Permanent antistatic pc material preparation system

Abstract

This invention provides a permanent antistatic PC material preparation system, comprising a mixing unit, an extrusion granulation unit, and an injection molding unit connected in sequence. The injection molding unit includes a barrel, a screw assembly rotatably disposed within the barrel, and an ERT sensor disposed at a nozzle at the end of the barrel. The ERT sensor includes an electrode array for online acquisition of electrical impedance tomography (EIT) data of the melt passing through the nozzle. The screw assembly includes a screw spindle with a longitudinally penetrating internal heat conduction oil channel. This internal heat conduction oil channel is connected to an external temperature control system via a connector. One section of the barrel is a compression section. A segmented thermal response sleeve is fitted around the outer periphery of the screw spindle within the compression section. The outer surface of the thermal response sleeve is provided with an outer peripheral conveying spiral. The thermal response sleeve responds to changes in the fluid temperature within the internal heat conduction oil channel by generating radial expansion displacement, thereby dynamically adjusting the compression ratio by changing the effective root diameter of the screw assembly within the compression section.

Description

Technical Field

[0001] This invention relates to the field of injection molding structure technology, and in particular to a system for preparing permanent antistatic PC materials. Background Technology

[0002] Permanent antistatic polycarbonate (PC) materials are typically produced by melt blending, where carbon nanotubes, conductive carbon black, or other polymeric antistatic components are uniformly dispersed within a PC matrix to form a conductive network. The resulting product is then manufactured through processes such as extrusion granulation, injection molding, or compression molding. Therefore, a permanent antistatic PC material manufacturing system includes a mixing unit, an extrusion granulation unit, and a subsequent injection molding unit. The extrusion granulation process thoroughly mixes, disperses, and granulates the PC matrix with the antistatic components, while the injection molding unit melts, injects, or compresses the granules to ultimately form the desired product. The key to this entire system is maintaining the integrity of the conductive pathways and the uniform distribution of the antistatic components within the product, thereby ensuring the material possesses stable and durable antistatic properties.

[0003] However, conventional injection molding units, i.e., injection molding machines, generally use a three-stage screw with a fixed compression ratio. During the compression stage, the particulate product undergoes intense shearing and compression. This process causes severe flow deformation of the melt. Due to the limited interfacial bonding strength between carbon nanotubes and the PC matrix, the carbon nanotubes may bend, break, or even detach from the matrix, thereby disrupting the conductive pathways formed by the contact between the carbon nanotubes and significantly reducing antistatic properties. Furthermore, as shearing and compression intensify, the melt temperature rises, and fluctuations in processing temperature can cause uneven distribution of antistatic components such as carbon nanotubes and graphene on the product surface, further affecting antistatic performance. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems by providing a permanent antistatic PC material preparation system.

[0005] The technical solution of the present invention is a permanent antistatic PC material preparation system, comprising a mixing unit, an extrusion granulation unit, and an injection molding unit connected in sequence. The injection molding unit includes a barrel, a screw assembly rotatably disposed inside the barrel, and an ERT sensor disposed at the nozzle at the end of the barrel. The ERT sensor includes an electrode array for online acquisition of electrical impedance tomography data of the melt passing through the nozzle. The screw assembly includes a screw spindle with a longitudinally penetrating inner core heat conduction oil channel. This inner core heat conduction oil channel is connected to an external temperature control system via a connector. One section of the barrel is a compression section. A segmented thermal response sleeve is fitted around the outer circumference of the screw spindle within the compression section. An outer circumferential conveying spiral is provided on the outer surface of the thermal response sleeve. The pitch and helix angle of the outer circumferential conveying spiral are consistent with those of the screw spindle to form a continuous melt conveying path. The thermal response sleeve is circumferentially fixed to the screw spindle via an axial positioning key and axially limited by a fixing ring. Sealing rings are provided at both ends of the mating surface between the thermal response sleeve and the screw spindle. The thermal response sleeve responds to changes in the fluid temperature within the inner core heat conduction oil channel by generating radial expansion displacement, thereby dynamically adjusting the compression ratio by changing the effective root diameter of the screw assembly within the compression section. The injection molding unit also includes an ultrasonic auxiliary device, which is located on the melt flow channel after the nozzle at the end of the barrel and before the mold cavity, and is used to apply high-frequency vibration to the melt before it enters the mold cavity. It also includes a controller, which is electrically connected to the ERT sensor, the temperature control system, the ultrasonic auxiliary device, and the drive motor of the screw assembly. The controller controls the temperature control system in real time to adjust the oil temperature to dynamically adjust the compression ratio based on the electrical impedance tomography data fed back by the ERT sensor, and synchronously adjusts the output power of the ultrasonic auxiliary device and the drive motor.

[0006] In one embodiment, the joint is a multi-channel rotary joint, which includes a fixed stationary outer shell and a rotating inner core that rotates synchronously with the screw spindle. The heat conduction oil passage of the inner core includes an oil inlet pipe disposed at the center of the screw spindle and a concentric oil return pipe fitted around the outer periphery of the oil inlet pipe. The oil inlet pipe and the oil return pipe are respectively connected to the oil inlet and oil return port on the stationary outer shell through the rotating inner core, so as to maintain the continuous circulation of the heat conduction fluid when the screw spindle is rotating.

[0007] In one embodiment, the sealing ring is a radially adaptive combined seal.

[0008] In one embodiment, the thermally responsive sliding sleeve is made of an alloy material with a high coefficient of thermal expansion, and the thermally responsive sliding sleeve has several axial slits evenly distributed along the circumference, with each segment of the thermally responsive sliding sleeve being reset by an elastic connector.

[0009] In one embodiment, the ERT sensor further includes an embedded insulating bushing, with the electrode array arranged circumferentially at equal intervals on the inner wall of the bushing.

[0010] In one embodiment, the ultrasonic-assisted device includes a transducer arranged in a ring around the outer periphery of the melt channel and an amplitude transformer communicating with the inner cavity of the melt channel, with the end of the amplitude transformer extending to the central region of the melt channel.

[0011] As one implementation, when the impedance fluctuation fed back by the ERT sensor exceeds a preset threshold, the controller first adjusts the speed of the drive motor to perform instantaneous shear force compensation, and then adjusts the oil temperature through the temperature control system to correct the screw compression ratio.

[0012] In one embodiment, the inner wall of the compression section of the barrel is provided with a friction-reducing coating to reduce the frictional resistance between the thermally responsive sliding sleeve and the inner wall of the barrel during radial displacement.

[0013] In one embodiment, the threaded surface of the outer peripheral conveying spiral is hardened, and its hardness is higher than that of the surface hardness of the screw spindle.

[0014] In one implementation, the feeding drive device of the mixing unit is electrically connected to the controller, and the amount of antistatic additive added is adjusted in real time according to the melt composition uniformity monitored by the ERT sensor.

[0015] The advantages of this invention compared to existing technologies are that this permanent antistatic PC material preparation system achieves real-time monitoring and adaptive protection of the conductive pathways within the melt. By integrating an ERT sensor at the nozzle end, it solves the problem that conventional injection molding units cannot monitor antistatic performance fluctuations online, providing support for closed-loop regulation. Addressing the defect of conventional injection molding units where strong shearing due to a fixed compression ratio easily damages the connectivity of carbon nanotubes, this system dynamically changes the effective root diameter of the compression section through radial expansion displacement generated by a thermally responsive sliding sleeve, achieving mechanical deformation compensation driven by ERT sensor monitoring data and actively reducing shear strength. Furthermore, the high-frequency vibration applied to the melt by an ultrasonic auxiliary device induces the rearrangement of segregated antistatic components, effectively restoring the conductive pathways. In addition, cross-unit feedforward compensation control ensures mixing uniformity. Through the combined effects of monitoring, deformation compensation, and acoustic field restoration, this system ensures that the final PC molded product possesses stable, uniform, and durable antistatic properties. Attached Figure Description

[0016] Figure 1 A block diagram of a permanent antistatic PC material preparation system provided for an embodiment of the present invention; Figure 2 A first perspective view of the injection molding unit of the permanent antistatic PC material preparation system provided in an embodiment of the present invention; Figure 3A second perspective view of the injection molding unit of the permanent antistatic PC material preparation system provided in an embodiment of the present invention; Figure 4 A partial cross-sectional view of a screw assembly provided for an embodiment of the present invention; Figure 5 A cross-sectional view of a screw assembly provided for an embodiment of the present invention; Figure 6 A control connection block diagram of a permanent antistatic PC material preparation system provided for an embodiment of the present invention.

[0017] In the diagram: 1. Mixing unit; 2. Extrusion granulation unit; 3. Injection molding unit; 4. Barrel; 5. Screw assembly; 6. ERT sensor; 7. Electrode array; 8. Screw spindle; 9. Inner core heat conduction oil channel; 10. Connector; 11. Temperature control system; 12. Compression section; 13. Thermal response sleeve; 14. Outer peripheral conveying screw; 15. Axial positioning key; 16. Fixing ring; 17. Sealing ring; 18. Ultrasonic auxiliary device; 19. Melt channel; 20. Controller; 21. Drive motor; 22. Oil inlet pipe; 23. Oil return pipe; 24. Oil inlet; 25. Oil return port; 26. Axial slit; 27. Feeding drive device. Detailed Implementation

[0018] The above and other embodiments and advantages of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] In one implementation, such as Figures 1 to 6 As shown.

[0020] The permanent antistatic PC material preparation system provided in this embodiment includes a mixing unit 1, an extrusion granulation unit 2, and an injection molding unit 3 connected in sequence. The injection molding unit 3 includes a barrel 4, a screw assembly 5 rotatably disposed within the barrel 4, and an ERT sensor 6 disposed at the nozzle at the end of the barrel 4. The ERT sensor 6 includes an electrode array 7 for online acquisition of electrical impedance tomography data of the melt passing through the nozzle. The screw assembly 5 includes a screw spindle 8, and the screw spindle 8 is internally equipped with... A longitudinally penetrating inner core heat conduction oil channel 9 is connected to an external temperature control system 11 via a connector 10. One section of the barrel 4 is a compression section 12. A segmented thermal response sleeve 13 is fitted around the outer periphery of the screw spindle 8 located in the compression section 12. An outer peripheral conveying spiral 14 is provided on the outer surface of the thermal response sleeve 13. The pitch and helix angle of the outer peripheral conveying spiral 14 are consistent with those of the screw spindle 8 to form a continuous melt conveying path. The thermal response sleeve 13 is connected to the screw spindle via an axial positioning key 15. The screw assembly 5 is circumferentially fixed and axially limited by a retaining ring 16. Sealing rings 17 are provided at both ends of the mating surface between the thermally responsive sliding sleeve 13 and the screw spindle 8. The thermally responsive sliding sleeve 13 generates radial expansion displacement in response to changes in the fluid temperature within the inner core heat conduction oil channel 9, thereby dynamically adjusting the compression ratio by changing the effective root diameter of the screw assembly 5 within the compression section 12. The injection molding unit 3 includes an ultrasonic auxiliary device 18, which is located on the melt flow channel 19 after the nozzle at the end of the barrel 4 and before the mold cavity, for applying high-frequency vibration to the melt before it enters the mold cavity. It also includes a controller 20, which is electrically connected to the ERT sensor 6, the temperature control system 11, the ultrasonic auxiliary device 18, and the drive motor 21 of the screw assembly 5. The controller 20 controls the temperature control system 11 in real time to adjust the oil temperature to dynamically adjust the compression ratio based on the electrical impedance tomography data fed back by the ERT sensor 6, and simultaneously adjusts the output power of the ultrasonic auxiliary device 18 and the drive motor 21.

[0021] In this embodiment, the ERT sensor 6, or electrical impedance tomography sensor, utilizes a spatially distributed electrode array 7 to apply high-frequency electrical excitation to the field and reconstructs the conductivity distribution of the internal medium by measuring the boundary voltage response. Therefore, just before the melt leaves the barrel 4, the electrode array 7 of the ERT sensor 6 collects the electrical impedance tomography data of the melt. This data directly reflects the connectivity and dispersion uniformity of the conductive pathways formed by antistatic components such as carbon nanotubes inside the PC melt.

[0022] In this embodiment, unlike traditional screw structures, the screw assembly 5 has a longitudinally penetrating inner core heat conduction oil channel 9 inside the screw spindle 8. This inner core heat conduction oil channel 9 consists of an oil inlet pipe 22 and an oil return pipe 23. The inner core heat conduction oil channel 9 is connected to a temperature control system 11 via a connector 10, which can change the fluid temperature within the inner core heat conduction oil channel 9. One section of the barrel 4 is a compression section 12. Correspondingly, a segmented thermal response sleeve 13 is fitted around the outer periphery of the screw spindle 8 in the compression section 12. The segmented thermal response sleeve 13 here refers to a tubular sleeve structure composed of multiple arc-shaped metal segments segmented along the circumferential direction. Its material is sensitive to temperature changes and can deform radially when heated. The thermal response sleeve 13 is circumferentially fixed to the screw spindle 8 via an axial positioning key 15, allowing the thermal response sleeve 13 to rotate synchronously with the screw spindle 8 without relative slippage. The two ends of the thermally responsive sleeve 13 are axially limited by a retaining ring 16 integrally connected to the screw spindle 8 and axially positioned by a locating key 15. Furthermore, sealing rings 17 are provided at both ends of the mating surface between the thermally responsive sleeve 13 and the screw spindle 8 to prevent high-pressure melt from entering the mating gap between the thermally responsive sleeve 13 and the screw spindle 8. During operation, the thermally responsive sleeve 13 undergoes radial expansion displacement in response to changes in the fluid temperature within the inner core heat conduction oil passage 9. That is, after being heated, each lobe of the sleeve expands outward along a direction perpendicular to the axis of the screw spindle 8. This minute radial movement changes the effective root diameter of the screw assembly 5 within the compression section 12, thus changing the compression ratio of the injection molding unit 3.

[0023] In this embodiment, the ultrasonic auxiliary device 18 is disposed on the melt flow channel 19 after the nozzle at the end of the barrel 4 and before the mold cavity, and uses high-frequency vibration to induce the antistatic components such as carbon nanotubes to rearrange in order to restore the conductive path.

[0024] Therefore, compared to the fixed compression ratio of the conventional injection molding unit 3, the fixed strong shear force easily severs the conductive path when processing permanent antistatic PC materials. The permanent antistatic PC material preparation system provided in this embodiment realizes online monitoring of the melt at the nozzle end through the ERT sensor 6. When the ERT sensor 6 detects an increase in melt impedance, it means that the conductive path is damaged. The controller 20 instructs the temperature control system 11 to reduce the oil temperature entering the inner core heat conduction oil channel 9. The thermal response sleeve 13 then contracts upon cooling, and the radial expansion displacement decreases, resulting in a smaller effective root diameter of the compression section 12 and a relatively deeper thread groove. The increase in groove depth directly leads to a decrease in the compression ratio of the melt in this area, and the shear force is weakened accordingly, thereby actively avoiding and protecting the antistatic components such as carbon nanotubes from the hardware level. At the same time, the controller 20 also instructs the ultrasonic auxiliary device 18 to use the acoustic flow effect generated by high-frequency ultrasonic vibration in the melt flow channel 19 to induce the antistatic components that have segregated due to the previous slight shearing to rearrange and restore the conductive path. This closed-loop control, which directly drives mechanical structure deformation and acoustic field intervention using electrical impedance tomography data, enables adaptive processing and ensures stable and durable antistatic properties of the final molded product.

[0025] In one embodiment, the permanent antistatic PC material preparation system has a multi-channel rotary joint 10, which includes a fixed stationary outer shell and a rotating inner core that rotates synchronously with the screw spindle 8. The heat conduction oil passage 9 of the inner core includes an oil inlet pipe 22 disposed at the center of the screw spindle 8 and a concentric oil return pipe 23 fitted around the outer periphery of the oil inlet pipe 22. The oil inlet pipe 22 and the oil return pipe 23 are respectively connected to the oil inlet port 24 and the oil return port 25 on the stationary outer shell through the rotating inner core, so as to maintain the continuous circulation of the heat conduction fluid when the screw spindle 8 is rotating.

[0026] In this embodiment, by adopting a concentric pipeline layout and a multi-channel rotary joint 10, even when the screw spindle 8 is in a dynamic working environment of high-speed rotation, it is still possible to maintain a continuous path for the heat transfer fluid to enter the screw center from the external temperature control system 11 and circulate back, thus ensuring the stability and real-time performance of the temperature regulation of the core of the compression section 12.

[0027] In one embodiment, the permanent antistatic PC material preparation system has a sealing ring 17 that is a radially adaptive combined seal.

[0028] In this embodiment, the radially adaptive composite seal refers to a composite sealing ring 17 comprising an elastic tension inner ring and a wear-resistant outer ring, the outer diameter of which can expand or contract accordingly with the radial changes of the mounting base. In this embodiment, since the thermally responsive sleeve 13 will generate radial displacement during operation, traditional rigid sealing rings are prone to failure due to gap changes. By using the radially adaptive composite seal, the thermally responsive sleeve 13 can maintain a tight fit with the mating surface of the screw spindle 8 throughout its entire stroke as it expands and contracts with temperature, effectively preventing high-pressure melt from entering the mating gap between the thermally responsive sleeve 13 and the screw spindle 8, avoiding the thermally responsive sleeve 13 from jamming and losing its movement capability, and ensuring the long-term reliability of the variable compression ratio mechanism.

[0029] In one embodiment, the permanent antistatic PC material preparation system has a thermally responsive sliding sleeve 13 made of an alloy material with a high coefficient of thermal expansion. As an alternative embodiment, a manganese-copper alloy or an iron-nickel alloy may be selected for the high coefficient of expansion. Furthermore, the thermally responsive sliding sleeve 13 has several axially distributed slits 26 along its circumference, and each segment of the thermally responsive sliding sleeve 13 is repositioned by an elastic connector.

[0030] In this embodiment, the axial slit 26 refers to the gap cut parallel to the screw axis. Since a complete cylindrical sleeve is constrained by circumferential stress when heated, its outward radial expansion is extremely limited and prone to fatigue fracture. Therefore, by setting circumferentially evenly distributed axial slits 26, the sleeve is structurally divided into multiple segments, releasing the constraint of circumferential thermal stress. This allows the volume expansion of the high thermal expansion coefficient alloy after heating to be entirely converted into controllable radial displacement. The elastic connector ensures that when the oil temperature decreases, each segment of the sleeve can quickly retract inward and return to its original position, achieving reciprocating adjustment of the root diameter.

[0031] In one embodiment, the permanent antistatic PC material preparation system further includes an embedded insulating bushing for its ERT sensor 6, with the electrode array 7 arranged circumferentially at equal intervals on the inner wall of the insulating bushing.

[0032] In this embodiment, the injection molding machine's barrel 4 and nozzle are typically made entirely of metal. If the high-frequency electrode is in direct contact with the metal, the excitation current will be conducted along the wall of the metal barrel 4 and short-circuit, failing to effectively penetrate into the melt. Therefore, by adding an embedded insulating bushing as a mounting carrier for the electrode array 7, the electrodes are spatially isolated from the metal barrel 4, forcing all the field lines of the excitation current to pass through the internal PC melt.

[0033] In one embodiment, the permanent antistatic PC material preparation system includes an ultrasonic auxiliary device 18 comprising a transducer annularly disposed around the outer periphery of the melt channel 19 and an amplitude transformer communicating with the inner cavity of the melt channel 19, wherein the end of the amplitude transformer extends to the central region of the melt channel 19.

[0034] In this embodiment, the energy of conventional ultrasonic devices, which are typically attached to the pipe wall, attenuates significantly when penetrating viscous melts, often resulting in an energy dead zone in the central region. By extending the amplitude transformer directly through the pipe wall to the center of the flow channel, energy can be uniformly diffused from the inside out across the entire flow channel cross-section. This deep intervention within the melt allows antistatic components such as carbon nanotubes to re-establish a continuous conductive network before final solidification in the mold.

[0035] In one embodiment, in this permanent antistatic PC material preparation system, when the impedance fluctuation fed back by the ERT sensor 6 exceeds a preset threshold, the controller 20 first adjusts the speed of the drive motor 21 to perform instantaneous shear force compensation, and then adjusts the oil temperature through the temperature control system 11 to correct the screw compression ratio.

[0036] In this embodiment, the change in oil temperature causes a time delay in the thermal expansion and contraction of metal components. Therefore, when a break in the conductive path is detected, the system prioritizes reducing the motor speed. This is achieved by reducing the linear velocity of the screw spindle 8 to instantaneously reduce the shear rate. During this buffer period, the thermally responsive sleeve 13 driven by the temperature control system 11 gradually contracts to its final position, completing the reconstruction to reduce shear rate.

[0037] In one embodiment, the permanent antistatic PC material preparation system has a friction-reducing coating on the inner wall of the compression section 12 of the barrel 4 to reduce the frictional resistance between the thermally responsive sleeve 13 and the inner wall of the barrel 4 during radial displacement.

[0038] In this embodiment, a friction-reducing coating is provided on the inner wall of the barrel 4, which reduces the resistance coefficient of friction between the outer circumferential spiral of the thermal response sleeve 13 under high pressure melt extrusion and the inner wall of the barrel 4, avoids jamming during the expansion of the thermal response sleeve 13, and extends the service life of key components of the equipment.

[0039] In one embodiment, the permanent antistatic PC material preparation system has a hardened threaded surface of the outer peripheral conveying spiral 14, which has a hardness higher than the surface hardness of the screw spindle 8.

[0040] In this embodiment, wear is more concentrated in the dynamically controlled region where the compression ratio changes. The wear life is improved by individually and locally hardening the outer peripheral conveying spiral 14 on the sleeve.

[0041] In one embodiment, the permanent antistatic PC material preparation system has a feeding drive device 27 of the mixing unit 1 electrically connected to the controller 20, and the amount of antistatic additive added is adjusted in real time according to the melt composition uniformity monitored by the ERT sensor 6.

[0042] In this embodiment, since the impedance tomography spectrum fed back by the ERT sensor 6 can reflect the spatial distribution variance of conductivity on the cross-section, i.e., the dispersion uniformity, when the variance is too large and exceeds the compensation limit of the downstream adjusting screw compression ratio or ultrasonic intervention, the system controller 20 will feed this signal back to the front-end mixing unit 1. By finely adjusting the rotation speed of the feeding drive device 27 to appropriately increase the feeding ratio of antistatic masterbatch, cross-unit feedforward compensation control is achieved to control the quality of the final molded product.

[0043] The specific embodiments described above further illustrate the inventive purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A permanent antistatic PC material preparation system, characterized in that, It includes a mixing unit, an extrusion granulation unit, and an injection molding unit connected in sequence; The injection molding unit includes a barrel, a screw assembly rotatably disposed inside the barrel, and an ERT sensor disposed at the nozzle at the end of the barrel. The ERT sensor includes an electrode array for online acquisition of electrical impedance tomography data of the melt passing through the nozzle. The screw assembly includes a screw spindle with a longitudinally penetrating inner core heat conduction oil channel. This inner core heat conduction oil channel is connected to an external temperature control system via a connector. The barrel has a compression section. A segmented thermal response sleeve is fitted around the outer periphery of the screw spindle within the compression section. An outer peripheral conveying spiral is provided on the outer surface of the thermal response sleeve. The pitch and helix angle of the outer peripheral conveying spiral are consistent with those of the screw spindle to form a continuous melt conveying path. The thermal response sleeve is circumferentially fixed to the screw spindle via an axial positioning key and axially limited by a fixing ring. Sealing rings are provided at both ends of the mating surface between the thermal response sleeve and the screw spindle. The thermal response sleeve responds to changes in the fluid temperature within the inner core heat conduction oil channel by generating radial expansion displacement, thereby dynamically adjusting the compression ratio by changing the effective root diameter of the screw assembly within the compression section. The injection molding unit also includes an ultrasonic auxiliary device, which is located on the melt flow channel after the nozzle at the end of the barrel and before the mold cavity, and is used to apply high-frequency vibration to the melt before it enters the mold cavity. It also includes a controller, which is electrically connected to the ERT sensor, the temperature control system, the ultrasonic auxiliary device, and the drive motor of the screw assembly. The controller controls the temperature control system in real time to adjust the oil temperature to dynamically adjust the compression ratio based on the electrical impedance tomography data fed back by the ERT sensor, and synchronously adjusts the output power of the ultrasonic auxiliary device and the drive motor.

2. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The joint is a multi-channel rotary joint, which includes a fixed stationary outer shell and a rotating inner core that rotates synchronously with the screw spindle. The heat conduction oil passage of the inner core includes an oil inlet pipe located at the center of the screw spindle and a concentric oil return pipe fitted around the outer periphery of the oil inlet pipe. The oil inlet pipe and the oil return pipe are respectively connected to the oil inlet and oil return port on the stationary outer shell through the rotating inner core, so as to maintain the continuous circulation of the heat conduction fluid when the screw spindle is rotating.

3. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The sealing ring is a radially adaptive combined seal.

4. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The thermally responsive sliding sleeve is made of an alloy material with a high coefficient of thermal expansion, and the thermally responsive sliding sleeve has several axial slits evenly distributed along the circumference. Each segment of the thermally responsive sliding sleeve is reset by an elastic connector.

5. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The ERT sensor also includes an embedded insulating bushing, and the electrode array is arranged circumferentially at equal intervals on the inner wall of the bushing.

6. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The ultrasonic-assisted device includes a transducer arranged in a ring around the outer periphery of the melt channel and an amplitude transformer communicating with the inner cavity of the melt channel, with the end of the amplitude transformer extending to the central region of the melt channel.

7. The permanent antistatic PC material preparation system according to claim 1, characterized in that, When the impedance fluctuation fed back by the ERT sensor exceeds a preset threshold, the controller first adjusts the speed of the drive motor to perform instantaneous shear force compensation, and then adjusts the oil temperature through the temperature control system to correct the screw compression ratio.

8. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The inner wall of the compression section of the barrel is provided with a friction-reducing coating to reduce the frictional resistance between the thermally responsive sliding sleeve and the inner wall of the barrel during radial displacement.

9. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The threaded surface of the outer peripheral conveying spiral is hardened, and its hardness is higher than that of the surface hardness of the screw spindle.

10. The permanent antistatic PC material preparation system according to claim 1, characterized in that, The feeding drive device of the mixing unit is electrically connected to the controller, and the amount of antistatic additive added is adjusted in real time according to the melt composition uniformity monitored by the ERT sensor.

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