An ultra-long small taper twin-screw extruder for plastic recycling

Abstract

The present invention relates to the technical field of extruder exhaust, and discloses an ultra-long small taper double-barrel screw extruder for plastic recycling. The material is conveyed forward inside the barrel, and the heater heats the inside of the barrel, so that the material melts inside the barrel. Then, the melted material is extruded from the other end of the barrel. At the same time, the driving moving part moves, so that the moving part moves in an "8" - shaped trajectory inside the barrel. The moving part drives the lever to move, so that the lever flips the material inside the barrel to help the bubbles in the material escape, thereby forming a stirring action on the melted material inside the barrel, making the melted material flip at the position of the exhaust port to assist the melted material in exhausting gas. In this way, the exhaust efficiency is improved within a specific exhaust time period, the bubble content in the melted material is reduced, the influence of bubbles on the extrusion molding of the material is avoided, and the production quality of the extruder is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of extruder exhaust, and specifically relates to an ultra-long small taper double-barrel screw extruder for plastic recycling. Background Art

[0002] The principle of an extruder is to use a screw with a specific shape to rotate in a heated barrel. The surface of the screw is provided with working sections with different groove shapes, and each working section has a different function. The plastic sent from the hopper is pushed forward, making the plastic uniformly melt. Through the head and different-shaped molds, the plastic is extruded into continuous plastic layers of various required shapes.

[0003] In existing extruders, such as Chinese Patent Application CN113492513A, through the setting of double-screw extrusion elements, several groups of axially arranged pin groups are provided on the screw edges of the screws of the double-screw extruder, which can increase the number of fluid streamline bundles, causing the material to continuously separate, merge, cross or change direction during the flow process, effectively dividing the material, changing the material flow condition, and thus enhancing the mixing ability of the screw.

[0004] However, the following problems still exist: Limited by the size of the exhaust port, there is less exhaust time for the bubbles remaining in the molten material in the barrel, and it is very easy for bubbles to still exist in the molten material, which affects the extrusion molding of subsequent materials and reduces the production quality of the extruder. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides an ultra-long small taper double-barrel screw extruder for plastic recycling, which has the advantages of forming a stirring action on the molten material in the barrel, making the molten material turn over at the position of the exhaust port to assist the molten material in exhausting gas, thereby improving the exhaust efficiency within a specific exhaust time period, reducing the bubble content in the molten material, avoiding the influence of bubbles on the extrusion molding of the material, and improving the production quality of the extruder, etc. It solves the problem that limited by the size of the exhaust port, there is less exhaust time for the bubbles remaining in the molten material in the barrel, and it is very easy for bubbles to still exist in the molten material, which affects the extrusion molding of subsequent materials and reduces the production quality of the extruder.

[0006] To achieve the above object, the present invention provides the following technical solution: An ultra-long small taper double-barrel screw extruder for plastic recycling, including a base, an extrusion mechanism arranged on the base, and an auxiliary mechanism arranged on the extrusion mechanism. The extrusion mechanism includes a heater and a barrel. The heater is fixedly installed on the base and is used for melting the material. The barrel is arranged on the base and penetrates through the heating area of the heater. The barrel is used for transporting and processing the material;

[0007] The auxiliary mechanism includes a moving member and a dial rod. The moving member is movably arranged in the barrel. The moving member is located in the exhaust area of the extruder. The shape of the moving member is adapted to the shape of the inner wall of the barrel. A plurality of the dial rods are fixedly installed on the inner annular wall surface of the moving member. The dial rods are evenly distributed on the moving member. The length of the dial rod is adapted to the length of the exhaust area of the extruder. The dial rod moves synchronously with the moving member.

[0008] Preferably, the extrusion mechanism further includes a machine cover plate. The machine cover plate is fixedly installed on the base. A barrel support is arranged inside the machine cover plate. The barrel support is fixedly installed on the base. The barrel support penetrates through both ends of the machine cover plate. A feed hopper is fixedly installed on the machine cover plate. The bottom end of the feed hopper penetrates through the wall surface of the machine cover plate. The bottom end of the feed hopper penetrates through the barrel support. The bottom end of the feed hopper is communicated with the barrel. The barrel penetrates through the heating area of the heater.

[0009] Preferably, a main motor is fixedly installed on the base. A coupling is fixedly installed on the shaft of the main motor. A gear set is arranged on the base. One end of the gear set is power-connected to the coupling. The other end of the gear set extends into the barrel. A first screw is arranged in the barrel. A second screw is arranged in the barrel. The first screw is thread-fitted with the second screw. The gear set is power-connected to the first screw. The gear set is power-connected to the second screw, so that the first screw and the second screw rotate relative to each other.

[0010] Preferably, a plurality of exhaust ports are formed in the barrel. The exhaust ports are located in the exhaust area of the extruder. The exhaust ports are communicated with the inside of the machine cover plate. One end of the barrel is fixedly installed with a discharge port. The discharge port is communicated with the barrel. The discharge port penetrates through the barrel support. The discharge port penetrates through the machine cover plate.

[0011] Preferably, the interior of the barrel includes multiple regions. At one end inside the barrel, there is a feeding section for conveying the material. Inside the barrel, there is a pre-plasticizing section adjacent to the feeding section, which is used for heating and softening the material. Inside the barrel, there is a kneading section a adjacent to the pre-plasticizing section, which is used for mixing and shearing the material. Inside the barrel, there is a compression section a adjacent to the kneading section a, which is used for compacting the material. Inside the barrel, there is a venting section a adjacent to the compression section a, which is used for venting the material. Inside the barrel, there is a kneading section b adjacent to the venting section a, which is used for mixing and shearing the material again. Inside the barrel, there is a compression section b adjacent to the kneading section b, which is used for compacting the material again. Inside the barrel, there is a venting section b adjacent to the compression section b, which is used for venting the material again. Inside the barrel, there is an extrusion section adjacent to the venting section b, which is used for extruding the material. At the kneading section a, the first screw and the second screw are both fixed with a plurality of toothed first shear teeth, and the first shear teeth on the first screw and the second screw mesh with each other. At the kneading section b, the first screw and the second screw are successively fixed with a screw edge a, toothed second shear teeth, a screw edge b, and a screw edge c, and the second shear teeth on the first screw and the second screw mesh with each other.

[0012] Preferably, the first screw and the second screw have the same structure and are both small conical screws. Their diameters gradually decrease along the material conveying direction. The diameter at the end far from the discharge port is D1, and the diameter at the end close to the discharge port is D2. Their length is L, and their cone angle is α, where tanα = (D1 - D2) / 2 / L, and tanα ranges from 0.001 to 0.009. Their length-diameter ratio is A, where A = L / D2, and A ranges from 30 to 40.

[0013] Preferably, the auxiliary mechanism further includes a first receiving notch. A plurality of the first receiving notches are formed in the barrel. The first receiving notches are symmetrically distributed on both sides of the exhaust port and are adjacent to the exhaust port. The shape of the first receiving notch is the same as the shape of the inner wall surface of the barrel. A first annular rail is fixedly installed in the first receiving notch. The shape of the first annular rail is the same as the shape of the first receiving notch. The size of the first annular rail is adapted to the size of the first receiving notch. The first annular rail is sealed with the barrel. A moving member is movably installed on the first annular rail. The shape of the moving member is the same as the shape of the first annular rail. The moving member penetrates the wall surface of the first annular rail. The moving member is sealed with the first annular rail.

[0014] Preferably, a toothed belt is fixedly installed on the outer ring of the moving member. The shape of the toothed belt is the same as the shape of the moving member. The toothed belt penetrates the barrel bracket. A plurality of auxiliary gears are rotatably engaged with the barrel bracket. The auxiliary gears are meshed with the toothed belt. A first traction wheel is fixedly installed on the shaft of the auxiliary gear.

[0015] Preferably, a servo motor is fixedly installed on the base. The servo motor is located inside the machine cover plate. A second traction wheel is fixedly installed on the shaft of the servo motor. A belt is tensioned between the second traction wheel and the first traction wheel.

[0016] Preferably, a second receiving notch is formed in the barrel. The shape of the second receiving notch is the same as the shape of the inner wall of the barrel. A second annular rail is fixedly installed on the second receiving notch. The shape of the second annular rail is the same as the shape of the second receiving notch. A protective collar is movably installed on the inner ring of the second annular rail. The shape of the protective collar is the same as the shape of the second annular rail. A plurality of ball screws are provided between the protective collar and the second annular rail. The ball screws are evenly distributed between the protective collar and the second annular rail.

[0017] Compared with the prior art, the present invention provides an ultra-long small taper double-screw extruder for plastic recycling, having the following beneficial effects:

[0018] 1. The ultra-long small taper double-screw extruder for plastic recycling first feeds the material into one end of the barrel. The material is transported forward inside the barrel. The heater is started, and the heater heats the inside of the barrel, causing the material to melt inside the barrel. Then, the melted material is extruded from the other end of the barrel. At the same time, the moving part is driven to move, so that the moving part moves in an "8" - shaped trajectory inside the barrel. The moving part drives the lever to move, causing the lever to turn over the material inside the barrel, thereby assisting the material to turn over in the exhaust area to help the bubbles in the material escape, thus forming a stirring action on the melted material inside the barrel, making the melted material turn over at the position of the exhaust port to assist the melted material in exhausting. In this way, the exhaust efficiency is improved within a specific exhaust time period, the bubble content in the melted material is reduced, the influence of bubbles on the extrusion molding of the material is avoided, and the production quality of the extruder is improved.

[0019] 2. The ultra-long small taper double-screw extruder for plastic recycling, through the setting of the first receiving slot and the first annular rail, enables the auxiliary mechanism to be better installed inside the barrel, improving the operating stability of the extruder.

[0020] 3. The ultra-long small taper double-screw extruder for plastic recycling, through the setting of the protective collar, when the first screw or the second screw touches the protective collar, the first screw or the second screw drives the protective collar to move on the second annular rail, so that the first screw and the second screw do not generate a large amount of friction with the inner wall of the barrel. And the ball screw reduces the friction between the protective collar and the second annular rail, reducing the frictional contact between the screw and the barrel, and improving the service life of the screw and the barrel. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the extruder of the present invention;

[0022] Figure 2 It is a schematic diagram of the structure of the extrusion mechanism of the present invention;

[0023] Figure 3 It is a schematic diagram of the structural distribution at the feed hopper of the present invention;

[0024] Figure 4 It is an exploded schematic diagram of the structural distribution of the barrel, the first screw and the second screw of the present invention;

[0025] Figure 5 It is a schematic plan view of the working area distribution inside the barrel of the present invention;

[0026] Figure 6 It is a schematic diagram of the structure of the auxiliary mechanism of the present invention;

[0027] Figure 7 It is a schematic diagram of the structural distribution at the belt of the present invention;

[0028] Figure 8 Schematic diagram of the structural distribution at the lever of the present invention;

[0029] Figure 9 Schematic diagram of the structural distribution at the second receiving slot of the present invention;

[0030] Figure 10 Schematic diagram of the internal structural distribution of the second annular rail of the present invention;

[0031] Figure 11 Schematic diagram of the unified planar identification of the first screw and the second screw of the present invention.

[0032] In the figure: 1. Base; 2. Extrusion mechanism; 21. Machine cover plate; 22. Barrel support; 23. Feeding hopper; 24. Heater; 25. Main motor; 26. Coupling; 27. Gear set; 28. Barrel; 29. First screw; 210. Second screw; 211. Exhaust port; 212. Discharge port; 213. Feeding section; 214. Pre-plasticizing section; 215. Kneading section a; 216. Compression section a; 217. Exhaust section a; 218. Kneading section b; 219. Compression section b; 220. Exhaust section b; 221. Extrusion section; 3. Auxiliary mechanism; 31. First receiving slot; 32. First annular rail; 33. Moving part; 34. Lever; 35. Tooth belt; 36. Auxiliary gear; 37. First traction wheel; 38. Servo motor; 39. Second traction wheel; 310. Belt; 311. Second receiving slot; 312. Second annular rail; 313. Protective collar; 314. Ball screw. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] As introduced in the background art, there are deficiencies in the prior art. To solve the above technical problems, the present application proposes an ultra-long small taper double-barrel screw extruder for plastic recycling.

[0035] Embodiment 1

[0036] In a typical implementation manner of the present application, as Figures 1 - 2As shown in the figure, an ultra-long small taper twin-screw extruder for plastic recycling includes a base 1, an extrusion mechanism 2 arranged on the base 1, and an auxiliary mechanism 3 arranged on the extrusion mechanism 2. The extrusion mechanism 2 includes a heater 24 and a barrel 28. The heater 24 is fixedly installed on the base 1 and is used for melting the material. The barrel 28 is arranged on the base 1 and penetrates through the heating area of the heater 24. The barrel 28 is used for conveying and processing the material.

[0037] The auxiliary mechanism 3 includes a moving part 33 and a dial rod 34. The moving part 33 is movably arranged in the barrel 28. The moving part 33 is located in the exhaust area of the extruder. The shape of the moving part 33 is adapted to the shape of the inner wall of the barrel 28. A plurality of dial rods 34 are fixedly installed on the inner ring wall surface of the moving part 33. The dial rods 34 are evenly distributed on the moving part 33. The length of the dial rod 34 is adapted to the length of the exhaust area of the extruder. The dial rod 34 moves synchronously with the moving part 33.

[0038] Specifically, the inner shape of the barrel 28 is an "8" - shaped structure, and the shape of the moving part 33 is an "8" - shaped structure.

[0039] When using the present invention:

[0040] First, the material is fed into one end of the barrel 28, and the material is conveyed forward inside the barrel 28. The heater 24 is started, and the heater 24 heats the inside of the barrel 28, causing the material to melt inside the barrel 28. Then, the melted material is extruded from the other end of the barrel 28. At the same time, the moving part 33 is driven to move, so that the moving part 33 moves in an "8" - shaped trajectory inside the barrel 28. The moving part 33 drives the dial rod 34 to move, so that the dial rod 34 flips the material inside the barrel 28, thereby assisting the material to flip in the exhaust area to help the bubbles in the material escape, thus forming a stirring action on the melted material inside the barrel, making the melted material flip at the position of the exhaust port to assist the melted material in exhausting. In this way, the exhaust efficiency is improved within a specific exhaust time period, the bubble content in the melted material is reduced, the influence of bubbles on the extrusion molding of the material is avoided, and the production quality of the extruder is improved.

[0041] Embodiment 2

[0042] As Figures 3 - 5As shown, the difference from the above embodiment is that the extrusion mechanism 2 further includes a machine cover plate 21. The machine cover plate 21 is fixedly installed on the base 1. Inside the machine cover plate 21, there is a barrel support 22. The barrel support 22 is fixedly installed on the base 1. The barrel support 22 penetrates through both ends of the machine cover plate 21. A feed hopper 23 is fixedly installed on the machine cover plate 21. The bottom end of the feed hopper 23 penetrates through the wall surface of the machine cover plate 21 and the barrel support 22. The bottom end of the feed hopper 23 is communicated with the barrel 28. The barrel 28 penetrates through the heating area of the heater 24.

[0043] Further, a main motor 25 is fixedly installed on the base 1. A coupling 26 is fixedly installed on the shaft of the main motor 25. A gear set 27 is arranged on the base 1. One end of the gear set 27 is power-connected to the coupling 26. The other end of the gear set 27 extends into the barrel 28. A first screw 29 is arranged in the barrel 28. A second screw 210 is arranged in the barrel 28. The first screw 29 is threadedly matched with the second screw 210. The gear set 27 is power-connected to the first screw 29 and the gear set 27 is power-connected to the second screw 210, so that the first screw 29 and the second screw 210 rotate relative to each other.

[0044] Further, a plurality of exhaust ports 211 are opened on the barrel 28. The exhaust ports 211 are located in the exhaust area of the extruder. The exhaust ports 211 are communicated with the inside of the machine cover plate 21. One end of the barrel 28 is fixedly installed with a discharge port 212. The discharge port 212 is communicated with the barrel 28. The discharge port 212 penetrates through the barrel support 22 and the machine cover plate 21.

[0045] Further, the inside of the barrel 28 includes a plurality of areas. At one end inside the barrel 28, there is a feeding section 213 for conveying materials. Inside the barrel 28, there is a pre-plasticizing section 214 adjacent to the feeding section 213 for heating and softening the materials. Inside the barrel 28, there is a mixing section a215 adjacent to the pre-plasticizing section 214 for mixing and shearing the materials. Inside the barrel 28, there is a compression section a216 adjacent to the mixing section a215 for compacting the materials.

[0046] Further, an exhaust section a217 is provided inside the barrel 28. The exhaust section a217 is adjacent to the compression section a216. The exhaust section a217 is used for exhausting the material. A kneading section b218 is provided inside the barrel 28. The kneading section b218 is adjacent to the exhaust section a217. The kneading section b218 is used for mixing and shearing the material again. A compression section b219 is provided inside the barrel 28. The compression section b219 is adjacent to the kneading section b218. The compression section b219 is used for compacting the material again. An exhaust section b220 is provided inside the barrel 28. The exhaust section b220 is adjacent to the compression section b219. The exhaust section b220 is used for exhausting the material again. An extrusion section 221 is provided inside the barrel 28. The extrusion section 221 is adjacent to the exhaust section b220. The extrusion section 221 is used for extruding the material.

[0047] Among them, the feeding section 213: Its main function is to convey the material and prevent the material from flowing back. The screw in this section is similar to the conveying section of a single-screw extruder, which smoothly conveys materials such as plastic particles from the hopper to the inside of the extruder, preparing for the subsequent processing process;

[0048] The pre-plasticizing section 214: Initially heats and softens the plastic raw material, and fully mixes the raw material through stirring and heating to ensure the stability of product quality and the consistency of performance. Through heat transfer and frictional shearing, the material is fully melted and homogenized. In this section, the material begins to gradually change from a solid state to a molten state, providing conditions for the next kneading and processing. Heat transfer is where heating occurs, and frictional shearing is achieved through the threads of the screw;

[0049] The kneading section a215: Kneading is carried out by the mutual meshing of the toothed first shearing teeth, which can fully mix and shear the material, enabling different material components to be fully mixed and reach a uniform state;

[0050] The compression section a216: Further compacts the material in the compression section after the kneading section. After kneading, the material may still be relatively loose. The compression section applies pressure to the material through the action of components such as the screw, compacts it, makes the material more dense, and discharges the air in the material, preparing for the subsequent exhaust section. During the compression process, due to the material being subjected to higher pressure and appropriate shear force, it helps for better dispersion;

[0051] The exhaust section a217: When the material is conveyed to the exhaust section by the screw, the gas in the material (such as water vapor formed by the evaporation of moisture, air entrained in the raw material, etc.) will be discharged under vacuum or normal pressure. The thread distribution gap in the exhaust section is relatively large. The relatively large thread gap can provide sufficient escape space and channels for the gas, enabling the gas to be smoothly separated from the material and discharged out of the extruder through the opening of the exhaust section;

[0052] Mixing section b218: The first screw 29 and the second screw 210 are both fixedly provided with a thread edge a, a toothed second shear tooth, a thread edge b, and a thread edge c in sequence. Through the combination mode of the thread edge and the second shear tooth, and the change of the clearance of the thread edge, the turnover at various angles is realized, so that the mixing of the materials is more sufficient;

[0053] Compression section b219: Further compact the material in the compression section after the mixing section. After mixing, the material may still be relatively loose. The compression section applies pressure to the material through the action of components such as the screw, compresses it, makes the material more dense, and discharges the air in the material;

[0054] Exhaust section b220: Exhaust the material again;

[0055] Extrusion section 221: Convey and boost the pressure of the material, build a certain pressure, make the material at the die opening have a certain density, and further mix at the same time, and finally achieve the purpose of smoothly extruding and granulating.

[0056] Further, as Figure 11 shown, the structures of the first screw 29 and the second screw 210 are the same, both are small conical screws, the diameter of which gradually decreases along the material conveying direction, the diameter of the end far from the discharge port 212 is D1, the diameter of the end close to the discharge port 212 is D2, the length is L, the taper angle is α, tanα = (D1 - D2) / 2 / L, tanα is 0.001 - 0.009, and the length-diameter ratio is A, A = L / D2, A is 30 - 40.

[0057] Furthermore, for ordinary conical twin screws, the conical screws are generally designed according to the ratio of the large and small head diameters of 2:1, and the length-diameter ratio A is adjusted within the range of 20 - 23. Taking the conical twin-screw barrel with a diameter of 65 / 132, which is widely used in the market, as an example, the effective length of the screw is 1420 mm, the large head diameter is 132 mm, the small head diameter is 65 mm, and the length-diameter ratio is 1420 / 65, approximately equal to 22 times, and tanα = (132 - 65) / 2 / 1420 = 0.0236. However, for the first screw 29 and the second screw 210 of the present invention, their dimensions can reach a diameter of 145 / 192, a length of 5588 mm, a large head diameter of 192 mm, a small head diameter of 145 mm, a length-diameter ratio of 5588 / 145 exceeding 38 times, and tanα = (192 - 145) / 2 / 5588 ≈ 0.0042. From the above data, it can be seen that the first screw 29 and the second screw 210 of the present invention are small taper and extra-long diameter screws, and their advantages are as follows:

[0058] The first small taper: Compared with parallel twin-screw barrels, the working pressure of the inner cavity of the conical twin-screw barrel is higher, which can significantly improve the working efficiency of the plastic extruder. Ordinary conical twin-screw barrels have a relatively large cone angle, and the screw speed is highly sensitive to the pressure in the barrel cavity. The small taper of the present invention is that the screw speed is relatively less sensitive to the pressure in the barrel cavity, which is more conducive to accurately adjusting the working pressure in the barrel cavity by adjusting the screw speed. The speed adjustment range is relatively larger. According to the performance of the processed raw materials, different extrusion products can be processed by setting different speeds in a targeted manner, and the types of raw materials that can be selected are more diverse. At the same time, since the working pressure in the barrel cavity can be accurately adjusted, it is beneficial to improve the quality of the products processed by the plastic extruder.

[0059] The second extra-long diameter: the working length of the screw in the barrel is extended, the component structure is optimized, and the mixing is more sufficient. Since the screw stroke is lengthened, more blending areas can be arranged. During the processing of PET and calcium powder mixed products, a large amount of air will be mixed. In order to reduce the air content in the product, an exhaust section can be reasonably set in the lengthened barrel. The present invention can exhaust the gas in time by setting two exhaust sections, so that the raw materials are mixed more fully and the extrusion is smoother, because the gas will occupy a certain space and affect the full mixing of the materials.

[0060] Example 3

[0061] like Figures 6 - 10 As shown, the difference from the above embodiment is that the auxiliary mechanism 3 also includes a first accommodating slot 31, a plurality of first accommodating slots 31 are opened in the barrel 28, the first accommodating slots 31 are symmetrically distributed on both sides of the exhaust port 211, the first accommodating slots 31 are adjacent to the exhaust port 211, the shape of the first accommodating slot 31 is the same as the shape of the inner wall of the barrel 28, a first annular rail 32 is fixedly installed in the first accommodating slot 31, the shape of the first annular rail 32 is the same as the shape of the first accommodating slot 31, the size of the first annular rail 32 is matched with the size of the first accommodating slot 31, the first annular rail 32 and the barrel 28 are sealed, a moving part 33 is movably installed on the first annular rail 32, the shape of the moving part 33 is the same as the first annular rail 32, the moving part 33 passes through the wall of the first annular rail 32, and the moving part 33 and the first annular rail 32 are sealed.

[0062] Furthermore, a toothed belt 35 is fixedly mounted on the outer ring of the movable member 33. The shape of the toothed belt 35 is the same as that of the movable member 33. The toothed belt 35 passes through the barrel bracket 22. A plurality of auxiliary gears 36 are rotatably mounted on the barrel bracket 22. The auxiliary gears 36 are meshed with the toothed belt 35. A first traction wheel 37 is fixedly mounted on the shaft of the auxiliary gear 36.

[0063] Further, a servo motor 38 is fixedly installed on the base 1. The servo motor 38 is located inside the machine cover plate 21. A second traction wheel 39 is fixedly installed on the shaft of the servo motor 38. A belt 310 is tensioned between the second traction wheel 39 and the first traction wheel 37.

[0064] Further, a second accommodation notch 311 is formed in the barrel 28. The shape of the second accommodation notch 311 is the same as the shape of the inner wall of the barrel 28. A second annular rail 312 is fixedly installed on the second accommodation notch 311. The shape of the second annular rail 312 is the same as the shape of the second accommodation notch 311. A protective collar 313 is movably installed on the inner ring of the second annular rail 312. The shape of the protective collar 313 is the same as the shape of the second annular rail 312. A plurality of ball screws 314 are provided between the protective collar 313 and the second annular rail 312. The ball screws 314 are evenly distributed between the protective collar 313 and the second annular rail 312.

[0065] Among them, when assisting the material to exhaust, the servo motor 38 is started. The servo motor 38 drives the second traction wheel 39 to rotate. The second traction wheel 39 drives the belt 310 to rotate. The belt 310 drives the first traction wheel 37 to rotate. The first traction wheel 37 drives the auxiliary gear 36 to rotate. The auxiliary gear 36 drives the toothed belt 35 to move. The toothed belt 35 drives the moving part 33 to move on the first annular rail 32. The moving part 33 drives the lever 34 to move, so that the lever 34 stirs the material; at the same time, as the first screw 29 rotates relative to the second screw 210, when the first screw 29 or the second screw 210 touches the protective collar 313, the first screw 29 or the second screw 210 drives the protective collar 313 to move on the second annular rail 312, so that the first screw 29 and the second screw 210 will not generate a large amount of friction with the inner wall of the barrel 28, and the ball screws 314 reduce the friction between the protective collar 313 and the second annular rail 312.

[0066] Further, according to production needs, the set length of some extruders will span the entire production workshop. A large amount of air bubbles will accumulate inside the longer barrel 28, resulting in a relatively large internal air pressure in the barrel 28. Therefore, additional settings for the auxiliary mechanism 3 are required on larger extruders.

[0067] Specifically, an extended cavity is provided on the barrel 28. The extended cavity of the barrel 28 and the barrel 28 are of an integral structure, that is, they are cast into an integral rigid part using a mold. The auxiliary gear 36, the first traction wheel 37, the servo motor 38, the second traction wheel 39, and the belt 310 in the auxiliary mechanism 3 are all arranged in the extended cavity of the barrel 28. The first annular rail 32 and the moving part 33 separate the inside of the barrel 28 from the extended cavity of the barrel 28, so that the setting of the auxiliary mechanism 3 is entirely inside the structure of the barrel 28, thereby preventing the barrel 28 from bursting due to the relatively high air pressure inside the barrel 28.

[0068] Furthermore, due to the pressure difference between the interior of the barrel 28 and the extended cavity of the barrel 28, a plurality of triangular stabilizing frames made of rigid materials are arranged in the extended cavity of the barrel 28. The triangular stabilizing frames are evenly distributed beside the first annular rail 32. Rotating wheels are arranged on each triangular stabilizing frame. The rotating wheels are in contact with the moving member 33, so that the rotating wheels provide auxiliary support for the moving member 33 made of soft material. At the same time, a pressure detector is arranged on a single rotating wheel. The detection end of the pressure detector is in contact with the moving member 33. A high-pressure gas tank and an air pump are arranged in the extended cavity of the barrel 28. When the pressure detector detects that the moving member 33 starts to deform under pressure, the air pump will synchronously release gas to balance the air pressure difference between the interior of the barrel 28 and the extended cavity of the barrel 28, so as to maintain the pressure balance between the interior of the barrel 28 and the extended cavity of the barrel 28.

[0069] Furthermore, the method of maintaining the integrity of the overall structure of the barrel 28 and the pressure balance between the interior of the barrel 28 and the extended cavity of the barrel 28 by the pressure in the extended cavity of the barrel 28 are both prior arts, and need to be selectively set according to the size of the extruder equipment. And the setting of the extended cavity of the barrel 28 has no substantial impact on the improvement of the present invention, so it will not be elaborated here.

[0070] The working principle of the whole extruder:

[0071] First, the material is fed into one end of the barrel 28, and the material is conveyed forward by the interior of the barrel 28. The heater 24 is started, and the heater 24 heats the interior of the barrel 28, so that the material melts inside the barrel 28. Then the melted material is extruded from the other end of the barrel 28. At the same time, the moving member 33 is driven to move, so that the moving member 33 moves in an "8" - shaped trajectory inside the barrel 28. The moving member 33 drives the lever 34 to move, so that the lever 34 flips the material inside the barrel 28, thereby assisting the material to flip in the exhaust area to help the bubbles in the material escape, thus forming a stirring action on the melted material inside the barrel, making the melted material flip at the position of the exhaust port to assist the melted material in exhausting gas. In this way, the exhaust efficiency is improved during a specific exhaust time period, the bubble content in the melted material is reduced, the influence of bubbles on the extrusion molding of the material is avoided, and the production quality of the extruder is improved.

[0072] When exhausting auxiliary materials, the servo motor 38 is started. The servo motor 38 drives the second traction wheel 39 to rotate. The second traction wheel 39 drives the belt 310 to rotate. The belt 310 drives the first traction wheel 37 to rotate. The first traction wheel 37 drives the auxiliary gear 36 to rotate. The auxiliary gear 36 drives the toothed belt 35 to move. The toothed belt 35 drives the moving part 33 to move on the first annular rail 32. The moving part 33 drives the lever 34 to move, so that the lever 34 stirs the materials; at the same time, with the rotation of the first screw 29 and the second screw 210, when the first screw 29 or the second screw 210 touches the protective sleeve ring 313, the first screw 29 or the second screw 210 drives the protective sleeve ring 313 to move on the second annular rail 312, so that the first screw 29 and the second screw 210 will not generate a large amount of friction with the inner wall of the barrel 28, and the ball screw 314 reduces the friction between the protective sleeve ring 313 and the second annular rail 312.

[0073] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ultra-long small-taper twin-barrel screw extruder for plastic recycling, comprising a base (1), an extrusion mechanism (2) arranged on the base (1), and an auxiliary mechanism (3) arranged on the extrusion mechanism (2), characterized in that: The extrusion mechanism (2) comprises a machine cover plate (21), a heater (24), and a barrel (28); the machine cover plate (21) is fixedly mounted on the base (1); a barrel support (22) is arranged inside the machine cover plate (21); the heater (24) is fixedly mounted on the base (1); the heater (24) is used to perform a melting process on the material; the barrel (28) is arranged on the base (1); the barrel (28) passes through a heating area of ​​the heater (24); and the barrel (28) is used to transport and process the material; The auxiliary mechanism (3) comprises a moving part (33) and a lever (34); the moving part (33) is movably arranged in the barrel (28); the moving part (33) is located in the exhaust area of ​​the extruder; the shape of the moving part (33) is adapted to the shape of the inner wall of the barrel (28); a plurality of levers (34) are fixedly mounted on the inner ring wall surface of the moving part (33); the levers (34) are evenly distributed on the moving part (33); the length of the levers (34) is adapted to the length of the exhaust area of ​​the extruder; and the levers (34) move synchronously with the moving part (33); The auxiliary mechanism (3) further comprises a first accommodating notch (31), a plurality of the first accommodating notches (31) are provided in the barrel (28), a first annular rail (32) is fixedly mounted in the first accommodating notch (31), and the moving member (33) is movably mounted on the first annular rail (32); A toothed belt (35) is fixedly mounted on the outer ring of the moving member (33); a plurality of auxiliary gears (36) are rotatably mounted on the barrel support (22); and a first traction wheel (37) is fixedly mounted on the shaft of the auxiliary gear (36); A servo motor (38) is fixedly mounted on the base (1), the servo motor (38) is located inside the machine cover plate (21), a second traction wheel (39) is fixedly mounted on the shaft of the servo motor (38), and a belt (310) is tensioned between the second traction wheel (39) and the first traction wheel (37); A first screw (29) is arranged in the barrel (28), a second screw (210) is arranged in the barrel (28), a discharge port (212) is fixedly mounted at one end of the barrel (28), the first screw (29) and the second screw (210) have the same structure, both are small conical screws, the diameter of which gradually decreases along the material conveying direction, the diameter of the end away from the discharge port (212) is D1, the diameter of the end close to the discharge port (212) is D2, the length is L, the cone angle is α, tanα=(D1-D2) / 2 / L, tanα is 0.001-0.009, the aspect ratio is A, A=L / D2, A is 30-40.

2. The ultra-long small-taper twin-barrel screw extruder for plastic recycling according to claim 1, characterized in that: The barrel bracket (22) is fixedly mounted on the base (1), the barrel bracket (22) passes through both ends of the machine cover plate (21), a feed hopper (23) is fixedly mounted on the machine cover plate (21), the bottom end of the feed hopper (23) passes through the wall surface of the machine cover plate (21), the bottom end of the feed hopper (23) passes through the barrel bracket (22), the bottom end of the feed hopper (23) is connected to the barrel (28), and the barrel (28) passes through the heating area of ​​the heater (24).

3. The ultra-long small-taper twin-barrel screw extruder for plastic recycling according to claim 2, characterized in that: A main motor (25) is fixedly mounted on the base (1), a coupling (26) is fixedly mounted on the shaft of the main motor (25), a gear set (27) is arranged on the base (1), one end of the gear set (27) is connected to the coupling (26) by power, the other end of the gear set (27) extends into the barrel (28), the first screw (29) and the second screw (210) are thread-matched, the gear set (27) is connected to the first screw (29) by power, and the gear set (27) is connected to the second screw (210) by power, so that the first screw (29) and the second screw (210) rotate relative to each other.

4. The ultra-long small-taper twin-barrel screw extruder for plastic recycling according to claim 3, characterized in that: The barrel (28) is provided with a plurality of exhaust ports (211), the exhaust ports (211) being located in an exhaust area of ​​the extruder, the exhaust ports (211) being communicated with the interior of the machine cover plate (21), the discharge ports (212) being communicated with the barrel (28), the discharge ports (212) penetrating the barrel support (22), and the discharge ports (212) penetrating the machine cover plate (21).

5. The ultra-long small-taper twin-barrel screw extruder for plastic recycling according to claim 4, characterized in that: The barrel (28) comprises a plurality of regions therein. A feeding section (213) is provided at one end of the barrel (28). The feeding section (213) is used to transport materials. A pre-plasticizing section (214) is provided inside the barrel (28). The pre-plasticizing section (214) is adjacent to the feeding section (213). The pre-plasticizing section (214) is used to heat and soften the materials. A mixing section a (215) is provided inside the barrel (28). The mixing section a (215) is adjacent to the pre-plasticizing section (214). The mixing section a (215) is used to mix and shear the materials. The barrel (28) is provided with a compression section a (216) inside, the compression section a (216) is adjacent to the mixing section a (215), the compression section a (216) is used to compact the material, the barrel (28) is provided with an exhaust section a (217) inside, the exhaust section a (217) is adjacent to the compression section a (216), the exhaust section a (217) is used to exhaust the material, the barrel (28) is provided with a mixing section b (218) inside, the mixing section b (218) is adjacent to the exhaust section a (217), the mixing section b (218) is used to again The material is mixed and sheared, a compression section b (219) is provided inside the barrel (28), the compression section b (219) is adjacent to the mixing section b (218), the compression section b (219) is used to compact the material again, a venting section b (220) is provided inside the barrel (28), the venting section b (220) is adjacent to the compression section b (219), the venting section b (220) is used to vent the material again, an extrusion section (221) is provided inside the barrel (28), the extrusion section (221) is adjacent to the venting section b (220), the extrusion section The section (221) is used for extruding materials. The first screw (29) and the second screw (210) are both fixed with a plurality of first shearing teeth with a tooth shape at the mixing section a (215). The first shearing teeth on the first screw (29) and the second screw (210) are meshed with each other. The first screw (29) and the second screw (210) are both fixed with screw ridge a, second shearing teeth with a tooth shape, screw ridge b and screw ridge c in sequence at the mixing section b (218). The second shearing teeth on the first screw (29) and the second screw (210) are meshed with each other.

6. The ultra-long small-taper twin-barrel screw extruder for plastic recycling according to claim 5, characterized in that: The first accommodating notches (31) are symmetrically distributed on both sides of the exhaust port (211), the first accommodating notches (31) are adjacent to the exhaust port (211), the shape of the first accommodating notches (31) is the same as the shape of the inner wall of the barrel (28), the shape of the first annular rail (32) is the same as the shape of the first accommodating notches (31), the size of the first annular rail (32) is matched with the size of the first accommodating notches (31), the first annular rail (32) and the barrel (28) are sealed, the shape of the moving member (33) is the same as the first annular rail (32), the moving member (33) passes through the wall of the first annular rail (32), and the moving member (33) and the first annular rail (32) are sealed.

7. The ultra-long small-taper twin-barrel screw extruder for plastic recycling according to claim 6, characterized in that: The shape of the toothed belt (35) is the same as that of the moving member (33); the toothed belt (35) passes through the barrel bracket (22); and the auxiliary gear (36) is meshed with the toothed belt (35).

8. The ultra-long small-taper twin-barrel screw extruder for plastic recycling according to claim 7, characterized in that: A second accommodating notch (311) is provided in the barrel (28), the shape of the second accommodating notch (311) being the same as the shape of the inner wall of the barrel (28), a second annular rail (312) being fixedly mounted on the second accommodating notch (311), the shape of the second annular rail (312) being the same as the shape of the second accommodating notch (311), a protective collar (313) being movably mounted on the inner ring of the second annular rail (312), the shape of the protective collar (313) being the same as the shape of the second annular rail (312), a plurality of ball rods (314) being provided between the protective collar (313) and the second annular rail (312), the ball rods (314) being evenly distributed between the protective collar (313) and the second annular rail (312).

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