Mulching film recycling process

Abstract

The invention relates to a mulching film recovery treatment process. The process comprises the following steps: S1, screening and removing impurities; s2, crushing; s3, primary dry rubbing and impurity removal; s4, centrifugal impurity removal; s5, sorting and removing impurities; and S6, carrying out secondary dry rubbing and collecting. Heavy impurities mixed in the impurity-containing mulching film can be removed after the recycled impurity-containing mulching film is subjected to screening and impurity removal through the screening machine, crushing into blocks through the crushing machine and primary dry rubbing and impurity removal through the first dry rubbing machine in sequence, and light impurities mixed in the impurity-containing mulching film can be removed after the recycled impurity-containing mulching film is subjected to impurity removal through the cyclone separator, the first sorting machine and the second sorting machine in sequence. And finally, the mulching film subjected to impurity removal is discharged and collected after being subjected to secondary dry twisting through the second dry twisting machine and can be reused, water resources are not needed in the whole technological process, waste of the water resources is avoided, the water resources are saved, impurity removal in the whole technological process is more complete and thorough, the impurity removal efficiency is higher, the automation degree is higher, manpower is saved, and use is more convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling and reuse of plastic films, and specifically refers to a plastic film recycling and treatment process. Background Art

[0002] The technology of plastic film mulching cultivation has become an important means to ensure agricultural water conservation, stable production and high yield, and has played a huge role in promoting farmers' income increase, agricultural production increase and the adjustment of agricultural planting structure. With the wide application of plastic film mulching cultivation technology on a large scale, the many advantages of plastic film such as heat preservation, water conservation and fertilizer conservation can be fully exerted, effectively improving the land output rate. However, since the existing plastic films are basically made of PE materials and are not easily degraded, white pollution will be formed when they remain in the soil. Therefore, it is necessary to recycle and treat waste plastic films.

[0003] After the waste plastic films are recycled, they are mixed with heavy impurities such as caked soil and stones, as well as light impurities such as crop residues and crop straws. At present, the water washing separation technology is adopted after the plastic films are recycled. First, the plastic films recovered from the farmland are crushed into pieces by a crusher, and then rinsed in a rinsing tank. During the rinsing process, some impurities with a larger density (such as soil blocks and stones) can sink to the bottom of the tank for separation, and the separated plastic films are then dried by a dehydrator.

[0004] There are two deficiencies in the existing water washing separation technology: one is that usually, the plastic films are mixed with light impurities such as straws, and this part of the impurities cannot sink to the bottom of the water, and it is not easy to be separated by rinsing, and the impurity removal is not thorough and the efficiency is low; the other is that the existing water washing method consumes a large amount of water, resulting in waste of water resources, and it is also impossible to achieve continuous automatic control, which is time-consuming and laborious and inconvenient to use. Summary of the Invention

[0005] In view of the deficiencies of the existing technology, the present invention provides a plastic film recycling and treatment process, which does not require water washing separation, can efficiently separate impurities such as soil blocks, stones and straws in the plastic films, is convenient to use with automatic control, and has higher efficiency.

[0006] The present invention is realized through the following technical solutions. A plastic film recycling and treatment process includes the following steps: S1 Screening and impurity removal: The recycled plastic films containing impurities are sent into a screening machine for preliminary screening and impurity removal treatment to screen out heavy impurities in the plastic films containing impurities; S2 Crushing: The plastic films containing impurities after screening and impurity removal are sent into a crusher for crushing treatment into plastic film pieces containing impurities, so as to reduce the volume of the plastic films and the lumpy impurities and reduce the covering area of the plastic films on the impurities; S3 Primary dry rubbing and impurity removal: The plastic film pieces containing impurities are sent into a first dry rubbing machine for primary dry rubbing and impurity removal treatment. Through the rubbing of the first dry rubbing machine, the heavy impurities adhered to the plastic film pieces containing impurities are separated and discharged, forming a mixture of light impurities that can flow with the air flow and the plastic film pieces; S4 Centrifugal impurity removal: After the first dry rubbing impurity removal, the mixture of light impurities and plastic film pieces enters the cyclone separator under the drive of the suction air flow provided by the material fan for centrifugal impurity removal treatment. During the centrifugation process, the light impurities with greater inertia are separated and fall, while the light impurities with smaller inertia and the plastic film pieces continue to flow out following the suction air flow; S5 Sorting impurity removal: The plastic film and the light impurities with smaller inertia after centrifugal impurity removal enter the sorting unit under the drive of the suction air flow. The sorting unit conducts sorting impurity removal treatment on the light impurities with smaller inertia to completely separate the light impurities, and the plastic film pieces continue to flow out following the suction air flow; S6 Second dry rubbing and collection: The plastic film after sorting impurity removal enters the material fan under the drive of the suction air flow. The air flow sent by the material fan sends the plastic film pieces into the second dry rubbing machine for second dry rubbing treatment and then discharges and collects them. The plastic film undergoes second dry rubbing to further ensure that there are no longer any impurities mixed in, guaranteeing the impurity removal effect.

[0007] In this scheme, the impure ground film is first screened by a screening machine. About 70% of the heavy debris such as soil blocks and stones that are easy to separate in the impure ground film can be removed after preliminary screening. Then, the impure ground film after the initial screening is sheared and crushed by a crusher to obtain impure ground film sheets. Since the block-shaped impure ground film is small in size, the coverage area of ​​the ground film on impurities is reduced, and it is easier to unfold when kneaded by the subsequent first dry rubbing machine, so that the heavy debris inside is easy to separate. In addition, the impure ground film is more dispersed after being broken, and it is not easy to gather into clumps during the rubbing process. Each impure ground film sheet can be fully contacted and rubbed with the rubbing mechanism of the dry rubbing machine, so the dry rubbing impurity removal effect is better and more efficient. In addition, since the impure ground film sheet is lighter in weight, after the heavy debris is separated, it is also easier to be extracted by the subsequent exhaust air flow, so that the subsequent light debris separation operation can be realized. The impure ground film sheet is dry-rubbed once in the first dry-rubbing machine to separate the heavy impurities that are difficult to separate, thereby obtaining a thin ground film sheet and a mixture of light impurities such as crop residues and crop straw. The material fan provides an exhaust airflow to the cyclone separator and the sorting unit, thereby driving the light impurities and ground film sheet to enter the cyclone separator first. Since the weight of the light impurities is greater than that of the ground film, a large part of the light impurities with large inertia are thrown to the wall of the device under the centrifugal action, thereby losing the inertia and falling down to achieve separation. The remaining small amount of light impurities and ground film sheets with small inertia continue to follow the exhaust airflow into the sorting unit for further separation, so as to achieve complete separation and removal of light impurities. Finally, only the ground film sheet is sent to the material fan with the exhaust airflow, and the ground film sheet is sent to the second dry-rubbing machine by the air supply airflow. After the second dry-rubbing, it is discharged and collected, and can be reused. The second dry-rubbing further ensures that there is no more mixed impurities to ensure the impurity removal effect. The entire impurity removal process of this process does not require the use of water resources, thereby avoiding the waste of water resources and saving water resources. The impurity removal process separates and removes heavy impurities and light impurities from the beginning to the end, making the impurity removal more complete and thorough, and the impurity removal efficiency is higher.

[0008] As an optimization, the feed port of the screening machine is connected to the first conveyor, the discharge port of the screening machine is connected to the feed port of the crusher through the second conveyor, and the discharge port of the crusher is connected to the feed port of the first dry rubbing machine through the third conveyor. When using this optimization scheme, personnel only need to place the impure ground film on the first conveyor, and the screening machine, crusher and first dry rubbing machine are automatically transported by the conveyor. The first dry rubbing machine, cyclone separator, sorting unit and second dry rubbing machine drive the material to flow backward through the suction air flow provided by the material fan. Therefore, the entire process does not require human participation, and the material can automatically move backward to perform the corresponding operation. The degree of automation is higher, saving manpower and material resources, and it is more convenient to use.

[0009] As an optimization, the sorting machine unit includes a first sorting machine and a second sorting machine, the air outlet of the cyclone separator is connected to the air inlet of the first sorting machine through the second air duct, the air outlet of the first sorting machine is connected to the air inlet of the second sorting machine through the third air duct, and the air outlet of the second sorting machine is connected to the air inlet of the material fan through the fourth air duct. The sorting machine unit of this optimization scheme is equipped with two sorting machines to separate and remove a small amount of light debris with small inertia. After two sortings, it can be ensured that the light debris can be completely separated, thereby improving the impurity removal effect.

[0010] As an optimization, the first sorting machine and the second sorting machine both include a sorting box, the side wall of the sorting box is provided with an air inlet, the top of the sorting box is provided with an air outlet, and the inner walls on both sides of the sorting box are staggered with multiple guide plates, and the multiple guide plates are located between the air inlet and the air outlet. After the lightweight debris and ground film with smaller inertia enter the sorting box, they flow from bottom to top driven by the exhaust airflow, and flow through multiple guide plates during the upward flow. Since the weight of the lightweight debris is still greater than the weight of the ground film, the lightweight debris loses its inertia when it hits the guide plate, and thus falls downward and separates under the action of its own weight, while the ground film with light weight continues to flow upward with the airflow and is discharged from the air outlet.

[0011] As an optimization, the air outlet of the material blower is connected to the feed port of the second dry rubbing machine through a pressure relief pipe. This optimization scheme avoids excessive pressure of the air supply airflow output by the material blower, which directly blows the ground film out of the second dry rubbing machine, thereby losing the secondary dry rubbing effect.

[0012] As an optimization, the first dry rubbing machine and the second dry rubbing machine both include a frame, a dry rubbing box fixed on the frame, and a rubbing mechanism, the dry rubbing box is a U-shaped structure and extends in the horizontal direction, the horizontal ends and the top of the dry rubbing box are closed, the bottom of the dry rubbing box is provided with a debris discharge hole, and the two ends of the dry rubbing box are respectively provided with a feed inlet and a discharge port, and the rubbing mechanism includes a rotating shaft rotatably arranged in the dry rubbing box, the rotating shaft extends along the length direction of the dry rubbing box, and a spiral rubbing plate is arranged around the outer wall of the rotating shaft, and the outer diameter of the spiral rubbing plate is adapted to the inner diameter of the dry rubbing box. In this optimization scheme, the impure ground film sheet enters the dry rubbing box through the feed inlet, and the impure ground film sheet is driven to move toward the discharge port by the rotation of the spiral rubbing plate. While moving, the spiral rubbing plate rubs and rubs the impure ground film sheet, so that the soil and stones wrapped in the ground film are peeled off, and the soil blocks adhering to the ground film also fall off during the rubbing process and are discharged from the debris discharge holes, thereby completely separating the heavy debris.

[0013] As an optimization, a plurality of axial kneading plates are evenly distributed along the circumference of the rotating shaft, and the axial kneading plates extend along the length direction of the rotating shaft and are connected to the spiral kneading plates. In this optimization scheme, the axial kneading plates perform transverse kneading to improve the kneading efficiency and kneading effect, thereby improving the separation effect of heavy debris.

[0014] As an optimization, the height of the axial rubbing plate is less than that of the spiral rubbing plate. This optimization enables the spiral rubbing plate to contact the impurity-containing plastic film, thereby driving the impurity-containing plastic film to move.

[0015] As an optimization, the screening machine and the crusher are respectively connected to a dust collector through a first dust exhaust pipe and a second dust exhaust pipe. This optimization sucks the dust generated during the operation of the screening machine and the crusher through the dust collector, avoiding the overflow of dust and protecting the working environment.

[0016] The beneficial effects of the present invention are as follows: The impurity-containing plastic film can remove the heavy impurities mixed in the impurity-containing plastic film after passing through the screening machine for impurity removal, the crusher for crushing into pieces, and the first dry rubbing machine for primary dry rubbing and impurity removal in sequence. Then, after passing through the cyclone separator, the first separator, and the second separator in sequence, the light impurities mixed in the impurity-containing plastic film can be removed. Finally, the plastic film after impurity removal treatment is discharged and collected after being secondarily dry rubbed by the second dry rubbing machine, and can be reused. The entire process does not require the use of water resources, thereby avoiding the waste of water resources and saving water resources. The impurity removal in the entire process is more complete and thorough, the impurity removal efficiency is higher, and the degree of automation is higher, saving manpower and being more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic process flow diagram of the present invention; Figure 2 is a schematic diagram of the process production line of the present invention; Figure 3 is a schematic diagram of the internal structure of the sorting box; Figure 4 is a front view of the internal structure of the dry rubbing box; Figure 5 is a side view of the internal structure of the dry rubbing box; Figure 6 is a top view of the internal structure of the dry rubbing box As shown in the figure: 1. Screening machine, 2. Crusher, 3. First dry rubbing machine, 4. Cyclone separator, 5. Sorting unit, 51. First separator, 52. Second separator, 6. Material blower, 7. Second dry rubbing machine, 8. First conveyor, 9. Second conveyor, 10. Third conveyor, 11. Pressure relief pipeline, 12. First dust exhaust pipe, 13. Dust collector, 14. Second dust exhaust pipe, 15. First air duct, 16. Second air duct, 17. Third air duct, 18. Fourth air duct, 53. Sorting box, 54. Deflector, 101. Frame, 102. Dry rubbing box, 103. Rotating shaft, 104. Spiral rubbing plate, 105. Axial rubbing plate, 106. Impurity discharge hole, 107. Rubbing bump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To clearly illustrate the technical features of this solution, the following elaborates on this solution through specific embodiments.

[0019] As Figures 1 to 6 shown, a plastic film recycling process includes the following steps: S1 Screening and impurity removal: The recycled impurity-containing plastic film is fed into a screening machine 1 for preliminary screening and impurity removal to screen out heavy impurities in the impurity-containing plastic film; S2 Crushing: The impurity-containing plastic film after screening and impurity removal is fed into a crusher 2 for crushing into impurity-containing plastic film pieces, reducing the volume of the plastic film and massive impurities and shrinking the covering area of the plastic film on the impurities; S3 First dry rubbing and impurity removal: The impurity-containing plastic film pieces are fed into a first dry rubbing machine 3 for first dry rubbing and impurity removal. Through the rubbing of the first dry rubbing machine 3, the heavy impurities adhered to the impurity-containing plastic film pieces are separated and discharged, forming a mixture of light impurities that can flow with the air and plastic film pieces; S4 Centrifugal impurity removal: The mixture of light impurities and plastic film pieces after the first dry rubbing and impurity removal is driven by the suction air flow provided by a material blower 6 into a cyclone separator 4 for centrifugal impurity removal. During the centrifugal process, the light impurities with greater inertia are separated and fall, while the light impurities with smaller inertia and the plastic film pieces continue to flow out following the suction air flow; S5 Sorting and impurity removal: The plastic film and the light impurities with smaller inertia after centrifugal impurity removal are driven by the suction air flow into a sorting unit 5. Through the sorting unit 5 for sorting and impurity removal of the light impurities with smaller inertia, the light impurities are completely separated, and the plastic film pieces continue to flow out following the suction air flow; S6 Second dry rubbing and collection: The plastic film after sorting and impurity removal is driven by the suction air flow into the material blower 6. The plastic film pieces are sent into a second dry rubbing machine 7 by the blowing air flow of the material blower 6 for second dry rubbing treatment and then discharged and collected. The plastic film undergoes second dry rubbing to further ensure that there are no longer any impurities mixed in, guaranteeing the impurity removal effect.

[0020] The recycling process of the present invention is used for impurity removal treatment of the impurity-containing plastic film recycled from farmland. The impurity-containing plastic film includes plastic film, heavy impurities mixed in the plastic film, and light impurities. The heavy impurities include soil blocks adhered to the plastic film and stones covered in the plastic film, and the light impurities include crop residues and straws covered in the plastic film.

[0021] Specifically, the feed inlet of the screening machine 1 is connected to a first conveyor 8, the discharge outlet of the screening machine 1 is connected to the feed inlet of the crusher 2 through a second conveyor 9, and the discharge outlet of the crusher 2 is connected to the feed inlet of the first dry rubbing machine 3 through a third conveyor 10.

[0022] During operation, the impurity-containing plastic film recovered in step S1 is sent into the screening machine 1 by the first conveyor 8 for preliminary screening and impurity removal. The impurity-containing plastic film after screening and impurity removal in step S2 is sent into the crusher 2 by the second conveyor 9 for crushing. In step S3, the plastic film pieces are sent into the first dry rubbing machine 3 by the third conveyor 10 for primary dry rubbing and impurity removal. After the pre-operation is completed, the conveying can be automatically carried out backward without manual participation, greatly improving the automation degree.

[0023] Specifically, the sorting unit 5 includes a first sorting machine 51 and a second sorting machine 52. In this embodiment, the discharge port of the first dry rubbing machine 3 is connected to the air inlet of the cyclone separator 4 through the first air duct 15. The air outlet of the cyclone separator 4 is connected to the air inlet of the first sorting machine 51 through the second air duct 16. The air outlet of the first sorting machine 51 is connected to the air inlet of the second sorting machine 52 through the third air duct 17. The air outlet of the second sorting machine 52 is connected to the air inlet of the material blower 6 through the fourth air duct 18.

[0024] The first dry rubbing machine 3, the cyclone separator 4, the first sorting machine 51, the second sorting machine 52 and the material blower 6 are sequentially connected through each air duct. During operation, the material blower 6 at the tail end draws air, and the drawn air flow flows through the first air duct 15, the cyclone separator 4, the second air duct 16, the first sorting machine 51, the third air duct 17, the second sorting machine 52, and the fourth air duct 18 in sequence from the discharge port of the first dry rubbing machine 3 and then flows into the material blower 6, realizing the pumping of the plastic film pieces and light impurities after primary dry rubbing and impurity removal.

[0025] Specifically, the air outlet of the material blower 6 is connected to the feed inlet of the second dry rubbing machine 7 through the pressure relief pipeline 11. The air pressure of the air supply flow is reduced through the pressure relief pipeline 11 to prevent the air supply flow pressure output by the material blower from being too large and directly blowing the plastic film pieces out of the second dry rubbing machine, thus losing the secondary dry rubbing effect.

[0026] In this embodiment, the screening machine 1 adopts a drum screening machine. The drum of the drum screening machine drives the impurity-containing plastic film to roll during rotation, so as to separate heavy impurities such as soil blocks and stones that are easily separated in the impurity-containing plastic film, and the screening effect is better.

[0027] Preferably, the screening machine 1 and the crusher 2 are respectively connected to a dust collector 13 through a first dust exhaust pipe 12 and a second dust exhaust pipe 14. A large amount of dust will be generated when the screening machine 1 and the crusher 2 are operating. The dust in the screening machine 1 and the crusher 2 is absorbed and removed by the dust suction fan of the dust collector 13 to avoid dust overflow and protect the operating environment.

[0028] In this embodiment, the first sorting machine 51 and the second sorting machine 52 have the same structure. Both the first sorting machine 51 and the second sorting machine 52 include a sorting box 53. A central part of the side wall of the sorting box 53 is provided with an air inlet, and the top of the sorting box 53 is provided with an air outlet. A plurality of guide plates 54 are staggered and distributed on the opposite inner walls of the sorting box 53, and the plurality of guide plates 54 are located between the air inlet and the air outlet. After the light impurities and plastic film pieces with smaller mass enter the sorting box, they flow upward under the drive of the suction air flow. Due to the staggered distribution of the guide plates, through the guiding of the suction air flow by the plurality of guide plates, the light impurities and plastic film pieces swing left and right during the upward movement and contact and collide with each layer of guide plates. Through the collision, the impurities adhering to the plastic film pieces are shaken off. After the impurities collide with the guide plates, they fall downward, and the plastic film pieces continue to flow upward with the air flow and are discharged from the air outlet.

[0029] In this embodiment, both the first dry rubbing machine 3 and the second dry rubbing machine 7 include a frame 101, a dry rubbing box 102 fixedly arranged on the frame 101, and a rubbing mechanism. The dry rubbing box 102 has a U-shaped structure and extends in the horizontal direction. The horizontal two ends and the top of the dry rubbing box 102 are both closed. A waste discharge hole 106 is opened at the bottom of the dry rubbing box 102, and a feed inlet and a discharge outlet are respectively arranged at the two ends of the dry rubbing box 102. The rubbing mechanism includes a rotating shaft 103 rotatably arranged in the dry rubbing box 102. The rotating shaft 103 extends along the length direction of the dry rubbing box 102. A driving motor for driving the rotating shaft 103 to rotate is arranged on the outer wall of the dry rubbing box 102. A spiral rubbing plate 104 is circumferentially arranged on the outer wall of the rotating shaft 103, and the outer diameter of the spiral rubbing plate 104 is adapted to the inner diameter of the dry rubbing box 102. A plurality of axial rubbing plates 105 are circumferentially and evenly distributed on the rotating shaft 103. The axial rubbing plates 105 extend along the length direction of the rotating shaft 103 and are connected to the spiral rubbing plate 104. The height of the axial rubbing plate 105 is less than the height of the spiral rubbing plate 104. In this embodiment, rubbing bumps 107 are further arranged on the inner wall of the bottom of the dry rubbing box 102 to improve the rubbing effect.

[0030] By driving the rotating shaft to rotate through the driving motor, the spiral rubbing plate 104 drives the plastic film pieces containing impurities to move from the bottom of the dry rubbing box 102 towards the discharge outlet. During the moving process, the spiral rubbing plate 104 and the axial rubbing plate 105 cooperate with the rubbing bumps 107 at the bottom of the dry rubbing box to frictionally rub the plastic film pieces containing impurities, so that the plastic film pieces are unfolded. The stones wrapped in the plastic film pieces are peeled off, and the soil blocks adhering to the plastic film pieces are also crushed and fall off during the rubbing process, and are discharged from the waste discharge hole, thereby separating the heavy impurities.

[0031] Working principle: The plastic film containing impurities first passes through the screening machine 1 for preliminary screening. About 70% of the easily separable heavy impurities in the plastic film containing impurities can be removed through the preliminary screening.

[0032] Then, the impurity-containing plastic film after primary screening is sheared and crushed by the crusher 2 to obtain impurity-containing plastic film pieces. Since the volume of the blocky impurity-containing plastic film is small, the covering area of the plastic film on the impurities is reduced, and it is easier to unfold during the subsequent rubbing in the first rubbing machine 3, making it easier to separate the internal soil clods and stones. Moreover, after the impurity-containing plastic film is crushed, it is more dispersed and not easily agglomerated during the rubbing process. Each impurity-containing plastic film piece can be fully contacted and rubbed with the rubbing mechanism of the first rubbing machine 3, so the impurity removal effect by dry rubbing is better and the efficiency is higher. Also, because the impurity-containing plastic film pieces are lighter in mass, after the heavy impurities are completely separated, they are more easily extracted by the subsequent suction air flow, enabling the subsequent separation operation of light impurities to be realized.

[0033] The impurity-containing plastic film pieces are dry-rubbed once by the first rubbing machine 3 to completely separate the heavy impurities, leaving only light impurities such as crop residues and crop straws and the plastic film pieces.

[0034] The material blower 6 provides a suction air flow to the cyclone separator 4 and the sorting unit 5, thereby driving the light impurities and the plastic film pieces to first enter the cyclone separator 4. Since the weight of the light impurities is greater than that of the plastic film pieces, a large part of the heavier light impurities are thrown towards the wall of the separator under the centrifugal force, thus losing the inertial force and falling downward to achieve separation.

[0035] The remaining small amount of lighter light impurities and the plastic film pieces continue to follow the suction air flow into the sorting unit 5 for further separation to achieve complete separation and impurity removal of the light impurities. Finally, only the plastic film pieces follow the suction air flow to the material blower 6 and are sent to the second rubbing machine 7 through the blowing air flow, and are discharged and collected after secondary rubbing, and can be reused again.

[0036] Of course, the above description is not limited to the above examples. The technical features not described in the present invention can be realized by or adopted from the prior art, and will not be elaborated here; the above embodiments and the accompanying drawings are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. The present invention has been described in detail with reference to the preferred embodiments. Those of ordinary skill in the art should understand that any changes, modifications, additions, or substitutions made by those of ordinary skill in the technical field within the scope of the essence of the present invention do not depart from the purpose of the present invention and should also fall within the scope of the claims of the present invention.

Claims

1. A process for recycling and treating plastic mulch films, characterized in that, The following steps are involved: S1 Screening and impurity removal: The recovered impure ground film is sent to the screening machine (1) for preliminary screening and impurity removal to screen out the heavy impurities in the impure ground film; S2 Crushing: The impure ground film after screening and impurity removal is sent to the crusher (2) for crushing into impurity ground film flakes, so that the volume of the ground film and block impurities is reduced, and the coverage area of ​​the ground film on the impurities is reduced; S3: primary dry rubbing and impurity removal: the impure ground film sheet is sent to the first dry rubbing machine (3) for primary dry rubbing and impurity removal treatment. The first dry rubbing machine (3) rubs the impurity-containing ground film sheet so that the heavy impurities adhering to the impurity-containing ground film sheet are separated and discharged, thereby forming a mixture of light impurities and the ground film sheet that can flow with the air flow; S4 Centrifugal impurity removal: After the first dry rubbing and impurity removal, the mixture of light impurities and ground film sheets is driven by the exhaust airflow provided by the material fan (6) and enters the cyclone separator (4) for centrifugal impurity removal. During the centrifugal process, the light impurities with greater inertia are separated and fall, while the light impurities with smaller inertia continue to flow with the ground film sheets and are discharged with the exhaust airflow; S5 Sorting and removing impurities: The ground film and light impurities with small inertia after centrifugal impurity removal enter the sorting unit (5) driven by the exhaust airflow. The light impurities with small inertia are sorted and removed by the sorting unit (5), so that the light impurities are completely separated, and the ground film pieces continue to flow with the exhaust airflow and are discharged; S6 Secondary dry rubbing and collection: The ground film after sorting and impurity removal enters the material fan (6) driven by the exhaust air flow. The ground film pieces are sent to the second dry rubbing machine (7) by the supply air flow of the material fan (6) for secondary dry rubbing and collection. The ground film is further ensured to be free of any impurities after the secondary dry rubbing, thereby ensuring the impurity removal effect.

2. The plastic film recycling and treatment process according to claim 1, characterized in that: The feed port of the screening machine (1) is connected to a first conveyor (8), the discharge port of the screening machine (1) is connected to the feed port of the crusher (2) via a second conveyor (9), and the discharge port of the crusher (2) is connected to the feed port of the first dry rubbing machine (3) via a third conveyor (10).

3. The plastic film recycling and treatment process according to claim 1, characterized in that: The sorting machine group (5) comprises a first sorting machine (51) and a second sorting machine (52); the air outlet of the cyclone separator (4) is connected to the air inlet of the first sorting machine (51) via a second air duct (16); the air outlet of the first sorting machine (51) is connected to the air inlet of the second sorting machine (52) via a third air duct (17); and the air outlet of the second sorting machine (52) is connected to the air inlet of the material fan (6) via a fourth air duct (18).

4. The plastic film recycling and treatment process according to claim 3, characterized in that: The first sorting machine (51) and the second sorting machine (52) both comprise a sorting box (53), an air inlet being provided in the middle of a side wall of the sorting box (53), an air outlet being provided at the top of the sorting box (53), and a plurality of guide plates (54) being staggeredly distributed on inner walls on two opposite sides of the sorting box (53), the plurality of guide plates being located between the air inlet and the air outlet.

5. The plastic film recycling and treatment process according to claim 1, characterized in that: The air outlet of the material blower (6) is connected to the feed inlet of the second dry-rubbing machine (7) via a pressure relief pipe (11).

6. The plastic film recycling and treatment process according to claim 1, characterized in that: The first dry rubbing machine (3) and the second dry rubbing machine (7) both include a frame (101), a dry rubbing box (102) fixedly arranged on the frame (101), and a rubbing mechanism. The dry rubbing box (102) is of a U-shaped structure and extends in the horizontal direction. The horizontal two ends and the top of the dry rubbing box (102) are both closed. A dust discharging hole (106) is formed in the bottom of the dry rubbing box (102). A feed inlet and a discharge outlet are respectively arranged at the two ends of the dry rubbing box (102). The rubbing mechanism includes a rotating shaft (103) rotatably arranged in the dry rubbing box (102). The rotating shaft (103) extends along the length direction of the dry rubbing box (102). A spiral rubbing plate (104) is circumferentially arranged around the outer wall of the rotating shaft (103). The outer diameter of the spiral rubbing plate (104) is adapted to the inner diameter of the dry rubbing box (102).

7. The plastic film recycling and treatment process according to claim 6, characterized in that: A plurality of axial rubbing plates (105) are circumferentially and evenly distributed on the rotating shaft (103). The axial rubbing plates (105) extend along the length direction of the rotating shaft (103) and are connected with the spiral rubbing plates (104).

8. The plastic film recycling and treatment process according to claim 7, characterized in that: The height of the axial rubbing plate (105) is less than the height of the spiral rubbing plate (104).

9. The plastic film recycling and treatment process according to claim 1, characterized in that: The screening machine (1) and the crusher (2) are respectively connected with a dust collector (13) through a first dust exhaust pipe (12) and a second dust exhaust pipe (14).

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