Double-screw extruder for producing plastic particles

Abstract

The utility model relates to the technical field of extruders, and discloses a twin-screw extruder for plastic particle production, which comprises an extruder shell, two extrusion screws symmetrically penetrate through and are rotatably connected to the left side surface of the extruder shell in the front-back direction, and gears are fixedly sleeved at the left ends of the exteriors of the extrusion screws. A driving mechanism is arranged at the rear end of the left side surface of the extruder shell, and a feeding bin communicated with the interior of the extruder shell is fixedly connected to the left end of the upper surface of the extruder shell; an impurity removal mechanism is arranged on the surface of the left side of the feeding bin; by arranging the vibrating screen plate and the elastic supporting structure, large-particle impurities in plastic raw materials can be effectively separated, and it is ensured that only the raw materials meeting the particle size requirement enter the extrusion process; the negative pressure adsorption principle is used for regularly removing impurities retained on the screen surface, impurity pumping and discharging operation can be automatically completed in the state of not stopping for a long time, the screen surface self-cleaning function is achieved, and the stability of continuous production of equipment and the impurity removing accuracy are further improved.

Description

Technical Field

[0001] This utility model relates to the field of extruder technology, specifically a twin-screw extruder for producing plastic particles. Background Technology

[0002] A twin-screw extruder for plastic particles is a device used to heat, melt, compress, and extrude plastic particles. It consists of two rotating screw shafts. Through the rotation of the screw shafts and the heating of an external heating system, the plastic particles are heated to a molten state and then extruded through the die of the extruder. Twin-screw extruders for plastic particles are widely used in the production of plastic products, such as plastic pipes, sheets, films, and cables. They have the advantages of high production efficiency, simple operation, and good molding quality.

[0003] However, existing twin-screw extruders often lack a structure that can screen the feed, which often causes blockages when larger particles of raw materials, sand, or metal are mixed with the feed material and enter the machine. This also causes significant wear and tear on the machine and affects its service life.

[0004] Chinese patent discloses an anti-clogging twin-screw extruder for plastic particles (authorization announcement number CN221437171U). This patented technology utilizes a vibrating motor, activated by an external power supply, to drive the screen plate and screen mesh to vibrate, achieving material screening and mixing. This improves screening efficiency and mixing uniformity. The screen plate and screen mesh arrangement ensures that the vibration from the central vibrating motor is evenly transmitted to the surrounding area, resulting in uniform vibration of the screen plate and screen mesh. This allows for more thorough screening of the raw materials, ensuring product quality. The technology also incorporates damping springs... The sliding rod and insertion hole settings allow the damping springs above and below the fixed plate to slow down and absorb vibrations when the screen plate vibrates to the edge, preventing vibrations from being transmitted to the feed hopper and maintaining the stability of the feed. The upper and lower limit plates can effectively control the vibration amplitude of the screen plate, preventing excessive vibrations from causing raw materials to spill out of the feed hopper and damaging the machine body. This device can screen larger impurities and raw material particles, preventing them from clogging the machine, improving the working efficiency and product quality of the extruder, while protecting the machine body from damage and ensuring the stability and safety of the production process.

[0005] However, it has certain drawbacks: operators need to frequently pause the production process, manually operate the dust collection equipment and adjust the position of the dust collection port to suck up impurities from the screen surface. During this process, the positioning accuracy of the dust collection port depends on manual judgment, and impurities are easily left behind due to operational deviations. Furthermore, the timeliness of manual intervention is difficult to guarantee. Since the cleaning operation relies on manual inspection to judge the amount of impurities accumulated, if it is not handled in time, the risk of screen blockage will increase and the flow of raw materials will be obstructed. Utility Model Content

[0006] The purpose of this invention is to provide a twin-screw extruder for the production of plastic particles, in order to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A twin-screw extruder for producing plastic particles includes an extruder housing. Multiple heating plates are embedded and fixedly connected to the inner surface of the extruder housing from left to right. Two extrusion screws are symmetrically and rotatably connected through the left side surface of the extruder housing. Gears are fixedly sleeved on the outer left end of each extrusion screw. A drive mechanism is provided at the rear end of the left side surface of the extruder housing. An extrusion die is fixedly connected to the right side surface of the extruder housing and communicates with its interior. A feed hopper is fixedly connected to the left end of the upper surface of the extruder housing and communicates with its interior. A screen plate is movably connected inside the feed hopper. A vibration motor is fixedly connected to the lower surface of the screen plate. Slide rods are movably connected through the four corners of the screen plate. Fixed blocks are fixed to the upper and lower ends of each slide rod, and springs are movably sleeved on the upper and lower sides of the slide rods located on the screen plate.

[0009] The left side surface of the feed hopper is provided with a cleaning mechanism, which includes a centrifugal fan. The air inlet end of the centrifugal fan is fixedly connected to a main pipe, and the right end of the main pipe is fixedly connected to an air box. The right side surface of the air box is fixedly connected to multiple branch pipes that communicate with its interior from front to back, and the upper surface of the air box is provided with an opening and closing mechanism.

[0010] As a further improvement of this utility model: the driving mechanism includes an L-shaped plate, and a motor is fixedly connected to the left side surface of the L-shaped plate.

[0011] As a further embodiment of this utility model: the opening and closing mechanism includes an L-shaped plate II, a telescopic cylinder is fixedly connected to the upper surface of the L-shaped plate II, and an opening and closing plate is fixedly connected to the telescopic end of the telescopic cylinder.

[0012] As a further embodiment of this utility model: the heating plate and the inner surface of the extruder housing are flush, the two gears mesh with each other, the right end of the extrusion screw is directly opposite the extrusion die, the fixing block is fixed to the inner side surface of the feed hopper, one end of the spring is fixed to the screen plate, and the other end of the spring is fixed to the fixing block, the main pipe is connected to the inside of the air box, the right end of the branch pipe is fixed to the left side surface of the feed hopper, and the branch pipe is connected to the inside of the feed hopper.

[0013] As a further embodiment of this utility model: the L-shaped plate is fixedly connected to the left side surface of the extruder housing, and the output end of the motor is fixedly connected to the left end of the rear extrusion screw.

[0014] As a further embodiment of this utility model: the L-shaped plate is fixedly connected to the upper surface of the air box, the opening and closing plate moves through the upper surface of the air box, and the opening and closing plate moves to fit against the inner right side surface of the air box.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. This utility model, by setting up a vibrating screen plate and an elastic support structure, can effectively separate large particulate impurities in plastic raw materials, ensuring that only raw materials that meet the particle size requirements enter the extrusion process. Its vibration combined with the elastic buffer design improves the screening efficiency and ensures the molding quality and consistency of plastic particles.

[0017] 2. This utility model uses a cleaning mechanism to remove impurities retained on the screen surface at regular intervals by utilizing the principle of negative pressure adsorption. The mechanism adopts a multi-branch air duct layout and an opening and closing control design, which can automatically complete the impurity extraction operation without long-term machine downtime. This not only realizes the self-cleaning function of the screen surface, but also significantly improves the stability of continuous production and the accuracy of impurity removal. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a twin-screw extruder for producing plastic particles.

[0019] Figure 2 A cross-sectional view of a heating plate in a twin-screw extruder for producing plastic pellets;

[0020] Figure 3 This is a schematic diagram of the extrusion screw in a twin-screw extruder used for plastic particle production.

[0021] Figure 4 for Figure 1 Enlarged view of A in the middle;

[0022] Figure 5 A cross-sectional view of the feed hopper in a twin-screw extruder for producing plastic pellets;

[0023] Figure 6 This is a schematic diagram of the impurity removal mechanism in a twin-screw extruder used for plastic particle production.

[0024] In the diagram: 1. Extruder housing; 2. Heating plate; 3. Extrusion screw; 4. Gear; 5. Drive mechanism; 6. L-shaped plate one; 7. Motor; 8. Extrusion die; 9. Feed hopper; 10. Screen plate; 11. Vibrating motor; 12. Slide rod; 13. Fixing block; 14. Spring; 15. Impurity removal mechanism; 16. Centrifugal fan; 17. Main pipe; 18. Air box; 19. Branch pipe; 20. Opening and closing mechanism; 21. L-shaped plate two; 22. Telescopic cylinder; 23. Opening and closing plate. Detailed Implementation

[0025] Please see Figures 1-4 In this embodiment of the present invention, a twin-screw extruder for producing plastic particles includes an extruder housing 1. Multiple heating plates 2 are embedded and fixedly connected from left to right on the inner surface of the extruder housing 1. The heating plates 2 are flush with the inner surface of the extruder housing 1. Two extrusion screws 3 are symmetrically and rotatably connected through the left side surface of the extruder housing 1. Gears 4 are fixedly sleeved on the outer left end of the extrusion screws 3. The two gears 4 mesh with each other. A drive mechanism 5 is provided at the rear end of the left side surface of the extruder housing 1. The drive mechanism 5 includes an L-shaped plate 6. The L-shaped plate 6 is fixedly connected to the left side surface of the extruder housing 1. A motor 7 is fixedly connected to the left side surface of the L-shaped plate 6. The output end of the motor 7 is fixedly connected to the left end of the rear extrusion screw 3. An extrusion die 8 communicating with the inside is fixedly connected to the right side surface of the extruder housing 1. The right end of the extrusion screw 3 is directly opposite the extrusion die 8. A feed hopper 9 communicating with the inside is fixedly connected to the left end of the upper surface of the extruder housing 1.

[0026] The heating plate 2 includes a plate body and an electric heating wire fixed inside the plate body. The plate body is preferably made of stainless steel (such as 304 or 316L).

[0027] The motor 7 is used to drive the rear extrusion screw 3 to rotate. Under the action of the two gears 4, the other extrusion screw 3 will also rotate, thereby extruding plastic.

[0028] Feed hopper 9 is used for discharging plastic particle raw materials.

[0029] exist Figure 1 and Figure 5 In the middle: a screen plate 10 is movably connected inside the feed hopper 9. A vibrating motor 11 is fixedly connected to the lower surface of the screen plate 10. Slide rods 12 are movably connected to the four corners of the screen plate 10. Fixed blocks 13 are fixedly connected to the upper and lower ends of the slide rods 12. The fixed blocks 13 are fixedly connected to one side of the inner surface of the feed hopper 9. Springs 14 are movably sleeved on the upper and lower sides of the slide rods 12 located outside the screen plate 10. One end of the spring 14 is fixedly connected to the screen plate 10, and the other end of the spring 14 is fixedly connected to the fixed block 13.

[0030] The sieve plate 10 is used to screen plastic particle raw materials, blocking larger particles and impurities to prevent them from affecting the production quality of plastic particles.

[0031] The vibrating motor 11 is used to drive the screen plate 10 to vibrate, thereby improving the screening efficiency.

[0032] exist Figure 1 , Figure 5 and Figure 6In the middle: A cleaning mechanism 15 is provided on the left side surface of the feeding hopper 9. The cleaning mechanism 15 includes a centrifugal fan 16. The air inlet end of the centrifugal fan 16 is fixedly connected to a main pipe 17. The right end of the main pipe 17 is fixedly connected to an air box 18. The main pipe 17 is connected to the inside of the air box 18. Multiple branch pipes 19 connected to the inside of the air box 18 are fixedly connected from front to back on the right side surface of the air box 18. The right end of the branch pipes 19 is fixedly connected to the left side surface of the feeding hopper 9 and is connected to the inside of the feeding hopper 9. An opening and closing mechanism 20 is provided on the upper surface of the air box 18. The opening and closing mechanism 20 includes an L-shaped plate 21. The L-shaped plate 21 is fixedly connected to the upper surface of the air box 18. A telescopic cylinder 22 is fixedly connected to the upper surface of the L-shaped plate 21. An opening and closing plate 23 is fixedly connected to the telescopic end of the telescopic cylinder 22. The opening and closing plate 23 moves through the upper surface of the air box 18 and moves against the inner right side surface of the air box 18.

[0033] Centrifugal fan 16 is a commonly used conveying equipment in industry. It belongs to the category of industrial-grade centrifugal fans (refer to GB / T3235-2008 "Technical Conditions for Centrifugal Fans"). It uses mechanical seals or labyrinth seals between the drive motor and the impeller cavity to ensure that foreign objects cannot enter the motor cavity in reverse when rotating at high speed. Therefore, no damage or other problems will occur when sucking up foreign objects.

[0034] The centrifugal fan 16 preferably has a frequency conversion function, which can adjust the power, that is, adjust the suction force, so that the suction force is sufficient to draw out raw materials and impurities with larger particles.

[0035] A protective net is installed at the air outlet of the centrifugal fan 16 to prevent people from touching the impeller and to allow the discharge of larger particles of raw materials and impurities; a collection net can be installed at the air outlet.

[0036] Branch pipe 19 is flush with the upper surface of screen plate 10. Under the action of centrifugal fan 16, it sucks out the accumulated raw materials and impurities with larger particles to avoid excessive accumulation and affecting screening (during the suction process, the material discharge is briefly stopped).

[0037] The right end of branch pipe 19 is tilted downwards to prevent raw materials from entering branch pipe 19 during normal screening.

[0038] The telescopic cylinder 22 is preferably a pneumatic cylinder, and its initial state is the extended state, at which time the opening and closing plate 23 is located in the air box 18;

[0039] When not pumping out raw materials and impurities with larger particles, the opening and closing plate 23 extends into the air box 18; when pumping out raw materials and impurities with larger particles, the telescopic cylinder 22 retracts, causing the opening and closing plate 23 to move upward away from the air box 18 (the lower end of the opening and closing plate 23 is still located inside the upper end of the air box 18).

[0040] Both the centrifugal fan 16 and the telescopic cylinder 22 are connected to an external control system for automated operation.

[0041] The working principle of this utility model is as follows: After the plastic particle raw material is fed into the feeding hopper 9, the vibrating motor 11 drives the screen plate 10 to vibrate and screen along the slide bar 12. The qualified raw material falls into the extruder housing 1, while the larger particles and impurities remain on the upper surface of the screen plate 10. The heating plate 2 heats and melts the raw material, and the motor 7 drives the twin screw to rotate and propel the melt through the gear 4. The melt is formed through the extrusion die 8. Feeding is paused every once in a while, the telescopic cylinder 22 retracts the opening and closing plate 23 and opens the air box 18. The centrifugal fan 16 sucks up the impurities accumulated on the screen plate 10 through the main pipe 17, the air box 18 and the branch pipe 19. After the impurity removal is completed, the opening and closing plate 23 is reset, and feeding is resumed to continue production.

[0042] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.

[0043] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. A double screw extruder for plastic particle production, comprising an extruder shell (1), the inner surface of the extruder shell (1) is embedded with a plurality of heating plates (2) from left to right, and two extrusion screws (3) are rotatably connected through the left surface of the extruder shell (1) in a front-to-back direction symmetry, the outer left end of the extrusion screw (3) is fixedly sleeved with a gear (4), the left surface of the extruder shell (1) is provided with a driving mechanism (5) at the rear end, and the right surface of the extruder shell (1) is fixedly connected with an extrusion die (8) communicating with the inside thereof, the left end of the upper surface of the extruder shell (1) is fixedly connected with a feeding bin (9) communicating with the inside thereof, the inside of the feeding bin (9) is movably connected with a sieve plate (10), the lower surface of the sieve plate (10) is fixedly connected with a vibration motor (11), and the four corners of the sieve plate (10) are movably connected with a slide rod (12), the upper and lower ends of the slide rod (12) are fixedly connected with a fixed block (13), and the outside of the slide rod (12) is movably sleeved with a spring (14) on the upper and lower sides of the sieve plate (10). characterized in that The left surface of the feeding bin (9) is provided with a impurity removal mechanism (15), the impurity removal mechanism (15) comprises a centrifugal fan (16), the air inlet end of the centrifugal fan (16) is fixedly connected with a main pipe (17), the right end of the main pipe (17) is fixedly connected with a wind box (18), the right surface of the wind box (18) is fixedly connected with a plurality of branch pipes (19) communicating with the inside thereof from front to back, and the upper surface of the wind box (18) is provided with an opening and closing mechanism (20).

2. The twin-screw extruder for plastic particle production according to claim 1, wherein The driving mechanism (5) comprises an L-shaped plate one (6), and the left surface of the L-shaped plate one (6) is fixedly connected with a motor (7).

3. The twin-screw extruder for plastic particle production according to claim 1, wherein The opening and closing mechanism (20) comprises an L-shaped plate two (21), the upper surface of the L-shaped plate two (21) is fixedly connected with a telescopic cylinder (22), and the telescopic end of the telescopic cylinder (22) is fixedly connected with an opening and closing plate (23).

4. The twin-screw extruder for plastic particle production according to claim 1, wherein The heating plate (2) is flush with the inner surface of the extruder shell (1), the two gears (4) are meshed with each other, the right end of the extrusion screw (3) is opposite to the extrusion die (8), the fixed block (13) is fixedly connected to one side surface in the inside of the feeding bin (9), one end of the spring (14) is fixedly connected to the sieve plate (10), and the other end of the spring (14) is fixedly connected to the fixed block (13), the main pipe (17) communicates with the inside of the wind box (18), the right end of the branch pipe (19) is fixedly connected to the left surface of the feeding bin (9), and the branch pipe (19) communicates with the inside of the feeding bin (9).

5. The twin-screw extruder for plastic particle production according to claim 2, wherein The L-shaped plate one (6) is fixedly connected to the left surface of the extruder shell (1), and the output end of the motor (7) is fixedly connected to the left end of the rear extrusion screw (3).

6. The twin-screw extruder for plastic particle production according to claim 3, wherein The L-shaped plate two (21) is fixedly connected to the upper surface of the wind box (18), the opening and closing plate (23) movably penetrates the upper surface of the wind box (18), and the opening and closing plate (23) movably adheres to the right inner surface of the wind box (18).

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