Equipment and method for processing plastic pipe from waste plastic

Abstract

The invention relates to the technical field of waste plastic processing, in particular to equipment and a method for processing plastic pipes from waste plastics, comprising a cold water tank, a cooling cylinder fixedly connected to the upper end of the cold water tank, a cavity formed in the cooling cylinder, a water inlet pipe fixedly connected to the side wall of the cooling cylinder, and a plurality of drainage grooves formed in the inner wall of the cooling cylinder; the upper end of the cold water pool is connected with a forming mechanism, one end of the cooling cylinder is fixedly connected with a guide cover, the forming mechanism comprises an extrusion cylinder, an extrusion screw is rotationally connected in the extrusion cylinder, a feeding port is formed in the upper end of the extrusion cylinder, the front end of the extrusion cylinder is fixedly connected with a discharging pipe, and a forming column is fixedly connected in the discharging pipe. Cold water is discharged through the multiple drainage grooves at the same time, the surface of the pipe wall of the plastic pipe can be completely covered, and the problem that water distribution is uneven in a traditional water flow cooling mode is solved.

Description

Technical Field

[0001] This invention relates to the field of waste plastic processing technology, and in particular to an apparatus and method for processing waste plastic into plastic pipes. Background Technology

[0002] When processing plastic pipes from waste materials, workers first crush and remove impurities from the waste plastic, then mix it with additives and add it to the molding equipment. The molding equipment heats the waste plastic to a molten state, and finally extrudes the plastic into a tubular shape. After extrusion, the plastic pipe needs to be cooled and shaped. Conventional equipment involves the plastic pipe moving through a water flow, allowing the water to cover the pipe body, thus achieving the function of cooling and shaping the plastic pipe. However, this method requires multiple water flows, which prolongs the processing line and increases the cooling time of the plastic pipe; otherwise, the plastic pipe cannot be fully cooled.

[0003] Uneven cooling can lead to inconsistent curing of the pipe surface. Areas that are not fully cooled are prone to internal stress due to subsequent cooling, which can cause unevenness, pitting, or cracks on the surface. For example, water cooling can result in uneven distribution of cooling water, with more water at the top of the plastic pipe and less at the bottom. This difference in cooling rate can cause pitting on the pipe surface. On the other hand, cooling that is too fast or too insufficient can result in a rough and dull surface. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide an equipment and method for processing waste plastic into plastic pipes. In this application, cold water is discharged simultaneously through multiple drainage channels, which can fully cover the surface of the plastic pipe wall and solve the problem of uneven water distribution in traditional water cooling methods.

[0005] A device for processing waste plastic into plastic pipes includes a cold water tank, a cooling cylinder fixedly connected to the upper end of the cold water tank, a cavity inside the cooling cylinder, a water inlet pipe fixedly connected to the side wall of the cooling cylinder, and multiple drainage grooves opened on the inner wall of the cooling cylinder. The water inlet pipe and the multiple drainage grooves are all connected to the cavity, and a forming mechanism is connected to the upper end of the cold water tank.

[0006] A guide cover is fixedly connected to one end of the cooling cylinder.

[0007] The forming mechanism includes an extrusion cylinder, an extrusion screw is rotatably connected inside the extrusion cylinder, a feed port is opened at the upper end of the extrusion cylinder, a discharge pipe is fixedly connected to the front end of the extrusion cylinder, and a forming column is fixedly connected inside the discharge pipe.

[0008] A sliding cylinder is fixedly connected to the cold water tank. A sliding plug is slidably connected inside the sliding cylinder. A straight plate is fixedly connected to the upper end of the sliding plug. A water pumping pipe is fixedly connected to the lower end of the sliding cylinder. A drain pipe is fixedly connected to the sliding cylinder. A connecting pipe is fixedly connected between the drain pipe and the water inlet pipe. Valves are installed in both the water pumping pipe and the drain pipe.

[0009] A crankshaft is fixedly connected to the shaft of the extrusion screw, and a connecting rod is rotatably connected to the crankshaft. One end of the connecting rod is rotatably connected to a straight plate.

[0010] A drive motor is fixedly connected to the extrusion cylinder, and one end of the crankshaft is fixedly connected to the output shaft of the drive motor.

[0011] A connecting frame is fixedly connected to the straight plate, and two lifting plates are fixedly connected to the lower end of the connecting frame.

[0012] Both lifting platforms are V-shaped.

[0013] Both lifting platforms are inverted trapezoidal in shape. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0015] Figure 1 and Figure 2 A schematic diagram of the overall structure of a device for processing waste plastics into plastic pipes;

[0016] Figure 3 This is a schematic diagram of the guide cover structure;

[0017] Figure 4 This is a schematic diagram of the cooling cylinder structure;

[0018] Figure 5 This is a schematic diagram of the extrusion cylinder.

[0019] Figure 6 This is a schematic diagram of the extrusion screw structure;

[0020] Figure 7 This is a schematic diagram of the slide tube structure;

[0021] Figure 8 This is a schematic diagram of the lifting platform. Detailed Implementation

[0022] The present invention will be described in detail with reference to the accompanying drawings in the embodiments of the present invention.

[0023] A device for processing waste plastic into plastic pipes includes a cold water tank 306, a cooling cylinder 101 fixedly connected to the upper end of the cold water tank 306, a cavity 102 provided inside the cooling cylinder 101, a water inlet pipe 104 fixedly connected to the side wall of the cooling cylinder 101, and a plurality of drainage grooves 103 provided on the inner wall of the cooling cylinder 101. The water inlet pipe 104 and the plurality of drainage grooves 103 are all connected to the cavity 102, and a forming mechanism is connected to the upper end of the cold water tank 306.

[0024] See Figure 1-4 ,

[0025] When processing plastic pipes from waste scrap, the workers first crush and remove impurities from the waste plastic, then mix it with additives and add it to the molding mechanism. The molding mechanism heats the waste plastic to a molten state, and finally extrudes the plastic into a tubular shape. After extrusion, the plastic pipe needs to be cooled and shaped. Conventional equipment involves the plastic pipe moving through a water flow, allowing the water to cover the pipe body, thereby achieving the function of cooling and shaping the plastic pipe. However, this method requires multiple water flows, which prolongs the processing line and increases the cooling time of the plastic pipe; otherwise, the plastic pipe cannot be fully cooled.

[0026] Uneven cooling can lead to inconsistent curing of the pipe surface. Areas that are not fully cooled are prone to internal stress due to subsequent cooling, which can cause unevenness, pitting, or cracks on the surface. For example, water cooling can result in uneven distribution of cooling water, with more water at the top of the plastic pipe and less at the bottom. This difference in cooling rate can cause pitting on the pipe surface. On the other hand, cooling that is too fast or too insufficient can result in a rough and dull surface.

[0027] When using the equipment of this application, the extruded plastic tube passes through the cooling cylinder 101, the inner diameter of which is slightly larger than the diameter of the plastic tube. At this time, cold water is injected into the cavity 102 of the cooling cylinder 101 through the water inlet pipe 104. Since multiple drainage grooves 103 are radially and evenly distributed on the inner wall of the cooling cylinder 101, the cold water can be discharged simultaneously through multiple drainage grooves 103 under pressure. The discharged cold water can fully cover the surface of the plastic tube wall. After the cold water comes into contact with the tube wall, the tube wall is cooled and its temperature drops. At the same time, the cold water absorbs heat and its temperature rises, which causes the cold water around the tube wall to heat up synchronously. The water temperature around the tube wall can always be kept consistent, thereby avoiding the phenomenon of inconsistent temperature in some parts of the tube wall caused by the water cooling method, avoiding deformation or pitting, and further improving the overall quality of the plastic tube.

[0028] This application features multiple drainage channels 103 evenly distributed radially. Cold water is discharged simultaneously through these channels, fully covering the surface of the plastic pipe wall. This solves the problem of uneven cooling of the pipe wall caused by uneven water distribution in traditional water cooling methods, such as a large amount of water at the top of the plastic pipe and a small amount at the bottom. The water temperature around the pipe wall remains consistent, avoiding uneven solidification of the pipe wall due to excessively low temperatures in some areas, such as areas with strong water flow impact. This reduces the generation of internal stress and prevents defects such as pitting and cracks from appearing on the surface of the plastic pipe.

[0029] Cold water evenly covers the pipe wall through the drainage channel, making the cooling process gentler and avoiding problems such as rough and dull plastic pipe surface caused by excessively rapid cooling in traditional cooling methods. This improves the surface quality and overall strength of the plastic pipe. The design of the inner diameter of the cooling cylinder 101 is slightly larger than the diameter of the plastic pipe. Combined with the evenly distributed drainage channel 103, it not only ensures the smooth passage of the plastic pipe but also achieves all-round contact of the cooling water. Together with the cold water pool 306 and the inlet pipe 104, it forms a synergistic cooling system, improving cooling efficiency.

[0030] A guide cover 105 is fixedly connected to one end of the cooling cylinder 101.

[0031] See Figure 4 ,

[0032] When the plastic tube is extruded, it first passes through the guide cover 105. The guide cover 105 guides and positions the plastic tube, causing it to move along the central axis of the cooling cylinder 101. The inner wall of the guide cover 105 is provided with a rounded chamfer. This structure can effectively prevent the extruded plastic tube from bending downwards naturally due to its own weight or extrusion inertia, ensuring that the plastic tube completes the cooling and shaping process in a straight state. The guide cover 105 uses its cylindrical structure to initially position the freshly extruded plastic tube, limiting its radial sway and preventing the plastic tube from colliding with the inner wall of the cooling cylinder 101 due to positional deviation when entering the cooling cylinder 101. This reduces the risk of scratches or deformation on the tube surface and ensures the integrity of the tube's shape.

[0033] The rounded chamfer design of the inner wall of the guide cover 105 eliminates the sharp contact points between the plastic tube and the inner wall of the guide cover, reducing the local stress concentration of the plastic tube when it passes through. At the same time, the rounded transition guides the plastic tube to move naturally along the central axis, counteracting the downward bending tendency of the plastic tube caused by its own weight, keeping the plastic tube in a straight line motion state, and avoiding uneven wall thickness or surface ripple defects caused by bending.

[0034] The plastic pipe passes through the cooling cylinder 101 in a straight position, which allows the cooling water to be evenly covered on the pipe wall surface through the drainage groove 103. This avoids over-cooling in some areas, such as the inside of the bend, or under-cooling, such as the outside of the bend, caused by pipe bending. This ensures the overall consistency of pipe cooling, further improves the cooling and shaping effect, and reduces residual internal stress.

[0035] The forming mechanism includes an extrusion cylinder 201, an extrusion screw 202 is rotatably connected inside the extrusion cylinder 201, a feed port 205 is opened at the upper end of the extrusion cylinder 201, a discharge pipe 203 is fixedly connected to the front end of the extrusion cylinder 201, and a forming column 204 is fixedly connected inside the discharge pipe 203.

[0036] See Figure 5-6 ,

[0037] Waste plastic is crushed and impurities removed, then mixed with additives and added to the extrusion cylinder 201 through the feed inlet 205. The extrusion cylinder 201 is connected to an external heating device to heat the waste plastic. At the same time, the extrusion screw 202 is controlled to convey the plastic forward, thus pushing the molten plastic forward. Finally, it is extruded in a tubular shape through the gap between the discharge pipe 203 and the forming column 204 to form a plastic tube.

[0038] A sliding cylinder 305 is fixedly connected to the cold water tank 306. A sliding plug 304 is slidably connected inside the sliding cylinder 305. A straight plate 303 is fixedly connected to the upper end of the sliding plug 304. A water pumping pipe 306 is fixedly connected to the lower end of the sliding cylinder 305. A drain pipe 404 is fixedly connected to the sliding cylinder 305. A connecting pipe 404 is fixedly connected between the drain pipe 404 and the water inlet pipe 104. Valves are installed inside both the water pumping pipe 306 and the drain pipe 404.

[0039] See Figure 7 ,

[0040] During the cooling process of the plastic pipe, the operator controls the sliding stopper 304 to slide upwards. At this time, a negative pressure is generated inside the sliding cylinder 305, the one-way valve in the water suction pipe 306 opens, and the one-way valve in the drain pipe 404 closes. This allows cold water to be drawn from the cold water pool 306 through the water suction pipe 306. Then, the operator controls the sliding stopper 304 to slide downwards, increasing the pressure inside the sliding cylinder 305. At this time, the one-way valve in the water suction pipe 306 closes, and the one-way valve in the drain pipe 404 opens. The cold water in the sliding cylinder 305 then enters the connecting pipe 404 through the drain pipe 404, and then enters the cooling cylinder 101 through the connecting pipe 404, thus achieving the function of cooling the plastic pipe.

[0041] The cold water discharged from multiple drainage channels 103 can be returned to the cold water pool 306, realizing the function of cold water recycling.

[0042] This application utilizes the reciprocating sliding of the sliding plug 304 within the sliding cylinder 305 to precisely adjust the water pumping volume of the pumping pipe 306 and the drainage volume of the drain pipe 404. Combined with the limiting effect of the straight plate 303 on the sliding plug 304, it prevents water pressure fluctuations caused by excessive sliding of the sliding plug 304, ensuring that the coolant enters the cooling cylinder 101 at a stable flow rate. This provides a uniform and continuous cooling medium for the plastic pipe, improving the stability of the cooling effect. The warm water in the cooling cylinder 101, after heat exchange, flows back to the cold water pool 306 through multiple drainage channels 103, achieving a closed-loop circulation of cooling water. This reduces the frequency and amount of fresh cooling water replenishment, lowers water consumption, meets environmental protection production requirements, and is particularly suitable for water-saving scenarios in large-scale plastic pipe production.

[0043] The fixed connection between the sliding plug 304 and the straight plate 303 allows the operator to push the straight plate 303 to achieve synchronous sliding of the sliding plug 304, making operation more labor-saving. The one-way valve design of the water suction pipe 306 and the drain pipe 404 avoids the backflow of coolant, eliminating the need for an additional check valve, simplifying the pipeline structure and reducing equipment maintenance costs. The connecting pipe 404 connects the drain pipe 404 and the water inlet pipe 104, allowing the coolant to be directly delivered to the cooling cylinder 101, ensuring the continuity of coolant supply, avoiding uneven cooling of the plastic pipe due to coolant interruption, reducing the occurrence of defects such as pitting and cracks on the pipe surface, and improving the molding quality and appearance consistency of the plastic pipe.

[0044] A crankshaft 301 is fixedly connected to the shaft of the extrusion screw 202, and a connecting rod 302 is rotatably connected to the crankshaft 301. One end of the connecting rod 302 is rotatably connected to the straight plate 303.

[0045] See Figure 8 ,

[0046] The extrusion screw 202 rotates to extrude plastic while also driving the crankshaft 301 to rotate. The crankshaft 301 and connecting rod 302 work together to push and pull the sliding plug 304 on the straight plate 303. This allows the power of the extrusion screw 202 to achieve continuous water pumping and drainage, and to automatically cool the plastic tube. There is no need to equip a separate power source to drive the sliding plug 304, nor is there a need to control the sliding plug 304 separately. This achieves the function of synchronous control of the extrusion screw 202 and the sliding plug 304.

[0047] The extrusion screw 202, as the core power component of the plastic extruder, rotates as a necessary action to achieve plastic extrusion. By fixing the crankshaft 301 to the shaft of the extrusion screw 202, the crankshaft 301 rotates synchronously with the extrusion screw 202, converting the rotational power of the extrusion screw 202 into the rotational power of the crankshaft 301. This design avoids equipping the sliding plug 304 with a separate power source, reducing the complexity of the equipment's power system and lowering overall energy consumption. When the extrusion screw 202 rotates, the pumping and draining actions of the sliding plug 304 are performed simultaneously, requiring no additional electricity or mechanical energy consumption, thus meeting the requirements of energy-saving production.

[0048] The crankshaft 301 and connecting rod 302 work together to push and pull the sliding plug 304 on the straight plate 303. The movement of the straight plate 303 is directly related to the rotation of the extrusion screw 202 through a mechanical structure. When the extrusion screw 202 rotates, the sliding plug 304 pumps and drains water at a fixed rhythm, without the need for manual operation or a separate control system. This synchronous control method ensures close coordination between the extrusion and cooling processes, allowing the plastic tube to be cooled simultaneously with extrusion. This avoids low production efficiency caused by asynchronous extrusion and cooling, such as excessively fast extrusion without timely cooling, which could lead to deformation of the plastic tube. This improves the continuity and efficiency of the overall production process.

[0049] The mechanical structure composed of crankshaft 301, connecting rod 302, straight plate 303, and slide plug 304 is compact, with all components arranged around the shaft of extrusion screw 202, reducing the equipment's footprint. Furthermore, since there is no need to separately control the power source and operating mechanism of slide plug 304, operators only need to monitor the operating status of extrusion screw 202, reducing operational complexity. For example, in traditional equipment, a dedicated person is required to adjust the pumping frequency and drainage volume of slide plug 304, while in this design, the movement of slide plug 304 automatically adjusts with the extrusion screw 202, reducing manual intervention and lowering the labor intensity and training costs for operators.

[0050] The rotational connection between crankshaft 301 and connecting rod 302, and the rotational connection between connecting rod 302 and straight plate 303, both adopt mechanical structures, which have high stability and reliability. Compared with hydraulic or pneumatic control systems, mechanical linkage is less affected by external factors such as hydraulic oil leakage and air pressure fluctuations, and can maintain stable push-pull action for a long time, ensuring the normal operation of the pumping and draining functions of the slide plug 304. This stability reduces the probability of equipment failure, lowers maintenance costs, and ensures the stability of the cooling effect of the plastic tube. The stable action of the slide plug 304 allows cooling water to continuously and evenly enter the cooling cylinder 101, providing consistent cooling conditions for the plastic tube and avoiding quality problems of the plastic tube caused by unstable cooling.

[0051] A drive motor 403 is fixedly connected to the extrusion cylinder 201, and one end of the crankshaft 301 is fixedly connected to the output shaft of the drive motor 403.

[0052] See Figure 1 ,

[0053] The drive motor 403 drives the crankshaft 301 to rotate, and the crankshaft 301 drives the extrusion screw 202 to rotate. The drive motor 403 serves as the single drive source to realize the functions of plastic tube extrusion and plastic tube cooling.

[0054] A connecting frame 401 is fixedly connected to the straight plate 303, and two lifting plates 402 are fixedly connected to the lower end of the connecting frame 401.

[0055] See Figure 3 ,

[0056] As the straight plate 303 moves up and down, it drives the two lifting plates 402 to move up and down as well. This allows the two lifting plates 402 to move the cold water in the cold water pool 306 using the power of pumping and draining water. This causes the cold water in the cold water pool 306 to flow faster, thereby avoiding local temperature differences in the cold water in the cold water pool 306 and ensuring the cooling effect on the plastic pipe.

[0057] Both lifting platforms 402 are V-shaped.

[0058] See Figure 8 ,

[0059] The fixed connection between the straight plate 303 and the connecting frame 401 converts the up-and-down movement of the straight plate 303 into the synchronous movement of the connecting frame 401, which in turn drives the two lifting plates 402 to perform regular lifting and lowering movements. This design cleverly transforms the pumping and drainage power generated by the rotation of the extrusion screw 202 into spatial lifting and lowering motion, driving the lifting plates 402 to work without an additional power source, thus simplifying and efficiently utilizing the power system.

[0060] As the two lifting plates 402 move up and down, they continuously agitate the cold water in the cold water tank 306. The upward and downward trajectory of the lifting plates 402 creates water flow disturbance, breaking the original static state in the cold water tank and causing the cold water to circulate within the tank. This flow pattern can quickly raise the cold water at the bottom of the cold water tank to the surface, while simultaneously bringing the warm water from the surface to the bottom, promoting uniform mixing of the cold water within the tank.

[0061] The uniform flow of cold water within the cold water tank 306 effectively prevents temperature differences caused by stagnant water flow in certain areas. In traditional cold water tank designs, stagnant cold water can easily lead to lower temperatures at the bottom and higher temperatures at the surface. This localized temperature difference causes uneven cooling rates in different parts of the plastic pipe, resulting in defects such as pitting and cracks on the pipe surface. However, the water circulation driven by the lifting plate 402 ensures that the water temperature in all areas of the cold water tank is more uniform, guaranteeing the uniformity of the cooling process for the plastic pipe and improving the overall quality of the pipe.

[0062] The 402 lifting plate features a V-shaped design, further enhancing the efficiency of agitating the cold water. The tip of the V-shape can more effectively cut the water flow, reducing water flow resistance while expanding the range of cold water disturbance. Compared to a flat lifting plate, the V-shaped lifting plate can drive more cold water into circulation within the same lifting stroke, increasing the speed and range of cold water flow, thereby more effectively eliminating local temperature differences and ensuring consistent cooling performance.

[0063] Both lifting platforms 402 are inverted trapezoidal.

[0064] See Figure 8 ,

[0065] The inclined sidewall design of the inverted trapezoidal lifting plate 402 allows it to more effectively cut the water flow within the cold water tank 306 during its vertical movement. Compared to vertical or rectangular structures, the inclined surface of the inverted trapezoid reduces the resistance of the water flow to the lifting plate while expanding the disturbance range of the cold water, making it easier for the cold water to be driven to form a circulating flow.

[0066] The wide bottom design of the inverted trapezoidal lifting plate 402 increases the contact area with cold water, enabling it to more stably propel the cold water to diffuse in all directions. This structure makes the water flow distribution in the cold water pool 306 more uniform, avoiding situations where the water flow is too fast or too slow in some areas, further eliminating local temperature differences in the cold water pool, and ensuring that the cooling rate of all parts of the plastic pipe is consistent.

[0067] The inverted trapezoidal lifting plate 402 has a low center of gravity, resulting in smoother vertical movement and reducing unnecessary disturbance to the cold water in the cold water tank 306 caused by plate swaying. This stability not only improves the reliability of the cooling process but also extends the service life of the lifting plate 402, reducing equipment maintenance costs. The design of the inverted trapezoidal lifting plate 402 is compatible with the shape and size of the cold water tank 306, achieving maximum water flow disturbance within a limited space. This adaptability makes the overall equipment structure more compact while ensuring cooling efficiency, meeting the needs of large-scale plastic pipe production.

[0068] A method for processing plastic pipes using processing equipment, the method comprising the following steps:

[0069] Step 1: First, the recycled waste plastic is crushed and cleaned to remove impurities and foreign objects. Then, it is mixed evenly with additives in a certain proportion to form plastic raw materials that meet the processing requirements. The processed raw materials are then fed into the molding mechanism through a conveying device.

[0070] Step Two: The extrusion screw 202 begins to rotate. Under the rotational push and heating action of the screw, the plastic raw material in the molding mechanism is gradually plasticized to a molten state. The molten plastic is continuously extruded from the end of the molding mechanism in a tubular form under the extrusion action of the screw.

[0071] Step 3: The extruded plastic tube first passes through the guide cover 105, whose inner wall is rounded and chamfered to prevent the plastic tube from bending naturally, ensuring that the plastic tube enters the cooling cylinder 101 in a straight line, creating conditions for uniform cooling.

[0072] Step 4: The straight plate 303 drives the sliding plug 304 to move up and down, and the water is drawn from the cold water tank 306 through the water pumping pipe 306. The cold water is discharged from multiple drainage tanks 103 through the drain pipe 404 and the connecting pipe 404, which completely covers the plastic pipe wall for cooling. The drain water is then returned to the cold water tank for circulation.

[0073] Step 5: When the straight plate 303 moves up and down, it drives the inverted trapezoidal lifting plate 402 to rise and fall, stirring the cold water in the cold water pool 306, accelerating its flow, eliminating local temperature differences, ensuring uniform cooling of the plastic pipe as a whole, and improving the cooling effect and pipe quality.

Claims

1. A device for processing waste plastic into plastic pipes, characterized in that: It includes a cold water pool, a cooling cylinder fixedly connected to the upper end of the cold water pool, a cavity inside the cooling cylinder, a water inlet pipe fixedly connected to the side wall of the cooling cylinder, and multiple drainage grooves opened on the inner wall of the cooling cylinder. The water inlet pipe and multiple drainage grooves are all connected to the cavity, and a forming mechanism is connected to the upper end of the cold water pool.

2. The equipment for processing waste plastics into plastic pipes according to claim 1, characterized in that: A guide cover is fixedly connected to one end of the cooling cylinder.

3. The equipment for processing waste plastics into plastic pipes according to claim 2, characterized in that: The forming mechanism includes an extrusion cylinder, an extrusion screw is rotatably connected inside the extrusion cylinder, a feed port is opened at the upper end of the extrusion cylinder, a discharge pipe is fixedly connected to the front end of the extrusion cylinder, and a forming column is fixedly connected inside the discharge pipe.

4. The equipment for processing waste plastics into plastic pipes according to claim 3, characterized in that: A sliding cylinder is fixedly connected to the cold water tank. A sliding plug is slidably connected inside the sliding cylinder. A straight plate is fixedly connected to the upper end of the sliding plug. A water pumping pipe is fixedly connected to the lower end of the sliding cylinder. A drain pipe is fixedly connected to the sliding cylinder. A connecting pipe is fixedly connected between the drain pipe and the water inlet pipe. Valves are installed in both the water pumping pipe and the drain pipe.

5. The equipment for processing waste plastics into plastic pipes according to claim 4, characterized in that: A crankshaft is fixedly connected to the shaft of the extrusion screw, and a connecting rod is rotatably connected to the crankshaft. One end of the connecting rod is rotatably connected to a straight plate.

6. The equipment for processing waste plastics into plastic pipes according to claim 5, characterized in that: A drive motor is fixedly connected to the extrusion cylinder, and one end of the crankshaft is fixedly connected to the output shaft of the drive motor.

7. The equipment for processing waste plastics into plastic pipes according to claim 6, characterized in that: A connecting frame is fixedly connected to the straight plate, and two lifting plates are fixedly connected to the lower end of the connecting frame.

8. The equipment for processing waste plastics into plastic pipes according to claim 7, characterized in that: Both lifting platforms are V-shaped.

9. The equipment for processing waste plastics into plastic pipes according to claim 7, characterized in that: Both lifting platforms are inverted trapezoidal in shape.

10. A method for processing plastic pipes using the processing equipment of claim 9, characterized in that, The method includes the following steps: Step 1: First, the recycled waste plastic is crushed and cleaned to remove impurities and foreign objects. Then, it is mixed evenly with additives in a certain proportion to form plastic raw materials that meet the processing requirements. The processed raw materials are then fed into the molding mechanism through a conveying device. Step Two: The extrusion screw begins to rotate. Under the driving force and heating effect of the screw's rotation, the plastic raw material in the molding mechanism is gradually plasticized to a molten state. The molten plastic is continuously extruded from the end of the molding mechanism in a tubular form under the extrusion action of the screw. Step 3: The extruded plastic tube first passes through the guide cover, whose inner wall is rounded and chamfered to prevent the plastic tube from bending naturally, ensuring that the plastic tube enters the cooling cylinder in a straight line, creating conditions for uniform cooling. Step 4: Move the sliding plug up and down using the straight plate, draw water from the cold water tank using the water pumping pipe, and discharge the cold water from multiple drainage channels through the drain pipe and connecting pipe, completely covering the plastic pipe wall for cooling, and then drain the water back to the cold water tank for circulation. Step 5: When the straight plate moves up and down, it drives the inverted trapezoidal lifting plate to rise and fall, stirring the cold water in the cold water pool, accelerating its flow, eliminating local temperature differences, ensuring uniform cooling of the plastic pipe as a whole, and improving the cooling effect and pipe quality.

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