Single-stage double-helix PET foamed plate extrusion device

Abstract

This application relates to a single-stage double-helix PET foam sheet extrusion device, belonging to the technical field of plastic processing equipment. It includes two molds, each with a die lip connected to one end. Both molds are connected to a twin-screw extruder. Each die lip has a groove extending to an opposite side. A sliding plate slides within the groove and is connected to an adjusting plate. One end of the adjusting plate extends beyond the die lip, dividing the groove into a first oil chamber and a second oil chamber. The adjusting plate extends out of the first oil chamber from the die lip. A first hydraulic cylinder is connected to the die lip, and a stop plate extends into the second oil chamber and abuts against the adjusting plate. The ends of both molds furthest from the die lip are connected to the twin-screw extruder. The die lip has a first pressure port communicating with the first oil chamber and a second pressure port communicating with the second oil chamber. This application achieves precise control of sheet thickness and improves the surface smoothness of the sheet.

Description

Technical Field

[0001] This application relates to the field of plastic processing equipment technology, and in particular to a single-stage double-helix PET foam extrusion device. Background Technology

[0002] PET (polyethylene terephthalate) foamed sheets are a new type of material widely used in packaging, construction, and other fields. They possess excellent impact resistance, chemical corrosion resistance, and lightweight properties. Current PET foamed sheet production typically employs extrusion molding processes, with the core equipment being the extrusion unit and molds.

[0003] Traditional PET foam extrusion molds typically use bolts to adjust the die lip spacing to control the sheet thickness. This method is not only cumbersome to adjust, but also prone to micro-deformation of the die lip surface due to uneven force during adjustment, thus affecting the uniformity of sheet thickness. This deformation is particularly pronounced under high temperature and pressure conditions, resulting in uneven thickness and an uneven surface in the finished sheet.

[0004] Moreover, during the extrusion process of PET foamed sheets, the molten material exerts a large pressure on the die lip. Traditional extrusion equipment is difficult to adjust in real time according to the pressure changes of the material, which may lead to excessive pressure accumulation during extrusion, further aggravating the deformation of the die lip, and thus affecting the molding effect and thickness accuracy of the foamed sheets. Summary of the Invention

[0005] In order to achieve precise control of the sheet thickness and improve the surface flatness of the sheet, this application provides a single-stage double-helix PET foam sheet extrusion device.

[0006] The single-stage double-helix PET foam extrusion device provided in this application adopts the following technical solution: A single-stage double-helix PET foam extrusion device includes two molds, one end of which is connected to a die lip. The two molds are arranged opposite each other, and the two die lips are also arranged opposite each other. The two molds are connected to a twin-screw extruder. Each die lip has a groove extending through to one side of the opposite die lips. A sliding plate is slidably disposed within the groove, and an adjusting plate is connected to the sliding plate. One end of the adjusting plate extends out of the die lip, and the sliding plate divides the groove into a first oil chamber and a second oil chamber. The adjusting plate extends out of the first oil chamber from the die lip. The die lip is connected to a first hydraulic cylinder, which is connected to an abutment plate. The abutment plate can extend into the second oil chamber and abut against the adjusting plate. The ends of the two molds away from the die lips are connected to the twin-screw extruder. The die lips have a first pressure port communicating with the first oil chamber and a second pressure port communicating with the second oil chamber.

[0007] By adopting the above technical solution, a groove is set inside the die lip, and a sliding plate is used to divide the groove into a first oil chamber and a second oil chamber, thereby realizing hydraulic control of the position of the two adjusting plates. By injecting hydraulic oil into the first oil chamber and the second oil chamber respectively, the movement of the adjusting plates can be precisely controlled, thereby flexibly adjusting the spacing between the adjusting plates. The extruded material is extruded from between the two adjusting plates, ensuring the uniformity of the sheet thickness. The oil pressure in the first and second oil chambers can be dynamically adjusted according to the pressure changes of the molten material (for example, by releasing part of the oil pressure in the first oil chamber, the oil pressure in the first oil chamber, the pressure of the extruded material, and the oil pressure in the second oil chamber are in a dynamic equilibrium). During extrusion, the pressure of the material on the regulating plate can be monitored in real time through the pressure feedback system in the hydraulic system, ensuring that the pressure of the material is stable during extrusion, preventing excessive pressure accumulation that could lead to die lip deformation or sheet thickness fluctuations, thereby enabling precise control of sheet thickness and improving the surface flatness of the sheet.

[0008] Optionally, the ends of the two mold bodies furthest from the die lip are connected to a first connecting pipe, the first connecting pipe is connected to a melt pump, the melt pump is connected to a second connecting pipe, the second connecting pipe is connected to the twin-screw extruder, and a flow chamber is provided on the opposite side of the two mold bodies, the flow chamber is connected to the extrusion channel between the two mold bodies.

[0009] By adopting the above technical solution, the flow stability of the material is further improved by the melt pump after it exits the twin-screw extruder. The melt pump can compensate for pressure fluctuations or uneven flow that may occur during extrusion, thereby ensuring a more uniform and stable material flow at the regulating plate.

[0010] By adjusting the operating parameters of the melt pump, the flow rate and pressure of the material can be flexibly controlled to adapt to the extrusion requirements of sheets of different thicknesses and specifications. Meanwhile, the flow chamber design allows for smoother flow of molten material within the mold, preventing uneven material distribution at the die lip and regulating plate. It provides a more ample flow path, ensuring the material reaches ideal pressure and velocity distribution before extrusion. This effectively improves the forming quality of the sheet material and reduces defects such as surface ripples and uneven thickness caused by uneven material flow.

[0011] Optionally, a first pressure sensor is installed in the first oil chamber, a second pressure sensor is installed in the second oil chamber, a displacement sensor is installed on the side of the second oil chamber facing the sliding plate, and a detection hole is provided on the abutment plate. The displacement sensor detects the distance between the adjustment plate and the top wall of the second oil chamber through the detection hole.

[0012] By adopting the above technical solution, and through the cooperation of the first pressure sensor, the second pressure sensor, and the displacement sensor, the system can monitor and adjust the pressure in the first oil chamber and the position of the sliding plate in the second oil chamber in real time, ensuring precise control of the sliding plate position during the extrusion process.

[0013] Based on feedback from the first pressure sensor, the second pressure sensor, and the displacement sensor, the system adjusts the flow and pressure of the hydraulic oil in a timely manner to prevent the regulating plate from shifting due to uneven pressure or external factors during the material extrusion process.

[0014] Optionally, a heating channel is provided in the mold body, and the heating channels of the two mold bodies are arranged together to form a spiral channel. The heating channel and the extrusion channel between the two mold bodies are independently set. One mold body is provided with an oil injection port and the other mold body is provided with an oil outlet. Both the oil outlet and the oil injection port are connected to the heating channel on the corresponding mold body.

[0015] By adopting the above technical solution, hot oil is injected into the heating channel, thereby providing a continuous heat source for the mold body. This prevents the material from cooling down due to long transmission distances or changes in ambient temperature during transmission, ensuring good material flowability.

[0016] Optionally, a first annular cooling channel is provided inside the mold lip, the first annular cooling channel is arranged around the slide groove, the first annular cooling channel and the slide groove are arranged independently of each other, and an inlet and an outlet communicating with the first annular cooling channel are provided on the mold lip.

[0017] By adopting the above technical solution, the temperature of the hydraulic oil can be effectively controlled, avoiding pressure fluctuations caused by the thermal expansion of the hydraulic oil. This maintains stable feedback from the first and second pressure sensors, preventing the adjustment plate from shifting due to pressure instability during extrusion. This ensures the uniformity of the sheet thickness and the smoothness of the surface.

[0018] Optionally, a support plate is provided in the first oil cavity on the side facing the sliding plate, the support plate is arranged along the length direction of the adjusting plate, and a sealing strip is provided on the top surface of the support plate.

[0019] By adopting the above technical solution, the support plate supports the sliding plate, ensuring that the first pressurization port is always located below the sliding plate, thus preventing the first oil chamber from being completely closed.

[0020] Optionally, a primary cooling assembly is provided on the side of the adjusting plate away from the mold body, a secondary cooling assembly is provided on the side of the die lip away from the mold body, and a tertiary cooling assembly is provided on the side of the secondary cooling assembly away from the die lip. The primary cooling assembly is used to cool the extruded material to a preliminary surface solidification state, the secondary cooling assembly is used to cool the extruded material to a preliminary internal solidification state, and the tertiary cooling assembly is used to cool the extruded material to the final rigid stage.

[0021] By employing the above technical solution, the primary cooling component quickly brings the surface of the extruded material to a preliminary solidification state, preventing deformation or surface defects during subsequent processing. The secondary cooling component further reduces the material temperature, causing the interior to gradually solidify and achieve a stable internal structure. Finally, the tertiary cooling component cools the material to its final rigid stage. This multi-stage cooling system ensures a more precise cooling process and avoids stress concentration or internal stress caused by rapid cooling. This not only improves the surface quality of the product but also ensures a uniform and stable internal structure. This gradual cooling method effectively reduces the occurrence of cracks and deformation, thereby ensuring that the physical properties of the entire sheet material meet the desired requirements.

[0022] Optionally, the primary cooling assembly includes a cooling roller. A bracket is installed at one end of the adjusting plate extending from the mold lip. A support shaft is rotatably connected to the bracket. The cooling roller is sleeved and fixed on the support shaft. A liquid injection channel is opened inside the support shaft. A second annular cooling channel is opened in the cooling roller. The liquid injection channel communicates with the second annular cooling channel. A connector is connected to the end of the bracket. A liquid injection pipe is connected to the connector. The connector is rotatably connected to the support shaft. The end face of the connector is in contact with the end face of the cooling roller. The circumferential surface of the cooling roller and the circumferential surface of the connector are both tangent to the extended surface of the end face of the adjusting plate.

[0023] By adopting the above technical solution, the circumferential surfaces of the cooling roller and the connector are tangent to the end face of the adjusting plate. This means that when the material is extruded from the die lip, it directly contacts the circumferential surfaces of the cooling roller and the connector. The cooling roller can quickly remove heat from the surface of the extruded material, causing the material surface to cool rapidly and initially solidify, thereby preventing the surface of the high-temperature extruded material from flowing or deforming in the air. This design can improve the surface quality of the extruded material and reduce the generation of surface defects. Especially during high-speed extrusion, this cooling method can maintain the stability of the material surface. At the same time, the cooling roller can ensure uniform cooling, avoiding surface stress or wrinkles caused by uneven cooling.

[0024] Optionally, the secondary cooling assembly includes a conveyor table with two lifting plates mounted on it, the two lifting plates being arranged opposite each other. A second hydraulic cylinder is provided on the conveyor table for controlling the relative movement of the two lifting plates. A cooling water tank is provided inside each lifting plate, and an injection port and a drainage port communicating with the cooling water tank are provided on each lifting plate. An active roller is installed at the end of one lifting plate away from the mold lip, and a passive roller is installed at the end of the other lifting plate away from the mold lip. A motor is installed on one lifting plate, and the motor is connected to the active roller.

[0025] By adopting the above technical solution, the lifting plate can be in contact with the surface of the extruded material for cooling, allowing the cooling water in the cooling water tank to effectively remove heat from the material, thereby cooling the interior of the material and ensuring that the interior of the material can reach a preliminary solidification state. This process ensures the overall uniformity of material cooling.

[0026] The second hydraulic cylinder controls the distance between the two lifting plates to be the same as the distance between the adjusting plates, ensuring that the lifting plates can be flexibly adjusted according to the material thickness during the cooling process. Furthermore, the drive roller, driven by a motor, not only maintains a uniform speed of material movement during cooling but also, in conjunction with the melt pump adjustment, controls the material's movement speed to adjust the cooling time. This design allows the cooling process to maintain consistency with the overall rhythm of the production line.

[0027] Optionally, the three-stage cooling assembly includes a bottom support and a top mounting base. The bottom support has several air inlets, and several exhaust pipes are installed inside the bottom support and on the top mounting base. Each exhaust pipe has several exhaust outlets.

[0028] By adopting the above technical solution, the multi-exhaust pipe design achieves functions such as multi-point exhaust, bidirectional cooling from top to bottom, and forced convection, further improving the efficiency and uniformity of the material cooling process. It effectively prevents heat accumulation or uneven cooling during the cooling process, ensuring that the material achieves the ideal cooling effect in the final rigid stage.

[0029] In summary, this application includes at least one of the following beneficial technical effects: 1. A groove is set inside the die lip, and a sliding plate is used to divide the groove into a first oil chamber and a second oil chamber, realizing hydraulic control of the position of the two adjusting plates. By injecting hydraulic oil into the first oil chamber and the second oil chamber respectively, the movement of the adjusting plates can be precisely controlled, thereby flexibly adjusting the spacing between the adjusting plates. The extruded material is extruded from between the two adjusting plates, ensuring the uniformity of the sheet thickness; 2. The oil pressure in the first and second oil chambers can be dynamically adjusted according to the pressure changes of the molten material (for example, by releasing part of the oil pressure in the first oil chamber, the oil pressure in the first oil chamber, the pressure of the extruded material, and the oil pressure in the second oil chamber can be dynamically balanced). During the extrusion process, the pressure of the material on the regulating plate can be monitored in real time through the pressure feedback system in the hydraulic system to ensure that the pressure of the material is stable during extrusion, prevent excessive pressure accumulation from causing die lip deformation or sheet thickness fluctuation, and thus achieve precise control of sheet thickness and improve the surface flatness of the sheet. 3. The design of the first annular cooling channel effectively controls the temperature of the hydraulic oil, avoiding pressure fluctuations caused by thermal expansion of the hydraulic oil. This maintains stable feedback from the first and second pressure sensors, preventing the adjustment plate from shifting due to pressure instability during extrusion. This ensures uniformity of sheet thickness and surface finish. 4. The primary cooling assembly first rapidly brings the surface of the extruded material to a preliminary solidification state, preventing deformation or surface defects during subsequent processing. The secondary cooling assembly further reduces the material temperature, allowing the interior to gradually solidify and achieve a stable internal structure. Finally, the tertiary cooling assembly cools the material to its final rigid stage. This multi-stage cooling system ensures a more precise cooling process and avoids stress concentration or internal stress caused by rapid cooling. This not only improves the surface quality of the product but also ensures a uniform and stable internal structure. This gradual cooling method effectively reduces the occurrence of cracks and deformation, thereby ensuring that the physical properties of the entire sheet material meet the desired requirements. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0031] Figure 2 This is a schematic diagram illustrating the structure of the heating channel and the flow chamber in an embodiment of this application.

[0032] Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the middle.

[0033] Figure 4 This is a schematic diagram illustrating the structure of the liquid inlet, liquid outlet, oil filling port, and oil outlet in the embodiments of this application.

[0034] Figure 5 This is a schematic diagram illustrating the structure of the primary cooling component in an embodiment of this application.

[0035] Figure 6 This is a schematic diagram illustrating the structure of the liquid injection channel and the second annular cooling channel in an embodiment of this application.

[0036] Figure 7This is a schematic diagram illustrating the structure of the motor, the injection port, and the drain port in an embodiment of this application.

[0037] Figure 8 This is a schematic diagram illustrating the structure of the air intake and exhaust pipe in the embodiments of this application.

[0038] Explanation of reference numerals in the attached drawings: 1. Twin-screw extruder; 11. First connecting pipe; 12. Second connecting pipe; 2. Die body; 21. Flow groove; 22. Flow chamber; 23. Heating channel; 24. Oil inlet; 25. Oil outlet; 3. Die lip; 31. Slide groove; 311. First oil chamber; 312. Second oil chamber; 32. Sliding plate; 33. Adjusting plate; 34. First hydraulic cylinder; 35. Abutment plate; 351. Detection hole; 36. First pressure port; 37. Second pressure port; 38. Support plate; 39. Sealing strip; 310. First annular cooling channel; 313. Liquid inlet; 314. Liquid outlet; 41. First pressure sensor; 4 2. Second pressure sensor; 43. Displacement sensor; 5. Primary cooling assembly; 51. Cooling roller; 511. Second annular cooling channel; 52. Bracket; 53. Support shaft; 531. Liquid injection channel; 54. Connector; 55. Liquid injection pipe; 6. Secondary cooling assembly; 61. Conveyor table; 62. Lifting plate; 621. Cooling water tank; 622. Liquid injection port; 623. Liquid discharge port; 63. Second hydraulic cylinder; 64. Active roller; 65. Passive roller; 66. Motor; 7. Tertiary cooling assembly; 71. Bottom support seat; 711. Air inlet; 72. Top mounting seat; 73. Exhaust pipe; 731. Exhaust port; 8. Melt pump. Detailed Implementation

[0039] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0040] This application discloses a single-stage double-helix PET foam extrusion device.

[0041] like Figure 1 and Figure 2 The single-stage twin-screw PET foam extrusion device includes a twin-screw extruder 1. The output end of the twin-screw extruder 1 is connected to a second connecting pipe 12, which is connected to a melt pump 8. The melt pump 8 is connected to a first connecting pipe 11, which connects to two molds 2. Each mold 2 has a flow groove 21 on its opposite side, forming an extrusion channel. Furthermore, each mold 2 has two flow chambers 22 on its opposite side, each flow chamber 22 being a semi-cylindrical groove. A die lip 3 is installed at the end of the mold 2 furthest from the first connecting pipe 11, and the two die lips 3 are positioned opposite each other.

[0042] like Figure 3 and Figure 4Heating channels 23 are provided inside the mold body 2. The heating channels 23 of the two mold bodies 2 are arranged together to form a spiral channel. The heating channels 23 and the extrusion channels between the two mold bodies 2 are set independently. An oil injection port 24 is provided on one mold body 2 and an oil outlet 25 is provided on the other mold body 2. Both the oil outlet 25 and the oil injection port 24 are connected to the heating channels 23 on the corresponding mold body 2.

[0043] Both mold lips 3 have grooves 31 extending to opposite sides. A sliding plate 32 slides within each groove 31, connected to an adjusting plate 33. One end of the adjusting plate 33 extends out of the mold lip 3. The sliding plate 32 divides the groove 31 into a first oil cavity 311 and a second oil cavity 312. The first oil cavity 311 extends to opposite sides of the two mold lips 3. A first hydraulic cylinder 34 is located at the top of each mold lip 3. The piston rod of the first hydraulic cylinder 34 penetrates into the mold lip 3 and is connected to an abutment plate 35. The abutment plate 35 has a U-shaped longitudinal section and can extend into the second oil cavity 312, abutting against the sliding plate 32. The mold lip 3 has a first pressure port 36 communicating with the first oil cavity 311 and a second pressure port 37 communicating with the second oil cavity 312. A support plate 38 is provided in the first oil cavity 311 on the side facing the sliding plate 32. The support plate 38 is arranged along the length of the adjusting plate 33. A sealing strip 39 is provided on the top surface of the support plate 38. The sealing strip 39 is also pressed against the circumference of the adjusting plate 33.

[0044] like Figure 3 , Figure 4 and Figure 5 The mold lip 3 has a first annular cooling channel 310 inside, which surrounds the slide groove 31. The first annular cooling channel 310 is independently set with the slide groove 31, the first pressurizing port 36 and the second pressurizing port 37. The mold lip 3 has a liquid inlet 313 and a liquid outlet 314 that communicate with the first annular cooling channel 310.

[0045] A first pressure sensor 41 is installed on the inner wall of the first oil chamber 311, and a second pressure sensor 42 is installed on the inner wall of the second oil chamber 312. A displacement sensor 43 is installed on the side of the second oil chamber 312 facing the sliding plate 32. A detection hole 351 is provided on the abutment plate 35. The displacement sensor 43 detects the distance between the adjusting plate 33 and the inner top wall of the second oil chamber 312 through the detection hole 351. The mold lip 3 is composed of detachable modular components.

[0046] like Figure 1 and Figure 4A primary cooling assembly 5 is installed on the side of the adjusting plate 33 facing away from the mold body 2. A secondary cooling assembly 6 is installed on the side of the die lip 3 facing away from the mold body 2. A tertiary cooling assembly 7 is installed on the side of the secondary cooling assembly 6 facing away from the die lip 3. The primary cooling assembly 5 is used to cool the extruded material to a preliminary surface solidification state, the secondary cooling assembly 6 is used to cool the extruded material to a preliminary internal solidification state, and the tertiary cooling assembly 7 is used to cool the extruded material to the final rigid stage. In actual operation, the primary cooling assembly 5 cools the PET sheet from 250℃ to about 150℃, the secondary cooling assembly 6 cools the PET sheet from 150℃ to about 80℃, and the tertiary cooling assembly 7 cools the PET sheet from 80℃ to room temperature.

[0047] When adjusting the two adjusting plates 33, hydraulic oil is first injected into the first oil chamber 311. The displacement sensor 43 detects the distance between the adjusting plate 33 and the inner top wall of the second oil chamber 312. After the adjusting plate 33 reaches the set position, hydraulic oil is injected into the second oil chamber 312. When the value of the second pressure sensor 42 is the same as the value of the first pressure sensor 41, pressure is continued to be applied to the first oil chamber 311 and the second oil chamber 312 to make the first oil chamber 311 and the second oil chamber 312 have higher oil pressure, thereby keeping the adjusting plate 33 in a fixed state.

[0048] Then, the twin-screw extruder 1 and melt pump 8 are started, hot oil is injected into the heating channel 23, and coolant is injected into the first annular cooling channel 310. When the material is extruded between the two regulating plates 33, the oil pressure in the first oil chamber 311 and the second oil chamber 312 can be dynamically adjusted according to the pressure change of the molten material. For example, by releasing part of the oil pressure in the first oil chamber 311, the oil pressure in the first oil chamber 311, the pressure of the extruded material, and the oil pressure in the second oil chamber 312 are in a dynamic balance. The material rate is adjusted by regulating the melt pump 8, thereby changing the pressure of the material on the regulating plate 33. Then, the material passes through the primary cooling assembly 5, the secondary cooling assembly 6, and the tertiary cooling assembly 7 in sequence, and after forming, it enters the cutting device for cutting.

[0049] A sliding plate 32 divides the chute 31 into a first oil chamber 311 and a second oil chamber 312, enabling hydraulic control of the positions of the two adjusting plates 33. By injecting hydraulic oil into the first oil chamber 311 and the second oil chamber 312 respectively, the movement of the adjusting plates 33 can be precisely controlled, thereby flexibly adjusting the spacing between the adjusting plates 33. The extruded material is extruded between the two adjusting plates 33, ensuring the uniformity of the plate thickness. During the extrusion process, the pressure of the material on the regulating plate 33 can be monitored in real time through the pressure feedback system in the hydraulic system to ensure that the pressure of the material is stable during extrusion, prevent excessive pressure accumulation from causing deformation of the die lip 3 or fluctuation in the thickness of the sheet, thereby achieving precise control of the sheet thickness and improving the surface flatness of the sheet.

[0050] Hot oil is injected into the heating channel 23, thereby providing a continuous heat source for the mold body 2, so that the material is not prone to temperature drop due to long transmission distance or changes in ambient temperature during transmission, and the material has good flowability.

[0051] The first annular cooling channel 310 effectively controls the temperature of the hydraulic oil, avoiding pressure fluctuations caused by the thermal expansion of the hydraulic oil, thereby maintaining stable feedback from the first pressure sensor 41 and the second pressure sensor 42, and preventing the position of the adjusting plate 33 from shifting due to pressure instability during the extrusion process. This ensures the uniformity of the sheet thickness and the surface finish.

[0052] The primary cooling assembly 5 first rapidly brings the surface of the extruded material to a preliminary solidification state, preventing deformation or surface defects during subsequent processing. The secondary cooling assembly 6 further reduces the material temperature, allowing the interior to gradually solidify and achieve a stable internal structure. Finally, the tertiary cooling assembly 7 cools the material to its final rigid stage. This multi-stage cooling system ensures more precise cooling and avoids stress concentration or internal stress caused by rapid cooling. This not only improves the surface quality of the product but also ensures a uniform and stable internal structure. This gradual cooling method effectively reduces the occurrence of cracks and deformation, thereby ensuring that the physical properties of the entire sheet material meet the desired requirements.

[0053] like Figure 5 and Figure 6 The primary cooling assembly 5 includes a cooling roller 51. A bracket 52 is installed at one end of the adjusting plate 33 that extends out of the mold lip 3. The bracket 52 is rotatably connected to a support shaft 53. The cooling roller 51 is sleeved and fixed on the support shaft 53. The circumferential surface of the cooling roller 51 is tangent to the extended end face of the adjusting plate 33. A liquid injection channel 531 is opened in the support shaft 53. A second annular cooling channel 511 is opened in the cooling roller 51. The liquid injection channel 531 is connected to the second annular cooling channel 511. A connector 54 is connected to the end of the bracket 52. A liquid injection pipe 55 is connected to the connector 54. The liquid injection pipe 55 extends from the side away from the mold body 2. The connector 54 is connected to the support shaft 53. The circumferential surface of the cooling roller 51 and the circumferential surface of the connector 54 are both tangent to the extended end face of the adjusting plate 33.

[0054] like Figure 2 and Figure 7The secondary cooling assembly 6 includes a conveyor platform 61, on which two lifting plates 62 are mounted, positioned opposite each other. A second hydraulic cylinder 63 is mounted on the conveyor platform 61 to control the relative movement of the two lifting plates 62; one second hydraulic cylinder 63 is mounted on the top of the conveyor platform 61, and the other is mounted on the bottom. A cooling water tank 621 is formed within each lifting plate 62, and each lifting plate 62 has an injection port 622 and an outlet 623 communicating with the cooling water tank 621. A drive roller 64 is mounted on the end of one lifting plate 62 furthest from the mold lip 3, and a passive roller 65 is mounted on the end of the other lifting plate 62 furthest from the mold lip 3. A motor 66 is mounted on one lifting plate 62 and connected to the drive roller 64. like Figure 8 The three-stage cooling assembly 7 includes a bottom support 71 and a top mounting base 72. The bottom support 71 has several air inlets 711. Several exhaust pipes 73 are installed inside the bottom support 71 and on the top mounting base 72. Each exhaust pipe 73 has several exhaust outlets 731. The exhaust pipes 73 are arranged along the width direction of the mold lip 3 and are equidistant along the length direction of the bottom support 71.

[0055] The circumferential surface of the cooling roller 51 is tangent to the end face of the adjusting plate 33, meaning that when the material is extruded from the die lip 3, it directly contacts the circumferential surface of the cooling roller 51. The cooling roller 51 can quickly remove heat from the surface of the extruded material, causing the material surface to cool rapidly and initially solidify, thus preventing the surface of the high-temperature extruded material from flowing or deforming in the air. This design can improve the surface quality of the extruded material and reduce the generation of surface defects, especially during high-speed extrusion, where this cooling method can maintain the stability of the material surface. At the same time, the cooling roller 51 ensures uniform cooling, avoiding surface stress or wrinkles caused by uneven cooling.

[0056] The lifting plate 62 can be in contact with the surface of the extruded material to cool it, allowing the cooling water in the cooling water tank 621 to effectively remove heat from the material, thereby cooling the interior of the material and ensuring that the interior of the material can reach a preliminary solidification state. This process ensures the overall uniformity of cooling of the material.

[0057] The second hydraulic cylinder 63 can control the distance between the two lifting plates 62 to be the same as the distance between the adjusting plate 33, ensuring that the lifting plates 62 can be flexibly adjusted according to the different thicknesses of the material during the cooling process. Furthermore, the drive roller 64, driven by the motor 66, not only ensures that the material moves at a uniform speed during the cooling process, but also, in conjunction with the adjustment of the melt pump 8, controls the material's movement speed to adjust the cooling time. This design allows the cooling process to be synchronized with the overall rhythm of the production line.

[0058] The multi-exhaust pipe 73 design enables multi-point exhaust, bidirectional cooling from top and bottom, and forced convection, further improving the efficiency and uniformity of the material cooling process. It effectively prevents heat buildup or uneven cooling during the process, ensuring the material achieves ideal cooling performance in its final rigid stage.

[0059] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A single-stage double-helix PET foam extrusion device, characterized in that: The device includes two mold bodies (2), one end of which is connected to a die lip (3). The two mold bodies (2) are arranged opposite each other, and the two die lips (3) are arranged opposite each other. The ends of the two mold bodies (2) away from the die lips (3) are connected to a twin-screw extruder (1). Each die lip (3) has a groove (31) inside it, which extends to the opposite side of the two die lips (3). A sliding plate (32) is slidably arranged in the groove (31), and an adjusting plate (33) is connected to the sliding plate (32). The sliding plate (32) divides the groove (31) into a first oil cavity (311) and a second oil cavity (312). One end of the adjusting plate (33) extends out of the die lip (311) through the first oil cavity (311). The mold lip (3) is connected to a first hydraulic cylinder (34), the first hydraulic cylinder (34) is connected to an abutment plate (35), the abutment plate (35) can extend into the second oil cavity (312) and abut against the adjusting plate (33), the mold lip (3) is provided with a first pressure port (36) communicating with the first oil cavity (311) and a second pressure port (37) communicating with the second oil cavity (312), a support plate (38) is provided in the first oil cavity (311) facing the sliding plate (32), the support plate (38) is provided along the length direction of the adjusting plate (33), the top surface of the support plate (38) is provided with a sealing strip (39), and the sealing strip (39) abuts against the circumferential surface of the adjusting plate (33); A first pressure sensor (41) is installed in the first oil chamber (311), a second pressure sensor (42) is installed in the second oil chamber (312), a displacement sensor (43) is installed on the side of the second oil chamber (312) facing the sliding plate (32), and a detection hole (351) is provided on the abutment plate (35). The displacement sensor (43) detects the distance between the adjusting plate (33) and the top wall of the second oil chamber (312) through the detection hole (351).

2. The single-stage double-helix PET foam extrusion device according to claim 1, characterized in that: The two mold bodies (2) are connected to a first connecting pipe (11) at the ends away from the die lip (3). The first connecting pipe (11) is connected to a melt pump (8). The melt pump (8) is connected to a second connecting pipe (12). The second connecting pipe (12) is connected to the twin-screw extruder (1). A flow chamber (22) is provided on the opposite side of the two mold bodies (2). The flow chamber (22) is connected to the extrusion channel between the two mold bodies (2).

3. The single-stage double-helix PET foam extrusion device according to claim 1, characterized in that: Heating channels (23) are provided inside the mold body (2). The heating channels (23) of the two mold bodies (2) are arranged together to form a spiral channel. The heating channels (23) and the extrusion channels between the two mold bodies (2) are set independently. An oil injection port (24) is provided on one mold body (2) and an oil outlet (25) is provided on the other mold body (2). The oil outlet (25) and the oil injection port (24) are both connected to the heating channels (23) on the corresponding mold body (2).

4. The single-stage double-helix PET foam extrusion device according to claim 1, characterized in that: The mold lip (3) is provided with a first annular cooling channel (310), which surrounds the slide groove (31). The first annular cooling channel (310) and the slide groove (31) are independently provided. The mold lip (3) is provided with an inlet (313) and an outlet (314) that communicate with the first annular cooling channel (310).

5. The single-stage double-helix PET foam extrusion device according to claim 1, characterized in that: The adjusting plate (33) is provided with a primary cooling component (5) on the side away from the mold body (2), the mold lip (3) is provided with a secondary cooling component (6) on the side away from the mold body (2), and the secondary cooling component (6) is provided with a tertiary cooling component (7) on the side away from the mold lip (3). The primary cooling component (5) is used to cool the extruded material to a preliminary solidification state on the surface, the secondary cooling component (6) is used to cool the extruded material to a preliminary solidification state inside, and the tertiary cooling component (7) is used to cool the extruded material to the final rigid stage.

6. The single-stage double-helix PET foam extrusion device according to claim 5, characterized in that: The primary cooling assembly (5) includes a cooling roller (51). A bracket (52) is installed on one end of the adjusting plate (33) extending out of the mold lip (3). The bracket (52) is rotatably connected to a support shaft (53). The cooling roller (51) is sleeved and fixed on the support shaft (53). An injection channel (531) is opened in the support shaft (53). The cooling roller (51) has a second annular cooling channel (511). The injection channel (531) communicates with the second annular cooling channel (511). A connector (54) is connected to the end of the bracket (52). An injection pipe (55) is connected to the connector (54). The connector (54) communicates with the support shaft (53). The end face of the connector (54) is in contact with the end face of the cooling roller (51). The circumferential surface of the cooling roller (51) and the circumferential surface of the connector (54) are both tangent to the extended end face of the adjusting plate (33).

7. The single-stage double-helix PET foam extrusion device according to claim 5, characterized in that: The secondary cooling assembly (6) includes a conveyor platform (61), on which two lifting plates (62) are installed. The two lifting plates (62) are arranged opposite to each other. A second hydraulic cylinder (63) is provided on the conveyor platform (61) for controlling the relative movement of the two lifting plates (62). A cooling water tank (621) is provided in the lifting plate (62). The lifting plate (62) has an injection port (622) and a drain port (623) communicating with the cooling water tank (621). An active roller (64) is installed at the end of one lifting plate (62) away from the mold lip (3), and a passive roller (65) is installed at the end of the other lifting plate (62) away from the mold lip (3). A motor (66) is installed on one lifting plate (62), and the motor (66) is connected to the active roller (64).

8. The single-stage double-helix PET foam extrusion device according to claim 5, characterized in that: The three-stage cooling assembly (7) includes a bottom support (71) and a top mounting base (72). The bottom support (71) has several air inlets (711). Several exhaust pipes (73) are installed in the bottom support (71) and on the top mounting base (72). Each exhaust pipe (73) has several exhaust ports (731).

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