Multi-stage temperature control extrusion equipment and method for PVC (polyvinyl chloride) film

Abstract

The invention relates to the technical field of PVC film processing and forming, and discloses a multi-stage temperature control extrusion device and method for a PVC film, the multi-stage temperature control extrusion device comprises a supporting base plate, a spiral extrusion part, a multi-stage temperature control part and an interval connection heat preservation part, and a control cabinet is arranged on one side of the supporting base plate; the spiral extrusion part is arranged at the top of the supporting base plate; the multistage temperature control parts are arranged on the outer side of the spiral extrusion part in a sleeving manner at equal intervals; and the interval connection heat preservation parts are respectively arranged between the outer side of the spiral extrusion part and the multi-stage temperature control part. According to the invention, independent temperature control is carried out on different working intervals such as feed preheating, compression heating, plasticizing temperature equalization and the like in the extrusion process, and each interval can be matched with an exclusive temperature standard of a corresponding treatment stage of a PVC raw material, so that the problem that the requirements of each stage cannot be considered under a single temperature control mode is avoided; a suitable temperature environment is provided for the whole process from feeding to melt forming of raw materials, and heat transfer and loss of adjacent working intervals can be reduced by combining an interval connection heat preservation structure.

Description

Technical Field

[0001] This invention relates to the field of PVC film processing and molding technology, specifically to a multi-stage temperature-controlled extrusion device and method for PVC film. Background Technology

[0002] Polyvinyl chloride (PVC) film is widely used in packaging, construction, electronics, medical and other fields due to its excellent corrosion resistance, insulation, processability and cost advantages. Extrusion molding is one of the core processes in PVC film production. The principle is to mix PVC raw materials with relevant additives and feed them into the extrusion cylinder of the extrusion equipment. The rotating screw extrusion blades push the raw materials to achieve conveying, compression and plasticization, and finally extrude them into film products through the die.

[0003] Temperature control is one of the key factors determining product quality during the extrusion molding process of PVC film. The plasticization process of PVC raw materials is extremely sensitive to temperature changes, and different stages (such as feed preheating, compression heating, plasticizing homogenization, and melt stabilization) require matching temperature ranges: the feed stage needs to be controlled at a lower temperature to avoid premature adhesion and blockage of the feed inlet; the compression heating stage needs to gradually increase the temperature to achieve initial softening of the raw materials; the plasticizing homogenization stage needs to maintain a stable high-temperature environment to ensure complete plasticization and melting of the raw materials, and uniform melt temperature; the melt stabilization stage requires precise temperature control to ensure stable melt flow and avoid problems such as uneven film thickness and decreased mechanical properties caused by temperature fluctuations.

[0004] However, conventional PVC film extrusion equipment currently on the market still has many shortcomings in temperature control: On the one hand, most equipment adopts an integrated or a few-stage temperature control structure, which makes it difficult to achieve independent and precise temperature control for different working zones of the extrusion cylinder. Often, a single temperature control parameter cannot adapt to the plasticizing requirements of each stage, resulting in incomplete or over-plasticization of the raw material, which in turn affects the forming quality of the PVC film and causes defects such as rough film surface, bubbles, and excessive thickness deviation. On the other hand, the connection between the working zones of the extrusion cylinder lacks an effective heat preservation structure, which easily leads to heat loss and sudden temperature gradient changes, making the melt unstable during the transition between zones and further aggravating the fluctuation of product quality.

[0005] Based on the current state of the industry, how to develop a PVC film extrusion equipment and method that can achieve temperature control in each working zone, effectively solve the problem of temperature loss at the connection between zones, and improve the temperature control response speed and detection accuracy has become a technical problem that urgently needs to be solved in the current PVC film production field, and also provides important practical needs and technical guidance for the research of this invention. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-stage temperature-controlled extrusion device and method for PVC film, which solves the technical problems of traditional PVC film extrusion equipment, such as difficulty in temperature control of each working zone during extrusion and the tendency for temperature loss at the zone connection points to cause unstable melt state, thus affecting the quality of PVC film forming. The invention achieves the goal of regulating the temperature of each working zone during the extrusion process and effectively insulating the zone connection points, ensuring the uniformity and stability of the extruded melt, and improving the quality of PVC film forming and production stability.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a multi-stage temperature-controlled extrusion device and method for PVC film, comprising a support substrate, a spiral extrusion section, a multi-stage temperature control section, and an interval connecting insulation section. A control cabinet is disposed on one side of the support substrate; the spiral extrusion section is disposed on the top of the support substrate; the multi-stage temperature control section is equidistantly sleeved on the outside of the spiral extrusion section; the interval connecting insulation section is disposed on the outside of the spiral extrusion section and between the multi-stage temperature control section, respectively. The multi-stage temperature control section can effectively control the temperature of the corresponding working interval through sensors, a heating unit, and a cooling unit, thus corresponding to the temperature of different intervals.

[0008] Preferably, the spiral extrusion section specifically includes: an extrusion cylinder disposed on the top of the support substrate; a drive motor fixedly installed on the outer wall of one end of the extrusion cylinder; and a feed hopper connected to the outer wall of the extrusion cylinder.

[0009] Preferably, the interior of the extrusion cylinder is provided with a feeding preheating zone, a compression heating zone, a plasticizing uniform temperature zone, a melt pressure stabilizing zone, an outlet transition zone, and a die head adaptation zone. The output end of the drive motor is fixedly connected to a rotating extrusion rod, and a spiral extrusion blade is fixedly sleeved on the outer wall of the rotating extrusion rod. A melt temperature sensor is provided on the outer side of the die head adaptation zone.

[0010] Preferably, the multi-stage temperature control unit specifically includes: connecting blocks, which are circumferentially and equidistantly fixed on the outer wall of the extrusion cylinder; a temperature sensor, which is disposed between the connecting blocks; and a heating plate, which is circumferentially and equidistantly fixed on the outer wall of the extrusion cylinder.

[0011] Preferably, the sensing end of the temperature sensor 1 movably penetrates the outer wall of the extrusion cylinder and extends into the interior of the extrusion cylinder. A cooling sleeve is fixedly connected to the outer wall of the connecting block on the side away from the extrusion cylinder, and the cooling sleeve is fitted onto the outer wall of the heating plate.

[0012] Preferably, a second temperature sensor is fixedly installed on the outer wall of the cooling jacket, and a spiral cooling pipe is provided inside the cooling jacket. The two ends of the spiral cooling pipe movably penetrate the inner wall of the cooling jacket and extend to the outer wall of the cooling jacket. An input bend and an output bend are respectively connected to the two ends of the spiral cooling pipe.

[0013] Preferably, the interval connection insulation part specifically includes: an insulation sleeve, which is fixedly sleeved on the outer wall of the extrusion cylinder; the outer wall of the insulation sleeve is symmetrically fixedly equipped with support legs, the inner wall of the insulation sleeve is symmetrically provided with flow-slowing baffles, and the flow-slowing baffles are circumferentially and equidistantly provided with flow-slowing holes; the interior of the insulation sleeve is provided with a liquid inlet cavity, a flow-slowing cavity and a liquid outlet cavity; the two outer walls of the insulation sleeve are respectively connected to an input pipe and an output pipe, the input pipe is connected to the liquid inlet cavity and the output pipe is connected to the liquid outlet cavity.

[0014] Another technical problem to be solved by the present invention is to provide a method for multi-stage temperature-controlled extrusion of PVC film, comprising the following steps:

[0015] Step 1: Preset temperature control parameters. According to the process requirements of PVC film extrusion, input the target temperature of each working zone into the control device, and clarify the temperature standards of different zones such as feed preheating, compression heating, plasticizing uniform temperature, melt pressure stabilization, outlet transition and die head adaptation. At the same time, set the start threshold of the heating unit, the intervention conditions of the cooling unit and the allowable range of temperature fluctuation.

[0016] Step 2: Start the heating unit for preheating. After the equipment is turned on, the heating unit starts working, preheating each section of the extrusion cylinder synchronously or in stages, so that the temperature of each section gradually approaches the preset target value, providing a suitable initial temperature environment for the subsequent processing of PVC raw materials.

[0017] Step 3: Start the temperature monitoring system. While the heating unit is working, start each temperature sensor to collect the actual temperature of each section inside the extrusion cylinder and the outer wall temperature of the cooling structure in real time. The collected temperature data is continuously fed back to the control device to form a closed loop of temperature monitoring.

[0018] Step 4: Heating stage adjustment. The control device compares the collected actual temperature with the preset target temperature. If the actual temperature in a certain range is lower than the target temperature, the heating unit in the corresponding range increases the heating power until the temperature in that range rises to the target value. If the temperature is close to the target value, the heating unit is adjusted to reduce the power to avoid a sudden temperature rise.

[0019] Step 5: Dynamic Control During Cooling. When the temperature sensor detects that the temperature in a certain area exceeds the preset target value or that the temperature rises too rapidly, the control device immediately activates the cooling system for the corresponding area. Cooling medium is introduced through the cooling pipes inside the cooling structure, and the circulation of the cooling medium removes excess heat. Simultaneously, based on temperature feedback data, the input flow rate and velocity of the cooling medium are adjusted to precisely control the cooling rate, ensuring that the temperature quickly returns to the target range and remains stable.

[0020] Step Six: Auxiliary Insulation for Inter-zone Connections. At the connection points of each temperature-controlled zone, activate the insulation system. A constant-temperature protective layer is formed through the circulation of the medium inside the insulation structure. The liquid medium enters the inlet cavity inside the insulation structure through the input pipeline. After the flow rate is slowed down by the slow-flow structure, it enters the slow-flow cavity to fully exert the insulation effect. Then, it is discharged from the output pipeline through the outlet cavity, reducing temperature transfer interference between adjacent zones and avoiding sudden temperature changes at the zone connection points.

[0021] Step Seven: Dynamic Stabilization Throughout the PVC Film Extrusion Process. Temperature sensors continuously monitor the temperature of each zone and the cooling structure during the entire PVC film extrusion process. Based on real-time feedback data, the control device dynamically adjusts the heating power of the heating unit and the cooling medium flow rate of the cooling system, while maintaining the stable operation of the insulation system. If temperature fluctuations exceed the allowable range, the corresponding adjustment mechanism is immediately triggered to ensure that the temperature of each working zone remains stable within the preset process range. This ensures that all stages, including PVC raw material feeding, compression, plasticizing, and melt pressure stabilization, are under suitable temperature conditions, ultimately guaranteeing the extrusion quality of the PVC film.

[0022] This invention provides a multi-stage temperature-controlled extrusion apparatus and method for PVC film. It has the following beneficial effects:

[0023] (1) This invention implements independent temperature control for different working zones such as feeding preheating, compression heating and plasticizing uniform temperature during the extrusion process. Each zone can match the exclusive temperature standard of the corresponding processing stage of PVC raw materials, avoiding the problem that the needs of each stage cannot be taken into account under a single temperature control mode. It provides a suitable temperature environment for the entire process of raw materials from feeding to melt molding. Combined with the zone connection insulation structure, it can reduce the heat transfer and loss of adjacent working zones.

[0024] (2) The present invention forms a heat insulation barrier by using a heat insulation sleeve, which effectively blocks the heat from penetrating between adjacent working areas, and avoids temperature fluctuations in one area from interfering with the temperature control accuracy of other areas. This lays the foundation for the zoned control of the multi-level temperature control unit. Through the internal heat insulation medium circulation and slow flow design, the zone connection is kept in a stable constant temperature environment, preventing the temperature drop caused by heat loss. This ensures that the PVC raw material is always at a suitable temperature during the zone transition, avoiding problems such as insufficient plasticization and abnormal melt flow. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention;

[0026] Figure 2 This is a partial cross-sectional view of the spiral extrusion section of the present invention;

[0027] Figure 3 This is a partial view of the multi-stage temperature control unit of the present invention;

[0028] Figure 4 This is a partial cross-sectional view of the multi-stage temperature control unit of the present invention.

[0029] In the diagram: 1 Support base plate, 2 Control cabinet, 3 Spiral extrusion section, 311 Drive motor, 312 Extrusion cylinder, 313 Rotating extrusion rod, 314 Spiral extrusion blade, 315 Feed preheating zone, 316 Compression heating zone, 317 Plasticizing uniform temperature zone, 318 Melt pressure stabilization zone, 319 Outlet transition zone, 3111 Die head adaptation zone, 3112 Melt temperature sensor, 3113 Feed hopper, 4 Multi-stage temperature control section, 411 Connecting block, 412 Temperature sensor one, 413 Heating plate, 414 Cooling jacket, 415 Temperature sensor two, 416 Spiral cooling pipe, 417 Input bend, 418 Output bend, 5 Interval connection insulation section, 511 Insulation jacket, 512 Support leg, 513 Output pipe, 514 Input pipe, 515 Slow flow baffle, 516 Liquid inlet cavity, 517 Slow flow cavity, 518 Liquid outlet cavity. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0032] Example 1:

[0033] Based on the existing problems of traditional PVC film extrusion equipment, such as difficulty in achieving temperature control in each working zone of the extrusion process and the tendency for temperature loss at the zone connections to lead to unstable melt conditions and thus affect the quality of PVC film forming, the present invention provides a preferred embodiment of a multi-stage temperature-controlled extrusion device and method for PVC film, for example... Figure 1-4 The image shows a multi-stage temperature-controlled extrusion device and method for PVC film, comprising a support base plate 1, a spiral extrusion section 3, a multi-stage temperature control section 4, and an interval connecting insulation section 5. A control cabinet 2 is disposed on one side of the support base plate 1; the spiral extrusion section 3 is disposed on the top of the support base plate 1; the multi-stage temperature control section 4 is equidistantly sleeved on the outside of the spiral extrusion section 3; the interval connecting insulation sections 5 are respectively disposed on the outside of the spiral extrusion section 3 and between the multi-stage temperature control section 4. The multi-stage temperature control section 4 can effectively control the temperature of the corresponding working interval through sensors, heating units, and cooling units, corresponding to the temperature of different intervals.

[0034] The spiral extrusion section 3 specifically includes: an extrusion cylinder 312, which is disposed on the top of the support base plate 1; a drive motor 311, which is fixedly installed on the outer wall of one end of the extrusion cylinder 312; and a feed hopper 3113, which is connected to the outer wall of the extrusion cylinder 312.

[0035] The interior of the extrusion cylinder 312 is provided with a feeding preheating zone 315, a compression heating zone 316, a plasticizing uniform temperature zone 317, a melt pressure stabilizing zone 318, an outlet transition zone 319, and a die head adaptation zone 3111. The output end of the drive motor 311 is fixedly connected to a rotating extrusion rod 313. The outer wall of the rotating extrusion rod 313 is fixedly fitted with a spiral extrusion blade 314. A melt temperature sensor 3112 is provided on the outside of the die head adaptation zone 3111.

[0036] Furthermore, in this embodiment, PVC raw material is poured into the feed hopper 3113 and enters the extrusion cylinder 312 through the feed hopper 3113; the drive motor 311 is started by the control cabinet 2, and the output end of the drive motor 311 drives the rotating extrusion rod 313 to rotate, and the spiral extrusion blade 314 on the outer wall of the rotating extrusion rod 313 rotates accordingly, pushing the PVC raw material to move gradually along each working zone inside the extrusion cylinder 312.

[0037] Example 2:

[0038] Based on Example 1, a preferred embodiment of the multi-stage temperature-controlled extrusion equipment and method for PVC film provided by the present invention is as follows: Figure 1-4 As shown: The multi-stage temperature control unit 4 specifically includes: a connecting block 411, which is circumferentially and equidistantly fixed on the outer wall of the extrusion cylinder 312; a temperature sensor 412, which is disposed between the connecting blocks 411; and a heating plate 413, which is circumferentially and equidistantly fixed on the outer wall of the extrusion cylinder 312.

[0039] The sensing end of the temperature sensor 412 moves through the outer wall of the extrusion cylinder 312 and extends into the interior of the extrusion cylinder 312. A cooling sleeve 414 is fixedly connected to the outer wall of the connecting block 411 on the side away from the extrusion cylinder 312. The cooling sleeve 414 is sleeved on the outer wall of the heating plate 413.

[0040] A temperature sensor 415 is fixedly installed on the outer wall of the cooling jacket 414. A spiral cooling pipe 416 is provided inside the cooling jacket 414. The two ends of the spiral cooling pipe 416 movably penetrate the inner wall of the cooling jacket 414 and extend to the outer wall of the cooling jacket 414. An input bend pipe 417 and an output bend pipe 418 are respectively connected to the two ends of the spiral cooling pipe 416.

[0041] Furthermore, in this embodiment, the heating plate 413 of the multi-stage temperature control unit 4 is activated by the control cabinet 2. The heating plate 413 is fixed to the outer wall of the extrusion cylinder 312 by the connecting block 411, and heats up each section of the extrusion cylinder 312. At the same time, the sensing end of the temperature sensor 412, which is set between the connecting blocks 411, penetrates the outer wall of the extrusion cylinder 312, collects the actual temperature of each section inside the extrusion cylinder 312 in real time, and feeds the data back to the control cabinet 2. The cooling sleeve 414 is fitted on the outer wall of the heating plate 413, and the temperature sensor 415 on its outer wall collects the temperature data of the heating plate 413 and the cooling sleeve 414 in real time, and also feeds it back to the control cabinet 2. This provides a suitable temperature environment for the entire process from raw material feeding to melt forming. Combined with the section connection insulation structure, the heat transfer and loss between adjacent working sections can be reduced, so that the temperature of each section remains relatively independent, avoiding temperature control deviation caused by mutual interference between section temperatures, and further improving the reliability of the overall temperature control system.

[0042] Example 3:

[0043] Based on Examples 1 and 2, a preferred embodiment of the multi-stage temperature-controlled extrusion equipment and method for PVC film provided by the present invention is as follows: Figure 1-4 As shown: The section connection insulation part 5 specifically includes: an insulation sleeve 511, which is fixedly sleeved on the outer wall of the extrusion cylinder 312; support legs 512 are symmetrically fixedly installed on the outer wall of the insulation sleeve 511; slow flow baffles 515 are symmetrically arranged on the inner wall of the insulation sleeve 511; slow flow holes are equidistantly opened on the slow flow baffles 515; the interior of the insulation sleeve 511 is provided with a liquid inlet cavity 516, a slow flow cavity 517 and a liquid outlet cavity 518; an input pipe 514 and an output pipe 513 are respectively connected to the outer walls on both sides of the insulation sleeve 511; the input pipe 514 is connected to the liquid inlet cavity 516 and the output pipe 513 is connected to the liquid outlet cavity 518.

[0044] Furthermore, in this embodiment, the insulation medium output from the external liquid medium heating device enters the liquid inlet cavity 516 of the insulation sleeve 511 through the inlet pipe 514, and slowly flows into the slow flow cavity 517 through the slow flow holes on the slow flow baffle 515, achieving uniform distribution of the insulation medium. Subsequently, it flows back from the liquid outlet cavity 518 to the external liquid medium heating device through the outlet pipe 513, forming a circulation of the insulation medium. During this process, the insulation sleeve 511 is stably supported at the designated position by the support leg 512, pre-insulating the section connection of the extrusion cylinder 312, reducing heat loss in this area during subsequent operations. Through the internal insulation medium circulation and slow flow design, the section connection is kept in a stable constant temperature environment, preventing a sudden drop in temperature due to heat loss, ensuring that the PVC raw material is always at a suitable temperature during the section transition, and avoiding problems such as insufficient plasticization and abnormal melt flow.

[0045] This equipment is supported by a support base plate 1 for overall installation. The control cabinet 2 coordinates the operation of the spiral extrusion section 3, the multi-stage temperature control section 4, and the inter-section connecting insulation section 5 to achieve precise extrusion molding of PVC raw materials. The insulation sleeve 511 is connected to an external liquid medium heating device, and the spiral cooling pipe 416 is connected to an external cooling device. The specific working steps are as follows:

[0046] Step 1: Equipment Start-up and Parameter Preset. First, start the equipment through control cabinet 2. Input the target temperature control parameters for each working zone into control cabinet 2, including the temperature standards for the feeding preheating zone 315, compression heating zone 316, plasticizing uniform temperature zone 317, melt pressure stabilization zone 318, outlet transition zone 319, and die head adaptation zone 3111. At the same time, start the external liquid medium heating equipment and external cooling equipment, so that the preheated insulation medium is connected to the inside of the insulation jacket 511 through the input pipe 514, and the spiral cooling pipe 416 is connected to the cooling medium through the input bend pipe 417, completing the preparation work before equipment start-up.

[0047] Step 2: Pre-start of the insulation system. The insulation medium output from the external liquid medium heating equipment enters the liquid inlet cavity 516 of the insulation sleeve 511 through the input pipe 514, and slowly flows into the slow flow cavity 517 through the slow flow holes on the slow flow baffle 515 to achieve uniform distribution of the insulation medium. Then, it flows back to the external liquid medium heating equipment from the liquid outlet cavity 518 through the output pipe 513 to form a circulation of the insulation medium. During this process, the insulation sleeve 511 is stably supported in the designated position by the support leg 512 to pre-insulate the section connection of the extrusion cylinder 312 and reduce heat loss in this area during subsequent operations.

[0048] Step 3: Raw material feeding and extrusion start-up. Pour the PVC raw material into the feed hopper 3113. The raw material enters the extrusion cylinder 312 through the feed hopper 3113. Start the drive motor 311 through the control cabinet 2. The output end of the drive motor 311 drives the rotating extrusion rod 313 to rotate. The spiral extrusion blade 314 on the outer wall of the rotating extrusion rod 313 rotates accordingly, pushing the PVC raw material to move gradually along the working areas inside the extrusion cylinder 312.

[0049] Step 4: Preheating and temperature monitoring of the multi-stage temperature control unit. During the raw material movement, the control cabinet 2 activates the heating plate 413 of the multi-stage temperature control unit 4. The heating plate 413 is fixed to the outer wall of the extrusion cylinder 312 through the connecting block 411 to heat up each section of the extrusion cylinder 312. At the same time, the sensing end of the temperature sensor 412, which is set between the connecting blocks 411, penetrates through the outer wall of the extrusion cylinder 312 to collect the actual temperature of each section inside the extrusion cylinder 312 in real time and feeds the data back to the control cabinet 2. The cooling sleeve 414 is fitted on the outer wall of the heating plate 413, and the temperature sensor 415 on its outer wall collects the temperature data of the heating plate 413 and the cooling sleeve 414 in real time and feeds it back to the control cabinet 2.

[0050] Step 5: Dynamic temperature adjustment and raw material processing. Control cabinet 2 compares the actual temperature fed back by temperature sensor 412 with the preset target temperature: If the temperature of a certain range is lower than the target value, the heating plate 413 in the corresponding area is controlled to increase the heating power and raise the temperature of that range; If the temperature of a certain range is higher than the target value, the external cooling equipment is immediately started. The cooling medium enters the spiral cooling pipe 416 through the input bend 417. The spiral cooling pipe 416 is distributed around the cooling jacket 414, quickly absorbing the excess heat of the heating plate 413. Then the cooling medium flows back to the external cooling equipment through the output bend 418 to achieve temperature adjustment. During this process, the PVC raw material is preheated in the feeding preheating zone 315 of the extrusion cylinder 312, compressed and heated by the spiral extrusion blades 314 in the compression heating zone 316, fully plasticized in the plasticizing uniform temperature zone 317, and maintains a stable melt state in the melt stabilizing zone 318. Finally, it enters the die head adaptation zone 3111 through the outlet transition zone 319.

[0051] Step Six: Final monitoring of melt temperature and extrusion molding. The melt temperature sensor 3112 on the outside of the die head adapter area 3111 collects the temperature data of the PVC melt in real time and feeds it back to the control cabinet 2. If there is a temperature deviation, the control cabinet 2 readjusts the heating plate 413 or cooling system in the corresponding area to ensure that the melt temperature meets the molding requirements. The PVC melt that meets the requirements enters the subsequent molding structure through the die head adapter area 3111 to complete the extrusion molding of the PVC film.

[0052] Step 7: Equipment shutdown and system shutdown. After the PVC film extrusion is completed, stop adding raw materials to the feed hopper 3113. After the raw materials inside the extrusion cylinder 312 are completely extruded, turn off the drive motor 311 through the control cabinet 2. Then turn off the heating plate 413 and the external cooling equipment, and stop the cooling medium circulation of the spiral cooling pipe 416. After the temperature of the extrusion cylinder 312 drops to room temperature, turn off the external liquid medium heating equipment and stop the heat insulation medium circulation of the heat insulation jacket 511 to complete the entire workflow.

[0053] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-stage temperature-controlled extrusion apparatus and method for PVC film, comprising a support substrate (1), a spiral extrusion section (3), a multi-stage temperature control section (4), and an inter-stage connecting insulation section (5), characterized in that, A control cabinet (2) is provided on one side of the support base plate (1); the spiral extrusion section (3) is provided on the top of the support base plate (1); the multi-stage temperature control section (4) is equidistantly sleeved on the outside of the spiral extrusion section (3); the interval connecting insulation section (5) is respectively provided on the outside of the spiral extrusion section (3) and between the multi-stage temperature control section (4). The multi-stage temperature control section (4) can effectively control the temperature of the corresponding working interval through sensors, heating units and cooling units, corresponding to the temperature of different intervals.

2. The multi-stage temperature-controlled extrusion equipment and method for PVC film according to claim 1, characterized in that: The spiral extrusion section (3) specifically includes: An extrusion cylinder (312) is disposed on top of a support base plate (1); The drive motor (311) is fixedly installed on the outer wall of one end of the extrusion cylinder (312); The feed hopper (3113) is connected to the outer wall of the extrusion cylinder (312).

3. The multi-stage temperature-controlled extrusion equipment and method for PVC film according to claim 2, characterized in that: The extrusion cylinder (312) is provided with a feeding preheating zone (315), a compression heating zone (316), a plasticizing uniform temperature zone (317), a melt pressure stabilizing zone (318), an outlet transition zone (319), and a die head adaptation zone (3111). The output end of the drive motor (311) is fixedly connected to a rotating extrusion rod (313). The outer wall of the rotating extrusion rod (313) is fixedly fitted with a spiral extrusion blade (314). A melt temperature sensor (3112) is provided on the outside of the die head adaptation zone (3111).

4. The multi-stage temperature-controlled extrusion equipment and method for PVC film according to claim 1, characterized in that: The multi-stage temperature control unit (4) specifically includes: The connecting block (411) is circumferentially and equidistantly fixed on the outer wall of the extrusion cylinder (312); Temperature sensor 1 (412) is disposed between connecting blocks (411); The heating plate (413) is fixedly installed on the outer wall of the extrusion cylinder (312) at equal intervals around its circumference.

5. The multi-stage temperature-controlled extrusion equipment and method for PVC film according to claim 4, characterized in that: The sensing end of the temperature sensor (412) moves through the outer wall of the extrusion cylinder (312) and extends into the interior of the extrusion cylinder (312). A cooling sleeve (414) is fixedly connected to the outer wall of the connecting block (411) away from the extrusion cylinder (312). The cooling sleeve (414) is sleeved on the outer wall of the heating plate (413).

6. The multi-stage temperature-controlled extrusion equipment and method for PVC film according to claim 5, characterized in that: A second temperature sensor (415) is fixedly installed on the outer wall of the cooling sleeve (414). A spiral cooling pipe (416) is provided inside the cooling sleeve (414). The two ends of the spiral cooling pipe (416) respectively movably penetrate the inner wall of the cooling sleeve (414) and extend to the outer wall of the cooling sleeve (414). The two ends of the spiral cooling pipe (416) are respectively connected to an input bend (417) and an output bend (418).

7. The multi-stage temperature-controlled extrusion equipment and method for PVC film according to claim 1, characterized in that: The inter-section connecting insulation part (5) specifically includes: The heat insulation sleeve (511) is fixedly sleeved on the outer wall of the extrusion cylinder (312); Support legs (512) are symmetrically fixedly installed on the outer wall of the insulation sleeve (511). Slow-flow baffles (515) are symmetrically arranged on the inner wall of the insulation sleeve (511). Slow-flow holes are equidistantly opened on the circumference of each slow-flow baffle (515). The interior of the insulation sleeve (511) is provided with a liquid inlet cavity (516), a slow-flow cavity (517), and a liquid outlet cavity (518). An input pipe (514) and an output pipe (513) are respectively connected to the outer walls on both sides of the insulation sleeve (511). The input pipe (514) is connected to the liquid inlet cavity (516), and the output pipe (513) is connected to the liquid outlet cavity (518).

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