A twin-screw extruder with a tooth-shaped staggered stretching flow field devolatilization section

Abstract

The application relates to a double-screw extrusion device with a tooth-shaped staggered stretching flow field devolatilization section, which comprises a motor and a casing, a bushing is fixed in the casing, parallelly-arranged screw one and screw two are arranged in the bushing, the casing is sequentially divided into a feeding section, a primary devolatilization section, a secondary devolatilization section and a discharging section along the flow direction of the polymer; a group of tooth-shaped staggered stretching elements are arranged on the corresponding screw one and screw two in the primary devolatilization section; a group of star-shaped disc groups are arranged on the corresponding screw one and screw two in the secondary devolatilization section; a plurality of temperature-adjusting mixing nails are inserted into the side wall of the casing at the positions of the star-shaped disc groups in the secondary devolatilization section. The double-screw extrusion device with the tooth-shaped staggered stretching flow field devolatilization section forms a triple synergistic effect of'stretching open interface + forced surface renewal + distributed mixing enhancement', realizes stable and controllable VOC residue, increases the mixing devolatilization effect on the polymer through the temperature-adjusting mixing nails, and can also perform temperature regulation.

Description

Technical Field

[0001] This invention relates to the field of polymer processing equipment technology, specifically to a twin-screw extruder with a toothed staggered stretching flow field devouring section. Background Technology

[0002] Traditional devolatilization sections mainly use shear-type screw elements (such as kneading blocks), which generate strong shear heat, causing the material temperature to rise by 30~50℃, leading to yellowing and molecular chain degradation. Existing toothed discs are mainly used for dispersion and mixing, and their installation method (usually aligned installation) generates a flow field dominated by shear, which has limited efficiency in renewing the devolatilization interface. In view of this, we propose a twin-screw extruder with a toothed staggered stretching flow field devolatilization section. Summary of the Invention

[0003] The purpose of this invention is to provide a twin-screw extruder with a toothed staggered stretching flow field devolatilization section to solve the problems mentioned in the background art. To achieve the above objective, this invention provides the following technical solution: a twin-screw extruder with a toothed staggered stretching flow field devolatilization section, comprising a motor and a housing, a bushing fixed inside the housing, and two screws arranged in parallel inside the bushing, the motor being driven to drive the first and second screws to rotate in the same direction, the housing being divided into a feeding section, a primary devolatilization section, a secondary devolatilization section and a discharge section along the flow direction of the polymer; A set of toothed misaligned tension elements is provided on both screw one and screw two inside the first-stage devouring section, and the set of toothed misaligned tension elements is located upstream of the exhaust port of the first-stage devouring section. A set of star-shaped disks is provided on both screw one and screw two inside the secondary devouring section, and the star-shaped disks are located upstream of the exhaust port of the secondary devouring section; Multiple sets of temperature-regulating mixing nails are inserted into the side wall of the casing at the position corresponding to the star-shaped disk group on the secondary devolatilization section, and the temperature-regulating mixing nails are connected to the temperature regulation system through pipelines.

[0004] Preferably, the toothed misalignment stretching element group includes 4 to 6 toothed discs, and each toothed disc is sequentially sleeved on the corresponding screw along the axial direction. The axial misalignment angle between the toothed discs in the two sets of toothed misalignment stretching element groups is 30°. That is, the toothed disc 10 on the second screw 9 is rotated 30° around its axis and then installed and fixed. The toothed disc on the first screw is located between adjacent toothed discs on the second screw and does not interfere with each other. The end of the toothed misalignment stretching element group is provided with a reverse thread element or a sealing ring to prolong the residence time of the material.

[0005] Preferably, the toothed disk includes a threaded sleeve for being fitted onto the screw, and an integrated toothed disk coaxially fixedly connected to the threaded sleeve. The edge of the toothed disk is provided with multiple grooves at equal intervals along the circumferential direction, and teeth are formed between two adjacent grooves. The surface of the toothed disk is polished to Ra≤0.1μm, or coated with a diamond-like coating.

[0006] Preferably, the star-shaped disk assembly includes 2 to 5 star-shaped disks, and each star-shaped disk is sequentially sleeved on the corresponding screw along the axial direction. The end of the star-shaped disk assembly is provided with a reverse thread element or a sealing ring to prolong the residence time of the material. The surface of the star-shaped disk is polished to Ra≤0.1μm or coated with a diamond-like coating.

[0007] Preferably, the star-shaped disk includes a second threaded sleeve for being fitted onto the screw, and a plurality of blades are fixed on the peripheral wall of the second threaded sleeve, the plurality of blades being spirally and equally spaced along the axial direction on the peripheral wall of the second threaded sleeve.

[0008] Preferably, the blade has multiple protruding ridges fixed on the side facing the polymer flow direction, and the multiple protruding ridges are arranged in an alternating staggered manner along the radial direction of the blade. The gap between the edge of the blade and the inner wall of the bushing does not exceed 0.5 mm, and the edge of the blade is fixed with scraping ridges.

[0009] Preferably, each set of temperature-regulating mixing nails is provided with six nails. The housing and bushing are respectively provided with stepped through holes and through holes for the temperature-regulating mixing nails to pass through. The six temperature-regulating mixing nails are used to buckle and support the upper and lower sides and opposite sides of screw one and screw two, and the blades of the star-shaped disk do not interfere with the temperature-regulating mixing nails.

[0010] Preferably, the temperature-regulating mixing nail includes an outer cylinder with an inner cylinder inserted into its center. Both the inner and outer cylinders are straight cylinders. The outer cylinder is closed at both ends, with one end being a flat end wall and the other end being an inwardly recessed hemispherical end wall, forming a hemispherical cavity. A gap is left between one end of the inner cylinder and the hemispherical end wall, and the other end penetrates through the flat end wall. A cap is fitted on the exposed end of the inner cylinder. A support is provided between the inner cylinder and the inner sidewall of the outer cylinder, and the cap is connected to the temperature-regulating system through a liquid inlet pipe. The sidewall of the outer cylinder exposed to the outside of the casing is connected to the temperature-regulating system through a return pipe.

[0011] Preferably, a ball bearing is provided inside the hemispherical cavity. The ball bearing is confined within the hemispherical cavity by a matching pressure ring. The pressure ring is fixed to the hemispherical end wall by screws, and the ball bearing rolls freely within the hemispherical cavity, making rolling contact with the outer wall of the threaded sleeve.

[0012] Preferably, a ring frame is fixed in the middle of the outer side wall of the outer cylinder, and the ring frame is adapted to abut against the stepped surface of the stepped through hole. A threaded sleeve is fitted on the outer cylinder, and the outer side wall of the threaded sleeve is threadedly connected to the inner side wall of the stepped through hole. An end seal is fixed at the upper end of the threaded sleeve.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Two-stage synergistic devolatilization ensures stable and controllable VOC residues: By connecting the first-stage devolatilization stage (toothed misaligned stretching flow field) and the second-stage devolatilization stage (star-shaped disk surface renewal + mixing nail distribution), a triple synergistic effect of "stretching to open the interface + forced surface renewal + enhanced distribution mixing" is formed, achieving stable and controllable VOC residues. The toothed misaligned stretching flow field is dominated by stretching rather than shearing, and the temperature rise of the first-stage devolatilization stage is ≤10℃, which is 30~40℃ lower than that of the traditional shear-type devolatilization stage. This protects the polymer molecular structure from the source and prevents yellowing and degradation.

[0014] 2. The temperature-controlled mixing pin, while repeatedly dividing and flipping the polymer, breaking the laminar flow, and updating the interface, also supports and limits the screws 1 and 2, preventing radial displacement of the screws due to changes in internal polymer pressure, and preventing interference between the blade edge on the star disk and the inner wall of the bushing, thus playing an anti-interference protection role. In addition, the ball bearing structure reduces the friction between the mixing pin and the screw.

[0015] 3. The temperature control system delivers the temperature control medium to the inner cylinder through the liquid inlet pipe. The medium cools the ball bearings through the hemispherical end wall. At the same time, the temperature of the polymer in this section is regulated by the outer cylinder to avoid local overheating. The system can adjust the temperature in real time according to the temperature change of the polymer in this section, achieving precise low-temperature control throughout the process. The mixing nails themselves generate low temperatures. Combined with active temperature control, this ensures that the entire devolatilization process operates at low temperatures, which is especially suitable for heat-sensitive polymers such as PA, PET, PLA, and PC.

[0016] 4. The temperature-regulating mixing pin is easy to install and remove: When disassembling, the threaded sleeve is unscrewed from the stepped through hole through the end seal, and the temperature-regulating mixing pin is pulled out of the outer cylinder. There is no need to disassemble the whole machine. After removing the mixing pin, screw one and screw two can be pulled out directly, which is convenient for daily inspection and maintenance. When installing, insert the temperature-regulating mixing pin and tighten the threaded sleeve through the end seal. The operation is simple and convenient. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall assembly structure of the present invention; Figure 2 This is a schematic diagram of the arrangement of toothed disks on the two screws in the first-stage devouring section of the present invention; Figure 3 This is an axial schematic diagram of the toothed disk arrangement structure on the two screws in this invention; Figure 4This is a schematic diagram of the arrangement of star-shaped disks on the two screws in the secondary devouring section of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of the temperature-regulating mixing nail in the secondary devolatilization section of the present invention; Figure 6 This is a schematic diagram of the axial structure of the star-shaped disk in this invention; Figure 7 This is a schematic diagram of the cross-sectional structure of the temperature-regulating hybrid nail in this invention; Figure 8 for Figure 7 Enlarged structural diagram at point B in the diagram; Figure 9 for Figure 5 A magnified structural diagram at point A in the diagram.

[0018] In the diagram: 1. Motor; 2. Feeding section; 3. First-stage devolatilization section; 4. Second-stage devolatilization section; 5. Discharge section; 6. Housing; 7. Bushing; 8. Screw 1; 9. Screw 2; 10. Toothed disc; 11. Screw sleeve 1; 12. Toothed disc; 13. Groove; 14. Tooth; 15. Star-shaped disc; 16. Screw sleeve 2; 17. Blade; 18. Raised ridge; 19. Scraping ridge; 20. Temperature-regulating mixing nail; 21. Outer cylinder; 22. Inner cylinder; 23. Support; 24. Return pipe; 25. Cap; 26. Liquid inlet pipe; 27. Ring frame; 28. Threaded sleeve; 29. ​​End seal; 30. Ball bearing; 31. Hemispherical cavity; 32. Pressure ring; 33. Screw; 34. Stepped through hole; 35. Through hole. Detailed Implementation

[0019] 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.

[0020] Please see Figures 1 to 9 The present invention provides a technical solution: a twin-screw extruder with a toothed staggered stretching flow field devouring section, including a motor 1 and a housing 6. A bushing 7 is fixed inside the housing 6, and a first screw 8 and a second screw 9 arranged in parallel are arranged inside the bushing 7. The motor 1 is connected to the first screw 8 and the second screw 9 and drives the first screw 8 and the second screw 9 to rotate in the same direction. The housing 6 is divided into a feeding section 2, a primary devouring section 3, a secondary devouring section 4 and a discharge section 5 along the flow direction of the polymer. A set of toothed misaligned tensioning elements is provided on the screw 8 and screw 9 inside the first-stage devolatilization section 3, and the set of toothed misaligned tensioning elements is located upstream of the exhaust port of the first-stage devolatilization section 3. A set of star-shaped disks is provided on the screw 8 and screw 9 inside the secondary devolatilization section 4, and the star-shaped disks are located upstream of the exhaust port of the secondary devolatilization section 4. Multiple sets of temperature-regulating mixing nails 20 are inserted into the side wall of the casing 6 at the position corresponding to the star-shaped disk group on the secondary devolatilization section 4, and the temperature-regulating mixing nails 20 are connected to the temperature regulation system through pipelines.

[0021] In this embodiment, the toothed misaligned stretching element group includes 4 to 6 toothed discs 10, and each toothed disc 10 is sequentially sleeved on the corresponding screw along the axial direction. The axial misalignment angle between the toothed discs 10 in the two sets of toothed misaligned stretching element groups is 30°. The toothed discs 10 on the first screw 8 are located between adjacent toothed discs 10 on the second screw 9 and do not interfere with each other. The end of the toothed misaligned stretching element group is provided with a reverse thread element or a sealing ring to prolong the residence time of the material.

[0022] In this embodiment, the toothed disk 10 includes a threaded sleeve 11 for sleeved on the screw, and a toothed disk 12 integrally and coaxially fixedly connected to the threaded sleeve 11. The edge of the toothed disk 12 is provided with a plurality of grooves 13 at equal intervals along the circumferential direction, and teeth 14 are formed between two adjacent grooves 13. The surface of the toothed disk 10 is polished to Ra≤0.1μm, or coated with a diamond-like coating.

[0023] In this embodiment, the star disk assembly includes 2 to 5 star disks 15, and each star disk 15 is sequentially sleeved on the corresponding screw along the axial direction. The end of the star disk assembly is provided with a reverse thread element or a sealing ring to prolong the residence time of the material. The surface of the star disk 15 is polished to Ra≤0.1μm or coated with a diamond-like coating.

[0024] In this embodiment, the star-shaped disk 15 includes a second threaded sleeve 16 for sleeved on the screw, and a plurality of blades 17 are fixed on the peripheral wall of the second threaded sleeve 16. The plurality of blades 17 are spirally and equally spaced on the peripheral wall of the second threaded sleeve 16 along the axial direction.

[0025] In this embodiment, a plurality of protruding ribs 18 are fixed on the side of the blade 17 facing the polymer flow direction, and the plurality of protruding ribs 18 are arranged in an alternating staggered manner along the radial direction of the blade. The gap between the edge of the blade 17 and the inner wall of the bushing 7 does not exceed 0.5 mm, and scraping ribs 19 are fixed on the edge of the blade 17.

[0026] In this embodiment, each set of temperature-regulating mixing nails 20 is provided with six nails. The housing 6 and bushing 7 are respectively provided with stepped through holes 34 and through holes 35 for the temperature-regulating mixing nails 20 to pass through. The six temperature-regulating mixing nails 20 are used to buckle and support the upper and lower sides and opposite sides of the screw 1 8 and the screw 2 9, and the blade 17 of the star disk 15 does not interfere with the temperature-regulating mixing nails 20.

[0027] In this embodiment, the temperature-regulating mixing nail 20 includes an outer cylinder 21 with an inner cylinder 22 inserted into its center. Both the inner cylinder 22 and the outer cylinder 21 are straight cylinders. The outer cylinder 21 is closed at both ends, with one end being a flat end wall and the other end being an inwardly recessed hemispherical end wall, forming a hemispherical cavity 31. A gap is left between one end of the inner cylinder 22 and the hemispherical end wall, and the other end penetrates through the flat end wall. A cap 25 is fitted onto the exposed end of the inner cylinder 22. A bracket 23 is provided between the inner cylinder 22 and the inner sidewall of the outer cylinder 21, and the cap 25 is connected to the temperature-regulating system through an inlet pipe 26. The sidewall of the outer cylinder 21 exposed to the outside of the casing 6 is connected to the... The temperature control system is connected. A ball bearing 30 is provided in the hemispherical cavity 31. The ball bearing 30 is restricted in the hemispherical cavity 31 by a matching pressure ring 32. The pressure ring 32 is fixed to the hemispherical end wall by screws 33. The ball bearing 30 rolls freely in the hemispherical cavity 31. The ball bearing 30 rolls in contact with the outer wall of the threaded sleeve 16. A ring frame 27 is fixed in the middle of the outer wall of the outer cylinder 21. The ring frame 27 is matched to the stepped surface of the stepped through hole 34. A threaded sleeve 28 is sleeved on the outer cylinder 21. The outer wall of the threaded sleeve 28 is connected to the inner wall of the stepped through hole 34 by threads. An end seal 29 is fixed at the upper end of the threaded sleeve 28.

[0028] Working principle and advantages of this invention: The working process of this twin-screw extruder with a toothed staggered stretching flow field devouring section is as follows: like Figures 1 to 9As shown, when the entire device is started, motor 1 drives screws 8 and 2 to rotate in the same direction. In the feeding section 2, the polymer is conveyed forward while being melted and sheared. When the polymer enters the two sets of toothed staggered stretching elements in the first-stage devolatilization section 3, the tooth tips and grooves of the toothed disks 10 in the two sets of toothed staggered stretching elements form periodic convergent and expanding flow channels. The polymer undergoes an alternating stretching-relaxation process, thereby generating a flow field dominated by stretching. This is beneficial for opening the gas-liquid interface, promoting bubble nucleation and removal. Furthermore, the toothed staggered stretching flow field keeps the temperature rise of the first-stage devolatilization section 3 ≤10℃, which is 30~40℃ lower than that of the traditional shear-type devolatilization section, thus eliminating yellowing and degradation at the source. As the polymer flows, it undergoes rapid and efficient devolatilization when it passes through the exhaust port in the first-stage devolatilization section 3 under reduced pressure. When the polymer enters the second-stage devolatilization section... In stage 4, screws 8 and 9 drive two sets of star disks to mix and convey the polymer forward. The gap between the edge of blade 17 and the inner wall of bushing 7 is no more than 0.5 mm. The edge of blade 17 is fixed with scraping ridges 19, which allows blade 17 to scrape away the melt adhering to the inner wall of bushing 7 in real time and form a fresh thin layer. The protruding ridges 18 on blade 17 divert and remix the polymer. During the flow of the polymer, it is subjected to the action of temperature-regulating mixing nails 20, which makes the polymer repeatedly divided, turned, and recombined, enhancing the distribution mixing, breaking the laminar shear flow field, promoting the renewal of the gas-liquid interface, which is beneficial to devolatilization, and generating low temperature. When the material is depressurized and passes through the exhaust port of the secondary devolatilization stage 4, it undergoes efficient devolatilization. By setting two devolatilization stages and using the synergistic effect of toothed staggered stretching element group and star disk group, a synergistic effect of "stretching open interface + forced surface renewal" is formed, which effectively controls VOC residue.

[0029] As described above, each set of temperature-regulating mixing nails 20 provides support and limit for screws 8 and 9, preventing radial displacement of screws 8 and 9 due to changes in internal polymer pressure, and preventing interference between the edge of the blade 17 on the star-shaped disk 15 and the inner wall of the bushing 7. The ball bearings 30 reduce friction. When a stable change in the polymer in this section is detected, the temperature-regulating system delivers a temperature-regulating medium to the inner cylinder 22 through the liquid inlet pipe 26. This temperature-regulating medium cools the ball bearings 30 through the hemispherical end wall and regulates the temperature of the polymer at this location through the outer cylinder 21 to prevent local overheating.

[0030] When disassembling the temperature-regulating mixing nail 20, first unscrew the threaded sleeve 28 from the stepped through hole 34 through the end seal 29, and then pull out the outer cylinder 21. The operation is simple and convenient. Then, easily pull out the screw 1 8 and screw 2 9. When installing, first install screw 1 8 and screw 2 9, then insert the temperature-regulating mixing nail 20 into the corresponding stepped through hole 34 and through hole 35, and tighten the threaded sleeve 28 in the stepped through hole 34 through the end seal 29. The disassembly and assembly are convenient and quick.

[0031] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0032] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

Claims

1. A twin-screw extruder with a toothed staggered stretching flow field devouring section, comprising a motor (1) and a housing (6), wherein a bushing (7) is fixed inside the housing (6), and a first screw (8) and a second screw (9) arranged in parallel are disposed inside the bushing (7), the motor (1) is connected to the first screw (8) and the second screw (9) for transmission, and drives the first screw (8) and the second screw (9) to rotate in the same direction, characterized in that: The casing (6) is divided into a feeding section (2), a primary devolatilization section (3), a secondary devolatilization section (4) and a discharge section (5) along the flow direction of the polymer. A set of toothed misaligned tension elements is provided on the screw one (8) and screw two (9) inside the first-stage devouring section (3), and the set of toothed misaligned tension elements is located upstream of the exhaust port of the first-stage devouring section (3). A set of star-shaped disks is provided on the screws 1 (8) and 2 (9) inside the secondary devolatilization section (4), and the star-shaped disks are located upstream of the exhaust port of the secondary devolatilization section (4). Multiple sets of temperature-regulating mixing nails (20) are inserted into the side wall of the casing (6) corresponding to the position of the star-shaped disk group on the secondary devolatilization section (4), and the temperature-regulating mixing nails (20) are connected to the temperature regulation system through pipelines; The toothed misaligned stretching element group includes 4 to 6 toothed discs (10), and each toothed disc (10) is sequentially sleeved on the corresponding screw along the axial direction. The axial misalignment angle between the toothed discs (10) in the two sets of toothed misaligned stretching element groups is 30°. The toothed discs (10) on the first screw (8) are located between adjacent toothed discs (10) on the second screw (9) and do not interfere with each other. The end of the toothed misaligned stretching element group is provided with a reverse thread element or a sealing ring to prolong the residence time of the material. The toothed disk (10) includes a threaded sleeve (11) for sleeved on the screw, and a toothed disk (12) integrally and coaxially fixedly connected to the threaded sleeve (11). The edge of the toothed disk (12) is provided with a plurality of grooves (13) at equal intervals along the circumferential direction, and teeth (14) are formed between two adjacent grooves (13). The surface of the toothed disk (10) is polished to Ra≤0.1μm, or coated with a diamond-like coating.

2. The twin-screw extruder with a toothed staggered stretching flow field devouring section according to claim 1, characterized in that: The star disk assembly includes 2 to 5 star disks (15), and each star disk (15) is sequentially sleeved on the corresponding screw along the axial direction. The end of the star disk assembly is provided with a reverse thread element or a sealing ring to prolong the residence time of the material. The surface of the star disk (15) is polished to Ra≤0.1μm or coated with a diamond-like coating.

3. The twin-screw extruder with a toothed staggered stretching flow field devouring section according to claim 2, characterized in that: The star-shaped disk (15) includes a screw sleeve (16) for sleeved on the screw, and a plurality of blades (17) are fixed on the peripheral wall of the screw sleeve (16). The plurality of blades (17) are spirally and equally spaced on the peripheral wall of the screw sleeve (16) along the axial direction.

4. A twin-screw extruder with a toothed staggered stretching flow field devouring section according to claim 3, characterized in that: The blade (17) has a plurality of protruding ridges (18) fixed on the side facing the polymer flow direction, and the plurality of protruding ridges (18) are arranged in an alternating staggered manner along the radial direction of the blade. The gap between the edge of the blade (17) and the inner wall of the bushing (7) does not exceed 0.5 mm. The edge of the blade (17) is fixed with scraping ridges (19).

5. A twin-screw extruder with a toothed staggered stretching flow field devouring section according to claim 4, characterized in that: Each set of temperature-regulating mixing nails (20) is provided with six. The housing (6) and bushing (7) are respectively provided with stepped through holes (34) and through holes (35) for the temperature-regulating mixing nails (20) to pass through. The six temperature-regulating mixing nails (20) are used to buckle and support the upper and lower sides and opposite sides of screw one (8) and screw two (9), and the blade (17) of the star disk (15) does not interfere with the temperature-regulating mixing nails (20).

6. A twin-screw extruder with a toothed staggered stretching flow field devouring section according to claim 5, characterized in that: The temperature-regulating mixing nail (20) includes an outer cylinder (21) with an inner cylinder (22) inserted into its center. Both the inner cylinder (22) and the outer cylinder (21) are straight cylinders. The outer cylinder (21) is closed at both ends, with one end being a flat end wall and the other end being a hemispherical end wall that is concave inward. The hemispherical end wall forms a hemispherical cavity (31). There is a gap between one end of the inner cylinder (22) and the hemispherical end wall, and the other end penetrates through the flat end wall. A cap (25) is fitted on the exposed end of the inner cylinder (22). A bracket (23) is provided between the inner cylinder (22) and the inner side wall of the outer cylinder (21). The cap (25) is connected to the temperature regulation system through the liquid inlet pipe (26). The side wall of the outer cylinder (21) exposed to the outside of the casing (6) is connected to the temperature regulation system through the return pipe (24).

7. A twin-screw extruder with a toothed staggered stretching flow field devouring section according to claim 6, characterized in that: A ball (30) is provided in the hemispherical cavity (31). The ball (30) is restricted in the hemispherical cavity (31) by a matching pressure ring (32). The pressure ring (32) is fixed on the hemispherical end wall by a screw (33). The ball (30) rolls freely in the hemispherical cavity (31). The ball (30) rolls in contact with the outer wall of the threaded sleeve (16).

8. A twin-screw extruder with a toothed staggered stretching flow field devouring section according to claim 7, characterized in that: A ring frame (27) is fixed in the middle of the outer wall of the outer cylinder (21), and the ring frame (27) is adapted to abut against the stepped surface of the stepped through hole (34). A threaded sleeve (28) is sleeved on the outer cylinder (21), and the outer wall of the threaded sleeve (28) is connected to the inner wall of the stepped through hole (34) by thread. An end seal (29) is fixed at the upper end of the threaded sleeve (28).

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