Injection molding process control method and system of injection molding machine for tableware preparation

Abstract

The invention discloses an injection molding process control method and system of an injection molding machine for tableware preparation, relates to the field of injection molding process control of injection molding machines for tableware preparation, and is used for improving the product percent of pass and production efficiency. The method comprises the steps that the screw melt pushing efficiency in the injection molding process, the flowing characteristics of plastic raw materials and the environment temperature around the injection molding machine are obtained; according to the screw melt pushing efficiency, the flowing characteristics of the plastic raw materials and the environment temperature, the safe operation range of injection molding parameters is dynamically adjusted; an injection molding parameter instruction is generated and executed according to the injection molding parameter safety operation range after dynamic adjustment; and in the process of executing the injection molding parameter instruction, the internal pressure of the mold is monitored in real time, local intervention is carried out according to the internal pressure of the mold, and the local intervention comprises reduction of the injection molding speed or switching of pressure maintaining in advance.

Description

Technical Field

[0001] This invention relates to the field of injection molding process control for injection molding machines used in tableware preparation, and particularly to a method and system for controlling the injection molding process of such machines. Background Technology

[0002] Traditional injection molding methods typically rely on preset parameter tables and basic feedback mechanisms to manage melt filling. However, with long-term operation of the equipment, factors such as slight wear of key components like the injection molding machine screw can lead to uneven melt delivery efficiency, thereby affecting product quality.

[0003] During long-term continuous production operation, the injection molding machine screw, especially in the area near the nozzle, will inevitably wear, causing a slight decrease in its actual melt delivery efficiency at specific injection speed ranges. This is because wear alters the effective geometry of the screw, increasing the gap between the screw and the inner wall of the barrel, or weakening the screw's conveying capacity in localized areas. When the control system issues commands based on the "injection speed segment setting table," requiring the screw to advance at a specific speed, the actual melt flow rate entering the mold cavity will deviate slightly from the expected value due to the reduced melt delivery efficiency in the worn area. This means that although the screw position signal fed back by the control system may match the set value, the actual filling speed of the melt in the mold cavity will differ from the target value.

[0004] This slight deviation in filling speed caused by screw wear can lead to significant appearance quality issues in the production of highly transparent tableware. On the inner surface of the mold cavity for highly transparent tableware, this inconsistent melt flow manifests as slight, irregular flow marks in the translucent areas of the finished tableware. Furthermore, in areas with complex structures, such as the thin-walled region where the handle connects to the body, the convergence point of the melt front may form a barely noticeable weld line.

[0005] Faced with these sporadic and irregularly distributed surface defects, production line operators begin to spot problems during routine inspections. Because the root cause of these defects lies hidden in the microscopic wear of the screw, and their manifestations (flow marks, weld lines) are related to various injection molding parameters, operators struggle to accurately pinpoint the root cause. Lacking precise diagnostic tools, operators often rely on experience to manually fine-tune individual parameters in the "target setting value for plastic melting temperature" or the "numerical table of injection speed segments," attempting to eliminate the defects through trial-and-error adjustments. However, this experience-based adjustment, when the screw already exhibits localized wear, is often a stopgap measure, or even counterproductive. These repeated, contradictory adjustments further narrow the already constrained process window due to screw wear. Any minor external disturbance, such as slight fluctuations in melt flow characteristics between raw material batches or minor changes in the production workshop's ambient temperature, can lead to random shifts in the type and location of defects. This uncertainty has severely reduced product quality consistency, leading to a continuous increase in scrap rates and significantly impacting production efficiency and material utilization. In this complex situation, traditional injection molding process control methods, typically based on the assumptions of stable equipment hardware and predictable process parameter responses, are no longer effective. Summary of the Invention

[0006] This invention provides a method for controlling the injection molding process of an injection molding machine for tableware preparation. It aims to solve the problems of existing injection molding process control methods, which are difficult to accurately control melt delivery efficiency under the influence of factors such as long-term equipment operation, component wear and tear and changes in the external environment, resulting in decreased product quality, low production efficiency and repeated trial and error by operators.

[0007] In a first aspect, in order to solve the above-mentioned technical problems, the present invention provides a method for controlling the injection molding process of an injection molding machine for tableware preparation, including: obtaining the screw melt pushing efficiency, the flow characteristics of the plastic raw material and the ambient temperature around the injection molding machine during the injection molding process;

[0008] The safe operating range of injection molding parameters is dynamically adjusted based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature.

[0009] Based on the dynamically adjusted safe operating range of the injection molding parameters, generate and execute injection molding parameter instructions;

[0010] During the execution of injection molding parameter instructions, the internal pressure of the mold is monitored in real time, and local interventions are made based on the internal pressure of the mold. Local interventions include reducing the injection speed or switching the holding pressure in advance.

[0011] This technical solution enables dynamic adjustment of injection molding parameters to address various uncertainties such as screw wear, changes in raw material properties, and fluctuations in ambient temperature. This effectively solves the problems of unstable product quality and high scrap rate under complex working conditions caused by traditional injection molding control methods, and significantly improves production efficiency and product qualification rate.

[0012] Furthermore, in some implementations, the injection parameters are an upper limit for injection speed, a lower limit for melt temperature, and a lower limit for cooling time.

[0013] This technical solution clarifies the specific types of injection molding parameters, providing specific targets for subsequent dynamic adjustments and making the control method more operable and targeted.

[0014] More specifically, when the injection parameters are at the upper limit of the injection speed, the safe operating range of the injection parameters is dynamically adjusted based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature, including:

[0015] Determine the screw efficiency loss ratio;

[0016] When the screw efficiency loss ratio is greater than or equal to the loss threshold, the upper limit of the injection speed is adjusted according to the upper limit adjustment formula.

[0017] The formula for adjusting the upper limit of injection speed is:

[0018] V2 = V1 × (1 + K1 × E);

[0019] Where V2 is the adjusted upper limit of injection speed, V1 is the upper limit of injection speed before adjustment, K1 is the preset first compensation coefficient, and E is the screw efficiency loss ratio.

[0020] This technical solution addresses the issue of reduced melt delivery efficiency caused by screw wear. By quantifying the proportion of screw efficiency loss and dynamically increasing the upper limit of injection speed according to an adjustment formula, it compensates for insufficient actual filling speed caused by wear, ensuring the accuracy and consistency of melt filling and effectively avoiding defects such as flow marks and weld lines.

[0021] Preferably, determining the screw efficiency loss ratio includes:

[0022] Determine the screw efficiency loss ratio based on the screw efficiency loss ratio formula;

[0023] The formula for the screw efficiency loss ratio is:

[0024] E=(P_j-P_s) / P_j;

[0025] Where P_j represents the reference pressure of the molten plastic when it is pushed; P_s represents the actual pressure of the molten plastic when it is pushed.

[0026] This technical solution enables precise quantification of screw efficiency loss through pressure difference, providing a reliable basis for adjusting the upper limit of injection speed and further improving control accuracy.

[0027] Based on the above, this application further proposes that, when the injection molding parameters are at the lower limit of the melt temperature, the safe operating range of the injection molding parameters can be dynamically adjusted according to the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature, including:

[0028] Determine the melt flow index value corresponding to the flow characteristics of the plastic raw material;

[0029] If the melt flow index value is less than the melt flow index threshold, adjust the lower limit of the melt temperature according to the formula for adjusting the lower limit of the melt temperature;

[0030] The formula for adjusting the lower limit of the melting temperature is:

[0031] T2 = T1 + K_MFI × (MFI_b - MFI_s);

[0032] Where T2 represents the adjusted lower limit of the melting temperature, T1 represents the lower limit of the melting temperature before adjustment, K_MFI represents the preset second compensation coefficient, MFI_b represents the standard melt flow index value, and MFI_s represents the actual melt flow index value.

[0033] This technical solution addresses the problem caused by fluctuations in the flow characteristics of plastic raw materials by dynamically adjusting the lower limit of the melting temperature through the melt flow index value. This ensures that the melt flowability within the mold is always at its optimal level, avoiding uneven filling and product defects caused by insufficient flowability.

[0034] As a technological improvement, when the injection molding parameters are at the lower limit of the cooling time, the safe operating range of the injection molding parameters is dynamically adjusted based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature. This includes:

[0035] When the ambient temperature is higher than the temperature threshold, adjust the lower limit of the cooling time according to the formula for the lower limit of the cooling time.

[0036] The formula for the lower limit of cooldown time is:

[0037] t_4 = t_3 + K_t × (T_s - T_b);

[0038] Where t_4 represents the adjusted lower limit of the cooling time, t_3 represents the original lower limit of the cooling time, K_t represents the preset third compensation coefficient, T_s represents the actual ambient temperature, and T_b represents the standard ambient temperature.

[0039] This technical solution allows for dynamic adjustment of the lower limit of cooling time based on the impact of ambient temperature changes on cooling performance, ensuring that products receive adequate cooling under different ambient temperatures and preventing deformation or dimensional instability caused by insufficient cooling.

[0040] In one embodiment, the safe operating range of injection molding parameters is dynamically adjusted based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature, including:

[0041] A pressure sensor array is arranged circumferentially along the melt flow channel before the injection molding machine nozzle exit and mold inlet to obtain the radial pressure distribution of the melt.

[0042] Obtain the viscosity spectrum and shear thinning behavior curve of plastic raw materials under non-uniform shear conditions;

[0043] To obtain the transient temperature distribution and local thermal disturbance areas of the melt inside the injection molding machine barrel;

[0044] Based on the radial pressure distribution of the melt, viscosity spectrum, shear thinning behavior curve, transient temperature distribution, and local thermal disturbance region, calculate the viscosity heterogeneity index and temperature heterogeneity index.

[0045] When the viscosity heterogeneity index or temperature heterogeneity index exceeds the preset threshold, the ultrasonic transducer array in the melt flow channel between the injection molding machine nozzle and the mold inlet is activated.

[0046] Based on the viscosity heterogeneity index, ultrasonic vibration is applied to reduce local viscosity;

[0047] Based on the temperature heterogeneity index, ultrasonic vibrations are applied to increase the local temperature.

[0048] This technical solution enables precise control of the viscosity and temperature heterogeneity within the melt through multi-dimensional sensor data and ultrasonic intervention, effectively solving the problem of local non-uniformity that may occur in the melt flow channel and further improving product quality.

[0049] As a further improvement, the method also includes:

[0050] Determine the viscosity heterogeneity index based on the viscosity heterogeneity index formula;

[0051] I_η = σ_P / P_average × (1 + C_shear × (η_highshear - η_lowshear) / η_average);

[0052] Where I_η is the viscosity heterogeneity index, σ_P is the standard deviation of radial pressure, P_mean is the mean of radial pressure, C_shear is the shear sensitivity coefficient, η_high shear represents the maximum viscosity at different radial positions, η_low shear represents the minimum viscosity at different radial positions, and η_mean represents the average viscosity at different radial positions.

[0053] This technical solution enables the precise calculation of the viscosity heterogeneity index using an accurate formula, providing a quantitative basis for ultrasonic intervention and ensuring the accuracy and effectiveness of the intervention.

[0054] Based on the above, the method also includes:

[0055] Calculate the temperature standard deviation across the cross-section of the melt;

[0056] The standard deviation of temperature is used as an index of temperature heterogeneity.

[0057] This technical solution can intuitively reflect the uniformity of melt temperature through the temperature standard deviation, providing a simple and effective basis for judgment of ultrasonic intervention.

[0058] Secondly, this application also discloses an injection molding process control system for an injection molding machine used in tableware preparation, the system comprising:

[0059] The acquisition module is used to acquire the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature around the injection molding machine during the injection molding process.

[0060] The adjustment module is used to dynamically adjust the safe operating range of injection molding parameters based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature.

[0061] The processing module is used to generate and execute injection parameter instructions based on the dynamically adjusted safe operating range of injection parameters;

[0062] The intervention module is used to monitor the internal pressure of the mold in real time during the execution of injection parameter instructions, and to perform local intervention based on the internal pressure of the mold. Local intervention includes reducing the injection speed or switching the holding pressure in advance.

[0063] This technical solution provides a system for implementing the aforementioned control methods. Through modular design, it enables comprehensive and intelligent control of the injection molding process, effectively improving the level of production automation and product quality stability.

[0064] Beneficial effects

[0065] This application discloses a method for controlling the injection molding process of an injection molding machine for tableware production. By acquiring the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature around the injection molding machine during the injection molding process, and dynamically adjusting the safe operating range of injection parameters based on this real-time data, injection parameter commands are generated and executed. During execution, the method also monitors the internal pressure of the mold in real time and performs local interventions, including reducing the injection speed or switching to holding pressure earlier. This technical solution effectively solves the problems in existing technologies, such as uneven melt delivery efficiency, unstable product quality, and repeated trial and error by operators caused by factors such as screw wear, raw material batch fluctuations, and changes in ambient temperature. Through dynamic sensing and adaptive adjustment of key parameters, this application can ensure the accuracy and consistency of melt filling, significantly reducing appearance defects such as flow marks and weld lines in high-transparency tableware products, thereby improving product qualification rate and production efficiency, and avoiding the uncertainty and negative impact of traditional experience-based adjustments. Attached Figure Description

[0066] Figure 1 This is a schematic flowchart of an injection molding process control method for tableware preparation using an injection molding machine, provided in an embodiment of the present invention.

[0067] Figure 2 This is a schematic flowchart of another injection molding process control method for tableware preparation using an injection molding machine provided in this embodiment of the invention;

[0068] Figure 3 This is a schematic diagram of the injection molding process control system for an injection molding machine used in tableware preparation, provided in an embodiment of the present invention. Detailed Implementation

[0069] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0070] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0071] In modern industrial manufacturing, especially for high-transparency products such as tableware, precise control of the injection molding process is crucial. Traditional injection molding methods typically rely on preset parameter tables and basic feedback mechanisms to manage melt filling. However, with long-term equipment operation, minor wear on key components such as the injection molding machine screw, as well as various unpredictable external factors during production, can lead to uneven melt delivery efficiency, thus affecting product quality. When operators attempt to manually adjust based on experience, they often find themselves in a cycle of trial and error, which may even backfire, severely impacting production efficiency and product yield.

[0072] Therefore, the injection molding process control method for tableware preparation provided in this application will be described in detail and explained through the following specific embodiments.

[0073] In response, this application proposes a method for controlling the injection molding process of an injection molding machine for tableware preparation, comprising:

[0074] To obtain the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature around the injection molding machine during the injection molding process;

[0075] The safe operating range of injection molding parameters is dynamically adjusted based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature.

[0076] Based on the dynamically adjusted safe operating range of the injection molding parameters, generate and execute injection molding parameter instructions;

[0077] During the execution of injection molding parameter instructions, the internal pressure of the mold is monitored in real time, and local interventions are made based on the internal pressure of the mold. Local interventions include reducing the injection speed or switching the holding pressure in advance.

[0078] The injection molding process control method for tableware preparation proposed in this application aims to overcome the challenges posed by equipment wear, raw material fluctuations, and environmental changes in the traditional injection molding process through intelligent means.

[0079] Among them, "screw melt delivery efficiency" refers to the actual efficiency of the injection molding machine screw in pushing molten plastic into the mold cavity, which is directly related to the uniformity and stability of melt filling.

[0080] "Flow characteristics of plastic raw materials" covers the viscosity and shear thinning behavior of plastics in the molten state, which affect the flow resistance of the melt in the mold channel.

[0081] "The safe operating range of injection molding parameters" refers to the allowable fluctuation range of injection molding parameters (such as injection speed, melt temperature, cooling time, etc.) under the premise of ensuring product quality and equipment safety. By dynamically adjusting and monitoring these key parameters in real time, this method can effectively improve the stability of the injection molding process and product quality.

[0082] Reference Figure 1 This invention provides a method for controlling the injection molding process of an injection molding machine for tableware preparation, comprising the following steps:

[0083] S1 obtains the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature around the injection molding machine during the injection molding process.

[0084] Specifically, the screw melt delivery efficiency can be obtained by installing a pressure sensor at the front end of the screw to measure in real time the difference between the actual pressure and the reference pressure of the molten plastic during delivery. The flow characteristics of the plastic raw material can be obtained by periodically testing the melt flow index (MFI) of the raw material, or by monitoring the viscosity changes of the melt in real time using an online rheometer. The ambient temperature around the injection molding machine can be collected in real time by deploying temperature sensors near the injection molding machine.

[0085] S2. Adjust the safe operating range of injection molding parameters dynamically based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature.

[0086] Among them, the injection molding parameters are the upper limit of injection speed, the lower limit of melt temperature, and the lower limit of cooling time.

[0087] As one possible implementation, when a decrease in screw melt delivery efficiency is detected, the upper limit of the injection speed can be adjusted accordingly to compensate for the efficiency loss and ensure the stability of melt filling. When the flow characteristics of the plastic raw material change (such as a decrease in the melt flow index), the lower limit of the melt temperature can be adjusted to ensure good melt flowability. When the ambient temperature rises, the lower limit of the cooling time can be adjusted to ensure that the product is fully cooled and deformation is avoided. This dynamic adjustment mechanism enables the injection molding process to better adapt to various changing factors, thereby maintaining a stable production state.

[0088] It should be noted that the specific details of this step can be found in the following sections, and will not be repeated here.

[0089] S3. Generate and execute injection parameter instructions based on the dynamically adjusted safe operating range of injection parameters.

[0090] As one possible implementation, these instructions could be specific settings for parameters such as injection speed, melt temperature, holding pressure, and cooling time. For example, if the adjusted upper limit of the injection speed is a certain value, the generated injection parameter instructions will ensure that the actual injection speed does not exceed that upper limit. These instructions are sent to the injection molding machine's control system, which then drives the injection molding machine to perform the corresponding operations.

[0091] S4. During the execution of injection molding parameter instructions, monitor the internal pressure of the mold in real time and make local interventions based on the internal pressure of the mold.

[0092] Local interventions include reducing the injection speed or switching the holding pressure earlier.

[0093] As one possible approach, when the internal pressure of the mold reaches a preset pressure value, the following local intervention can be performed:

[0094] 1. Immediately reduce the currently executing injection speed command, for example, reduce the injection speed by a preset step size.

[0095] Second, immediately stop injection filling and enter the holding pressure stage in advance to avoid excessive pressure in local areas of the melt, thereby preventing the formation of flash.

[0096] The injection molding process control method for tableware preparation proposed in this application significantly improves the intelligence level of the injection molding process by introducing real-time sensing and dynamic adjustment of screw melt delivery efficiency, plastic raw material flow characteristics, and ambient temperature. Traditional methods often rely on preset parameters and empirical adjustments, which are difficult to cope with complex factors such as equipment wear, raw material batch differences, and environmental fluctuations, resulting in unstable product quality and high scrap rates. The core innovation of this method lies in its ability to intelligently adjust the safe operating range of injection molding parameters based on these real-time acquired dynamic data, thereby ensuring that the injection molding process always operates in an optimal state. For example, when the screw experiences slight wear due to long-term operation, leading to a decrease in melt delivery efficiency, this method can automatically identify this change and adjust the upper limit of the injection speed accordingly to compensate for the efficiency loss, ensuring the stability and consistency of melt filling. In addition, by real-time monitoring of the internal pressure of the mold and local intervention, this method can promptly correct minor deviations in the filling process, effectively avoiding the generation of appearance defects such as flow marks and weld lines. This dynamic and adaptive control strategy not only improves product quality and production efficiency, but also reduces reliance on operator experience, providing a more reliable and efficient solution for the production of precision injection molded products such as highly transparent tableware.

[0097] Specifically, the aforementioned injection molding parameters can be understood as key process variables that need to be controlled and adjusted during the injection molding process. In this application, the injection molding parameters are specifically defined as the upper limit of injection speed, the lower limit of melt temperature, and the lower limit of cooling time.

[0098] The upper limit of injection speed refers to the maximum permissible speed at which molten plastic is injected into the mold cavity during the injection molding process. Setting this upper limit aims to prevent excessive shear heat, plastic degradation, or product defects caused by excessive speed, while ensuring filling efficiency. The lower limit of melt temperature refers to the minimum temperature that the plastic raw material must reach when heated and melted in the barrel. Setting this lower limit ensures sufficient fluidity of the plastic to smoothly fill the mold, avoiding problems such as underfilling and poor surface gloss, while also preventing excessively high melt viscosity due to low temperature, which increases screw pushing resistance. The lower limit of cooling time refers to the minimum time required for the product to cool and solidify within the mold after injection molding. Setting this lower limit ensures that the product has sufficient strength and rigidity before demolding, preventing product deformation or damage, and optimizing the production cycle.

[0099] This application clarifies the specific types of injection molding parameters, enabling more precise and operable control of the injection molding process. When dynamically adjusting the safe operating range of injection molding parameters, the upper limit of injection speed, the lower limit of melt temperature, and the lower limit of cooling time can be adjusted specifically. For example, when the screw melt delivery efficiency decreases, it may be necessary to adjust the upper limit of injection speed to compensate for the efficiency loss; when the flow characteristics of the plastic raw material change, it may be necessary to adjust the lower limit of melt temperature to ensure good flowability; when the ambient temperature rises, it may be necessary to adjust the lower limit of cooling time to ensure sufficient product cooling. This specific parameter definition provides a clear basis for subsequent parameter adjustments and command execution, contributing to more precise injection molding process control.

[0100] In some embodiments described above, a safe operating range for dynamically adjusting injection molding parameters based on screw melt delivery efficiency, the flow characteristics of the plastic raw material, and ambient temperature is proposed. These injection molding parameters may include an upper limit for injection speed. However, in actual injection molding, the screw's melt delivery efficiency may be reduced due to wear, changes in raw material properties, or fluctuations in operating conditions, resulting in a discrepancy between the actual melt delivery volume and the expected volume. This, in turn, affects the stability of the injection filling and product quality. Failure to finely adjust for the actual loss of screw efficiency may lead to an unreasonable upper limit for injection speed, failing to effectively compensate for efficiency losses, and potentially causing under-filling or product defects.

[0101] In this regard, such as Figure 2As shown, when the injection parameters are at the upper limit of the injection speed, the safe operating range of the injection parameters is dynamically adjusted according to the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature. This application may also include the following steps:

[0102] S101. Determine the screw efficiency loss ratio.

[0103] Specifically, the screw efficiency loss ratio is determined according to the screw efficiency loss ratio formula;

[0104] The formula for the screw efficiency loss ratio is:

[0105] E=(P_j-P_s) / P_j;

[0106] Where P_j represents the reference pressure of the molten plastic when it is pushed; P_s represents the actual pressure of the molten plastic when it is pushed.

[0107] Specifically, the screw efficiency loss ratio E refers to the difference between the actual and ideal pushing efficiency of the screw during the process of pushing molten plastic, caused by various factors (such as screw wear, barrel inner wall friction, and changes in melt viscosity). This ratio is quantified by pressure difference. P_j can be understood as the theoretical or reference pressure that the molten plastic should reach when pushed by the screw under ideal conditions, which can be obtained through pre-calibration or calculation based on standard process parameters. P_s can be understood as the actual pressure of the molten plastic being pushed, monitored in real time by a pressure sensor installed near the barrel or nozzle during actual injection molding. By comparing the difference between the reference pressure P_j and the actual pressure P_s, the efficiency loss of the screw pushing the melt can be accurately reflected.

[0108] This allows for precise quantification of the loss in screw melt delivery efficiency, avoiding the subjectivity and lag in traditional screw efficiency loss assessments. By monitoring the actual pressure P_s of the molten plastic in real time and comparing it with a reference pressure P_j, the screw efficiency loss ratio E can be accurately calculated. This precise quantification makes the adjustment of injection molding parameters more targeted and effective, thereby improving the stability of the injection molding process and product quality, while also extending the service life of the screw and barrel.

[0109] S102. When the screw efficiency loss ratio is greater than or equal to the loss threshold, adjust the upper limit of injection speed according to the upper limit adjustment formula.

[0110] The formula for adjusting the upper limit of injection speed is:

[0111] V2 = V1 × (1 + K1 × E);

[0112] Where V2 is the adjusted upper limit of injection speed, V1 is the upper limit of injection speed before adjustment, K1 is the preset first compensation coefficient, and E is the screw efficiency loss ratio.

[0113] Specifically, the screw efficiency loss ratio refers to the degree to which the actual pushing efficiency of an injection molding machine screw, when pushing molten plastic, decreases relative to the ideal or benchmark efficiency due to various factors (such as screw wear, barrel wall friction, and changes in raw material viscosity). This ratio can quantify the loss of screw pushing capacity, for example, by comparing the relationship between the number of screw revolutions and the actual melt discharge, or by monitoring the difference between screw back pressure and melt flow resistance. The loss threshold is a preset critical value used to determine whether the screw efficiency loss has reached a level requiring compensation adjustment. This threshold can be set based on empirical data, experimental results, or the injection molding precision requirements of a specific product to ensure that the upper limit adjustment of the injection speed is triggered only when necessary.

[0114] This application's solution effectively compensates for the actual loss of screw melt delivery efficiency by introducing a screw efficiency loss ratio and dynamically adjusting the upper limit of injection speed based on this ratio. Specifically, when the screw efficiency loss ratio is determined and reaches or exceeds a preset loss threshold, it indicates that the screw's delivery capacity has significantly decreased. At this time, by increasing the upper limit of injection speed using the formula V2=V1×(1+K1×E), even if the screw's delivery efficiency decreases during actual injection, the actual melt filling rate can be maintained by increasing the nominal injection speed, thereby ensuring sufficient filling of the mold cavity. The introduction of the first compensation coefficient K1 allows the system to flexibly adjust the compensation level according to the specific characteristics of the plastic raw material, mold structure, and product quality requirements to achieve the best injection molding effect.

[0115] Through the above technical solution, this application enables more precise control of the injection molding process. Compared to dynamic adjustments based solely on general parameters, this solution directly and quantitatively compensates for the actual loss in screw melt delivery efficiency, avoiding problems such as under-molding, unstable product dimensions, or surface defects caused by decreased screw efficiency. This significantly improves the consistency of injection molded product quality, reduces scrap rates, extends the service life of the injection molding machine, and optimizes production efficiency.

[0116] In some preferred embodiments, it is assumed that during the tableware preparation process, after long-term operation, the screw melt delivery efficiency of an injection molding machine decreases. Through monitoring and calculation, the current screw efficiency loss ratio E is determined to be 0.05 (i.e., a 5% efficiency loss). Assume the initial upper limit of injection speed V1 is 100 mm / s, the preset first compensation coefficient K1 is 0.8, and the loss threshold is set to 0.03. Since 0.05 is greater than 0.03, the system will activate the adjustment mechanism. According to the upper limit of injection speed adjustment formula V2 = V1 × (1 + K1 × E), the adjusted upper limit of injection speed V2 will be calculated as: V2 = 100 × (1 + 0.8 × 0.05) = 100 × (1 + 0.04) = 104 mm / s. This means that to compensate for the 5% efficiency loss of the screw, the system increases the upper limit of injection speed from 100 mm / s to 104 mm / s. In this way, even if the actual pushing capacity of the screw decreases, the melt can be filled into the mold at a rate close to the original effective rate by increasing the command speed, thereby maintaining product quality and production efficiency.

[0117] In some embodiments described above, a safe operating range for dynamically adjusting injection molding parameters based on screw melt delivery efficiency, the flow characteristics of the plastic raw material, and ambient temperature is proposed. These injection molding parameters include the lower limit of the melt temperature. However, in actual injection molding, the flow characteristics of the plastic raw material significantly influence the setting of the lower limit of the melt temperature. Failure to fully consider specific changes in the material's flowability may result in excessively high or low melt viscosity, thereby affecting mold filling performance and product quality, and even causing product defects. Therefore, this application further proposes a method for dynamically adjusting the lower limit of the melt temperature to ensure that optimal injection molding conditions are maintained even when the flow characteristics of the plastic raw material change.

[0118] In response, when the injection molding parameters are at the lower limit of the melt temperature, the safe operating range of the injection molding parameters is dynamically adjusted based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature. This includes:

[0119] S201. Determine the melt flow index value corresponding to the flow characteristics of the plastic raw material.

[0120] Specifically, the flow characteristics of plastic raw materials refer to the ease with which the plastic flows in the molten state, and can usually be quantified by the melt flow index. The melt flow index measures the mass or volumetric flow rate of molten plastic through a standard mold orifice at a certain temperature and pressure; a higher value indicates better flowability. The melt flow index threshold is a preset reference value used to determine whether the flowability of the plastic raw material is lower than expected, thereby deciding whether to adjust the melting temperature.

[0121] S202. When the melt flow index value is less than the melt flow index threshold, adjust the lower limit of the melt temperature according to the lower limit adjustment formula.

[0122] The formula for adjusting the lower limit of the melting temperature is:

[0123] T2 = T1 + K_MFI × (MFI_b - MFI_s);

[0124] Where T2 represents the adjusted lower limit of the melting temperature, T1 represents the lower limit of the melting temperature before adjustment, K_MFI represents the preset second compensation coefficient, MFI_b represents the standard melt flow index value, and MFI_s represents the actual melt flow index value.

[0125] This application's solution acquires the melt flow index (MFI) value corresponding to the flow characteristics of the plastic raw material in real time and compares it with a preset MFI threshold to determine whether there is a deviation in the raw material's fluidity. When the actual MFI_s value is less than the standard MFI_b value, it indicates that the plastic raw material's fluidity is lower than expected. In this case, the lower limit of the melt temperature is increased using the formula T2=T1+K_MFI×(MFI_b-MFI_s). This adjustment mechanism effectively compensates for the increase in melt viscosity caused by the decrease in raw material fluidity, ensuring that the melt maintains a suitable flow state during injection molding, thereby avoiding poor filling or product defects caused by insufficient fluidity.

[0126] Through the above technical solutions, the injection molding process can dynamically adjust the lower limit of the melt temperature according to the actual flow characteristics of the plastic raw material, thereby effectively addressing flowability fluctuations caused by factors such as batch differences in raw materials, changes in storage conditions, or degradation. This not only significantly improves the uniformity and integrity of mold filling and reduces defects such as short shots and flash, but also optimizes the internal structure and mechanical properties of the product, enhancing the quality stability of the final product. Furthermore, precise temperature control helps reduce energy consumption, extend the service life of the injection molding machine and mold, and achieve more efficient and stable production.

[0127] In some preferred embodiments, assume that an injection molding machine for tableware preparation is using polypropylene (PP) raw material for production. Its standard melt flow index (MFI_b) is set to 20 g / 10 min, the initial melt temperature lower limit (T1) is set to 200°C, and the preset second compensation coefficient (K_MFI) is 0.5. During production, the system obtains the actual melt flow index (MFI_s) of 18 g / 10 min through online monitoring or sampling of new batches of raw material. Since MFI_s (18 g / 10 min) is less than MFI_b (20 g / 10 min), the system determines that the current raw material flowability is below the standard. At this time, according to the melt temperature lower limit adjustment formula T2 = T1 + K_MFI × (MFI_b - MFI_s), the adjusted melt temperature lower limit T2 is calculated as: T2 = 200 + 0.5 × (20 - 18) = 200 + 0.5 × 2 = 201°C. The system dynamically adjusts the lower limit of the melting temperature from 200°C to 201°C to compensate for the decrease in raw material fluidity, ensuring that the filling performance of the melt in the mold is not affected, thereby maintaining the stability of product quality and the reliability of the production process.

[0128] In some embodiments described above, the safe operating range of injection molding parameters is dynamically adjusted, including the adjustment of the lower limit of cooling time. However, in actual injection molding processes, when the ambient temperature around the injection molding machine rises significantly, conventional dynamic adjustment strategies may not adequately compensate for the decrease in cooling efficiency caused by the increased ambient temperature. This could lead to insufficient cooling of tableware products, prolonged molding cycles, or damage to product quality. Failure to address these issues could affect the stability and production efficiency of the injection molding process. Therefore, this application further proposes an optimized adjustment scheme for the lower limit of cooling time to ensure effective control of the cooling process even at high ambient temperatures. Specifically, when the ambient temperature exceeds a preset threshold, the lower limit of cooling time is adjusted according to a specific formula.

[0129] When the above injection molding parameters are the lower limit of the cooling time, the safe operating range for dynamically adjusting the injection molding parameters based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature includes:

[0130] S301. When the ambient temperature is greater than the temperature threshold, adjust the lower limit of the cooling time according to the formula for the lower limit of the cooling time.

[0131] The formula for the lower limit of cooldown time is:

[0132] t_4 = t_3 + K_t × (T_s - T_b);

[0133] Where t_4 represents the adjusted lower limit of the cooling time, t_3 represents the original lower limit of the cooling time, K_t represents the preset third compensation coefficient, T_s represents the actual ambient temperature, and T_b represents the standard ambient temperature.

[0134] This application's solution addresses the aforementioned problems by introducing specific judgments about ambient temperature and formula-based adjustments. Specifically, when the actual ambient temperature T_s exceeds a preset temperature threshold, it indicates an increase in the thermal load of the injection molding machine, potentially leading to a decrease in mold cooling efficiency. In this case, the lower limit of cooling time t_3 is compensatorily extended using the formula t_4 = t_3 + K_t × (T_s - T_b), resulting in the adjusted lower limit t_4. The preset third compensation coefficient K_t quantifies the increase in cooling time required per unit temperature rise, while the difference between the actual ambient temperature T_s and the standard ambient temperature T_b reflects the degree to which the current ambient temperature deviates from the standard value. This adjustment mechanism ensures that tableware products have sufficient time to cool within the mold when the ambient temperature is high, thus avoiding problems such as deformation, dimensional instability, or surface defects caused by insufficient cooling. It is precisely this dynamic and quantitative adjustment that enables the injection molding process to maintain a stable cooling effect under different ambient temperatures.

[0135] Through the above technical solution, this application can effectively address the adverse effects of rising ambient temperature around the injection molding machine on the cooling process. Compared to simply making conventional dynamic adjustments, this application achieves refined control of the cooling process by introducing an ambient temperature threshold judgment and a formula-based adjustment of the lower limit of cooling time. This not only ensures that tableware products can be adequately cooled in high-temperature environments, effectively avoiding problems such as decreased product quality and extended molding cycles, but also improves the adaptability and stability of the injection molding process, thereby enhancing overall production efficiency and product qualification rate.

[0136] In some preferred embodiments, assuming a tableware injection molding machine operates at a standard ambient temperature T_b of 25°C, its lower limit of cooling time t_3 is set to 10 seconds. When the actual ambient temperature T_s is monitored by a sensor to reach 35°C, this temperature exceeds a preset temperature threshold (e.g., set to 30°C). At this time, the system will activate the lower limit of cooling time adjustment mechanism. If the preset third compensation coefficient K_t is 0.5 seconds / °C, then according to the lower limit of cooling time adjustment formula t_4=t_3+K_t×(T_s-T_b), the adjusted lower limit of cooling time t_4 will be calculated as 10 + 0.5 × (35 - 25) = 10 + 0.5 × 10 = 10 + 5 = 15 seconds. Therefore, the injection molding machine will implement the new lower limit of cooling time of 15 seconds to ensure that the tableware products can still be sufficiently cooled at higher ambient temperatures, thereby ensuring product quality and production stability.

[0137] Traditional injection molding process control methods for tableware manufacturing, while dynamically adjusting injection parameters within a safe operating range based on screw melt delivery efficiency, plastic raw material flow characteristics, and ambient temperature, often struggle to fully capture and effectively address potential localized viscosity and temperature heterogeneity in the melt runner. This heterogeneity may stem from complex shearing processes, uneven heating or cooling, resulting in an inhomogeneous melt state before entering the mold cavity. For example, if the melt viscosity is significantly higher at a certain radial location in the runner than in other areas, or if there are localized "cold spots," these issues, if left unresolved, will directly affect the mold's filling uniformity, potentially leading to defects such as warping, shrinkage marks, dimensional instability, or internal stress concentration in the finished product. Without addressing these problems, the quality of the final tableware product will be difficult to guarantee, resulting in higher scrap rates and negatively impacting production efficiency and economic benefits.

[0138] In response, this application proposes a more refined method for dynamically adjusting the safe operating range of injection molding parameters. By introducing multi-dimensional real-time monitoring and local intervention mechanisms, it aims to effectively solve the heterogeneity problem of melt in the runner, thereby improving the stability of the injection molding process and product quality.

[0139] In some of the embodiments described above in this application, a safe operating range for dynamically adjusting injection molding parameters based on screw melt delivery efficiency, flow characteristics of plastic raw materials, and ambient temperature is proposed. However, in the process of implementation, the local viscosity and temperature heterogeneity of the melt in the flow channel may not be fully identified and effectively controlled, thereby affecting the quality and stability of the injection molded product.

[0140] In this regard, this application further proposes the aforementioned safe operating range for dynamically adjusting injection molding parameters based on screw melt delivery efficiency, plastic raw material flow characteristics, and ambient temperature, including:

[0141] S401. A pressure sensor array is arranged circumferentially along the melt flow channel before the injection molding machine nozzle outlet and mold inlet to obtain the radial pressure distribution of the melt.

[0142] Specifically, an array of pressure sensors is arranged circumferentially along the melt flow channel before the injection molding machine nozzle exit and mold inlet. The purpose is to obtain the radial pressure distribution of the melt across the flow channel cross-section in real time and with high accuracy. By simultaneously measuring pressure at different radial positions using multiple sensors, non-uniformities in the melt flow can be captured, such as localized pressure differences caused by friction, shear, or temperature gradients. This pressure data is a crucial input for assessing melt viscosity heterogeneity.

[0143] S402. Obtain the viscosity spectrum and shear thinning behavior curve of the plastic raw material under non-uniform shear conditions.

[0144] Obtaining the viscosity spectrum and shear thinning behavior curve of plastic raw materials under non-uniform shear conditions can be understood as establishing the viscosity characteristics of the plastic raw materials at different shear rates and temperatures through prior experiments or theoretical modeling. The viscosity spectrum describes the relationship between viscosity and shear rate, while the shear thinning behavior curve specifically reflects the trend of viscosity reduction under high shear. These data are fundamental to understanding and predicting the behavior of melts in complex flow channels, especially when there is uneven radial pressure distribution, and help to more accurately calculate viscosity heterogeneity.

[0145] S403. Obtain the transient temperature distribution and local thermal disturbance area of ​​the melt inside the injection molding machine barrel.

[0146] In practical applications, obtaining the transient temperature distribution and local thermal disturbance regions of the melt inside the injection molding machine barrel refers to monitoring the real-time temperature changes of the melt inside the barrel and in the flow channel using devices such as thermocouple arrays or infrared sensors. The transient temperature distribution reveals the temperature gradients that may occur in the melt during heating, shearing, and flow, while local thermal disturbance regions refer to areas of localized overheating or undercooling caused by shear heat, friction, or uneven heating. This temperature information is crucial for assessing melt temperature heterogeneity.

[0147] S404. Calculate the viscosity heterogeneity index and temperature heterogeneity index based on the radial pressure distribution of the melt, viscosity spectrum, shear thinning behavior curve, transient temperature distribution, and local thermal disturbance region.

[0148] Among them, the viscosity heterogeneity index is used to quantify the degree of viscosity non-uniformity of the melt across its cross-section, while the temperature heterogeneity index is used to quantify the degree of temperature non-uniformity. These indices are key indicators for comprehensively evaluating melt quality, and their calculation methods can be based on statistical principles, such as standard deviation, coefficient of variation, or specific models.

[0149] For example, the viscosity heterogeneity index can be determined based on the viscosity heterogeneity index formula;

[0150] I_η = σ_P / P_average × (1 + C_shear × (η_highshear - η_lowshear) / η_average);

[0151] Where I_η is the viscosity heterogeneity index, σ_P is the standard deviation of radial pressure, P_mean is the mean of radial pressure, C_shear is the shear sensitivity coefficient, η_high shear represents the maximum viscosity at different radial positions, η_low shear represents the minimum viscosity at different radial positions, and η_mean represents the average viscosity at different radial positions.

[0152] Furthermore, the temperature standard deviation across the melt cross-section is calculated; this temperature standard deviation is then used as a temperature heterogeneity index. This standard deviation quantifies the dispersion of the temperature distribution across the melt's cross-section. Specifically, a larger temperature standard deviation indicates a more uneven temperature distribution across the melt's cross-section, i.e., higher temperature heterogeneity. Using the temperature standard deviation directly as a temperature heterogeneity index aims to provide an intuitive and quantitative indicator for assessing the uniformity of the melt's temperature distribution.

[0153] Thus, by combining the statistical characteristics of the radial pressure distribution of the melt (such as the radial pressure standard deviation σ_P and the radial pressure mean P_average) with the viscosity differences reflected by the viscosity spectrum and shear thinning behavior curves of the plastic raw material under non-uniform shear conditions (such as η_high shear, η_low shear, and η_average, as well as the shear sensitivity coefficient C_shear), a viscosity heterogeneity index I_η is constructed. This calculation method can more comprehensively and accurately assess the viscosity uniformity of the melt in the flow channel. The difference in radial pressure distribution directly reflects the non-uniformity of melt flow resistance, while the viscosity difference term further quantifies the material's response under different shear conditions. Therefore, when the viscosity heterogeneity index I_η exceeds a preset threshold, it can accurately indicate the existence of significant viscosity non-uniformity in the melt, thus providing a reliable basis for activating the ultrasonic transducer array and applying ultrasonic vibration to reduce local viscosity.

[0154] S405. When the viscosity heterogeneity index or temperature heterogeneity index exceeds the preset threshold, activate the ultrasonic transducer array in the melt flow channel between the injection molding machine nozzle and the mold inlet.

[0155] The ultrasonic transducer array is strategically positioned within the melt flow channel and is activated when melt heterogeneity exceeds acceptable limits. The introduction of ultrasound can exert a localized effect on the melt, thereby altering its rheological and thermal properties.

[0156] S406. Based on the viscosity heterogeneity index, apply ultrasonic vibration to reduce local viscosity.

[0157] Among them, ultrasonic vibration can generate micro-shearing and cavitation effects, thereby effectively reducing the local viscosity of high viscosity regions, making it closer to the overall average viscosity, and improving the fluidity of the melt.

[0158] S407. Based on the temperature heterogeneity index, apply ultrasonic vibration to increase the local temperature.

[0159] When ultrasonic energy propagates in the melt, some of the energy is absorbed and converted into heat energy, thereby heating the local low-temperature area, raising its temperature, and making it more consistent with the temperature of the surrounding melt.

[0160] This application's solution introduces a multi-dimensional real-time monitoring mechanism to accurately capture the radial pressure distribution, transient temperature distribution, and local thermal disturbance regions of the melt in the flow channel. Combined with the inherent rheological properties of the plastic raw material (viscosity spectrum and shear thinning behavior curve), it calculates viscosity heterogeneity indices and temperature heterogeneity indices that quantify melt inhomogeneity. Because these indices can reflect the melt's inhomogeneity at the microscopic level in real time, this application overcomes the limitations of traditional macroscopic parameter adjustments. When these heterogeneity indices exceed preset safety thresholds, the system can promptly activate an array of ultrasonic transducers deployed in key flow channel areas. Ultrasonic vibrations are precisely applied to the melt, and their energy generates local shear and thermal effects. Regarding viscosity heterogeneity, the microscopic shearing effect of ultrasound can effectively reduce the viscosity of locally high-viscosity regions, improving their flowability; while regarding temperature heterogeneity, the absorption and conversion of ultrasonic energy can raise the temperature of locally low-temperature regions. This local, real-time intervention mechanism allows the melt to reach a more uniform viscosity and temperature state before entering the mold, thus effectively solving problems such as uneven filling and increased internal stress caused by melt heterogeneity in traditional methods.

[0161] Through the above technical solution, this application enables precise perception and proactive control of the melt state during injection molding. Compared to basic solutions that rely solely on adjustments to macroscopic parameters, this application, by real-time monitoring of microscopic information such as radial pressure distribution and transient temperature distribution of the melt, combined with viscosity spectra and shear thinning behavior curves, can accurately identify and quantify the viscosity and temperature heterogeneity of the melt in the runner. This precise heterogeneity assessment allows the system to selectively activate the ultrasonic transducer array and apply corresponding ultrasonic vibrations based on the specific heterogeneity type (viscosity or temperature), thereby reducing local viscosity or increasing local temperature. Consequently, the uniformity of the melt before entering the mold is significantly improved, effectively avoiding product defects caused by melt inhomogeneity, such as warpage, shrinkage marks, and dimensional instability, significantly improving the quality and consistency of tableware products, while reducing scrap rates and increasing production efficiency and economic benefits.

[0162] In some preferred embodiments, a specific example is given below. Suppose that during the tableware manufacturing process, an injection molding machine is injecting molten polypropylene into a mold. During injection molding, due to uneven heating of the barrel or uneven shearing action of the screw, localized areas of excessively high viscosity and localized areas of excessively low temperature occur in the flow channel between the nozzle exit and the mold inlet of the molten material.

[0163] At this time, an array of pressure sensors arranged circumferentially along the melt flow path before the injection molding machine nozzle exit and mold inlet acquires the radial pressure distribution of the melt in real time. Simultaneously, the system combines pre-measured viscosity spectra and shear thinning behavior curves of polypropylene under non-uniform shear conditions with data on the transient temperature distribution and local thermal disturbance regions of the melt inside the barrel. Based on this data, the control system calculates the current viscosity heterogeneity index and temperature heterogeneity index.

[0164] For example, if the calculated viscosity heterogeneity index is 0.15, while the preset viscosity heterogeneity threshold is 0.10, it indicates significant non-uniformity in the melt viscosity. Similarly, if the temperature heterogeneity index is 0.08, while the preset temperature heterogeneity threshold is 0.05, it indicates non-uniformity in the melt temperature. Since both indices exceed the preset thresholds, the system immediately activates the ultrasonic transducer array in the melt flow channel between the injection molding machine nozzle and the mold inlet.

[0165] like Figure 3 As shown in the figure, this invention also provides a control system for the injection molding process of an injection molding machine for tableware preparation. The system includes:

[0166] The acquisition module is used to acquire the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature around the injection molding machine during the injection molding process.

[0167] The adjustment module is used to dynamically adjust the safe operating range of injection molding parameters based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature.

[0168] The processing module is used to generate and execute injection parameter instructions based on the dynamically adjusted safe operating range of injection parameters;

[0169] The intervention module is used to monitor the internal pressure of the mold in real time during the execution of injection parameter instructions, and to perform local intervention based on the internal pressure of the mold. Local intervention includes reducing the injection speed or switching the holding pressure in advance.

[0170] This application also provides a computer-readable storage medium. All or part of the processes in the above method embodiments can be executed by a computer program instructing related hardware. This program can be stored in the computer-readable storage medium, and when executed, it can include the processes of the above method embodiments. The computer-readable storage medium can be an internal storage unit of the task execution device (including a data sending end and / or a data receiving end) of any of the foregoing embodiments, such as the hard disk or memory of the task execution device. The computer-readable storage medium can also be an external storage device of the terminal device, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the terminal device. Further, the computer-readable storage medium can include both the internal storage unit of the task execution device and an external storage device. The computer-readable storage medium is used to store the computer program and other programs and data required by the task execution device. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0171] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0172] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0173] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application.

Claims

1. A method for controlling the injection molding process of an injection molding machine for tableware preparation, characterized in that, include: To obtain the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature around the injection molding machine during the injection molding process; The safe operating range of injection molding parameters is dynamically adjusted based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature. Based on the dynamically adjusted safe operating range of the injection molding parameters, generate and execute injection molding parameter instructions; During the execution of the injection molding parameter instructions, the internal pressure of the mold is monitored in real time, and local intervention is performed based on the internal pressure of the mold. The local intervention includes reducing the injection speed or switching the holding pressure in advance.

2. The method for controlling the injection molding process of an injection molding machine for tableware preparation according to claim 1, characterized in that, The injection molding parameters are the upper limit of injection speed, the lower limit of melt temperature, and the lower limit of cooling time.

3. The method for controlling the injection molding process of an injection molding machine for tableware preparation according to claim 2, characterized in that, When the injection parameters are at the upper limit of the injection speed, the safe operating range of dynamically adjusting the injection parameters based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature includes: Determine the screw efficiency loss ratio; If the screw efficiency loss ratio is greater than or equal to the loss threshold, the upper limit of the injection speed is adjusted according to the upper limit adjustment formula. The formula for adjusting the upper limit of injection speed is: V2 = V1 × (1 + K1 × E); Wherein, V2 is the adjusted upper limit of the injection speed, V1 is the upper limit of the injection speed before adjustment, K1 is the preset first compensation coefficient, and E is the screw efficiency loss ratio.

4. The injection molding process control method for tableware preparation using an injection molding machine according to claim 3, characterized in that, Determine the screw efficiency loss ratio, including: The screw efficiency loss ratio is determined according to the screw efficiency loss ratio formula; The formula for the screw efficiency loss ratio is: E=(P_j-P_s) / P_j; Where P_j represents the reference pressure of the molten plastic when it is pushed; P_s represents the actual pressure of the molten plastic when it is pushed.

5. The injection molding process control method for tableware preparation using an injection molding machine according to claim 2, characterized in that, When the injection molding parameters are at the lower limit of the melt temperature, the safe operating range of dynamically adjusting the injection molding parameters based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature includes: Determine the melt flow index value corresponding to the flow characteristics of the plastic raw material; If the melt flow index value is less than the melt flow index threshold, the lower limit of the melt temperature is adjusted according to the lower limit adjustment formula of the melt temperature. The formula for adjusting the lower limit of the melting temperature is: T2 = T1 + K_MFI × (MFI_b - MFI_s); Where T2 represents the adjusted lower limit of the melting temperature, T1 represents the lower limit of the melting temperature before adjustment, K_MFI represents the preset second compensation coefficient, MFI_b represents the standard melt flow index value, and MFI_s represents the actual melt flow index value.

6. The method for controlling the injection molding process of an injection molding machine for tableware preparation according to claim 2, characterized in that, When the injection molding parameters are the lower limit of the cooling time, the safe operating range of dynamically adjusting the injection molding parameters according to the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature includes: When the ambient temperature is greater than the temperature threshold, the lower limit of the cooling time is adjusted according to the formula for the lower limit of the cooling time. The formula for the lower limit of the cooling time is: t_4 = t_3 + K_t × (T_s - T_b); Where t_4 represents the adjusted lower limit of the cooling time, t_3 represents the original lower limit of the cooling time, K_t represents the preset third compensation coefficient, T_s represents the actual ambient temperature, and T_b represents the standard ambient temperature.

7. The method for controlling the injection molding process of an injection molding machine for tableware preparation according to claim 1, characterized in that, The safe operating range for dynamically adjusting injection molding parameters based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature includes: A pressure sensor array is arranged circumferentially along the melt flow channel before the injection molding machine nozzle exit and mold inlet to obtain the radial pressure distribution of the melt. Obtain the viscosity spectrum and shear thinning behavior curve of plastic raw materials under non-uniform shear conditions; To obtain the transient temperature distribution and local thermal disturbance areas of the melt inside the injection molding machine barrel; Based on the radial pressure distribution of the melt, the viscosity spectrum, the shear thinning behavior curve, the transient temperature distribution, and the local thermal disturbance region, calculate the viscosity heterogeneity index and the temperature heterogeneity index. When the viscosity heterogeneity index or the temperature heterogeneity index exceeds a preset threshold, the ultrasonic transducer array in the melt flow channel between the injection molding machine nozzle and the mold inlet is activated. Based on the viscosity heterogeneity index, ultrasonic vibration is applied to reduce local viscosity; Based on the temperature heterogeneity index, ultrasonic vibration is applied to increase the local temperature.

8. The method for controlling the injection molding process of an injection molding machine for tableware preparation according to claim 7, characterized in that, The method further includes: The viscosity heterogeneity index is determined according to the viscosity heterogeneity index formula; I_η = σ_P / P_average × (1 + C_shear × (η_highshear - η_lowshear) / η_average); Wherein, I_η is the viscosity heterogeneity index, σ_P is the radial pressure standard deviation, P_average is the radial pressure mean, C_shear is the shear sensitivity coefficient, η_high shear represents the maximum viscosity at different radial positions, η_low shear represents the minimum viscosity at different radial positions, and η_average represents the average viscosity at different radial positions.

9. A method for controlling the injection molding process of an injection molding machine for tableware preparation according to claim 7, characterized in that, The method further includes: Calculate the temperature standard deviation across the cross-section of the melt; The temperature standard deviation is used as the temperature heterogeneity index.

10. A control system for the injection molding process of an injection molding machine for tableware preparation, characterized in that, The system includes: The acquisition module is used to acquire the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature around the injection molding machine during the injection molding process. The adjustment module is used to dynamically adjust the safe operating range of injection molding parameters based on the screw melt delivery efficiency, the flow characteristics of the plastic raw material, and the ambient temperature. The processing module is used to generate and execute injection parameter instructions based on the dynamically adjusted safe operating range of injection parameters; The intervention module is used to monitor the internal pressure of the mold in real time during the execution of the injection parameter instructions, and to perform local intervention based on the internal pressure of the mold. The local intervention includes reducing the injection speed or switching the holding pressure in advance.

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