Tension self-adaptive adjusting method for PET packing belt stretching process

Abstract

The application relates to the technical field of PET packing belt processing, and discloses a PET packing belt tension self-adaptive adjusting method in a stretching process, which comprises the following steps: collecting water temperature parameters and belt material parameters of a heating and stretching device in a PET packing belt production line; evaluating the heating state of the belt material according to the water temperature parameters, judging the softening degree of the belt material in combination with the thickness of the belt material, and dividing the state of the belt material according to the softening degree of the belt material; when the belt material is in an under-softening state or an over-softening state, the water temperature parameters are adjusted so that the state of the belt material is in a moderate softening state; when the belt material is in the moderate softening state, a tension deviation value of a belt material tension value and a preset tension value is calculated, whether the belt material running speed is adjusted is judged according to the tension deviation value, and if the adjustment is judged, the belt material running speed is adjusted according to the tension deviation value. The application realizes the stage-by-stage self-adaptive control of the PET packing belt stretching process.

Description

Technical Field

[0001] This invention relates to the field of PET strapping processing technology, and more specifically, to a method for adaptive tension adjustment during the stretching process of PET strapping. Background Technology

[0002] In the existing PET strapping production process, the strapping material needs to undergo heat stretching treatment to improve its mechanical properties and meet subsequent use requirements. Traditional production lines typically soften the strapping material using a heated water bath and apply a certain tension to it using a traction device, causing it to form a finished product with a certain strength and ductility during the stretching process. However, in actual production, the water temperature of the heated water bath, the strapping speed, and the tension control are often adjusted independently, lacking an effective collaborative control mechanism, making it difficult to form a unified closed-loop control among the various process parameters.

[0003] Specifically, existing technologies typically rely on a single parameter for control, making it difficult to reflect the actual heating status and softening degree of the strip during the heating process. When the water temperature is set improperly or the strip's running speed fluctuates, the strip may experience insufficient or excessive heating, affecting its softening uniformity and leading to unstable tension distribution during stretching. Furthermore, directly adjusting the tension before the strip has reached a suitable softening state can easily cause localized stress concentration due to high material rigidity or uneven softening, increasing the risk of strip breakage or uneven stretching.

[0004] Therefore, it is necessary to provide an adaptive tension adjustment method for the stretching process of PET strapping to solve the problems of uneven softening and unstable tension distribution caused by the lack of coordinated control of heating and stretching process parameters in the existing PET strapping production. Summary of the Invention

[0005] In view of this, the present invention proposes an adaptive tension adjustment method for the stretching process of PET strapping, which aims to solve the problems of uneven softening and unstable tension distribution of the strapping material caused by the lack of coordinated control of heating and stretching process parameters in the existing PET strapping production.

[0006] This invention proposes a method for adaptive tension adjustment during the stretching process of PET strapping, comprising: Collect water temperature parameters and strip parameters of the heating and stretching device in the PET strapping production line; wherein, the strip parameters include strip tension value, strip thickness and strip running speed; The heating state of the strip is evaluated based on the water temperature parameters, and the degree of softening of the strip is determined in combination with the strip thickness. The strip state is then classified according to the degree of softening. The strip state includes under-softened state, moderately softened state, and over-softened state. When the strip is in a state of under-softening or over-softening, the water temperature parameter is adjusted to bring the strip to a state of moderate softening. When the strip is in a moderately softened state, the tension deviation between the strip tension value and the preset tension value is calculated. Based on the tension deviation value, it is determined whether the strip running speed should be adjusted. If it is determined that adjustment is needed, the strip running speed is adjusted according to the tension deviation value.

[0007] Furthermore, after collecting the water temperature parameters and strip material parameters of the heating and stretching device in the PET strapping production line, the water temperature parameters and strip material parameters are preprocessed, including: The collected water temperature and strip parameters are filtered. The units for strip thickness and strip running speed are standardized. The water temperature parameters and strip parameters are synchronously calibrated to ensure that the water temperature parameters and strip parameters correspond consistently in the time dimension.

[0008] Furthermore, the evaluation of the thermal state of the strip based on the water temperature parameters includes: The synchronously corrected water temperature parameters are used as the characterization parameters of the heating temperature of the strip in the heating water tank. The residence time of the strip in the heating water tank is determined by combining the strip running speed, so as to characterize the heating time of the strip; Based on the characterization parameters of the heating temperature and the heating time, the degree of heating of the strip is determined, and the heating state of the strip is graded and evaluated according to the degree of heating sufficiency.

[0009] Furthermore, the step of determining the degree of heating sufficiency of the strip based on the characterization parameters of the heating temperature and the heating duration, and then classifying and evaluating the heating state of the strip based on the degree of heating sufficiency, includes: The temperature characteristics of the heated material are compared with a preset temperature reference range to determine the temperature range in which the strip is located. The heating time is compared with the preset heating time range to determine whether the heating time of the strip meets the preset requirements. Based on the matching of the temperature range and the heating time, the degree of heating of the strip is comprehensively determined: when the characteristic parameter of the heating temperature is lower than the preset temperature reference range or the heating time is lower than the preset heating time range, it is determined to be insufficient heating; when the characteristic parameter of the heating temperature is within the preset temperature reference range and the heating time is within the preset heating time range, it is determined to be moderate heating; when the characteristic parameter of the heating temperature is higher than the preset temperature reference range or the heating time exceeds the preset heating time range, it is determined to be overheated.

[0010] Furthermore, when determining the degree of softening of the strip in conjunction with its thickness, the following steps are included: Set the thickness threshold; If the strip thickness is less than or equal to the thickness threshold and the heating level is moderate, the strip softening level is determined to be moderately softened; if the strip thickness is less than or equal to the thickness threshold and the heating level is excessive, the strip softening level is determined to be over-softened; if the strip thickness is less than or equal to the thickness threshold and the heating level is insufficient, the strip softening level is determined to be under-softened. If the strip thickness is greater than the thickness threshold and the heating level is moderate, the strip softening level is determined to be under-softened; if the strip thickness is greater than the thickness threshold and the heating level is excessive, the strip softening level is determined to be moderately softened; if the strip thickness is greater than the thickness threshold and the heating level is insufficient, the strip softening level is determined to be under-softened.

[0011] Furthermore, when classifying the strip state according to the degree of softening, the following steps are included: When the strip softening degree is under-softened, the strip state is classified as under-softened state; When the strip softening degree is moderately softened, the strip condition is classified as moderately softened. When the strip softening degree is over-softened, the strip condition is classified as over-softened.

[0012] Furthermore, adjusting the water temperature parameter to bring the strip to a moderately softened state when it is in a sub-softened or over-softened state includes: When the strip is in a sub-softened state, the heating unit of the heating and stretching device is controlled to gradually increase the water temperature at a preset heating rate; when the strip is in a super-softened state, the heating unit is controlled to gradually decrease the water temperature at a preset cooling rate. During the adjustment of water temperature parameters, strip parameters are continuously collected and the degree of strip softening is judged in real time; when the degree of strip softening reaches the appropriate level, the adjustment of water temperature parameters is stopped and the current water temperature is maintained.

[0013] Furthermore, when calculating the tension deviation between the strip tension value and the preset tension value when the strip is in a moderately softened state, the calculation includes: The tension deviation value is the difference between the strip tension value and the preset tension value.

[0014] Furthermore, when determining whether to adjust the strip running speed based on the tension deviation value, the following steps are included: Set the deviation threshold range; If the tension deviation value is within the deviation threshold range, it is determined that the strip running speed will not be adjusted. If the tension deviation value is not within the deviation threshold range, it is determined that the strip running speed should be adjusted.

[0015] Furthermore, when adjusting the strip running speed based on the tension deviation value, the following steps are included: When the tension deviation value is less than the minimum value of the deviation threshold range, the difference between the minimum value of the deviation threshold range and the tension deviation value is calculated and recorded as the first difference; the strip running speed is adjusted by setting a first adjustment coefficient according to the first difference; wherein, 1 > first adjustment coefficient > 0, and the first adjustment coefficient is inversely proportional to the first difference, and the adjusted strip running speed is the product of the strip running speed before adjustment and the first adjustment coefficient; When the tension deviation value is greater than the maximum value of the deviation threshold range, the difference between the tension deviation value and the maximum value of the deviation threshold range is calculated and recorded as the second difference value; the second adjustment coefficient is set according to the second difference value to adjust the strip running speed; wherein, 1 < second adjustment coefficient < 1.5, and the second adjustment coefficient is proportional to the second difference value, and the adjusted strip running speed is the product of the strip running speed before adjustment and the second adjustment coefficient.

[0016] Compared with existing technologies, the advantages of this invention are as follows: By collaboratively collecting and analyzing the water temperature parameters and strip parameters in the heating and stretching device, this invention organically couples the strip's heating state, softening degree, and tension adjustment process, achieving phased adaptive control of the PET strapping stretching process. Specifically, when the strip has not reached a moderately softened state, the heating conditions of the strip are improved by adjusting the water temperature parameters first. After the strip reaches a moderately softened state, the running speed of the strip is finely adjusted based on the tension deviation, thereby avoiding the control inaccuracy problem caused by directly adjusting the tension when the material state is unstable. In summary, this invention can effectively improve the accuracy and stability of tension control, reduce the risk of strip breakage, uneven thickness, and performance fluctuations, while improving the continuity of the production process and the consistency of product quality. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of a method for adaptive tension adjustment during the stretching process of PET packing straps provided in an embodiment of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] In some embodiments of this application, see Figure 1 As shown, this embodiment provides a method for adaptive tension adjustment during the stretching process of PET strapping, including the following steps: S100. Collect the water temperature parameters and strip parameters of the heating and stretching device in the PET strapping production line; wherein, the strip parameters include strip tension value, strip thickness and strip running speed; S200. Evaluate the heating state of the strip based on the water temperature parameters, and determine the degree of softening of the strip in combination with the strip thickness. Classify the strip state according to the degree of softening; wherein, the strip state includes under-softened state, moderately softened state and over-softened state. S300. When the strip is in a state of under-softening or over-softening, the water temperature parameter is adjusted to make the strip state of moderate softening. S400. When the strip is in a moderately softened state, calculate the tension deviation between the strip tension value and the preset tension value, and determine whether to adjust the strip running speed based on the tension deviation value. If it is determined to adjust, then adjust the strip running speed based on the tension deviation value.

[0020] It is understood that this invention achieves phased adaptive control of the PET strapping stretching process by collaboratively collecting and analyzing water temperature and strip parameters in the heating and stretching device, organically coupling the strip's heating state, softening degree, and tension adjustment process. Specifically, when the strip has not reached a moderately softened state, the heating conditions of the strip are improved by adjusting the water temperature parameters first. After the strip reaches a moderately softened state, the running speed of the strip is finely adjusted based on the tension deviation, thereby avoiding the control inaccuracy caused by directly adjusting the tension when the material state is unstable. In summary, this invention can effectively improve the accuracy and stability of tension control, reduce the risk of strip breakage, uneven thickness, and performance fluctuations, and improve the continuity of the production process and the consistency of product quality.

[0021] Specifically, in the implementation process, a temperature sensor can be installed in the water tank of the heating and stretching device to collect water temperature parameters in real time. A tension sensor can be installed at the traction roller or guide roller along the strip running path to obtain the strip tension value. An online thickness gauge can be installed at the strip output end to obtain the strip thickness. The strip running speed can be obtained through an encoder connected to the traction motor. After the collected parameters are processed by the controller, the heating time of the strip in the water tank is first determined based on the water temperature parameters and the strip running speed. The heating effect is then corrected based on the strip thickness to obtain the degree of softening and corresponding state of the strip. When it is determined that the strip is in an under-softened or over-softened state, the water temperature in the water tank is adjusted by controlling the heating unit to bring the strip into a moderately softened state. When the strip is in a moderately softened state, the controller calculates the tension deviation based on the current tension value and the preset tension value, and determines whether the strip running speed needs to be adjusted. If adjustment is needed, the strip running speed is changed by adjusting the speed of the traction motor to gradually bring the strip tension closer to the preset range, thereby realizing closed-loop adaptive control of the entire stretching process.

[0022] In some specific embodiments of this application, after collecting the water temperature parameters and strip material parameters of the heating and stretching device in the PET strapping production line, the water temperature parameters and strip material parameters are preprocessed, including: The collected water temperature and strip parameters are filtered. The units for strip thickness and strip running speed are standardized. The water temperature parameters and strip parameters are synchronously calibrated to ensure that the water temperature parameters and strip parameters correspond consistently in the time dimension.

[0023] Understandably, preprocessing the collected water temperature and strip parameters helps improve the accuracy and stability of subsequent heat state assessment and tension adjustment. Among these measures, filtering effectively eliminates random noise and instantaneous fluctuations introduced during sensor acquisition, preventing abnormal data from interfering with control decisions; unit standardization eliminates dimensional differences caused by different measurement units, allowing parameters to be compared and analyzed under the same standard; and synchronous calibration ensures the consistency of water temperature parameters with strip tension, thickness, and operating speed in the time dimension, avoiding misjudgments caused by asynchronous sampling timing.

[0024] In the specific implementation process, temperature sensors installed in the heating water tank, tension sensors at the traction rollers, online thickness gauges, and encoders collect water temperature parameters, strip tension values, strip thickness, and strip running speed, respectively, and transmit the collected data to the controller. In the controller, moving average filtering or median filtering can be used to filter the water temperature parameters and tension values ​​to remove abrupt noise. The strip thickness and running speed are uniformly converted according to preset unit standards, such as unifying the thickness to millimeters and the speed to meters per second. At the same time, based on a unified sampling period, various parameter data are timestamped, and synchronous correction is performed through interpolation or alignment to match the water temperature parameters and strip parameters at the same time, thereby forming a consistent parameter data sequence for subsequent heating state assessment and tension adjustment control.

[0025] In some specific embodiments of this application, the evaluation of the thermal state of the strip based on the water temperature parameter includes: The synchronously corrected water temperature parameters are used as the characterization parameters of the heating temperature of the strip in the heating water tank. The residence time of the strip in the heating water tank is determined by combining the strip running speed, so as to characterize the heating time of the strip; Based on the characterization parameters of the heating temperature and the heating time, the degree of heating of the strip is determined, and the heating state of the strip is graded and evaluated according to the degree of heating sufficiency.

[0026] Understandably, by jointly analyzing water temperature parameters and strip running speed to characterize the strip's heating temperature and heating time respectively, a comprehensive assessment of the strip's heating state can be conducted from two dimensions: "temperature" and "time." Compared to judging based solely on a single temperature parameter, this approach more accurately reflects the actual heating situation of the strip in the heating tank. The heating effect of the strip in the tank depends not only on the water temperature but also on the strip's residence time. Introducing residence time as a heating duration indicator effectively avoids underheating or overheating issues caused by speed fluctuations. Furthermore, by grading and evaluating the degree of heating sufficiency, a clear basis can be provided for subsequent softening degree judgment, making water temperature and tension adjustment processes more targeted and controllable, which is beneficial for improving the stability of the stretching process and the consistency of finished product quality.

[0027] In the specific implementation process, the effective length parameter of the heating water tank is preset in the controller, and the time required for the strip to pass through the heating water tank is calculated in combination with the strip running speed collected by the encoder, which is used as the residence time of the strip. At the same time, the synchronously corrected water temperature parameter is directly input into the controller as an approximate value of the strip's heating temperature. Based on this, the heating temperature can be divided into several temperature ranges, and the residence time can be divided into several time ranges. The degree of heating of the strip is determined by looking up tables or rule matching. For example, when the water temperature is within the target temperature range and the residence time meets the preset time range, it is judged as moderate heating; when the water temperature is too low or the residence time is insufficient, it is judged as insufficient heating; when the water temperature is too high or the residence time is too long, it is judged as overheating. The above method realizes the graded evaluation of the heating state of the strip and provides a basis for subsequent softening state determination and parameter adjustment.

[0028] In some specific embodiments of this application, the step of determining the degree of heating sufficiency of the strip based on the characterization parameters of the heating temperature and the heating duration, and classifying and evaluating the heating state of the strip based on the degree of heating sufficiency, includes: The temperature characteristics of the heated material are compared with a preset temperature reference range to determine the temperature range in which the strip is located. The heating time is compared with the preset heating time range to determine whether the heating time of the strip meets the preset requirements. Based on the matching of the temperature range and the heating time, the degree of heating of the strip is comprehensively determined: when the characteristic parameter of the heating temperature is lower than the preset temperature reference range or the heating time is lower than the preset heating time range, it is determined to be insufficient heating; when the characteristic parameter of the heating temperature is within the preset temperature reference range and the heating time is within the preset heating time range, it is determined to be moderate heating; when the characteristic parameter of the heating temperature is higher than the preset temperature reference range or the heating time exceeds the preset heating time range, it is determined to be overheated.

[0029] Understandably, by comparing the heating temperature and heating time with preset ranges respectively, and comprehensively judging the degree of heating based on the matching relationship between the two, the assessment of the heating state is transformed from a single threshold judgment to a multi-condition joint judgment, thereby improving the accuracy and robustness of the assessment results. In particular, by considering both the temperature range and the heating time simultaneously, the problem of misjudgment caused by relying solely on temperature or time as a single factor can be effectively avoided. Furthermore, by dividing the heating state into three levels—insufficient heating, moderate heating, and excessive heating—a clear grading basis can be provided for subsequent judgment of softening degree and water temperature adjustment, thereby improving the precision and stability of the entire stretching control process.

[0030] In practical implementation, the controller pre-stores the judgment rules for temperature and time ranges. It compares the synchronously calibrated water temperature parameters with the preset temperature reference range to determine the current temperature range of the strapping. Simultaneously, it compares the residence time calculated based on the strapping speed and the length of the heating tank with the preset heating time range. Then, it matches the results according to the pre-set judgment logic. For example, if the temperature is below the target range or the residence time is insufficient, it is judged as insufficient heating; if both temperature and time are within the target range, it is judged as moderate heating; if the temperature is above the target range or the residence time is too long, it is judged as overheating. In practical applications, multiple temperature and time ranges can be set to achieve finer-grained grading and evaluation to adapt to the production needs of different specifications of strapping.

[0031] Furthermore, the settings for the preset temperature reference range and preset heating time range can be determined based on the thermal softening characteristics of PET material and actual production experience. Specifically, the tensile effect of the strip under different water temperatures and residence times can be tested experimentally. The water temperature range and residence time range corresponding to the strip reaching ideal tensile properties (such as elongation, strength, and surface quality) can be recorded, and this range can be used as the target temperature reference range and target heating time range. At the same time, the above ranges can be appropriately modified according to the strip thickness, production speed, and equipment structural parameters. For example, for thicker strips, the temperature reference range can be appropriately increased or the heating time range can be extended. For higher operating speeds, the water temperature can be increased or the time threshold judgment range can be shortened accordingly. This makes the set preset temperature reference range and preset heating time range more consistent with actual working conditions, improving the adaptability and effectiveness of the control strategy.

[0032] In some specific embodiments of this application, the determination of the softening degree of the strip in conjunction with the strip thickness includes: Set the thickness threshold; If the strip thickness is less than or equal to the thickness threshold and the heating level is moderate, the strip softening level is determined to be moderately softened; if the strip thickness is less than or equal to the thickness threshold and the heating level is excessive, the strip softening level is determined to be over-softened; if the strip thickness is less than or equal to the thickness threshold and the heating level is insufficient, the strip softening level is determined to be under-softened. If the strip thickness is greater than the thickness threshold and the heating level is moderate, the strip softening level is determined to be under-softened; if the strip thickness is greater than the thickness threshold and the heating level is excessive, the strip softening level is determined to be moderately softened; if the strip thickness is greater than the thickness threshold and the heating level is insufficient, the strip softening level is determined to be under-softened.

[0033] Understandably, introducing strip thickness as a correction factor based on the degree of heating sufficiency allows for a secondary assessment of the strip softening degree, making the softening state judgment more closely reflect actual process characteristics. Since PET strips of different thicknesses exhibit differences in heat conduction efficiency and internal temperature distribution under the same heating conditions, thinner strips are more likely to achieve overall softening, while thicker strips may show surface softening but insufficient internal heating. By setting a thickness threshold and combining it with the degree of heating sufficiency for graded judgment, misjudgments caused by relying solely on temperature and time can be effectively avoided. For example, under moderate heating conditions, thin strips can be directly judged as moderately softened, while thicker strips require further compensation for heating conditions; otherwise, they will still be judged as under-softened. This improves the accuracy and consistency of softening degree judgment, which is beneficial for the stable execution of subsequent tension control and the uniformity control of product quality.

[0034] In the specific implementation process, the thickness of the strip can be obtained in real time through an online thickness gauge and input into the controller. The controller classifies the strip according to the preset thickness threshold. When the strip thickness does not exceed the thickness threshold, the softening state is determined directly based on the degree of heat treatment. When the strip thickness exceeds the thickness threshold, the degree of heat treatment is corrected. For example, if the heating is moderate, it is still determined to be under-softened, so as to prompt the system to further increase the water temperature or extend the heating time. In actual production, multiple sets of thickness thresholds can also be set according to different product specifications to adapt to PET strapping with different widths or thickness grades, thereby achieving more refined control of the softening state.

[0035] Preferably, the thickness threshold can be determined experimentally based on the typical specification range and thermal conductivity characteristics of PET strapping. Specifically, different thicknesses of strapping can be selected and tensile tests can be conducted under the same water temperature and residence time conditions. The critical thickness value at which the strapping reaches the ideal softening state (i.e., uniform stretching with no obvious difference between inner and outer layers) can be recorded, and this critical thickness or its vicinity can be used as the thickness threshold. In practical applications, the threshold can be dynamically corrected in combination with production speed and water temperature conditions. For example, the thickness threshold can be appropriately reduced under high-speed conditions to improve the conservatism of the judgment. In addition, the thickness threshold can also be set as an adjustable parameter, which can be set by the operator according to product specifications or process requirements, thereby improving the adaptability and engineering feasibility of the method.

[0036] In some specific embodiments of this application, the step of classifying the strip state according to the degree of softening includes: When the strip softening degree is under-softened, the strip state is classified as under-softened state; When the strip softening degree is moderately softened, the strip condition is classified as moderately softened. When the strip softening degree is over-softened, the strip condition is classified as over-softened.

[0037] Understandably, by directly mapping the softening degree of the strip to the corresponding strip state, the evaluation result of the softening degree can be expressed in a clear and intuitive state form, thus providing a clear and unified basis for subsequent control strategies. Compared with using only continuous numerical values ​​to describe the softening degree, dividing it into three discrete states—under-softened, moderately softened, and over-softened—helps simplify control logic, improve the stability and interpretability of judgments, and facilitates the development of targeted control strategies for different states, such as corresponding to heating, holding, or cooling operations, thereby improving overall control efficiency and response accuracy. In addition, it can reduce the problem of frequent state switching caused by small parameter fluctuations, improving operational stability and reliability.

[0038] In practical implementation, the correspondence between softening degree and state can be predefined in the controller. The softening degree value or level of the current strip can be obtained through real-time calculation. Then, this value is matched with the preset state classification rules. For example, if the softening degree index is lower than the first threshold, it is judged as under-softened state; if it is between the first and second thresholds, it is judged as moderately softened state; and if it is higher than the second threshold, it is judged as over-softened state. In practical applications, the softening degree index can be calculated by combining parameters such as the degree of heating and strip thickness. The state classification can be completed by looking up tables or rule judgment methods, thereby realizing real-time and stable identification of strip state and providing a reliable input basis for subsequent water temperature adjustment and tension control.

[0039] In some specific embodiments of this application, adjusting the water temperature parameter to bring the strip to a moderately softened state when the strip is in a sub-softened or over-softened state includes: When the strip is in a sub-softened state, the heating unit of the heating and stretching device is controlled to gradually increase the water temperature at a preset heating rate; when the strip is in a super-softened state, the heating unit is controlled to gradually decrease the water temperature at a preset cooling rate. During the adjustment of water temperature parameters, strip parameters are continuously collected and the degree of strip softening is judged in real time; when the degree of strip softening reaches the appropriate level, the adjustment of water temperature parameters is stopped and the current water temperature is maintained.

[0040] Understandably, by implementing closed-loop regulation of the water temperature parameter when the strip is in an under-softened or over-softened state, the water temperature can dynamically change according to the actual state of the strip. Furthermore, by using preset heating and cooling rates, the water temperature can be smoothly adjusted, avoiding sudden temperature changes that could impact the strip. Simultaneously, strip parameters are continuously collected during the adjustment process, and the degree of softening is judged in real time. When a suitable softening state is reached, the adjustment is immediately stopped and the current water temperature is maintained, thus forming a feedback-based adaptive control mechanism that can quickly converge to the optimal process state. Compared to traditional open-loop or fixed-parameter control methods, this embodiment can effectively reduce over-adjustment or under-adjustment phenomena, improve control accuracy and system stability, while reducing energy consumption and improving product quality consistency.

[0041] In practice, the water temperature can be adjusted by a temperature control unit (such as an electric heater or heat exchanger) installed in the heating water tank, and the controller outputs control commands based on the real-time determination of the softening state. When the softening state is determined to be under-softened, the controller gradually increases the heating power according to the preset heating rate, so that the water temperature rises slowly. When the softening state is determined to be over-softened, the heating power is reduced or the cooling device is activated, so that the water temperature gradually decreases. During the adjustment process, the controller continuously receives data from the tension sensor, thickness sensor and temperature sensor, and updates the softening degree of the strip in real time. Once the strip is detected to have entered a moderately softened state, the temperature adjustment is stopped and the current water temperature is maintained to ensure the stable operation of the production process.

[0042] Furthermore, the preset heating rate setting can be determined based on the thermal response characteristics of the PET material and the actual process parameters of the production line. Specifically, the softening response time and quality performance of the strip at different heating rates can be tested experimentally to select a rate that ensures the strip gradually reaches the target softening state without causing over-softening or excessive thermal stress due to excessively rapid heating. In practical applications, the heating rate can be set as an adjustable parameter and dynamically adjusted according to the strip thickness, operating speed, and the difference between the current and target temperatures. For example, when the temperature difference is large or the strip is thick, the heating rate can be appropriately increased, and when approaching the target state, the heating rate can be gradually decreased to achieve smoother and more precise temperature control, thereby improving the adaptability and stability of the entire system.

[0043] In some specific embodiments of this application, when the strip is in a moderately softened state, calculating the tension deviation between the strip tension value and the preset tension value includes: The tension deviation value is the difference between the strip tension value and the preset tension value.

[0044] Understandably, determining the tension deviation value by directly subtracting the strip tension value from the preset tension value makes the calculation of tension deviation simpler and more intuitive, with good interpretability and calculation efficiency. Using the difference form can directly reflect the direction and magnitude of the current tension deviation from the target tension, thus providing a clear basis for subsequent operating speed adjustment. For example, positive or negative deviations correspond to different adjustment directions.

[0045] In the specific implementation process, the tension sensor set in the tension section can collect the strip tension value in real time, and the controller can store it in advance or obtain the preset tension value according to the process setting. The controller performs real-time difference calculation between the two, for example, using the method of "tension deviation value = strip tension value - preset tension value". When the calculation result is positive, it means that the current tension is higher than the target tension, and when the result is negative, it means that the current tension is lower than the target tension.

[0046] In some specific embodiments of this application, determining whether to adjust the strip running speed based on the tension deviation value includes: Set the deviation threshold range; If the tension deviation value is within the deviation threshold range, it is determined that the strip running speed will not be adjusted. If the tension deviation value is not within the deviation threshold range, it is determined that the strip running speed should be adjusted.

[0047] Understandably, by introducing a threshold range judgment process for tension deviation, the strip running speed is only adjusted when the tension deviation exceeds the allowable range, thereby avoiding frequent triggering of control actions due to small fluctuations in tension.

[0048] In a specific implementation, the controller pre-sets a tension deviation threshold range, for example, setting an upper and lower fluctuation range as the allowable deviation range centered on a preset tension value; the controller calculates the current tension deviation value in real time and compares it with the threshold range. When the deviation value is within the range, the current tension is considered to be within the acceptable fluctuation range, and there is no need to adjust the strip running speed; when the deviation value exceeds the range, the speed adjustment mechanism is triggered, and the running speed is adjusted accordingly according to the direction and magnitude of the deviation, thereby gradually pulling the tension back to the target range.

[0049] Furthermore, the setting of the deviation threshold range can be comprehensively determined based on the equipment accuracy, strip material characteristics, and production process requirements. For example, tensile quality data of the strip under different tension deviations (such as thickness uniformity, breaking strength, and surface quality) can be collected experimentally to determine a range within which product quality is stable and equipment operation is smooth, and this range can be set as the deviation threshold range. In practical applications, this threshold range can also be dynamically adjusted according to factors such as strip thickness, operating speed, or ambient temperature. For example, the threshold range can be appropriately widened during high-speed production to reduce frequent adjustments, while the threshold range can be narrowed during fine processing to improve control accuracy, thereby achieving a more flexible and adaptable control strategy.

[0050] In some specific embodiments of this application, adjusting the strip running speed according to the tension deviation value includes: When the tension deviation value is less than the minimum value of the deviation threshold range, the difference between the minimum value of the deviation threshold range and the tension deviation value is calculated and recorded as the first difference; the strip running speed is adjusted by setting a first adjustment coefficient according to the first difference; wherein, 1 > first adjustment coefficient > 0, and the first adjustment coefficient is inversely proportional to the first difference, and the adjusted strip running speed is the product of the strip running speed before adjustment and the first adjustment coefficient; When the tension deviation value is greater than the maximum value of the deviation threshold range, the difference between the tension deviation value and the maximum value of the deviation threshold range is calculated and recorded as the second difference value; the second adjustment coefficient is set according to the second difference value to adjust the strip running speed; wherein, 1 < second adjustment coefficient < 1.5, and the second adjustment coefficient is proportional to the second difference value, and the adjusted strip running speed is the product of the strip running speed before adjustment and the second adjustment coefficient.

[0051] Understandably, by introducing a segmented adjustment mechanism when the tension deviation exceeds the threshold range, and setting a first adjustment coefficient and a second adjustment coefficient related to the deviation difference, the strip running speed can be finely adjusted according to the direction and amplitude of the tension deviation. Specifically, when the tension deviation is below the lower limit, the tension is increased by reducing the running speed (the first adjustment coefficient is less than 1), and when the tension deviation is above the upper limit, the tension is decreased by increasing the running speed (the second adjustment coefficient is greater than 1), thereby achieving dynamic closed-loop control of the tension. At the same time, an inverse or direct proportional relationship is established between the adjustment coefficient and the deviation difference, so that the adjustment amplitude changes with the degree of deviation. The larger the deviation, the more obvious the adjustment, and the smaller the deviation, the smoother the adjustment, thereby avoiding system shock and oscillation problems caused by abrupt adjustment and improving the stability and response accuracy of the control process. In addition, this segmented control strategy can achieve more flexible adjustment within different deviation ranges, effectively improving the robustness and adaptability of tension control.

[0052] In the specific implementation process, the controller compares the real-time collected tension deviation value with the preset deviation threshold range. When the tension deviation value is less than the lower limit of the threshold, the first difference (i.e., the difference between the lower limit of the threshold and the tension deviation value) is calculated, and the first adjustment coefficient is determined according to the preset functional relationship (such as a linear function or a piecewise function). For example, the first adjustment coefficient can gradually decrease as the first difference increases, but remain between 0 and 1. Then, the current running speed is multiplied by the first adjustment coefficient to obtain the new running speed. When the tension deviation value is greater than the upper limit of the threshold, the second difference (i.e., the difference between the tension deviation value and the upper limit of the threshold) is calculated, and the second adjustment coefficient is determined according to the positive correlation relationship. For example, a linear growth or limited growth method is used to keep it between 1 and 1.5. Then, the current running speed is multiplied by the second adjustment coefficient to obtain the adjusted running speed, thereby realizing dynamic regression control of tension.

[0053] Furthermore, the setting of the first and second adjustment coefficients can be determined based on the tension response characteristics in actual production. The optimal speed adjustment ratio corresponding to different tension deviations can be obtained through experiments, and the functional relationship between the adjustment coefficient and the difference can be fitted. For example, a linear function, a piecewise linear function, or an exponential function can be used to characterize the relationship between the two. At the same time, reasonable upper and lower limit constraints should be set (such as the lower limit of the first adjustment coefficient being close to 0 but not 0, and the upper limit of the second adjustment coefficient not exceeding 1.5) to prevent over-adjustment. In practical applications, the function parameters can also be dynamically adjusted according to the strip thickness, material, or equipment inertia so that the adjustment coefficient can better match different working conditions, thereby achieving a stable and efficient tension control effect.

[0054] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0055] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0056] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0057] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for adaptive tension adjustment during the stretching process of PET strapping, characterized in that, include: Collect water temperature parameters and strip parameters of the heating and stretching device in the PET strapping production line; wherein, the strip parameters include strip tension value, strip thickness and strip running speed; The heating state of the strip is evaluated based on the water temperature parameters, and the degree of softening of the strip is determined in combination with the strip thickness. The strip state is then classified according to the degree of softening. The strip state includes under-softened state, moderately softened state, and over-softened state. When the strip is in a state of under-softening or over-softening, the water temperature parameter is adjusted to bring the strip to a state of moderate softening. When the strip is in a moderately softened state, the tension deviation between the strip tension value and the preset tension value is calculated. Based on the tension deviation value, it is determined whether the strip running speed should be adjusted. If it is determined that adjustment is needed, the strip running speed is adjusted according to the tension deviation value.

2. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 1, characterized in that, After collecting the water temperature parameters and strip material parameters of the heating and stretching device in the PET strapping production line, the water temperature parameters and strip material parameters are preprocessed, including: The collected water temperature and strip parameters are filtered. The units for strip thickness and strip running speed are standardized. The water temperature parameters and strip parameters are synchronously calibrated to ensure that the water temperature parameters and strip parameters correspond consistently in the time dimension.

3. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 2, characterized in that, The evaluation of the heating state of the strip based on the water temperature parameters includes: The synchronously corrected water temperature parameters are used as the characterization parameters of the heating temperature of the strip in the heating water tank. The residence time of the strip in the heating water tank is determined by combining the strip running speed, so as to characterize the heating time of the strip; Based on the characterization parameters of the heating temperature and the heating time, the degree of heating of the strip is determined, and the heating state of the strip is graded and evaluated according to the degree of heating sufficiency.

4. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 3, characterized in that, The step of determining the degree of heating sufficiency of the strip based on the characterization parameters of the heating temperature and the heating duration, and classifying and evaluating the heating state of the strip according to the degree of heating sufficiency, includes: The temperature characteristics of the heated material are compared with a preset temperature reference range to determine the temperature range in which the strip is located. The heating time is compared with the preset heating time range to determine whether the heating time of the strip meets the preset requirements. Based on the matching of the temperature range and the heating time, the degree of heating of the strip is comprehensively determined: when the characteristic parameter of the heating temperature is lower than the preset temperature reference range or the heating time is lower than the preset heating time range, it is determined to be insufficient heating; when the characteristic parameter of the heating temperature is within the preset temperature reference range and the heating time is within the preset heating time range, it is determined to be moderate heating; when the characteristic parameter of the heating temperature is higher than the preset temperature reference range or the heating time exceeds the preset heating time range, it is determined to be overheated.

5. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 4, characterized in that, When determining the degree of softening of the strip based on its thickness, the following are included: Set the thickness threshold; If the strip thickness is less than or equal to the thickness threshold and the heating level is moderate, the strip softening level is determined to be moderately softened; if the strip thickness is less than or equal to the thickness threshold and the heating level is excessive, the strip softening level is determined to be over-softened; if the strip thickness is less than or equal to the thickness threshold and the heating level is insufficient, the strip softening level is determined to be under-softened. If the strip thickness is greater than the thickness threshold and the heating level is moderate, the strip softening level is determined to be under-softened; if the strip thickness is greater than the thickness threshold and the heating level is excessive, the strip softening level is determined to be moderately softened; if the strip thickness is greater than the thickness threshold and the heating level is insufficient, the strip softening level is determined to be under-softened.

6. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 5, characterized in that, The process of classifying the strip state according to its softening degree includes: When the strip softening degree is under-softened, the strip state is classified as under-softened state; When the strip softening degree is moderately softened, the strip condition is classified as moderately softened. When the strip softening degree is over-softened, the strip condition is classified as over-softened.

7. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 1, characterized in that, When the strip is in a state of under-softening or over-softening, adjusting the water temperature parameter to bring the strip to a state of moderate softening includes: When the strip is in a sub-softened state, the heating unit of the heating and stretching device is controlled to gradually increase the water temperature at a preset heating rate; when the strip is in a super-softened state, the heating unit is controlled to gradually decrease the water temperature at a preset cooling rate. During the adjustment of water temperature parameters, strip parameters are continuously collected and the degree of strip softening is judged in real time; when the degree of strip softening reaches the appropriate level, the adjustment of water temperature parameters is stopped and the current water temperature is maintained.

8. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 1, characterized in that, When the strip is in a moderately softened state, the calculation of the tension deviation between the strip tension value and the preset tension value includes: The tension deviation value is the difference between the strip tension value and the preset tension value.

9. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 1, characterized in that, When determining whether to adjust the strip running speed based on the tension deviation value, the following steps are included: Set the deviation threshold range; If the tension deviation value is within the deviation threshold range, it is determined that the strip running speed will not be adjusted. If the tension deviation value is not within the deviation threshold range, it is determined that the strip running speed should be adjusted.

10. The method for adaptive tension adjustment during the stretching process of PET strapping according to claim 9, characterized in that, When adjusting the strip running speed according to the tension deviation value, the following steps are included: When the tension deviation value is less than the minimum value of the deviation threshold range, the difference between the minimum value of the deviation threshold range and the tension deviation value is calculated and recorded as the first difference; the strip running speed is adjusted by setting a first adjustment coefficient according to the first difference; wherein, 1 > first adjustment coefficient > 0, and the first adjustment coefficient is inversely proportional to the first difference, and the adjusted strip running speed is the product of the strip running speed before adjustment and the first adjustment coefficient; When the tension deviation value is greater than the maximum value of the deviation threshold range, the difference between the tension deviation value and the maximum value of the deviation threshold range is calculated and recorded as the second difference value; the second adjustment coefficient is set according to the second difference value to adjust the strip running speed; wherein, 1 < second adjustment coefficient < 1.5, and the second adjustment coefficient is proportional to the second difference value, and the adjusted strip running speed is the product of the strip running speed before adjustment and the second adjustment coefficient.

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