An extruder with a gradually varying orifice spacing for plastic modification

Abstract

This invention discloses an extruder with a gradually varying orifice pitch for plastic modification, relating to the field of extruder technology. The extruder includes a main body; the main body includes a barrel, a die head communicating with the barrel, and a die communicating with the die head; the die includes a connecting part connected to the die head and multiple working parts movably sealed to the connecting part; the connecting part has a discharge port. This extruder, through a drive mechanism, rotates a rotating disk and a U-shaped plate, enabling rapid switching between multiple working parts with different gradually varying orifice pitches. It can adapt to the extrusion requirements of modified plastics of different viscosities, solving the problems of poor adaptability and cumbersome replacement of fixed gradually varying orifice pitch dies. Simultaneously, a moving mechanism drives the top column to adjust the clamping force, ensuring reliable sealing under high temperature and high pressure. It is suitable for multi-variety, small-batch production scenarios in plastic modification granulation.

Description

Technical Field

[0001] This invention relates to the field of extruder technology, specifically to an extruder with a gradually varying orifice spacing for plastic modification. Background Technology

[0002] In the field of plastic modification and processing, fillers, glass fibers, flame retardants, toughening agents, and other components are typically added to base materials such as polypropylene, polyethylene, nylon, and polycarbonate to obtain modified plastics with superior properties such as strength, heat resistance, and flame retardancy, meeting the needs of industries such as automotive, home appliances, and electronics. Extrusion granulation is the core process of plastic modification. After the material is melted and plasticized in the extruder barrel, it is extruded through the die head and die to form the final product, which is then cooled and granulated. As a key component of extrusion granulation, the arrangement of its discharge orifices directly affects the extrusion stability and particle quality. Due to the significant differences in the composition, viscosity, and flowability of modified materials, uneven flow rates can easily occur in the die channel during extrusion, with faster flow rates in the middle and slower flow rates at both ends. This leads to problems such as inconsistent strip thickness, strip breakage, and melt fracture, affecting granulation quality and production efficiency. In existing technologies, a gradually increasing orifice spacing die is usually used to balance the discharge flow rate. That is, along the width of the die, the spacing between the discharge orifices gradually increases from the middle to both ends to compensate for pressure and flow losses at both ends of the channel. Summary of the Invention

[0003] However, existing extruders with gradient orifice spacing for plastic modification mostly use fixed, integrated dies. A single die can only accommodate a single formulation or a modified material of a specific viscosity, failing to meet the process requirements of different types of modified plastics, such as high-filler, glass fiber reinforced, and thermosensitive degradable plastics, thus affecting extrusion quality. When producing different modified plastics, the entire die must be replaced, resulting in cumbersome disassembly and assembly, and long downtime. This makes it difficult to meet the production needs of multi-variety, small-batch, and rapid changeover in plastic modification, impacting production efficiency and quality.

[0004] The purpose of this invention is to provide an extruder with a gradually varying orifice pitch for plastic modification that can rotate and switch between multiple working sections with different gradually varying orifice pitches, in order to solve the problem mentioned in the background art that a fixed gradually varying orifice pitch die cannot be adapted to modified materials of different viscosities and is inconvenient to replace.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an extruder with a gradually varying orifice spacing for plastic modification, comprising a main body; the main body includes a barrel, a die head communicating with the barrel, and a die communicating with the die head; the die includes a connecting part connected to the die head and multiple working parts movably sealed to the connecting part; the connecting part has a discharge port; the working parts have discharge holes with a gradually varying orifice spacing; the main body further includes a switching and mounting mechanism for rotating and switching the working parts; the switching and mounting mechanism includes a rotating disk, a U-shaped plate connected to the rotating disk, and a drive mechanism for driving the rotating disk to rotate; The switching installation mechanism further includes an installation component for installing the working part; the installation component includes an installation frame and a first spring telescopic rod connected between the installation frame and the U-shaped plate; the working part is detachably connected to the installation frame; the main body of the device also includes a positioning pin connected to the machine head and a positioning ring connected to the working part; the main body of the device also includes a clamping mechanism for pressing the working part. The clamping mechanism includes a circular hole opened on the side wall of the U-shaped plate, a top column that can be inserted into the circular hole, and a moving mechanism that drives the top column to move; the mounting surface of the working part and the mounting surface of the connecting part are tightly fitted to form a metal hard seal, and the gradient hole spacing parameters of different working parts are different.

[0006] Preferably, the driving mechanism includes a first fixed frame, a motor connected to the first fixed frame, and a rotating shaft connected between the motor and the rotating disk; the moving mechanism includes a second fixed frame, a moving frame connected to the top column, and a T-shaped guide rod connected between the moving frame and the second fixed frame; the T-shaped guide rod passes through the second fixed frame; the moving mechanism further includes a first fixed tube connected to the second fixed frame, a first moving rod connected between the first fixed tube and the moving frame, and a first pushing assembly for moving the first moving rod; the first moving rod is slidably connected inside the first fixed tube.

[0007] Preferably, the first pushing component includes a liquid storage tank connected to the first fixed pipe, a squeezing plate slidably connected in the liquid storage tank, and a lifting component for driving the squeezing plate to move up and down; the liquid storage tank is filled with hydraulic oil.

[0008] Preferably, the lifting assembly includes a lifting plate, a lifting module connected between the lifting plate and the second fixed frame, and a second spring telescopic rod connected between the lifting plate and the pressing plate; the lifting assembly also includes a distance sensor connected to the lifting plate.

[0009] Preferably, the main body of the device further includes a first removal mechanism for removing material from the discharge hole of the working part; the first removal mechanism includes a first moving plate, a plurality of push rods and a third spring telescopic rod connected between the push rods and the first moving plate; the first removal mechanism further includes a first moving component for moving the first moving plate.

[0010] Preferably, the first moving component includes a second moving plate and a fourth spring telescopic rod connected between the second moving plate and the first moving plate; the first moving component further includes a third fixed frame connected to the first fixed frame, a fifth spring telescopic rod connected between the second moving plate and the third fixed frame, and a second pushing component for moving the second moving plate; the second pushing component includes a second fixed tube connected to the first fixed frame, a second moving rod connected between the second fixed tube and the second moving plate, and a connecting tube connecting the second fixed tube and the first fixed tube; the second moving rod is slidably connected inside the second fixed tube.

[0011] Preferably, the main body of the device further includes a second removal mechanism for removing material from the melt contact surface of the working part; the second removal mechanism includes a scraper, an inclined plate connected to the scraper, and a second moving component for driving the scraper to move; the second removal mechanism also includes a collection box disposed below the scraper.

[0012] Preferably, the second moving component includes a connecting frame connected to the first fixed frame, a sixth spring telescopic rod connected between the scraper and the connecting frame, and a third pushing component for pushing the scraper to move; the collection box is fixed to the side wall of the connecting frame.

[0013] Preferably, the third pushing component includes a rubber wheel, a first connecting block connected to the first moving plate, and a rotating rod connected between the rubber wheel and the first connecting block; the third pushing component also includes a driving component for driving the rotating rod to rotate.

[0014] Preferably, the drive assembly includes a ball screw connected to the rotating rod, a ball nut cooperating with the ball screw, and a second connecting block connected between the ball nut and the second moving plate.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This type of extruder for plastic modification, featuring a gradually changing orifice pitch, achieves rapid switching between multiple working sections with different gradually changing orifice pitches by setting up a switching installation mechanism and driving the rotating disk and U-shaped plate through a drive mechanism. It can adapt to the extrusion requirements of modified plastics with different viscosities, solving the problems of poor adaptability and cumbersome replacement of fixed gradually changing orifice pitch dies. At the same time, the moving mechanism drives the top column to adjust the clamping force, ensuring sealing reliability under high temperature and high pressure. It is suitable for multi-variety, small-batch production scenarios of plastic modification granulation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall structure from another perspective of the present invention; Figure 3 This is a schematic diagram showing the positions of the switching installation mechanism and the first removal mechanism in this invention; Figure 4 This is a schematic diagram of the die and U-shaped plate in this invention; Figure 5 This is a schematic diagram of the clamping mechanism in this invention; Figure 6 This is a schematic diagram of the switching installation mechanism in this invention; Figure 7 This is a schematic diagram of the structure of the first removal mechanism in this invention; Figure 8 This is a structural schematic diagram of the installation mechanism from another perspective in this invention; Figure 9 This is a schematic diagram of the structure of the second removal mechanism in this invention; Figure 10 This is a schematic diagram of the positioning pin and positioning ring in this invention.

[0017] In the diagram: 101, barrel; 102, head; 103, discharge port; 104, working section; 105, connecting section; 201, storage tank; 202, lifting module; 203, lifting plate; 204, extrusion plate; 301, second spring telescopic rod; 302, distance sensor; 401, first fixed frame; 402, motor; 501, second fixed pipe; 502, third fixed frame; 503, fifth spring telescopic rod; 504, second moving rod; 505, connecting pipe; 601, scraper; 602, inclined plate; 603, collection box; 701, first connecting block; 702, rotating rod; 703, rubber wheel; 801, connecting frame; 8 02. Sixth spring telescopic rod; 901. Ball screw; 902. Ball nut; 903. Second connecting block; 1001. Second moving plate; 1002. Fourth spring telescopic rod; 1003. First moving plate; 1004. Third spring telescopic rod; 1005. Top rod; 1101. Rotating disk; 1102. U-shaped plate; 1103. First spring telescopic rod; 1104. Mounting frame; 1105. Positioning pin; 1106. Positioning ring; 1201. Second fixing frame; 1202. First fixing tube; 1203. First moving rod; 1204. Moving frame; 1205. Top column; 1206. Round hole; 1207. T-shaped guide rod. Detailed Implementation

[0018] 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.

[0019] Please see Figures 1-10 This invention provides an extruder with a gradually varying orifice spacing for plastic modification, comprising a main body. The main body includes a barrel 101, a die head 102 communicating with the barrel 101, and a die communicating with the die head 102. Other components of the extruder are known in this technical field and will not be described in detail here. The die includes a connecting part 105 connected to the die head 102 and a plurality of working parts 104 movably sealed to the connecting part 105. A discharge port 103 is provided on the connecting part 105. The working parts 104 are provided with discharge holes with a gradually varying orifice spacing. The main body also includes a switching and mounting mechanism for rotating and switching the working parts 104. The switching and mounting mechanism includes a rotating disk 1101, a U-shaped plate 1102 connected to the rotating disk 1101, and a drive mechanism for driving the rotating disk 1101 to rotate. The switching installation mechanism also includes an installation assembly for installing the working part 104; the installation assembly includes a mounting frame 1104 and a first spring telescopic rod 1103 connected between the mounting frame 1104 and the U-shaped plate 1102; the working part 104 is detachably connected to the mounting frame 1104; the main body of the device also includes a positioning pin 1105 connected to the machine head 102 and a positioning ring 1106 connected to the working part 104; the main body of the device also includes a clamping mechanism for clamping the working part 104; The clamping mechanism includes a circular hole 1206 formed in the side wall of the U-shaped plate 1102, a top column 1205 that can be inserted into the circular hole 1206, and a moving mechanism for driving the top column 1205 to move. The mounting surface of the working part 104 and the mounting surface of the connecting part 105 are tightly fitted to form a metal hard seal. The gradient hole spacing parameters of different working parts 104 are different. Different modified materials have very large differences in flowability. Ordinary PP / PE: good flowability, small gradient hole spacing is used; high-filled PP with calcium powder has poor flowability, medium gradient hole spacing is used; glass fiber reinforced PA / PC has poor flowability. The material has poor stability and requires a large gradient die spacing. It is also suitable for degradable PLA / PBAT, which is prone to breakage. A special gradient die spacing is used. The drive mechanism drives the rotating disk 1101 and U-shaped plate 1102 to rotate, enabling rapid switching of multiple sets of working parts 104 with different gradient die spacings. This can adapt to the extrusion requirements of modified plastics with different viscosities and solves the problems of poor adaptability and cumbersome replacement of fixed gradient die spacing. At the same time, the moving mechanism drives the top column 1205 to adjust the clamping force, ensuring the sealing reliability under high temperature and high pressure. It is suitable for multi-variety, small-batch production scenarios of plastic modification granulation.

[0020] The driving mechanism includes a first fixed frame 401, a motor 402 connected to the first fixed frame 401, and a rotating shaft connecting the motor 402 and the rotating disk 1101. During switching, the motor 402 is started, and its rotation drives the rotating disk 1101 to rotate via the rotating shaft. This rotation, in turn, drives the working part 104 to rotate via the U-shaped plate 1102, the first spring telescopic rod 1103, and the mounting frame 1104. Rotation stops when the working part 104 is aligned with the discharge port 103. The rotation angle is controlled by the motor 402, making switching the working part 104 more convenient and faster. The moving mechanism includes a second fixed frame 1201, a moving frame 1204 connected to the top column 1205, and a T-shaped guide rod 1207 connecting the moving frame 1204 and the second fixed frame 1201. The T-shaped guide rod 1207 passes through the second fixed frame 1201. The moving mechanism also includes a first fixed pipe 1202 connected to the second fixed frame 1201. A first moving rod 1203 and a first pushing assembly are connected between the first fixed tube 1202 and the moving frame 1204. The first moving rod 1203 is slidably connected inside the first fixed tube 1202. The first pushing assembly pushes the first moving rod 1203 to move. At the same time, the moving frame 1204 drives the top column 1205 to move, so that the top column 1205 passes through the round hole 1206 and abuts against the side wall of the mounting frame 1104, thereby pushing the working part 104 to move, so that the working part 104 abuts and seals against the connecting part 105. At the same time, the positioning pin 1105 is inserted into the positioning ring 1106 for limiting, and the discharge hole is connected to the discharge port 103. This not only facilitates the pressing and limiting of the working part 104, but also ensures the sealing reliability under high temperature and high pressure. When switching, the pressing mechanism is released, so that the working part 104 is disengaged from the connecting part 105, which can avoid wear during switching.

[0021] The first pushing assembly includes a liquid storage tank 201 connected to the first fixed pipe 1202, a pressing plate 204 slidably connected within the liquid storage tank 201, and a lifting assembly for driving the pressing plate 204 to move up and down. The liquid storage tank 201 is filled with hydraulic oil. By driving the pressing plate 204 downward along the liquid storage tank 201 through the lifting assembly, the hydraulic oil can be squeezed, allowing the hydraulic oil to enter the first fixed pipe 1202. Under the action of hydraulic pressure, the first moving rod 1203 can be moved. At the same time, the moving frame 1204 drives the top column 1205 to move, so that the top column 1205 passes through the circular hole 1206 and is connected to the mounting frame 11. The side walls of 04 abut against each other. By controlling the downward stroke and pressure of the extrusion plate 204, the output pressure of the hydraulic oil can be precisely adjusted, realizing stepless adjustment of the clamping force of the top column 1205. This adapts to the sealing requirements of modified materials with different viscosities. The lower the viscosity of the modified plastic, the lower the required extrusion force. While ensuring reliable high-temperature and high-pressure sealing, it avoids wear and deformation of the working part 104 caused by overpressure. Compared with traditional bolt tightening, this hydraulic drive structure has a uniform and stable clamping force and is easy to adjust. It can effectively avoid the leakage problem caused by the preload decay, and at the same time greatly improve the switching efficiency of the working part 104, meeting the high-efficiency production needs of multiple varieties and small batches of modified plastics.

[0022] The lifting assembly includes a lifting plate 203, a lifting module 202 connected between the lifting plate 203 and the second fixed frame 1201, and a second spring telescopic rod 301 connected between the lifting plate 203 and the extrusion plate 204. The lifting assembly also includes a distance sensor 302 connected to the lifting plate 203. The lifting module 202 drives the lifting plate 203 to rise and fall, and the second spring telescopic rod 301 drives the extrusion plate 204 to press down. The second spring telescopic rod 301 buffers rigid impact and achieves flexible pressure application. The distance sensor 302 detects the compression amount of the second spring telescopic rod 301, accurately controls the hydraulic pressure, ensures that the clamping force of the top column 1205 matches the material pressure, avoids material leakage and deformation, and improves the control accuracy and stability of the system.

[0023] The main body of the device also includes a first removal mechanism for removing material from the discharge hole of the working section 104; the first removal mechanism includes a first moving plate 1003, a plurality of push rods 1005, and a third spring telescopic rod 1004 connected between the push rods 1005 and the first moving plate 1003; the first removal mechanism also includes a first moving component for moving the first moving plate 1003, the first moving component driving the first moving plate 1003 to move, thereby driving the plurality of push rods 1005 to move through the third spring telescopic rod 1004, and the push rods 1005 aligned with the discharge hole can be inserted into the discharge hole. The material remaining in the discharge hole is removed and sealed, while the other push rods 1005 abut against the side wall of the working part 104, compressing the third spring telescopic rod 1004. By setting multiple push rods 1005 and the third spring telescopic rod 1004, each working part 104 can be used, ensuring that all discharge holes of each working part 104 are inserted with push rods 1005, which can automatically complete the hole cleaning, avoid cross-contamination of materials, improve material changing efficiency and production cleanliness. When not removed, there is a distance between the push rods 1005 and the U-shaped plate 1102, ensuring that the U-shaped plate 1102 will not interfere when rotating.

[0024] The first moving assembly includes a second moving plate 1001 and a fourth spring telescopic rod 1002 connected between the second moving plate 1001 and the first moving plate 1003; the first moving assembly also includes a third fixed frame 502 connected to the first fixed frame 401, a fifth spring telescopic rod 503 connected between the second moving plate 1001 and the third fixed frame 502, and a second pushing assembly for moving the second moving plate 1001; the second pushing assembly includes a second fixed tube 501 connected to the first fixed frame 401, a second moving rod 504 connected between the second fixed tube 501 and the second moving plate 1001, and a connecting tube 505 connecting the second fixed tube 501 and the first fixed tube 1002; the second moving rod 504 is slidably connected... Connected to the second fixed pipe 501, when hydraulic oil is introduced into the first fixed pipe 1202, the hydraulic oil is simultaneously injected into the second fixed pipe 501 through the connecting pipe 505, pushing the second moving rod 504 to extend outward, thereby driving the second moving plate 1001 to move away from the first fixed frame 401. The fifth spring telescopic rod 503 is stretched, and at the same time, the first moving plate 1003 is driven to move through the fourth spring telescopic rod 1002. The hole cleaning operation and the clamping mechanism are driven synchronously through hydraulic linkage. No additional power source is required. The hole cleaning operation is automatically completed while the working part 104 is clamped, which greatly improves the material changing efficiency and solves the industry pain point of traditional hole cleaning requiring manual operation and low efficiency. It is suitable for the automated production needs of various modified plastics.

[0025] The main body of the device also includes a second removal mechanism for removing material from the melt contact surface of the working section 104; the second removal mechanism includes a scraper 601, an inclined plate 602 connected to the scraper 601, and a second moving component for driving the scraper 601 to move; the second removal mechanism also includes a collection box 603 disposed below the scraper 601, and the second moving component drives the scraper 601 to scrape along the melt contact surface of the working section 104 to completely remove the material residue remaining on the contact surface, avoiding the accumulation and cross-contamination of different batches of modified materials on the contact surface, and ensuring the smooth operation of the working section 104. 4. The sealing and fitting accuracy of the connection part 105; the inclined plate 602 can guide the scraped material into the collection box 603 to realize the centralized collection and cleaning of residual materials, and prevent the scraped material from falling into the equipment and causing jamming and pollution; this mechanism can automatically complete the material cleaning operation of the contact surface during the switching of the working part 104, without the need for manual disassembly and wiping, which greatly improves the material changing efficiency and sealing reliability, solves the industry pain points of difficult cleaning of residual materials on the contact surface of traditional die, which easily leads to sealing failure and product pollution, and meets the clean production and stable sealing requirements of multiple varieties and small batches of plastic modification.

[0026] The second moving component includes a connecting frame 801 connected to the first fixed frame 401, a sixth spring telescopic rod 802 connected between the scraper 601 and the connecting frame 801, and a third pushing component for moving the scraper 601. The collection box 603 is fixed to the side wall of the connecting frame 801. After the push rod 1005 is inserted into the discharge hole, it can remove and seal the residual material inside. The scraper 601 can be pushed along the melt contact surface of the working part 104 by the third pushing component. Under the action of the scraper 601 and the inclined plate 602, the residual material on the melt contact surface can be scraped and cleaned, and the material falls into the collection box 603 for collection, which is more convenient and faster. In addition, it can prevent the material from re-entering the discharge hole during scraping, ensuring the removal effect.

[0027] The third pushing assembly includes a rubber wheel 703, a first connecting block 701 connected to the first moving plate 1003, and a rotating rod 702 connected between the rubber wheel 703 and the first connecting block 701. The third pushing assembly also includes a driving assembly for driving the rotating rod 702 to rotate. When the second moving plate 1001 and the first moving plate 1003 move synchronously, the rubber wheel 703 can be moved by the first connecting block 701 and the rotating rod 702, moving it to the bottom of the scraper 601 and abutting against it. After the top rod 1005 is inserted into the discharge hole, the first moving plate 1003 abuts against the U-shaped plate 1102. When the second moving plate 1001 continues to move, the fourth spring telescopic rod 1002 is gradually compressed. At this time, the rotating rod 702 can be driven to rotate by the driving assembly, and the rubber wheel 703 can be driven to rotate, thereby driving the scraper 601 to move away from the connecting frame 801. The sixth spring telescopic rod 802 is stretched, which facilitates the movement of the scraper 601.

[0028] The drive assembly includes a ball screw 901 connected to the rotating rod 702, a ball nut 902 cooperating with the ball screw 901, and a second connecting block 903 connecting the ball nut 902 and the second moving plate 1001. After the push rod 1005 is inserted into the discharge hole, the first moving plate 1003 abuts against the U-shaped plate 1102. When the second moving plate 1001 continues to move, the fourth spring telescopic rod 1002 is gradually compressed. At this time, the distance between the second connecting block 903 and the first connecting block 701 gradually decreases, allowing the ball nut 902 to move on the side wall of the ball screw 901, thereby driving the ball screw 901 to rotate. When the ball screw 901 rotates, it can drive the rubber wheel 703 to rotate through the rotating rod 702, without the need for an additional power source.

[0029] Working principle: During use, the raw material is fed into the barrel 101 for melting and plasticization, and then extruded through the die head 102 and the die. During extrusion, the material passes through the discharge port 103 and then through the gradually spaced discharge holes on the working part 104. The middle discharge hole has a small hole spacing, while the two end discharge holes have a large hole spacing, which solves the problem of uneven discharge and ensures the quality of extrusion. When producing different modified plastics, different gradually spaced discharge holes must be used to ensure uniform discharge due to the different fluidity. At this time, the working part 104 needs to be switched. When switching, the motor 402 is started. The rotation of the motor 402 drives the rotating disk 1101 to rotate through the rotating shaft, and drives the working part 104 to rotate through the U-shaped plate 1102, the first spring telescopic rod 1103 and the mounting frame 1104.

[0030] When the working part 104 is aligned with the discharge port 103, the lifting module 202 drives the lifting plate 203 to move downward, and the second spring telescopic rod 301 drives the extrusion plate 204 to move downward along the liquid storage tank 201, which can extrude the hydraulic oil in the liquid storage tank 201, so that the hydraulic oil enters the first fixed pipe 1202. Under the action of hydraulic pressure, the first moving rod 1203 can be moved. At the same time, the moving frame 1204 drives the top column 1205 to move, so that the top column 1205 passes through the round hole 1206 and abuts against the side wall of the mounting frame 1104, thereby pushing the working part 104 to move, so that the working part 104 abuts and seals against the connecting part 105. At the same time, the positioning pin 1105 is inserted into the positioning ring 1106 for limiting, and the discharge hole is connected to the discharge port 103, so that different working parts 104 can be switched and installed according to different modified plastics, which is more convenient and faster, and ensures the quality of extrusion.

[0031] Furthermore, the extrusion pressure between the working part 104 and the connecting part 105 can be adjusted according to the different modified plastics. When the working part 104 and the connecting part 105 abut against each other, as the lifting plate 203 continues to move downward, the second spring telescopic rod 301 is gradually compressed. By observing the distance change of the extrusion plate 204 through the distance sensor 302, the compression amount of the second spring telescopic rod 301 can be determined, thereby adjusting and controlling the extrusion pressure between the working part 104 and the connecting part 105. The lower the viscosity of the modified plastic, the lower the required extrusion pressure. While ensuring reliable high-temperature and high-pressure sealing, it avoids wear and deformation of the working part 104 caused by overpressure.

[0032] When switching installation, feeding must be stopped first to squeeze out the remaining material in the barrel 101. After emptying the raw material, add special cleaning material to flush the flow channel. Then reduce the screw speed to reduce the pressure of the die head 102 to near 0. Appropriately reduce the temperature of the die head 102 and the die to a safe range. After confirming that there is no pressure and no risk of melt ejection, loosen the clamping mechanism and switch the working part 104. The working part 104 after use is rotated to the vertical downward position, while the other working part 104 is rotated to the discharge port 103 for clamping and fixing. At the same time, when the hydraulic oil enters the first fixed pipe 1202 during clamping, it can enter the second fixed pipe 501 through the connecting pipe 505.

[0033] Under hydraulic pressure, the second moving rod 504 and the second moving plate 1001 can be moved, and the fifth spring telescopic rod 503 is stretched. When the second moving plate 1001 moves, the first moving plate 1003 can be moved by the fourth spring telescopic rod 1002, and then the third spring telescopic rod 1004 can move multiple push rods 1005. The push rod 1005 aligned with the discharge hole can be inserted into the discharge hole to remove and seal the residual material in the discharge hole. The other push rods 1005 can abut against the side wall of the working part 104, so that the third spring telescopic rod 1004 is compressed. By setting multiple push rods 1005 and the third spring telescopic rod 1004, each working part 104 can be accommodated. At the same time, the first moving plate 1003 abuts against the U-shaped plate 1102, so that it no longer moves, thereby facilitating the removal of residual material in the discharge hole, which is more convenient and faster.

[0034] When the second moving plate 1001 and the first moving plate 1003 move synchronously, the rubber wheel 703 can be moved through the first connecting block 701 and the rotating rod 702, moving it to the bottom of the scraper 601 and abutting against it. After the top rod 1005 is inserted into the discharge hole, the first moving plate 1003 abuts against the U-shaped plate 1102. When the second moving plate 1001 continues to move, the fourth spring telescopic rod 1002 is gradually compressed. At this time, the distance between the second connecting block 903 and the first connecting block 701 gradually decreases, allowing the ball nut 902 to roll... The side wall of the ball screw 901 moves, thereby driving the ball screw 901 to rotate. When the ball screw 901 rotates, it can drive the rubber wheel 703 to rotate through the rotating rod 702, and drive the scraper 601 to move away from the connecting frame 801. The sixth spring telescopic rod 802 is stretched. Under the action of the scraper 601 and the inclined plate 602, the melt contact surface of the working part 104 can be scraped and cleaned, and the melt falls into the collection box 603 for collection, which is more convenient and faster. In addition, it can prevent the material from re-entering the discharge hole during scraping, ensuring the removal effect.

Claims

1. An extruder with a gradually changing pitch for plastic modification, characterized by: The device body comprises a barrel (101), a head (102) communicated with the barrel (101), and a die communicated with the head (102); the die comprises a connecting part (105) connected with the head (102) and a plurality of working parts (104) movably sealed with the connecting part (105); the connecting part (105) is provided with a discharge port (103); the working part (104) is provided with a gradually changing hole distance discharge hole; the device body further comprises a switching installation mechanism for switching and installing the working part (104); the switching installation mechanism comprises a rotating disc (1101), a U-shaped plate (1102) connected with the rotating disc (1101), and a driving mechanism for driving the rotating disc (1101) to rotate; The switching installation mechanism further comprises an installation assembly for installing the working part (104); the installation assembly comprises an installation frame (1104) and a first spring telescopic rod (1103) connected between the installation frame (1104) and the U-shaped plate (1102); the working part (104) is detachably connected with the installation frame (1104); the device body further comprises a positioning pin (1105) connected with the head (102) and a positioning ring (1106) connected to the working part (104); the device body further comprises a pressing mechanism for pressing the working part (104); The pressing mechanism comprises a circular hole (1206) formed in the side wall of the U-shaped plate (1102), a jacking column (1205) that can be inserted into the circular hole (1206), and a moving mechanism for driving the jacking column (1205) to move; the mounting surface of the working part (104) and the mounting surface of the connecting part (105) are tightly attached to form a metal hard seal, and the gradually changing hole distance parameters of different working parts (104) are different; The moving mechanism comprises a second fixed frame (1201), a moving frame (1204) connected with the jacking column (1205), and a T-shaped guide rod (1207) connected between the moving frame (1204) and the second fixed frame (1201); the T-shaped guide rod (1207) penetrates through the second fixed frame (1201); the moving mechanism further comprises a first fixed tube (1202) connected with the second fixed frame (1201), a first moving rod (1203) connected between the first fixed tube (1202) and the moving frame (1204), and a first pushing assembly for pushing the first moving rod (1203) to move; the first moving rod (1203) is slidingly connected in the first fixed tube (1202); The first pushing assembly comprises a liquid storage tank (201) communicated with the first fixed tube (1202), an extrusion plate (204) slidingly connected in the liquid storage tank (201), and a lifting assembly for driving the extrusion plate (204) to lift and lower; the liquid storage tank (201) is filled with hydraulic oil; The lifting assembly includes a lifting plate (203), a lifting module (202) connected between the lifting plate (203) and the second fixed frame (1201), and a second spring telescopic rod (301) connected between the lifting plate (203) and the extrusion plate (204); the lifting assembly also includes a distance sensor (302) connected to the lifting plate (203).

2. The extruder with gradually changed hole pitch for plastic modification according to claim 1, characterized in that: The drive mechanism includes a first fixed frame (401), a motor (402) connected to the first fixed frame (401), and a rotating shaft connected between the motor (402) and the rotating disk (1101).

3. The extruder with gradually changed hole pitch for plastic modification according to claim 2, characterized in that: The main body of the device also includes a first removal mechanism for removing material from the discharge hole of the working part (104); the first removal mechanism includes a first moving plate (1003), a plurality of push rods (1005) and a third spring telescopic rod (1004) connected between the push rods (1005) and the first moving plate (1003); the first removal mechanism also includes a first moving component for moving the first moving plate (1003).

4. The extruder with gradually changed hole pitch for plastic modification according to claim 3, characterized in that: The first moving component includes a second moving plate (1001) and a fourth spring telescopic rod (1002) connected between the second moving plate (1001) and the first moving plate (1003); the first moving component also includes a third fixed frame (502) connected to the first fixed frame (401), a fifth spring telescopic rod (503) connected between the second moving plate (1001) and the third fixed frame (502), and a second pushing component for moving the second moving plate (1001); the second pushing component includes a second fixed tube (501) connected to the first fixed frame (401), a second moving rod (504) connected between the second fixed tube (501) and the second moving plate (1001), and a connecting tube (505) connecting the second fixed tube (501) and the first fixed tube (1202); the second moving rod (504) is slidably connected inside the second fixed tube (501).

5. The extruder with gradually changed pitch of holes for plastic modification according to claim 4, characterized in that: The main body of the device also includes a second removal mechanism for removing material from the melt contact surface of the working part (104); the second removal mechanism includes a scraper (601), an inclined plate (602) connected to the scraper (601), and a second moving component for driving the scraper (601) to move; the second removal mechanism also includes a collection box (603) disposed below the scraper (601).

6. The extruder with gradually changed pitch of holes for plastic modification according to claim 5, characterized in that: The second moving component includes a connecting frame (801) connected to the first fixed frame (401), a sixth spring telescopic rod (802) connected between the scraper (601) and the connecting frame (801), and a third pushing component for moving the scraper (601); the collection box (603) is fixed to the side wall of the connecting frame (801).

7. The extruder with gradually changing pitch of holes for plastic modification according to claim 6, characterized in that: The third pushing component includes a rubber wheel (703), a first connecting block (701) connected to the first moving plate (1003), and a rotating rod (702) connected between the rubber wheel (703) and the first connecting block (701); the third pushing component also includes a driving component for driving the rotating rod (702) to rotate.

8. The extruder with gradually changed pitch of holes for plastic modification according to claim 7, characterized in that: The drive assembly includes a ball screw (901) connected to a rotating rod (702), a ball nut (902) cooperating with the ball screw (901), and a second connecting block (903) connected between the ball nut (902) and the second moving plate (1001).

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