Dynamic temperature control methods, systems, and equipment for plastic film production.

Abstract

This invention provides a dynamic temperature control method, system, and equipment for plastic film extrusion, relating to the field of temperature control technology. The method includes: synchronously sampling multi-source temperatures from a plastic film extruder to obtain a synchronous time-series temperature data set; performing multi-scale thermal field coupling state characterization and modeling to obtain a thermal field coupling state matrix; performing time-series drift analysis to identify the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, forming a thermal field instability partitioning result; constructing a partitioned thermal response weight factor set; allocating collaborative temperature regulation parameters to generate temperature correction commands for multiple execution units; and performing closed-loop dynamic thermal field correction. This invention solves the technical problem that existing technologies typically control based only on single-point temperature deviations, lacking collaborative analysis of different parts of the plastic film extruder, leading to asynchronous thermal responses among temperature control units, and consequently, difficulty in maintaining a uniform and stable overall thermal field distribution.

Description

Technical Field

[0001] This invention relates to the field of temperature control technology, and more specifically to a dynamic temperature control method, system, and equipment for the preparation of plastic film using a plastic film machine. Background Technology

[0002] Plastic films are widely used in packaging, electronics, agriculture, and functional materials, and their production is typically accomplished through extrusion blow molding or cast extrusion processes. During the heating of the plastic melt in the barrel, the forming process in the die, and the cooling and solidification process, the temperature distribution directly affects the melt flow uniformity, stretching stability, and the final film thickness uniformity and mechanical properties. Therefore, achieving precise temperature control during the plastic film extrusion process is a crucial technical aspect for ensuring stable product quality.

[0003] Currently, plastic film extrusion equipment typically employs segmented temperature control to independently control the barrel heating zone and the die heating zone. Each temperature control unit primarily adjusts its temperature based on feedback from its corresponding measuring point. While this control method achieves basic temperature control, the complex heat conduction, diffusion, and convection heat transfer coupling between the barrel, die, and cooling system results in a distinctly dynamic and correlated overall thermal field. Existing technologies often rely solely on single-point temperature deviations, lacking comprehensive analysis of different components. This leads to asynchronous thermal responses among the temperature control units, making it difficult to maintain a uniform and stable overall thermal field distribution. Summary of the Invention

[0004] This application provides a dynamic temperature control method, system, and equipment for the preparation of plastic film machines, aiming to solve the technical problem that existing technologies usually control based only on single-point temperature deviations, lacking coordinated analysis of different parts of the plastic film machine, resulting in asynchronous thermal responses among temperature control units, and thus making it difficult to maintain a uniform and stable overall thermal field distribution.

[0005] The first aspect disclosed in this application provides a dynamic temperature control method for the preparation of plastic film using a plastic film extruder. The method includes: performing multi-source synchronous temperature sampling on the molding thermal field collaborative control unit of the plastic film extruder to obtain a synchronous time-series temperature data set; performing multi-scale thermal field coupling state characterization modeling based on the synchronous time-series temperature data set to obtain a thermal field coupling state matrix; performing time-series drift analysis on the thermal field coupling state matrix to identify the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, forming a thermal field instability partitioning result; constructing a temperature response priority mapping relationship based on the thermal field instability partitioning result, and constructing a partitioned thermal response weight factor set; allocating collaborative temperature adjustment parameters to the molding thermal field collaborative control unit according to the partitioned thermal response weight factor set, generating multi-execution unit temperature correction instructions; and using the multi-execution unit temperature correction instructions to perform closed-loop dynamic thermal field correction on the plastic film extrusion process.

[0006] The second aspect of this application discloses a dynamic temperature control system for the preparation of a plastic film machine. This system is used in the aforementioned dynamic temperature control method for the preparation of a plastic film machine. The system includes: a temperature sampling module for synchronously sampling multi-source temperatures of the molding thermal field collaborative control unit of a plastic film extruder to obtain a synchronous time-series temperature data set; a characterization and modeling module for performing multi-scale thermal field coupling state characterization and modeling based on the synchronous time-series temperature data set to obtain a thermal field coupling state matrix; a drift analysis module for performing time-series drift analysis on the thermal field coupling state matrix to identify the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, forming a thermal field instability partitioning result; a weighting factor construction module for constructing a temperature response priority mapping relationship based on the thermal field instability partitioning result, and constructing a partitioned thermal response weighting factor set; a parameter allocation module for allocating collaborative temperature adjustment parameters to the molding thermal field collaborative control unit according to the partitioned thermal response weighting factor set, generating multi-execution unit temperature correction instructions; and a thermal field correction module for performing closed-loop dynamic thermal field correction of the plastic film extrusion process using the multi-execution unit temperature correction instructions.

[0007] A third aspect of this application discloses an electronic device comprising: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the aforementioned dynamic temperature control method for preparing a plastic film machine.

[0008] One or more technical solutions provided in this application have at least the following beneficial effects: Multi-source synchronous temperature sampling achieves full-dimensional coverage of the extrusion molding thermal field, more realistically reflecting the spatial distribution differences and dynamic changes of the internal temperature field, thus improving the completeness and synchronicity of thermal state perception. Through multi-scale thermal field coupling state characterization, axial heat transfer, circumferential diffusion, and external convection disturbances are uniformly mapped into a thermal field coupling state matrix, achieving a unified expression of multi-heat source and multi-directional thermal effects, enhancing the systematicness and computability of the thermal field state description. Temporal drift analysis divides the thermal field into unstable regions, enabling spatial localization and type differentiation of thermal problems, transforming the control strategy from overall unified regulation to zoned differentiated control, improving control targeting. Furthermore, by constructing a temperature response... Priority mapping relationships and a set of partition weight factors enable different regions to obtain differentiated control weights based on thermal inertia, equilibrium requirements, and disturbance sensitivity, thereby achieving optimized allocation of control resources and improving the system's response efficiency and adjustment accuracy to key thermal instability areas. Temperature correction commands are generated through multi-execution unit collaborative parameter allocation, enabling the barrel heating, die heating, and cooling systems to form a collaborative closed-loop control relationship. This avoids control conflicts caused by independent adjustments of a single execution unit, improving the coordination and stability of the overall thermal field adjustment. Feedback-driven dynamic thermal field correction enables continuous optimized control of the film forming process, improving product uniformity and forming stability, and enhancing the system's adaptability to changes in operating conditions.

[0009] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the dynamic temperature control method for preparing plastic film using an embodiment of this application.

[0011] Figure 2 This is a graph showing the trend of temperature deviation in the thermal instability region of the dynamic temperature control method for preparing plastic film machine provided in the embodiments of this application.

[0012] Figure 3 This is a schematic diagram of the dynamic temperature control system for preparing plastic film in an embodiment of this application.

[0013] Figure 4 This is a schematic diagram of the structure of an exemplary computer device provided in an embodiment of this application.

[0014] Figure reference numerals: Temperature sampling module 10, Characterization modeling module 20, Drift analysis module 30, Weighting factor construction module 40, Parameter allocation module 50, Thermal field correction module 60, Processor 21, Memory 22, Input device 23, Output device 24. Detailed Implementation

[0015] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structure, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0016] Example 1, as Figure 1 As shown in the embodiments of this application, a dynamic temperature control method for preparing plastic film using a plastic film machine is provided, the method comprising: Multi-source temperature synchronous sampling was performed on the molding thermal field coordinated control unit of the plastic film extruder to obtain a synchronous time-series temperature data set.

[0017] Multi-source synchronous temperature acquisition is achieved by deploying multiple types of temperature sampling nodes in the segmented heating unit of the barrel, the annular heating unit of the die head, and the cooling air ring area of ​​the plastic film extruder. Specifically, segmented thermocouples are used along the barrel axis to acquire temperature sequences for each heating zone, reflecting the axial heat conduction state; annular array sensors are used in the circumferential direction of the die head to acquire angular discrete temperature distributions, characterizing circumferential uniformity; and airflow feedback temperature sampling points are set in the cooling area to capture the influence of external convective disturbances. Time alignment and resampling are performed on the three types of data using a unified time reference to eliminate sampling frequency differences and delay errors, ultimately forming a synchronous time-series temperature data set, providing a unified input basis for subsequent thermal field modeling.

[0018] Based on the synchronous time-series temperature data set, a multi-scale thermal field coupling state characterization model is performed to obtain the thermal field coupling state matrix.

[0019] A multi-scale thermal field coupling model is constructed based on a synchronous time-series temperature dataset. Specifically, an axial heat conduction gradient model for the barrel is established to describe the temperature progression and heat transfer efficiency along the axial direction; a circumferential heat diffusion uniformity model for the die head is established to characterize the circumferential temperature difference distribution and local non-uniformity; and a cooling disturbance convection model is established to characterize the dynamic influence of external airflow on local temperature. Based on this, a multivariate coupling mapping method is used to correlate and fuse the three models in both time and spatial dimensions, forming a unified thermal field coupling state matrix that comprehensively expresses the overall thermal state of the equipment and the mutual influence relationships between different regions.

[0020] A time-series drift analysis is performed on the thermal field coupling state matrix to identify the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, thus forming a thermal field instability partitioning result.

[0021] The thermal field coupling state matrix is ​​decomposed using a sliding time window to obtain thermal field sub-matrices for continuous time segments. The stability deviation of each sub-matrix relative to the baseline state is calculated to form a thermal offset coefficient sequence, where the thermal offset coefficient is used to measure the degree of deviation of the local thermal field over time. This sequence is compared and analyzed with a preset thermal uniformity threshold. When the deviation continuously exceeds the limit or shows a trend of drift, it is determined that there is abnormal thermal behavior in the corresponding area, thereby identifying the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, thus realizing the thermal field instability zoning.

[0022] Based on the results of the thermal field instability partitioning, a temperature response priority mapping relationship is constructed, and a set of partition thermal response weight factors is constructed.

[0023] Based on the results of thermal instability zoning, control response priorities for different regions are established. For the axial thermal hysteresis zone of the barrel, a thermal inertia response model is introduced to describe its temperature change hysteresis characteristics. For the circumferential temperature difference diffusion zone of the die head, a thermal equilibrium correction model is introduced to characterize the circumferential homogenization adjustment requirements. For the cooling disturbance sensitive zone, a disturbance suppression response model is introduced to assess the impact of external airflow on temperature stability. By comprehensively quantifying the response sensitivity, adjustment delay, and deviation suppression capability of each model, and matching the results with the thermal field stability offset, a temperature response priority mapping relationship and a set of zoning weight factors are formed.

[0024] Based on the set of partitioned thermal response weight factors, the forming thermal field collaborative control unit is allocated collaborative temperature adjustment parameters, and a multi-execution unit temperature correction command is generated.

[0025] Based on the set of partition weighting factors, collaborative parameters are allocated to different execution units. For the segmented heating unit of the barrel, the segment compensation amount is calculated according to the thermal inertia characteristics to correct the axial temperature lag; for the annular heating unit of the die head, weighted equilibrium parameters are calculated according to the circumferential uniformity model to improve the circumferential temperature difference; for the cooling air ring system, reverse temperature drift compensation parameters are calculated according to the disturbance intensity to offset the influence of airflow disturbance. Finally, the three types of parameters are fused according to the weighting factors to form a unified multi-execution unit temperature correction command, realizing collaborative adjustment between different control units.

[0026] The multi-execution unit temperature correction command is used to perform closed-loop dynamic thermal field correction in the plastic film extrusion process.

[0027] During the extrusion molding process, the transverse thickness distribution data of the film is continuously collected to reflect changes in molding quality. By establishing a mapping relationship between the thickness distribution and the thermal field coupling state matrix, the thermal-deformation deviation is calculated. This deviation characterizes the degree of mismatch between the temperature field and the material flow deformation. Based on this deviation, the temperature correction command is iteratively updated in real time to achieve closed-loop control. When the thickness fluctuation exceeds a preset threshold, the thermal field model and priority mapping relationship are reconstructed, thereby achieving adaptive dynamic optimization control.

[0028] Furthermore, multi-source temperature synchronous sampling is performed on the molding thermal field coordinated control unit of the plastic film extruder to obtain a synchronous time-series temperature data set, including: Multiple segmented thermocouple sampling nodes are arranged axially in the segmented heating unit of the barrel to periodically collect the output temperature of each heating segment, thereby obtaining the axial temperature distribution sequence of the barrel. A temperature sampling array is uniformly arranged circumferentially in the annular heating unit of the die head to perform angular discrete sampling of the heating area of ​​the die head, thereby obtaining the circumferential temperature distribution sequence of the die head. An airflow temperature feedback sampling unit is set in the air outlet area of ​​the cooling air ring to collect the temperature changes caused by the cooling airflow disturbance in real time, thereby obtaining the cooling disturbance temperature influence sequence. The axial temperature distribution sequence of the barrel, the circumferential temperature distribution sequence of the die head, and the cooling disturbance temperature influence sequence are time-reference aligned to form the synchronous time-series temperature data set.

[0029] Multiple thermocouple sampling nodes are arranged along the axial direction in the segmented heating unit of the barrel. Each node corresponds to a different heating zone, and the output temperature of each segment is periodically collected to form a temperature sequence data that changes over time. The axial temperature distribution sequence characterizes the heat conduction gradient and temperature progression law of the extruder along the material conveying direction, and can reflect the heating uniformity and axial thermal hysteresis phenomenon.

[0030] A temperature sampling array is uniformly arranged circumferentially in the annular heating unit of the mold head. The heating area of ​​the mold head is discretized according to angles, and the temperature at each angle position is collected synchronously to form a circumferential temperature distribution sequence. The circumferential discrete sampling describes the temperature difference distribution in the annular structure of the mold head, which is used to identify local uneven heating or boundary heat attenuation problems.

[0031] An airflow temperature feedback sampling unit is installed in the cooling air ring outlet area to monitor and record temperature changes under the action of cooling airflow in real time, forming a cooling disturbance temperature influence sequence. This sequence is used to characterize the dynamic disturbance intensity of the temperature field of the die head and melt region caused by external convection cooling, thereby reflecting the impact of the cooling system on the overall thermal stability.

[0032] The axial temperature distribution sequence of the barrel, the circumferential temperature distribution sequence of the die head, and the temperature influence sequence of cooling disturbance are aligned to a unified time base, including timestamp calibration, sampling frequency unification, and delay compensation, so that data from different sources can be compared on the same time scale. Finally, they are fused to form a synchronous time-series temperature data set, which is used as the input basis for subsequent thermal field coupling modeling.

[0033] Furthermore, based on the aforementioned synchronous time-series temperature data set, a multi-scale thermal field coupling state characterization model is performed to obtain a thermal field coupling state matrix, including: An axial heat conduction gradient model is constructed based on the axial temperature distribution sequence of the barrel; a circumferential heat diffusion uniformity model is constructed based on the circumferential temperature distribution sequence of the die head; an external convection disturbance model is constructed based on the cooling disturbance temperature influence sequence; the axial heat conduction gradient model, the circumferential heat diffusion uniformity model, and the external convection disturbance model are coupled and mapped to generate the thermal field coupling state matrix.

[0034] A heat conduction gradient model is established based on the axial temperature distribution sequence of the barrel. First, the barrel is divided into several heat dissipation zones along the axial direction. The temperature difference between adjacent zones is calculated using a first-order difference to obtain the axial temperature gradient field. Simultaneously, a time dimension is introduced, and the gradient changes at different sampling times are smoothed using a sliding window to eliminate instantaneous noise interference. Then, the gradient changes are normalized and corrected by combining the heating power input and the material flow direction to obtain the gradient coefficient reflecting the heat conduction efficiency. This model is used to characterize the continuity and hysteresis characteristics of heat transfer along the axial direction inside the barrel.

[0035] A uniformity model is constructed based on the circumferential temperature distribution sequence of the die head. First, the circumferential sampling points of the die head are mapped to polar coordinate space, and the deviation between the temperature at each angular position and the overall average temperature is calculated. Then, variance and range indices are introduced to form a characterization of the circumferential temperature dispersion. Simultaneously, a ring-shaped continuity analysis is performed on the temperature difference between adjacent angles to identify local hot or cold spots. Finally, a normalized uniformity index is used to express the degree of circumferential thermal diffusion uniformity of the die head.

[0036] A convective disturbance model is established based on the temperature influence sequence of cooling disturbances. By analyzing the fluctuation amplitude and frequency of temperature changes in the cooling air ring outlet area over time, a disturbance intensity function is constructed. Transient disturbance characteristics are extracted by combining the time derivative of temperature changes. Spatial influence weights are introduced to describe the attenuation degree of airflow influence on different forming areas. Finally, an external convective disturbance intensity model is formed to characterize the dynamic disturbance capability of the cooling system on the overall thermal field.

[0037] A multidimensional coupling mapping is performed on the axial heat conduction gradient model, the circumferential heat diffusion uniformity model, and the external convection disturbance model. First, the three models are normalized to a uniform scale to make them comparable in the same dimension space. Then, a three-dimensional state vector is constructed based on the time synchronization relationship, including axial gradient, circumferential uniformity, and disturbance intensity, and arranged in a matrix according to spatial location and time series. Finally, the interaction relationship of each dimension is fused through a coupling function to generate a thermal field coupling state matrix, which is used for the comprehensive expression of the overall thermal state and as input for subsequent analysis.

[0038] Furthermore, time-series drift analysis is performed on the thermal field coupling state matrix to identify the axial thermal hysteresis region of the barrel, the circumferential temperature difference diffusion region of the die head, and the cooling disturbance sensitive region, including: The thermal field coupling state matrix is ​​decomposed by a sliding time window to obtain multiple thermal field sub-matrices at different times; the stability deviation of the multiple thermal field sub-matrices at different times is calculated to generate a thermal offset coefficient sequence; the thermal offset coefficient sequence is compared and analyzed with a preset thermal uniformity threshold interval to obtain the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone.

[0039] The thermal field coupling state matrix is ​​decomposed using a sliding window process along the time dimension. This involves constructing continuous overlapping or non-overlapping time window intervals with a fixed time step, and extracting a corresponding subset of local thermal field data within each time window to form multiple time-series thermal field sub-matrices. The sliding time window is used to characterize the evolution of the thermal field over time, effectively preserving short-term fluctuations and stage-based changes, thereby decomposing the overall dynamic thermal field into a set of time-continuous local state representations.

[0040] For each thermal field submatrix, its stability deviation relative to the baseline thermal equilibrium state is calculated. Specifically, this is achieved by comparing the differences in temperature gradients, mean shifts, and fluctuation amplitudes at various spatial locations within the submatrix, forming a comprehensive stability index. A time-weighted factor is introduced to enhance sensitivity to persistent shifts. This results in the construction of a thermal shift coefficient sequence, which characterizes the degree to which the thermal field deviates from a uniform stable state within different time windows, thus providing a quantitative description of the evolution trend of thermal anomalies.

[0041] The thermal offset coefficient sequence is compared and analyzed with a preset thermal uniformity threshold range, where the threshold range is used to define the normal thermal field fluctuation range. When the offset coefficient of a certain spatial region continuously exceeds the upper limit of the threshold or shows a monotonically increasing trend, it is determined that there is a thermal stability imbalance in that region. Combining the spatial mapping relationship of axial, circumferential and cooling effects, the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head and the cooling disturbance sensitive zone are finally identified, realizing the spatial location and classification of thermal field instability.

[0042] Furthermore, based on the thermal field instability partitioning results, a temperature response priority mapping relationship is constructed, including: Based on the axial thermal hysteresis region of the barrel, a thermal inertial response model is constructed in conjunction with its axial temperature change inertial characteristics; based on the circumferential temperature difference diffusion region of the die head, a thermal equilibrium correction model is constructed in conjunction with its circumferential temperature diffusion gradient characteristics; based on the cooling disturbance sensitive region, a disturbance suppression response model is constructed in conjunction with its external airflow disturbance coupling characteristics; according to the sensitivity differences of the thermal inertial response model, thermal equilibrium correction model, and disturbance suppression response model to temperature deviation suppression capabilities, a matching calculation is performed with the stability offset results of the thermal field coupling state matrix to generate the temperature response priority mapping relationship.

[0043] A thermal inertial response model is established based on the temperature inertial characteristics of the axial thermal hysteresis region of the barrel. First, the temperature sequence of the axial thermal hysteresis region is processed using time difference analysis to extract the temperature change rate. A historical temperature weighting factor is then introduced to construct a time memory term to characterize the heat accumulation and transfer delay characteristics. Combining the local heating power input and material transport velocity, the temperature response delay is normalized and corrected to obtain the inertial response coefficient. Finally, a thermal inertial response function is established through the coupling relationship between the current temperature deviation, historical accumulated temperature, and heat transfer hysteresis coefficient. This function describes the hysteresis response capability and correction magnitude of this region to temperature regulation commands.

[0044] A thermal equilibrium correction model is established for the circumferential temperature difference diffusion zone of the mold head. First, the circumferential temperature distribution is expanded in a ring, and the deviation gradient between each angular position and the overall average temperature is calculated. A neighborhood diffusion coefficient is introduced to describe the heat transfer capacity between adjacent angles. Based on the temperature variance and range, a non-uniformity index is constructed to quantify the distribution degree of local hot and cold spots. On this basis, a local deviation suppression function is constructed to reduce the weight of high-temperature areas and increase the weight of low-temperature areas, thereby realizing a circumferential heat redistribution model and forming a thermal equilibrium correction mechanism to eliminate circumferential temperature differences.

[0045] A disturbance suppression response model is constructed based on the external airflow coupling characteristics of the cooling disturbance sensitive area. First, the transient temperature fluctuation signal caused by the cooling air ring is extracted, and its amplitude, frequency, and gradient are calculated to characterize the disturbance intensity. A spatial influence attenuation function is introduced to describe the propagation attenuation characteristics of airflow disturbance in different forming areas. A dynamic disturbance identification factor is established by combining the temperature change derivative, thereby constructing a mapping relationship between disturbance input, temperature response, and attenuation compensation, forming a reverse compensation control model to counteract the influence of external airflow.

[0046] Based on the sensitivity differences of the three response models and the thermal field stability shift results, a comprehensive matching calculation is performed. First, the suppression sensitivity coefficients of the thermal inertial response model, the thermal equilibrium correction model, and the disturbance suppression response model for temperature deviation are calculated separately to measure the adjustment capability of each model. These sensitivity coefficients are then weighted and matched with the regional stability shift in the thermal field coupling state matrix to establish a correspondence between the severity of the deviation and the control response capability. Finally, a temperature response priority mapping relationship is generated according to the suppression priority, which is used for subsequent multi-execution unit collaborative control strategy allocation.

[0047] Furthermore, based on the set of partitioned thermal response weighting factors, the forming thermal field collaborative control unit is allocated collaborative temperature adjustment parameters to generate multi-execution unit temperature correction instructions, including: Based on the temperature response priority mapping relationship, the axial thermal inertia of the segmented heating unit of the barrel is compensated in segments to generate segmented temperature compensation parameters; based on the temperature response priority mapping relationship, the circumferential heat diffusion uniformity of the annular heating unit of the die head is weighted and balanced to generate annular balance adjustment parameters; based on the temperature response priority mapping relationship, the disturbance coupling strength of the cooling air ring is compensated in reverse to generate reverse temperature drift compensation parameters; the segmented temperature compensation parameters, annular balance adjustment parameters, and reverse temperature drift compensation parameters are weighted and fused according to the partitioned thermal response weight factor set to generate the multi-execution unit temperature correction command.

[0048] Based on the temperature response priority mapping relationship, segmented compensation calculations are performed on the axial thermal inertia of the segmented heating unit of the barrel. First, the response intensity coefficient of each heating segment is determined according to the priority weight of the axial thermal hysteresis zone. Then, historical temperature hysteresis and the current set temperature difference are introduced to construct a compensation benchmark. Combining the heat conduction efficiency and material delivery speed of each segment, the temperature correction is dynamically adjusted to generate the corresponding compensation value for each segment. This compensation value is used to offset the hysteresis error caused by axial thermal inertia, thereby forming segmented temperature compensation parameters to achieve differentiated and precise temperature control along the axial direction.

[0049] Based on the temperature response priority mapping relationship, a weighted equilibrium calculation is performed on the circumferential heat diffusion unevenness problem of the annular heating unit of the die head. First, according to the priority weight of the circumferential temperature difference diffusion zone, differentiated adjustment coefficients are assigned to heating areas at different angles. Taking the circumferential temperature deviation as input, an equilibrium correction function is constructed by combining the neighborhood heat diffusion capability. This function reduces and adjusts the high-temperature area and compensates and enhances the low-temperature area. Finally, annular equilibrium adjustment parameters are generated to improve the consistency of the circumferential temperature distribution of the die head.

[0050] To address the disturbance coupling strength of the cooling airflow ring, reverse compensation calculations are performed. First, disturbance influence coefficients are extracted based on the priority weights of the cooling disturbance-sensitive area. Then, a disturbance strength assessment metric is constructed by combining the airflow fluctuation amplitude and temperature response delay characteristics. By establishing a reverse compensation function, the local temperature shift caused by the cooling disturbance is directionally canceled, achieving dynamic correction of temperature drop or fluctuation. Finally, reverse temperature drift compensation parameters are generated to reduce the interference of external airflow on the forming hot zone.

[0051] The segmented temperature compensation parameters, ring equalization adjustment parameters, and reverse temperature drift compensation parameters are integrated and processed in a unified manner. First, the three types of parameters are normalized according to the set of regional thermal response weight factors to make them the same control scale. Then, they are weighted and superimposed according to the importance weight of different thermal field regions, and constraints are introduced to ensure the coordination consistency and stability between each execution unit. Finally, multi-execution unit temperature correction commands are generated to realize the coordinated closed-loop control of the barrel, die head, and cooling system.

[0052] Furthermore, the closed-loop dynamic thermal field correction of the plastic film extrusion process using the multi-execution unit temperature correction command includes: During the plastic film extrusion molding process, the transverse thickness distribution data of the film is collected; the thermal-deformation deviation is calculated based on the mapping relationship between the transverse thickness distribution data of the film and the thermal field coupling state matrix; and the temperature correction command of the multi-execution unit is iteratively updated according to the thermal-deformation deviation.

[0053] During the extrusion molding process of plastic film, the thickness of the film in the transverse width direction is continuously scanned and collected by an online thickness measuring device to form a thickness distribution data sequence. The transverse thickness distribution is used to reflect the uniformity of material output from the die head and the local flow stability. By recording the thickness values ​​at different transverse positions in real time, the thickness fluctuation curve over time is obtained, providing basic data input for subsequent thermal-deformation coupling analysis.

[0054] Based on the mapping relationship between the transverse thickness distribution data of the thin film and the thermal field coupling state matrix, a corresponding model between the temperature field and the deformation result is established. First, the thickness deviation is converted into a deformation index and matched with the thermal field state parameters at the corresponding spatial location. Combining the weight relationship of factors such as axial heat transfer, circumferential diffusion and cooling disturbance on the deformation, the difference between thermally driven deformation and the actual thickness deviation is calculated, thereby obtaining the thermal-deformation deviation, which is used to characterize the degree of inconsistency between temperature control and molding results.

[0055] Based on the thermal deformation deviation, the temperature correction command of multiple actuators is fed back for correction. First, the deviation is decomposed into error components in three directions: axial, circumferential, and disturbance, and corresponding to the barrel heating, die head adjustment, and cooling compensation units, respectively. The compensation parameter gain of each actuator is adjusted according to the magnitude of the error to achieve adaptive correction of the control quantity. Through multiple rounds of iterative calculation, the thickness distribution gradually converges to the target uniform state, thereby achieving closed-loop dynamic optimization control.

[0056] Furthermore, during the closed-loop dynamic thermal field correction process, when the fluctuation amplitude of the lateral thickness distribution data of the thin film exceeds the preset stability threshold, the thermal field coupling state matrix and the temperature response priority mapping relationship are periodically reconstructed and updated to complete the dynamic adaptive temperature control adjustment.

[0057] A stability threshold determination mechanism is set up during the closed-loop dynamic thermal field correction process. When the fluctuation amplitude of the film lateral thickness distribution data exceeds the preset stability threshold, it is determined that the current thermal field coupling state has undergone structural shift. At this time, the periodic reconstruction of the thermal field coupling state matrix is ​​triggered, and the temperature response priority mapping relationship is updated simultaneously, so that the model can be re-adapted to the current operating condition changes. Through this adaptive reconstruction mechanism, the ability to quickly remodel and dynamically recover control under abnormal operating conditions is achieved.

[0058] Taking a three-layer co-extrusion blown film production line as an example, dynamic temperature control verification was performed on the plastic film extruder. This production line has six heating zones in the barrel and twelve annular heating control zones in the die head. The cooling system adopts an annular air ring structure. The axial temperature of the barrel, the circumferential temperature of the die head, and the disturbance temperature of the cooling air ring were simultaneously sampled with a sampling period of 2 minutes. After constructing the thermal field coupling state matrix, thermal field temporal drift analysis was performed. Table 1 shows the temperature deviation monitoring results of the barrel axial thermal hysteresis zone, the die head circumferential temperature difference diffusion zone, and the cooling disturbance sensitive zone identified under typical production conditions.

[0059] Table 1: Monitoring data of temperature deviation in the thermal instability zone

[0060] Based on the data in Table 1, draw... Figure 2 ,Depend on Figure 2 It can be seen that the temperature deviation growth rate in the cooling disturbance sensitive area is significantly higher than that in the barrel axial thermal hysteresis area and the die head circumferential temperature difference diffusion area. Among them, the cooling disturbance sensitive area reaches 5.7℃ at 14 minutes, indicating that the external airflow disturbance has the most significant impact on the thermal field stability; the barrel axial thermal hysteresis area reaches 3.1℃, showing obvious thermal inertia characteristics; the die head circumferential temperature difference diffusion area reaches 2.9℃, reflecting the phenomenon of uneven circumferential thermal diffusion.

[0061] Based on the above analysis results, a temperature response priority mapping relationship was established, and corresponding thermal response weight factors were obtained. In the example, the weight of the cooling disturbance sensitive area was set to 0.45, the weight of the barrel axial thermal hysteresis area was set to 0.33, and the weight of the die head circumferential temperature difference diffusion area was set to 0.22. Subsequently, a multi-execution unit temperature correction command was generated to coordinately adjust the cooling airflow, the die head annular heating power, and the barrel segment heating power. After closed-loop dynamic correction, the transverse thickness fluctuation of the film decreased from ±6.2% to ±2.1%, indicating that the present invention can effectively improve the thermal field stability and film thickness uniformity.

[0062] Example 2, based on the same inventive concept as the dynamic temperature control method for preparing plastic film in the foregoing examples, such as... Figure 3 As shown in the figure, this application provides a dynamic temperature control system for the preparation of plastic film using an embodiment of a plastic film machine. The system includes: Temperature sampling module 10 is used to perform multi-source temperature synchronous sampling on the molding thermal field collaborative control unit of the plastic film extruder to obtain a synchronous time-series temperature data set; characterization and modeling module 20 is used to perform multi-scale thermal field coupling state characterization and modeling based on the synchronous time-series temperature data set to obtain a thermal field coupling state matrix; drift analysis module 30 is used to perform time-series drift analysis on the thermal field coupling state matrix to identify the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, forming a thermal field instability partitioning result; weight factor construction module 40 is used to construct a temperature response priority mapping relationship based on the thermal field instability partitioning result and construct a partitioned thermal response weight factor set; parameter allocation module 50 is used to allocate collaborative temperature adjustment parameters to the molding thermal field collaborative control unit according to the partitioned thermal response weight factor set and generate multi-execution unit temperature correction instructions; thermal field correction module 60 is used to perform closed-loop dynamic thermal field correction on the plastic film extrusion process using the multi-execution unit temperature correction instructions.

[0063] Furthermore, the temperature sampling module 10 is used to perform the following operation steps: Multiple segmented thermocouple sampling nodes are arranged axially in the segmented heating unit of the barrel to periodically collect the output temperature of each heating segment, thereby obtaining the axial temperature distribution sequence of the barrel. A temperature sampling array is uniformly arranged circumferentially in the annular heating unit of the die head to perform angular discrete sampling of the heating area of ​​the die head, thereby obtaining the circumferential temperature distribution sequence of the die head. An airflow temperature feedback sampling unit is set in the air outlet area of ​​the cooling air ring to collect the temperature changes caused by the cooling airflow disturbance in real time, thereby obtaining the cooling disturbance temperature influence sequence. The axial temperature distribution sequence of the barrel, the circumferential temperature distribution sequence of the die head, and the cooling disturbance temperature influence sequence are time-reference aligned to form the synchronous time-series temperature data set.

[0064] Furthermore, the representation modeling module 20 is used to perform the following operational steps: An axial heat conduction gradient model is constructed based on the axial temperature distribution sequence of the barrel; a circumferential heat diffusion uniformity model is constructed based on the circumferential temperature distribution sequence of the die head; an external convection disturbance model is constructed based on the cooling disturbance temperature influence sequence; the axial heat conduction gradient model, the circumferential heat diffusion uniformity model, and the external convection disturbance model are coupled and mapped to generate the thermal field coupling state matrix.

[0065] Furthermore, the drift analysis module 30 is used to perform the following operation steps: The thermal field coupling state matrix is ​​decomposed by a sliding time window to obtain multiple thermal field sub-matrices at different times; the stability deviation of the multiple thermal field sub-matrices at different times is calculated to generate a thermal offset coefficient sequence; the thermal offset coefficient sequence is compared and analyzed with a preset thermal uniformity threshold interval to obtain the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone.

[0066] Furthermore, the weighting factor construction module 40 is used to perform the following operation steps: Based on the axial thermal hysteresis region of the barrel, a thermal inertial response model is constructed in conjunction with its axial temperature change inertial characteristics; based on the circumferential temperature difference diffusion region of the die head, a thermal equilibrium correction model is constructed in conjunction with its circumferential temperature diffusion gradient characteristics; based on the cooling disturbance sensitive region, a disturbance suppression response model is constructed in conjunction with its external airflow disturbance coupling characteristics; according to the sensitivity differences of the thermal inertial response model, thermal equilibrium correction model, and disturbance suppression response model to temperature deviation suppression capabilities, a matching calculation is performed with the stability offset results of the thermal field coupling state matrix to generate the temperature response priority mapping relationship.

[0067] Furthermore, the parameter allocation module 50 is used to perform the following operation steps: Based on the temperature response priority mapping relationship, the axial thermal inertia of the segmented heating unit of the barrel is compensated in segments to generate segmented temperature compensation parameters; based on the temperature response priority mapping relationship, the circumferential heat diffusion uniformity of the annular heating unit of the die head is weighted and balanced to generate annular balance adjustment parameters; based on the temperature response priority mapping relationship, the disturbance coupling strength of the cooling air ring is compensated in reverse to generate reverse temperature drift compensation parameters; the segmented temperature compensation parameters, annular balance adjustment parameters, and reverse temperature drift compensation parameters are weighted and fused according to the partitioned thermal response weight factor set to generate the multi-execution unit temperature correction command.

[0068] Furthermore, the thermal field correction module 60 is used to perform the following operation steps: During the plastic film extrusion molding process, the transverse thickness distribution data of the film is collected; the thermal-deformation deviation is calculated based on the mapping relationship between the transverse thickness distribution data of the film and the thermal field coupling state matrix; and the temperature correction command of the multi-execution unit is iteratively updated according to the thermal-deformation deviation.

[0069] Furthermore, during the closed-loop dynamic thermal field correction process, when the fluctuation amplitude of the lateral thickness distribution data of the thin film exceeds the preset stability threshold, the thermal field coupling state matrix and the temperature response priority mapping relationship are periodically reconstructed and updated to complete the dynamic adaptive temperature control adjustment.

[0070] Through the foregoing detailed description of the dynamic temperature control method for preparing plastic film in this specification, those skilled in the art can clearly understand the dynamic temperature control system for preparing plastic film in this embodiment. Since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and relevant parts can be referred to the method section.

[0071] Example 3, Figure 4 This is a schematic diagram of the electronic device provided by the dynamic temperature control method for preparing plastic film in this invention, showing an exemplary electronic device suitable for implementing the embodiments of this invention. Figure 4 The electronic device shown is merely an example and should not be construed as limiting the functionality or scope of the embodiments of the present invention. Figure 4 As shown, the electronic device includes a processor 21, a memory 22, an input device 23, and an output device 24; the number of processors 21 in the electronic device can be one or more. Figure 3 Taking a processor 21 as an example, the processor 21, memory 22, input device 23, and output device 24 in an electronic device can be connected via a bus or other means. Figure 4 Taking the bus connection between China and Israel as an example.

[0072] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A dynamic temperature control method for preparing plastic film using a plastic film machine, characterized in that, The method includes: Multi-source temperature synchronous sampling was performed on the molding thermal field coordinated control unit of the plastic film extruder to obtain a synchronous time-series temperature data set; Based on the synchronous time-series temperature data set, a multi-scale thermal field coupling state characterization model is performed to obtain the thermal field coupling state matrix. A time-series drift analysis was performed on the thermal field coupling state matrix to identify the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, thus forming a thermal field instability partitioning result. Based on the results of the thermal field instability partitioning, a temperature response priority mapping relationship is constructed, and a set of partition thermal response weight factors is constructed. Based on the set of partitioned thermal response weight factors, the forming thermal field collaborative control unit is allocated collaborative temperature adjustment parameters to generate multi-execution unit temperature correction instructions; The multi-execution unit temperature correction command is used to perform closed-loop dynamic thermal field correction in the plastic film extrusion process.

2. The dynamic temperature control method for preparing plastic film as described in claim 1, characterized in that, Multi-source synchronous temperature sampling was performed on the molding thermal field coordinated control unit of the plastic film extruder to obtain a synchronous time-series temperature data set, including: Multiple segmented thermocouple sampling nodes are arranged along the axial direction in the segmented heating unit of the barrel to periodically collect the output temperature of each heating segment and obtain the axial temperature distribution sequence of the barrel. A temperature sampling array is uniformly arranged along the circumference of the annular heating unit of the mold head, and the heating area of ​​the mold head is sampled at an angle to obtain the circumferential temperature distribution sequence of the mold head. An airflow temperature feedback sampling unit is set up in the air outlet area of ​​the cooling air ring to collect the temperature changes caused by the cooling airflow disturbance in real time and obtain the cooling disturbance temperature influence sequence. The axial temperature distribution sequence of the barrel, the circumferential temperature distribution sequence of the die head, and the temperature influence sequence of cooling disturbance are aligned with the time reference to form the synchronous time-series temperature data set.

3. The dynamic temperature control method for preparing plastic film using a plastic film machine as described in claim 2, characterized in that, Based on the aforementioned synchronous time-series temperature data set, a multi-scale thermal field coupling state characterization model is performed to obtain a thermal field coupling state matrix, including: An axial heat conduction gradient model is constructed based on the axial temperature distribution sequence of the barrel. A circumferential heat diffusion uniformity model is constructed based on the circumferential temperature distribution sequence of the mold head; An external convection disturbance model is constructed based on the aforementioned cooling disturbance temperature influence sequence; The axial heat conduction gradient model, the circumferential heat diffusion uniformity model, and the external convection disturbance model are coupled and mapped to generate the thermal field coupling state matrix.

4. The dynamic temperature control method for preparing plastic film as described in claim 1, characterized in that, A time-series drift analysis was performed on the thermal field coupling state matrix to identify the axial thermal hysteresis region of the barrel, the circumferential temperature difference diffusion region of the die head, and the cooling disturbance sensitive region, including: The thermal field coupling state matrix is ​​decomposed by a sliding time window to obtain thermal field sub-matrices at multiple time points; Stability deviation calculations are performed on the thermal field submatrices at the multiple time points to generate a thermal offset coefficient sequence; By comparing and analyzing the thermal offset coefficient sequence with the preset thermal uniformity threshold range, the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone are obtained.

5. The dynamic temperature control method for preparing plastic film using a plastic film machine as described in claim 4, characterized in that, Based on the thermal instability partitioning results, a temperature response priority mapping relationship is constructed, including: Based on the axial thermal hysteresis zone of the barrel, a thermal inertial response model is constructed in conjunction with its axial temperature change inertial characteristics. Based on the circumferential temperature difference diffusion zone of the mold head, a thermal equilibrium correction model is constructed in combination with its circumferential temperature diffusion gradient characteristics. Based on the aforementioned cooling disturbance sensitive area, a disturbance suppression response model is constructed by combining its external airflow disturbance coupling characteristics; Based on the sensitivity differences in temperature deviation suppression capabilities among the thermal inertial response model, thermal equilibrium correction model, and disturbance suppression response model, a matching calculation is performed with the stability offset results of the thermal field coupling state matrix to generate the temperature response priority mapping relationship.

6. The dynamic temperature control method for preparing plastic film using a plastic film machine as described in claim 5, characterized in that, Based on the set of partitioned thermal response weighting factors, the molding thermal field collaborative control unit is allocated collaborative temperature adjustment parameters, and a multi-execution unit temperature correction command is generated, including: Based on the temperature response priority mapping relationship, the axial thermal inertia of the barrel segmented heating unit is calculated in segments to generate segmented temperature compensation parameters. Based on the temperature response priority mapping relationship, a weighted equalization calculation is performed on the circumferential heat diffusion uniformity of the annular heating unit of the mold head to generate annular equalization adjustment parameters. Based on the temperature response priority mapping relationship, the disturbance coupling strength of the cooling air ring is calculated in reverse to generate reverse temperature drift compensation parameters. The segmented temperature compensation parameters, ring equalization adjustment parameters, and reverse temperature drift compensation parameters are weighted and fused according to the set of partitioned thermal response weight factors to generate the multi-execution unit temperature correction command.

7. The dynamic temperature control method for preparing plastic film using a plastic film machine as described in claim 1, characterized in that, The closed-loop dynamic thermal field correction of the plastic film extrusion process is performed using the multi-execution unit temperature correction command, including: Data on the transverse thickness distribution of the film were collected during the plastic film extrusion process. The thermal-deformation deviation is calculated based on the mapping relationship between the thin film lateral thickness distribution data and the thermal field coupling state matrix; The temperature correction command of the multi-execution unit is iteratively updated based on the thermal deformation deviation.

8. The dynamic temperature control method for preparing plastic film using a plastic film machine as described in claim 7, characterized in that, During the closed-loop dynamic thermal field correction process, when the fluctuation amplitude of the film lateral thickness distribution data exceeds the preset stability threshold, the thermal field coupling state matrix and temperature response priority mapping relationship are periodically reconstructed and updated to complete the dynamic adaptive temperature control adjustment.

9. A dynamic temperature control system for the preparation of plastic film using a plastic film machine, characterized in that, For implementing the dynamic temperature control method for preparing plastic film using any one of claims 1 to 8, the system comprises: The temperature sampling module is used to perform multi-source temperature synchronous sampling on the molding thermal field coordinated control unit of the plastic film extruder to obtain a synchronous time-series temperature data set. The characterization modeling module is used to perform multi-scale thermal field coupling state characterization modeling based on the synchronous time-series temperature data set, and obtain the thermal field coupling state matrix. The drift analysis module is used to perform time-series drift analysis on the thermal field coupling state matrix, identify the axial thermal hysteresis zone of the barrel, the circumferential temperature difference diffusion zone of the die head, and the cooling disturbance sensitive zone, and form thermal field instability partitioning results. The weighting factor construction module is used to construct a temperature response priority mapping relationship based on the thermal field instability partitioning results, and to construct a set of partitioned thermal response weighting factors. The parameter allocation module is used to allocate the coordinated temperature adjustment parameters of the molding thermal field coordinated control unit according to the set of partitioned thermal response weight factors, and generate temperature correction instructions for multiple execution units. The thermal field correction module is used to perform closed-loop dynamic thermal field correction on the plastic film extrusion process using the multi-execution unit temperature correction command.

10. An electronic device, characterized in that, The electronic device includes: processor; Memory used to store the processor's executable instructions; The processor is used to execute the dynamic temperature control method for preparing plastic film machine according to any one of claims 1 to 8.

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