Granulator for thermoplastic polyurethane production and granulation method thereof

Abstract

The invention discloses a granulator for thermoplastic polyurethane production and a granulation method thereof, relates to the field of thermoplastic polyurethane production, and aims to solve the problem that an existing granulator in the prior art is composed of an extrusion device, a cooling water tank and a granulation device. After being extruded by the extrusion device, thermoplastic polyurethane needs to fall into the cooling water tank to be cooled and then is manually pulled into the pelletizing device. However, in the process, the polyurethane strip is easy to bend and deform when falling into the water tank, and manual traction operation is tedious. A rectangular extrusion part is fixedly arranged in the middle of the end face of one side of the extrusion device, a plurality of heat insulation pipes are connected to one side of the rectangular extrusion part, a first connecting plate is fixedly connected to the other sides of the heat insulation pipes, a cooling box is connected to one side of the first connecting plate, and a plurality of heat exchange pipes are fixedly arranged in the middle of the interior of the cooling box. One ends of the multiple heat exchange pipes extend out of the end face of one side of the cooling box and are jointly and fixedly connected with a second connecting plate, and the end face of the other side of the cooling box is fixedly connected with a pelletizing device.

Description

Technical Field

[0001] The invention relates to the field of thermoplastic polyurethane production, in particular to a granulator for thermoplastic polyurethane production and a granulation method thereof. Background Art

[0002] Thermoplastic polyurethane (TPU) is a thermoplastic elastomer made by mixing specific chemical substances (such as MDI containing NCO functional groups and POLYOL containing OH functional groups, etc.). It has the characteristics of both plastics and rubbers, and has the advantages of high elasticity, low temperature resistance, wear resistance, oil resistance, water resistance, weather resistance, and environmental protection and non-toxicity. These characteristics make TPU widely used in many fields such as the automotive industry, electronics, health care, sports and leisure. It is an important plastic material that can meet a variety of stringent application requirements. Thermoplastic polyurethane particles need to be produced using a granulator.

[0003] The existing granulator includes an extruder and a pelletizer, between which a cooling water tank is arranged. After the thermoplastic polyurethane is extruded by the extruder, it needs to fall into the cooling water tank for cooling and then be manually pulled into the pelletizer one by one for pelletizing. The extruded thermoplastic polyurethane strips bend and are easy to deform when falling into the cooling water tank, and the manual pulling method is relatively troublesome. Therefore, the market urgently needs to develop a granulator for thermoplastic polyurethane production to help people solve the existing problems. Summary of the invention

[0004] The object of the present invention is to provide a granulator for thermoplastic polyurethane production, so as to solve the problem that the existing granulator proposed in the above background technology includes an extruder and a pelletizer, a cooling water tank is arranged between the extruder and the pelletizer, and after the thermoplastic polyurethane is extruded by the extruder, it needs to fall into the cooling water tank for cooling and then be manually pulled into the pelletizer one by one for pelletizing, the extruded thermoplastic polyurethane strips are bent and easily deformed when falling into the cooling water tank, and the manual pulling method is relatively troublesome.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a granulator for producing thermoplastic polyurethane, comprising an extrusion device, a rectangular extrusion part is fixedly arranged in the middle of one end face of the extrusion device, a plurality of insulation tubes are connected to one side of the rectangular extrusion part, an extrusion plate is fixedly connected to one side of the plurality of insulation tubes, a plurality of extrusion holes are arranged in the middle of the extrusion plate, a first connecting plate is fixedly connected to the other side of the plurality of insulation tubes, a cooling box is connected to one side of the first connecting plate, a plurality of heat exchange tubes are fixedly arranged in the middle of the cooling box, one end of the plurality of heat exchange tubes extends out of the end face of one side of the cooling box and is fixedly connected to a second connecting plate, and a pelletizing device is fixedly connected to the other end face of the cooling box.

[0006] Preferably, a feed hopper is fixedly provided on one side of the upper end face of the extrusion device, a conveying cylinder is fixedly connected to the middle part of the interior of the extrusion device, the lower end of the feed hopper extends into the interior of the extrusion device and is communicated with the interior of the conveying cylinder, a plurality of heating plates are fixedly provided on the outer end face of the conveying cylinder, one side of the conveying cylinder is fixedly connected to one end face of the interior of the extrusion device, a convergence portion is provided on the other side of the conveying cylinder, one side of the convergence portion is fixedly connected to the other end face of the interior of the extrusion device, and the interior of the convergence portion is communicated with the interior of the rectangular extrusion portion.

[0007] Preferably, a first rotating shaft is rotatably connected to the middle part of the conveying cylinder, a spiral conveying blade is fixedly provided on the first rotating shaft, a first driving device is fixedly provided on one end face of the extrusion device, a first motor is fixedly provided inside the first driving device, and one end of the first rotating shaft extends into the first driving device and is fixedly connected to the output shaft of the first motor.

[0008] Preferably, the upper and lower end surfaces of the rectangular extrusion portion are fixedly connected to connecting wing plates on one side, the upper and lower ends of the extrusion plate are respectively fixedly connected to the two connecting wing plates by a plurality of first bolts, and the plurality of extrusion holes are respectively aligned with a plurality of insulation tubes.

[0009] Preferably, the upper and lower ends of the first connecting plate and the second connecting plate are fixedly connected by a plurality of second bolts, a connection port is provided on one side of each of the plurality of insulation tubes, the connection ports on the plurality of insulation tubes are respectively aligned with the inside of a plurality of heat exchange tubes, and a smooth coating is provided on the inner walls of the insulation tubes and the heat exchange tubes.

[0010] Preferably, the other ends of the plurality of heat exchange tubes pass through an end surface of one side of the cooling box and are flush with an outer end surface of the cooling box, and the plurality of heat exchange tubes are provided with discharge ports on an end surface of one side of the cooling box.

[0011] Preferably, a second rotating shaft is rotatably connected to the middle part of the pelletizing device, a rotating roller is fixedly provided on the second rotating shaft, a plurality of pelletizing knives are fixedly connected to the rotating roller, and a drop port is provided at the lower end of the pelletizing device.

[0012] Preferably, a second driving device is fixedly connected to the front end of the pelletizing device, and a second motor is fixedly arranged inside the second driving device.

[0013] Preferably, the front end of the second rotating shaft extends into the interior of the second driving device and is fixedly connected to the output shaft of the second motor.

[0014] A hot pressing method comprises the following steps: Step 1: Feed the thermoplastic polyurethane material into the conveying cylinder through the feed hopper, and drive the first rotating shaft to rotate through the first motor, so that the first rotating shaft drives the spiral conveying blade to rotate, and the spiral conveying blade pushes the thermoplastic polyurethane material to move toward the convergence part when rotating. When the thermoplastic polyurethane material moves, it is heated and melted by multiple heating plates on the conveying cylinder, and the melted thermoplastic polyurethane material enters the rectangular extrusion part after being pressurized by the convergence part; Step 2: The melted thermoplastic polyurethane material is extruded into the interior of the plurality of heat-insulating tubes through the plurality of extrusion holes on the extrusion plate under pressure in the rectangular extrusion part, and the extrusion thrust pushes the thermoplastic polyurethane strip to move inside the heat-insulating tube and enter the heat exchange tube through the connecting port, and the extrusion thrust continues to push the thermoplastic polyurethane strip to move inside the heat exchange tube and enter the cooling box; Step 3: inject a large amount of cooling water into the cooling box, cool the heat exchange tube by the cooling water, and then cool and shape the thermoplastic polyurethane strip while moving inside the heat exchange tube. After the thermoplastic polyurethane strip is cooled and shaped, it is discharged from the discharge port into the pelletizing device; Step 4: The second motor inside the second driving device at the front end of the pelletizing device drives the second rotating shaft to rotate. When the second rotating shaft rotates, it synchronously drives the rotating roller. The rotating roller drives multiple pelletizing knives to continuously pelletize the thermoplastic polyurethane strips discharged from the discharge port. After pelletizing, the thermoplastic polyurethane particles fall through the drop port. A collecting box is set at the lower end of the drop port to collect the thermoplastic polyurethane particles.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, by providing an insulating tube, a heat exchange tube and a cooling box, the thermoplastic polyurethane strips are cooled and shaped during transportation, thereby avoiding the problem of bending and deformation of the thermoplastic polyurethane strips when they fall into the cooling water tank in the traditional method, thereby improving the quality and production efficiency of the thermoplastic polyurethane particles.

[0016] (2) In the present invention, spiral conveying blades and heating plates are used to heat and melt the thermoplastic polyurethane material and extrude it evenly. The material is then continuously conveyed and cooled through insulation pipes and heat exchange pipes and then automatically pelletized through a pelletizing device. The entire process does not require manual traction, which greatly improves the degree of production automation and reduces production costs.

[0017] (3) In this invention, the production process of thermoplastic polyurethane particles is simplified by using insulating tubes and heat exchange tubes, reducing the use of cooling water tanks and drying devices in traditional methods, reducing energy consumption and wastewater discharge, complying with the development trend of environmental protection and energy conservation, and having high social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a front view of a granulator for producing thermoplastic polyurethane of the present invention; Figure 2 is a main cross-sectional view of the present invention; Figure 3 is a side sectional view of the extrusion device of the present invention; Figure 4 It is a side sectional view of the pelletizing device of the present invention; Figure 5 It is an enlarged view of detail A of the present invention.

[0019] In the figure: 1. extrusion device; 101. feed hopper; 102. rectangular extrusion part; 103. sealing strip; 104. connecting wing plate; 2. conveying cylinder; 201. first rotating shaft; 202. spiral conveying blade; 203. converging part; 204. heating plate; 3. first driving device; 301. first motor; 4. insulation tube; 401. extrusion plate; 402. extrusion hole; 403. first bolt; 404. first connecting plate; 405. connecting port; 406. second bolt; 5. cooling box; 501. heat exchange tube; 502. second connecting plate; 503. discharge port; 6. pelletizing device; 601. second rotating shaft; 602. rotating roller; 603. pelletizing knife; 604. blanking port; 7. second driving device; 701. second motor. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] See also Figure 1-5An embodiment of the present invention is as follows: a granulator for producing thermoplastic polyurethane, comprising an extruder 1, a feed hopper 101 is fixedly arranged on one side of the upper end face of the extruder 1, a conveying cylinder 2 is fixedly connected to the middle part of the inside of the extruder 1, a first rotating shaft 201 is rotatably connected to the middle part of the inside of the conveying cylinder 2, a spiral conveying blade 202 is fixedly arranged on the first rotating shaft 201, a first driving device 3 is fixedly arranged on one end face of the extruder 1, a first motor 301 is fixedly arranged inside the first driving device 3, one end of the first rotating shaft 201 extends into the inside of the first driving device 3 and is fixedly connected to the output shaft of the first motor 301, a lower end of the feed hopper 101 extends into the inside of the extruder 1 and is connected to the inside of the conveying cylinder 2, a plurality of heating plates 204 are fixedly arranged on the outer end face of the conveying cylinder 2, one side of the conveying cylinder 2 is connected to the inside of the extruder 1 The end face of one side of the conveying cylinder 2 is fixedly connected, and the other side of the conveying cylinder 2 is provided with a convergence portion 203. One side of the convergence portion 203 is fixedly connected to the end face of the other side inside the extrusion device 1. A rectangular extrusion portion 102 is fixedly provided in the middle of the end face of one side of the extrusion device 1. The interior of the convergence portion 203 is communicated with the interior of the rectangular extrusion portion 102. The thermoplastic polyurethane material is fed into the conveying cylinder 2 through the feed hopper 101, and the first rotating shaft 201 is driven to rotate by the first motor 301, so that the first rotating shaft 201 drives the spiral conveying blade 202 to rotate. When the spiral conveying blade 202 rotates, it pushes the thermoplastic polyurethane material to move toward the convergence portion 203. When the thermoplastic polyurethane material moves, it is heated and melted by multiple heating plates 204 on the conveying cylinder 2. The melted thermoplastic polyurethane material enters the interior of the rectangular extrusion portion 102 after being pressurized by the convergence portion 203.

[0022] See also Figure 2 , Figure 3 and Figure 5 A plurality of heat-insulating tubes 4 are connected to one side of the rectangular extrusion portion 102, an extrusion plate 401 is fixedly connected to one side of the plurality of heat-insulating tubes 4, a plurality of extrusion holes 402 are arranged in the middle of the extrusion plate 401, a first connecting plate 404 is fixedly connected to the other side of the plurality of heat-insulating tubes 4, a connecting wing plate 104 is fixedly connected to one side of the upper and lower end surfaces of the rectangular extrusion portion 102, the upper and lower ends of the extrusion plate 401 are respectively fixedly connected to the two connecting wing plates 104 through a plurality of first bolts 403, the plurality of extrusion holes 402 are respectively aligned with the plurality of heat-insulating tubes 4, and the melted thermoplastic polyurethane material is extruded into the plurality of heat-insulating tubes 4 through the plurality of extrusion holes 402 on the extrusion plate 401 under pressure inside the rectangular extrusion portion 102.

[0023] See also Figure 2 , Figure 3 and Figure 5A cooling box 5 is connected to one side of the first connecting plate 404, and a plurality of heat exchange tubes 501 are fixedly arranged in the middle of the cooling box 5. One end of the plurality of heat exchange tubes 501 extends out of the end surface of one side of the cooling box 5 and is fixedly connected to the second connecting plate 502. The upper and lower ends of the first connecting plate 404 and the second connecting plate 502 are fixedly connected by a plurality of second bolts 406. A connecting port 405 is arranged on one side of the plurality of heat insulation tubes 4. The connecting ports 405 on the plurality of heat insulation tubes 4 are respectively aligned with the inside of the plurality of heat exchange tubes 501. A smooth coating is arranged on the inner walls of the heat insulation tubes 4 and the heat exchange tubes 501. The thermoplastic polyurethane strip is pushed to move inside the heat insulation tube 4 through the thrust of the extrusion and enters the heat exchange tube 501 through the connecting port 405. The thrust of the subsequent extrusion pushes the thermoplastic polyurethane strip to move inside the heat exchange tube 501 and into the cooling box 5. The thermoplastic polyurethane strip is transported to the inside of the heat exchange tube 501 through the insulation tube 4 and is cooled in the cooling box 5 through the heat exchange tube 501. The thermoplastic polyurethane strip will not bend when moving through the insulation tube 4 and the inside of the heat exchange tube 501, thereby preventing the thermoplastic polyurethane strip from bending and deforming. At the same time, the thermoplastic polyurethane strip is cooled by moving inside the heat exchange tube 501 and through the cooling box 5, thereby improving the cooling efficiency. There is no need to use the traditional method of using the thermoplastic polyurethane strip to enter the cooling water tank for cooling, so that cooling water will not adhere to the surface of the thermoplastic polyurethane strip, so that the subsequent thermoplastic polyurethane particles do not need to be dried by a drying device and can be directly bagged, thereby improving production efficiency.

[0024] See also Figure 2 and Figure 4 A pelletizing device 6 is fixedly connected to the end surface of the other side of the cooling box 5, and a second rotating shaft 601 is rotatably connected to the middle part of the pelletizing device 6. A rotating roller 602 is fixedly arranged on the second rotating shaft 601, and a plurality of pelletizing knives 603 are fixedly connected to the rotating roller 602. A drop opening 604 is arranged at the lower end of the pelletizing device 6, and a second driving device 7 is fixedly connected to the front end of the pelletizing device 6. A second motor 701 is fixedly arranged inside the second driving device 7. The front end of the second rotating shaft 601 extends to the inside of the second driving device 7 and is fixedly connected to the output shaft of the second motor 701. The second motor 701 drives the second rotating shaft 601 to rotate, and the second rotating shaft 601 drives the rotating roller 602 synchronously when rotating. The rotating roller 602 rotates to drive multiple pelletizing knives 603 to continuously pelletize the thermoplastic polyurethane strips discharged from the discharge port 503. After pelletizing, the thermoplastic polyurethane particles fall through the drop port 604. A collecting box is provided at the lower end of the drop port 604 to collect the thermoplastic polyurethane particles. The thermoplastic polyurethane strips at the discharge port 503 are directly pelletized by the pelletizing knife 603, and there is no need to manually pull the thermoplastic polyurethane strips, thereby improving the degree of automation of the thermoplastic polyurethane particles.

[0025] A hot pressing method comprises the following steps: Step 1: Feed the thermoplastic polyurethane material into the conveying cylinder 2 through the feed hopper 101, and drive the first rotating shaft 201 to rotate through the first motor 301, so that the first rotating shaft 201 drives the spiral conveying blade 202 to rotate, and the spiral conveying blade 202 pushes the thermoplastic polyurethane material to move toward the convergence part 203 when rotating. When the thermoplastic polyurethane material moves, it is heated and melted by the multiple heating plates 204 on the conveying cylinder 2, and the melted thermoplastic polyurethane material enters the rectangular extrusion part 102 after being pressurized by the convergence part 203; Step 2: The melted thermoplastic polyurethane material is extruded into the plurality of heat-insulating tubes 4 through the plurality of extrusion holes 402 on the extrusion plate 401 under pressure in the rectangular extrusion portion 102, and the extrusion thrust pushes the thermoplastic polyurethane strip to move in the heat-insulating tube 4 and enter the heat exchange tube 501 through the connection port 405, and the extrusion thrust continues to push the thermoplastic polyurethane strip to move in the heat exchange tube 501 and enter the cooling box 5; Step 3: a large amount of cooling water is injected into the cooling box 5, and the heat exchange tube 501 is cooled by the cooling water, so that the thermoplastic polyurethane strip is cooled and shaped while moving inside the heat exchange tube 501. After the thermoplastic polyurethane strip is cooled and shaped, it is discharged from the discharge port 503 and enters the pelletizing device 6; Step 4: The second motor 701 inside the second driving device 7 at the front end of the pelletizing device 6 drives the second rotating shaft 601 to rotate. When the second rotating shaft 601 rotates, it synchronously drives the rotating roller 602. The rotating roller 602 rotates to drive multiple pelletizing knives 603 to continuously pelletize the thermoplastic polyurethane strips discharged from the discharge port 503. After pelletizing, the thermoplastic polyurethane particles fall through the drop port 604. A collecting box is set at the lower end of the drop port 604 to collect the thermoplastic polyurethane particles.

[0026] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A granulator for producing thermoplastic polyurethane, comprising an extruder (1), characterized in that: A rectangular extrusion portion (102) is fixedly arranged in the middle of one end face of the extrusion device (1), one side of the rectangular extrusion portion (102) is connected to a plurality of heat-insulating tubes (4), one side of the plurality of heat-insulating tubes (4) is fixedly connected to an extrusion plate (401), the middle of the extrusion plate (401) is provided with a plurality of extrusion holes (402), the other side of the plurality of heat-insulating tubes (4) is fixedly connected to a first connecting plate (404), one side of the first connecting plate (404) is connected to a cooling box (5), a plurality of heat exchange tubes (501) are fixedly arranged in the middle of the cooling box (5), one end of the plurality of heat exchange tubes (501) extends out of one end face of the cooling box (5) and is fixedly connected to a second connecting plate (502), and a pelletizing device (6) is fixedly connected to the other end face of the cooling box (5).

2. The granulator for producing thermoplastic polyurethane according to claim 1, characterized in that: A feed hopper (101) is fixedly arranged on one side of the upper end face of the extrusion device (1), a conveying cylinder (2) is fixedly connected to the middle part of the interior of the extrusion device (1), the lower end of the feed hopper (101) extends into the interior of the extrusion device (1) and is in communication with the interior of the conveying cylinder (2), a plurality of heating plates (204) are fixedly arranged on the outer end face of the conveying cylinder (2), one side of the conveying cylinder (2) is fixedly connected to the end face of one side of the interior of the extrusion device (1), a converging portion (203) is arranged on the other side of the conveying cylinder (2), one side of the converging portion (203) is fixedly connected to the end face of the other side of the interior of the extrusion device (1), and the interior of the converging portion (203) is in communication with the interior of the rectangular extrusion portion (102).

3. The granulator for producing thermoplastic polyurethane according to claim 2, characterized in that: A first rotating shaft (201) is rotatably connected to the middle of the conveying cylinder (2), a spiral conveying blade (202) is fixedly arranged on the first rotating shaft (201), a first driving device (3) is fixedly arranged on one end surface of the extrusion device (1), a first motor (301) is fixedly arranged inside the first driving device (3), and one end of the first rotating shaft (201) extends into the first driving device (3) and is fixedly connected to the output shaft of the first motor (301).

4. The granulator for producing thermoplastic polyurethane according to claim 1, characterized in that: The upper and lower end surfaces of the rectangular extrusion portion (102) are both fixedly connected to connecting wing plates (104), the upper and lower ends of the extrusion plate (401) are respectively fixedly connected to the two connecting wing plates (104) via a plurality of first bolts (403), and the plurality of extrusion holes (402) are respectively aligned with a plurality of thermal insulation tubes (4).

5. The granulator for producing thermoplastic polyurethane according to claim 1, characterized in that: The upper and lower ends of the first connecting plate (404) and the second connecting plate (502) are fixedly connected by a plurality of second bolts (406); a connection port (405) is provided on one side of the plurality of insulation tubes (4); the connection ports (405) on the plurality of insulation tubes (4) are respectively aligned with the inside of the plurality of heat exchange tubes (501); and a smooth coating is provided on the inner walls of the insulation tubes (4) and the heat exchange tubes (501).

6. The granulator for producing thermoplastic polyurethane according to claim 1, characterized in that: The other ends of the plurality of heat exchange tubes (501) pass through an end surface of one side of the cooling box (5) and are flush with an outer end surface of the cooling box (5); and the plurality of heat exchange tubes (501) are provided with a discharge port (503) on an end surface of one side of the cooling box (5).

7. The granulator for producing thermoplastic polyurethane according to claim 1, characterized in that: A second rotating shaft (601) is rotatably connected to the middle part of the pelletizing device (6), a rotating roller (602) is fixedly arranged on the second rotating shaft (601), a plurality of pelletizing knives (603) are fixedly connected to the rotating roller (602), and a material drop opening (604) is arranged at the lower end of the pelletizing device (6).

8. The granulator for producing thermoplastic polyurethane according to claim 7, characterized in that: The front end of the pelletizing device (6) is fixedly connected to a second driving device (7), and a second motor (701) is fixedly arranged inside the second driving device (7).

9. The granulator for producing thermoplastic polyurethane according to claim 8, characterized in that: The front end of the second rotating shaft (601) extends into the interior of the second driving device (7) and is fixedly connected to the output shaft of the second motor (701).

10. A hot pressing method, implemented based on a hot pressing device for processing raw bamboo fiber side panel according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: feeding a thermoplastic polyurethane material into the interior of a conveying cylinder (2) through a feed hopper (101), driving a first rotating shaft (201) to rotate through a first motor (301), causing the first rotating shaft (201) to drive a spiral conveying blade (202) to rotate, and pushing the thermoplastic polyurethane material toward a convergence portion (203) when the spiral conveying blade (202) rotates, and the thermoplastic polyurethane material is heated and melted by a plurality of heating plates (204) on the conveying cylinder (2) when the thermoplastic polyurethane material moves, and the melted thermoplastic polyurethane material is pressurized by the convergence portion (203) and enters the interior of a rectangular extrusion portion (102); Step 2: The melted thermoplastic polyurethane material is extruded into the plurality of heat-insulating tubes (4) through the plurality of extrusion holes (402) on the extrusion plate (401) under pressure inside the rectangular extrusion portion (102); the extrusion thrust forces the thermoplastic polyurethane strip to move inside the heat-insulating tube (4) and enter the heat exchange tube (501) through the connection port (405); the extrusion thrust forces continue to push the thermoplastic polyurethane strip to move inside the heat exchange tube (501) and enter the cooling box (5); Step 3: injecting a large amount of cooling water into the cooling box (5), cooling the heat exchange tube (501) with the cooling water, thereby cooling and shaping the thermoplastic polyurethane strip while moving inside the heat exchange tube (501); after the thermoplastic polyurethane strip is cooled and shaped, it is discharged from the discharge port (503) into the pelletizing device (6); Step 4: The second motor (701) inside the second driving device (7) at the front end of the pelletizing device (6) drives the second rotating shaft (601) to rotate. When the second rotating shaft (601) rotates, it simultaneously drives the rotating roller (602). The rotating roller (602) drives the plurality of pelletizing knives (603) to continuously pelletize the thermoplastic polyurethane strips discharged from the discharge port (503). After pelletizing, the thermoplastic polyurethane particles fall through the drop port (604). A collection box is provided at the lower end of the drop port (604) to collect the thermoplastic polyurethane particles.

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