Hot runner injection molding systems, injection molding methods and their applications in toy manufacturing

Abstract

This invention discloses a hot runner injection molding system, including a runner heating module, a real-time monitoring module, and a dynamic control module. The runner heating module heats the injection runner and includes multiple sets of heating units equidistantly distributed along the axial direction of the injection runner and a PID temperature control unit for controlling the heating. The real-time monitoring module monitors the melt volumetric flow rate and temperature flowing into the runner and includes a flow monitoring unit and a temperature monitoring unit located at the runner inlet. The dynamic control module controls and adjusts the heating power of the runner heating module in real time based on the melt volumetric flow rate and temperature. It includes a data processing unit and a control unit. The data processing unit calculates the heat and heating power required for the melt to pass through the runner based on the melt volumetric flow rate and temperature, and controls the PID temperature control unit to perform temperature control through the control unit. This invention can dynamically calculate and control the hot runner heating power by monitoring the melt flow rate and temperature in hot runner injection molding in real time.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, and more specifically, to hot runner injection molding systems, injection molding methods, and their applications in toy production. Background Technology

[0002] Traditional hot runner injection molding systems often employ control methods such as constant temperature control, fixed power heating, or PID feedback control, which have the following drawbacks:

[0003] 1. Response lag: Relying solely on outlet temperature feedback cannot compensate for heat loss during melt flow;

[0004] Second, low energy efficiency: Constant power heating is prone to overheating during low-speed injection molding, which can lead to material degradation.

[0005] 3. Insufficient accuracy: The impact of sudden changes in flow rate on melt residence time was not considered, resulting in large temperature fluctuations;

[0006] While existing technologies have proposed speed and temperature control for hot runner injection molding, they lack physical models, and parameter adjustments rely on experience, making it difficult to adapt to various materials and changing operating conditions. In view of this, the present invention provides a hot runner injection molding system, injection molding method, and its application in toy production to solve the problems of lagging temperature control and high energy consumption in traditional technologies. Summary of the Invention

[0007] To address the aforementioned technical problems, the present invention aims to provide a hot runner injection molding system, injection method, and its application in toy production. The present invention dynamically calculates and controls the power required for hot runner heating by real-time monitoring of melt flow and temperature during the hot runner injection molding process. When applied to plastic toy production, the runner heating power can be dynamically adjusted in real time according to different toy injection molds, effectively saving energy, reducing costs, and increasing efficiency.

[0008] To achieve the above objectives, the present invention provides a hot runner injection molding system, which includes:

[0009] The runner heating module heats the injection molding runner and includes multiple sets of heating units equidistantly distributed along the axial direction of the injection molding runner and a PID temperature control unit for controlling the heating.

[0010] The real-time monitoring module monitors the volumetric flow rate and temperature of the melt flowing into the flow channel, including a flow monitoring unit and a temperature monitoring unit located at the flow channel inlet;

[0011] The dynamic control module, based on the volumetric flow rate and temperature of the melt monitored by the real-time monitoring module, controls and adjusts the heating power of the flow channel heating module in real time. It includes a data processing unit and a control unit. The data processing unit calculates the heat and heating power required for the melt to pass through the flow channel according to the volumetric flow rate and temperature of the melt, and controls the PID temperature control unit to perform temperature control through the control unit.

[0012] Furthermore, in the technical solution of the present invention, the heating unit includes an embedded electric heating rod assembly, a high-frequency inverter induction heating assembly, and an oil circuit jacket hot oil circulation heating assembly.

[0013] Furthermore, in the technical solution of the present invention, the flow monitoring unit includes an electromagnetic flow meter, and the temperature monitoring unit includes an infrared thermometer.

[0014] Furthermore, in the technical solution of the present invention, the data processing unit calculates the heat and heating power required for the melt to pass through the flow channel based on the melt's volumetric flow rate and temperature, specifically including the following steps:

[0015] Step S1: Calculate the time required for the melt to pass through the flow channel based on the monitored melt volumetric flow rate, specifically expressed as the ratio of the flow channel volume to the melt volumetric flow rate: ,in, This represents the time required for the melt to pass through the flow channel. It is expressed as the geometric length of the flow channel. Expressed as the cross-sectional area of ​​the flow channel. Expressed as the volumetric flow rate of the melt;

[0016] Step S2: Based on the time required for the melt to pass through the flow channel and the temperature of the melt when it flows into the flow channel, calculate the heat compensation required for the melt to pass through the flow channel. Specifically, this includes compensation for the temperature rise caused by the drop in melt temperature and compensation for the heat loss generated by the melt passing through the flow channel. ,in, This is expressed as heat compensation. This is expressed as temperature rise compensation. This is represented as heat loss compensation;

[0017] Step S3: Compensation based on the calculated required heat The required heating power is calculated by combining the heating time, i.e., the time it takes for the melt to pass through the flow channel: ,in, This is expressed as heating power. This is expressed as heating efficiency. It is expressed as a safety factor to compensate for fluctuations in material parameters at different temperatures.

[0018] Furthermore, in the technical solution of the present invention, in step S2,

[0019] Temperature rise compensation The calculation is based on thermodynamic formulas, specifically expressed as:

[0020] ,in, Expressed as melt density, Expressed as melt volume, Expressed as specific heat capacity of melt. Expressed as the required temperature, This is expressed as the temperature at which the melt flows into the flow channel;

[0021] Heat loss compensation The calculation is based on Fourier's law of heat conduction, specifically expressed as:

[0022] ,in, Expressed as the thermal conductivity of the flow channel material, This is expressed as the total surface area of ​​the flow channel. This represents the external mold temperature.

[0023] In another aspect, the present invention provides a hot runner injection molding method, employing a hot runner injection molding system as described above, specifically including the following steps:

[0024] Step M1: Data Acquisition: Monitor the volumetric flow rate and temperature of the melt flowing into the flow channel using an electromagnetic flow meter and an infrared thermometer to obtain the volumetric flow rate of the melt. and the temperature when the melt flows into the flow channel ;

[0025] Step M2: Data Processing: Based on Melt Volumetric Flow Rate Calculate the time required for the melt to pass through the flow channel. Further, based on the time required for the melt to pass through the flow channel... and the temperature when the melt flows into the flow channel Calculate the heat compensation required for the melt to pass through the flow channel. That is, the melt flows through the channel The heat demand generated within a time period, including the heat demand due to temperature rise and the heat demand due to heat loss, is further compensated based on the calculated heat. Calculate and confirm the required heating power ;

[0026] Step M3: Real-time control: The PID temperature control unit is controlled by the control unit to control the temperature and adjust the heating power accordingly. .

[0027] Furthermore, the hot runner injection molding method described in this invention is used in the toy manufacturing process.

[0028] Effective Gain: In summary, this invention provides a hot runner injection molding system, injection molding method, and its application in toy production. The hot runner injection molding system includes a runner heating module, a real-time monitoring module, and a dynamic control module. The hot runner injection molding method monitors the melt volumetric flow rate and temperature during the hot runner injection process in real time. It calculates the time the melt spends in the runner based on the melt volumetric flow rate, allowing for advance calculation of heat compensation requirements. Furthermore, it calculates the required power for runner heating based on these requirements. This allows for adjustment of the runner heating power according to different production application environments. When applied to plastic toy production, the runner heating power can be dynamically adjusted in real time according to different toy injection molds, effectively saving energy and reducing costs while increasing efficiency.

[0029] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0030] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a hot runner injection molding system module according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a data processing unit according to an embodiment of the present invention;

[0033] Figure 3 This is a flowchart of a hot runner injection molding method according to an embodiment of the present invention. Detailed Implementation

[0034] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] The core of this invention is to provide a hot runner injection molding system, injection method, and its application in toy production. This invention dynamically calculates and controls the power required for hot runner heating by real-time monitoring of melt flow and temperature during the hot runner injection molding process. When applied to plastic toy production, the runner heating power can be dynamically adjusted in real time according to different toy injection molds, effectively saving energy, reducing costs, and increasing efficiency.

[0036] One embodiment of the present invention proposes a hot runner injection molding system. Figure 1 This is a schematic diagram of a hot runner injection molding system module according to an embodiment of the present invention, as shown below. Figure 1 As shown, in this embodiment, the hot runner injection molding system includes:

[0037] The runner heating module heats the injection molding runner and includes multiple sets of heating units equidistantly distributed along the axial direction of the injection molding runner and a PID temperature control unit for controlling the heating.

[0038] The real-time monitoring module monitors the volumetric flow rate and temperature of the melt flowing into the flow channel, including a flow monitoring unit and a temperature monitoring unit located at the flow channel inlet;

[0039] The dynamic control module, based on the volumetric flow rate and temperature of the melt monitored by the real-time monitoring module, controls and adjusts the heating power of the flow channel heating module in real time. It includes a data processing unit and a control unit. The data processing unit calculates the heat and heating power required for the melt to pass through the flow channel based on the volumetric flow rate and temperature of the melt, and controls the PID temperature control unit to perform temperature control through the control unit.

[0040] Specifically, in this embodiment, the heating unit includes an embedded electric heating rod assembly, a high-frequency inverter induction heating assembly, and an oil circuit jacket hot oil circulation heating assembly.

[0041] Specifically, in this embodiment, the flow monitoring unit includes an electromagnetic flow meter, and the temperature monitoring unit includes an infrared thermometer.

[0042] Specifically, Figure 2 This is a schematic diagram of a data processing unit according to an embodiment of the present invention, such as... Figure 2 As shown, in this embodiment, the data processing unit calculates the heat and heating power required for the melt to pass through the flow channel based on the melt's volumetric flow rate and temperature, specifically including the following steps:

[0043] Step S1: Calculate the time required for the melt to pass through the flow channel based on the monitored melt volumetric flow rate. This is specifically expressed as the ratio of the flow channel volume to the melt volumetric flow rate, based on the law of conservation of mass. ,in, This represents the time required for the melt to pass through the flow channel. It is expressed as the geometric length of the flow channel. Expressed as the cross-sectional area of ​​the flow channel, the geometric length of the flow channel and flow channel cross-sectional area The cross-sectional area of ​​the circular runner is obtained from the injection mold used in hot runner injection molding. It can also be calculated as: ,in Represented as the radius of the circular flow channel. Expressed as the volumetric flow rate of the melt;

[0044] Step S2: Based on the time required for the melt to pass through the flow channel and the temperature of the melt when it flows into the flow channel, calculate the heat compensation required for the melt to pass through the flow channel. Specifically, this includes compensation for the temperature rise caused by the drop in melt temperature and compensation for the heat loss generated by the melt passing through the flow channel. ,in, This is expressed as heat compensation. This is expressed as temperature rise compensation. This is represented as heat loss compensation;

[0045] Step S3: Compensation based on the calculated required heat The required heating power is calculated by combining the heating time, i.e., the time it takes for the melt to pass through the flow channel: ,in, This is expressed as heating power. The heating efficiency is expressed as follows: In this embodiment, the heating efficiency is... The value is 0.85. This is expressed as a safety factor to compensate for fluctuations in material parameters at different temperatures, i.e., heating power. Need time The total calories provided are used for heat compensation. The amount of heat, and take into account the actual energy conversion loss.

[0046] In step S2,

[0047] Temperature rise compensation The calculation is based on thermodynamic formulas melt mass Substituting, specifically:

[0048] ,in, Expressed as melt density, Expressed as melt volume, Expressed as specific heat capacity of melt. Expressed as the required temperature, This is expressed as the temperature at which the melt flows into the flow channel;

[0049] Heat loss compensation The calculation is based on Fourier's law of heat conduction. In this embodiment, the heat transfer is simplified to steady-state heat transfer through the flow channel wall. In actual production, the flow channel wall thickness is usually greater than 5mm, at which point the side thermal resistance of the mold accounts for more than 90%. This simplification is reasonable and can be specifically expressed as follows:

[0050] ,in, Expressed as thermal conductivity of the flow channel material and flow channel wall thickness merge into middle, The total surface area of ​​the flow channel is expressed as the total surface area of ​​the circular flow channel. The calculation is as follows: ,in Indicated as the flow channel diameter, This represents the external mold temperature.

[0051] Specifically, based on the steps described above, this embodiment provides a specific application scenario: a hot runner (circular runner) injection molding process for PC material;

[0052] Basic parameters:

[0053] parameter Flow channel length Flow channel diameter melt density specific heat capacity of melt thermal conductivity initial temperature Demand temperature mold temperature Volumetric flow rate numerical values 300mm 8mm <![CDATA[1.2g / cm 3 ]]> 1.6J / gk 0.24W / mk 280℃ 320℃ 80℃ <![CDATA[150cm 3 / s]]>

[0054] Step S1: Calculate the time required for the melt to pass through the runner. :

[0055] ;

[0056] Step S2: Calculate the heat compensation required for the melt to pass through the flow channel. :

[0057] ;

[0058] ;

[0059] The injection flow rate is relatively fast, so the heat loss compensation is minimal;

[0060] ;

[0061] Step S3: Calculate the required heating power :

[0062] .

[0063] This embodiment also provides a hot runner injection molding method, employing a hot runner injection molding system as described above. Figure 3 This is a flowchart of a hot runner injection molding method according to an embodiment of the present invention, as follows: Figure 3 As shown, the specific steps include the following:

[0064] Step M1: Data Acquisition: Monitor the volumetric flow rate and temperature of the melt flowing into the flow channel using an electromagnetic flow meter and an infrared thermometer to obtain the volumetric flow rate of the melt. and the temperature when the melt flows into the flow channel ;

[0065] Step M2: Data Processing: Based on Melt Volumetric Flow Rate Calculate the time required for the melt to pass through the flow channel. Further, based on the time required for the melt to pass through the flow channel... and the temperature when the melt flows into the flow channel Calculate the heat compensation required for the melt to pass through the flow channel. That is, the melt flows through the channel The heat demand generated within a time period, including the heat demand due to temperature rise and the heat demand due to heat loss, is further compensated based on the calculated heat. Calculate and confirm the required heating power ;

[0066] Step M3: Real-time control: The PID temperature control unit is controlled by the control unit to control the temperature and adjust the heating power accordingly. .

[0067] One hot runner injection molding method of this embodiment is also used in the toy manufacturing process.

[0068] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot runner injection molding system, characterized in that, include: The runner heating module heats the injection molding runner and includes multiple sets of heating units equidistantly distributed along the axial direction of the injection molding runner and a PID temperature control unit for controlling the heating. The real-time monitoring module monitors the volumetric flow rate and temperature of the melt flowing into the flow channel, including a flow monitoring unit and a temperature monitoring unit located at the flow channel inlet; The dynamic control module, based on the melt volumetric flow rate and temperature monitored by the real-time monitoring module, controls and adjusts the heating power of the flow channel heating module in real time. It includes a data processing unit and a control unit. The data processing unit calculates the heat and heating power required for the melt to pass through the flow channel based on the melt volumetric flow rate and temperature, specifically including the following steps: Step S1: Calculate the time required for the melt to pass through the flow channel based on the monitored melt volumetric flow rate, specifically expressed as the ratio of the flow channel volume to the melt volumetric flow rate: ,in, This represents the time required for the melt to pass through the flow channel. It is expressed as the geometric length of the flow channel. Expressed as the cross-sectional area of ​​the flow channel. Expressed as the volumetric flow rate of the melt; Step S2: Based on the time required for the melt to pass through the flow channel and the temperature of the melt when it flows into the flow channel, calculate the heat compensation required for the melt to pass through the flow channel. Specifically, this includes compensation for the temperature rise caused by the drop in melt temperature and compensation for the heat loss caused by the melt passing through the flow channel. ,in, This is expressed as heat compensation. This is expressed as temperature rise compensation. This is represented as heat loss compensation; Temperature rise compensation The calculation is based on thermodynamic formulas, specifically expressed as: ,in, Expressed as melt density, Expressed as melt volume, Expressed as specific heat capacity of melt. Expressed as the required temperature, This is expressed as the temperature at which the melt flows into the flow channel; Heat loss compensation The calculation is based on Fourier's law of heat conduction, specifically expressed as: ,in, Expressed as the thermal conductivity of the flow channel material, This is expressed as the total surface area of ​​the flow channel. This is expressed as the external mold temperature; Step S3: Compensation based on the calculated required heat The required heating power is calculated by combining the heating time, i.e., the time it takes for the melt to pass through the flow channel: ,in, Expressed as heating power, This is expressed as heating efficiency. This is expressed as a safety factor to compensate for fluctuations in material parameters at different temperatures; The temperature is controlled by the PID temperature control unit through the control unit.

2. The hot runner injection molding system according to claim 1, characterized in that, The heating unit includes an embedded electric heating rod assembly, a high-frequency inverter induction heating assembly, and an oil circuit jacket hot oil circulation heating assembly.

3. A hot runner injection molding system according to claim 1, characterized in that, The flow monitoring unit includes an electromagnetic flow meter, and the temperature monitoring unit includes an infrared thermometer.

4. A hot runner injection molding method, characterized in that, The hot runner injection molding system according to any one of claims 1-3 specifically includes the following steps: Step M1: Data Acquisition: Monitor the volumetric flow rate and temperature of the melt flowing into the flow channel using an electromagnetic flow meter and an infrared thermometer to obtain the volumetric flow rate of the melt. and the temperature when the melt flows into the flow channel ; Step M2: Data Processing: Based on Melt Volumetric Flow Rate Calculate the time required for the melt to pass through the flow channel. Further, based on the time required for the melt to pass through the flow channel... and the temperature when the melt flows into the flow channel Calculate the heat compensation required for the melt to pass through the flow channel. That is, the melt passes through the flow channel The heat demand generated within a time period, including the heat demand due to temperature rise and the heat demand due to heat loss, is further compensated based on the calculated heat. Calculate and confirm the required heating power ; Step M3: Real-time control: The PID temperature control unit is controlled by the control unit to control the temperature and adjust the heating power accordingly. .

5. A hot runner injection molding method according to claim 4, used in toy manufacturing process.

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