A drip irrigation tape anti-blocking performance strengthening production system and method

Abstract

The present application relates to the technical field of plastic extrusion molding, and discloses a drip irrigation belt anti-blocking performance strengthening production system and method, which comprises the following steps: providing a steady-state molten polymer base flow, and superimposing a periodic pulse flow on the base flow; and after the action of each cycle of the pulse flow, analyzing the real-time rheological properties of the molten polymer according to the pressure decay curve monitored by a pressure sensor, and then adjusting the control parameters of the subsequent pulse flow. The present application establishes a dynamic micro-forging molding mode, thereby avoiding the molding defects of the micro-channel of the drip head inside the drip irrigation belt. The process action and process sensing are integrated in the present application, so that the production system can actively adapt to the fluctuations in the physical properties of the raw materials, and finally the product obtains the anti-blocking property due to its internal structural integrity.

Description

Technical Field

[0001] This invention relates to a production system and method for enhancing the anti-clogging performance of drip irrigation tape, belonging to the field of plastic extrusion molding technology. Background Technology

[0002] In the production of drip irrigation tape, to ensure high production efficiency and the stability of the product's main dimensions, the industry generally adopts steady-state continuous extrusion molding. This method controls process parameters to allow the polymer melt to flow through the mold in a continuous and stable laminar flow state and complete the shaping. This production method is widely used because of its mature and easy-to-control process. However, the core function of drip irrigation tape products relies on the complex flow channel geometry of its internal drippers to achieve uniform drip irrigation. These channels are designed as a labyrinthine structure with many sharp turns and narrow cross sections. The purpose is to actively induce turbulence when water flows through, so as to achieve self-cleaning and avoid clogging.

[0003] Therefore, in the production practice of drip irrigation tape, there is a mismatch in process requirements. The industry has always adopted a laminar flow process that pursues smooth and orderly overall melt flow to reproduce a complex geometric structure that aims to induce disordered fluid flow in subsequent applications. When the production process uses recycled materials with unstable flowability for the sake of economy, or carries out high-speed production with thin walls, the physical effects of the above mismatch become more and more significant. Due to its own viscosity, the melt in the laminar flow state is difficult to achieve full filling in a very short time when it flows at high speed through the sharp turns or narrow areas of the dripper channel in the mold. This cannot be solved by simply adjusting the process parameters, because simply increasing the melt temperature or extrusion pressure can enhance the filling capacity to a certain extent, but it will also cause new process problems such as material degradation or product size loss.

[0004] The molding limitations inherent in the physical principles of steady-state continuous extrusion inevitably leave molding defects on the inner wall of the dripper channel that are difficult to detect through conventional visual inspection. Specifically, existing technologies have the following shortcomings: 1. Low molding fidelity of the channel structure; the geometry of its inner wall deviates from the design, affecting its intended hydraulic properties from the outset; 2. Residual stress forms inside the product, which easily leads to fatigue cracking of the material during long-term use, reducing product reliability; 3. Residual geometric defects provide a physical basis for the deposition of water impurities and the adhesion of biofilms during subsequent use, directly causing blockages. Therefore, the technical problem to be solved by this invention is how to introduce a new melt filling and molding mechanism without changing the main flow of the continuous extrusion process to overcome the inherent defects of steady-state laminar flow in reproducing complex channel structures, thereby improving the internal structural molding quality of drip irrigation tape products. Summary of the Invention

[0005] This invention provides a production system and method for enhancing the anti-clogging performance of drip irrigation tape. Its main purpose is to solve the problem of how to overcome the inherent defects of steady-state laminar flow and improve the structural forming quality of complex internal flow channels in products by introducing a new melt filling and forming mechanism in continuous extrusion processes.

[0006] To achieve the above objectives, the present invention provides a drip irrigation tape anti-clogging performance enhancement production system, the system comprising:

[0007] The extruder is configured to generate molten polymer and output it as a steady-state base flow at a reference flow rate.

[0008] The extrusion die, connected to the extruder, is configured to receive the substrate flow and form the drip tape and the microchannels of the drippers inside the drip tape;

[0009] A flow modulator is installed between the extruder and the extrusion die;

[0010] A pressure sensor is configured to monitor the pressure signal at the extrusion die inlet;

[0011] The controller, connected to a flow modulator and a pressure sensor, is configured to: control the flow modulator to superimpose periodic pulsed flows on the base flow to hydraulically forge-fill the molten polymer in the extrusion die in an asymmetric flow field mode; after each cycle of the pulsed flow, acquire the pressure decay curve from the pressure sensor as the pressure falls back from the peak, and extract one or more characteristic parameters characterizing the real-time rheological properties of the molten polymer from the decay curve; and determine and adjust one or more control parameters for the pulsed flow in the next cycle based on the characteristic parameters.

[0012] Preferably, the controller is further configured to control the waveform of the pulse flow generated by the flow modulator to include three phases occurring sequentially in each cycle: an impulsive injection phase with a steep flow rise edge to reach an instantaneous flow peak; a tight holding phase with a flow value below the peak but above a reference value; and an orderly release phase with the flow rate gradually decreasing from the holding phase to the reference value at a controlled slope.

[0013] Preferably, when executing step c, the controller is configured to: calculate the deviation between the characteristic parameter and the preset target value; and adjust the amplitude of the pulse stream in the next cycle according to the value and sign of the deviation.

[0014] Preferably, the system further includes: a data recording unit connected to the controller, configured to record a continuous history of changes in the control parameters adjusted by the controller in step c over the entire length of the produced drip irrigation tape; and a data mapping unit configured to correlate the continuous history of changes with the traction speed data of the drip irrigation tape to generate a dataset characterizing the uniformity of the longitudinal forming quality of the drip irrigation tape.

[0015] Preferably, the controller is further configured to lock the frequency of the pulse flow with the traction speed of the drip irrigation tape to form an internal structural reinforcement zone with a predetermined spatial period on the longitudinal axis of the drip irrigation tape.

[0016] Preferably, when the controller performs step b, the characteristic parameters characterizing the real-time rheological properties of the molten polymer include at least one of the pressure decay time constant and pressure overshoot determined from the decay curve.

[0017] Preferably, the controller is configured to control the flow rate of the base flow to be between 80% and 95% of the total flow rate of the base flow and the pulse flow in one cycle.

[0018] Preferably, the dataset is constructed as a digital archive that associates the coordinates of each length of the drip irrigation tape with the corresponding values ​​of one or more control parameters. The digital archive is used for quality traceability of the drip irrigation tape.

[0019] Preferably, the flow modulator includes a servo motor and a plunger pump or precision regulating valve driven by the servo motor.

[0020] A method for enhancing the anti-clogging performance of drip irrigation tape, the method comprising the following steps:

[0021] Step a, provide a steady-state molten polymer base flow at a reference flow rate and guide the base flow into an extrusion die for forming the drip tape and its internal dripper microchannels;

[0022] Step b: Periodic pulsed flow is superimposed on the base flow to hydraulically forge-fill the molten polymer in the extrusion die in an asymmetric flow field mode.

[0023] Step c: After each cycle of the pulse flow ends, monitor the attenuation curve of the pressure at the extrusion die inlet from the peak, and extract one or more characteristic parameters characterizing the real-time rheological properties of the molten polymer from the attenuation curve.

[0024] Step d, and based on the characteristic parameters, determine and adjust one or more control parameters of the pulse flow for the next cycle.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. A novel plastic molding process was established by providing a continuous molten polymer base flow and superimposing a discontinuous periodic pulsed flow on it. The base flow is responsible for maintaining the continuity of the production process and the stability of the product's main dimensions, while the pulsed flow acts on the molding process of the dripper's microchannels in a hydraulic forging-like filling behavior. This mechanism, which divides and coordinates the continuous extrusion and dynamic forging processes in terms of time and function, transforms the molding process of polymer melt in complex mold cavities from the traditional passive filling to active densification and reshaping. This avoids molding collapse or internal stress concentration caused by uneven melt flow at channel corners or narrow cross sections. The resulting drip irrigation tape products achieve higher molding fidelity and structural integrity on the inner surface of the dripper's microchannels.

[0027] 2. Based on the above working method, the pressure response signal generated during and after the application of the pulse flow is used to analyze the real-time rheological characteristics of the molten polymer, and the control parameters of subsequent pulse flows are adaptively adjusted according to these characteristics. In this mechanism, while each forging pulse completes its active shaping task on the melt, the pressure decay process generated after it acts on the melt system also becomes a real-time detection of the internal state of the melt. This closed-loop tuning method that integrates process action and process perception enables the production system to actively adapt to the fluctuations in the physical properties of raw materials caused by factors such as the use of recycled materials, thereby reducing the homogeneity requirements of the raw materials in the entire manufacturing process and improving the stability of the process.

[0028] 3. This method further records the continuous change history of pulse flow control parameters throughout the entire production process and correlates it with the length and position of the drip irrigation tape to generate a dataset characterizing the longitudinal quality uniformity of the drip irrigation tape. Since the change history of control parameters is a direct reflection of the production system's adaptive adjustment to cope with real-time fluctuations in raw materials, this dataset becomes the real data of the product manufacturing process. It transforms the process control information that was originally discarded after production into an inherent digital archive that accompanies the product itself. This makes the quality of each roll of drip irrigation tape no longer a macroscopic assessment based on random sampling, but an intrinsic attribute that can be known and traced point by point along its length. At the same time, by specifically setting the waveform of the pulse flow to three stages of impact injection, dense holding, and orderly slow release, the filling and solidification process of the melt in the micro-channel is more precisely controlled. Among them, the impact injection stage uses a steep pressure rise to quickly deliver the melt to the fine part of the mold cavity. The subsequent dense holding stage eliminates the small defects inside the material and releases stress under a continuous pressure. The final orderly slow release stage avoids melt backflow that may be caused by a sudden drop in pressure. Attached Figure Description

[0029] Figure 1This is a flowchart of the closed-loop control based on real-time rheological sensing of the present invention.

[0030] Figure 2 This is a graph showing the adaptive tuning relationship between the pressure decay time constant and the pulse amplitude of the present invention.

[0031] Figure 3 This is a schematic diagram of the integrated hardware and information architecture of the production system of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] This invention provides a production system and method for enhancing the anti-clogging performance of drip irrigation tape. The system includes an extruder, an extrusion die, a flow modulator, a pressure sensor, and a controller positioned between the extruder and the extrusion die. The controller is connected to the flow modulator and the pressure sensor to coordinate and control the entire production process. The system's working principle involves decomposing the traditional steady-state continuous extrusion process into a superposition of a continuous molten polymer base flow used to maintain the stability of the product's main structure and a periodic pulse flow used to dynamically shape the microchannels inside the dripper. The pressure response signal generated after the pulse action is used to analyze the real-time rheological characteristics of the molten polymer online, thereby achieving closed-loop adaptive adjustment of the subsequent pulse flow control parameters, improving the shaping fidelity and structural integrity of the microchannels inside the product. In a specific application scenario, this system is used to address the difficulty in ensuring the dripper's flow channel stability due to melt viscosity fluctuations when using recycled polyethylene with unstable melt flow index for high-speed production of thin-walled drip irrigation tape. Technical issues related to molding quality; to address this challenge, the controller is configured to execute a molding method that combines continuous production with dynamic forging. Specifically, the controller first instructs the extruder to generate a stream of molten polymer with a constant flow rate as a steady-state base stream. The flow rate of this base stream is set within the range of 80% to 95% of the total flow rate throughout the production cycle. When the base stream percentage is below 80%, it may be insufficient to maintain the stable shape of the thin-walled tube blank during the non-operational period of the pulse stream. When it is above 95%, the relative energy percentage of subsequent pulse streams is too low to achieve filling. Therefore, the function of this base stream is to form the main tube wall of the drip irrigation tape, ensuring the continuity and stability of macroscopic dimensions. Above this base stream, the controller periodically superimposes a pulse stream with an instantaneous flow rate much higher than the reference value by precisely controlling the flow modulator. This pulse stream fills the tube using a high-energy hydraulic forging method, and its pressure wave fills the microscopic corners of the dripper channel cavity with melt to avoid molding defects caused by insufficient material fluidity.

[0034] To address the issue of fluctuations in the physical properties of raw materials, the system establishes a closed-loop tuning mechanism. Given that the real-time rheological properties of the molten polymer are a direct factor affecting molding quality, yet difficult to measure directly online, the system employs the following procedure for online characterization and utilization: At the end of each pulse flow cycle, i.e., after the pressure reaches its peak, the controller obtains the pressure decay curve at the mold inlet from the pressure sensor, showing the pressure falling back from the peak. From this decay curve, one or more characteristic parameters characterizing the real-time rheological properties of the molten polymer are extracted. In a preferred embodiment, the characteristic parameters include at least one of a pressure decay time constant and a pressure overshoot. The pressure decay time constant reflects the current effective viscosity of the melt; the higher the viscosity, the slower the pressure decay and the larger the time constant. Based on the extracted characteristic parameters, the controller determines and adjusts one or more control parameters for the pulse flow in the next cycle. For example, the system presets a target pressure decay time constant. When the controller executes step c, it calculates the measured time constant for the current cycle. Deviation from the preset target value And based on this deviation, the amplitude of the pulse current in the next cycle is... Adjustments are made, and a specific adjustment logic can be expressed as follows: ,in, This is the pulse current amplitude for the next cycle; This represents the pulse current amplitude for the current cycle. This is a control coefficient calibrated through offline experiments. It should be noted that if the measured time constant is greater than the target value, it indicates that the melt viscosity has increased. The controller will then increase the amplitude of the pulse flow in the next cycle according to the above logic, so as to compensate for the increased flow resistance with stronger forging force. Through this cycle-by-cycle adaptive tuning, the entire manufacturing process can actively adapt to the fluctuation of raw materials and improve the stability of the process.

[0035] To further refine the control of the filling and solidification process of the melt within the microchannels, the controller is further configured to control the waveform of the pulsed flow generated by the flow modulator to include three sequentially occurring stages in each cycle. The first stage is the impact injection stage, characterized by a steep flow rise edge to reach an instantaneous flow peak in a short time, forcibly delivering the material to the fine details of the mold cavity. The second stage is the compaction and pressure holding stage, where, after reaching the peak, the flow rate drops to a plateau below the peak but above the reference value and is maintained for a short period, allowing the impact-injected material to fully compact under pressure. The first stage densifies and releases molding stress; the third stage is the orderly slow-release stage. After the pressure holding plateau, the flow rate returns to the baseline value with a controlled and relatively gentle downward slope to prevent melt backflow or flow turbulence that may be caused by a sudden drop in pressure. The orderly connection of these three stages integrates part of the logic of the injection molding process into continuous extrusion production. In addition, the system also includes a data recording unit and a data mapping unit. During the production process, the controller's continuous adaptive adjustment of the pulse flow control parameters to cope with raw material fluctuations is itself a true record of the molding process. Therefore, the data recording unit is configured to record the entire process of producing drip irrigation tape. Over a long range, the controller adjusts control parameters to form a continuous history of changes. The data mapping unit then correlates this continuous history with the traction speed data of the drip irrigation tape to generate a dataset characterizing the uniformity of the longitudinal forming quality of the drip irrigation tape. This dataset is constructed as a digital archive that associates each length coordinate point of the drip irrigation tape with the corresponding values ​​of one or more control parameters. For example, an archive recording the pulse amplitude adjustment for each meter along the length of the drip irrigation tape; a section with a consistently high amplitude adjustment indicates that the raw material used in that section has poor flowability during production. In this way, the original process control information... The information is transformed into a quality traceability file accompanying the physical product itself; in one embodiment, the flow modulator includes a servo motor and a plunger pump or precision regulating valve driven by the servo motor, which can provide high dynamic and high-precision response and control of the flow; at the same time, the controller is further configured to lock the frequency of the pulse flow with the traction speed of the drip irrigation tape. For example, if the traction speed of the drip irrigation tape is 120 meters / minute, or 2 meters / second, and the design requires a dripper to be installed every 0.2 meters, the controller will set the pulse frequency to 10 Hz to form an internal structural reinforcement zone at the position of each dripper on the longitudinal axis of the drip irrigation tape.

[0036] Example 1: In a high-speed continuous extrusion production of thin-walled drip irrigation tape with a wall thickness of 0.15 mm using recycled polyethylene material containing impurities and with fluctuating melt index between batches, the production line faces a technical conflict between maintaining high traction speed and ensuring the fidelity of the microchannel forming of the drippers. Traditional steady-state extrusion methods, to adapt to high-speed traction, require maintaining the melt within a low viscosity working window, but this increases the risk of dimensional runaway due to raw material fluctuations. Reducing the extrusion temperature or speed to ensure molding quality does not meet the economic requirements of production. When a batch of recycled material on the production line experiences a momentary increase in melt viscosity due to a decrease in melt index, the controller monitors the pressure decay time constant after the previous forging pulse ends via a pressure sensor. An extension occurred, and the controller immediately executed the closed-loop tuning procedure to correct this deviation. The preset control logic is input for calculation to determine the pulse flow control parameters for the next cycle; In the formula, The pulse current amplitude for the next cycle. The pulse current amplitude for the current cycle. This is a control coefficient calibrated through offline experiments. The deviation between the measured pressure decay time constant and the preset target value; the adjustment command output by the closed-loop tuning mechanism is used as the input for dynamic reconstruction of the subsequent pulse flow waveform, and the controller, based on... While increasing the pulse amplitude, the rising edge slope of the impact injection stage is further set to be steeper, and the duration of the densification and pressure holding stage is appropriately extended, so as to use the increased impact force to overcome the flow resistance of the high-viscosity melt and provide more sufficient densification and stress release time for the melt with poor flowability.

[0037] To verify the impact of fluctuations in the physical properties of raw materials on the forming quality of drippers inside the drip irrigation tape, a set of comparative experiments was conducted. The experimental platform used a single-screw extruder with a screw diameter of 45 mm and a length-to-diameter ratio of 33:1. Its outlet was connected to the production system, and the pressure sensor in the system had a sampling rate of 1 kHz and an accuracy of 0.1% FS. The experiment set up a control group and an experimental group of the present invention. The control group adopted a steady-state continuous extrusion process, while the experimental group of the present invention adopted an asymmetric flow field forming method with closed-loop tuning function enabled. The experimental materials included material A and material B. Material A was a brand new polyethylene material with a melt index stable at 2.1 g / 10 min, and material B was a material with a melt index of 1.7-2.5 g / min. The experiment involved recycled polyethylene material fluctuating within a 10-minute range. The experiment was divided into three groups: Control Group 1 used material A, while Control Group 2 and the sample group of this invention both used material B. The extruder temperature, screw speed, and product traction speed were set to the same values ​​for each group. The evaluation method involved randomly sampling 100 drippers from each group's drip tape production and measuring the dimensions of the narrowest flow channel cross-section using a scanning electron microscope. The percentage of samples with a critical dimension deviation of less than 2% was calculated as the micro-flow channel forming fidelity. During the experiment, the controller of the sample group of this invention recorded some process parameters. Table 1 excerpts the adaptive adjustment data of the system for five consecutive forging cycles when the melt viscosity increased due to batch switching of material B.

[0038] Table 1: Example table of adaptive tuning process data for the sample group of the present invention.

[0039]

[0040] Table 1 shows the target pressure decay time constant of the system. The set value is 150ms. In the (n+1)th cycle, it was detected that... The delay is caused by raw material switching, and the closed-loop tuning mechanism correspondingly increases the pulse current amplitude in subsequent cycles. To compensate for the increased flow resistance; the statistical results of molding fidelity of the three groups of tests are shown in Table 2.

[0041] Table 2: Comparison of model fidelity results for each experimental group.

[0042]

[0043] Comparing the data in Table 2, the control group 2, which uses a steady-state continuous extrusion process, has a molding fidelity of 81.5% when using material B with fluctuating performance, which is lower than the 99.2% of the control group 1, which uses stable material A. The sample group using the method of this invention has a microchannel molding fidelity of 98.7% when using the same material B, which is close to the benchmark control group 1. The test results show that the technical solution can maintain the molding stability of the internal microstructure of the drip irrigation tape product when processing raw materials with fluctuating physical properties.

[0044] To further verify the advantages of this invention over the prior art from the dual perspectives of process stability and production economy, the following comparative example 1 is added.

[0045] Comparative Example 1: This comparative example aims to verify the actual impact on the final product molding quality, production process stability, and economy when processing recycled polyethylene B material with fluctuating physical properties under the same conditions as in Example 2, if the core technical solution of this invention is missing, namely, the lack of a closed-loop pulse tuning mechanism based on real-time rheological sensing, and only the conventional steady-state continuous extrusion process described in the background section is used. To ensure the fairness of the comparison, the basic conditions used in this comparative example, such as the test platform, test material (B material, melt index fluctuating in the range of 1.7-2.5 g / 10 min), extruder initial temperature setting, screw initial speed, and product initial traction speed (120 m / min), are all consistent with the sample group of this invention in Example 2 at the character level. The essential difference is that the flow modulator and the entire closed-loop tuning and control software in this comparative example are inactive, and the production system operates entirely in the traditional steady-state continuous extrusion mode.

[0046] After the experiment began, the system initially maintained relatively stable production. However, after approximately 15 minutes of operation, the introduction of another batch of raw material into material B caused a change in its melt index, resulting in a significant increase in melt viscosity. Pressure sensors revealed an irregular increase in pressure at the extrusion die inlet, lasting for over 30 seconds and reaching a 15% amplitude. To prevent large-scale collapse or even flow interruption of the dripper's microchannels due to decreased melt flowability and insufficient filling capacity, which could lead to the scrapping of the entire product line, the on-site operators were forced to intervene according to standard operating procedures, reducing the production line's traction speed from 1... The speed was reduced from 20 m / min to 95 m / min to prolong the filling time of the melt in the mold. Despite the speed reduction measures, the stability of the production process was still not ideal, and the pressure of the die head still showed a wide range of fluctuations of ±10%. After running for another 30 minutes under the reduced speed conditions, the drip irrigation tape produced in this stage was sampled and evaluated. The evaluation method was completely consistent with that in Example 2, that is, 100 drip heads were randomly sampled and measured and statistically analyzed using a scanning electron microscope. At the same time, the production efficiency and product scrap rate of the entire comparative test process were recorded. The specific test results and observed phenomena are summarized in Table 3.

[0047] Table 3: Statistical table of experimental process and results for Comparative Example 1.

[0048]

[0049] The results of Comparative Example 1 show that when processing recycled materials with unstable physical properties, the traditional steady-state continuous extrusion process, lacking the ability to perceive and compensate for real-time fluctuations in raw materials, cannot resolve the inherent contradiction between high-speed production and high-fidelity molding. When encountering raw material fluctuations, it not only fails to maintain the microscopic molding quality of the product (molding fidelity is only 81.5%), but also causes significant process consequences: to ensure the most basic product usability, production efficiency has to be sacrificed (speed reduction of more than 20%), and even so, a scrap rate as high as 18.5% still occurs. This result objectively confirms that the lack of a closed-loop tuning method that integrates process action and process perception, as proposed in this invention, is the reason why the existing technology has poor process stability, low product quality consistency, and poor production economy when dealing with uncertain raw materials.

[0050] Example 2: This example combines Figures 1 to 3 This document describes a production system and method for enhancing the anti-clogging performance of drip irrigation tape, such as... Figure 1 As shown, the extrusion die and pressure sensor serve as the physical basis, used to monitor the die pressure and output a real-time pressure signal. This signal is used to generate a pressure decay curve. Based on this curve, the rheological characteristic module can obtain real-time rheological characteristic parameters characterizing the melt state. These parameters, along with the target pressure decay time constant from the A1 target process parameter database, are input into the calculation control deviation module. The output control parameter deviation is then used to dynamically adjust the pulse parameters to generate the pulse parameters for the next cycle and create a history of control parameter changes, which is stored in the A2 production process digital archive. Finally, the adjusted parameters, in the form of adaptive pulse control commands, drive the flow modulator to generate a composite pulse waveform, thereby precisely influencing the melt forming process in the next cycle.

[0051] like Figure 2 As shown, the horizontal axis represents the forging cycle number, continuously from n to n+7; the left vertical axis represents the time constant in milliseconds (ms); and the right vertical axis represents the relative unit of pulse amplitude. The figure contains three curves. The target value of 150ms serves as a constant reference baseline. The pressure decay time constant curve shows the dynamic process of the measured process variable deviating from the target value due to external disturbances and subsequently returning to the target value. The pulse amplitude adjustment curve visually reflects the adaptive adjustment of the controller output to suppress the above deviations, which closely follows the timing and is negatively correlated in magnitude, presenting the system's regulatory behavior in response to process fluctuations.

[0052] like Figure 3As shown, the core of this architecture is an industrial control host, which runs closed-loop tuning and control software, data logging services, and process safety monitoring logic. At the physical layer, the host senses the process status by receiving sensor signals from the pressure sensor on the extrusion die and sends control commands to the flow modulator located between the extruder and the extrusion die via the fieldbus, thereby precisely modulating the material flow from the extruder. The final product is processed by the traction and winding unit. At the information layer, the host communicates with the upper-level operator terminal HMI and its human-machine interface, as well as the data server for storing the quality traceability database, via industrial Ethernet, together forming a complete manufacturing system integrating process control, data logging, and quality traceability functions.

[0053] Example 3: This example describes an engineering procedure used to calibrate key control parameters of a closed-loop tuning mechanism during production task switching. When the production system needs to switch to a new recycled polyethylene material C containing different component proportions, in order to ensure that the system can stably control the rheological characteristics of this material C after production starts, the target pressure decay time constant needs to be calibrated before formal production. With control coefficient Perform offline calibration; the first step in the calibration procedure is to determine the target pressure decay time constant corresponding to the C material. The operators used this C material to conduct short-term trial production at a low traction speed, fine-tuning the extrusion temperature and screw speed until the produced drip irrigation tape samples were inspected and the internal flow channel forming quality of the drippers met the preset standards. Under this stable operating condition, the system continuously collected pressure decay curve data for 100 forging cycles and executed an algorithm on each curve to extract the pressure decay time constant. The algorithm's steps are as follows: the difference between the peak pressure and the steady-state baseflow pressure is defined as the peak pressure increment. Then, the pressure value is calculated from the peak value down to the base flow pressure plus... The time elapsed is used as the pressure decay time constant. The measured values ​​were then used to calculate the results for these 100 cycles. The arithmetic mean of the values ​​is 185.0 ms, and this value is set as the target pressure decay time constant that the controller needs to maintain in subsequent production. .

[0054] The second step in the calibration procedure is to determine the control factors. The value of; after completing After the settings are configured, the operator introduces a step disturbance into the system, instantaneously increasing the extruder screw speed by 2% to simulate an increase in melt extrusion volume. The controller will detect this. Started to deviate from the set target value The operator enters the control coefficients into the controller's engineering parameter interface. The values ​​were set to three groups of values: 0.005, 0.010, and 0.020, and the results were observed after applying a disturbance to the system under each set of values. After considering the number of forging cycles and the stability of the convergence process, a control coefficient value of 0.010 was finally selected as the setpoint for the production conditions of material C, which enables the system to respond quickly and converge without overshoot. By executing this calibration procedure, initial control parameters matching the material characteristics were provided for the closed-loop tuning system.

[0055] Example 4: This example describes a procedure for online quality grading and process anomaly monitoring using datasets during continuous production. In a long-duration continuous production task, the controller uses a data mapping unit to map the pulse current amplitude generated by closed-loop tuning throughout the entire production range. The continuous variation history of the drip irrigation tape is correlated in real time with the length coordinates of the drip irrigation tape to generate a dataset characterizing the uniformity of the longitudinal forming quality of the drip irrigation tape. To transform this dataset into a traceable grading index, the controller is configured to execute a segmented quality assessment algorithm, which calculates the amplitude of all pulse flows within a 10-meter segment. The arithmetic mean and standard deviation of the values ​​are then compared with the benchmark values ​​determined in the calibration procedure of Example 3. Based on whether the deviation exceeds a preset threshold, the 10-meter-long drip irrigation tape segment is rated as a different quality level, and the level information is written into the final digital file.

[0056] During the production process, if a partial blockage occurs inside the extrusion die 2 due to the intrusion of external impurities, the die head pressure will rise continuously, deviating from normal raw material fluctuations. To address this situation, the controller also executes a parallel process safety monitoring logic. This logic continuously compares the real-time die head inlet pressure measured by the pressure sensor with a preset absolute safety threshold that is 180% of the normal operating pressure. Once the pressure value exceeds this safety threshold and remains above it for more than 3 seconds, the controller determines that the system has entered an abnormal process state and automatically executes a safety response procedure. This procedure takes precedence over the closed-loop tuning mechanism. Its steps include immediately stopping the pulse output of the flow modulator, reducing the screw speed of the extruder to the minimum speed, and triggering an audible and visual alarm to prompt the operator to intervene.

[0057] Example 5: This example illustrates an offline optimization procedure for determining key process parameters of a three-stage composite waveform. When producing a drip irrigation tape product with a novel and complex internal flow channel structure, to find a parameter combination that balances the performance indicators of micro-forming fidelity and residual internal stress, the duration of the compaction and pressure holding stage needs to be determined before mass production. The slope of pressure decrease during the orderly slow-release phase Systematic experiments were conducted; this calibration procedure, under the condition that parameters such as fixed base flow rate and pulse peak pressure remain unchanged, selected three levels of tight pressure holding stage durations. The time intervals were 50ms, 100ms, and 150ms, respectively, and the pressure drop slopes of the ordered sustained-release phases were selected at these three levels. Nine sets of process parameters were combined for short-time production, each with three decreasing preset slope values. For the samples produced by each parameter combination, two key performance indicators were tested: the dimensional deviation at the narrowest point of the dripper's internal flow channel, measured using a scanning electron microscope; and the residual internal stress level of the sample, characterized by birefringence observed using a cross-polarized light microscope. Based on the data from the nine sets of experiments, the duration of the compaction and pressure holding stage was determined. At 50ms, the product's molding fidelity does not meet the preset engineering requirements, while the pressure drop slope during the ordered release phase... When the slope value is set to the highest level, the residual internal stress level of the product exceeds the acceptable standard; based on this experimental data, the tight pressure holding time is selected. 100ms, ordered sustained-release slope A combination of parameters with a moderate slope is used as the manufacturing process setting for this specific product, and this set of parameters is loaded into the controller.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A drip irrigation tape anti-clogging performance enhancement production system, characterized in that, The system comprises: an extruder configured to generate and output a molten polymer in a steady-state base flow with a flow rate at a reference value; an extrusion die connected to the extruder and configured to receive the base flow and shape the drip irrigation tape and the micro-flow channels of the emitters inside the drip irrigation tape; a flow modulator disposed between the extruder and the extrusion die; a pressure sensor configured to monitor a pressure signal at an inlet of the extrusion die; a controller connected to the flow modulator and the pressure sensor, the controller being configured to: control the flow modulator to superimpose a periodic pulse flow on the base flow to perform a hydrodynamic forging filling of the molten polymer in the extrusion die in an asymmetric flow field pattern; obtain, from the pressure sensor, a decay curve of the pressure falling back from a peak value after each cycle of the pulse flow, and extract one or more characteristic parameters from the decay curve, the characteristic parameters being indicative of real-time rheological properties of the molten polymer; and determine and adjust one or more control parameters of the pulse flow of a next cycle according to the characteristic parameters; wherein the controller is further configured to control the pulse flow generated by the flow modulator to have a waveform in each cycle, the waveform comprising three phases occurring in sequence: a shock injection phase with a steep flow rising edge to reach a peak flow value; a compact pressure maintaining phase with a flow value lower than the peak value but higher than the reference value; and an orderly slow release phase with a flow controlled to gently decrease from the pressure maintaining phase to the reference value; wherein the characteristic parameters indicative of the real-time rheological properties of the molten polymer include at least one of a pressure decay time constant and a pressure overshoot determined from the decay curve; the controller is configured to control the flow rate of the base flow to be eighty percent to ninety-five percent of a total flow rate of the base flow and the pulse flow in a cycle.

2. The system according to claim 1, wherein, the controller is configured to: calculate a deviation between the characteristic parameters and a preset target value; and adjust an amplitude of the pulse flow of the next cycle according to a value and a sign of the deviation.

3. The system according to claim 1, wherein, The system further comprises: a data recording unit connected to the controller and configured to record a continuous change history of the control parameters adjusted by the controller in a full length range of the drip irrigation tape produced; and a data mapping unit configured to associate the continuous change history with traction speed data of the drip irrigation tape.

4. The system according to claim 1, wherein, The flow modulator comprises a servo motor and a plunger pump or a regulating valve driven by the servo motor.

5. A method for enhancing the anti-clogging performance of a drip irrigation tape, applied to the production system according to any one of claims 1-4, characterized in that, The method comprises the following steps: Step a, providing a steady-state molten polymer base flow with a flow rate at a reference value, and introducing the base flow into an extrusion die for shaping the drip irrigation tape and the micro-flow channels of the emitters inside the drip irrigation tape; Step b, superimposing a periodic pulse flow on the base flow to perform a hydrodynamic forging filling of the molten polymer in the extrusion die in an asymmetric flow field pattern; Step c, monitoring a decay curve of the pressure falling back from a peak value after each cycle of the pulse flow, and extracting one or more characteristic parameters from the decay curve, the characteristic parameters being indicative of real-time rheological properties of the molten polymer; Step d, determining and adjusting one or more control parameters of the pulse flow of a next cycle according to the characteristic parameters.

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