Screw for double-screw extruder

Abstract

The utility model relates to a screw for a double-screw extruder, which comprises a mandrel and a threaded block, one end of the mandrel is provided with a spline, the other end of the mandrel is fixedly provided with a limit block, and the body of the mandrel is provided with external threads; the threaded block at least comprises a forward conveying block, a reverse conveying block and a kneading block; a penetrating hole is formed in the center of each threaded block, internal threads matched with the external threads of the mandrel are arranged on the hole wall of each penetrating hole, and the N threaded blocks are connected to the mandrel in a threaded mode. The screw for the double-screw extruder can solve the problems that the screw of the existing double-screw extruder cannot be independently replaced and adjusted due to the adoption of an integral design, the whole screw needs to be replaced once the screw is worn or damaged, and the maintenance cost and the downtime are increased; the problem that the production efficiency and the product quality are difficult to optimize in the face of diversified production tasks due to the facts that the production efficiency and the product quality cannot be adjusted according to the processing requirements of different materials due to the lack of flexibility is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of extruders, in particular to a screw for a twin-screw extruder. Background Art

[0002] In modern industrial production, extruders are widely used in industries such as plastics, rubber, food and chemicals. The core component of an extruder is the screw, whose structure and performance directly affect the working efficiency and product quality of the extruder. At present, the extruders on the market are mainly divided into single-screw extruders and twin-screw extruders. Among them, twin-screw extruders are widely used in occasions with high requirements for materials due to their high mixing, plasticizing and conveying capabilities.

[0003] Existing twin-screw extruder screws usually adopt an integral design, that is, the threaded part on the screw is formed in one piece and cannot be replaced and adjusted separately. Once the screw is worn or damaged, the entire screw needs to be replaced, increasing maintenance costs and downtime; and the integral screw structure lacks flexibility and cannot be adjusted according to the processing requirements of different materials, resulting in difficulty in optimizing production efficiency and product quality when facing diversified production tasks.

[0004] Therefore, the prior art has defects and needs to be improved and developed. Summary of the invention

[0005] The embodiment of the utility model provides a screw for a twin-screw extruder, which is used to solve the problem that the existing twin-screw extruder screws in the prior art usually adopt an integral design, that is, the threaded part on the screw is formed in one piece and cannot be replaced and adjusted separately. Once the screw is worn or damaged, the entire screw needs to be replaced, which increases maintenance costs and downtime; and the integral screw structure lacks flexibility and cannot be adjusted according to the processing requirements of different materials, resulting in the problem that production efficiency and product quality are difficult to optimize when facing diversified production tasks.

[0006] The utility model embodiment provides a screw for a twin-screw extruder, comprising a core shaft and a threaded block, wherein one end of the core shaft is provided with a spline, the other end of the core shaft is fixed with a limit block, and the shaft body of the core shaft is provided with an external thread; the threaded block comprises at least a forward conveying block with a threaded outer wall, a reverse conveying block with a thread direction opposite to that of the forward conveying block, and a kneading block with a tooth-shaped outer wall; a through hole is provided at the center of the threaded block, and an internal thread adapted to the external thread of the core shaft is provided on the hole wall of the through hole, and N of the threaded blocks are threadedly connected to the core shaft, wherein N is a natural number greater than 1.

[0007] Furthermore, the number of the forward conveying blocks is greater than 1, and the lead sizes of any two of the forward conveying blocks are different.

[0008] Furthermore, the number of the reverse conveying blocks is greater than 1, and the lead sizes of any two reverse conveying blocks are different.

[0009] Furthermore, the number of the kneading blocks is greater than 1, and the included angle of any two adjacent tooth shapes of any kneading block is the same, and the included angle is one of 30°, 45°, 60° and 90°.

[0010] Furthermore, the aspect ratio of the mandrel is 36:1.

[0011] Furthermore, when N threaded blocks are threadedly connected to the core shaft, any adjacent threaded blocks are detachably connected with locking members, and the locking members are used to fix the adjacent threaded blocks.

[0012] Furthermore, the locking member is a locking nut threadedly connected to the core shaft.

[0013] Furthermore, the locking member is two nuts which are threadedly connected to the core shaft and have different thicknesses, and the thickness of the nut near the spline end is smaller than the thickness of the nut near the limit block end.

[0014] Furthermore, the locking member is a spring washer sleeved on the core shaft.

[0015] Furthermore, the spring washer is at least one of a carbon steel spring washer and a stainless steel spring washer.

[0016] Beneficial effects:

[0017] It can be seen from the above technical scheme that the utility model provides a screw for a twin-screw extruder. First, the flexibility of the screw is enhanced through a detachable design: the detachable thread block structure is adopted, so that the thread block can be arbitrarily disassembled and installed according to actual needs. When facing different materials and process requirements, the thread block can be quickly replaced, which significantly improves the flexibility and adaptability of the screw; the detachable thread block design allows the thread structure and configuration of the screw to be adjusted according to specific processing requirements, thereby optimizing the extrusion, mixing and plasticizing effects, and improving production efficiency and product quality. Second, maintenance is convenient and costs are reduced: when part of the thread block is worn or damaged, only the corresponding thread block needs to be replaced without replacing the entire screw, which reduces maintenance costs and time; enterprises can reduce downtime, maintain continuous production, and improve the utilization rate of the production line. Third, modular design has wide applicability: through the modular thread block design, different types of thread blocks can be quickly configured and replaced according to different processing requirements, so that the twin-screw extruder is suitable for more types of materials and process requirements, and the scope of application of the extruder is expanded; modular design not only improves the versatility of the equipment, but also enables the production line to quickly respond to changes in market demand and adapt to the trend of diversification and small batch production. Fourth, improve work efficiency and product quality: the design of the detachable thread block allows adjustment and optimization as needed during the production process, ensuring the best mixing and plasticizing effect, and improving product consistency and quality; because the screw thread structure and configuration can be optimized according to specific needs, the twin-screw extruder can maintain an efficient working state under different process conditions and improve overall production efficiency. Fifth, extend the service life of the equipment: by replacing a single thread block instead of the entire screw, the equipment wear and aging caused by frequent screw replacement is avoided, the service life of the extruder is extended, and the equipment depreciation and replacement frequency are reduced.

[0018] The design of the detachable thread block makes maintenance and replacement easier. Ordinary operators can complete the disassembly and assembly of the thread block, reducing the dependence on professional technology and tools, and further reducing the difficulty and cost of maintenance.

[0019] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent.

[0020] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are not drawn to scale according to actual reference objects. In the accompanying drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the accompanying drawings, in which:

[0022] Figure 1 This is a schematic diagram of the structure of a screw for a twin-screw extruder in an embodiment of the present application.

[0023] Description of Figure Numbers:

[0024] Mandrel 1; spline 2; limit block 3; conveying section 4; melting section 5; first mixing section 6; second mixing section 7; third mixing section 8; exhaust section 9; homogenizing section 10. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meaning understood by people with general skills in the field to which the present invention belongs.

[0026] The words "first", "second" and similar terms used in the patent specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form "a" or "an" shall not be construed as "a" or "an";

[0027] The words “a”, “an”, “the” and the like do not denote a limitation of quantity, but rather denote the presence of at least one.

[0028] The words "include" or "comprises" and the like mean that the elements or objects appearing before "includes" or "comprises" include the features, wholes, steps, operations, elements and / or components listed after "includes" or "comprises", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] In the prior art, the screw of the existing twin-screw extruder usually adopts an integral design, that is, the threaded part on the screw is formed in one piece and cannot be replaced and adjusted separately. Once the screw is worn or damaged, the entire screw needs to be replaced, which increases maintenance costs and downtime; and the integral screw structure lacks flexibility and cannot be adjusted according to the processing requirements of different materials, resulting in difficulty in optimizing production efficiency and product quality when facing diversified production tasks.

[0030] In view of this, an embodiment of the utility model provides a screw for a twin-screw extruder, including a core shaft 1 and a threaded block. A spline 2 is provided at one end of the core shaft 1 for mounting the screw for the twin-screw extruder on a rotor configured for the extruder. A limiting block 3 is fixed at the other end of the core shaft 1 for limiting the slipping of the threaded block. An external thread is provided on the shaft body of the core shaft 1; the threaded block includes at least a forward conveying block with a threaded outer wall, a reverse conveying block with a thread direction opposite to that of the forward conveying block, and a kneading block with a tooth-shaped outer wall; a through hole is provided at the center of the threaded block, and an internal thread matching the external thread of the core shaft 1 is provided on the wall of the through hole, and N threaded blocks are threadedly connected to the core shaft 1, where N is a natural number greater than 1.

[0031] In some embodiments, the number of forward conveying blocks is greater than 1, and the lead sizes of any two forward conveying blocks are different. The forward conveying blocks are used for material, that is, raw material transportation, and the lead of the forward conveying blocks varies. The larger the lead, the faster the material transportation.

[0032] In some embodiments, the number of reverse conveying blocks is greater than 1, and the lead sizes of any two reverse conveying blocks are different. The function of the reverse conveying block is reverse conveying to increase the residence time of the material so that the material is fully plasticized.

[0033] In some embodiments, the number of kneading blocks is greater than 1, and the included angle of any two adjacent tooth shapes of any kneading block is the same, and the included angle is one of 30°, 45°, 60° and 90°. The function of the kneading block is to shear the material through the tooth shapes at various angles to make the material smaller.

[0034] In some embodiments, the length-to-diameter ratio of the mandrel 1 is 36:1.

[0035] In some embodiments, when N threaded blocks are threadedly connected to the core shaft 1, locking members are detachably connected between any adjacent threaded blocks, and the locking members are used to fix the adjacent threaded blocks.

[0036] In some embodiments, the locking member is a locking nut threadedly connected to the mandrel 1. When in use, a locking nut is used between every two adjacent threaded blocks. The locking nut is prevented from loosening by its special design (such as nylon inserts, metal lock pieces), and the adjacent threaded blocks are fixed after the locking nut is tightened. When disassembling, the locking nut is loosened using a wrench or other tools, and then the threaded blocks are removed.

[0037] In some embodiments, the locking member is two nuts of different thicknesses that are threadedly connected to the mandrel 1, and the thickness of the nut near the spline 2 is less than the thickness of the nut near the stop block 3. When in use, two nuts are added to one end of each threaded block, and the first nut is tightened first, and then the second nut is tightened, so that the two nuts are pressed against each other to prevent loosening. When disassembling, loosen the two nuts in turn, and then rotate the threaded block for disassembly.

[0038] In some embodiments, the locking member is a spring washer sleeved on the core shaft 1. When in use, a spring washer is placed between each threaded block, and the elasticity of the spring washer increases the friction force to prevent the threaded block from loosening. When disassembling, first loosen the spring washer and then remove the threaded block.

[0039] In some embodiments, the spring washer is at least one of a carbon steel spring washer and a stainless steel spring washer.

[0040] Reference Figure 1 , a twin-screw extruder screw provided by the embodiment of the utility model is used to design a structure that meets actual needs, the structure includes two twin-screw extruder screws parallel to each other, the threads in the thread blocks on the two twin-screw extruder screws run in opposite directions and mesh with each other, and any twin-screw extruder screw includes a conveying section 4, a melting section 5, a first mixing section 6, a second mixing section 7, a third mixing section 8, a venting section 9 and a homogenizing section 10 in sequence from the left core shaft 1 to the right limit block 3. Locking parts are provided between adjacent thread blocks in the conveying section 4, the melting section 5, the first mixing section 6, the second mixing section 7, the third mixing section 8, the venting section 9 and the homogenizing section 10.

[0041] Among them, the conveying section 4 is used for preheating and conveying raw materials, and includes 3 forward conveying blocks. From left to right, the lead of the first forward conveying block is smaller than the lead of the second forward conveying block, and the lead of the second forward conveying block is equal to the lead of the third forward conveying block.

[0042] The melting section 5 is used for melting and mixing raw materials, and includes 7 forward conveying blocks, each of which has the same lead, and the lead of the forward conveying block in the melting section 5 is between the lead of the first forward conveying block and the lead of the second forward conveying block in the conveying section 4.

[0043] The first mixing section 6, the second mixing section 7 and the third mixing section 8 are all used to change the physical properties of the principle and produce plasticization.

[0044] The first mixing section 6 includes three kneading blocks, and from left to right, the angle between the teeth of the first kneading block is greater than the angle between the teeth of the second kneading block, and the angle between the teeth of the second kneading block is equal to the angle between the teeth of the third kneading block.

[0045] The second kneading section 7 includes, from left to right, three forward conveying blocks having the same lead as the forward conveying blocks of the melting section 5, three kneading blocks having the same arrangement as the three kneading blocks in the first kneading section 6, and one kneading block having tooth shapes with an included angle between the included angle between the tooth shapes of the first kneading block and the included angle between the tooth shapes of the second kneading block in the first kneading section 6.

[0046] The third kneading section 8 includes, from left to right, five forward conveying blocks having the same lead as the forward conveying blocks of the melting section 5 , and two kneading blocks that are the same as the second kneading blocks in the first kneading section 6 .

[0047] The exhaust section 9 is used to exhaust water vapor and gas generated during the plasticization process by natural exhaust or vacuuming through the open barrel in the extruder. The exhaust section 9 includes 4 forward conveying blocks with the same lead as the forward conveying blocks of the melting section 5.

[0048] The homogenizing section 10 is used to mix the plasticized raw materials uniformly again in the cylinder, and includes, from left to right, 3 forward conveying blocks with the same lead as the forward conveying block of the melting section 5, a kneading block with the same angle between the tooth shapes as the angle between the tooth shapes of the second kneading block in the first mixing section 6, and 6 forward conveying blocks with the same lead as the forward conveying block of the melting section 5.

[0049] In summary, the utility model provides a twin-screw extruder screw, which has a detachable thread block, and a locking member is designed to ensure that the thread blocks can be fixed to each other, so as to achieve stable operation, significantly enhance the flexibility and adaptability of the extruder, simplify the maintenance and replacement process, reduce maintenance costs, improve work efficiency and product quality, expand the scope of application of the equipment, and extend the service life of the equipment, with significant advantages and beneficial effects. First, the flexibility of the screw is enhanced by the detachable design: the detachable thread block structure is adopted, so that the thread block can be freely disassembled and installed according to actual needs, and the thread block can be quickly replaced when facing different materials and process requirements, which significantly improves the flexibility and adaptability of the screw; the detachable thread block design allows the thread structure and configuration of the screw to be adjusted according to specific processing requirements, thereby optimizing the extrusion, mixing and plasticizing effects, and improving production efficiency and product quality. Second, maintenance is convenient and costs are reduced: when part of the thread block is worn or damaged, only the corresponding thread block needs to be replaced without replacing the entire screw, which reduces maintenance costs and time; enterprises can reduce downtime, maintain continuous production, and improve the utilization rate of the production line. Third, modular design and wide applicability: Through the modular thread block design, different types of thread blocks can be quickly configured and replaced according to different processing requirements, making the twin-screw extruder suitable for more types of materials and process requirements, expanding the scope of application of the extruder; modular design not only improves the versatility of the equipment, but also enables the production line to quickly respond to changes in market demand and adapt to the trend of diversified and small-batch production. Fourth, improve work efficiency and product quality: The design of the detachable thread block allows adjustment and optimization as needed during the production process, ensuring the best mixing and plasticizing effect, and improving product consistency and quality; because the thread structure and configuration of the screw can be optimized according to specific needs, the twin-screw extruder can maintain an efficient working state under different process conditions, improving overall production efficiency. Fifth, extend the service life of the equipment: by replacing a single thread block instead of the entire screw, the wear and aging of the equipment caused by frequent replacement of the screw is avoided, the service life of the extruder is extended, and the depreciation and replacement frequency of the equipment are reduced.

[0050] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A screw for a twin-screw extruder, characterized in that: It includes a core shaft and a threaded block, one end of the core shaft is provided with a spline, the other end of the core shaft is fixed with a limit block, and the shaft body of the core shaft is provided with an external thread; the threaded block at least includes a forward conveying block with a threaded outer wall, a reverse conveying block with a thread direction opposite to that of the forward conveying block, and a kneading block with a toothed outer wall; a through hole is provided at the center of the threaded block, and the hole wall of the through hole is provided with an internal thread adapted to the external thread of the core shaft, and N threaded blocks are threadedly connected to the core shaft, where N is a natural number greater than 1.

2. A twin-screw extruder screw according to claim 1, characterized in that: The number of the forward conveying blocks is greater than 1, and the lead sizes of any two of the forward conveying blocks are different.

3. A twin-screw extruder screw according to claim 2, characterized in that: The number of the reverse conveying blocks is greater than 1, and the lead sizes of any two reverse conveying blocks are different.

4. A twin-screw extruder screw according to claim 3, characterized in that: The number of the kneading blocks is greater than 1, and the included angle between any two adjacent tooth shapes of any kneading block is the same, and the included angle is one of 30°, 45°, 60° and 90°.

5. A twin-screw extruder screw according to claim 4, characterized in that: The length-to-diameter ratio of the mandrel is 36:

1.

6. A twin-screw extruder screw according to claim 5, characterized in that: When N threaded blocks are threadedly connected to the core shaft, any adjacent threaded blocks are detachably connected with locking members, and the locking members are used to fix the adjacent threaded blocks.

7. A twin-screw extruder screw according to claim 6, characterized in that: The locking member is a locking nut threadedly connected to the core shaft.

8. A twin-screw extruder screw according to claim 6, characterized in that: The locking member is two nuts with different thicknesses which are threadedly connected to the core shaft, and the thickness of the nut near the spline end is smaller than the thickness of the nut near the limit block end.

9. A twin-screw extruder screw according to claim 6, characterized in that: The locking member is a spring washer sleeved on the core shaft.

10. A screw for a twin-screw extruder according to claim 9, characterized in that: The spring washer is at least one of a carbon steel spring washer and a stainless steel spring washer.

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