pressure of the melting tube 15 increases, and the guide plate 20 also moves downward. The spring 21 is compressed and lengthens, and the gap between the guide plate 20 and the melting tube 15 increases. The liquid plastic can pass through the guide plate 20 more quickly and flow downward.

[0038] like Figure 9As shown, the bottom end of the melting tube 15 is connected to the outer cylinder 8, the bottom end of the outer cylinder 8 is connected to the discharge pipe 5, the bottom end of the discharge pipe 5 is connected to the feed pipe 6, and the bottom end of the feed pipe 6 is fixed with the screw barrel 4. The liquid plastic flows into the outer cylinder 8 after passing through the guide plate 20, and then flows into the discharge pipe 5 through the outer cylinder 8. It flows into the feed pipe 6 in the discharge pipe 5 and finally enters the screw barrel 4. The screw barrel 4 is the plastic conveying structure of the screw plastic extruder, which can cooperate with the screw and push the liquid plastic into the film forming structure of the blown film machine.

[0039] like Figure 1 - Figure 9 As shown, a main flange 7 is provided at the bottom of the feed hopper 2 and the bottom of the discharge pipe 5, and a secondary flange 9 is provided at the top of the melting pipe 15 and the feed pipe 6. The main flange 7 at the bottom of the feed hopper 2 and the secondary flange 9 at the top of the melting pipe 15 are fixedly connected by bolts. The main flange 7 at the bottom of the discharge pipe 5 and the secondary flange 9 at the top of the feed pipe 6 are fixedly connected by bolts. The feed hopper 2, the guide pipe 11, and the melting pipe 15 constitute a feeding device, which is used to introduce granular plastic into the melting pipe 15 for heating and reaching a molten state. The feed hopper 2, the melting pipe 15, the outer cylinder 8, and the discharge pipe 5 constitute a guiding mechanism, which is used for plastic conveying, so that the raw plastic material changes from granular to liquid state and finally flows into the screw barrel 4.

[0040] like Figure 8 As shown, an insulation plate 24 is provided outside the induction heating coil 14, and a protective cover 10 is provided outside the insulation plate 24. When the induction heating coil 14 is energized, it generates heat. The heat is isolated by the insulation plate 24 and protected by the protective cover 10 to prevent personnel from touching the induction heating coil 14. The heating structure of this application adopts an external fan blowing method for heat dissipation to ensure that the equipment will not overheat and malfunction.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heating structure for a blown film machine, comprising a melt tube (15), wherein an induction heating coil (14) is disposed outside the melt tube (15), and an electromagnetic induction heater (1) is disposed at the extension end of the induction heating coil (14), characterized in that: The top end of the melting tube (15) is connected to a feeding hopper (2). A partition (18) is provided inside the top end of the melting tube (15). A liftable guide tube (11) is inserted in the middle of the partition (18). Several discharge holes (17) are opened on the outer wall of the bottom end of the guide tube (11). An air inlet pipe (122) is provided inside the guide tube (11). A conveying pipe (12) is connected to the top end of the air inlet pipe (122).

2. The heating structure for a blown film machine according to claim 1, characterized in that: The top extension end of the feed tube (11) is connected to the mounting plate (13). A telescopic device (25) is provided at the bottom of one end of the mounting plate (13). A support frame (3) is fixed at the bottom of the telescopic device (25). A guide rod (26) is provided between the top of the support frame (3) and the mounting plate (13).

3. The heating structure for a blown film machine according to claim 1, characterized in that: A guide plate (20) is provided below the discharge port at the bottom of the melting tube (15). A mounting column (23) is fixed at the bottom of the guide plate (20). Multiple horizontal plates (22) are provided on the outer wall of the mounting column (23). A spring (21) is provided at the top of each horizontal plate (22). A fixing ring (19) is also provided at the bottom of the melting tube (15). The top extension of the spring (21) is fixedly connected to the fixing ring (19).

4. The heating structure for a blown film machine according to claim 1, characterized in that: A sealing ring (16) is provided on the top of the partition (18).

5. The heating structure for a blown film machine according to claim 1, characterized in that: The bottom end of the melting tube (15) is connected to an outer cylinder (8), the bottom end of the outer cylinder (8) is connected to a discharge tube (5), the bottom end of the discharge tube (5) is connected to a feed tube (6), and the bottom end of the feed tube (6) is fixed with a screw cylinder (4).

6. The heating structure for a blown film machine according to claim 5, characterized in that: The bottom of the feed hopper (2) and the bottom of the discharge pipe (5) are provided with a main flange (7), and the top of the melting pipe (15) and the feed pipe (6) are provided with a secondary flange (9).

7. The heating structure for a blown film machine according to claim 1, characterized in that: The extension end of the delivery pipe (12) is connected to a tee pipe (121).

8. The heating structure for a blown film machine according to claim 1, characterized in that: The induction heating coil (14) is provided with a heat insulation plate (24) on the outside, and a protective cover (10) is provided on the outside of the heat insulation plate (24).

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