A multimodal sorting system and a process for purifying recycled plastics

Abstract

This invention belongs to the field of sorting equipment technology, specifically a multimodal sorting system and a process for purifying recycled plastics. It includes a multimodal detection mechanism, which is a combination of a machine vision morphology recognition module, a spectral analysis module, and a density detection module. It also includes a multi-station continuous detection mechanism for continuous detection of PCR materials. This invention installs multiple detection boxes on the circumference of a switching disk, utilizing the continuous periodic rotation of the switching disk to allow the multiple detection boxes to sequentially receive PCR materials and perform detection during the rotation. With a single conveyor belt, multi-station loading and unloading can be achieved, simplifying the equipment structure and effectively reducing the impact of PCR material transport on detection efficiency while shortening the transport distance.

Description

Technical Field

[0001] This invention belongs to the field of sorting equipment technology, specifically a multimodal sorting system and a process for purifying recycled plastics. Background Technology

[0002] PCR refers to reusable plastic raw materials obtained from waste plastics generated in household, commercial, or industrial consumption processes through recycling, sorting, and pretreatment.

[0003] In the field of PCR material production, traditional manual sorting methods are inefficient and labor-intensive, with prolonged operation leading to worker fatigue and resulting in missed detections or misclassifications. To address this, related technologies often utilize multimodal data acquisition systems combined with machine vision technology to achieve automated mechanical inspection of PCR materials. The widespread adoption of automated inspection not only significantly improves the accuracy of PCR material detection, effectively reducing the probability of false positives and missed detections, but also eliminates the need for human intervention, greatly reducing labor and management costs. Furthermore, this multimodal inspection integrates various detection modules such as spectral analysis, density detection, and morphology recognition, enabling comprehensive and accurate identification of key indicators such as the material composition, color, and impurity content of the PCR material. This ensures that each batch of sorted material meets the stringent requirements of subsequent purification processes. PCR materials sorted by this system can effectively reduce the impact of impurities on process stability during subsequent purification processes such as washing, drying, and melt extrusion, significantly improving the mechanical properties and appearance quality of the final PCR material.

[0004] However, in practical applications, it has been found that as the number of detection items increases during multimodal detection, the detection time will inevitably be extended. Furthermore, the detection process and the PCR loading and unloading process are carried out alternately throughout the entire detection process, which leads to a decrease in multimodal sorting efficiency and makes it unsuitable for batch PCR detection environments.

[0005] In view of this, the present invention proposes a multimodal sorting system and a process for purifying recycled plastics to solve the above-mentioned technical problems. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies and solve the above-mentioned technical problems, this invention proposes a multimodal sorting system and a process for purifying recycled plastics.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a multimodal sorting system according to the present invention, including a multimodal detection mechanism, wherein the multimodal detection mechanism is a combination of a machine vision morphology recognition module, a spectral analysis module and a density detection module; It also includes a multi-station continuous testing mechanism, which is used to realize continuous testing of PCR materials. The multi-station continuous testing mechanism includes a conveyor belt, a testing table, a switching plate, a drive motor, a testing box, a switching plate and a discharge box. The conveyor belt is connected to the testing station and is used to transport PCR material onto the testing station. A switching disk is rotatably mounted on the testing platform, and a testing box is fixedly mounted on the switching disk. Each testing box is equipped with a multimodal testing mechanism. A drive motor is fixedly installed on the testing platform, and the output end of the drive motor is fixedly connected to the switching disk; The detection box has a through slot along the diameter of the switching disk, and a switching plate is rotatably installed in the through slot by a switching motor. The discharge box is installed on the testing platform, and the discharge box is coaxially arranged with the switching plate and aligned with the outlet of the through groove.

[0008] Preferably, the detection platform has a surrounding groove located between the switching plate and the conveyor belt. An elastic plate is fixedly installed on the switching plate and located in the gap of the detection box. The elastic plate is used to push the PCR material to move in the surrounding groove.

[0009] Preferably, the bottom wall of the surrounding groove is inclined, and the bottom wall of the surrounding groove is lower on the side facing the detection box. The side of the surrounding groove away from the detection box is fixedly equipped with uniformly distributed injection pipes, and the injection pipes are connected to an external air compressor.

[0010] Preferably, the switching plate is rotatably installed in the through groove, and the edges of the switching plate are fixedly equipped with blocks. In the initial state, the blocks prevent the PCR material in the surrounding groove from moving into the through groove.

[0011] Preferably, it also includes a sorting and discharging mechanism, which is used to sort the PCR material after testing. The sorting and discharging mechanism includes a separating ring plate and a telescopic guide. The partition ring plate is fixedly installed inside the discharge box, and the partition ring plate divides the discharge box into multiple storage chambers nested in sequence; The telescopic guide is fixedly installed on the test box, and the telescopic guide is used to guide the PCR material into different storage chambers.

[0012] Preferably, the telescopic guide includes a telescopic plate, a screw, a meshing nut, a transmission gear, and a gear ring; The telescopic plate is fixedly installed on the detection box, and a meshing nut is fixedly installed on the end of the telescopic plate away from the detection box. The screw is rotatably mounted at the bottom of the detection box, the telescopic plate extends in a direction parallel to the length of the screw, and the engaging nut is helically driven by the screw. The toothed ring is fixedly mounted on the testing platform, and the transmission gear is fixedly mounted on the screw. The transmission gear meshes with the toothed ring for transmission.

[0013] Preferably, the telescopic guide further includes a reset band, a guide frame, a moving rod, and a hydraulic rod; A guide frame is fixedly installed on the bottom side of the telescopic plate facing the detection box. A moving rod is slidably installed inside the guide frame. One end of the reset belt is fixedly installed on the moving rod, and the other end extends and is fixed on the side of the telescopic plate away from the detection box. The engagement nut consists of engagement teeth and a collar. The collar is fixedly installed on the telescopic plate. A hydraulic telescopic groove is provided on the collar. The engagement teeth are installed in the hydraulic telescopic groove by a spring sliding seal. The hydraulic rod is fixedly installed on the movable rod, and the hydraulic rod is electrically connected to the hydraulic telescopic groove. The hydraulic rod is located on the rotation path of the switching plate.

[0014] Preferably, a fixing rod is fixedly installed inside the guide frame, and the middle part of the reset band wraps around the fixing rod and the moving rod multiple times.

[0015] Preferably, the telescopic plate is inclined, the end of the telescopic plate away from the detection box is lower, and the upper surface of the telescopic plate is all smooth.

[0016] A process for refining recycled plastics, the process comprising the following steps: A1: Place the PCR material to be recycled on the conveyor belt and transport it towards the testing station; A2: After the PCR material to be recovered is detected by the multimodal detection mechanism in the detection box, it is guided by the sorting and discharging mechanism and finally enters different storage chambers; A3: Transfer PCR materials with different defects to the reprocessing equipment, and reprocess the PCR materials according to their defect classification.

[0017] The beneficial effects of this invention are as follows: 1. The multimodal sorting system and recycled plastic purification process described in this invention installs multiple detection boxes on the circumferential direction of a switching disk. The continuous periodic rotation of the switching disk causes the multiple detection boxes to receive PCR materials sequentially, and the PCR materials are detected during the rotation. With the transport of materials on a single conveyor belt, multi-station loading and unloading can be achieved. This not only simplifies the structure of the equipment, but also effectively reduces the impact of PCR material transport on detection efficiency when the transport distance is shortened.

[0018] 2. The multimodal sorting system and recycled plastic purification process described in this invention, by setting up a surrounding trough, can discharge and replenish PCR material in the through trough in real time during the periodic rotation of the detection box following the switching disk. Compared with the method of replenishing material only from the conveyor belt, this invention can discharge unqualified PCR material in time and replenish PCR material in the through trough in real time. This not only reduces the detection time wasted by unqualified material, but also reduces the probability of the detection box being idle after the unqualified material is discharged, thereby effectively improving the detection efficiency of PCR material. Attached Figure Description

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Figure 1 This is an overall perspective view of the present invention; Figure 2 It is a 3D assembly diagram of the testing station and the discharge box; Figure 3 It is a 3D assembly diagram of the switching disk and the detection box; Figure 4 It is a three-dimensional assembly view of the detection box and the telescopic plate; Figure 5 This is a 3D view of the sorting and discharging mechanism assembled on the testing box; Figure 6 This is a cross-sectional view of the detection box and the telescopic plate. Figure 7 This is a schematic diagram of the assembly of the screw and the engaging nut; Figure 8 This is a three-dimensional view of the unfolded telescopic plate. Figure 9 This is a process flow diagram of the present invention; In the diagram: 1. Conveyor belt; 2. Inspection table; 21. Switching plate; 22. Inspection box; 23. Drive motor; 24. Through groove; 25. Switching motor; 26. Switching plate; 3. Discharge box; 31. Dividing ring plate; 32. Storage chamber; 4. Circulating groove; 41. Elastic plate; 42. Injection pipe; 43. Air compressor; 5. Telescopic plate; 51. Screw; 52. Gear ring; 53. Transmission gear; 54. Reset belt; 55. Guide frame; 56. Moving rod; 57. Hydraulic rod; 6. Collar; 61. Hydraulic telescopic groove; 62. Meshing teeth; 7. Fixed rod. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0022] like Figures 1 to 9As shown, the multimodal sorting system of the present invention includes a multimodal detection mechanism, which is a combination of a machine vision morphology recognition module, a spectral analysis module and a density detection module; It also includes a multi-station continuous testing mechanism, which is used to realize continuous testing of PCR materials. The multi-station continuous testing mechanism includes a conveyor belt 1, a testing table 2, a switching plate 21, a drive motor 23, a testing box 22, a switching plate 26, and a discharge box 3. The conveyor belt 1 is connected to the testing station 2, and the conveyor belt 1 is used to transport PCR materials onto the testing station 2. Therefore, a switching disk 21 is rotatably installed on the testing table 2, and a testing box 22 is fixedly installed on the switching disk 21. Each testing box 22 is equipped with a multimodal testing mechanism. A drive motor 23 is fixedly installed on the testing station 2, and the output end of the drive motor 23 is fixedly connected to the switching disk 21; The detection box 22 has a through slot 24 along the diameter of the switching disk 21, and a switching plate 26 is rotatably installed in the through slot 24 via a switching motor 25. The discharge box 3 is installed on the testing table 2. The discharge box 3 is coaxially arranged with the switching plate 21 and the discharge box 3 is aligned with the outlet of the through groove 24.

[0023] In the multimodal detection process of PCR materials, the PCR materials are placed in a multi-station continuous detection mechanism. By continuously switching between multiple stations, the detection and loading / unloading are carried out simultaneously, thereby achieving continuous and uninterrupted detection of PCR materials and effectively improving the detection efficiency of PCR materials.

[0024] Specifically, during continuous testing, conveyor belt 1 continuously transports PCR material towards testing platform 2, while drive motor 23 on testing platform 2 rotates continuously. The output of drive motor 23 drives switching disk 21 to move, causing testing box 22 on switching disk 21 to periodically dock with conveyor belt 1. When testing box 22 docks with conveyor belt 1, the PCR material on conveyor belt 1 is transported into the through groove 24 on testing box 22. While rotating with switching disk 21, the multimodal detection mechanism inside testing box 22 performs multimodal detection on the PCR material. In this invention, the multimodal detection process is controlled by a pre-set program. During detection, the order and time of detection items are fixed values. If the current detection item fails to meet the standard, under the control of the pre-set program, switching motor 25 is immediately started, and switching plate 26 pushes... PCR materials are fed from the through-slot 24 to the designated area of ​​the discharge box 3. During the periodic rotation of the switching disc 21 carrying the detection box 22, continuous detection of PCR materials is achieved. Compared with the single-station detection equipment in conventional technology, the conveyor belt 1 needs to stop operating during the detection process until the PCR materials in the detection station are detected before it can be restarted. This invention installs multiple detection boxes 22 in the circumferential direction of the switching disc 21. By utilizing the continuous periodic rotation of the switching disc 21, multiple detection boxes 22 receive PCR materials in sequence and detect the PCR materials during the rotation. With the transportation of one conveyor belt 1, multi-station loading and unloading can be realized. This not only simplifies the structure of the equipment, but also effectively reduces the reduction in detection efficiency caused by the transportation of PCR materials when the transportation distance is shortened.

[0025] In a preferred embodiment of the present invention, the detection stage 2 is provided with a surrounding groove 4, which is located between the switching disk 21 and the conveyor belt 1. An elastic plate 41 is fixedly installed on the switching disk 21, and the elastic plate 41 is located in the gap of the detection box 22. The elastic plate 41 is used to push the PCR material to move in the surrounding groove 4.

[0026] The bottom wall of the surrounding groove 4 is inclined, and the side of the bottom wall of the surrounding groove 4 facing the detection box 22 is lower. The side of the surrounding groove 4 away from the detection box 22 is fixedly installed with uniformly distributed injection pipes 42. The injection pipes 42 are connected to an air compressor 43. The setting of the injection pipes 42 continuously injecting compressed air not only cooperates with the inclined bottom wall of the surrounding groove 4 to facilitate the replenishment of PCR material to the detection box 22, but also continuously cools the detection box 22 with airflow, thereby accelerating the heat dissipation efficiency of the multimodal detection mechanism inside the detection box 22 and reducing the probability of equipment overheating.

[0027] The switching plate 26 is rotatably installed in the through groove 24. Each edge of the switching plate 26 is fixedly equipped with a stop block. In the initial state, the stop block prevents the PCR material in the surrounding groove 4 from moving into the through groove 24.

[0028] Since PCR materials with defects can only be reprocessed after testing, in order to speed up the testing process as much as possible and reduce the waste of testing resources, in this invention, a surrounding groove 4 is provided on the testing station 2. When the conveyor belt 1 transports the PCR materials, the transport efficiency of the conveyor belt 1 is higher than the rotation speed of the testing box 22. Therefore, after the testing box 22 has received all the PCR materials, the excess PCR materials are pushed by the periodically rotating elastic plate 41 and gradually fill the surrounding groove 4, and are evenly arranged in the surrounding groove 4. When a defect is found in the PCR materials in the testing box 22 during the sequential multimodal testing process, the excess PCR materials are then... The switching plate 26 corresponding to the test box 22 is driven by the switching motor 25 under the control of a preset program, discharging the PCR material in the test box 22 to a designated area. At the same time, the PCR material in the surrounding groove 4 corresponding to the through groove 24 on the test box 22 is pushed into the through groove 24 in the test box 22 by the airflow continuously sprayed by the jet pipe 42, and a new round of testing begins. Since the edge of the switching plate 26 is fixedly installed with a stop, only one PCR material can enter the through groove 24 during a single rotation of the switching plate 26, thereby realizing the alternating testing of PCR material in the through groove 24.

[0029] By setting up a surrounding groove 4, the present invention can discharge and replenish PCR material in the through groove 24 in real time during the periodic rotation of the detection box 22 following the switching disk 21. Compared with the method of replenishing material only from the conveyor belt 1, the present invention can discharge unqualified PCR material in time and replenish PCR material in the through groove 24 in real time. This not only reduces the detection time wasted by unqualified material, but also reduces the probability of the detection box 22 being idle after the unqualified material is discharged, thereby effectively improving the detection efficiency of PCR material.

[0030] As a preferred embodiment of the present invention, it further includes a sorting and discharging mechanism for sorting the PCR material after testing. The sorting and discharging mechanism includes a separating ring plate 31 and a telescopic guide. The dividing ring plate 31 is fixedly installed inside the discharge box 3, and the dividing ring plate 31 divides the discharge box 3 into multiple storage chambers 32 arranged in sequence. The telescopic guide is fixedly installed on the test box 22, and the telescopic guide is used to guide the PCR material into different storage chambers 32.

[0031] The telescopic guide includes a telescopic plate 5, a screw 51, a meshing nut, a transmission gear 53, and a toothed ring 52; The telescopic plate 5 is fixedly installed on the detection box 22, and a meshing nut is fixedly installed on the end of the telescopic plate 5 away from the detection box 22. The screw 51 is rotatably mounted at the bottom of the detection box 22, and the telescopic plate 5 extends and retracts in a direction parallel to the length of the screw 51. The engagement nut is screwed into the screw 51 via a helical drive. The toothed ring 52 is fixedly installed on the testing table 2, and the transmission gear 53 is fixedly installed on the screw 51. The transmission gear 53 meshes with the toothed ring 52 for transmission.

[0032] To classify the PCR materials being fed, in this invention, the storage box is divided into multiple storage chambers 32 by a separating ring plate 31. As the detection box 22 rotates with the switching plate 21, when the PCR materials enter the through-slot 24, the multimodal detection mechanism performs multiple tests sequentially under the control of a pre-set program. Simultaneously, the transmission gear 53 meshes with the gear ring 52, causing the screw 51 to rotate. The screw 51, through helical transmission, causes the telescopic plate 5 to gradually extend from its initial contracted state. The extension range of the telescopic plate 5 is proportional to the rotation angle of the detection box 22 and the time it takes for the PCR materials to enter the through-slot 24. When a defect is detected in the PCR materials during the sequential multi-item testing, the end of the telescopic plate 5 is positioned above the corresponding storage chamber 32. Therefore, when the switching motor 25, in conjunction with the switching plate 26, discharges the materials, guided by the telescopic plate 5, the PCR materials fall into the corresponding storage chamber 32, allowing staff to reprocess or transport them to the next process according to their classification.

[0033] The telescopic guide also includes a reset band 54, a guide frame 55, a moving rod 56, and a hydraulic rod 57; A guide frame 55 is fixedly installed on the bottom side of the telescopic plate 5 facing the detection box 22. A moving rod 56 is slidably installed inside the guide frame 55. One end of the reset belt 54 is fixedly installed on the moving rod 56, and the other end extends and is fixed on the side of the telescopic plate 5 away from the detection box 22. The engagement nut is composed of engagement teeth 62 and a collar 6. The collar 6 is fixedly installed on the telescopic plate 5. A hydraulic telescopic groove 61 is provided on the collar 6. The engagement teeth 62 are installed in the hydraulic telescopic groove 61 by spring sliding seal. The hydraulic rod 57 is fixedly installed on the movable rod 56. The hydraulic rod 57 is electrically connected to the hydraulic telescopic groove 61. The hydraulic rod 57 is located on the rotation path of the switching plate 26.

[0034] To ensure that the telescopic plate 5 is in its initial contracted state when the PCR material enters the through-slot 24, the switching plate 26 rotates to first transfer the post-detection PCR material from the through-slot 24 onto the telescopic plate 5. Then, the switching plate 26 presses against the hydraulic rod 57, causing it to extend. The hydraulic rod 57 transmits negative pressure to the hydraulic telescopic groove 61, causing the hydraulic oil in the groove to flow back into the hydraulic rod 57. This causes the meshing teeth 62 to disengage from the screw 51. As the switching plate 26 continues to rotate, the hydraulic rod 57 pulls the moving rod 56, which in turn pulls the reset band 54 and the collar 6. Finally, when new PCR enters the through-slot 24, the telescopic plate 5 contracts back to its initial state. At this point, the switching plate 26 separates from the hydraulic rod 57. Then, under the action of the spring in the hydraulic telescopic groove 61, the meshing teeth 62 re-insert into the thread of the screw 51, so that after the detection program starts, the screw 51 can again drive the meshing nut to move, and the telescopic plate 5 can extend again.

[0035] It should be noted that in this invention, a pipe is integrated in the middle of the reset band 54, and the pipe connects the hydraulic telescopic groove 61 and the hydraulic rod 57. The pipe is preferably an elastic tube with a fixed diameter reinforced by a helical spring.

[0036] A fixing rod 7 is fixedly installed inside the guide frame 55. The middle part of the reset band 54 wraps around the fixing rod 7 and the moving rod 56 multiple times. The way the fixing rod 7 and the reset band 54 are wrapped around each other makes it easy for the reset band 54 to pull the engaging nut to move a long distance during the small-amplitude movement of the moving rod 56.

[0037] The telescopic plate 5 is inclined, with the end of the telescopic plate 5 furthest from the detection box 22 being lower, and the upper surface of the telescopic plate 5 being a smooth surface, which facilitates the rapid sliding of PCR material on the telescopic plate 5.

[0038] A process for refining recycled plastics, the process comprising the following steps: A1: Place the PCR material to be recycled on conveyor belt 1 and transport it from conveyor belt 1 to the testing station 2; A2: After being tested by the multimodal detection mechanism in the detection box 22, the PCR material to be recovered is guided by the sorting and discharging mechanism and finally enters different storage chambers 32; A3: Transfer PCR materials with different defects to the reprocessing equipment, and reprocess the PCR materials according to their defect classification.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multimodal sorting system, comprising a multimodal detection mechanism, wherein the multimodal detection mechanism is a combination of a machine vision morphology recognition module, a spectral analysis module, and a density detection module; Its features are: It also includes a multi-station continuous testing mechanism, which is used to realize continuous testing of PCR materials. The multi-station continuous testing mechanism includes a conveyor belt (1), a testing table (2), a switching plate (21), a drive motor (23), a testing box (22), a switching plate (26), and a discharge box (3). The conveyor belt (1) is connected to the testing station (2), and the conveyor belt (1) is used to transport PCR material to the testing station (2); A switching disk (21) is rotatably mounted on the detection platform (2), and a detection box (22) is fixedly mounted on the switching disk (21). Each detection box (22) is equipped with a multimodal detection mechanism. A drive motor (23) is fixedly installed on the testing platform (2), and the output end of the drive motor (23) is fixedly connected to the switching disk (21); The detection box (22) has a through groove (24) along the diameter direction of the switching disk (21), and a switching plate (26) is rotatably installed in the through groove (24) by a switching motor (25). The discharge box (3) is installed on the testing table (2), the discharge box (3) is coaxially arranged with the switching plate (21), and the discharge box (3) is aligned with the outlet of the through groove (24); The detection platform (2) is provided with a surrounding groove (4), which is located between the switching plate (21) and the conveyor belt (1). An elastic plate (41) is fixedly installed on the switching plate (21), which is located in the gap of the detection box (22). The elastic plate (41) is used to push the PCR material to move in the surrounding groove (4). The bottom wall of the surrounding groove (4) is inclined, and the bottom wall of the surrounding groove (4) is lower on the side facing the detection box (22). The side of the surrounding groove (4) away from the detection box (22) is fixedly equipped with uniformly distributed injection pipes (42), and the injection pipes (42) are connected to an air compressor (43). The switching plate (26) is rotatably installed in the through groove (24). The edges of the switching plate (26) are fixedly equipped with blocks. In the initial state, the blocks prevent the PCR material in the surrounding groove (4) from moving into the through groove (24).

2. The multimodal sorting system according to claim 1, characterized in that: It also includes a sorting and discharging mechanism, which is used to sort the PCR material after testing. The sorting and discharging mechanism includes a separating ring plate (31) and a telescopic guide. The partition ring plate (31) is fixedly installed inside the discharge box (3), and the partition ring plate (31) divides the discharge box (3) into multiple storage chambers (32) arranged in sequence. The telescopic guide is fixedly installed on the test box (22) and is used to guide the PCR material into different storage chambers (32).

3. The multimodal sorting system according to claim 2, characterized in that: The telescopic guide includes a telescopic plate (5), a screw (51), a meshing nut, a transmission gear (53), and a toothed ring (52). The telescopic plate (5) is fixedly installed on the detection box (22), and a meshing nut is fixedly installed at the end of the telescopic plate (5) away from the detection box (22); The screw (51) is rotatably mounted on the bottom of the detection box (22), the telescopic plate (5) has a telescopic direction parallel to the length direction of the screw (51), and the meshing nut is screwed to drive the screw (51). The gear ring (52) is fixedly installed on the testing table (2), and the transmission gear (53) is fixedly installed on the screw (51). The transmission gear (53) meshes with the gear ring (52) for transmission.

4. The multimodal sorting system according to claim 3, characterized in that: The telescopic guide also includes a reset band (54), a guide frame (55), a moving rod (56), and a hydraulic rod (57). A guide frame (55) is fixedly installed on the bottom side of the telescopic plate (5) facing the detection box (22). A moving rod (56) is slidably installed inside the guide frame (55). One end of the reset belt (54) is fixedly installed on the moving rod (56), and the other end extends and is fixed on the side of the telescopic plate (5) away from the detection box (22). The engagement nut is composed of engagement teeth (62) and a collar (6). The collar (6) is fixedly installed on the telescopic plate (5). A hydraulic telescopic groove (61) is provided on the collar (6). The engagement teeth (62) are installed in the hydraulic telescopic groove (61) by spring sliding seal. The hydraulic rod (57) is fixedly installed on the movable rod (56), and the hydraulic rod (57) is connected to the hydraulic telescopic groove (61). The hydraulic rod (57) is located on the rotation path of the switching plate (26).

5. A multimodal sorting system according to claim 4, characterized in that: A fixed rod (7) is fixedly installed inside the guide frame (55), and the middle part of the reset band (54) wraps around the fixed rod (7) and the moving rod (56) multiple times.

6. A multimodal sorting system according to claim 5, characterized in that: The telescopic plate (5) is inclined, and the end of the telescopic plate (5) away from the detection box (22) is lower. The upper surface of the telescopic plate (5) is a smooth surface.

7. A process for refining recycled plastics, characterized in that: The purification process uses a multimodal sorting system as described in claim 6, and the purification process includes the following steps: A1: Place the PCR material to be recycled on the conveyor belt (1) and transport it from the conveyor belt (1) to the testing station (2); A2: After the PCR material to be recovered is detected by the multimodal detection mechanism in the detection box (22), it is guided by the sorting and discharging mechanism and finally enters different storage chambers (32); A3: Transfer PCR materials with different defects to the reprocessing equipment, and reprocess the PCR materials according to their defect classification.

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