Efficient anti-blocking PVC buried power pipe extrusion molding equipment

Abstract

The utility model relates to the technical field of plastic pipe manufacturing equipment, specifically to high -efficient anti -blocking's PVC buried electric power pipe material extrusion forming equipment, including preplasticizing unit, extrusion unit and forming die, preplasticizing unit adopts double hetero -directional meshing screw structure, cooperate high -temperature heating layer and temperature controller, realize material full, even plasticizing, extrusion unit is composed of extrusion propeller and melt gear pump, and gear pump provides stable pressure delivery, reduces pulsation, promotes extrusion stability, the electromagnetic vibrator is evenly established to draft tube, extrusion pipe and discharge pipe, effectively prevents material bridging and blockage, and forming die adopts the cooperation structure of shunt cone and mould core, and the discharge pipe is connected with the discharge pipe through cross -fixed link of shunt cone, and the installation is firm, and the positioning is accurate, ensures that pipe material wall thickness is even, and the installation groove is established to the discharge pipe feed end, and it is convenient to dismount maintenance.

Description

Technical Field

[0001] This utility model relates to the technical field of plastic pipe manufacturing equipment, specifically a high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment. Background Technology

[0002] In existing technologies, PVC raw materials are mostly in powder or granular form, which easily leads to bridging, wall adhesion, and uneven flow during transportation and plasticizing, resulting in poor feeding and affecting extrusion stability. Traditional single-screw extruders have limited shearing action, resulting in insufficient plasticizing and the generation of unmelted particles, causing die blockage or internal defects in the pipe. At the same time, the melt is affected by temperature fluctuations and pressure pulsations during transportation, which can easily lead to uneven extrusion speed, affecting the uniformity of pipe wall thickness and surface quality.

[0003] To improve plasticizing, some equipment adopts a twin-screw pre-plasticizing structure. However, due to unreasonable screw design or insufficient temperature control accuracy, problems such as uneven mixing and local overheating decomposition still exist. In addition, the conveying path of the melt from the plasticizing zone to the mold is relatively long. If the pipeline design is unreasonable or lacks anti-clogging measures, stagnant areas are easily formed at bends and connections, leading to carbonization and blockage after long-term operation.

[0004] In terms of forming molds, the flow divider cones mostly adopt a central support structure, which lacks rigidity and is prone to displacement due to molten material impact, resulting in uneven pipe wall thickness. Traditional fixing methods are inconvenient to install and disassemble, have low maintenance efficiency, and are difficult to adapt to the needs of multi-specification production. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a highly efficient, anti-clogging PVC buried power pipe extrusion molding equipment.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides the following technical solution: A high-efficiency, anti-clogging PVC buried power pipe extrusion molding equipment includes a pre-plasticizing unit, an extrusion unit, and a molding die connected sequentially. The pre-plasticizing unit includes a plasticizing tank, two extrusion screws, and a drive motor. The plasticizing tank is equipped with a high-temperature heating layer. The drive motor is fixedly installed at the end of the plasticizing tank, and its output end is connected to the extrusion screws. A feed hopper is provided at the top of the plasticizing tank. The extrusion unit includes an extrusion tank, an extrusion propeller, an extrusion motor, and a melt gear pump. The extrusion motor is installed at the end of the extrusion tank. The extrusion propeller is rotatably mounted inside the extrusion barrel via bearings. The output end of the extrusion motor is connected to the extrusion propeller via a drive. The extrusion barrel and the plasticizing barrel are connected via a guide pipe. The extrusion barrel is provided with a heat insulation layer. The extrusion barrel and the melt gear pump are connected via an extrusion pipe. A pressure sensor is installed on the extrusion pipe. The molding die includes an outlet pipe, a mold core, and a flow divider cone. The bottom of the outlet pipe is provided with a base. The output end of the melt gear pump is connected to the outlet via a flange. The flow divider cone is located at one end of the mold core. The inner diameter end of the flow divider cone is fixedly installed on the outlet pipe. A cavity is provided between the flow divider cone and the outlet of the outlet pipe.

[0009] Preferably, the two extrusion screws adopt an anti-rotating twin-screw structure, and the extrusion screw includes a feeding section, a compression section and a melting section.

[0010] More preferably, the heat insulation and heating layer and the spiral heating tube inside the heat insulation layer are provided, and the plasticizing barrel and the extrusion barrel are equipped with a temperature controller, and the temperature controller is electrically connected to the spiral heating tube.

[0011] Preferably, electromagnetic vibrators are installed on the guide pipe, extrusion pipe, and discharge pipe.

[0012] Preferably, the inner diameter end of the diverting cone is provided with a cross-shaped fixing rod, the center of which is welded to the diverting cone via a connecting rod, and the side of which is connected to the inlet end of the discharge pipe.

[0013] More preferably, the inlet end of the discharge pipe is provided with a mounting groove, and the side of the cross-shaped fixing rod is connected to the mounting groove by a through fixing screw.

[0014] (III) Beneficial Effects

[0015] Compared with the prior art, this utility model provides a high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment, which has the following beneficial effects:

[0016] The pre-plasticizing unit of this technical solution adopts a dual-opposing-meshing screw structure, which achieves efficient shearing and mixing under the drive of a motor. Combined with a high-temperature heating layer and temperature controller, it ensures that the PVC material is fully plasticized and the temperature is controllable. The extrusion unit works in conjunction with an extrusion propeller and a melt gear pump. The gear pump provides a stable melt delivery pressure with minimal pulsation, avoiding uneven flow or backflow caused by pressure fluctuations and significantly reducing the risk of blockage. The extrusion tank is equipped with an insulation layer and spiral heating tubes to maintain a stable melt temperature and prevent cooling and solidification.

[0017] The equipment is equipped with electromagnetic vibrators on the guide pipe, extrusion pipe, and discharge pipe, which can effectively prevent powder or melt from bridging, sticking to the wall, or stagnating in the pipeline, further improving the smoothness of conveying. The forming die adopts a structure that combines a flow divider cone and a die core. The cross fixing rod is connected to the discharge pipe through the mounting groove, ensuring accurate positioning and firm installation of the flow divider cone, reducing the phenomenon of misalignment, and ensuring uniform pipe wall thickness.

[0018] The entire equipment achieves continuous and stable extrusion from pre-plasticization to molding, with a high degree of automation and reliable operation. It significantly improves the surface quality of pipes and production efficiency, and is suitable for high-quality continuous production of large-diameter, long-cycle PVC power pipes. Attached Figure Description

[0019] Figure 1 This is a top view of the plasticizing cylinder end of the overall equipment of this utility model;

[0020] Figure 2 This is a top view of the molding die end of the overall equipment of this utility model;

[0021] Figure 3 This is a schematic diagram of the cross-sectional structure of the plasticizing cylinder of this utility model;

[0022] Figure 4 This is a schematic diagram of the cross-sectional structure of the extrusion cylinder of this utility model;

[0023] Figure 5 This is a schematic diagram of the cross-sectional structure of the discharge pipe of this utility model;

[0024] Figure 6 This is a schematic diagram of the extrusion screw structure of this utility model;

[0025] In the diagram: 1. Plasticizing tank; 2. Extrusion tank; 3. Melt gear pump; 4. Feed hopper; 5. Guide pipe; 6. Extrusion pipe; 7. Discharge pipe; 8. Drive motor; 9. Extrusion screw; 10. Extrusion propeller; 11. Extrusion motor; 12. Pressure sensor; 13. Mold core; 14. Diverter cone; 15. Cross-shaped fixing rod; 16. Temperature controller; 17. Spiral heating tube; 18. Electromagnetic vibrator; 19. Feeding section; 20. Compression section; 21. Melting section; 22. Connecting rod; 23. High-temperature heating layer; 24. Insulation layer; 25. Base. Detailed Implementation

[0026] 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.

[0027] Please see Figure 1-6 This utility model discloses a high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment, comprising a pre-plasticizing unit, an extrusion unit, and a molding die connected in sequence. The pre-plasticizing unit includes a plasticizing tank 1, two extrusion screws 9, and a drive motor 8. The plasticizing tank 1 is provided with a high-temperature heating layer 23. The drive motor 8 is fixedly installed at the end of the plasticizing tank 1, and the output end of the drive motor 8 is connected to the extrusion screws 9 for transmission. A feed hopper 4 is provided at the top of the plasticizing tank 1. The extrusion unit includes an extrusion tank 2, an extrusion propeller, an extrusion motor, and a melt gear pump 3. The extrusion motor is installed at the end of the extrusion tank 2, and the extrusion propeller is rotatably installed inside the extrusion tank 2 via bearings. The extrusion motor output is connected to the extrusion propeller 10. The extrusion barrel 2 and the plasticizing barrel 1 are connected by a guide pipe 5. The extrusion barrel 2 is provided with a heat insulation layer 24. The extrusion barrel 2 and the melt gear pump 3 are connected by an extrusion pipe 6. The extrusion pipe 6 is provided with a pressure sensor 12. The molding die includes a discharge pipe 7, a mold core 13 and a flow divider cone 14. The bottom of the discharge pipe 7 is provided with a base 25. The output end of the melt gear pump 3 is connected to the discharge pipe through a flange. The flow divider cone 14 is located at one end of the mold core 13. The inner diameter end of the flow divider cone 14 is fixedly installed on the discharge pipe 7. A cavity is provided between the flow divider cone 14 and the outlet of the discharge pipe 7.

[0028] This technical solution achieves progressive melting and plasticization of PVC raw materials through a twin-screw pre-plasticization unit, utilizing the shearing and temperature control synergistic effect of the counter-rotating twin screws to avoid localized scorching. The extrusion unit relies on a composite structure of an extrusion propeller and a melt gear pump to stabilize melt pressure and eliminate molding defects caused by fluctuations. The molding die achieves pipe forming through the precise cooperation of the flow divider cone 14 and the die core 13, while integrating multi-dimensional anti-clogging design, vibration, temperature control, and structural optimization to eliminate the risk of blockage. Finally, through the coordinated linkage of each unit, the solution addresses the pain points of traditional equipment, such as uneven plasticization, large pressure fluctuations, easy blockage, and low molding accuracy, achieving efficient, low-loss, and continuous production of PVC power pipes with diameters of 50-300mm.

[0029] The pre-plasticizing unit is the core step in raw material melting. It achieves efficient plasticizing and anti-clogging through counter-rotating twin screws, a high-temperature heating layer 23, and structural optimization. The working principles of each component are as follows:

[0030] The two extrusion screws 9 of the counter-rotating twin-screw structure adopt a counter-rotating design, and the screw edges have an uneven pitch and varying depth structure, including the feed section 19, the compression section 20 and the melting section 21:

[0031] Feeding section 19: The large screw pitch design increases the feeding volume. After the PVC mixed raw material enters from the feeding hopper 4, it is synchronously conveyed to the compression section 20 by the twin screws to avoid the accumulation of raw materials and blockage of the feeding port.

[0032] Compression section 20: The screw channel volume gradually decreases, squeezing and compacting the raw material, expelling air from the raw material and reducing air bubble defects in the pipe. At the same time, the shearing action between the extrusion screw 9 and the inner wall of the plasticizing tank 1 initially breaks down the raw material agglomerates.

[0033] Melting section 21: The minimum pitch design enhances shear force, and combined with the heat of the high-temperature heating layer 23, it enables the raw material to gradually transform from solid particles to molten melt. The anti-interlocking structure can prevent the melt from stagnating in the screw channel and reduce the probability of coking.

[0034] Compared to traditional single-screw extruders, counter-rotating twin-screw extruders improve plasticizing efficiency by 40% and calcium carbonate filler dispersion uniformity by 30%, effectively reducing barrel blockage caused by filler agglomeration.

[0035] Spiral heating tube 17 heating: The high-temperature heating layer 23 of the plasticizing tank 1 has a built-in spiral heating tube 17. The heating tube is spirally attached to the inner wall of the plasticizing tank 1, so that the heat is evenly transferred to the box and local overheating is avoided.

[0036] Temperature controller 16 provides precise control: The temperature controller 16 on the plasticizing tank 1 collects the temperature inside the tank in real time and adjusts the heating power of the spiral heating tube 17 through a PID algorithm to achieve three-stage temperature control. For example, the temperature of the spiral heating tube 17 at the feeding section 19 is 140-160℃: softening the raw material; the temperature of the spiral heating tube 17 at the compression section 20 is 160-170℃: initial melting; and the temperature of the spiral heating tube 17 at the melting section 21 is 170-180℃: complete plasticization.

[0037] This design can dynamically adjust the temperature according to the melting characteristics of PVC raw materials, avoiding incomplete plasticization due to excessively low temperature or scorching due to excessively high temperature.

[0038] Drive motor 8 is preferably a servo motor, connected to a twin-screw drive via a coupling. The motor speed can be adjusted in real time via a PLC controller.

[0039] The motor runs at a constant speed, extending the residence time of the melt in the melting section 21 to ensure thorough plasticization.

[0040] The extrusion unit receives the molten material from the pre-plasticization unit and achieves stable extrusion through screw conveying, gear pump pressure stabilization, and vibration anti-clogging. The working principles of each component are as follows:

[0041] The extrusion propeller and extrusion motor: The extrusion propeller is rotatably mounted inside the extrusion barrel 2 via bearings. The extrusion motor, preferably a servo motor, is connected to the propeller via a gearbox.

[0042] Material conveying: After the molten material enters the extrusion barrel 2 from the guide pipe 5, the extrusion propeller pushes the material towards the melt gear pump through the screw ribs. The screw groove depth is preferably designed to be gradual to compact the melt and discharge residual air.

[0043] A pressure-stabilizing melt gear pump is installed between the extrusion barrel 2 and the forming die, and is connected through the extrusion pipe 6.

[0044] Stable pressure: The melt pressure fluctuation of traditional single-screw extrusion can reach ±0.5MPa, resulting in pipe wall thickness deviation exceeding ±5%; the melt gear pump controls the melt pressure fluctuation within ±0.1MPa through the volumetric delivery of a pair of meshing gears, ensuring uniform melt flow into the molding die.

[0045] Anti-backflow function: The gear pump has excellent reverse sealing performance, which can prevent the melt in the molding die from flowing back into the extrusion tank 2 due to pressure changes, thus avoiding blockage caused by material retention and deterioration.

[0046] The insulation layer 24 of the extrusion barrel 2 can reduce the heat loss of the melt in the extrusion barrel 2 and avoid the increase in viscosity of the melt due to a sudden drop in temperature; the spiral heating tube 17 in the insulation layer 24 can assist in heat supplementation to ensure that the melt temperature is stable at 170-180℃.

[0047] The electromagnetic vibrator 18 on the guide tube 5 and the extrusion tube 6, after the vibrator is started, causes the melt adhering to the inner wall of the tube to fall off through high-frequency micro-vibration, which can improve the melt flowability, reduce the retention of material, and break the blockage in the tube.

[0048] The forming mold is crucial for the final forming of the pipe. Through flow diversion and guidance, and optimized structure for easy maintenance, it achieves precise forming and anti-clogging. The working principles of each component are as follows:

[0049] The flow divider cone 14 is located at the feed end of the mold core 13 and has a conical structure. Its function is to divide the melt entering from the discharge pipe 7 into a ring. The melt is evenly distributed along the cone surface of the flow divider cone 14 to the cavity between the mold core 13 and the discharge pipe 7, so as to avoid the melt directly impacting the mold core 13 and causing the local flow rate to be too fast.

[0050] Positioning of cross-shaped fixing rod 15: The inner diameter end of the diversion cone 14 is connected to the discharge pipe 7 through the cross-shaped fixing rod 15. The center of the cross-shaped fixing rod 15 is welded to the diversion cone 14 through the connecting rod 22, and the side is connected to the installation groove of the discharge pipe 7 through fixing screws, so as to ensure that the diversion cone 14 does not shift under the impact of high pressure melt and ensure that the pipe wall thickness is uniform.

[0051] An annular cavity is formed between the discharge pipe 7 and the mold core 13. The size of the cavity determines the wall thickness of the pipe. For example, if a pipe with a diameter of 200mm and a wall thickness of 5mm is produced, the cavity is set to 5mm.

[0052] The feed end of the discharge pipe 7 and the diversion cone 14 are fixedly assembled in the mounting groove by the fixing screws on the side of the cross fixing rod 15;

[0053] Quick flange removal: The melt gear pump is connected to the discharge pipe 7 via a flange. The flange sealing surface uses a heat-resistant fluororubber gasket. When blockage occurs in the discharge pipe 7, the flange can be quickly removed for cleaning, avoiding the cumbersome process of complete disassembly required by traditional integral molds, and reducing maintenance time by 60%.

[0054] Detailed System Workflow

[0055] Device initialization and parameter setting

[0056] Temperature control system start-up: The high-temperature heating layer 23 of the pre-plasticizing unit and the insulation layer 24 of the extrusion unit are turned on. The temperature controller 16 sets the temperature as follows: the temperature of the plasticizing tank 1 corresponding to the feeding section 19 is 150℃, the temperature of the corresponding compression section 20 is 165℃, and the temperature of the corresponding melting section 21 is 175℃; the insulation temperature of the extrusion unit is 175℃.

[0057] Motor and gear pump debugging: Start drive motor 8, set the twin screw speed to 100r / min; start extrusion motor, set the extrusion propeller speed to 80r / min; start melt gear pump, set the speed to 30r / min, run unloaded for 5 minutes, and check that there are no abnormalities in each transmission component;

[0058] Anti-blocking system ready: turn on electromagnetic vibrator 18 and temperature controller 16, temperature controller 16 enters real-time monitoring state, and data is transmitted to PLC control system.

[0059] Raw material preplasticization stage

[0060] Raw material feeding: The PVC mixed raw material is fed into the plasticizing tank 1 from the feed hopper 4 of the pre-plasticizing unit;

[0061] Progressive plasticization:

[0062] The raw material enters the feeding section 19 and is rapidly conveyed to the compression section 20 by the twin screws. The screw groove volume is reduced to achieve compaction and expel air.

[0063] Upon entering the compression section 20, the raw material undergoes initial melting under shearing and heating, forming a semi-molten material.

[0064] Entering the melting section 21, it is completely plasticized into a uniform melt. The twin screw speed is preferably set at 100 r / min to ensure thorough plasticization.

[0065] Melt extrusion and pressure stabilization stage

[0066] Melt transport: The pre-plasticized melt enters the extrusion barrel 2 through the guide pipe 5. The extrusion propeller drives the melt to move towards the extrusion tube 6 at a speed of 80 r / min. The stepped screw edges of the propeller separate the unmelted hard blocks to the edge of the screw groove to prevent them from entering the subsequent stages.

[0067] Pressure stabilization: The melt enters the melt gear pump, and the melt gear pump 3 stabilizes the melt pressure at 8±0.1MPa through volumetric conveying, and then conveys it to the molding die through the extrusion pipe 6;

[0068] Anti-blockage monitoring: The pressure inside the extrusion tube 6 is detected by a pressure detector. If the pressure inside the extrusion tube 6 suddenly increases to 9MPa, the PLC immediately starts the electromagnetic vibrator 18 of the guide tube 5 and the extrusion tube 6, and at the same time reduces the speed of the drive motor 8 to 80r / min and the speed of the extrusion motor to 60r / min. The pressure drops back to 8MPa within 30 seconds and normal operation is restored.

[0069] Split molding: The melt enters the discharge pipe 7 of the molding die through the flange, and the split cone 14 splits the melt into the cavity between the mold core 13 and the discharge pipe 7 to form a tubular blank.

[0070] Anti-sticking and anti-clogging: The electromagnetic vibrator 18 of the discharge pipe 7 is activated to prevent the melt from adhering to the pipe wall and the surface of the diversion cone 14;

[0071] After the tubular blank is formed, it enters a conventional pipe cooling and shaping device in the field of plastic pipe manufacturing equipment to cool and shape it before entering the cutting step.

[0072] Regular maintenance: After each day's work, stop the machine, disassemble the mold flange and cross fixing rod 15, and introduce 0.5MPa compressed air to clean the residual melt in the discharge pipe 7 and the diverter cone 14; check the working status of the spiral heating tube 17 and the electromagnetic vibrator 18, and replace damaged parts if necessary.

[0073] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency, anti-clogging PVC buried power pipe extrusion molding equipment, characterized in that, The system includes a pre-plasticizing unit, an extrusion unit, and a molding die connected in sequence. The pre-plasticizing unit includes a plasticizing tank (1), two extrusion screws (9), and a drive motor (8). The plasticizing tank (1) is provided with a high-temperature heating layer (23). The drive motor (8) is fixedly installed at the end of the plasticizing tank (1). The output end of the drive motor (8) is connected to the extrusion screws (9) for transmission. The top of the plasticizing tank (1) is provided with a feed hopper (4). The extrusion unit includes an extrusion tank (2), an extrusion propeller, an extrusion motor, and a melt gear pump (3). The extrusion motor is installed at the end of the extrusion tank (2). The extrusion propeller is rotatably installed inside the extrusion tank (2) through bearings. The output end of the extrusion motor is connected to the extrusion propeller (10) for transmission. The extrusion barrel (2) and the plasticizing barrel (1) are connected by a guide pipe (5). The extrusion barrel (2) is provided with a heat insulation layer (24). The extrusion barrel (2) and the melt gear pump (3) are connected by an extrusion pipe (6). A pressure sensor (12) is provided on the extrusion pipe (6). The molding die includes a discharge pipe (7), a mold core (13), and a flow divider cone (14). The bottom of the discharge pipe (7) is provided with a base (25). The output end of the melt gear pump (3) is connected to the discharge pipe through a flange. The flow divider cone (14) is located at one end of the mold core (13). The inner diameter end of the flow divider cone (14) is fixedly installed on the discharge pipe (7). A cavity is provided between the flow divider cone (14) and the outlet of the discharge pipe (7).

2. The high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment according to claim 1, characterized in that, The two extrusion screws (9) adopt an opposite meshing twin-screw structure, and the extrusion screw (9) includes a feeding section (19), a compression section (20) and a melting section (21).

3. The high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment according to claim 1, characterized in that, The heat insulation heating layer and the heat insulation layer (24) are provided with a spiral heating tube (17). The plasticizing barrel (1) and the extrusion barrel (2) are equipped with a temperature controller (16), and the temperature controller (16) is electrically connected to the spiral heating tube (17).

4. The high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment according to claim 1, characterized in that, Electromagnetic vibrators (18) are installed on the guide pipe (5), extrusion pipe (6) and discharge pipe (7).

5. The high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment according to claim 1, characterized in that, The inner diameter end of the diversion cone (14) is provided with a cross-shaped fixing rod (15). The center of the cross-shaped fixing rod (15) is welded to the diversion cone (14) through a connecting rod (22). The side of the cross-shaped fixing rod (15) is connected to the feed end of the discharge pipe (7).

6. The high-efficiency anti-clogging PVC buried power pipe extrusion molding equipment according to claim 5, characterized in that, The feed end of the discharge pipe (7) is provided with a mounting groove, and the side of the cross fixing rod (15) is connected to the mounting groove by a through fixing screw.

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