A plastic pelletizing apparatus

Abstract

The application discloses a plastic granulating device, which comprises a die head, a plurality of knife sets with rotating function and a moving block, wherein the die head is provided with a plurality of discharge ports arranged in a ring array; each of the knife sets is provided with a plurality of cutters, each of the cutters is provided with a receiving cavity capable of contacting the cutting surface of the discharge port, and a moving block with reciprocating motion is arranged above the receiving cavity; a rolling cavity is formed in the moving block, and a channel capable of passing through a spherical body is formed between the rolling cavity and the receiving cavity during the reciprocating motion of the rolling cavity and the receiving cavity, and the cross section of the channel is not greater than that of the discharge port. The application has the advantages that the molten line after being extruded from the die head is cut to form molten line particles, the molten line particles are pushed to roll and spin out of the water film for cooling by using the centrifugal force of rotation, and the proportion of the produced plastic particles in spherical shape is high.

Description

Technical Field

[0001] This invention relates to the field of runway granulation technology, specifically to a plastic granulation device. Background Technology

[0002] Plastic granulators are used to process various forms of plastic raw materials through processes such as heating, melting, mixing, extrusion, cooling, and cutting to ultimately produce plastic granules.

[0003] Plastic running track granules need to balance elasticity, wear resistance, and environmental friendliness. The shape requirements for the bottom layer, structural layer, and surface layer of plastic running track granules are different. For the surface layer granules, they need to be nearly spherical and without sharp edges. To meet the above requirements, the corresponding plastic granules can be manufactured using the water ring pelletizing method.

[0004] The cutter of the plastic granulator rotates at high speed on the die head surface, instantly cutting the freshly extruded melt into granules, which are simultaneously cooled and carried away by the water ring. Although the cutter cools the granules after cutting the melt, some granules still exhibit irregularities. For high-performance granules used in plastic running track surface layers, the resulting granules need to be screened to select near-spherical granules. Therefore, the utilization rate of granules produced for running track surface layers is not high.

[0005] In view of this, we propose a plastic granulation device. Summary of the Invention

[0006] The purpose of this invention is to provide a plastic granulation device to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a plastic granulation device, including a die head, wherein the die head is provided with a discharge port arranged in a ring array, and further includes a blade assembly with a rotating function and a moving block;

[0008] The blade assembly is equipped with several blades, each of which has a receiving cavity that can contact the cut surface of the discharge port. Above the receiving cavity is a moving block with reciprocating motion. During the reciprocating motion between the rounding cavity on the moving block and the receiving cavity, a channel for the passage of a sphere can be formed. The cross-section of this channel is not larger than the discharge port.

[0009] The molten material after melting by the granulating device is extruded from the discharge port of the die head, the high-speed rotating cutter cuts the extruded melt line particles, and the cut melt line particles enter the receiving cavity along with the rotation of the cutter. At this time, the moving block guide portion is about to enter the recess of the guide unit, and the moving block guide portion enters the recess of the guide unit due to the centrifugal force of rotation. In this process, the rolling cavity on the moving block first forms a hemispherical cavity with the receiving cavity to cut off the excess part of the melt line particles, and the rolling cavity continues to throw out to push the cut melt line particles along the channel through which the ball communicates with the receiving cavity. The melt line particles rolling along the channel through which the ball passes are rolled into spherical shape. The moving block guide portion contacts the next protruding guide of the guide unit, and the moving block is pushed back to expose the receiving cavity. The cutter rotates to the next discharge port, continues to cut the extruded melt line particles into the receiving cavity, and repeats the above process, and the cut melt line particles maintain a high proportion of spherical shape.

[0010] Preferably, a plurality of shanks are arranged in an annular array on the cutter group, and the cutter is connected to the shank by a bolt. The cutter connecting section is inserted into the groove of the shank, and the bolt passes through the hole on the cutter and the hole on the shank to fix it. The cutter cutting side rotates at high speed on the surface of the die head.

[0011] Preferably, the cutter cutting side along the rotation direction of the cutter group is formed as an inclined surface A, and the cutter cutting side at the inclined surface A is sequentially provided with a spherical cavity A and an arc cavity. The spherical cavity A serves as a receiving cavity, and the arc cavity serves as a channel through which the ball passes.

[0012] The inner wall at the connection between the spherical cavity A and the arc cavity is continuous.

[0013] Preferably, the rolling unit further comprises a fixed strip and a moving block.

[0014] The fixed strip is fixed on the cutter, and the moving block is movably arranged along the cutter. The moving block and the fixed strip are connected by an extension piece.

[0015] The side end of the moving block in the throwing direction is provided with a spherical cavity B, which serves as a rolling cavity.

[0016] Preferably, during the movement of the spherical cavity B along the arc cavity, the melt line particles rolling in the arc cavity are pushed and extruded by the spherical surface of the spherical cavity B to be shaped.

[0017] The melt line particles entering the spherical cavity A are pushed by the moving spherical cavity B into the arc cavity, the melt line particles roll along the arc cavity, and the spherical surface of the spherical cavity B cooperates with the arc cavity to shape the melt line particles into spherical shape.

[0018] Preferably, the moving block corresponding to the spherical cavity B is formed as an inclined surface B, and the inclined surface B contacts the inclined surface A.

[0019] The melt line particles are cut into the spherical cavity A, and the spherical cavity B and the arc cavity form a semi-spherical cavity, and then continue to move, so that the excess part of the melt line particles can be cut off, the cut-off part is pushed by the side surface at the inclined surface B and moves along the inclined surface A, and the cut-off part is thrown out along the inclined surface A.

[0020] Preferably, the guiding unit comprises a connecting ring and a guiding ring;

[0021] The connecting ring is fixed to the extrusion side of the die head through the connecting block, and the guiding ring is fixed to the inner periphery of the connecting ring.

[0022] The side end of the moving block throwing direction is fixed with a guiding rod, and the guiding rod contacts the wavy inner periphery of the guiding ring and reciprocates.

[0023] The guiding rod reciprocates by rising along the inner periphery of the guiding ring during rotation, so that the moving block moves reciprocally along the cutter.

[0024] Preferably, the contact end of the guiding rod and the guiding ring is provided with a spherical surface, so that the resistance is small when the guiding rod and the guiding ring guide.

[0025] Compared with the prior art, the application has the following advantages:

[0026] In the application, the cutter group, the rounding unit and the guiding unit are provided, the melt line after being extruded from the die head is cut to form melt line particles, and the melt line particles are pushed and rounded by the centrifugal force of rotation, so that the melt line particles are formed into spherical shape and thrown out to contact the water film for cooling, the proportion of the produced plastic particles in spherical shape is high, and the problem that although the cross section of the particles after being cut by the cutter is cooled by the water ring, some particles still exist irregularly is solved.

[0027] In the application, the melt line particles are cut into the spherical cavity A, and the spherical cavity B and the arc cavity form a semi-spherical cavity, and then continue to move, so that the excess part of the melt line particles can be cut off, the cut-off part is pushed by the side surface at the inclined surface B and moves along the inclined surface A, and the cut-off part is thrown out along the inclined surface A. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the application;

[0029] Figure 2 It is a schematic diagram of the melt line cutting structure of the application;

[0030] Figure 3 It is a schematic diagram of the melt line cutting structure of the application;

[0031] Figure 4 It is a schematic diagram of the melt line rounding front section structure of the application;

[0032] Figure 5 Schematic diagram of the middle section of the melt line rounding structure of the present application;

[0033] Figure 6 Schematic diagram of the rear section of the melt line rounding structure of the present application;

[0034] Figure 7 Schematic diagram of the connection structure of the rounding unit of the present application;

[0035] Figure 8 Schematic diagram of the guide unit structure of the present application;

[0036] Figure 9 Schematic diagram of the melt line cutting and rounding structure of the present application;

[0037] Figure 10 Schematic diagram of the water ring cooling water channel structure of the present application;

[0038] Figure 11 Schematic diagram of the guide unit structure of the present application.

[0039] In the figure: 100, frame; 200, holder; 300, motor; 400, pelletizing chamber; 500, cutter group; 600, guide unit; 700, water ring cooling water channel; 800, rounding unit; 900, die head;

[0040] 501, cutter handle; 502, cutter;

[0041] 5021, inclined surface A; 5022, spherical cavity A; 5023, arc-shaped cavity;

[0042] 601, connecting ring; 602, guide ring; 603, connecting block;

[0043] 801, fixed strip; 802, moving block; 803, telescopic piece; 804, guide rod;

[0044] 8021, spherical cavity B; 8022, inclined surface B;

[0045] 901, discharge port. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0047] A plastic pelletizing device, please refer to Figures 1 to 3, including a rack 100 for installing a granulating mechanism, a holding frame 200 fixed on the rack 100 for installing a motor 300 and a pelletizing chamber 400, and a water ring cooling water channel 700 arranged in the pelletizing chamber 400 for cooling.

[0048] The granulating mechanism comprises a feeding system, an extruding system, a filtering system, a pelletizer head, a pelletizing device, a dehydration drying system and a control system.

[0049] The feeding system continuously and stably feeds the plastic raw material into the extruding system.

[0050] In the embodiment, the feeding system can adopt a hopper with gravity feeding, a forced feeding screw, a side feeder, etc.

[0051] The extruding system comprises a cylinder and a screw, and the material is subjected to the actions of conveying, compressing, shearing and mixing in the cylinder by the screw, and is melted and plasticized into uniform melt by external heating and self-friction heat.

[0052] In the embodiment, the extruding system can adopt a double screw.

[0053] The filtering system comprises a porous plate and a filter screen, which filter out impurities in the melt to improve the purity of the particles and increase the back pressure of the melt to promote more uniform plasticization and mixing.

[0054] The pelletizer head comprises a head and a die 900.

[0055] The head guides the molten plastic into shape and uniformly distributes it into the die holes.

[0056] The die 900 is drilled with a specific number, diameter and arrangement of discharge ports 901. The melt is extruded through the discharge ports 901 to form plastic strips (strip granulation) or directly form melt lines (underwater / water ring granulation).

[0057] In the embodiment, the die 900 directly forms melt lines for water ring granulation.

[0058] The pelletizing device comprises strip granulation and die face hot pelletization.

[0059] The strip granulation is that the extruded plastic strip is cooled and solidified in a cooling water tank and then pulled to a pelletizer rotating blade to cut into particles.

[0060] The die face hot pelletization comprises water ring pelletization, underwater pelletization and air-cooled die face hot pelletization.

[0061] In the embodiment, the water ring pelletization is that a cutter rotates at high speed on the surface of the die 900 to instantaneously cut off the just-extruded melt line into particles, which are cooled and taken away by the high-speed rotating water ring.

[0062] For the wet particles generated by the water ring, the dehydration drying system is needed to remove the surface moisture.

[0063] In this embodiment, the dewatering and drying system adopts a centrifugal dewatering machine and / or a vibrating screen, a hot air dryer and the like.

[0064] The control system is mainly a PLC or computer control system.

[0065] The above granulating mechanism is installed on the frame 100.

[0066] In this embodiment, the motor 300 can adopt a servo motor, and the power of the motor 300 is controlled by a servo, and the motor 300 drives the rotation of the screw rod of the extrusion system through the transmission wheel set.

[0067] The water ring cooling water channel 700 surrounds the cutting knife area, and the tangential water inlet is arranged on the side wall of the cutting granulating chamber 400. The water flow enters the water ring cooling water channel 700 in a tangential direction, and the water flow forms a high-speed vortex after being injected in a tangential direction, and forms a uniform water film on the inner wall of the cavity of the water ring cooling water channel 700. The contact time of the particles with the water film is ≤0.3 seconds, and the surface temperature is suddenly reduced from 200°C to below 60°C, thereby inhibiting crystallization and deformation.

[0068] Please refer to Figures 2 to 10 , the granulating device includes a knife set 500, a rounding unit 800 and a guide unit 600;

[0069] The melt line extruded from the die head 900 passes through the granulating device, and the melt line extruded from the die head 900 is cut.

[0070] The knife set 500 connected to the output end of the motor 300 rotates at high speed, and the cutter 502 connected to the knife set 500 rotates at high speed on the surface of the die head 900 for cutting the melt line extruded from the granulating mechanism die head 900.

[0071] In this embodiment, the transmission shaft of the motor 300 is connected to the knife set 500 through a shaft coupling.

[0072] In this embodiment, a plurality of knife handles 501 are arranged in an annular array on the knife set 500, and the cutter 502 is connected to the knife handle 501 through bolts. The cutter 502 is inserted into the groove of the knife handle 501, and the bolts pass through the holes on the cutter 502 and the holes on the knife handle 501 to be fixed. The end of the bolt passing through can be installed with a nut. The cutter 502 and the knife handle 501 can be assembled or disassembled.

[0073] The cutter 502 is sequentially provided with a spherical cavity A5022 and an arc-shaped cavity 5023 on the cutting side. The spherical cavity A5022 contains the cut melt line particles.

[0074] The rolling unit 800 comprises a fixed strip 801 and a moving block 802; the fixed strip 801 is fixed on the cutter 502, and the moving block 802 is movably arranged along the cutter 502; the moving block 802 and the fixed strip 801 are connected through an extension piece 803; the moving block 802 is thrown out along the cutter 502 due to the rotating centrifugal force, and the extension piece 803 adjusts the length accordingly; the side end of the moving block 802 in the throwing-out direction is provided with a ball cavity B8021; as the moving block 802 is thrown out, the ball cavity B8021 first forms a semi-spherical cavity with the ball cavity A5022; the moving block 802 continues to throw out to push the cut-off melt line particles along the arc-shaped cavity 5023; and the melt line particles rolling along the arc-shaped cavity 5023 are rolled into spherical shape and then thrown out to contact the water film.

[0075] In the embodiment, the extension piece 803 adopts an extension tube, and the extension tube is fixedly connected with the moving block 802 and the fixed strip 801 at both ends.

[0076] In the embodiment, the inner wall of the communication part between the ball cavity A5022 and the arc-shaped cavity 5023 is continuous; the melt line particles pushed by the ball cavity B8021 are not hindered to enter the arc-shaped cavity 5023 from the ball cavity A5022.

[0077] During the movement of the ball cavity B8021 along the arc-shaped cavity 5023, the melt line particles rolling in the arc-shaped cavity 5023 are pushed and extruded by the spherical surface of the ball cavity B8021 to be shaped. The melt line particles entering the ball cavity A5022 are pushed by the moving ball cavity B8021 to enter the arc-shaped cavity 5023, the melt line particles roll along the arc-shaped cavity 5023, and the spherical surface of the ball cavity B8021 cooperates with the arc-shaped cavity 5023 to shape the melt line particles into spherical shape.

[0078] The guide unit 600 comprises a connecting ring 601 and a guide ring 602; the connecting ring 601 is fixed on the extrusion side of the die head 900 through a connecting block 603, and the guide ring 602 is fixed on the inner periphery of the connecting ring 601; the side end of the moving block 802 in the throwing-out direction is fixed with a guide rod 804, and the guide rod 804 is in contact with the wavy inner periphery of the guide ring 602 and performs reciprocating motion. During the rotation of the guide rod 804, the guide rod 804 rises and falls along the wavy inner periphery of the guide ring 602, so as to perform reciprocating motion, and the moving block 802 moves along the cutter 502 reciprocatingly.

[0079] The moving block 802 performs the rolling process when passing through the recessed part of the guide ring 602, and retreats when passing through the protruding guide part of the guide ring 602 to wait for performing the next rolling process on the melt line particles.

[0080] In the embodiment, please refer to Figures 4 to 7 The contact end of the guide rod 804 is provided with a spherical surface, and the guide rod 804 has small resistance when guiding the guide ring 602. The contact end of the guide rod 804 can also be provided with a ball.

[0081] In this embodiment, the inner periphery of the guide ring 602 can also be provided with a corresponding groove, and the contact end of the guide rod 804 slides along the groove.

[0082] Please refer to Figures 4 to 7 , the cutter 502 on the cutting side along the rotation direction of the cutter group 500 is provided with an inclined surface A5021, and the spherical cavity A5022 and the arc-shaped cavity 5023 are located at the inclined surface A5021. The inclined surface B8022 is provided at the displacement block 802 corresponding to the spherical cavity B8021, and the inclined surface B8022 is in contact with the inclined surface A5021. The melt line particles are cut off and enter the spherical cavity A5022, and the melt line particles are embedded in the spherical cavity A5022 with interference. After the spherical cavity B8021 and the arc-shaped cavity 5023 form a hemispherical cavity, the spherical cavity B8021 continues to move, and the excess part of the melt line particles is cut off. The cut-off part is pushed by the side surface at the inclined surface B8022 and moves along the inclined surface A5021. The cut-off part is expanded in the range of throwing out along the rotation of the inclined surface A5021.

[0083] Working principle: the molten material after melting by the granulation equipment is extruded by the die head 900, and the cutter 502 driven by the motor 300 rotates at high speed along the surface of the die head 900. The extruded melt line particles are cut off and pushed into the spherical cavity A5022 along with the rotation of the cutter 502. At this time, the guide rod 804 on the displacement block 802 will enter the recess of the guide ring 602. After the melt line particles enter the spherical cavity A5022, the guide rod 804 is located in the recess of the guide ring 602 due to the centrifugal force of the high-speed rotation of the cutter 502. In this process, the spherical cavity B8021 on the displacement block 802 first forms a hemispherical cavity with the spherical cavity A5022. With the continuous throwing out of the spherical cavity B8021, the spherical cavity B8021 cuts off the excess part of the melt line particles at the edge. The spherical cavity B8021 continues to throw out and push the cut-off melt line particles along the arc-shaped cavity 5023 connected with the spherical cavity A5022. The melt line particles rolling along the arc-shaped cavity 5023 are rubbed into spherical shape and then thrown out. The melt line particles after throwing out contact the water film for cooling.

[0084] In this process, the cut-off part of the melt line particles is pushed by the side surface at the inclined surface B8022 and moves along the inclined surface A5021. The cut-off part is expanded in the range of throwing out along the rotation of the inclined surface A5021.

[0085] With the rotation continuing, until the guide rod 804 contacts the next protrusion of the guide ring 602, the guide rod 804 contacts the end from the corresponding guide ring 602 protrusion into the side, the guide rod 804 is pushed back, the displacement block 802 is pushed back along the cutter 502, the displacement block 802 is pushed back to expose the ball cavity A 5022, at this time the cutter 502 rotates to the next discharge port 901 of the die head 900, the cutter 502 continues to cut off the extruded melt line particles into the ball cavity A 5022, the guide rod 804 enters the next guide ring 602 recess again to repeat the above process.

[0086] The cut melt line particles maintain a high proportion of spherical shape and the mixed water is discharged from the bottom outlet of the cutting chamber 400.

[0087] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No feature of the application is to be construed as limiting the scope of the claims to their precise configuration set forth herein.

Claims

1. A plastic pelletizing device comprising a die (900) having a circular array of discharge ports (901) formed therein, characterized in that: Also include the knife group (500) and shift block (802) with rotation function; The knife group (500) is provided with a plurality of cutters (502), each cutter (502) is provided with a receiving cavity capable of being in contact with the cutting surface of the discharge port (901), a shift block (802) with reciprocating motion is arranged above the receiving cavity, a rolling cavity is arranged on the shift block (802), and a channel capable of passing through the ball is formed between the rolling cavity and the receiving cavity during the reciprocating motion of the shift block (802), the cross section of the channel is not greater than that of the discharge port (901), and the rolling unit (800) is further included; the rolling unit (800) includes a fixed strip (801) and a shift block (802); the fixed strip (801) is fixed on the cutter (502), the shift block (802) is movably arranged along the cutter (502), and the shift block (802) and the fixed strip (801) are connected through the telescopic piece (803); a ball cavity B (8021) is arranged at the side end of the shift block (802) in the throwing direction, and the ball cavity B (8021) serves as the rolling cavity; The guiding unit (600) is further included, and the guiding unit (600) includes a connecting ring (601) and a guiding ring (602); The connecting ring (601) is fixed on the extrusion side of the die head (900) through the connecting block (603), and the guiding ring (602) is fixed on the inner periphery of the connecting ring (601); The shift block (802) is fixed with a guiding rod (804) at the side end in the throwing direction, the guiding rod (804) is in contact with the wavy inner periphery of the guiding ring (602) and reciprocates.

2. The plastic pelletizing apparatus of claim 1, wherein: A plurality of knife handles (501) are arranged in an annular array on the knife group (500), the cutter (502) is connected to the knife handle (501) through a bolt, and the cutter (502) cutting side rotates at high speed on the surface of the die head (900).

3. A plastic pelletizing apparatus according to claim 2, wherein: The cutter (502) cutting side along the rotation direction of the knife group (500) is provided with a bevel A (5021), the cutter (502) cutting side at the bevel A (5021) is sequentially provided with a ball cavity A (5022) and an arc cavity (5023), the ball cavity A (5022) serves as the receiving cavity, and the arc cavity (5023) serves as the channel through which the ball passes.

4. The plastic pelletizing apparatus of claim 1, wherein: During the movement of the ball cavity B (8021) along the arc cavity (5023), the molten particles rolling in the arc cavity (5023) are pushed and extruded by the spherical surface of the ball cavity B (8021) to be shaped.

5. The plastic pelletizing apparatus of claim 1, wherein: The shift block (802) corresponding to the ball cavity B is provided with a bevel B (8022), and the bevel B (8022) is in contact with the bevel A (5021).

6. The plastic pelletizing apparatus of claim 1, wherein: The contact end of the guiding rod (804) and the guiding ring (602) is provided with a spherical surface.

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