Fluoroplastic foaming extrusion production system and use method thereof

Abstract

The invention relates to a fluoroplastic foaming extrusion production system and a use method thereof, and belongs to the technical field of wire and cable manufacturing equipment. Comprising a movable disc pay-off machine, a front traction machine, a front-section double-shaft diameter measuring instrument, an oven preheater, a vacuum filling machine, an integrated foaming extrusion unit, a vacuumizing device, a rear-section double-shaft diameter measuring instrument, a movable warm water tank, a fixed warm water tank, an in-water capacitance meter, a first spraying water tank, a water blower, a four-shaft eccentric meter, a rear traction machine and a spark machine which are sequentially arranged in the direction of a production line. The system comprises an integrated foaming extrusion unit, a three-axis concave-convex instrument, a data display processing device, an analysis and prediction module, a control module, a second spraying water tank and a movable disc take-up machine, and the integrated foaming extrusion unit comprises a main machine extruder, a first inclined auxiliary machine extruder, a second inclined auxiliary machine extruder and a foaming machine head. According to the invention, high-precision stable production in the whole process can be realized, an extremely stable material flow foundation is provided for a production line, and the consistency of the size and the performance of a product is fundamentally guaranteed.

Description

Technical Field

[0001] This invention relates to the field of wire and cable manufacturing equipment technology, and in particular to a fluoroplastic foaming extrusion production system and its usage method. Background Technology

[0002] In the field of high-frequency signal transmission cables, such as 5G communication, data centers, aerospace and medical equipment, extremely high requirements are placed on the transmission frequency, diameter, high temperature resistance and low signal attenuation of the cables. Using fluoroplastics (such as polytetrafluoroethylene propylene FEP) as insulation material and combining it with physical foaming technology to reduce its dielectric constant is a key path to achieve high performance and miniaturization of cables.

[0003] However, the stable production of such ultra-fine, high-foaming, and low-eccentricity fluoroplastic foamed cables faces the following specific technical bottlenecks:

[0004] First, the problem of damage to ultra-fine conductors: For ultra-fine conductors of 32-25AWG, traditional static reel unwinding will introduce torsional stress due to the change in the angle between the reel and the production line, while conventional traction wheel sets are prone to crushing or scratching the conductor surface, resulting in deterioration of electrical performance.

[0005] Secondly, there is the issue of long-term stability in high-precision foamed extrusion: the uniformity and concentricity of physically foamed insulation are crucial to the high-frequency performance of cables. Existing three-machine co-extrusion systems typically install the extruder independently on the ground, connected to the die head via a long flow channel. This method presents initial alignment difficulties, and during operation, due to differences in the thermal expansion coefficients of various components and foundation settlement, uncontrollable micron-level drift can easily occur between the die head and the extruder flow channel, making it difficult to maintain ultra-high concentricity (e.g., eccentricity <3%) of the sub-millimeter level insulation layer over the long term.

[0006] Third, the system suffers from low intelligence and lagging control: existing production lines have many isolated testing units, relying on manual spot checks and offline adjustments for quality control. This is particularly true for the critical indicator of foaming degree, where the lack of online, continuous testing methods and real-time closed-loop control leads to poor product consistency and high material consumption.

[0007] In summary, existing technologies lack a high-end fluoroplastic foamed cable production line that can systematically solve the problems of ultra-fine conductor processing damage, high-precision foamed insulation extrusion, long-term operational stability, and intelligent closed-loop control. This paper proposes a fluoroplastic foaming extrusion production system and its application method. Summary of the Invention

[0008] This invention provides a production system that optimizes the entire process from unwinding and extrusion to inspection and winding. The system achieves constant tension release of ultra-fine conductors through a moving unwinding machine equipped with a bottom diameter measurement; solves the problem of drift caused by thermal expansion by an extruder unit integrated into a rigid platform and equipped with a multi-degree-of-freedom fine-tuning connection structure, ensuring high concentricity; and achieves real-time intelligent control of key quality through closed-loop control of foaming degree based on online measurement of underwater capacitance and closed-loop control of outer diameter based on a diameter measuring instrument.

[0009] The present invention provides the following solution to the above-mentioned technical problems: a fluoroplastic foaming extrusion production system and its usage method, comprising, sequentially arranged along the production line direction, a moving disc feeder, a front traction machine, a front biaxial diameter gauge, an oven preheater, a vacuum filler, an integrated foaming extrusion unit, a vacuum device, a rear biaxial diameter gauge, a movable warm water tank, a fixed warm water tank, an underwater capacitance meter, a first spray water tank, a water blower, a four-axis eccentricity meter, a rear traction machine, an EDM machine, a three-axis concave-convexity meter, a data display and processing device, an analysis and prediction module, a control module, a second spray water tank, and a moving disc take-up machine, characterized in that: the integrated foaming extrusion unit comprises a main extruder, a first inclined auxiliary extruder, a second inclined auxiliary extruder, a foaming die head, and a rigid integrated platform;

[0010] The axis of the main extruder is collinear with and directly connected to the axis of the central flow channel of the foaming head; the No. 1 inclined auxiliary extruder and the No. 2 inclined auxiliary extruder are obliquely connected to the side of the foaming head through a multi-degree-of-freedom mechanical connection structure.

[0011] The system is also equipped with a control system and a system power configuration module;

[0012] The moving reel take-up machine adopts a take-up reel active translation method for cable laying and a cable laying guide wheel fixed, and reserves a work position for AGV automatic guided transport vehicle operation;

[0013] The system also includes a gas supply and detection system for providing nitrogen to the foaming die head, a stainless steel double-layer insulated hopper, a high-temperature melt pressure transmitter connected to the stainless steel double-layer insulated hopper of the extruder, and a first nitrogen injection needle and a second nitrogen injection needle inserted into the foaming die head. The first nitrogen injection needle and the second nitrogen injection needle are not used at the same time and are respectively suitable for different specifications of wire.

[0014] The data output terminals of the underwater capacitance meter, four-axis eccentric meter, EDM machine, and three-axis concave-convex meter are connected to the data display and processing device. The analysis and prediction module and the control module perform process analysis and closed-loop control based on the data.

[0015] Based on the above technical solution, the present invention can be further improved as follows.

[0016] Furthermore, the moving disc pay-off machine adopts a moving disc structure in which the pay-off disc rotates synchronously driven by the drive device. The moving disc pay-off machine is equipped with a bottom diameter measuring device for real-time measurement of the bottom diameter of the pay-off disc winding. This bottom diameter measuring device is connected to the control system signal of the system. The moving disc pay-off machine is equipped with carbon brushes to ground the conductor, which improves the stability of the pay-off section of the production line, avoids interference, and reduces the interference caused by tension fluctuations to subsequent preheating, extrusion and other processes. This lays a solid foundation for the production of high-quality foamed cables, while improving the utilization rate of raw materials and reducing wire breakage and start-up waste.

[0017] Furthermore, the driving wheels of the front and rear traction machines have a high-hardness wear-resistant coating, and the driven wheels are made of a low-friction coefficient material, which doubles the protection of the physical integrity of the cable during the traction process. This is especially suitable for foamed fluoroplastic cables that require high surface smoothness, extends the maintenance cycle of the traction wheels, and reduces consumable costs.

[0018] Furthermore, both the front and rear traction machines are dual-wheel traction machines. The driving wheel is a metal wheel with a tungsten carbide coating, while the driven wheel is a bakelite wheel made of phenolic resin laminate. The mounting axis of the driven wheel is inclined relative to the mounting axis of the driving wheel, allowing the cable to be separated into multiple windings through the inclination of the guide wheel, eliminating the need for guidance and separation through the wheel groove edge, thus reducing damage to the cable. The traction motor directly drives the driving wheel through a reducer and is equipped with a counterweight swing arm mechanism and a tension sensor, improving the tension control accuracy in the middle section of the production line (after extrusion) and before take-up. This effectively suppresses cable vibration and serpentine movement in the cooling tank, which is crucial for ensuring the uniformity of geometric dimensions (such as eccentricity) and capacitance, achieving refined tension control throughout the entire process from wire feeding to take-up.

[0019] Furthermore, in the integrated foaming extruder unit, the multi-degree-of-freedom mechanical connection structure enables independent fine-tuning and locking of the No. 1 and No. 2 inclined auxiliary extruders relative to the foaming die head in six degrees of freedom: vertical, horizontal, and three linear directions, as well as rotational angles around three coordinate axes. This eliminates flow channel misalignment caused by processing errors, installation errors, or differences in thermal expansion, avoiding dead zones and melt stagnation at these points. This is particularly important for processing heat-sensitive and easily decomposed fluoroplastics. Simultaneously, this structure facilitates initial installation and commissioning, as well as recalibration after subsequent maintenance, ensuring the smoothness and uniformity of multi-channel melt convergence. This is a key mechanical guarantee for obtaining a stable foamed structure and uniform insulation layer thickness.

[0020] Furthermore, the extrusion screws of the main extruder, the first inclined auxiliary extruder, and the second inclined auxiliary extruder are all driven by motors; the barrels of the main extruder, the first inclined auxiliary extruder, and the second inclined auxiliary extruder are provided with sliding support structures in the axial direction that allow free expansion and movement after heating, preventing barrel deformation, screw jamming, or bearing damage caused by the huge internal stress generated by thermal expansion, ensuring the long-term operational reliability and lifespan of the equipment under high-temperature operation, and ensuring the stability of the plasticizing process.

[0021] Furthermore, the moving reel take-up machine is equipped with a wire-catching hook device for automatically capturing and guiding the cable at the start of take-up, which eliminates the manual threading and guiding steps required by traditional take-up machines, improves production efficiency, reduces the labor intensity and safety risks of operators (avoiding contact with moving parts), and realizes fully automated start and stop of the take-up process, making it an indispensable automation interface in intelligent manufacturing units.

[0022] Furthermore, the gas supply and detection system is a nitrogen pressurization and flow detection system; the control module receives measurement signals from the underwater capacitance meter and the downstream biaxial diameter measuring instrument, and achieves closed-loop control of the insulation layer foaming degree and outer diameter by adjusting the nitrogen flow rate and the extruder screw speed. This realizes online real-time automatic control of the core product quality indicators (foaming degree and outer diameter), replacing the traditional mode that relies on manual experience and delayed adjustments, greatly improving the consistency, stability and pass rate of the product, and having direct economic benefits in reducing material consumption (such as saving fluoroplastics by optimizing the foaming degree).

[0023] Furthermore, the analysis and prediction module performs time-domain to frequency-domain transformation analysis on the data detected by the four-axis eccentricity gauge and the three-axis concave-convexity gauge. This allows it to identify and predict periodic quality fluctuation trends during the production process and accurately pinpoint the source of periodic quality defects. For example, fluctuations in frequency with the screw speed may originate from the extruder, fluctuations in frequency with the traction wheel may originate from the traction system, and fluctuations in frequency with the take-up reel rotation may originate from take-up oscillation. By identifying these characteristic frequencies, the system can provide early warnings of potential anomalies in specific equipment components (such as screw wear, bearing damage, and uneven transmission), thereby achieving a leap from "post-event detection" to "pre-event prediction" and "root cause diagnosis," guiding preventative maintenance, reducing unplanned downtime, and continuously optimizing process stability.

[0024] The beneficial effects of this invention are as follows: This invention provides a fluoroplastic foaming extrusion production system and its usage method, which has the following advantages:

[0025] 1. It can achieve high-precision and stable production throughout the entire process, from constant tension wire feeding and precision traction to direct drive speed stabilization of the extruder, providing an extremely stable material flow (conductor and melt) foundation for the production line, fundamentally ensuring the consistency of product size and performance.

[0026] 2. It can improve product quality and pass rate. Precise mechanical alignment and stable process conditions ensure uniform foaming structure and accurate control of insulation layer thickness (eccentricity). Closed-loop control realizes online real-time automatic adjustment of foaming degree and outer diameter. The fluctuation range of key product indicators is extremely small. Optimized traction wheel and tension control effectively protect the surface smoothness of the cable.

[0027] 3. Enhance equipment reliability and service life. The design of wear-resistant traction wheels, screw direct drive structure, and barrel sliding support reduces wear, overload and thermal stress damage of key components, lowers the failure rate and extends the equipment overhaul cycle.

[0028] 4. Improve the level of production automation and intelligence. From automatic wire capture and winding to AGV station reservation, the wire winding and unwinding process has been automated. Based on closed-loop control of multi-sensor data, the core process has been intelligently adjusted. The analysis and prediction module has achieved the effect of "detection" to "diagnosis" and "prediction", providing data support for intelligent manufacturing and preventive maintenance.

[0029] 5. It can reduce overall production costs. The high pass rate directly reduces waste loss. Precise foaming degree control optimizes the consumption of expensive fluoroplastic raw materials. Improved equipment reliability reduces downtime and maintenance time and costs. Automation reduces reliance on skilled operators and labor costs.

[0030] 6. It is particularly suitable for processing high-performance materials. The low friction, anti-retention, anti-thermal decomposition, and high stability design of the entire system are especially suitable for the precision processing requirements of heat-sensitive and high-value materials such as fluoroplastics, and can produce high-quality foamed insulation products that meet high-end cable standards.

[0031] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail below with reference to the accompanying drawings. Attached Figure Description

[0032] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0033] Figure 1 This is a schematic diagram of a fluoroplastic foaming extrusion production system and its usage method according to an embodiment of the present invention;

[0034] Figure 2 A top view of a fluoroplastic foaming extrusion production system and its usage method provided in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the front section of a fluoroplastic foaming extrusion production system and its usage method according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of the downstream section of a fluoroplastic foaming extrusion production system and its usage method according to an embodiment of the present invention;

[0037] Figure 5 This is a top view of the front section of a fluoroplastic foaming extrusion production system and its usage method provided in an embodiment of the present invention.

[0038] Figure 6 This is a top view of the rear section of a fluoroplastic foaming extrusion production system and its usage method provided in an embodiment of the present invention.

[0039] The attached diagram lists the components represented by each number as follows:

[0040] 1. Moving disc wire feeding machine; 2. Front-end biaxial diameter gauge; 3. Oven preheater; 4. Vacuum filling machine; 5. Foaming die head; 6. Front traction machine; 7. Vacuum pumping device; 8. High-temperature melt pressure transmitter; 9. Stainless steel double-layer insulated hopper; 10. No. 1 nitrogen injection needle; 11. No. 2 nitrogen injection needle; 12. Main extruder; 13. No. 1 inclined auxiliary extruder; 14. No. 2 inclined auxiliary extruder; 15. Gas supply and detection system; 16. 17. Rear-end dual-axis diameter measuring instrument; 18. Movable warm water tank; 19. Control system; 20. Power configuration; 21. Fixed warm water tank; 22. Underwater capacitance meter; 23. No. 1 spray tank; 24. Water blower; 25. Four-axis eccentricity meter; 26. Rear traction machine; 27. EDM machine; 28. Three-axis concave-convexity meter; 29. ​​Data display and processing device; 30. Analysis and prediction module; 31. Control module; 32. No. 2 spray tank; 33. Moving disc winding machine. Detailed Implementation

[0041] The following is in conjunction with the appendix Figure 1-5 The principles and features of the present invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0042] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] like Figure 1-6 As shown, the present invention provides a fluoroplastic foaming extrusion production system and its usage method. The system is sequentially integrated along the production line direction (cable travel direction) with the following components: a moving disc wire feeding machine 1, a front traction machine 6, a front biaxial diameter gauge 2, an oven preheater 3, a vacuum filling machine 4, an integrated foaming extrusion unit, a vacuum pumping device 7, a rear biaxial diameter gauge 16, a movable warm water tank 17, a fixed warm water tank 20, an underwater capacitance meter 21, a first spray water tank 22, a water blower 23, a four-axis eccentricity meter 24, a rear traction machine 25, an EDM machine 26, a three-axis concave-convexity meter 27, a data display and processing device 28, an analysis and prediction module 29, a control module 30, a second spray water tank 31, and a moving disc wire taking-up machine 32. The entire system is uniformly coordinated by the control system 18 and driven by the system power configuration module 19.

[0045] 1. Wire feeding and pre-processing section: The moving reel wire feeding machine 1 is used to release the cable conductor. In a preferred embodiment, the moving reel wire feeding machine 1 adopts an active structure in which the wire feeding reel is driven to rotate synchronously by a drive device (such as a servo motor), replacing the traditional passive wire feeding. The machine is also equipped with a bottom diameter measuring device (such as a laser rangefinder sensor) to monitor the winding bottom diameter of the remaining conductor on the wire feeding reel in real time and transmit the signal to the control system 18 in real time. The control system 18 dynamically adjusts the wire feeding speed according to the bottom diameter change, thereby realizing constant tension or programmed tension control throughout the entire process from the start to the end of wire feeding, effectively avoiding conductor vibration caused by sudden tension changes, and laying the foundation for subsequent precision processing.

[0046] After the conductor is led out by the driven coil feeding machine 1, it first passes through the front biaxial diameter measuring instrument 2 to monitor the conductor diameter online, ensuring that the conductor specifications entering the production line meet the requirements. Then, the conductor enters the oven preheater 3 for preheating to remove surface moisture and increase its temperature, which is beneficial for subsequent bonding with molten fluoroplastic. The preheated conductor is pulled into the extrusion area by the front traction machine 6.

[0047] 2. Traction mechanism: The front traction machine 6 and the rear traction machine 25 are responsible for providing stable and precise traction force at key positions on the production line. In one specific embodiment, both the front and rear traction mechanisms are dual-wheel traction machines. The driving wheel is a metal wheel (such as a steel wheel) with a high-hardness, high-wear-resistant tungsten carbide coating on its surface to ensure the stability of the groove shape and traction speed during long-term use. The driven wheel is made of phenolic resin laminate material (i.e., bakelite), which has a low coefficient of friction and a certain degree of elasticity, effectively protecting the cable surface from scratches. In particular, the mounting axis of the driven wheel is inclined at an angle relative to the mounting axis of the driving wheel, so that the cable can be separated into multiple windings through the inclination of the guide wheel, rather than being guided and separated by the edge of the wheel groove, thereby effectively reducing damage to the cable.

[0048] The traction motor directly drives the drive wheel through the reducer, which responds quickly. The traction machine is also equipped with a counterweight swing arm mechanism and a tension sensor integrated on the swing arm. This mechanism can sense the actual tension of the cable in real time and feed the signal back to the control system 18 to form a local tension closed loop, thereby accurately controlling the tension in the middle section of the production line (after extrusion) and before take-up, and suppressing the cable's snakeing and shaking in the cooling water tank.

[0049] 3. An integrated foaming extrusion unit is installed on a rigid integrated platform 33 to ensure the stability of the overall structure. The unit includes a main extruder 12, two inclined auxiliary extruders (No. 13 and No. 24) and a foaming head 5.

[0050] The axis of the main extruder 12 is strictly collinear with the axis of the central flow channel of the foaming head 5 and is directly rigidly connected by a flange to provide melt for the main insulation layer. The two auxiliary extruders are obliquely connected to the side of the foaming head 5 through a multi-degree-of-freedom mechanical connection structure. This connection structure has six degrees of freedom for fine adjustment, that is, it allows the auxiliary extruders to be independently and precisely adjusted relative to the head in three linear directions (up and down, front and back, left and right) and rotation angles around three coordinate axes. After adjustment, they can be fixed by a locking mechanism. This design completely solves the problem of precise alignment of multi-flow channel docking and avoids flow channel misalignment and melt stagnation dead angles caused by processing or installation errors. This is crucial for processing heat-sensitive fluoroplastics.

[0051] One possible implementation of the multi-degree-of-freedom mechanical connection structure is as follows: between the connecting flange of the auxiliary extruder and the foaming head 5, three sets of precision linear slides arranged perpendicularly to each other are set to control the linear displacement in the up, down, left, right, and front-back directions respectively; at the same time, three sets of rotary adjustment mechanisms with precision arc scales are set to control the rotation angle around the three coordinate axes respectively. Each degree of freedom is equipped with a high-rigidity locking bolt, which can be firmly locked after fine adjustment to ensure positional stability under high temperature and vibration conditions.

[0052] All extruder screws are driven by electric motors, eliminating the traditional gear reducer and achieving backlash-free, high-response speed control. This ensures extreme stability in plasticizing and extrusion volume. Meanwhile, each extruder barrel is equipped with a sliding support structure in the axial direction (e.g., through a slider and guide rail), allowing the barrel to expand freely in the axial direction after heating, releasing thermal stress, preventing barrel deformation and screw jamming, and ensuring the long-term reliability of the equipment.

[0053] Each extruder is equipped with a stainless steel double-layer insulated hopper 9 for storing and supplying fluoroplastic raw materials. The hopper is connected to a high-temperature melt pressure transmitter 8 for monitoring the plasticizing state. The gas required for foaming (preferably nitrogen) is provided by a gas supply and detection system 15 (including a booster pump, pressure stabilizing valve, mass flow controller, etc.) and is precisely injected into the melt flow channel in the foaming head 5 through nitrogen injection needle 10 and nitrogen injection needle 11. The vacuum filler 4 is used to automatically and tightly transport fluoroplastic particles to each hopper, reducing pollution and moisture absorption.

[0054] 4. Cooling, Detection and Control Section: After the wire core covered with foamed insulation comes out of the machine head, it first passes through the vacuum device 7 for shaping, and then enters the cooling stage. First, it passes through the movable warm water tank 17 and the fixed warm water tank 20 for graded warm water cooling to control the crystallization process and optimize the foaming structure. In the water stage, the underwater capacitance meter 21 measures the capacitance value of the insulation layer online. This value indirectly reflects the degree of foaming (dielectric constant).

[0055] Subsequently, the cable is further cooled by the No. 1 spray water tank 22 and the surface is dried by the water blower 23. After drying, the cable passes through the four-axis eccentricity tester 24 (to measure the uniformity of the insulation layer thickness), the spark tester 26 (to perform withstand voltage test), and the triaxial convexity tester 27 (to detect the flatness of the cable outer surface). The data output terminals of all the testing instruments are connected to the data display and processing device 28 for centralized display and recording.

[0056] The control module 30 receives real-time measurement values ​​from the underwater capacitance meter 21 (foaming degree signal) and the downstream biaxial diameter measuring instrument 16 (outer diameter signal), compares them with the set values, and dynamically adjusts the nitrogen flow rate of the gas supply and detection system 15 (to control the foaming degree) and the screw speed of the main extruder 12 (to control the outer diameter in conjunction with the outer diameter traction speed) through PID and other control algorithms, so as to realize online automatic control of the two most critical indicators of product quality.

[0057] The analysis and prediction module 29 performs time-domain-frequency domain transformation analysis, such as Fast Fourier Transform (FFT), on the time-domain fluctuation data detected by the quad-axis eccentricity meter 24 and the triaxial concave-convexity meter 27 to identify characteristic frequencies in the fluctuation signals. For example, fluctuations with the same frequency as the screw rotation may indicate extruder problems, while fluctuations with the same frequency as the traction wheel may originate from the traction system. Through this analysis, the system can provide early warnings of potential periodic equipment anomalies (such as bearing wear and uneven transmission), enabling predictive maintenance and process root cause diagnosis.

[0058] 5. Take-up section: After the cable is finally pulled by the rear traction machine 25, it enters the second spray water tank 31 for final cooling and cleaning, and then is wound up by the rotating take-up machine 32. This take-up machine uses "active translation of the take-up reel" for cable arrangement, while the positioning guide wheel is fixed. This method makes the cable tension more uniform. The take-up machine is equipped with a cable-catching hook device, which can automatically capture the cable end at the beginning of the winding and guide it to the take-up reel, realizing fully automatic cable threading without manual intervention. In addition, the take-up machine area has reserved a standard AGV (Automated Guided Vehicle) operating position, which facilitates the fully automatic loading, unloading and transportation of the take-up reel, integrating it into the intelligent factory logistics system.

[0059] The specific working principle and usage method of this invention are as follows:

[0060] S1: Wire feeding and conductor pretreatment: The wire reel containing the ultra-fine conductor is installed on the moving reel wire feeding machine 1. The system is started, and the servo drive device of the moving reel wire feeding machine 1 actively drives the wire feeding reel to rotate synchronously, realizing active wire feeding. Its bottom diameter measuring device (laser range sensor) monitors the diameter of the remaining conductor on the wire feeding reel in real time and feeds the data back to the control system 18 (an integrated control system based on industrial PC and PLC).

[0061] The control system dynamically adjusts the speed of the unwinding servo motor based on the real-time bottom diameter and a preset tension model (e.g., using an indirect tension control algorithm to approximately maintain constant tension by keeping the product of linear speed and roll diameter constant), ensuring stable tension throughout the entire unwinding process from start to finish.

[0062] The conductor then passes through the front-end biaxial diameter gauge 2 (non-contact laser diameter gauge) for online diameter monitoring and recording, and then enters the oven preheater 3 (using quartz tube or hot air circulation type for precise temperature control) to remove surface moisture and preheat to the set temperature (e.g., 150-200℃).

[0063] S2: The conductor is pulled into the machine head. The preheated conductor is pulled by the front traction machine 6. The driving wheel (tungsten carbide coating) of the traction machine is directly driven by a servo motor through a precision reducer. The driven wheel (bakelite wheel) provides constant clamping force through a counterweight swing arm mechanism. The tension sensor on the swing arm measures the conductor tension in real time.

[0064] Control logic: This tension signal forms a local closed loop, and the control system can fine-tune the forward traction speed or the wire feeding speed to ensure that the conductor is accurately fed into the central conductor guide tube of the foaming head 5 with extremely stable tension.

[0065] S3: Material supply and foaming agent injection. Fluoroplastic granules (such as FEP) are automatically and tightly conveyed to the stainless steel double-layer insulated hoppers 9 of each extruder through the vacuum filling machine 4. At the same time, the gas supply and detection system 15 (including nitrogen source, booster pump, precision pressure regulating valve and mass flow controller) is started to accurately pressurize and measure high-purity nitrogen.

[0066] Nitrogen gas is injected into the predetermined melt flow channel position of the foaming head 5 through nitrogen injection needle 10 and nitrogen injection needle 11 (with independent temperature control), and the high temperature melt pressure transmitter 8 connected below each extruder hopper 9 begins to monitor the plasticizing pressure.

[0067] S4: Co-extrusion foaming molding, the main extruder 12 (fluoroplastic foaming extruder, Φ30mm) and two inclined auxiliary extruders 13 and 14 (fluoroplastic foaming extruders, Φ20mm) start synchronously. The screws of each extruder are directly driven by servo motors, which melt and plasticize the fluoroplastics and mix them with the injected nitrogen in the foaming head 5.

[0068] The main melt forms the outer layer, the auxiliary melt forms the inner layer, nitrogen forms micropores in a specific layer, multiple melts precisely converge in the die head and together coat the conductor passing through the center to form an insulating layer with a specific cell structure (such as skin-bubble-skin structure). The entire integrated foaming extruder is installed on a rigid platform 33 and long-term centering accuracy is ensured by a six-degree-of-freedom fine-tuning mechanical structure.

[0069] S5: Shaping, Cooling and Online Capacitance Testing

[0070] Steps: The coated wire core is first pre-shaped by vacuum device 7 (connected to a vacuum pump, providing a negative pressure environment at the machine head outlet), and then immediately put into the active warm water tank 17 (the water temperature is usually controlled at 70-90℃) for the first stage of slow cooling in order to control the crystallization process of fluoroplastics and optimize the cell structure.

[0071] Testing: The cable is then placed in a fixed warm water bath 20 for further cooling. During this stage, a capacitance meter 21 in the water continuously measures the capacitance value of the insulation layer online.

[0072] Principle: Based on the capacitance formula

[0073]

[0074] (Where C is capacitance, ε is dielectric constant of insulating material, D is outer diameter of insulation, and d is conductor diameter), when conductor diameter d and outer diameter D are known or monitored simultaneously, capacitance value C directly reflects the equivalent dielectric constant ε of foamed insulation layer, thus indirectly and continuously reflecting the degree of foaming;

[0075] Subsequent processing: The cable is then further cooled by the No. 1 spray water tank 22 and the surface moisture is dried by the water blower 23 (such as using a vortex tube or centrifugal fan);

[0076] S6: Multi-dimensional quality inspection and intelligent closed-loop control, the dried cables are passed through the following order;

[0077] Quad-axis eccentricity meter 24: measures the thickness of the insulation layer in four directions, calculates and outputs the eccentricity value;

[0078] The rear tractor unit 25 (with the same structure and control as the front tractor unit) provides traction.

[0079] EDM 26: Apply high voltage (e.g., 3-5kV) to check for defects such as pinholes and breaks in the insulation layer;

[0080] Triaxial convexity meter 27: Detects the microscopic unevenness of the outer diameter of cables;

[0081] Data aggregation: All test data (capacitance, eccentricity, spark breakdown signal, unevenness) are transmitted in real time to the data display and processing device 28 (industrial computer and SCADA monitoring software, such as WinCC or Indusoft).

[0082] Closed-loop control: Control module 30 executes two parallel PID (proportional-integral-derivative) closed-loop control algorithms;

[0083] Foaming degree control loop: The measured value of the capacitance meter 21 in the water is used as the process variable PV. It is compared with the set value SP. The deviation e is calculated by PID and outputs a control signal to dynamically adjust the set point of the mass flow controller in the gas supply and detection system 15, thereby changing the nitrogen injection flow rate.

[0084] The control module 30 adopts a proportional-integral-derivative (PID) control algorithm. For the foaming degree control loop: the target value of the capacitance of the underwater capacitance meter 21 is set to C_set, the measured value is C_meas, and the deviation is e_C = C_set - C_meas. The control module outputs a control signal to the mass flow controller in the gas supply and detection system 15 through PID calculation, and adjusts the nitrogen flow rate Q_N2 in real time to make e_C approach zero. For the outer diameter control loop: the principle is similar. The deviation e_D between the measured value and the target value of the outer diameter is used to output a control signal through PID calculation to adjust the screw speed of the main extruder 12, thereby adjusting the melt extrusion amount to stabilize the outer diameter.

[0085] Outer diameter control loop: The measured value of the rear dual-axis diameter measuring instrument 16 (located after the cooling tank, measuring the final outer diameter) is used as PV, compared with SP, and after PID calculation, the output control signal is used to adjust the screw speed of the main extruder 12 (or form a speed ratio adjustment with the front / rear traction machine speed), thereby controlling the extrusion amount to stabilize the outer diameter.

[0086] Advanced Analysis and Prediction: The analysis and prediction module 29 (a dedicated algorithm software running on an industrial PC, such as one developed based on MATLAB Runtime or Python) performs Fast Fourier Transform (FFT) analysis on the time-domain waveform signals acquired by the quad-axis eccentricity instrument 24 and the triaxial concavity and convexity instrument 27.

[0087] Convert the time-domain signal xt into a frequency-domain signal.

[0088]

[0089] (Discrete form is DFT), identifying significant characteristic frequency peaks in the spectrum;

[0090] The system has a built-in characteristic frequency library (such as the frequency corresponding to the main screw speed, the rotation frequency of the traction wheel, the rotation frequency of the take-up reel and its harmonics). When a peak matching these characteristic frequencies appears in the detected fluctuation spectrum, the module will issue an early warning, indicating possible fault sources (such as "extruder screw wear is accelerated" or "abnormal vibration of the traction wheel bearing"), thus enabling predictive maintenance.

[0091] The operation logic of the analysis and prediction module 29 includes the following steps: the data acquisition unit acquires the eccentric thickness fluctuation time-series signal x(t) output by the quad-axis eccentricity instrument 24 at a fixed frequency; the signal processing unit performs denoising and fast Fourier transform (FFT) on x(t) to obtain its frequency-amplitude spectrum; the feature extraction unit identifies significant peaks in the spectrum whose amplitude exceeds a set threshold (such as 5 times the amplitude of background noise) and records their frequency value f_peak; the diagnostic matching unit compares f_peak with a pre-stored feature frequency database, which stores the theoretical fundamental frequency and harmonics of each rotating component in the system, such as f_screw corresponding to the screw speed of the main extruder, f_pull corresponding to the drive wheel of the traction machine, f_wind corresponding to the rotation of the take-up reel, etc.; if |f_peak - n * f_screw| < Δf (n is an integer, Δf is the allowable frequency deviation), a diagnostic report 'periodic abnormality exists in the extruder screw or drive system' is generated, and a maintenance warning is issued. This function realizes equipment traceability of quality fluctuations and supports predictive maintenance.

[0092] S7: Final processing and automated winding. Qualified cables that pass the inspection are cooled and cleaned in the No. 2 spray water tank 31. The No. 2 spray water tank 31 is equipped with an underwater capacitance meter 21 to monitor the capacitance of the cables.

[0093] The cable enters the rotating take-up reel 32, where its hook device automatically captures the cable end and guides it to an empty take-up reel to begin winding. The take-up reel is driven by a servo motor to actively move and arrange the cable, ensuring that the cable is tightly and neatly arranged with uniform tension. Once the reel is full, the system pauses, and the AGV (Automated Guided Vehicle) drives into the reserved workstation according to the dispatch instructions, transports the full reel away, and replaces it with an empty reel, thus achieving fully automated operation of the entire process.

[0094] The overall effect of the equipment is as follows:

[0095] Production line speed: max 150m / min;

[0096] Suitable conductors: 32-25AWG;

[0097] Insulation outer diameter: φ0.53-1.1mm;

[0098] Insulation wall thickness: 0.165mm-0.323mm;

[0099] Extrusion material: FEP (foaming degree up to 50%);

[0100] It can be adapted to automatic forklift pallet retrieval, reducing manual labor.

[0101] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Content not described in detail in this specification is prior art known to those skilled in the art.

[0102] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A fluoroplastic foaming extrusion production system, comprising, sequentially arranged along the production line direction, a moving disc feeder (1), a front traction machine (6), a front biaxial diameter gauge (2), an oven preheater (3), a vacuum filler (4), an integrated foaming extrusion unit, a vacuum device (7), a rear biaxial diameter gauge (16), a movable warm water tank (17), a fixed warm water tank (20), an underwater capacitance meter (21), a first spray water tank (22), a water blower (23), a four-axis eccentricity meter (24), a rear traction machine (25), an EDM machine (26), a three-axis concave-convexity meter (27), a data display and processing device (28), an analysis and prediction module (29), a control module (30), a second spray water tank (31), and a moving disc take-up machine (32), characterized in that: The integrated foaming extrusion unit includes a main extruder (12), a first inclined auxiliary extruder (13), a second inclined auxiliary extruder (14), a foaming die head (5), and a rigid integrated platform (33). The axis of the main extruder (12) is collinear with and directly connected to the axis of the central flow channel of the foaming head (5); the first inclined auxiliary extruder (13) and the second inclined auxiliary extruder (14) are obliquely connected to the side of the foaming head (5) through a multi-degree-of-freedom mechanical connection structure. The system is also equipped with a control system (18) and a system power configuration module (19). The moving reel take-up machine (32) adopts a take-up reel active translation method for wire laying and fixed positioning guide wheel, and reserves a work position for AGV automatic guided transport vehicle operation; The system also includes a gas supply and detection system (15) for providing nitrogen to the foaming head (5), a stainless steel double-layer insulated hopper (9), a high-temperature melt pressure transmitter (8) connected to the stainless steel double-layer insulated hopper (9) of the extruder, and a first nitrogen injection needle (10) and a second nitrogen injection needle (11) inserted into the foaming head (5). The first nitrogen injection needle (10) and the second nitrogen injection needle (11) are not used at the same time and are respectively suitable for cables of different specifications. The data output terminals of the underwater capacitance meter (21), the four-axis eccentric meter (24), the EDM machine (26), and the three-axis concave-convex meter (27) are connected to the data display and processing device (28). The analysis and prediction module (29) and the control module (30) perform process analysis and closed-loop control based on the data.

2. The fluoroplastic foaming extrusion production system according to claim 1, characterized in that, The moving plate wire feeding machine (1) adopts a moving plate structure in which the wire feeding plate is driven to rotate synchronously by a drive device. The moving plate wire feeding machine (1) is equipped with a bottom diameter measuring device for real-time measurement of the bottom diameter of the wire feeding plate winding. The bottom diameter measuring device is connected to the control system (18) of the system via a signal.

3. The fluoroplastic foaming extrusion production system according to claim 1, characterized in that, The driving wheel surfaces of the front traction machine (6) and the rear traction machine (25) have a high-hardness wear-resistant coating, and the driven wheel is made of a low-friction coefficient material.

4. The fluoroplastic foaming extrusion production system according to claim 3, characterized in that, Both the front traction machine (6) and the rear traction machine (25) are dual-wheel traction machines. The driving wheel is a metal wheel with a tungsten carbide coating on its surface, and the driven wheel is a bakelite wheel made of phenolic resin laminate material. The mounting axis of the driven wheel is inclined at an angle relative to the mounting axis of the driving wheel. The traction motor directly drives the driving wheel through a reducer and is equipped with a counterweight swing arm mechanism and a tension sensor.

5. The fluoroplastic foaming extrusion production system according to claim 1, characterized in that, In the integrated foaming extruder unit, the No. 1 inclined auxiliary extruder (13) and the No. 2 inclined auxiliary extruder (14) are locked and fixed after independent fine-tuning relative to the foaming head (5) in six degrees of freedom: up and down, front and back, left and right linear directions, and rotation angles around three coordinate axes, through a multi-degree-of-freedom mechanical connection structure.

6. The fluoroplastic foaming extrusion production system according to claim 1, characterized in that, The extrusion screws of the main extruder (12), the first inclined auxiliary extruder (13), and the second inclined auxiliary extruder (14) are all driven by motors; the barrels of the main extruder (12), the first inclined auxiliary extruder (13), and the second inclined auxiliary extruder (14) are provided with a sliding support structure in the axial direction that allows free expansion and movement after being heated.

7. The fluoroplastic foaming extrusion production system according to claim 1, characterized in that, The reel take-up machine (32) is equipped with a wire-catching hook device for automatically capturing and guiding the cable at the start of take-up.

8. The fluoroplastic foaming extrusion production system according to claim 1, characterized in that, The gas supply and detection system (15) is a nitrogen pressurization and flow detection system; the control module (30) receives the measurement signals from the underwater capacitance meter (21) and the downstream biaxial diameter measuring instrument (16), and achieves closed-loop control of the foaming degree and outer diameter of the insulation layer by adjusting the nitrogen flow rate and the screw speed of the extruder.

9. The fluoroplastic foaming extrusion production system according to claim 1, characterized in that, The analysis and prediction module (29) performs time-domain-frequency domain transformation analysis on the data detected by the four-axis eccentricity meter (24) and the three-axis concave-convexity meter (27) to identify and predict the periodic quality fluctuation trend in the production process.

10. A method of using the fluoroplastic foaming extrusion production system as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: The conductor is mounted on the moving plate wire feeding machine (1) and fed out in a moving plate manner, so that the conductor release direction is parallel to the center line of the production line; after being monitored by the front-end biaxial diameter measuring instrument (2), it enters the oven preheater (3) for preheating; S2: The preheated conductor is pulled into the central conductor channel of the foaming head (5) by the front traction machine (6); S3: Fluoroplastic material is fed into the hopper of each extruder through a vacuum filling machine (4); at the same time, nitrogen is injected into the flow channel of the foaming head (5) through a nitrogen injection needle via a gas supply and detection system (15); S4: The main unit mixes the gas and molten fluoroplastic, and then extrudes it together with the rubber material from the auxiliary machine in the foaming head (5) to cover the surface of the conductor and form a foamed insulation layer. S5: After the insulation core is shaped by the vacuum device (7), it enters the movable warm water tank (17) and the fixed warm water tank (20) for graded cooling, and the insulation capacitance is measured online by the underwater capacitance meter (21); then it is cooled and dried by the spray water tank and the blower. S6: The dried wire core is sequentially inspected by a four-axis eccentricity tester (24), a rear traction machine (25), an EDM machine (26), and a three-axis concave-convexity tester (27). The data is collected by the data display and processing device (28) and then analyzed and optimized by the analysis and prediction module (29) and the control module (30). S7: The cable is finally cooled and dried by the No. 2 spray water tank (31). The No. 2 spray water tank (31) is equipped with a water capacitance meter (21) to monitor the capacitance of the cable. Finally, the cable is wound into a coil by the moving coil take-up machine (32).

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