Threaded rod for double-screw extruder and double-screw extruder
By optimizing the design of the screw rod and the division of functional areas, the problem of unstable material mixing and plasticization in twin-screw extruders was solved, improving mixing efficiency and heat transfer performance, and ensuring product quality stability and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANXI YIZE PAINT CO LTD
- Filing Date
- 2025-06-12
- Publication Date
- 2026-05-22
AI Technical Summary
The existing twin-screw extruders use a single-structure design for the screw, which leads to unstable material mixing and plasticizing quality, affecting production efficiency and product quality.
By optimizing the spacing, depth, and direction of the threaded rods, different functional areas are formed on the surface of the screw. Combined with the cooperation of the conveying cylinder, inner cavity, first conveying screw, and second conveying screw, the material can be optimized for multiple stages, including raw material conveying, mixing and preheating, melting and plasticizing, and pressurized extrusion.
It significantly improves the mixing efficiency and heat transfer performance of materials, ensures the stability of the melting effect of extruded products, and improves production efficiency and product quality.
Smart Images
Figure CN224266113U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of twin-screw extruders, specifically to a threaded rod for a twin-screw extruder and a twin-screw extruder. Background Technology
[0002] Twin-screw extruders utilize two meshing screws rotating within a barrel to convey, mix, plasticize, and extrude materials. Through the synergistic effect of the twin screws, they significantly improve material mixing efficiency, heat transfer performance, and process controllability. They are widely used in polymer materials, food, chemical, and pharmaceutical fields. However, in existing technologies, the screws used in twin-screw extruders often employ a single-thread structure design, which to some extent limits the mixing effect and plasticization quality of materials between the screws. This results in unstable melt quality of the extruded products, affecting production efficiency and product quality. Utility Model Content
[0003] To address the shortcomings of existing technologies, this utility model provides a threaded rod for a twin-screw extruder and a twin-screw extruder, solving the problem that the threaded rods used in existing twin-screw extruders often adopt a single thread structure design, which to some extent limits the mixing effect and plasticizing quality of materials between screws, resulting in unstable melt quality of extruded products and affecting production efficiency and product quality.
[0004] To achieve the above objectives, this utility model provides the following technical solution: a threaded rod for a twin-screw extruder, comprising a conveying cylinder, an inner cavity inside the conveying cylinder, a first conveying screw on one side of the inner cavity, and a second conveying screw on the side of the inner cavity away from the first conveying screw. The first and second conveying screws are meshed together. Each of the first and second conveying screws has a feeding section at one end. Each of the first and second conveying screws has a wide-spacing mixing section at the end near the feeding section. Each of the first and second conveying screws has a conical melting section on the side of the wide-spacing mixing section away from the feeding section. Each of the first and second conveying screws has a forward conveying section on the side of the conical melting section away from the wide-spacing mixing section. Each of the first and second conveying screws has a discharge straight rod section on the side of the forward conveying section away from the conical melting section. Each of the first and second conveying screws has a reverse conveying section on the side of the discharge straight rod section away from the forward conveying section.
[0005] Preferably, gearboxes are fixedly connected to both ends of the conveying cylinder. Extension shafts are provided at the end of the first conveying screw near the reverse conveying section and at both ends of the second conveying screw. A drive shaft is provided at the end of the first conveying screw away from the reverse conveying section. Sealed bearings are fixedly connected at equal intervals to the outer walls of the extension shafts and the drive shafts. The outer walls of the sealed bearings are fixedly connected to the gearboxes. Helical gears are fixedly connected to the outer walls of the extension shafts and the drive shafts inside the gearboxes. The helical gears located on the first conveying screws mesh with the helical gears located on the second conveying screws.
[0006] Preferably, the first and second conveying screws are provided with barrier end plates on the side of the feeding section away from the wide-distance mixing section.
[0007] Preferably, the outer wall of the feeding section is provided with shearing teeth at equal intervals, and the shearing teeth located on the first conveying screw are engaged with the shearing teeth located on the second conveying screw.
[0008] Preferably, the outer wall of the cone-shaped melting section near the wide-spacing mixing section is provided with venting grooves at equal intervals.
[0009] This application also provides a twin-screw extruder, including a frame, a drive assembly, a heating module, and a threaded rod for the twin-screw extruder as described above. The conveying cylinder is fixedly connected to the top of the frame, the drive assembly is drivenly connected to the first conveying screw, the outer wall of the conveying cylinder is equidistantly provided with heating modules, the conveying cylinder is connected to a discharge hopper above the feeding section, and the conveying cylinder is provided with a discharge port below the discharge straight rod section.
[0010] This utility model provides a threaded rod for a twin-screw extruder and a twin-screw extruder. It offers the following advantages: Through the coordination of the conveying cylinder, inner cavity, first conveying screw, second conveying screw, feeding section, wide-pitch mixing section, conical shaft melting section, forward conveying section, discharge straight rod section, and reverse conveying section, and by optimizing the thread pitch, thread depth, and thread direction, different functional areas can be formed on the screw surface of the twin-screw extruder. During material conveying, through optimized processing of multiple stages such as raw material conveying, mixing and preheating, melting and plasticizing, and pressurized extrusion, compared with a single-threaded conveying method, it can significantly improve the mixing efficiency and heat transfer performance of the material, thereby ensuring the stability of the extruded product's melting effect, improving the melt quality and production quality of the extruded product. This contributes to improving the production efficiency and product quality stability of the twin-screw extruder.
[0011] By optimizing the structure of the conveyor cylinder and twin screws through the cooperation between the conveyor cylinder, the first conveyor screw, the second conveyor screw, the gearbox, the extension shaft, the sealed bearing, the helical gear, and the drive shaft, and by adopting a bottom discharge method, both ends of the conveyor screw can be effectively supported and fixed. Helical gears for transmission can be installed at both ends of the conveyor screw. Compared with the end discharge method, this can effectively improve the stability and load-bearing capacity of the screw during rotation, thereby avoiding bending or deformation of the screw due to uneven force, reducing friction and wear between the conveying structures, and thus helping to extend the service life of the twin screw extruder. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the structure of this utility model;
[0013] Figure 2 This is a top view of the structure of the conveying cylinder, the first conveying screw, and the second conveying screw in this utility model;
[0014] Figure 3 This is a schematic diagram of the structure of the wide-spacing mixing section, the conical shaft melting section, and the discharge straight rod section in this utility model;
[0015] Figure 4 for Figure 2 A magnified view of a portion of region A in the middle;
[0016] Figure 5 for Figure 1 A magnified view of a portion of region B in the middle.
[0017] In the diagram: 1. Conveying cylinder; 2. Inner cavity; 3. First conveying screw; 4. Second conveying screw; 5. Feeding section; 6. Wide-gap mixing section; 7. Conical shaft melting section; 8. Forward conveying section; 9. Discharge straight rod section; 10. Reverse conveying section; 11. Gearbox; 12. Extension shaft; 13. Sealed bearing; 14. Helical gear; 15. Drive shaft; 16. Barrier end plate; 17. Shearing gear; 18. Exhaust trough; 19. Frame; 20. Drive assembly; 21. Heating module; 22. Discharge hopper; 23. Discharge port. Detailed Implementation
[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0019] In the existing technology, the screws used in twin-screw extruders often adopt a single screw structure design, which to some extent limits the mixing effect and plasticizing quality of materials between screws, resulting in unstable melt quality of extruded products and affecting production efficiency and product quality.
[0020] In view of this, the present invention provides a threaded rod for a twin-screw extruder and a twin-screw extruder. Through the coordination between the conveying cylinder, inner cavity, first conveying screw, second conveying screw, feeding section, wide-pitch mixing section, conical shaft melting section, forward conveying section, discharge straight rod section, and reverse conveying section, and through optimized design of thread pitch, thread depth, and thread direction, different functional areas are formed on the screw surface of the twin-screw extruder. During the material conveying process, through optimized processing of multiple stages such as raw material conveying, mixing and preheating, melting and plasticizing, and pressurized extrusion, compared with the conveying method of a single thread structure, the mixing efficiency and heat transfer performance of the material are significantly improved, ensuring the stability of the melting effect of the extruded product, and improving the melt quality and production quality of the extruded product.
[0021] Those skilled in the art should connect all electrical components and their compatible power supplies in this case via wires. Appropriate controllers and encoders should be selected according to the actual situation to meet control requirements. The specific connection and control sequence should refer to the working principle described below, where the electrical components are connected in sequence. The detailed connection methods are well-known in the art. The following mainly introduces the working principle and process, and will not describe the electrical control further.
[0022] Depend on Figure 1-5 It is known that a screw for a twin-screw extruder includes a conveying cylinder 1, an inner cavity 2 inside the conveying cylinder 1, a first conveying screw 3 inside one side of the inner cavity 2, and a second conveying screw 4 inside the inner cavity 2 away from the first conveying screw 3. The first conveying screw 3 and the second conveying screw 4 are meshed and connected. A feeding section 5 is provided at one end of both the first conveying screw 3 and the second conveying screw 4. A wide-spaced mixing section 6 is provided at the end of both the first conveying screw 3 and the second conveying screw 4 near the feeding section 5. Both the first conveying screw 3 and the second conveying screw 4 are provided with a conical melting section 7 on the side of the wide-spacing mixing section 6 away from the feeding section 5. Both the first conveying screw 3 and the second conveying screw 4 are provided with a forward conveying section 8 on the side of the conical melting section 7 away from the wide-spacing mixing section 6. Both the first conveying screw 3 and the second conveying screw 4 are provided with a discharge straight rod section 9 on the side of the forward conveying section 8 away from the conical melting section 7. Both the first conveying screw 3 and the second conveying screw 4 are provided with a reverse conveying section 10 on the side of the discharge straight rod section 9 away from the forward conveying section 8.
[0023] In the specific implementation process, it is worth noting that through the cooperation between the conveying cylinder 1, the inner cavity 2, the first conveying screw 3, and the second conveying screw 4, the first conveying screw 3 and the second conveying screw 4 are installed in the inner cavity 2 of the conveying cylinder 1, with opposite thread directions and mutual meshing. The outer surfaces of the threads are in close contact with the inner wall of the inner cavity 2. The first conveying screw 3 and the second conveying screw 4 rotate in opposite directions within the conveying cylinder 1. During material conveying, the mutually meshing thread structure forms a tight material conveying channel between the threads, ensuring the stability and continuity of the material during extrusion. Simultaneously, it creates strong shearing, stretching, and compression effects between the two screws, thereby improving the mixing effect and plasticizing quality of the material. Through the first conveying screw 3, the second... The coordination between the conveying screw 4, feeding section 5, wide-pitch mixing section 6, conical shaft melting section 7, forward conveying section 8, discharge straight rod section 9, and reverse conveying section 10, through optimized design of thread pitch, thread depth, and thread direction, forms the feeding section 5, wide-pitch mixing section 6, conical shaft melting section 7, forward conveying section 8, discharge straight rod section 9, and reverse conveying section 10 on the first conveying screw 3 and the second conveying screw 4. During material conveying and processing, each section has different functions and roles. The feeding section 5 is located below the feed pipe inlet or hopper. Under the action of the feeding section 5, the material is introduced into the wide-pitch mixing section 6. The wide-pitch mixing section 6, through its larger thread pitch, allows the material to undergo preliminary mixing and preheating under low conveying speed and low shear force. The conical shaft... The shaft of the melting section 7 has a tapered structure, with a slightly smaller diameter near the wide-spacing mixing section 6. This gives the tapered melting section 7 a larger material capacity at the end near the wide-spacing mixing section 6. As the material is conveyed in the tapered melting section 7, the shear and extrusion forces gradually increase, effectively promoting the melting and homogenization process and improving melting efficiency and quality. The forward conveying section 8 further conveys and compresses the material, increasing its density and uniformity. The discharge straight rod section 9, without a threaded structure, is located above the discharge pipe opening and smoothly conveys the molten and homogenized material to the extruder outlet. The reverse conveying section 10 conveys the material in the opposite direction from the forward conveying section 8 on the side of the discharge straight rod section 9, subjecting the material to two forces above the discharge pipe opening. The material is drawn into the discharge pipe located below by the extrusion force in the directional direction. Through the cooperation of the conveying cylinder 1, inner cavity 2, first conveying screw 3, second conveying screw 4, feeding section 5, wide-pitch mixing section 6, conical shaft melting section 7, forward conveying section 8, discharge straight rod section 9, and reverse conveying section 10, and through the optimized design of the thread pitch, thread depth, and thread direction, different functional areas are formed on the screw surface of the twin-screw extruder. During the material conveying process, through the optimized processing of multiple stages such as raw material conveying, mixing and preheating, melting and plasticizing, and pressurized extrusion, compared with the conveying method of a single thread structure, the mixing efficiency and heat transfer performance of the material are significantly improved, ensuring the stability of the melting effect of the extruded product, and improving the melt quality and production quality of the extruded product.
[0024] Furthermore, gearboxes 11 are fixedly connected to both ends of the conveying cylinder 1. Extension shafts 12 are provided at the end of the first conveying screw 3 near the reverse conveying section 10 and at both ends of the second conveying screw 4. A drive shaft 15 is provided at the end of the first conveying screw 3 away from the reverse conveying section 10. Sealed bearings 13 are fixedly connected at equal intervals to the outer walls of the extension shaft 12 and the drive shaft 15. The outer walls of the sealed bearings 13 are fixedly connected to the gearbox 11. Helical gears 14 are fixedly connected to the outer walls of the extension shaft 12 and the drive shaft 15 inside the gearbox 11. The helical gear 14 located on the first conveying screw 3 meshes with the helical gear 14 located on the second conveying screw 4.
[0025] In the specific implementation process, it is worth noting that through the cooperation between the first conveying screw 3, the second conveying screw 4, the extension shaft 12, the helical gear 14, and the drive shaft 15, one end of the first conveying screw 3 is the extension shaft 12, and the other end is the drive shaft 15 connected to the drive assembly 20. Both ends of the second conveying screw 4 are extension shafts 12. Helical gears 14 are installed on the outer walls of both the extension shaft 12 and the drive shaft 15. The helical gears 14 installed on the two screws mesh with each other. When the twin-screw extruder is working, the drive shaft 15 drives the first conveying screw 3 to rotate. Since the helical gears 14 on the first conveying screw 3 and the second conveying screw 4 mesh with each other, the second conveying screw 4 rotates in the opposite direction. This allows the first conveying screw 3 and the second conveying screw 4 to achieve synchronous and opposite rotational motion within the conveying cylinder 1, thereby effectively conveying and mixing the material. In addition to plasticizing, the meshing connection of the helical gear 14 ensures the stability and reliability of the screw during rotation, avoiding poor material processing due to asynchronous rotation or jamming. Through the cooperation between the conveying cylinder 1, the first conveying screw 3, the second conveying screw 4, the gearbox 11, the extension shaft 12, the sealed bearing 13, the helical gear 14 and the drive shaft 15, the structure of the conveying cylinder 1 and the twin screws is optimized. By adopting the bottom discharge method, both ends of the conveying screw can be effectively supported and fixed. Thus, helical gears 14 for transmission can be installed at both ends of the conveying screw. Compared with the end discharge method, it can effectively improve the stability and load-bearing capacity of the screw during rotation, avoid the screw bending or deformation due to uneven force, reduce friction and wear between the conveying structures, and extend the service life of the twin screw extruder.
[0026] Furthermore, the first conveying screw 3 and the second conveying screw 4 are provided with a barrier end plate 16 on the side of the feeding section 5 away from the wide-distance mixing section 6. The barrier end plate 16 is used to block the ends of the first conveying screw 3 and the second conveying screw 4 near the feeding section 5, so as to prevent harder particles from contacting the sealed bearing 13, preventing the particles from damaging the sealed bearing 13 and affecting the normal operation of the twin-screw extruder, and effectively preventing material leakage during the conveying process.
[0027] In the specific implementation process, it is worth noting that the barrier end plate 16 is used to block the ends of the first conveying screw 3 and the second conveying screw 4 near the feed section 5, so as to prevent harder particles from contacting the sealed bearing 13, prevent the particles from damaging the sealed bearing 13, affect the normal operation of the twin screw extruder, and effectively prevent material leakage during the conveying process.
[0028] Furthermore, shearing teeth 17 are equidistantly arranged on the outer wall of the feeding section 5, and the shearing teeth 17 located on the first conveying screw 3 are meshed with the shearing teeth 17 located on the second conveying screw 4.
[0029] In the specific implementation process, it is worth noting that, through the cooperation between the feeding section 5 and the shearing teeth 17, after the material enters the conveying cylinder 1 from the hopper above the feeding section 5, the material is initially sheared and crushed by the meshing shearing teeth 17, making the material finer and more uniform, thereby improving the effect of subsequent mixing and plasticizing.
[0030] Furthermore, exhaust grooves 18 are provided at equal intervals on the outer wall of one end of the cone-shaped melting section 7 near the wide-spacing mixing section 6;
[0031] In the specific implementation process, it is worth noting that through the cooperation between the conical melting section 7 and the exhaust groove 18, during the melting and homogenization process of the material in the conical melting section 7, the gas and volatiles in the material will be discharged in time through the exhaust groove 18, avoiding the accumulation of gas and volatiles in the material, which would affect the melting effect and product quality. It can effectively remove undesirable gases from the material and improve the purity and melting quality of the material.
[0032] This application also provides a twin-screw extruder, including a frame 19, a drive assembly 20, a heating module 21, and a threaded rod for the twin-screw extruder described above. The conveying cylinder 1 is fixedly connected to the top of the frame 19. The drive assembly 20 is drivenly connected to the first conveying screw 3. The heating modules 21 are equidistantly arranged on the outer wall of the conveying cylinder 1. The conveying cylinder 1 is located above the feeding section 5 and connected to the discharge hopper 22. The conveying cylinder 1 is located below the discharge straight rod section 9 and is provided with a discharge port 23.
[0033] In the specific implementation process, it is worth noting that the conveying cylinder 1 is installed on the top of the frame 19, and the drive assembly 20 includes a servo motor, a reducer, and a coupling. Through the cooperation between the conveying cylinder 1 and the drive assembly 20, the coupling connects the transmission shaft 15 located at one end of the first conveying screw 3 and the output shaft of the reducer. The servo motor provides power to the reducer, and after the reducer adjusts the speed of the servo motor, it drives the first conveying screw 3 to rotate through the coupling. The heating module 21 heats the conveying cylinder 1 and the material inside it to ensure that the material maintains an appropriate temperature during conveying and processing. The heating modules 21 at various locations... 1. Temperature can be adjusted independently to ensure that the material has different melting effects at different conveying stages, thereby improving the melting efficiency and quality of the material. Through the cooperation between the conveying cylinder 1, the first conveying screw 3, the second conveying screw 4, the drive assembly 20, the heating module 21, the hopper 22, and the discharge port 23, and by optimizing the conveying screw structure of the twin-screw extruder, the heating module 21 at different positions can be individually adjusted according to the melting state of the material at different positions during the material conveying process. This ensures that the material can obtain the best melting effect and processing quality at each stage of conveying, mixing, melting, and extrusion.
[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A threaded rod for a twin-screw extruder, comprising a conveying cylinder (1), characterized in that: The conveying cylinder (1) has an inner cavity (2) inside. A first conveying screw (3) is provided on one side of the inner cavity (2), and a second conveying screw (4) is provided on the side of the inner cavity (2) away from the first conveying screw (3). The first conveying screw (3) and the second conveying screw (4) are meshed together. One end of the first conveying screw (3) and the second conveying screw (4) are provided with a feeding section (5). The ends of the first conveying screw (3) and the second conveying screw (4) near the feeding section (5) are both provided with a wide-spaced mixing section (6). 4) A conical melting section (7) is provided on the side of the wide-spacing mixing section (6) away from the feeding section (5). A forward conveying section (8) is provided on the side of the first conveying screw (3) and the second conveying screw (4) away from the wide-spacing mixing section (6). A discharge straight rod section (9) is provided on the side of the first conveying screw (3) and the second conveying screw (4) away from the conical melting section (7) in the forward conveying section (8). A reverse conveying section (10) is provided on the side of the first conveying screw (3) and the second conveying screw (4) away from the forward conveying section (8) in the discharge straight rod section (9).
2. The threaded rod for a twin-screw extruder according to claim 1, characterized in that: Both ends of the conveying cylinder (1) are fixedly connected to gearboxes (11). The first conveying screw (3) is provided with an extension shaft (12) at one end near the reverse conveying section (10) and both ends of the second conveying screw (4). The first conveying screw (3) is provided with a drive shaft (15) at one end away from the reverse conveying section (10). The outer walls of the extension shaft (12) and the drive shaft (15) are fixedly connected with sealed bearings (13) at equal intervals. The outer walls of the sealed bearings (13) are fixedly connected to the gearbox (11). The outer walls of the extension shaft (12) and the drive shaft (15) are fixedly connected with helical gears (14) inside the gearbox (11). The helical gear (14) located on the first conveying screw (3) meshes with the helical gear (14) located on the second conveying screw (4).
3. The threaded rod for a twin-screw extruder according to claim 2, characterized in that: The first conveying screw (3) and the second conveying screw (4) are provided with a barrier end plate (16) on the side of the feeding section (5) away from the wide-distance mixing section (6).
4. The threaded rod for a twin-screw extruder according to claim 3, characterized in that: The outer wall of the feeding section (5) is provided with shearing teeth (17) at equal intervals. The shearing teeth (17) located on the first conveying screw (3) are engaged with the shearing teeth (17) located on the second conveying screw (4).
5. The threaded rod for a twin-screw extruder according to claim 4, characterized in that: The outer wall of the cone-shaped melting section (7) near the wide-spacing mixing section (6) is provided with exhaust grooves (18) at equal intervals.
6. A twin-screw extruder, characterized in that: The device includes a frame (19), a drive assembly (20), a heating module (21), and a threaded rod for a twin-screw extruder as described in any one of claims 1 to 5. The conveying cylinder (1) is fixedly connected to the top of the frame (19). The drive assembly (20) is driven by the first conveying screw (3). Heating modules (21) are equidistantly arranged on the outer wall of the conveying cylinder (1). The conveying cylinder (1) is connected to a hopper (22) above the feeding section (5). The conveying cylinder (1) is provided with a discharge port (23) below the discharge straight rod section (9).