A twin-screw extruder for melting bottle chips

Abstract

The application discloses a double-screw extruder for melting bottle pieces, and relates to the technical field of plastic production and processing.The double-screw extruder comprises a feeding bin, a machine box one, a cutting unit, a crushing unit, a cleaning unit, a conveying unit, a power unit and a melting cylinder.The feeding bin is installed on the upper end face of the machine box one.The machine box one is connected with a machine box two.The cutting unit, the crushing unit and the cleaning unit are installed in the machine box one.The conveying unit is installed in the connecting part between the machine box one and the machine box two.The power unit is installed on the left end face of the machine box two.The melting cylinder is installed in the machine box two.The power unit is connected with the melting cylinder.The bottle cap and the bottle bottom are removed through a physical treatment method, and then the bottle body label is removed.The double-screw extruder is provided with a melting backflow system, so that the quality and color of the PET bottle formed through melting are improved.

Description

Technical Field

[0001] This invention relates to the field of plastic production and processing technology, specifically a twin-screw extruder for melting bottle flakes. Background Technology

[0002] The physical recycling of PET plastic bottles is relatively simple, mainly involving drying and granulating the cleaned PET waste. This physical recycling method is closely linked to the sorting process. There are two main types of physical recycling methods: one is to shred the waste PET plastic bottles into flakes, separating HDPE, aluminum, paper, and adhesives from the PET. The PET fragments are then washed, dried, and granulated. The other method involves mechanically separating non-PET impurities such as bottle caps, bases, and labels from the waste PET plastic bottles, followed by washing, crushing, and granulation. Recycled PET must not contain PVC impurities, otherwise it will affect the color of the PET.

[0003] The prior art CN111016132A discloses a twin-screw extruder for preparing temperature-regulating masterbatch. The technical solution discloses that "this invention discloses a twin-screw extruder for preparing temperature-regulating masterbatch, including an extruder body. The extruder body includes a barrel, twin screws, a metering device, and a hopper. Several heaters are installed on the upper and lower parts of the outer side of the barrel. Engaging teeth are also provided inside the L-shaped pipe of the metering device. This invention, by setting a circulating jacket inside the heaters, and the circulating jacket having two circulating heat exchange chambers, can ensure relatively uniform heat distribution around the barrel, preventing localized overheating. Furthermore, when the temperature overheats, a relatively low-temperature heat exchange medium can be introduced into one of the circulating heat exchange chambers to rapidly reduce the temperature to a suitable temperature threshold. By setting a mixing roller with a certain gap inside the hopper, it is convenient to disperse the mixed materials. A feeding screw is set inside the L-shaped pipe, and corresponding engagement teeth and hopper heaters are provided for preliminary extrusion, facilitating mixing."

[0004] Although a twin-screw extruder for preparing temperature-regulating masterbatch has been disclosed in the prior art, there are still some shortcomings. Specifically, during the crushing process, PVC plastic contained in the bottle cap and bottle bottom will be mixed in, resulting in impurities in the extruded PET bottles. During the extrusion melting process, insufficient melting will cause lumps of plastic to be generated in the melting cylinder, which will hinder the efficiency and quality of extrusion molding and is not conducive to normal use. Summary of the Invention

[0005] The purpose of this invention is to provide a twin-screw extruder for melting bottle flakes, in order to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A twin-screw extruder for melting bottle flakes includes a feeding hopper, a first casing, a cutting unit, a crushing unit, a cleaning unit, a conveying unit, a second casing, a power unit, and a melting cylinder. The feeding hopper is installed on the upper surface of the first casing. The cutting unit, crushing unit, and cleaning unit are installed inside the first casing. There is a positional deviation between the cutting unit, crushing unit, and cleaning unit. The first casing and the second casing are connected via a conveying unit. The power unit is installed on the left end face of the second casing. The melting cylinder is installed inside the second casing and is connected to the melting cylinder. The cutting unit separates the bottle cap and bottom from the bottle body. The crushing unit crushes the bottle body and its label to remove PVC plastic from the material. The cleaning unit washes away impurities from the material. The material enters the melting cylinder via a conveyor belt, where it is melted and extruded into shape.

[0007] The cutting unit includes a cutting chamber, a hydraulic pump 1, a piston rod 1, a blade 1, a support plate, a hydraulic pump 2, a piston rod 2, and a conveying pipe. The cutting chamber is mounted on the support plate, the support plate is connected to the piston rod 2, the piston rod 2 is connected to the hydraulic pump 2, the hydraulic pump 2 is fixed to the surface of the housing 1, the blade 1 is connected to the piston rod 1, the piston rod 1 is connected to the hydraulic pump 1, the hydraulic pump 1 is fixed to the surface of the housing 1, and the conveying pipe is installed below the support plate.

[0008] The crushing unit includes a crushing chamber and a fixing plate. The fixing plate is installed on the inner wall of the housing and connected to the crushing chamber. A crossbeam is installed above the crushing chamber, and a motor is installed above the crossbeam. A stirring shaft on the main shaft of the motor is equipped with blades. A valve plate is installed at the bottom of the crushing chamber, and a blower is installed below the crushing chamber. The two blades installed on the stirring shaft are used to crush materials. The valve plate at the bottom of the crushing chamber is used to control the discharge of materials, and the blower is used to blow out the crushed labels.

[0009] The cleaning unit includes a second motor, a cleaning chamber, a second fixing plate, and a water pump. The second fixing plate is installed on the inner wall of a first casing and is connected to the cleaning chamber. A second crossbeam is installed above the cleaning chamber, and the second motor is installed above the crossbeam. Agitator blades are mounted on the stirring shaft of the motor's main shaft. A drain pipe is installed on the side wall of the cleaning chamber. One side of the cleaning chamber is connected to the water pump via a pipeline. A second valve plate is installed at the bottom of the cleaning chamber. The second fixing plate ensures the stability and reliability of the entire cleaning unit. The second motor is the power source of the cleaning unit; its main shaft has a stirring shaft with fixed stirring blades, which efficiently stirs the liquid in the cleaning chamber, ensuring a uniform and thorough cleaning effect.

[0010] The drainage pipes can promptly remove wastewater generated during the cleaning process.

[0011] The conveying unit includes a stainless steel mesh conveyor belt, a third electric motor, and a first heating block. The stainless steel mesh conveyor belt is installed at the connection between chassis one and chassis two. A roller is installed inside the stainless steel mesh conveyor belt. The main shaft of the third electric motor is connected to the roller. The heating block is installed inside the stainless steel mesh conveyor belt. The power unit includes a power chamber, a fourth electric motor, a drive gear, and driven gears. The power chamber is installed on the side wall of chassis two. The fourth electric motor is installed inside the power chamber. The main shaft of the fourth electric motor is connected to the drive gear. The drive gear is connected to the two driven gears through gear meshing. The roller supports the conveyor belt and reduces friction, ensuring smooth operation of the conveyor belt. The third electric motor drives the roller to rotate, thereby driving the movement of the stainless steel mesh conveyor belt. The heating block can evenly heat the material on the conveyor belt, drying the material.

[0012] The power unit includes a power compartment, an electric motor, a drive gear, and driven gears. The power compartment is installed on the side wall of the chassis, which is beneficial for the heat dissipation of the power unit. The drive gear is connected to the two driven gears through precise gear meshing, which ensures the even distribution and transmission of power, thereby making the operation of the entire system more stable and efficient.

[0013] A reflux chamber is installed at the right end of the cylinder. A valve plate (3) is installed at the bottom of the reflux chamber. A baffle (2) is installed inside the reflux chamber. A piston rod (4) is installed on the baffle (2) and connected to a hydraulic pump (4). A heating block (2) is installed on the side wall of the reflux chamber, and a heating wire is installed inside the heating block (2). A perforated plate is installed at the right end of the baffle, and a discharge port is installed at the right end of the perforated plate. Four support columns (1) are installed at the four corners below the chassis (1). Two support columns (2) are installed below the power unit. Six support columns (3) are installed below the chassis (2).

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. This twin-screw extruder for melting bottle flakes is optimized in design. Before the material enters the crushing chamber, the cap and bottom of the waste bottle are removed by the cutting unit, and the label after the bottle body is crushed is removed by the blower. The PVC material in the cap, bottom and label is removed, which improves the quality of the final melted bottle flakes.

[0016] 2. During the melt extrusion process, there may be insufficient melting, which can block the discharge port and reduce the discharge efficiency. A reflux chamber is installed at the right end of the melting cylinder. The unmelted bottle flakes will enter the reflux chamber. The reflux chamber is equipped with heating pipes to reheat and melt the unmelted bottle flakes before they flow back into the melting cylinder, thus improving the discharge efficiency of the entire system. Attached Figure Description

[0017] Figure 1 This is a perspective view of the present invention;

[0018] Figure 2 This is a rear view of the present invention;

[0019] Figure 3 This is a cross-sectional view of the present invention;

[0020] Figure 4 This is a perspective view of the internal structure of the present invention;

[0021] Figure 5 This is a perspective view of the internal structure of the melting cylinder of the present invention;

[0022] Figure 6 This is a perspective view of the cutting unit of the present invention;

[0023] Figure 7 This is a perspective view of the crushing unit and the cleaning unit of the present invention;

[0024] Figure 8 For the present invention Figure 3 A magnified view of a portion of region A in the middle.

[0025] In the diagram: 1. Feed hopper; 2. Chassis 1; 3. Chassis 2; 4. Cutting unit; 41. Cutting chamber; 42. Fixed plate 1; 43. Hydraulic pump 1; 44. Piston rod 1; 45. Blade 1; 46. Hydraulic pump 2; 47. Piston rod 2; 48. Support plate; 49. Conveying pipe; 5. Crushing unit; 51. Motor 1; 52. Crossbeam 1; 53. Crushing chamber; 54. Blade 2; 55. Valve plate 1; 56. Fixed plate 2; 6. Blower; 7. Cleaning unit; 71. Motor 2; 72. Crossbeam 2; 73. Cleaning chamber; 74. Water pump; 75. Water tank; 76. Drainage pipe; 77. Valve 1; 78. Valve 2; 79. Valve plate 2; 710. Fixed plate 3; 711. Mixing blades; 8. Conveying unit; 81. 82. Electric motor 3; 83. Drum; 84. Stainless steel mesh conveyor belt; 9. Heating block 1; 10. Storage bin; 11. Power unit; 101. Power chamber; 102. Electric motor 4; 103. Drive gear; 104. Driven gear; 11. Melting cylinder; 111. Cylinder body; 112. Screw; 113. Fixing plate 4; 114. Heating wire; 115. Return chamber; 116. Heating block 2; 117. Hydraulic pump 3; 118. Piston rod 3; 119. Baffle 1; 1110. Valve plate 3; 1111. Perforated plate; 1112. Discharge port; 1113. Pressure sensor; 1114. Baffle 2; 1115. Piston rod 4; 1116. Hydraulic pump 4; 121. Support column 1; 122. Support column 2; 123. Support column 3. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figures 1-8 This invention provides a technical solution: a twin-screw extruder for melting bottle flakes includes a feed hopper 1, a first casing 2, a cutting unit 4, a crushing unit 5, a cleaning unit 7, a conveying unit 8, a second casing 3, a power unit 10, and a melting cylinder 11. The feed hopper 1 is installed on the upper surface of the first casing 2. The cutting unit 4, crushing unit 5, and cleaning unit 7 are installed inside the first casing 2 from top to bottom, with positional deviations between them. The first casing 2 and the second casing 3 are connected via the conveying unit 8. The power unit 10 is installed on the left end face of the second casing 3. The melting cylinder 11 is installed inside the second casing 3, and the power unit 10 is connected to the melting cylinder 11. The cutting unit 4 separates the bottle cap and bottom from the bottle body. The crushing unit 5 crushes the bottle body and its label to remove PVC plastic from the material. The cleaning unit 7 washes away impurities from the material. The material enters the melting cylinder 11 via the conveying unit 8, where it is melted and extruded into shape.

[0028] The cutting unit 4 includes a cutting chamber 41, a hydraulic pump 43, a piston rod 44, a blade 45, a support plate 48, a hydraulic pump 46, a piston rod 47, and a conveying pipe 49. The fixing plate 42 is installed on the inner wall of the casing 2 and is connected to the cutting chamber 41. The support plate 48 is connected to the piston rod 47, which is connected to the hydraulic pump 46. The hydraulic pump 46 is fixed on the surface of the casing 2. The blade 45 is connected to the piston rod 44, which is connected to the hydraulic pump 43. The hydraulic pump 43 is fixed on the surface of the casing 2. The conveying pipe 49 is installed below the support plate 48. Because there is a positional deviation between the cutting chamber 41 and the crushing chamber 53, the cut bottle body can fall into the crushing chamber 53.

[0029] The crushing unit 5 includes a motor 51, a crossbeam 52, a crushing chamber 53, blades 54, a valve plate 55, and a fixing plate 56. The fixing plate 56 is installed on the inner wall of the casing 2 and is connected to the crushing chamber 53. A crossbeam 52 is installed above the crushing chamber 53, and a motor 51 is installed above the crossbeam 52. Blades 54 are installed on the stirring shaft of the motor 51. A valve plate 55 is installed at the bottom of the crushing chamber 53, and a blower 6 is installed below the crushing chamber 53. The two blades 54 installed on the stirring shaft are used to crush materials. The valve plate 55 at the bottom of the crushing chamber 53 is used to control the discharge of materials. The blower 6 is used to blow out the crushed labels. Because there is a positional deviation between the crushing chamber 53 and the cleaning chamber 73, the crushed bottle flakes can fall into the cleaning chamber 73.

[0030] Cleaning unit 7 includes a second motor 71, a second crossbeam 72, a cleaning chamber 73, a third fixing plate 710, a water pump 74, a drainage pipe 76, a second valve plate 79, and stirring blades 711. The third fixing plate 710 is installed on the inner wall of the casing 2 and is connected to the cleaning chamber 73. The second crossbeam 72 is installed above the cleaning chamber 73, and the second motor 71 is installed above the crossbeam 72. The stirring shaft on the main shaft of the second motor 71 is equipped with stirring blades 711. The drainage pipe 76 is installed on the side wall of the cleaning chamber 73, and one side of the cleaning chamber 73 is connected to the water pump 74 through a pipe. The system is connected by a pipeline. Valve 77 is installed on the pipeline. Water tank 75 is connected to water pump 74 through a pipeline. Valve 78 is installed on the pipeline. Valve plate 79 is installed at the bottom of cleaning chamber 73. Fixing plate 710 is used to ensure the stability and reliability of the entire cleaning unit 7. Motor 71 is the power source of cleaning unit 7. A stirring shaft is installed on its main shaft. Stirring blades 711 are fixed on the stirring shaft. It can efficiently stir the liquid in cleaning chamber 73 to ensure uniform and thorough cleaning. Drainage pipe 76 can discharge wastewater generated during the cleaning process in a timely manner.

[0031] Conveying unit 8 includes a stainless steel mesh conveyor belt 83, a third electric motor 81, and a first heating block 84. The stainless steel mesh conveyor belt 83 is installed at the connection between housing 1 2 and housing 2 3. A roller 82 is installed inside the stainless steel mesh conveyor belt 83. The main shaft of the third electric motor 81 is connected to the roller 82. The first heating block 84 is installed inside the stainless steel mesh conveyor belt 83. Power unit 10 includes a power chamber 101, a fourth electric motor 102, a driving gear 103, and a driven gear 104. The power chamber 101 is installed on the side wall of housing 2 3. The fourth electric motor 102 is installed inside the power chamber 101. The main shaft of the fourth electric motor 102 is connected to the driving gear 103. The driven gear 104 is installed on the side wall of housing 2 3. At one end of the screw 112, the drive gear 103 and two driven gears 104 are connected by gear meshing. The roller 82 supports the conveyor belt and reduces friction, ensuring smooth operation of the conveyor belt. The motor 81 drives the roller 82 to rotate, thereby driving the movement of the stainless steel mesh conveyor belt 83. The heating block 84 can evenly heat the material on the conveyor belt and dry it. The power chamber 101 is installed on the side wall of the casing 3, which is beneficial for the heat dissipation of the power unit 10. The drive gear 103 and two driven gears 104 are connected by precise gear meshing, ensuring the even distribution and transmission of power, thus making the entire system run more smoothly and efficiently.

[0032] Fixed plate 4 113 is installed on the bottom end face of the casing 2 3. Fixed plate 4 113 is connected to cylinder 111. Storage hopper 9 is installed on the left end of cylinder 111 and return chamber 115 is installed on the right end of cylinder 111. Valve plate 3 1110 is set at the bottom of return chamber 115. Baffle 2 1114 is set inside return chamber 115. Piston rod 4 1115 is set on baffle 2 1114. Piston rod 4 1115 is connected to hydraulic pump 4 1116. Heating block 2 116 is set on the side wall of return chamber 115. Heating wire 114 is set inside heating block 2 116.

[0033] A pressure sensor 1113 is installed at the right end of the melting cylinder 11. A baffle 119 is installed at the right end of the pressure sensor 1113. A piston rod 118 is installed at one end of the baffle 119. The piston rod 118 is connected to the hydraulic pump 117. A perforated plate 1111 is installed at the right end of the baffle 119. A discharge port 1112 is installed at the right end of the perforated plate 1111. Four support columns 121 are installed at the four corners below the machine housing 2. Two support columns 222 are installed below the power unit 10. Six support columns 323 are installed below the machine housing 3.

[0034] The working principle of this invention is as follows: During the operation of the twin-screw extruder, waste plastic bottles are first added to the feed hopper 1. The waste plastic bottles enter the cutting hopper 41 from the feed hopper 1. The control system controls the hydraulic pump 43 to operate. The hydraulic pump 43 pushes the piston rod 44. The two blades 45 on the piston rod 44 cut the waste plastic bottles, separating the bottle caps and bottoms from the bottle body. The hydraulic pump 46 operates, pulling the piston rod 47 to retract. The bottle caps and bottoms fall into the conveying pipe 49 and are discharged from the entire system through the conveying pipe 49. The bottle falls into the crushing chamber 53. Motor 1 51 starts running, and the main shaft of Motor 1 51 rotates, driving the blades 45 on the stirring shaft to rotate, crushing the bottle and label. Valve 1 55 opens. Before the crushed material enters the cleaning chamber 73, blower 6 is started and the wind speed of blower 6 is controlled to remove only the crushed label. Valve 1 77 opens, water pump 74 starts running, and water is injected into the cleaning chamber 73. Motor 2 71 starts running, and the main shaft of Motor 2 71 rotates, driving the stirring blades 711 on the stirring shaft to rotate, causing the crushed material to rotate and be cleaned. After cleaning, valve 2 710 is opened, and the water in the cleaning chamber 73 is discharged from the drain pipe. Valve 2 78 opens, and the cleaned material falls onto the stainless steel mesh conveyor belt 83. Motor 3 81 starts running, driving drum 82 to rotate. Drum 82 drives the stainless steel mesh conveyor belt 83 to rotate to the right. Heating block 1 84 is installed inside the conveyor belt to heat and dry the wet material.

[0035] After being heated and dried, the material enters the storage silo 9 via a conveyor belt. The motor 102 in the power silo 101 operates, and the main shaft of the motor 102 drives the drive gear 103 to rotate. The drive gear 103 meshes with two driven gears 104, which in turn drive the driven gears 104 to rotate. The driven gears 104 then drive the two screws 112 to rotate. The material in the storage silo 9 enters the melting cylinder 11. Heating wires 114 are arranged in a ring on the inner wall of the cylinder 111. The heating wires 114 are installed in a sparse manner on the left end and densely on the right end. This installation method results in a lower temperature at the inlet of the melting cylinder 11 and a higher temperature at the outlet 1112. This installation method prevents blockage during the feeding process. The two screws 112 spirally compress the material and move it towards the outlet 1112. During the movement, the material is heated into a molten state. The molten material then enters the perforated plate 1111 and finally enters the mold through the outlet 1112 to be formed.

[0036] When incompletely molten material moves before the perforated plate 1111, the pressure sensor 1113 detects the pressure change and transmits the signal to the central system. The control system then controls the hydraulic pump 117 to operate, pushing the piston rod 118 to move. The baffle 119 on the piston rod 118 blocks the perforated plate 1111, the valve 1110 opens, the hydraulic pump 1116 operates, and pulls the piston rod 1115 upward. The piston rod 1115 then pulls the baffle 1114 upward. The material is pushed into the return chamber 115 by the screw 112. The heating block 116 in the return chamber 115 reheats the incompletely melted material. Then the valve plate 1110 is opened, the hydraulic pump 117 pulls the piston rod 118 to retract, the baffle 119 retracts, the hydraulic pump 1116 operates to push the piston rod 1115, the piston rod 1115 pushes the baffle 1114 to move downward, and the molten material re-enters the perforated plate 1111, and is then discharged from the outlet 1112.

[0037] It will be apparent to those skilled in the art that the present 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 its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A twin-screw extruder for melting bottle flakes, characterized in that: The twin-screw extruder includes a feed hopper (1), a first casing (2), a second casing (3), a conveying unit (8), a power unit (10), and a melting cylinder (11). The feed hopper (1) is installed on the upper end face of the first casing (2). Inside the first casing (2), a cutting unit (4), a crushing unit (5), and a cleaning unit (7) are installed from top to bottom. There is a positional deviation between the cutting unit (4), the crushing unit (5), and the cleaning unit (7). The first casing (2) and the second casing (3) are connected by the conveying unit (8). The power unit (10) is installed on the left end face of the second casing (3). The melting cylinder (11) is installed inside the second casing (3). The power unit (10) is connected to the melting cylinder (11). The cutting unit (4) includes a cutting chamber (41), a fixing plate (42), a hydraulic pump (43), a piston rod (44), a blade (45), a hydraulic pump (46), a piston rod (47), and a conveying pipe (49). The fixing plate (42) is fixed to the inner wall of the housing (2). The fixing plate (42) is connected to the cutting chamber (41). A support plate (48) is provided below the cutting chamber (41). The support plate (48) is connected to the piston rod (47). The piston rod (47) is connected to the hydraulic pump (46). The hydraulic pump (46) is fixed to the surface of the housing (2). The blade (45) is connected to the piston rod (44). The piston rod (44) is connected to the hydraulic pump (43). The hydraulic pump (43) is fixed to the surface of the housing (2). The conveying pipe (49) is installed below the support plate (48). The inner side of the melting cylinder (11) is provided with a cylinder body (111), and two screws (112) are installed inside the cylinder body (111). A reflux chamber (115) is installed at the right end of the cylinder (111). A valve plate (1110) is provided at the bottom of the reflux chamber (115). A baffle (1114) is provided inside the reflux chamber (115). A piston rod (1115) is provided on the baffle (1114). The piston rod (1115) is connected to a hydraulic pump (1116). A heating block (116) is provided on the side wall of the reflux chamber (115). A heating wire (114) is provided inside the heating block (116).

2. The twin-screw extruder for melting bottle flakes according to claim 1, characterized in that: The crushing unit (5) includes a crushing chamber (53) and a fixing plate (56). The fixing plate (56) is installed on the inner wall of the casing (2). The fixing plate (56) is connected to the crushing chamber (53). A crossbeam (52) is installed above the crushing chamber (53). A motor (51) is installed above the crossbeam (52). A blade (54) is installed on the stirring shaft of the motor (51). A valve plate (55) is installed at the bottom of the crushing chamber (53). A blower (6) is installed below the crushing chamber (53).

3. A twin-screw extruder for melting bottle flakes according to claim 1, characterized in that: The cleaning unit (7) includes a cleaning chamber (73), a fixing plate three (710), a water pump (74), and a water tank (75). The fixing plate three (710) is installed on the inner wall of the casing one (2) and is connected to the cleaning chamber (73). A crossbeam two (72) is installed above the cleaning chamber (73), and a motor two (71) is installed above the crossbeam two (72). A stirring blade (711) is installed on the stirring shaft of the motor two (71). A drain pipe (76) is installed on the side wall of the cleaning chamber (73), and a valve two (78) is installed on the drain pipe (76). One side of the cleaning chamber (73) is connected to the water pump (74) through a pipeline. The water pump (74) is connected to the water tank (75) through a pipeline. A valve one (77) is installed on the pipeline. A valve plate two (79) is installed at the bottom of the cleaning chamber (73).

4. A twin-screw extruder for melting bottle flakes according to claim 1, characterized in that: The conveying unit (8) includes a stainless steel mesh conveyor belt (83) and a motor (81). The stainless steel mesh conveyor belt (83) is installed at the connection between the first (2) and the second (3) of the machine box. A roller (82) is installed inside the stainless steel mesh conveyor belt (83). The main shaft of the motor (81) is connected to the roller (82). A heating block (84) is installed inside the stainless steel mesh conveyor belt (83). A heating wire (114) is installed inside the heating block (84).

5. A twin-screw extruder for melting bottle flakes according to claim 1, characterized in that: The power unit (10) includes a power compartment (101), a drive gear (103), and driven gears (104). The power compartment (101) is installed on the side wall of the second (3) housing. A fourth motor (102) is installed inside the power compartment (101). The main shaft of the fourth motor (102) is connected to the drive gear (103). The drive gear (103) is connected to two driven gears (104) through gear meshing. The screw (112) is connected to the driven gear (104).

6. A twin-screw extruder for melting bottle flakes according to claim 5, characterized in that: The melting cylinder (11) includes a fixing plate four (113), a hydraulic pump three (117), and a valve plate three (1110). The fixing plate four (113) is installed on the bottom end face of the casing two (3). The fixing plate four (113) is connected to the cylinder body (111). The cylinder body (111) is a double-layered cylinder. A heating wire (114) is provided in the interlayer of the cylinder body (111). The heating wire (114) is wound on the cylinder body (111). The heating wires (114) inside the cylinder (111) are sparse on the left and dense on the right. A storage bin (9) is installed on the left end of the cylinder (111). A pressure sensor (1113) is installed on the right end of the cylinder (111). A baffle (119) is installed on the right end of the pressure sensor (1113). A piston rod (118) is installed on one end of the baffle (119). The piston rod (118) is connected to a hydraulic pump (117).

7. A twin-screw extruder for melting bottle flakes according to claim 6, characterized in that: A perforated plate (1111) is installed on the right end of the baffle (119), and a discharge port (1112) is installed on the right end of the perforated plate (1111).

8. A twin-screw extruder for melting bottle flakes according to claim 1, characterized in that: Four support columns (121) are installed at the four corners below the chassis (2), two support columns (122) are installed below the power unit (10), and six support columns (123) are installed below the chassis (3).

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