Single-order double-helix PET foamed sheet extrusion device

Abstract

The invention relates to a single-order double-helix PET foamed sheet extrusion device, and belongs to the technical field of plastic processing equipment, the single-order double-helix PET foamed sheet extrusion device comprises two die bodies, one ends of the die bodies are connected with die lips, the two die bodies are jointly connected with a double-screw extruder, sliding grooves are formed in the two die lips, the sliding grooves penetrate to the opposite sides of the two die lips, and the two die lips are connected with the double-screw extruder. A sliding plate is arranged in the sliding groove in a sliding mode and connected with an adjusting plate, one end of the adjusting plate extends out of the die lip, the sliding plate divides the sliding groove into a first oil cavity and a second oil cavity, the adjusting plate extends out of the die lip from the first oil cavity, the die lip is connected with a first hydraulic cylinder, the first hydraulic cylinder is connected with an abutting plate, and the abutting plate can extend into the second oil cavity and abut against the adjusting plate. The ends, away from the die lip, of the two die bodies are jointly connected with a double-screw extruder, and a first pressurizing opening communicated with the first oil cavity and a second pressurizing opening communicated with the second oil cavity are formed in the die lip. The device has the effects of accurately controlling the thickness of the plate and improving the surface smoothness of the plate.

Description

Technical Field

[0001] The present application relates to the technical field of plastic processing equipment, and in particular to a single-stage double-screw PET foaming board extrusion device. Background Art

[0002] PET (polyethylene terephthalate) foam sheet is a new material widely used in packaging, construction and other fields. It has good impact resistance, chemical corrosion resistance and light weight. Existing PET foam sheet production usually adopts extrusion molding process, and the core equipment is extrusion device and mold.

[0003] Traditional PET foam sheet extrusion dies usually use bolts to adjust the die lip spacing to control the sheet thickness. This method is not only cumbersome to adjust, but also due to the uneven force on the die lip during adjustment, it is easy to cause slight deformation of the die lip surface, thus affecting the uniformity of the sheet thickness. Especially under high temperature and pressure environment, the deformation problem of the die lip is more prominent, resulting in uneven thickness and uneven surface of the finished sheet.

[0004] Moreover, during the extrusion process of PET foam boards, the molten material will exert 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 cause excessive pressure accumulation during extrusion, further aggravating the deformation of the die lip, and thus affecting the molding effect and thickness accuracy of the foam board. Summary of the invention

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

[0006] The single-stage double-screw PET foam sheet extrusion device provided in this application adopts the following technical solution: A single-stage double-screw PET foam board extrusion device comprises two die bodies, one end of each die body is connected with a die lip, the two die bodies are arranged opposite to each other, the two die lips are arranged opposite to each other, the two die bodies are commonly connected with a twin-screw extruder, a slide groove is provided in each of the two die lips, the slide groove passes through to the opposite side of the two die lips, a sliding plate is slidably provided in the slide groove, the sliding plate is connected with an adjustment plate, one end of the adjustment plate extends out of the die lip, the sliding plate divides the slide groove into a first oil chamber and a second oil chamber, the adjustment plate extends out of the first oil chamber and extends out of the die lip, the die lip is connected with a first hydraulic cylinder, the first hydraulic cylinder is connected with an abutment plate, the abutment plate can extend into the second oil chamber and abut against the adjustment plate, the two die bodies are commonly connected with a twin-screw extruder at one end away from the die lips, and a first pressurizing port connected to the first oil chamber and a second pressurizing port connected to the second oil chamber are provided on the die lip.

[0007] By adopting the above technical solution, a slide groove is set inside the die lip, and a sliding plate is used to separate the slide groove into a first oil chamber and a second oil chamber, so as to realize hydraulic control of the positions of the two adjustment plates. By injecting hydraulic oil into the first oil chamber and the second oil chamber respectively, the movement of the adjustment plates can be accurately controlled, so as to flexibly adjust the distance between the adjustment plates, and the extruded material is extruded from between the two adjustment plates to ensure the uniformity of the plate thickness; The oil pressure in the first oil chamber and the second oil chamber can be dynamically adjusted according to the pressure change of the molten material (for example, by removing 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 state.) During the extrusion process, the pressure of the material on the regulating plate can be monitored in real time by the pressure feedback system in the hydraulic system to ensure the stability of the pressure of the material during extrusion and prevent excessive pressure accumulation from causing deformation of the die lip or fluctuation in the thickness of the sheet, thereby achieving precise control of the sheet thickness and improving the surface smoothness of the sheet.

[0008] Optionally, one end of the two mold bodies away from the die lip is commonly 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 flow chambers are opened on opposite sides of the two mold bodies, and the flow chambers are connected to the extrusion channel between the two mold bodies.

[0009] By adopting the above technical solution, it is ensured that after the material comes out of the twin-screw extruder, the melt pump further improves the flow stability. The melt pump can compensate for the pressure fluctuation or uneven flow that may occur during the extrusion process, thereby ensuring that the material flow at the adjustment plate is more uniform and stable.

[0010] The flow rate and pressure of the material can be flexibly controlled by adjusting the operating parameters of the melt pump to meet the extrusion requirements of sheets of different thicknesses and specifications; At the same time, the design of the flow chamber can make the molten material flow more smoothly in the die body, while avoiding the uneven distribution of the material at the die lip and the adjustment plate. It provides a more sufficient flow path for the material, so that the material can reach the ideal pressure and flow rate distribution state before being extruded through the adjustment plate. This effectively improves the molding quality of the sheet and reduces defects such as surface ripples and uneven thickness of the sheet 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, a detection hole is opened on the abutment plate, and 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, 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 second oil chamber and the position of the sliding plate in real time, ensuring precise control of the sliding plate position during the extrusion process.

[0013] Based on the feedback from the first pressure sensor, the second pressure sensor and the displacement sensor, the system timely adjusts the flow and pressure of the hydraulic oil to prevent the adjustment plate from being offset 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 together surrounded to form a spiral channel. The heating channel and the extrusion channel between the two mold bodies are independently arranged from each other. An oil filling port is provided on one mold body, and an oil outlet is provided on the other mold body. The oil outlet and the oil filling port are both 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, making it difficult for the material to drop in temperature during the transmission process due to the long transmission distance or the temperature change of the surrounding environment, thereby ensuring good material fluidity.

[0016] Optionally, a first annular cooling channel is provided in the die 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 a liquid inlet and a liquid outlet connected to the first annular cooling channel are provided on the die lip.

[0017] By adopting the above technical solution, the temperature of the hydraulic oil can be effectively controlled to avoid pressure fluctuations caused by thermal expansion of the hydraulic oil, thereby maintaining stable feedback of the first pressure sensor and the second pressure sensor, and avoiding the position deviation of the adjustment plate caused by unstable pressure during the extrusion process. This ensures the uniformity of the thickness and surface finish of the sheet.

[0018] Optionally, a support plate is provided on a side of the first oil chamber facing the sliding plate, the support plate is provided along the length direction of the adjustment 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, so that the first pressurizing port is always located below the sliding plate, thereby preventing the first oil chamber from being in a completely closed state.

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

[0021] By adopting the above technical solution, the first-stage cooling component first allows the surface of the extruded material to quickly reach a preliminary solidification state to prevent the material from deforming or having surface defects during subsequent processing; the second-stage cooling component further reduces the material temperature, allowing the interior of the material to gradually solidify and achieve an internally stable structure; finally, the third-stage cooling component cools the material to the final rigid stage. The hierarchical control of multi-stage cooling 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 that its internal structure is uniform and stable. This gradual cooling method can effectively reduce the occurrence of cracks, deformation and other problems in the product, thereby ensuring that the physical properties of the entire sheet meet the ideal requirements.

[0022] Optionally, the primary cooling assembly includes a cooling roller, and a bracket is installed at one end of the adjustment plate extending out of the die lip, the bracket is rotatably connected to a support shaft, the cooling roller is sleeved and fixed on the support shaft, the support shaft is provided with an injection channel, the cooling roller is provided with a second annular cooling channel, the injection channel is connected to the second annular cooling channel, the end of the bracket is connected to a connector, the connector is connected to an injection pipe, the connector is rotatably connected to the support roller, the end face of the connector is butted against the end face of the cooling roller, the circumferential surface of the cooling roller and the circumferential surface of the connector are tangent to the extended surface of the end face of the adjustment plate.

[0023] By adopting the above technical solution, the circumference of the cooling roller and the circumference of the connector are tangent to the end face of the adjustment plate, which means that when the material is extruded from the die lip, it directly contacts the circumference of the cooling roller and the connector. The cooling roller can quickly take away the heat from the surface of the extruded material, so that the surface of the material is quickly cooled and initially solidified, 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 occurrence 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 and avoid surface stress or wrinkles caused by uneven cooling.

[0024] Optionally, the secondary cooling device includes a conveying platform, on which two lifting plates are installed, the two lifting plates are arranged opposite to each other, and a second hydraulic cylinder for controlling the relative movement of the two lifting plates is arranged on the conveying platform, a cooling water trough is provided in the lifting plates, and the lifting plates are provided with an injection port and a discharge port connected to the cooling water trough, an active roller is installed at one end of one of the lifting plates away from the die lip, a passive roller is installed at one end of the other lifting plate away from the die lip, and a motor is installed on one of the lifting plates, 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 to cool it, so that the cooling water in the cooling water tank can effectively take away the heat in the material, thereby cooling the inside of the material and ensuring that the inside of the material can reach a state of initial solidification. This process ensures the overall cooling uniformity of the material.

[0026] The second hydraulic cylinder can control the spacing of the two lifting plates to be the same as the spacing of the adjustment plate, ensuring that during the cooling process of the material, the lifting plates can be flexibly adjusted according to the thickness of the material. The active roller is driven by a motor, which can not only keep the material moving at a constant speed during the cooling process, but also control the movement speed of the material to adjust the cooling time in conjunction with the adjustment of the melt pump. This design allows the cooling process to be consistent with the overall rhythm of the production line.

[0027] Optionally, the three-stage cooling device includes a bottom support seat and a top mounting seat, the bottom support seat is provided with a plurality of air inlets, a plurality of exhaust pipes are installed in the bottom support seat and on the top mounting seat, and each of the exhaust pipes is provided with a plurality of exhaust ports.

[0028] By adopting the above technical solutions, the design of multiple exhaust pipes realizes functions such as multi-point exhaust, up and down two-way cooling and forced convection, further improving the efficiency and uniformity of the material cooling process. It can effectively prevent heat accumulation or uneven cooling of the material during the cooling process, ensuring that the material achieves the ideal cooling effect in the final rigid stage.

[0029] In summary, the present application includes at least one of the following beneficial technical effects: 1. A slide groove is set inside the die lip, and a sliding plate is used to separate the slide groove into a first oil chamber and a second oil chamber to realize hydraulic control of the positions of the two adjustment plates. By injecting hydraulic oil into the first oil chamber and the second oil chamber respectively, the movement of the adjustment plates can be accurately controlled, so that the spacing between the adjustment plates can be flexibly adjusted, and the extruded material is extruded from between the two adjustment plates to ensure the uniformity of the plate thickness; 2. The oil pressure in the first oil chamber and the second oil chamber can be dynamically adjusted according to the pressure change of the molten material (for example, by removing 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 state.) 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 the stability of the pressure of the material during extrusion, prevent excessive pressure accumulation from causing deformation of the die lip or fluctuation in the thickness of the sheet, and thus achieve precise control of the sheet thickness and improve the surface smoothness of the sheet; 3. The design of the first annular cooling channel can effectively control the temperature of the hydraulic oil, avoid pressure fluctuations caused by thermal expansion of the hydraulic oil, and thus maintain stable feedback of the first pressure sensor and the second pressure sensor, avoiding the position deviation of the adjustment plate caused by unstable pressure during the extrusion process. This ensures the uniformity of the sheet thickness and surface finish; 4. The first stage cooling assembly first allows the surface of the extruded material to quickly reach a preliminary solidification state to prevent deformation or surface defects in the subsequent processing; the second stage cooling assembly further reduces the material temperature, allowing the interior of the material to gradually solidify and achieve an internally stable structure; finally, the third stage cooling assembly cools the material to the final rigid stage. The hierarchical control of multi-stage cooling 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 that its internal structure is uniform and stable. This gradual cooling method can effectively reduce the occurrence of cracks, deformation and other problems in the product, thereby ensuring that the physical properties of the entire sheet meet the ideal requirements. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0031] Figure 2 It is a schematic diagram of the structure of the heating channel and the flow chamber used to reflect the embodiment of the present application.

[0032] Figure 3 yes Figure 2 Enlarged schematic diagram of part A.

[0033] Figure 4 It is a structural schematic diagram of an embodiment of the present application for reflecting a liquid inlet, a liquid outlet, an oil filling port and an oil outlet.

[0034] Figure 5 It is a structural schematic diagram of an embodiment of the present application for reflecting a primary cooling component.

[0035] Figure 6 It is a schematic diagram of the structure of the embodiment of the present application for reflecting the liquid injection channel and the second annular cooling channel.

[0036] Figure 7It is a schematic diagram of the structure of the motor, the liquid injection port and the liquid discharge port used in the embodiment of the present application.

[0037] Figure 8 It is a schematic diagram of the structure of the air inlet and the exhaust pipe used in the embodiment of the present application.

[0038] Description of reference numerals: 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 injection port; 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 pressurizing port; 37, second pressurizing port; 38, support plate; 39, sealing strip; 310, first annular cooling channel; 313, liquid inlet; 314, liquid outlet; 41, first pressure sensor; 42, second pressure sensor; 43, first pressure sensor; 44, second pressure sensor; 45, first pressure sensor; 46, first pressure sensor; 47, second pressure sensor; 48, first pressure sensor; 49, second pressure sensor; 50, first pressure sensor; 51, first pressure sensor; 52, first pressure sensor; 53, second pressure sensor; 54, first pressure sensor; 55, first pressure sensor; 56, first pressure sensor; 57, second pressure sensor; 58, first pressure sensor; 59, second pressure sensor; 60, first pressure sensor; 61, first pressure sensor; 62, first pressure sensor; 63, first pressure sensor; 64, second pressure sensor; 65, first pressure sensor; 66, first pressure sensor; 67, second pressure sensor; 68, first pressure sensor; 69, first pressure sensor; 70, first pressure sensor; 71, first pressure sensor; 72, first pressure sensor; 73, second pressure sensor; 74, first pressure sensor; 75, first pressure sensor; 76, first pressure sensor; 77, second pressure sensor; 78 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. Injection channel; 54. Connector; 55. Injection pipe; 6. Secondary cooling assembly; 61. Conveyor platform; 62. Lifting plate; 621. Cooling water trough; 622. Injection port; 623. Drain 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 DESCRIPTION

[0039] The following is combined with Figure 1-8 This application is described in further detail.

[0040] The embodiment of the present application discloses a single-stage double-helix PET foam board extrusion device.

[0041] like Figure 1 and Figure 2 The single-stage double-screw PET foam board 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, the second connecting pipe 12 is connected to a melt pump 8, the melt pump 8 is connected to a first connecting pipe 11, the first connecting pipe 11 is connected to two mold bodies 2, and the two mold bodies 2 have flow grooves 21 opened and closed on opposite sides, and the two flow grooves 21 together form an extrusion channel. In addition, two flow chambers 22 are respectively opened on opposite sides of the two mold bodies 2, and the flow chambers 22 are semi-cylindrical grooves. A die lip 3 is installed at one end of the mold body 2 away from the first connecting pipe 11, and the two die lips 3 are arranged opposite to each other.

[0042] like Figure 3 and Figure 4, a heating channel 23 is provided in the die body 2, and the heating channels 23 of the two die bodies 2 jointly form a spiral channel. The heating channel 23 and the extrusion channels between the two die bodies 2 are independently arranged. An oil injection port 24 is provided on one die body 2, and an oil outlet 25 is provided on the other die body 2. Both the oil outlet 25 and the oil injection port 24 are communicated with the heating channel 23 on the corresponding die body 2.

[0043] Chutes 31 are provided in both die lips 3. The chutes 31 penetrate to the opposite sides of the two die lips 3. A sliding plate 32 is slidably arranged in the chutes 31. The sliding plate 32 is connected with an adjusting plate 33. One end of the adjusting plate 33 extends out of the die lip 3. The sliding plate 32 divides the chutes 31 into a first oil cavity 311 and a second oil cavity 312. The first oil cavity 311 penetrates to the opposite sides of the two die lips 3. At the top of the die lip 3, there is a first hydraulic cylinder 34. The piston rod of the first hydraulic cylinder 34 penetrates into the die lip 3. The piston rod of the first hydraulic cylinder 34 is connected with an abutting plate 35. The longitudinal section of the abutting plate 35 is in a U shape. The abutting plate 35 can extend into the second oil cavity 312 and abut against the top of the adjusting plate 33. The die lip 3 is provided with a first pressurizing port 36 communicated with the first oil cavity 311 and a second pressurizing port 37 communicated with the second oil cavity 312. On the side of the first oil cavity 311 facing the sliding plate 32, a support plate 38 is arranged. The support plate 38 is arranged along the length direction of the adjusting plate 33. A sealing strip 39 is arranged on the top surface of the support plate 38, and the sealing strip 39 is also tightly abutted against the circumferential surface of the adjusting plate 33.

[0044] As Figure 3 , Figure 4 and Figure 5 , a first annular cooling channel 310 is provided in the die lip 3. The first annular cooling channel 310 is arranged around the chute 31. The first annular cooling channel 310 and the chute 31, the first pressurizing port 36 and the second pressurizing port 37 are independently arranged. The die lip 3 is provided with a liquid inlet 313 and a liquid outlet 314 communicated with the first annular cooling channel 310.

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

[0046] As Figure 1 and Figure 4, a primary cooling assembly 5 is provided on the side of the adjustment plate 33 away from the die body 2, a secondary cooling assembly 6 is provided on the side of the die lip 3 away from the die body 2, a tertiary cooling assembly 7 is provided on the side of the secondary cooling assembly 6 away from the die lip 3, the primary cooling assembly 5 is used to cool the extruded material to the initial solidification state of the surface, the secondary cooling assembly 6 is used to cool the extruded material to the initial solidification state of the inside, 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 adjustment plates 33, first inject hydraulic oil into the first oil chamber 311, and the displacement sensor 43 detects the distance between the adjustment plate 33 and the top wall of the second oil chamber 312. After the adjustment plate 33 reaches the set position, inject hydraulic oil 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, continue to pressurize the first oil chamber 311 and the second oil chamber 312, so that the first oil chamber 311 and the second oil chamber 312 have higher oil pressure, so that the adjustment plate 33 is in a fixed state.

[0048] Then start the twin-screw extruder 1 and the melt pump 8, inject hot oil into the heating channel 23, inject coolant into the first annular cooling channel 310, and when the material is extruded from between the two adjustment 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 removing 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 equilibrium state, and the material rate is adjusted by adjusting the melt pump 8, thereby changing the pressure of the material on the adjustment plate 33. Then the material passes through the primary cooling component 5, the secondary cooling component 6 and the tertiary cooling component 7 in sequence, and enters the cutting device for cutting after being formed.

[0049] The sliding plate 32 is used to separate the slide 31 into a first oil chamber 311 and a second oil chamber 312, so as to realize hydraulic control of the positions of the two adjustment plates 33. By injecting hydraulic oil into the first oil chamber 311 and the second oil chamber 312 respectively, the movement of the adjustment plates 33 can be accurately controlled, so that the spacing between the adjustment plates 33 can be flexibly adjusted, and the extruded material is extruded from between the two adjustment plates 33 to ensure the uniformity of the plate thickness; During the extrusion process, the pressure of the material on the adjusting plate 33 can be monitored in real time through the pressure feedback system in the hydraulic system to ensure the stability of the pressure of the material during extrusion and 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 smoothness of the sheet.

[0050] Hot oil is injected into the heating channel 23 to provide a continuous heat source for the mold body 2, so that the material is not easily cooled down due to a long transmission distance or a temperature change in the surrounding environment during the transmission process, thereby ensuring good material fluidity.

[0051] The first annular cooling channel 310 can effectively control the temperature of the hydraulic oil, avoid pressure fluctuations caused by thermal expansion of the hydraulic oil, and thus maintain stable feedback of the first pressure sensor 41 and the second pressure sensor 42, avoiding position deviation of the adjustment plate 33 caused by unstable pressure during the extrusion process. This ensures the uniformity of the thickness and surface finish of the sheet.

[0052] The first-stage cooling component 5 first allows the surface of the extruded material to quickly reach a preliminary solidification state to prevent deformation or surface defects in the subsequent processing; the second-stage cooling component 6 further reduces the material temperature, allowing the interior of the material to gradually solidify and achieve an internally stable structure; finally, the third-stage cooling component 7 cools the material to the final rigid stage. The hierarchical control of multi-stage cooling 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 that its internal structure is uniform and stable. This gradual cooling method can effectively reduce the occurrence of cracks, deformation and other problems in the product, thereby ensuring that the physical properties of the entire sheet meet the ideal requirements.

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

[0054] like Figure 2 and Figure 7The secondary cooling assembly 6 includes a conveying platform 61, on which two lifting plates 62 are installed, and the two lifting plates 62 are arranged opposite to each other. A second hydraulic cylinder 63 for controlling the relative movement of the two lifting plates 62 is arranged on the conveying platform 61, and one second hydraulic cylinder 63 is installed on the top of the conveying platform 61, and the other second hydraulic cylinder 63 is installed on the bottom of the conveying platform 61. A cooling water tank 621 is provided in the lifting plate 62, and a liquid injection port 622 and a liquid discharge port 623 connected to the cooling water tank 621 are provided on the lifting plate 62. An active roller 64 is installed at one end of one lifting plate 62 away from the die lip 3, and a passive roller 65 is installed at the other end of the other lifting plate 62 away from the die lip 3. A motor 66 is installed on one lifting plate 62, and the motor 66 is connected to the active roller 64; like Figure 8 The three-stage cooling assembly 7 includes a bottom support seat 71 and a top mounting seat 72. The bottom support seat 71 is provided with a plurality of air inlets 711. A plurality of exhaust pipes 73 are installed in the bottom support seat 71 and on the top mounting seat 72. Each exhaust pipe 73 is provided with a plurality of exhaust ports 731. The exhaust pipes 73 are arranged along the width direction of the die lip 3, and the exhaust pipes 73 are arranged equidistantly along the length direction of the bottom support seat 71.

[0055] The circumference of the cooling roller 51 is tangent to the end face of the adjustment plate 33, which means that when the material is extruded from the die lip 3, it directly contacts the circumference of the cooling roller 51. The cooling roller 51 can quickly take away the heat from the surface of the extruded material, allowing the surface of the material to quickly cool 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 occurrence 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 51 can ensure uniform cooling and avoid surface stress or wrinkles caused by uneven cooling.

[0056] The lifting plate 62 is relative to the surface of the extruded material, and can be in contact with the surface of the material for cooling, so that the cooling water in the cooling water tank 621 can effectively take away the heat in the material, thereby cooling the inside of the material to ensure that the inside of the material can reach a state of preliminary solidification. This process ensures the overall cooling uniformity of the material.

[0057] The second hydraulic cylinder 63 can control the spacing between the two lifting plates 62 to be the same as the spacing between the adjustment plates 33, ensuring that during the cooling process of the material, the lifting plates 62 can be flexibly adjusted according to the thickness of the material. The active roller 64 is driven by the motor 66, which can not only keep the material moving at a constant speed during the cooling process, but also control the moving speed of the material to adjust the cooling time in conjunction with the adjustment of the melt pump 8. This design allows the cooling process to be consistent with the overall rhythm of the production line.

[0058] The design of multiple exhaust pipes 73 realizes functions such as multi-point exhaust, up and down two-way cooling and forced convection, which further improves the efficiency and uniformity of the material cooling process. It can effectively prevent heat accumulation or uneven cooling of the material during the cooling process, ensuring that the material achieves the ideal cooling effect in the final rigid stage.

[0059] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A single-stage double-screw PET foam sheet extrusion device, characterized in that: The invention comprises two die bodies (2), one end of each of the die bodies (2) is connected to a die lip (3), the two die bodies (2) are arranged opposite to each other, the two die lips (3) are arranged opposite to each other, the two die bodies (2) are commonly connected to a twin-screw extruder (1), a slide groove (31) is provided in each of the two die lips (3), the slide groove (31) is connected to the opposite side of the two die lips (3), a sliding plate (32) is slidably provided in the slide groove (31), the sliding plate (32) is connected to an adjusting plate (33), one end of the adjusting plate (33) extends out of the die lip (3), and the sliding plate (32) divides the slide groove (31) into a first oil chamber (311) and a second oil chamber (312), the adjustment plate (33) extends out of the first oil chamber (311) to extend out of the die lip (3), the die lip (3) is connected to a first hydraulic cylinder (34), the first hydraulic cylinder (34) is connected to a contact plate (35), the contact plate (35) can extend into the second oil chamber (312) and contact with the adjustment plate (33), the two ends of the two die bodies (2) away from the die lip (3) are commonly connected to a twin-screw extruder (1), and the die lip (3) is provided with a first pressurizing port (36) communicating with the first oil chamber (311) and a second pressurizing port (37) communicating with the second oil chamber (312).

2. The single-stage double-screw PET foam sheet extrusion device according to claim 1, characterized in that: The ends of the two die bodies (2) away from the die lip (3) are commonly connected to a first connecting pipe (11), 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), and flow chambers (22) are provided on opposite sides of the two die bodies (2), and the flow chambers (22) are connected to the extrusion channels between the two die bodies (2).

3. The single-stage double-screw PET foam sheet extrusion device according to claim 1, characterized in that: 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), a detection hole (351) is opened on the abutment plate (35), and the displacement sensor (43) detects the distance between the adjustment plate (33) and the top wall of the second oil chamber (312) through the detection hole (351).

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

5. The single-stage double-screw PET foam sheet extrusion device according to claim 1, characterized in that: A first annular cooling channel (310) is provided in the die lip (3), the first annular cooling channel (310) is arranged around the slide groove (31), the first annular cooling channel (310) and the slide groove (31) are arranged independently of each other, and a liquid inlet (313) and a liquid outlet (314) which are connected to the first annular cooling channel (310) are provided on the die lip (3).

6. The single-stage double-screw PET foam board extrusion device according to claim 1, characterized in that: A support plate (38) is provided in the first oil chamber (311) on a side facing the sliding plate (32); the support plate (38) is provided along the length direction of the adjustment plate (33); and a sealing strip (39) is provided on the top surface of the support plate (38).

7. The single-stage double-screw PET foam sheet extrusion device according to claim 1, characterized in that: A primary cooling component (5) is arranged on the side of the adjustment plate (33) facing away from the die body (2), a secondary cooling component (6) is arranged on the side of the die lip (3) facing away from the die body (2), and a tertiary cooling component (7) is arranged on the side of the secondary cooling component (6) facing away from the die 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 a final rigidity stage.

8. The single-stage double-screw PET foam board extrusion device according to claim 7, characterized in that: The primary cooling assembly (5) comprises a cooling roller (51), and a bracket (52) is installed at one end of the adjustment plate (33) extending out of the die lip (3), and the bracket (52) is rotatably connected to a support shaft (53). The cooling roller (51) is sleeved and fixed on the support shaft (53), and a liquid injection channel (531) is provided in the support shaft (53). The cooling roller (51) is provided with a second annular cooling channel (511), and the liquid injection channel (531) is connected to the second annular cooling channel (511). The end of the bracket (52) is connected to a connector (54), and the connector (54) is connected to an injection pipe (55). The connector (54) is connected to the support shaft (53), and the end face of the connector (54) is connected to the end face of the cooling roller (51), and the peripheral surface of the cooling roller (51) and the peripheral surface of the connector (54) are both tangent to the extended surface of the end face of the adjustment plate (33).

9. The single-stage double-screw PET foam board extrusion device according to claim 7, characterized in that: The secondary cooling assembly (6) comprises a conveying platform (61), on which two lifting plates (62) are mounted, the two lifting plates (62) being arranged opposite to each other, and on which a second hydraulic cylinder (63) for controlling the relative movement of the two lifting plates (62) is mounted, a cooling water trough (621) is provided in the lifting plates (62), and the lifting plates (62) are provided with a liquid injection port (622) and a liquid discharge port (623) connected to the cooling water trough (621), an active roller (64) is mounted on one end of the lifting plates (62) away from the die lip (3), and a passive roller (65) is mounted on the other end of the lifting plates (62) away from the die lip (3), and a motor (66) is mounted on one of the lifting plates (62), and the motor (66) is connected to the active roller (64).

10. The single-stage double-screw PET foam board extrusion device according to claim 7, characterized in that: The three-stage cooling assembly (7) comprises a bottom support seat (71) and a top mounting seat (72), the bottom support seat (71) being provided with a plurality of air inlets (711), a plurality of exhaust pipes (73) being installed inside the bottom support seat (71) and on the top mounting seat (72), and each of the exhaust pipes (73) being provided with a plurality of exhaust ports (731).

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