Battery pp diaphragm recycling and manufacturing equipment and preparation method

Abstract

The present application relates to the technical field of polymer material recycling, and particularly relates to a battery PP diaphragm recycling and reprocessing device and a preparation method, which comprises a shell, an extrusion screw rod is installed in the shell, and a power assembly is connected to the end of the extrusion screw rod; a feeding hopper is installed on the shell and is close to one side of the power assembly; an air inlet assembly is installed on the lower side of the shell and is communicated with the inside of the shell, and an air outlet hole is arranged on the upper side of the shell; a heating assembly is sleeved on the outside of the shell; a discharging assembly is installed on the end of the shell and is arranged opposite to the power assembly, and a filter screen assembly is installed in the discharging assembly; and a detection assembly is installed on the shell and is used for detecting the temperature and pressure of the material in the shell.

Description

Technical Field

[0001] This invention relates to the field of polymer material recycling technology, and in particular to a battery PP separator recycling and remanufacturing equipment and preparation method. Background Technology

[0002] As a core component of power batteries and energy storage batteries, battery separators play a crucial role in isolating the positive and negative electrodes to prevent internal short circuits. Simultaneously, their microporous structure must ensure the free movement of lithium ions during charge-discharge cycles, thereby achieving efficient storage and release of electrochemical energy. In recent years, with the continuous increase in the global penetration rate of new energy vehicles and the explosive growth in the installed capacity of electrochemical energy storage, the market demand for battery separators has shown a strong upward trend, and the industry scale has continued to expand.

[0003] In the production of battery separators, regardless of whether dry unidirectional or bidirectional stretching processes are used, or wet phase separation extraction technology is employed, a large amount of scrap material is generated during processes such as slitting, trimming, and finished product inspection. This scrap material has the same polyolefin chemical composition and highly oriented microporous structure as qualified separator products, and should possess extremely high reuse value. However, the current industry recycling system is still immature. In most cases, these scrap materials can only be downgraded for use in low-end injection-molded or blow-molded plastic products, or even directly disposed of as solid waste through incineration or landfill, resulting in a serious waste of high-quality polyolefin raw materials. Furthermore, existing recycling granulation equipment is mainly designed for general-purpose plastics and is ill-suited to the specific characteristics of battery separator materials, which are extremely sensitive to thermal history. If the temperature control is slightly off or the shear rate is too high during the melt extrusion process of diaphragm scraps, it is very easy to cause polymer chain breakage and degradation, destruction of oriented crystal structure and thermal decomposition of functional additives. This results in a wider molecular weight distribution of recycled particles, violent fluctuations in melt index and a significant decrease in pore-forming performance. Recycled materials with poor quality consistency cannot meet the stringent requirements of downstream diaphragm production for material cleanliness, batch stability and mechanical properties, thus restricting the recycling of diaphragm scraps.

[0004] Therefore, those skilled in the art are dedicated to developing a battery PP separator recycling and remanufacturing equipment and preparation method that facilitates the recycling of PP separators and ensures consistent quality of regenerated particles, thereby improving the recycling of PP membranes. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a battery PP separator recycling and remanufacturing equipment and preparation method, which facilitates the recycling of PP separators and ensures consistent quality of regenerated particles, thereby improving the recycling of PP membranes.

[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: a battery PP separator recycling and remanufacturing device, comprising... A housing, wherein a pressing screw is installed inside the housing, and a power assembly is connected to the end of the pressing screw; A feeding hopper is mounted on the housing and close to the power assembly. An air intake assembly is installed on the lower side of the housing and communicates with the interior of the housing; an exhaust port is provided on the upper side of the housing. A heating assembly, which is sleeved on the outside of the housing; A discharge assembly is installed at the end of the housing and is disposed opposite to the power assembly; a filter assembly is installed inside the discharge assembly. A detection component, which is mounted on the housing and used to detect the temperature and pressure of the material inside the housing; A control component, which is electrically connected to the power component, the intake component, the heating component, and the detection component.

[0007] The beneficial effects of adopting the above solution are: by coordinating the shell, extrusion screw, feeding hopper, air inlet assembly, exhaust port, heating assembly, discharge assembly, filter assembly, detection assembly and control assembly, the battery PP separator scraps can be recycled and remanufactured in an integrated manner from solid feeding to melt extrusion, filtration and exhaust. The combination of the air intake component and the exhaust port allows air to be introduced into the shell and moisture and volatile substances to be discharged during the melt extrusion process, effectively reducing the moisture in the melt and reducing bubbles and silver streaks in the recycled particles. At the same time, the closed-loop electrical connection between the detection component and the control component allows temperature and pressure to be monitored and adjusted in real time, avoiding polymer chain breakage and degradation caused by local overheating or overpressure. This ensures the stability of the molecular weight distribution and the consistency of the melt index of the recycled particles, improves the recycling rate of PP membrane scraps, and meets the material requirements of downstream membrane production.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the heating assembly includes a first heater and a second heater, both of which are mounted on the housing, and both the first heater and the second heater are gradient electric heaters.

[0010] The beneficial effects of adopting the above-mentioned further scheme are: both the first heater and the second heater adopt gradient electric heaters, so that the shell forms a precise temperature gradient from the low temperature zone to the high temperature zone along the axial direction. The granular raw material gradually heats up and melts during the transportation process, avoiding the problems of local temperature rise and excessive heating rate caused by single heating. This effectively inhibits the thermal degradation of PP polymer chains, the destruction of oriented crystal structure and the decomposition of functional additives, ensuring that the molecular weight distribution of recycled granules is narrow and the melt index fluctuation is small.

[0011] Furthermore, the discharge assembly includes a discharge seat, the discharge seat having a discharge chamber communicating with the inside of the housing, and a pellet discharge plate installed on the discharge chamber; The filter assembly includes a filter screen and a filter screen holder. At least one of the filter screens is mounted on the filter screen holder. The end of the filter screen holder is connected to a telescopic hydraulic cylinder. The discharge seat has a sliding groove for the filter screen holder to move. The sliding groove is located on the side of the discharge plate.

[0012] The beneficial effects of adopting the above-mentioned further solution are: the telescopic cylinder and the slide groove work together to realize the automatic push-pull replacement of the filter screen assembly. When the filter screen is clogged or needs to be replaced, the telescopic cylinder drives the filter screen holder to move out of the discharge chamber along the slide groove, so that one filter screen is used and another filter screen is reserved or replaced.

[0013] Furthermore, an ultrasonic generator is installed on the outer wall of the housing and on the side near the discharge assembly, and the ultrasonic generator is electrically connected to the control assembly.

[0014] The beneficial effects of adopting the above-mentioned further scheme are: the ultrasonic waves cause the molten fluid to be subjected to high-frequency ultrasonic vibration before discharge, and the ultrasonic cavitation effect generates a large number of microbubbles in the melt and drives them to oscillate, coalesce and break, thereby efficiently removing residual dissolved water, low molecular weight volatiles and monomers from the melt, significantly reducing the moisture content and VOC content of the recycled particles, and improving the cleanliness of the material. The mechanical shearing effect generated by ultrasonic vibration can destroy local high viscosity regions and tiny gel particles in the melt, promote melt homogenization, improve the deentanglement and redistribution of molecular chains, and further narrow the melt index fluctuation of the regenerated particles. Ultrasonic vibration can also inhibit the deposition of degradation products and impurities on the surface of the filter screen and the pellet discharge plate, delay filter screen clogging, extend the continuous operation cycle, and the ultrasonic generator is installed close to the discharge component, so that the devolatilization and homogenization are completed before the melt enters the filter screen, avoiding pressure fluctuations and streak defects caused by the retention of bubbles and volatiles by the filter screen, thereby comprehensively improving the quality consistency and appearance of the recycled pellets.

[0015] Furthermore, the detection component includes a first temperature sensor, a first pressure sensor, a second temperature sensor, and a second pressure sensor, with at least one first temperature sensor and at least one first pressure sensor installed in the middle of the housing; The second temperature sensor and the second pressure sensor are mounted on the housing and close to the discharge assembly. The second temperature sensor is a fluorescent fiber optic temperature sensor, and the second pressure sensor is a fiber optic pressure sensor.

[0016] The beneficial effects of adopting the above-mentioned further solution are: the detection component includes a first temperature sensor, a first pressure sensor, a second temperature sensor and a second pressure sensor, and the first temperature sensor and the first pressure sensor are arranged in the middle of the shell, and the second temperature sensor and the second pressure sensor are arranged near the discharge component, so as to realize segmented and accurate monitoring of temperature and pressure in the front, middle and rear stages of the melting process. The second temperature sensor is a fluorescent fiber optic temperature sensor, and the second pressure sensor is a fiber optic pressure sensor. The electromagnetic interference and mechanical vibration interference generated by the ultrasonic generator are completely isolated by the principle of pure optical signal transmission.

[0017] Furthermore, the output end of the discharge component is also provided with a cooling water tank, a cold air blower, a pelletizer and a floating batching device in sequence, and a metal separator is also installed on the floating batching device.

[0018] The beneficial effects of adopting the above-mentioned further scheme are: by sequentially setting a cooling water tank, a cold air blower, a pelletizer and a flotation batching device at the output end of the discharge component, and installing a metal separator on the flotation batching device, the entire process of molten strip material from cooling and shaping, air drying and dewatering to pelletizing, screening, flotation separation and metal removal is automated.

[0019] A method for preparing recycled PP separators for batteries, applied to the battery PP separator recycling equipment described above, includes the following steps: S100. Remove impurities from the PP film, clean it, and crush it to obtain granular raw material; S200. The granular raw material from step S100 is fed into the shell through the feeding hopper and conveyed by the extrusion screw; S300. During the conveying of granular raw materials, the first heater and the second heater are used to heat the shell so that the granular raw materials are conveyed from the low temperature zone to the high temperature zone and a molten fluid is formed at the end of the shell near the discharge component. The air inlet component is used to introduce air into the shell and discharge it from the exhaust port. S400. In step S300, the molten fluid enters the filter screen and the pelletizing plate in sequence to form a continuous strip. After passing through the cooling water tank and the cold air fan in sequence, it is then pelletized, floated, and metal objects are removed before being collected.

[0020] The beneficial effect of adopting the above-mentioned further scheme is that by organically integrating the steps of PP film impurity removal, cleaning and crushing, extrusion screw conveying, gradient heating and melting, gas inlet devolatilization, filtration and extrusion, cooling and pelletizing and flotation to remove metals into a continuous preparation method, the battery PP separator scraps are transformed from solid waste into high-quality recycled granules.

[0021] Furthermore, before step S400, the molten fluid is subjected to ultrasonic vibration.

[0022] The beneficial effects of adopting the above-mentioned further scheme are: ultrasonic oscillation causes the melt to undergo ultrasonic cavitation and mechanical shearing before filtration and extrusion, and the ultrasonic cavitation effect is used to deeply remove the residual trace moisture, extractant monomers and oligomers in the melt, avoiding the formation of bubbles or surface defects of these volatile substances during the subsequent cooling and pelletizing process. Ultrasonic homogenization improves the rheological properties of the melt, reduces the apparent viscosity, and decreases filter pressure drop and extrusion pressure fluctuations, resulting in more stable and uniform strip extrusion.

[0023] Furthermore, the oscillation power of the ultrasound is ; in, This represents the density of the PP film in its molten state. The propagation speed of ultrasound in molten PP film; A represents the effective area of ​​the ultrasound wave. The frequency of the ultrasonic wave; The amplitude of the ultrasonic wave; This refers to the sound-to-electricity conversion efficiency.

[0024] The beneficial effects of adopting the above-mentioned further solution are: the control component accurately calculates and regulates the ultrasonic output according to the actual working parameters, thereby improving the forming efficiency and quality of PP film.

[0025] Furthermore, in step S300, the pressure and temperature of the molten fluid satisfy the following conditions: The heating temperature of the first heater is T1, the heating temperature of the second heater is T2, and the pressure of the molten fluid near the discharge assembly is P; The following relationship exists between T1, T2, and P: T2 = T0 + k(P0 - P) in: T0 is the reference temperature, with a value ranging from 200℃ to 220℃; P0 is the reference pressure, with a value ranging from 8MPa to 12MPa; k is the pressure compensation coefficient, with a value ranging from 1.5℃ / MPa to 3.0℃ / MPa; P represents the actual test pressure, with a value ranging from 5 MPa to 15 MPa; Furthermore, the value of T1 ranges from 170℃ to 200℃; The value of T2 ranges from 200℃ to 230℃; And satisfy T2≥T1+15℃; When P > 10 MPa, T2 takes the lower limit of the interval; When P≤10MPa, T2 takes the upper limit of the interval.

[0026] The beneficial effects of adopting the above-mentioned further solution are: when the melt pressure increases, the additional temperature rise generated by the extrusion work will cause the actual temperature of the material to exceed the set value of the heater. According to the setting, the heating temperature of the second heater is actively reduced, which effectively avoids the PP molecular chain from breaking and degrading due to overheating, and ensures that the molecular weight and distribution of the recycled particles are highly consistent with the raw materials. When the melt pressure is too low, the heating temperature is actively increased according to the set data to compensate for insufficient fluidity, ensuring that the melt still has a suitable flow rate under changing working conditions, so that the extruded strips are continuous and uniform. By limiting the T2 and T1 temperature settings, the shell maintains a positive temperature gradient along the material conveying direction, making the phase transformation process of the particulate raw material from solid to molten fluid smooth and controllable, avoiding the destruction of the orientation crystal structure and the thermal decomposition of functional additives caused by sudden heating. The synergistic effect of dynamic temperature compensation mechanism and gradient temperature difference design transforms manual control that relies on operator experience into quantitative closed-loop control based on real-time detection data. This ensures that the thermal history of the molten fluid is basically consistent for each batch, resulting in a narrower range of melt index fluctuations, stable pore-forming performance, and significantly improved quality consistency for the regenerated particles. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a battery PP separator recycling and remanufacturing equipment according to a specific embodiment of the present invention; Figure 2 This is a schematic diagram of a production line for recycling and remanufacturing battery PP separators according to a specific embodiment of the present invention.

[0028] The attached diagram lists the components represented by each number as follows: 1. Shell; 2. Power assembly; 3. Feed hopper; 4. Air inlet assembly; 5. Exhaust port; 6. Heating assembly; 7. Discharge assembly; 8. Filter assembly; 9. Detection assembly; 10. Control assembly; 11. First heater; 12. Second heater; 13. Discharge seat; 14. Discharge chamber; 15. Pelletizing plate; 16. Filter holder; 17. Filter; 18. Telescopic cylinder; 19. Ultrasonic generator; 20. First temperature sensor; 21. First pressure sensor; 22. Second temperature sensor; 23. Second pressure sensor; 24. Cooling water tank; 25. Air cooler; 26. Pelletizer; 27. Floating batching device; 28. Metal separator. Detailed Implementation

[0029] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0030] In the description of this invention, it should be understood that the terms "center," "length," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "inner," "outer," "circumferential," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the system or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0032] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] like Figure 1 and Figure 2 As shown, a battery PP separator recycling and remanufacturing equipment includes a housing 1, which can be integrally cast from metal alloy steel. An extrusion screw is installed inside the housing 1. The end of the extrusion screw is connected to the output shaft of the gearbox through a spline coupling. The input end of the gearbox is connected to a power assembly 2, which includes a variable frequency speed-regulating three-phase asynchronous motor. Feeding hopper 3 is installed on the housing 1 and close to the power component 2. The feeding hopper 3 is a conical hopper and has a dust removal exhaust port at the top that is connected to the negative pressure dust removal system. Air intake assembly 4 is installed on the lower side of housing 1 and communicates with the inside of housing 1. Air intake assembly 4 uses multiple independent fans. Air is delivered tangentially from the bottom of housing 1 into the screw groove. The fan motor is a variable frequency motor, which can automatically adjust the speed according to the moisture content of the material to adjust the air intake. An exhaust port 5 is provided on the upper side of housing 1. The exhaust port 5 is equipped with a stainless steel wire mesh baffle to prevent molten material from escaping with the airflow. An air collection hood and an exhaust fan are connected above the exhaust port 5. Heating component 6 is sleeved on the outside of housing 1; The discharge assembly 7 is installed at the end of the housing 1 and is positioned opposite to the power assembly 2. The discharge assembly 7 contains a filter assembly 8. The detection component 9 is installed on the housing 1 and is used to detect the temperature and pressure of the material inside the housing 1. The probe of the detection component 9 is inserted into the inner wall of the housing 1 through a radial threaded hole. The probe end face is flush with the inner wall of the barrel to avoid material accumulation. The signal cable is laid along the wire groove on the outer wall of the barrel and passes through the metal flexible hose for protection or heating component 6. The control component 10 is a PLC programmable logic controller or an industrial control computer, equipped with an analog input / output module, a temperature control module, a communication module and a human-machine interface touch screen. The control component 10 is electrically connected to the power component 2, the air intake component 4, the heating component 6 and the detection component 9. It realizes closed-loop control of temperature, pressure and speed through PID algorithm, and has over-temperature and over-pressure alarm and automatic protection shutdown functions.

[0034] like Figure 1 As shown, in some embodiments, the heating component 6 includes a first heater 11 and a second heater 12. Both the first heater 11 and the second heater 12 are mounted on the housing 1, and both the first heater 11 and the second heater 12 are gradient electric heaters. The first heater 11 is arranged in the front section of the housing 1, i.e., the compression section area, and the second heater 12 is arranged in the rear section of the housing 1, i.e., the homogenization and metering section area. The first heater 11 and the second heater 12 are each independently equipped with a solid-state relay or a thyristor power regulator, which receives PWM pulse signals from the control component 10 for power adjustment. The set temperature of the first heater 11 is lower than the set temperature of the second heater 12, forming a temperature gradient from low to high along the material conveying direction. The actual temperature of each section is fed back to the control component 10 by thermocouples embedded between the heating coil and the barrel wall to achieve precise temperature control. By utilizing the thermal history sensitivity of the PP film, the material is preheated and initially dehydrated in the low-temperature zone, and fully plasticized and homogenized in the high-temperature zone, avoiding molecular chain breakage and degradation caused by overall high temperature.

[0035] In another embodiment, the discharge assembly 7 includes a discharge seat 13, which is made of high-strength alloy steel forging and has a discharge cavity 14 inside. The discharge cavity 14 is a cylindrical or conical flow channel with a flow channel diameter that gradually narrows along the discharge direction to establish extrusion pressure. The discharge cavity 14 is connected to the inside of the housing 1. A pellet plate 15 is installed at the end of the discharge cavity 14. The pellet plate 15 has multiple discharge holes and is installed on the end face of the discharge seat 13.

[0036] The filter assembly 8 includes a filter screen 17 and a filter screen holder 16. The filter screen 17 is a multi-layer stainless steel wire mesh stacked structure. At least one filter screen 17 is installed on the filter screen holder 16. The filter screen holder 16 is a rectangular frame structure with high-temperature resistant sealing strips around the frame. The end of the filter screen holder 16 is connected to the piston rod of the telescopic cylinder 18 through a pin or hinge. The telescopic cylinder 18 is a double-acting hydraulic cylinder, supplied with oil by a hydraulic station and controlled by an electromagnetic reversing valve to extend and retract. The discharge seat 13 has a sliding groove for the movement of the filter screen holder 16. The sliding groove is located on the side of the discharge plate 15 and is perpendicularly connected to the discharge chamber 14. When the filter screen 17 is blocked, causing the melt pressure to exceed the set threshold, the control assembly 10 sends a signal to drive the telescopic cylinder 18 to pull the filter screen holder 16 in use out of the discharge chamber 14 along the sliding groove. At the same time, another filter screen holder 16 with a spare filter screen 17 pre-installed is pushed into the working position, realizing automatic screen replacement without stopping the machine. After the blocked filter screen 17 is removed, it can be cleaned or replaced offline.

[0037] In this embodiment, an ultrasonic generator 19 is installed on the outer wall of the housing 1 and on the side near the discharge assembly 7. The ultrasonic generator 19 is electrically connected to the control assembly 10. The control assembly 10 adjusts the start / stop, power and frequency of the ultrasonic waves according to the material state and process requirements.

[0038] The detection component 9 includes a first temperature sensor 20, a first pressure sensor 21, a second temperature sensor 22, and a second pressure sensor 23. At least one first temperature sensor 20 and at least one first pressure sensor 21 are installed in the middle of the housing 1, in the transition area between the first heater 11 and the second heater 12, to monitor the temperature and pressure state of the material as it enters the homogenization section from the compression section. The first temperature sensor 20 can be an armored K-type thermocouple with its measuring end close to the inner wall of the barrel. The first pressure sensor 21 can be a strain gauge melt pressure sensor, transmitting pressure to the downstream sensing chip via high-temperature silicone oil. The second temperature sensor 22 and the second pressure sensor 23 are installed on the housing 1 and close to the discharge component 7 to monitor the final temperature and pressure of the melt before it enters the discharge chamber 14. The second temperature sensor 22 is a fluorescent fiber optic temperature sensor, unaffected by ultrasonic electromagnetic interference and the strong electric field of the barrel. The second pressure sensor 23 is a fiber optic pressure sensor, possessing electromagnetic compatibility and vibration resistance. The fiber optic cables of the second temperature sensor 22 and the second pressure sensor 23 are laid along the outer wall of the barrel and connected to the fiber optic demodulation module of the control component 10 to achieve highly reliable monitoring of the molten fluid state.

[0039] In other embodiments, the output end of the discharge component 7 is also sequentially provided with a cooling water tank 24, a cool air fan 25, a pelletizer 26, and a flotation batching device 27. The flotation batching device 27 is also equipped with a metal separator 28. Specifically, the cooling water tank 24 is a long stainless steel tank for rapid cooling of the PP film. The cool air fan 25 is an axial flow fan or a centrifugal fan with a flow equalization plate at the air outlet to dry the residual moisture on the surface of the strip. The pelletizer 26 cuts the strip into cylindrical or square particles. The flotation batching device 27 can be a straight-cylinder flotation device with a circulating water pump and nozzles inside the cylinder to form an upward water flow. Utilizing the density difference between PP particles and impurity particles, the PP particles are suspended or slowly settle while the impurities are carried away by the water flow, achieving separation and purification. The flotation batching device 27 is also equipped with a metal separator 28, which is an electromagnetic iron remover or an eddy current separator, used to remove metal debris mixed in during the recycling process to ensure the cleanliness of the recycled particles.

[0040] A method for preparing recycled PP separators for batteries, applied to the battery PP separator recycling equipment described above, includes the following steps: S100. Remove impurities from the PP film, clean it, and crush it to obtain granular raw material; S200. The granular raw material in step S100 is fed into the shell 1 through the feeding hopper 3 and conveyed by the extrusion screw. The extrusion screw rotates at a set speed under the drive of the power component 2, pushing the material from the feeding end to the discharging end. S300. During the conveying of granular raw materials, the first heater 11 and the second heater 12 are used to heat the shell 1 so that the granular raw materials are conveyed from the low temperature zone to the high temperature zone and form a molten fluid at the end of the shell near the discharge component 7. The temperature of the section where the first heater 11 is located is set to 160°C to 200°C. The material is preheated, compacted and initially melted in this section. At the same time, the moisture begins to evaporate. The air inlet component 4 introduces clean air into the shell 1. The airflow enters the screw channel from the bottom and fully contacts the material. It carries water vapor and volatile organic compounds and is discharged from the top exhaust port 5. The temperature of the section where the second heater 12 is located is set to 220°C to 260°C. The material is completely melted in this section and the molecular chains are fully de-entangled and homogenized. The uniformity of the melt temperature is controlled within ±3°C.

[0041] This also includes ultrasonic vibration of the molten fluid; The oscillation power of the ultrasound is ; in, This represents the density of the PP film in its molten state. The propagation speed of ultrasound in molten PP film; A represents the effective area of ​​the ultrasound wave. The frequency of the ultrasonic wave; The amplitude of the ultrasonic wave; This refers to the sound-to-electricity conversion efficiency.

[0042] The control component 10 calculates the theoretical ultrasonic power according to the above formula, and combines the feedback values ​​of the second temperature sensor 22 and the second pressure sensor 23 to adjust the output power of the ultrasonic generator 19 in real time, so that the melt can achieve devolatilization and homogenization under the low temperature and low pressure coordinated control conditions, and avoid the melt temperature rise and degradation caused by excessive ultrasonic energy input.

[0043] When ultrasound propagates in the melt, it generates alternating compressed and rarefied phases. The local pressure in the rarefied phase is lower than the saturated vapor pressure of the melt, causing dissolved water and volatile substances to vaporize and form microbubbles, i.e., the ultrasonic cavitation effect. The microbubbles collapse rapidly in the compressed phase, generating local high temperature and pressure and strong microjets, which promotes the diffusion of gas inside the bubbles into the bulk gas phase, thereby deeply removing trace amounts of water, residual extractant monomers, and oligomers from the melt. At the same time, the mechanical vibration of ultrasound causes strong shearing and turbulence in the melt, destroying local high viscosity areas and tiny gel particles, promoting the deentanglement and redistribution of molecular chains, reducing the apparent viscosity of the melt, reducing the pressure drop of filter screen 17 and the fluctuation of extrusion pressure. In addition, the acoustic flow effect of ultrasound can wash the surface of filter screen 17 and granulation plate 15, inhibiting the deposition of degradation products and impurities, delaying filter clogging, and extending the continuous operation cycle.

[0044] The pressure and temperature of the molten fluid meet the following conditions: the heating temperature of the first heater 11 is T1, the heating temperature of the second heater 12 is T2, and the pressure of the molten fluid near the discharge assembly 7 is P. The following relationship exists between T1, T2, and P: T2 = T0 + k(P0 - P) in: T0 is the reference temperature, with a value ranging from 200℃ to 220℃; P0 is the reference pressure, with a value ranging from 8MPa to 12MPa; k is the pressure compensation coefficient, with a value ranging from 1.5℃ / MPa to 3.0℃ / MPa; P represents the actual test pressure, with a value ranging from 5 MPa to 15 MPa; Furthermore, the value of T1 ranges from 170℃ to 200℃; The value of T2 ranges from 200℃ to 230℃; And satisfy T2≥T1+15℃; When P > 10 MPa, T2 takes the lower limit of the interval; When P≤10MPa, T2 takes the upper limit of the interval.

[0045] S400. In step S300, the molten fluid sequentially enters the filter screen 17 and the pelletizing plate 15 to form a continuous strip. The filter screen 17 filters out unmelted particles, gel blocks, and impurities. The pelletizing plate 15 divides the melt into multiple round strips with a diameter of 2mm to 4mm. After exiting the pelletizing plate 15, the strips enter the cooling water tank 24 and are rapidly cooled in the water until the surface hardens. Then, the surface moisture is blown off by the cold air blower 25, and then the strips enter the pelletizer 26 to be cut into particles. The particles enter the flotation batching device 27 for flotation separation to remove impurities with a density greater than PP. Finally, after passing through the metal separator 28 to remove metal foreign objects, the particles are collected and packaged.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A battery PP separator recycling and remanufacturing equipment, characterized in that: include Housing (1), a pressing screw is installed inside the housing (1), and a power assembly (2) is connected to the end of the pressing screw. Feeding hopper (3), the feeding hopper (3) is installed on the housing (1) and close to the power assembly (2); An air intake assembly (4) is installed on the lower side of the housing (1) and communicates with the interior of the housing (1). An exhaust port (5) is provided on the upper side of the housing (1). Heating component (6), which is sleeved on the outside of the housing (1); The discharge assembly (7) is installed at the end of the housing (1) and is disposed opposite to the power assembly (2). The discharge assembly (7) is equipped with a filter assembly (8). A detection component (9) is installed on the housing (1) and used to detect the temperature and pressure of the material inside the housing (1); The control component (10) is electrically connected to the power component (2), the air intake component (4), the heating component (6) and the detection component (9).

2. The battery PP separator recycling and remanufacturing equipment according to claim 1, characterized in that: The heating assembly (6) includes a first heater (11) and a second heater (12), both of which are mounted on the housing (1), and both the first heater (11) and the second heater (12) are gradient electric heaters.

3. The battery PP separator recycling and remanufacturing equipment according to claim 1, characterized in that: The discharge assembly (7) includes a discharge seat (13), the discharge seat (13) has a discharge chamber (14), the discharge chamber (14) communicates with the inside of the housing (1), and a pellet discharge plate (15) is installed on the discharge chamber (14). The filter assembly (8) includes a filter (17) and a filter holder (16). At least one of the filter (17) is mounted on the filter holder (16). The end of the filter holder (16) is connected to a telescopic cylinder (18). The discharge seat (13) has a sliding groove for the filter holder (16) to move. The sliding groove is located on the side of the discharge plate (15).

4. The battery PP separator recycling and remanufacturing equipment according to claim 1, characterized in that: An ultrasonic generator (19) is installed on the outer wall of the housing (1) and on the side near the discharge assembly (7). The ultrasonic generator (19) is electrically connected to the control assembly (10).

5. The battery PP separator recycling and remanufacturing equipment according to claim 1, characterized in that: The detection component (9) includes a first temperature sensor (20), a first pressure sensor (21), a second temperature sensor (22), and a second pressure sensor (23), with at least one first temperature sensor (20) and at least one first pressure sensor (21) installed in the middle of the housing (1); The second temperature sensor (22) and the second pressure sensor (23) are mounted on the housing (1) and close to the discharge assembly (7). The second temperature sensor (22) is a fluorescent fiber optic temperature sensor and the second pressure sensor (23) is a fiber optic pressure sensor.

6. The battery PP separator recycling and remanufacturing equipment according to claim 1, characterized in that: The output end of the discharge component (7) is also provided with a cooling water tank (24), a cold air blower (25), a pelletizer (26) and a floating batching device (27), and a metal separator (28) is also installed on the floating batching device (27).

7. A method for preparing recycled PP separators for batteries, applied to the battery PP separator recycling equipment as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S100. Remove impurities from the PP film, clean it, and crush it to obtain granular raw material; S200. The granular raw material in step S100 is fed into the shell (1) through the feeding hopper (3) and conveyed by the extrusion screw; S300. During the conveying of granular raw materials, the first heater (11) and the second heater (12) are used to heat the shell (1) so that the granular raw materials are conveyed from the low temperature zone to the high temperature zone and a molten fluid is formed at the end of the shell near the discharge assembly (7). The air inlet assembly (4) is used to introduce air into the shell (1) and discharge it from the exhaust port (5). S400. In step S300, the molten fluid enters the filter screen (17) and the pelletizing plate (15) in sequence to form a continuous strip. After passing through the cooling water tank (24) and the cold air blower (25) in sequence, it is then granulated, floated, and metal objects are removed before being collected.

8. The method for preparing battery PP separators by recycling and remanufacturing according to claim 7, characterized in that: The process before step S400 also includes ultrasonic vibration of the molten fluid.

9. The method for preparing battery PP separators by recycling and remanufacturing according to claim 8, characterized in that: The oscillation power of the ultrasound is ; in, This represents the density of the PP film in its molten state. The propagation speed of ultrasound in molten PP film; A represents the effective area of ​​the ultrasound wave. The frequency of the ultrasonic wave; The amplitude of the ultrasonic wave; This refers to the sound-to-electricity conversion efficiency.

10. The method for preparing battery PP separator by recycling and remanufacturing according to claim 7, characterized in that, In step S300, the pressure and temperature of the molten fluid satisfy the following conditions: The heating temperature of the first heater (11) is T1, the heating temperature of the second heater (12) is T2, and the pressure of the molten fluid near the discharge assembly (7) is P; The following relationship exists between T1, T2, and P: T2 = T0 + k(P0 - P) in: T0 is the reference temperature, with a value ranging from 200℃ to 220℃; P0 is the reference pressure, with a value ranging from 8MPa to 12MPa; k is the pressure compensation coefficient, with a value ranging from 1.5℃ / MPa to 3.0℃ / MPa; P represents the actual test pressure, with a value ranging from 5 MPa to 15 MPa; Furthermore, the value of T1 ranges from 170℃ to 200℃; The value of T2 ranges from 200℃ to 230℃; And satisfy T2≥T1+15℃; When P > 10 MPa, T2 takes the lower limit of the interval; When P≤10MPa, T2 takes the upper limit of the interval.

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