Mold system and control method for injection molding of eco-friendly reinforced resin

Abstract

The present invention relates to an injection molding mold system and control method for eco-friendly reinforced resin injection, which prevents the problem of nozzle clogging or nozzle damage requiring nozzle replacement when temperature control around the nozzle and gate becomes difficult due to emergency or abnormal situations in the reinforced resin injection molding process, and suppresses the problem of molding instability and increased defects caused by the resin becoming excessively thin due to instantaneous overheating, thereby ensuring molding stability and reducing waste. The mold system of the present invention includes a heat transfer bushing, a cooling element and a heating element surrounding the outer surface thereof, a sensing unit based on multiple sensors, and a control unit that selectively controls cooling and heating based on temperature, temperature difference, and rate of change. By ensuring process stability even within the processing temperature range of the reinforced resin and reducing defects and rework, thereby reducing raw material usage and energy waste, the invention simultaneously achieves eco-friendliness at the material level through ensuring the durability of the reinforced resin product and reduces the environmental burden at the manufacturing process level.

Description

Technology Field

[0001] Embodiments of the present invention relate to injection molding mold technology, and more specifically, to an injection molding mold system and control method for eco-friendly reinforced resin injection, which contributes to reducing environmental burden by actively managing temperature fluctuations around the gate and nozzle in an injection molding process using reinforced resins such as glass fiber reinforced resin, carbon fiber reinforced resin, and mineral reinforced resin, thereby improving process stability and molding quality, and reducing molding defects and rework, and consequently reducing raw material waste and energy consumption. Background Technology

[0002] Recently, due to the spread of carbon neutrality and circular economy policies, stricter regulations on single-use plastics, and increasing ESG demands from companies, interest in materials and process technologies capable of reducing environmental burden is growing in the injection molding sector.

[0003] Against this backdrop, various types of reinforced resins, such as glass fiber reinforced resins (GF-PP, GF-PA, etc.), carbon fiber reinforced resins (CF-PA, CF-PPS, etc.), and mineral reinforced resins, are applied in diverse fields including automotive parts, electronic device housings, and industrial structural members due to their excellent mechanical strength, heat resistance, and dimensional stability. Products manufactured using reinforced resins exhibit significantly superior mechanical properties and durability compared to general-purpose resin products, extending their lifespan. Consequently, the replacement cycle is reduced, leading to a long-term decrease in resource consumption and waste generation. In this regard, reinforced resins possess eco-friendly value through resource conservation and waste reduction via extended product lifespans, and indeed, the number of eco-friendly certifications for products utilizing reinforced resins is increasing.

[0004] However, due to the addition of reinforcing materials (glass fibers, carbon fibers, mineral fillers, etc.), reinforced resins have higher melt viscosity and different flow characteristics compared to general-purpose resins (ABS, PP, PE, etc.). Furthermore, differences in thermal behavior between the reinforcing material and the matrix resin often result in a narrow processing temperature range or make thermal stability management difficult. These issues are not limited to resins with added reinforcing materials; highly transparent eco-resin such as PETG, Ecozen, and Tritan can experience yellowing or black spots even with slight overheating at the nozzle tip, leading to a significant deterioration in transparency and appearance quality. Additionally, recycled materials like recycled PET (R-PET) exhibit greater viscosity variations by grade compared to virgin materials and are prone to heat transfer imbalances caused by foreign substances, which can result in uneven filling balance across cavities. Consequently, applying these conditions in the same manner as conventional injection molding is prone to increasing process variability. For example, if localized overheating occurs around the nozzle and gate, thermal decomposition of the substrate resin is accelerated, leading to a decrease in viscosity, discoloration, and gas generation. This increases molding defects such as carbonization, silver streaks, and bubbles, resulting in waste and rework, and consequently becomes a factor that further increases the environmental burden. In particular, in the case of highly transparent eco-resins, if the resin remains inside the nozzle under abnormal conditions, yellowing or carbonization may occur due to even minute temperature deviations, causing appearance defects. Conversely, if localized overcooling occurs, gate freezing or flow channel blockage may lead to incomplete molding and filling imbalances, resulting in increased defect rates and reduced productivity, as well as accumulated unnecessary material and energy consumption.

[0005] In particular, while hot runner systems are advantageous for eco-friendly processes as they reduce material waste by minimizing runner scrap, inaccurate thermal management around the gate and nozzle can actually compromise the process stability of the reinforcing resin. The areas around the nozzle tip and gate are structurally thin and have low thermal capacity, making them sensitive to temperature fluctuations; consequently, the temperature can change rapidly in a short period of time due to power fluctuations or disturbances. This can lead to rapid solidification of the reinforcing resin or thermal decomposition of the base resin, resulting in nozzle clogging, component damage, and prolonged line stoppages. Consequently, this not only increases maintenance costs but also leads to reduced equipment operating efficiency, ultimately resulting in increased energy consumption and waste generation. Specifically, nozzle replacement due to nozzle tip damage results in significant inefficiency in terms of environmental burden, considering not only the resource consumption of the component itself but also the energy consumed for restarting the equipment (including preheating).

[0006] Furthermore, conventional mold temperature management often relies on single heating control centered on cooling water flow / temperature control or nozzle heaters. Consequently, it is difficult to rapidly restore the area around the gate to a target temperature in situations where overheating and undercooling occur alternately, and precise control considering temperature gradients (temperature differences) by location is limited. In particular, in multi-cavity or multi-point gate structures, temperature deviations between cavities can escalate into an imbalance in filling balance, making it more difficult to ensure the uniform quality required for reinforced resin injection products. This can consequently lead to an increase in defect rates and raw material consumption. These problems can be exacerbated when using recycled materials (such as R-PET). Since recycled materials exhibit larger viscosity variations by grade compared to new materials and are prone to heat transfer imbalances caused by foreign substances, it may be difficult to secure filling balance for each cavity using only conventional single heating control methods.

[0007] Meanwhile, to achieve substantial reduction in environmental burden in the reinforced resin injection molding process, technology is required that includes a structure for rapidly transferring and dispersing heat around the gate and nozzle, active temperature control means capable of rapid cooling in the event of overheating and rapid heating in the event of undercooling, and a technology that reduces defects and rework and minimizes energy and material waste by determining process conditions and performing control using temperature information from multiple locations. Through this, an injection molding technology is needed that can simultaneously achieve the eco-friendly benefits of extended product lifespan offered by reinforced resins and the effects of saving resources and energy in the manufacturing process. The problem to be solved

[0008] The present invention aims to solve various problems, including the problems mentioned above, and provides an injection molding mold system and control method for eco-friendly reinforced resin injection that can prevent the problem of nozzle clogging or nozzle damage caused by the rapid solidification of the resin at the tip of the nozzle, which necessitates replacing the nozzle itself, as temperature control around the nozzle and gate becomes difficult in emergency or abnormal situations such as power cutoff, sudden disturbance, or instantaneous over-output during the reinforced resin injection molding process.

[0009] In addition, the present invention aims to prevent gate freezing and flow path blockage caused by localized overcooling in emergency situations, while suppressing problems such as overfilling, viscosity instability, carbonization / discoloration that may occur when the resin becomes excessively thin due to instantaneous overheating, thereby ensuring molding stability even in a narrow processing temperature range of the reinforcing resin and reducing defects and waste.

[0010] Through this, the present invention aims to stably secure excellent mechanical properties and durability of reinforced resin products to achieve resource conservation effects through extended product lifespan, while simultaneously achieving reduction of environmental burden at the manufacturing process level, such as reduced nozzle replacement, reduced molding defects, and energy savings in the injection molding process.

[0011] However, these tasks are exemplary and do not limit the scope of the invention. means of solving the problem

[0012] A mold system for injection molding for eco-friendly reinforced resin injection according to one embodiment of the present invention may include: a manifold having a resin flow path formed therein for distributing molten resin injected from an injection machine; a nozzle device connected to the manifold and extending downward, having an internal flow path formed therein for guiding the molten resin distributed from the manifold to the gate of a cavity, and having a cross-section that narrows as it extends downward; a heat transfer bushing formed of a high thermal conductivity material having a higher thermal conductivity than mold steel, surrounding the lower part of the nozzle device; a cooling element arranged to surround the outer surface of the heat transfer bushing to cool the heat transfer bushing; a heating element arranged to surround the outer surface of the heat transfer bushing to heat the heat transfer bushing; a sensing unit for measuring the temperature around the nozzle device or the gate; and a control unit that receives temperature information from the sensing unit and controls the operation of the cooling element and the heating element based on the temperature information.

[0013] In one embodiment, the cooling element may be arranged to surround the upper outer surface of the heat transfer bushing, and the heating element may be arranged to surround the lower outer surface of the heat transfer bushing. In one embodiment, the cooling element may be a multi-stage Peltier element in which a plurality of thermoelectric modules are stacked.

[0014] In one embodiment, the sensing unit may include a plurality of temperature sensors each disposed at different locations within the mold, and the control unit may calculate a temperature difference based on temperature information measured from the plurality of temperature sensors, determine an overheated state or an overcooled state based on the temperature difference, and control the operation of the cooling element and the heating element based on the determination result. In one embodiment, the control unit may operate the cooling element when the temperature difference exceeds a preset upper threshold value, and operate the heating element when the temperature difference is less than a preset lower threshold value.

[0015] In one embodiment, the control unit may operate the cooling element when the rate of change of temperature over time measured by at least one of the plurality of temperature sensors exceeds a preset rate of increase threshold, and may operate the heating element when the rate of change is less than a preset rate of decrease threshold. In one embodiment, the control unit may calculate a control threshold corresponding to the rate of increase threshold and the rate of decrease threshold using the physical property value of the reinforcing resin, and may adjust the operating sensitivity of the cooling mode and the heating mode using an overheating reference time and an overcooling reference time that can be set by a user.

[0016] In one embodiment, the mold system may further include an emergency power supply unit that supplies power to the heating element independently of the main power supply, and the control unit may operate the heating element by receiving power from the emergency power supply unit when the interruption of the main power supply is detected.

[0017] In one embodiment, the heat transfer bushing may be formed of a beryllium copper alloy having a thermal conductivity of 80 W / m·K or higher.

[0018] In one embodiment, the wiring supplying power to the cooling element and the heating element can be drawn out of the mold along a wiring groove formed on the joint surface of the plate in which the heat transfer bushing is housed and an adjacent plate.

[0019] Meanwhile, a control method for an injection molding mold for eco-friendly reinforced resin injection according to one embodiment of the present invention may include the steps of: measuring the temperature around a nozzle device or a gate through a sensing unit; calculating a temperature difference or a rate of temperature change based on the measured temperature information by a control unit; determining an overheated state or an overcooled state based on the calculation result by the control unit; operating a cooling element by the control unit when an overheated state is determined; and operating a heating element by the control unit when an overcooled state is determined. In one embodiment, the method may further include the step of operating the heating element by receiving power from an emergency power unit when the control unit detects the cutoff of the main power supply. Effects of the invention

[0020] According to one embodiment of the present invention as described above, an injection molding mold system and control method for eco-friendly reinforced resin injection can be implemented, which prevents situations requiring nozzle replacement due to the rapid solidification of the resin at the tip of the nozzle, thereby blocking the flow path or damaging the nozzle by actively controlling the temperature around the nozzle and gate in emergency or abnormal situations. Furthermore, when injecting highly transparent eco-resins (PETG, Ecozen, Tritan, etc.), even if the resin remains inside the nozzle in abnormal situations, the temperature is immediately lowered through a cooling element to prevent yellowing and carbonization, thereby maintaining transparency and appearance quality. Of course, the scope of the present invention is not limited by these effects.

[0021] In addition, according to one embodiment of the present invention, molding instability (e.g., overfilling, burring, non-uniform viscosity, carbonization / discoloration) caused by the resin becoming excessively thin due to instantaneous overheating can be suppressed, thereby improving the stability of the reinforced resin injection molding process and reducing molding defects and rework. Accordingly, raw material waste and waste generation are reduced, and energy and resource consumption due to equipment stoppage and maintenance (such as nozzle replacement) is reduced, thereby contributing to the reduction of environmental burden at the manufacturing process level.

[0022] In addition, according to one embodiment of the present invention, resin solidification at the tip of the nozzle can be suppressed in emergency situations, thereby reducing nozzle replacement and prolonged equipment shutdown. Consequently, resource usage due to parts replacement and energy consumed for restarting the equipment (including preheating) can be reduced. Furthermore, molding defects and rework caused by overheating and overcooling are reduced, resulting in a decrease in raw material input and waste generation relative to the same production volume. Additionally, the runner waste reduction effect of the hot runner system can be stably realized in the reinforced resin process. Moreover, the adjustment of control threshold values ​​based on resin properties and user-set parameters facilitates the maintenance of an optimal process window for each material, thereby contributing to the reduction of environmental burden by simultaneously reducing defects and energy waste.

[0023] In addition, according to one embodiment of the present invention, the problem of viscosity instability occurring when using recycled materials (such as R-PET) can be resolved through active temperature control, thereby expanding the range of recycled materials available for adoption. Specifically, recycled materials such as R-PET exhibit large viscosity variations by grade compared to new materials and are prone to heat transfer imbalances caused by foreign substances; however, through real-time active temperature control by the heat transfer bushing (211), cooling element (214), and heating element (212) of the present invention, such irregular thermal flow is offset, thereby ensuring a filling balance for each cavity. In this way, the present invention can expand the range of environmentally friendly materials available for adoption by improving the process stability of recycled materials, which corresponds to environmental friendliness at the level of the manufacturing process.

[0024] Furthermore, since the reinforced resin product stably molded according to the present invention can secure excellent mechanical properties and durability, it can realize eco-friendly values ​​such as resource conservation and waste reduction through extended product lifespan. In other words, the present invention can simultaneously achieve eco-friendliness at the material level of the reinforced resin (resource conservation through improved product durability) and eco-friendliness at the manufacturing process level (reduced nozzle replacement, reduced molding defects, and energy savings). Brief explanation of the drawing

[0025] The above-described features of the present invention will be more clearly understood from the following detailed description of exemplary and non-limiting embodiments with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a hot runner system according to one embodiment of the present invention. Figure 2 is a cross-sectional view showing the nozzle device of Figure 1. FIG. 3 is a block diagram schematically showing a hot runner-based injection molding mold system according to one embodiment of the present invention. FIG. 4 is a flowchart illustrating a control method for a hot runner-based injection molding mold system according to one embodiment of the present invention. Specific details for implementing the invention

[0026] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0027] In describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description is omitted.

[0028] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0029] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0030] In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0031] In this specification, when various components such as layers, films, regions, and plates are described as being "on" another component, this includes not only cases where they are "directly on" another component, but also cases where other components are interposed between them.

[0032] In this specification, "upper" and "lower" are defined based on the nozzle axis direction shown in FIGS. 1 and 2, with the manifold (MF) side being the upper and the cavity (SP) and gate side being the lower. Additionally, "outer" refers to the radially outer side from the center axis in an axial structure in which the nozzle tip (210), heat transfer bushing (211), cooling element (214), and heating element (212) are arranged.

[0033] In this specification, "around the gate" refers to an area including an inlet where molten resin flows from the nozzle tip (210) into the cavity (SP), and may include, for example, a mold member near the gate and an adjacent area.

[0034] In this specification, "emergency situation" may include a situation in which the normal operating range is exceeded due to the interruption of the main power, power fluctuations, sudden heat loss, or sudden temperature changes. Additionally, "abnormal situation" or "disturbance" may include external factors affecting the temperature of the mold system, such as changes in cooling water conditions, changes in ambient temperature, instantaneous over-output, or changes in heat transfer paths.

[0035] In this specification, "reinforced resin" refers to a resin to which a reinforcing material, such as glass fiber, carbon fiber, or mineral filler, has been added to a matrix resin. Examples include, but are not limited to, glass fiber reinforced polypropylene (GF-PP), glass fiber reinforced polyamide (GF-PA), carbon fiber reinforced polyamide (CF-PA), carbon fiber reinforced polyphenylene sulfide (CF-PPS), and mineral reinforced polyamide.

[0036] In addition, the concept of reinforcing resin in this specification is not limited to resins with added reinforcing materials, and may further include resins that are sensitive to heat or have a narrow processing window, requiring precise temperature control, even without the addition of reinforcing materials. For example, high-transparency biomass-based materials such as PETG, Ecozen, and Tritan may have their appearance quality degraded due to yellowing or black spots caused by slight overheating at the nozzle tip, even without the addition of reinforcing materials. Additionally, recycled materials such as recycled PET (R-PET) may require precise temperature control because they have large viscosity variations by grade compared to virgin materials and are prone to heat transfer imbalances caused by foreign substances.

[0037] These materials share characteristics similar to resins with added reinforcing agents, such as a narrow processing temperature range or difficult thermal stability management, and are common in that process stability can be ensured by the active temperature control structure of the present invention. Since the addition of reinforcing agents improves mechanical strength, heat resistance, and dimensional stability, resulting in excellent product durability and a long lifespan, reinforced resins possess eco-friendly value in terms of resource conservation and waste reduction through a reduced product replacement cycle.

[0038] In this specification, the term "eco-friendly" is used to encompass the eco-friendliness of such reinforcing resins at the material level (resource conservation through extended product lifespan), contribution to the circular economy through the expanded application of recycled materials, and eco-friendliness at the manufacturing process level according to the present invention (reduction in nozzle replacement, reduction in molding defects, and reduction in environmental burden through energy savings).

[0039] FIG. 1 shows a cross-section of a hot runner system (10) according to one embodiment of the present invention.

[0040] The hot runner system (10) is a system that guides molten resin to the cavity of a mold in a heated state during the injection molding process. Since the resin in the runner portion does not solidify and remains in a molten state, runner scrap is not generated, thereby reducing material waste. The hot runner system (10) can be combined with the control unit (600), main power supply, and emergency power supply unit (700) described later to form the hot runner-based injection molding mold system (1) of the present invention.

[0041] As illustrated in FIG. 1, the hot runner system (10) can be configured by stacking and combining a top clamping plate (140), a spacer plate (130), a holding plate (120), and a cavity plate (110) from the top.

[0042] The top clamping plate (140) is positioned at the top of the hot runner system (10) and can perform the function of securing the mold to the fixed side platen of the injection machine. A locating ring into which the nozzle of the injection machine is inserted may be positioned on the top clamping plate (140), and the resin injection part (100) may pass through the top clamping plate (140) and be connected to the manifold (MF).

[0043] A spacer plate (130) is positioned between the top clamping plate (140) and the holding plate (120) to secure a space for accommodating a manifold (MF). By positioning the manifold (MF) within the space formed by the spacer plate (130), the thermal expansion of the manifold (MF) can be accommodated, and heat transfer to surrounding plates can be minimized.

[0044] The holding plate (120) is positioned between the spacer plate (130) and the cavity plate (110) and can perform the function of supporting and fixing the nozzle device (200, 200'). A nozzle receiving hole into which the nozzle device (200, 200') is inserted may be formed in the holding plate (120), and the nozzle device (200, 200') may be fixed in a fixed position by the holding plate (120) and aligned with the gate of the cavity (SP).

[0045] A cavity plate (110) is positioned at the bottom of a hot runner system (10) to form a cavity (SP) into which an injection-molded product is formed. A gate into which a nozzle tip (210) is inserted is formed in the cavity plate (110), so that molten resin discharged from a nozzle device (200, 200') can be filled into the cavity (SP). Additionally, a cooling water channel for cooling the molded product can be formed in the cavity plate (110).

[0046] A first cylinder device (300) and a second cylinder device (300') may be installed on the top clamping plate (140). The first cylinder device (300) may be positioned corresponding to the first nozzle device (200), and the second cylinder device (300') may be positioned corresponding to the second nozzle device (200'). The cylinder devices (300, 300') are driven by pneumatic or hydraulic pressure to apply pressure to the valve pin (240) inside each nozzle device (200, 200'), thereby moving the valve pin (240) up and down to control the opening and closing of the gate. Accordingly, the timing and amount of molten resin discharged through the nozzle tip (210) to the gate of the cavity (SP) can be controlled.

[0047] An air hole may be formed through the interior of the top clamping plate (140) in a horizontal direction. The air hole may function as an air passage to supply pneumatic pressure to the cylinder device (300, 300'), and compressed air supplied from an external pneumatic source may be transmitted to the cylinder device (300, 300') through the air hole. Additionally, the air hole may perform an air blow function to discharge residual gas or moisture inside the mold or to assist in demolding when ejecting the molded product. The opening and closing of the air hole may be controlled by a control unit (600), and the air hole control terminal (400) may be connected to a solenoid valve or pneumatic valve that performs the supply and blocking of air through the air hole according to a control signal from the control unit (600).

[0048] The electric control terminal (500) is an interface for electrical connection between the control unit (600) and the nozzle device (200, 200'), and can supply power and control signals from the control unit (600) to the second-1 heating unit (221), second-2 heating unit (231), cooling element (214), and heating element (212) of the nozzle device (200, 200'). Additionally, temperature information measured from the first temperature sensor (S1) to the fourth temperature sensor (S4) of the sensing unit can be transmitted to the control unit (600) through the electric control terminal (500). Accordingly, the control unit (600) can perform temperature control and monitoring of the hot runner system (10) through the electric control terminal (500).

[0049] A resin input section (100) into which molten resin is introduced from an injection molding machine may be disposed at the top, and a first heating section (101) for maintaining the temperature of the resin may be disposed at the resin input section (100) or in an adjacent area. The molten resin is introduced into a manifold (MF), distributed along an internal flow path (TL), and then supplied to each nozzle device (200, 200').

[0050] A plurality of nozzle devices (200, 200') extend downward from the manifold (MF) to guide the molten resin to the area around the gate of the cavity (SP), and a nozzle tip (210) is disposed at the bottom of each nozzle device (200, 200') to discharge the molten resin to the gate.

[0051] The hot runner system (10) of the present invention is configured to respond quickly to rapid overheating / undercooling situations occurring around the gate and nozzle tip (210) in order to ensure process stability of the reinforcing resin. In particular, since the area around the nozzle tip (210) has a small cross-section and low heat capacity, the resin may solidify rapidly when the power is cut off or a disturbance occurs. Therefore, the present invention provides a structure that can actively maintain or control the temperature around the nozzle tip (210), thereby reducing maintenance issues such as nozzle clogging and nozzle replacement. Accordingly, by reducing the consumption of parts resources and the energy required for equipment restart associated with nozzle replacement, the environmental burden of the manufacturing process is reduced, and at the same time, by ensuring molding stability, excellent physical properties and durability of the reinforcing resin product are secured, thereby contributing to resource conservation through the extension of product life.

[0052] As illustrated in FIG. 1, the sensing unit may include a first temperature sensor (S1) to a fourth temperature sensor (S4), and each temperature sensor may be positioned to measure the temperature at different locations within the hot runner system (10).

[0053] The first temperature sensor (S1) is positioned in the outer lower region of the heat transfer bushing (211), more specifically near the lower outer surface of the heat transfer bushing (211) adjacent to the end of the nozzle tip (210) and the gate, so as to measure the temperature around the nozzle tip (210) / gate. Accordingly, the first temperature sensor (S1) can represent the temperature condition of the region where the resin solidifies first in emergency situations, such as power cutoff or sudden heat loss, making it prone to flow path blockage or nozzle damage.

[0054] The second temperature sensor (S2) is positioned in the outer upper region of the heat transfer bushing (211), more specifically near the upper outer surface of the heat transfer bushing (211), so as to measure the temperature on the upper side of the heat transfer bushing (211). The first temperature sensor (S1) and the second temperature sensor (S2) may be positioned to correspond to the lower and upper parts of the heat transfer bushing (211), respectively, and the control unit (600) calculates the upper and lower temperature difference or temperature gradient of the heat transfer bushing (211) based on the temperature information obtained from them, and can use this to control the cooling element (214) and the heating element (212).

[0055] A third temperature sensor (S3) is positioned on the main body side of the nozzle device (200, 200'), for example, around the second-1 heating section (221) of the nozzle device (200, 200'), to measure the temperature of the main body of the nozzle device (200, 200'). A fourth temperature sensor (S4) is positioned around the resin input section (100) and / or the first heating section (101), to measure the temperature of the molten resin or surrounding material before and after it flows into the manifold (MF).

[0056] Additionally, the sensing unit may further include an external temperature sensor (not shown) for measuring the ambient temperature outside the hot runner-based injection molding mold system (1). The external temperature sensor (not shown) can measure the factory environment temperature outside the mold, that is, the atmosphere temperature of the workspace where the hot runner-based injection molding mold system (1) is installed, and may be placed, for example, on the outer surface of the mold, around the injection machine, or at a predetermined location within the workspace where the mold is installed. The external temperature Tamβ(t) measured by the external temperature sensor (not shown) is transmitted to the control unit (600) and can be used as a correction factor to reflect external environmental conditions when calculating the driving current of the heating element (212) described later.

[0057] In one embodiment, at least one of the plurality of temperature sensors may be inserted and disposed inside the heat transfer bushing (211). For example, a sensor insertion hole for inserting a temperature sensor may be formed in the heat transfer bushing (211), and the temperature sensor may be disposed within the sensor insertion hole to directly measure the internal temperature of the heat transfer bushing (211). As the temperature sensor is inserted and disposed inside the heat transfer bushing (211) in this manner, the actual temperature state around the nozzle tip (210) and the gate can be measured more accurately compared to when it is disposed on the outer surface of the heat transfer bushing (211), and this can contribute to improving the control precision of the cooling element (214) and the heating element (212).

[0058] FIG. 2 is a cross-sectional view showing a nozzle device (200, 200') included in the hot runner system (10) of FIG. 1.

[0059] As illustrated in FIG. 2, the nozzle device (200, 200') may include a main body portion having an internal flow path formed to guide molten resin distributed and supplied from a manifold (MF) to the gate of a cavity (SP), and a nozzle tip (210) disposed at the bottom of the main body portion to discharge the molten resin to the gate.

[0060] A nozzle passage through which molten resin flows may be formed inside the nozzle device (200, 200'). The nozzle passage may include a second nozzle passage (232) and a first nozzle passage (222). The second nozzle passage (232) is formed on the upper side of the nozzle device (200, 200') to receive molten resin supplied from the inlet (200in) of the manifold (MF), and the first nozzle passage (222) is formed to communicate with the lower part of the second nozzle passage (232) to guide the molten resin to the nozzle tip (210). That is, the molten resin is introduced into the nozzle device (200, 200') through the inlet (200in) of the manifold (MF), then moves downward from the second nozzle channel (232) to the first nozzle channel (222), and can be discharged to the gate of the cavity (SP) through the nozzle tip (210) attached to the bottom of the first nozzle channel (222).

[0061] A heating unit for heating the molten resin inside the nozzle passage may be disposed on the outer side of the nozzle device (200, 200'). The heating unit may include a second-1 heating unit (221) and a second-2 heating unit (231). The second-1 heating unit (221) may be disposed to surround the outer side of the first nozzle passage (222) to heat the molten resin inside the first nozzle passage (222), and the second-2 heating unit (231) may be disposed to surround the outer side of the second nozzle passage (232) to heat the molten resin inside the second nozzle passage (232). Accordingly, the molten resin flowing inside the nozzle device (200, 200') can be maintained at an appropriate temperature by the second-1 heating unit (221) and the second-2 heating unit (231), thereby preventing changes in viscosity or premature solidification.

[0062] Additionally, a valve pin (240) may be disposed inside the nozzle device (200, 200'). The valve pin (240) is configured to move up and down along the axial direction of the nozzle flow path, thereby selectively opening and closing the gate of the nozzle tip (210). When the valve pin (240) descends to close the gate, the discharge of molten resin is blocked, and when the valve pin (240) rises to open the gate, molten resin can be discharged into the cavity (SP). This valve gate method may be advantageous for preventing resin leakage when closing the gate and for minimizing gate marks on the molded product.

[0063] Additionally, a nozzle cover (230) for protecting or securing the nozzle device (200, 200') may be disposed on the outer side of the nozzle device (200, 200').

[0064] A heat transfer bushing (211) may be disposed on the outer side of the nozzle tip (210). The heat transfer bushing (211) may be formed of a high thermal conductivity material having a higher thermal conductivity than mold steel to enable rapid heat transfer in response to temperature fluctuations around the nozzle tip (210) and the gate. Accordingly, the heat transfer bushing (211) can function as a heat transfer medium that rapidly transmits the effects of the cooling and heating means described later to the nozzle tip (210) and the gate.

[0065] In one embodiment, the heat transfer bushing (211) may be formed from a beryllium copper alloy. The beryllium copper alloy may include specifications such as C17200 and C17500, and since it has a thermal conductivity of about 80 to 120 W / m·K, it can provide heat transfer performance that is about 3 to 4 times higher than the thermal conductivity of general mold steel, which is about 25 to 35 W / m·K. In another embodiment, the heat transfer bushing (211) may be formed from a high thermal conductivity mold steel such as Uddeholm Coolmould, in which case it may have a thermal conductivity of about 105 W / m·K. As the heat transfer bushing (211) is formed from a high thermal conductivity material, the thermal effect of the cooling element (214) and the heating element (212) can be rapidly transferred to the nozzle tip (210), and this provides a technical basis for the cooling element (214) and the heating element (212) to be simultaneously equipped in a single heat transfer bushing (211).

[0066] A cooling element (214) and a heating element (212) may be disposed on the outer surface of the heat transfer bushing (211). The cooling element (214) can cool the heat transfer bushing (211) to lower the temperature around the nozzle tip (210) and the gate, and the heating element (212) can heat the heat transfer bushing (211) to raise the temperature around the nozzle tip (210) and the gate. For example, the cooling element (214) may be implemented as a thermoelectric cooling means such as a Peltier element, and the heating element (212) may be implemented as a known electric heating means such as a cartridge heater, a band heater, or a thin film heater.

[0067] In one embodiment, the cooling element (214) may be a multi-stage Peltier element in which a plurality of thermoelectric modules are stacked. Since the multi-stage Peltier element can generate a larger temperature difference compared to a single Peltier element, it can provide effective cooling performance even inside a mold in a high-temperature environment.

[0068] Meanwhile, the insulating material (213) may be placed between the heating element (212) and the cooling element (214) to prevent the heating element (212) and the cooling element (214) from coming into direct contact. That is, the insulating material (213) prevents the heat from the heating element (212) from being transferred to the cooling element (214) and thereby reducing the cooling efficiency, or conversely, prevents the cooling effect of the cooling element (214) from affecting the heating element (212) and thereby reducing the heating efficiency, so that the cooling operation and the heating operation can be performed independently without interference with each other.

[0069] Additionally, the arrangement of the cooling element (214) and the heating element (212) can be varied in many ways. In one embodiment, the cooling element (214) may be arranged to surround the upper outer surface of the heat transfer bushing (211), and the heating element (212) may be arranged to surround the lower outer surface of the heat transfer bushing (211). In this case, the cooling element (214) is placed on the upper side where there is relatively more space to ensure heat dissipation and cooling efficiency, and the heating element (212) is placed on the lower side adjacent to the nozzle tip (210) to ensure a rapid heating response in abnormal situations.

[0070] FIG. 3 is a block diagram schematically showing a hot runner-based injection molding mold system (1) according to one embodiment of the present invention.

[0071] As illustrated in FIG. 3, a hot runner-based injection molding mold system (1) may include a hot runner system (10), a control unit (600), a main power supply, and an emergency power supply unit (700). As described above in FIG. 1 and FIG. 2, the hot runner system (10) may include a manifold (MF), a nozzle device (200, 200'), a nozzle tip (210), a heat transfer bushing (211), a cooling element (214), a heating element (212), a sensing unit, and a plurality of plates (110, 120, 130, 140). The control unit (600) receives temperature information from the sensing unit of the hot runner system (10) and can control the operation of the cooling element (214) and the heating element (212). The main power supply supplies power during normal operation of the hot runner-based injection molding mold system (1), and the emergency power supply unit (700) can supply emergency power to the heating element (212) when the main power supply is cut off.

[0072] A hot runner-based injection molding mold system (1) may include a control unit (600) that controls the operation of a cooling element (214) and a heating element (212) based on temperature information obtained from a sensing unit. The sensing unit may include one or more temperature sensors placed at least one location among a nozzle device (200, 200'), a location around a gate, or a location related to a heat transfer bushing (211), and in an embodiment where a plurality of temperature sensors are applied, a temperature difference and a rate of temperature change can be calculated from temperature information measured at different locations.

[0073] The control unit (600) selectively controls the operation of the cooling element (214) and the heating element (212) surrounding the heat transfer bushing (211) based on temperature information, temperature difference, or temperature change rate received from the sensing unit. For example, when an overheating state is detected, the control unit (600) can lower the temperature around the gate and nozzle tip (210) by operating the cooling element (214) to cool the heat transfer bushing (211), and when an overcooling state is detected, it can prevent the resin around the nozzle tip (210) from rapidly solidifying by operating the heating element (212) to heat the heat transfer bushing (211).

[0074] Additionally, the emergency power supply unit (700) of FIG. 3 can be configured to supply power to the heating element (212) independently of the main power supply. For example, when the main power supply is cut off, the control unit (600) receives power from the emergency power supply unit (700) and drives the heating element (212), thereby preventing a situation where the resin hardens first around the nozzle tip (210) with a small heat capacity, blocking the flow path or damaging the nozzle and requiring replacement.

[0075] In addition, in one embodiment, the wiring supplying power to the cooling element (214) and the heating element (212) can be drawn out of the mold along a wiring groove formed on the joint surface of the plate in which the heat transfer bushing (211) is housed and an adjacent plate, thereby reducing wiring interference and improving assembly and maintenance even under internal mold space constraints.

[0076] The control unit (600) can perform computation and control functions to control the operation of the cooling element (214) and the heating element (212) based on temperature information collected from the sensing unit within the hot runner-based injection molding mold system (1) of the present invention. According to one embodiment, the control unit (600) according to the present invention may include a processor, a memory, and a communication module.

[0077] The processor can execute instructions stored in memory to perform the overall operation of the control unit (600), process signals and data input from the sensing unit, and generate control signals for driving the cooling element (214) and the heating element (212). The memory can store data and instructions for the operation of the control unit (600). For example, the memory can store temperature data collected from the sensing unit, parameters for calculating the temperature difference and the rate of temperature change, operating thresholds for the cooling element (214) and the heating element (212), overheating reference time and undercooling reference time set by the user, and program code for executing a control algorithm.

[0078] The control unit (600) can obtain temperature information from each of the first temperature sensor (S1) to the fourth temperature sensor (S4) included in the sensing unit. The control unit (600) can store or update the temperature information obtained from each temperature sensor by sampling it in real time or periodically, and can control the operation of the cooling element (214) and the heating element (212) by determining the current thermal state of the hot runner-based injection molding mold system (1) based on the temperature information.

[0079] In one embodiment, the control unit (600) can calculate a change rate threshold value based on the physical property value of the reinforcing resin and user-set parameters, and thereby determine the operating mode of the cooling element (214) and the heating element (212). Here, since the thermal behavior of the reinforcing resin is mainly governed by the physical property of the base resin, the threshold value can be calculated based on the physical property value of the base resin. For example, the control unit (600) can apply the following operating mode determination logic.

[0080] [Mathematical Formula 1]

[0081] Operating Mode = { Cooling (if dT / dt > +θ h ), heating (if dT / dt < -θ c ), wait (otherwise)}

[0082] Here,

[0083] θ h = (Td - Tm) / t h

[0084] θ c = (Tm - Tg) / tc

[0085] And,

[0086] T is the measured temperature (unit: ℃),

[0087] t is time (unit: seconds),

[0088] dT / dt is the rate of change of the measured temperature over time (unit: ℃ / sec),

[0089] Td is the thermal decomposition temperature of the above reinforcing resin (unit: ℃),

[0090] Tm is the melting temperature of the above reinforcing resin (unit: ℃),

[0091] Tg is the glass transition temperature of the above reinforcing resin (unit: ℃),

[0092] t is the overheating threshold time set by the user (unit: seconds),

[0093] tc is the supercooling reference time set by the user (unit: seconds),

[0094] θ h is a temperature rise rate threshold (unit: ℃ / sec) for operating the cooling element (214),

[0095] θc is a temperature drop rate threshold (unit: ℃ / sec) for operating the heating element (212).

[0096] According to the above mathematical formula 1, the rate of increase of the measured temperature is θ h If it exceeds θc, the control unit (600) determines that it is in an overheated state and activates the cooling element (214), and if the rate of decrease of the measured temperature exceeds θc (i.e., dT / dt < -θc), the control unit (600) determines that it is in an overcooled state and activates the heating element (212). If the rate of increase and the rate of decrease are within their respective threshold ranges, the control unit (600) maintains a standby state.

[0097] The above threshold θ h and θc are calculated based on the thermal decomposition temperature (Td), melting temperature (Tm), and glass transition temperature (Tg), which are physical properties of the reinforcing resin, and the superheating reference time (t) and supercooling reference time (tc) set by the user. Accordingly, for reinforcing resins with a narrow processing temperature range, the threshold value is set to respond sensitively to small temperature changes, and for reinforcing resins with a wide processing temperature range, a more forgiving threshold value can be set.

[0098] For example, when injecting glass fiber reinforced polyamide 6 (GF-PA6) resin, the Td of the base resin PA6 may be approximately 350°C, Tm approximately 220°C, and Tg approximately 50°C. If the user sets t to 10 seconds and tc to 5 seconds, θ h = (350 - 220) / 10 = 13℃ / sec, and θc = (220 - 50) / 5 = 34℃ / sec. Therefore, when the temperature rise rate exceeds 13℃ / sec, the cooling element (214) operates, and when the temperature drop rate exceeds 34℃ / sec (i.e., dT / dt < -34℃ / sec), the heating element (212) operates.

[0099] Meanwhile, in the case of glass fiber reinforced polypropylene (GF-PP) resin, since the base resin PP has a Td of approximately 350°C, a Tm of approximately 165°C, and a Tg of approximately -10°C, θ at the same settings of t = 10 seconds and tc = 5 seconds h = (350 - 165) / 10 = 18.5℃ / sec, θ c = (165 - (-10)) / 5 = 35℃ / sec. This means that since GF-PP has a wider processing temperature window than GF-PA6, cooling / heating operates at a larger rate of temperature change.

[0100] Meanwhile, when injecting PETG resin, the thermal decomposition temperature (Td) of PETG may be approximately 300°C, the melting temperature (Tm) approximately 230°C, and the glass transition temperature (Tg) approximately 80°C. If the user sets t to 10 seconds and tc to 5 seconds, θ h = (300 - 230) / 10 = 7℃ / sec, and θc = (230 - 80) / 5 = 30℃ / sec is calculated. This is GF-PA6(θ h = 13℃ / sec) and GF-PP(θ h θ significantly smaller compared to = 18.5℃ / sec) h As a value, this means that the cooling element (214) operates sensitively even with a smaller temperature rise corresponding to the narrow processing temperature window (Td - Tm = 70℃) of PETG. Accordingly, yellowing and carbonization of highly transparent materials such as PETG can be effectively suppressed.

[0101] In addition, when injecting R-PET (recycled PET) resin, the Td of the base PET resin may be approximately 350°C, Tm approximately 250°C, and Tg approximately 75°C. However, since the actual thermal decomposition onset temperature of R-PET may be lower than that of virgin PET due to thermal history during the recycling process and the presence of impurities, the user may set Td conservatively (e.g., 320°C). In this case, θ at settings t = 10 seconds and tc = 5 seconds h = (320 - 250) / 10 = 7℃ / sec, θc = (250 - 75) / 5 = 35℃ / sec. Since R-PET has a large viscosity variation by grade and non-uniform flow characteristics, the control unit (600) monitors the temperature variation per cavity in real time based on temperature information obtained from a plurality of temperature sensors, and can secure a filling balance by individually controlling the cooling element (214) and the heating element (212).

[0102] The user t at the trial injection stage hBy adjusting and tc, the control sensitivity can be optimized to ensure quality while minimizing the operating frequency of the cooling element (214) and the heating element (212), thereby reducing unnecessary power consumption and improving energy efficiency. h If tc is set short, the threshold θ h and θ c As increases, control sensitivity decreases (insensitivity), and t h Setting tc to a long value reduces the threshold value, increasing the control sensitivity (sensitive).

[0103] Additionally, the control unit (600) can detect whether the main power is cut off, and if the main power is cut off and the temperature drop rate simultaneously exceeds a preset drop rate threshold, it can determine this as an overcooling state caused by the power cut-off. In this case, the control unit (600) receives power from the emergency power unit (700) and operates the heating element (212) first, thereby preventing the resin from rapidly solidifying around the nozzle tip (210) and causing nozzle clogging or nozzle damage.

[0104] In one embodiment, the control unit (600) can drive the heating element (212) through the emergency power unit (700) in an emergency situation where the main power cutoff is detected, but a thermal response delay may occur until the heating element (212) actually generates heat and affects the temperature around the nozzle tip (210) through the heat transfer bushing (211). Therefore, to compensate for the thermal response delay, the control unit (600) can calculate the intensity of the current applied to the heating element (212) based on the amount of change in the temperature difference between the sensors.

[0105] For example, the control unit (600) defines the temperature measured from the first temperature sensor (S1) as T1(t) and the temperature measured from the third temperature sensor (S3) as T3(t), and the temperature difference as △T 13(t) can be defined as (t) = T1(t) - T3(t). In addition, the control unit (600) defines the rate of change of the temperature difference over time as d(△T 13 It can be calculated as ) / dt. In this case, d(△T 13 Since the fact that ) / dt increases in the negative direction means that the location of the first temperature sensor (S1) (around the nozzle tip (210)) is cooling relatively faster than the location of the third temperature sensor (S3) (the nozzle body), the control unit (600) can detect this local overcooling progress early and preemptively increase the driving current of the heating element (212).

[0106] In one embodiment, the current I(t) applied to the heating element (212) can be determined by the following equation.

[0107] [Mathematical Formula 2]

[0108] I h (t) = sat( I h,0 + K(T amβ (t)) Х max(0, -d(△T 13 ) / dt) )

[0109] Here,

[0110] I h (t) is the current applied to the heating element (212) at time t (unit: A),

[0111] I h,0 is the basic current (unit: A),

[0112] sat() is I h (t) [I h,min , I h,max ] Saturation function that restricts to a range,

[0113] I h,min The minimum current (unit: A) applied to the heating element (212),

[0114] I h,max is the maximum current (unit: A) applied to the heating element (212),

[0115] max(a, b) is a function that returns the larger value between a and b,

[0116] T amβ (t) is an external temperature (unit: ℃) obtained from an external temperature sensor that measures the ambient temperature outside the hot runner-based injection molding mold system (1),

[0117] d(△T 13 ) / dt is the temperature difference △T 13 Rate of change of (t) over time (unit: ℃ / sec),

[0118] K(T amβ (t)) is a gain factor corrected according to the external temperature.

[0119] Also, K(T amβ (t)) can be defined as, for example, as follows.

[0120] [Mathematical Formula 3]

[0121] K(T amβ (t)) = K0× (1 + γ Х (T re f - T amβ (t)))

[0122] Here,

[0123] K0 is the reference gain (dimensionless),

[0124] T re f is the reference external temperature (unit: ℃),

[0125] γ is a correction coefficient (unit: 1 / ℃) that determines the sensitivity of the heating current correction according to external temperature changes, and can be preset by the user or the control unit (600).

[0126] Reference external temperature T re f is the external temperature T measured from the external temperature sensor (S5). re As the reference external temperature (unit: °C) for (t), the gain coefficient K(T amβ (t)) corresponds to a reference point where the correction amount becomes 0, and is a temperature of a standard working environment in which normal operation of the hot runner-based injection molding mold system (1) is performed, which is preset by the user or the control unit (600), and can be set, for example, to about 20°C to 25°C.

[0127] Therefore, the external temperature T amβ When (t) decreases (e.g., low-temperature winter environment), K(T amβ (t)) increases so that a larger heating current can be applied for the same supercooling rate, and conversely, unnecessary heating drive can be suppressed when the external temperature rises. Accordingly, the situation where the resin rapidly solidifies around the nozzle tip (210) and requires nozzle replacement is reduced, and at the same time, energy waste due to excessive heating is reduced, thereby contributing to the reduction of the environmental burden of the reinforced resin injection process.

[0128] FIG. 4 is a flowchart showing a control method for a hot runner-based injection molding mold system (1) according to one embodiment of the present invention.

[0129] Referring to FIG. 4, the control method may include a step (S100) of detecting whether the main power supply is cut off.

[0130] In the step (S100) of detecting whether the main power is cut off, the control unit (600) can monitor the status of the main power supplied to the mold system (1) for hot runner-based injection molding in real time. If the main power is cut off, the control unit (600) receives power from the emergency power unit (700) and operates the heating element (212) first, thereby preventing the resin from rapidly solidifying around the nozzle tip (210) with low heat capacity, which could block the flow path or damage the nozzle. If the main power is supplied normally, the process proceeds to the subsequent step.

[0131] The control method may include a step (S110) of measuring the temperature around the nozzle device (200, 200') or cavity gate through a sensing unit. The sensing unit (multiple temperature sensors) may include the first temperature sensor (S1) to the fourth temperature sensor (S4) described above.

[0132] In the step (S110) of measuring the temperature around the nozzle device (200, 200') or cavity gate through the sensing unit, the first temperature sensor (S1) can measure the temperature of the lower region of the heat transfer bushing (211), that is, the region adjacent to the nozzle tip (210) and the gate, and the second temperature sensor (S2) can measure the temperature of the upper region of the heat transfer bushing (211). Additionally, the third temperature sensor (S3) can measure the temperature on the main body side of the nozzle device (200, 200'), and the fourth temperature sensor (S4) can measure the temperature around the resin injection unit (100). The control unit (600) can sample and store or update the temperature information obtained from each temperature sensor in real time or periodically. Additionally, the control unit (600) can measure the temperature difference (e.g., △T) based on the measured temperature information. 13 = T1 - T3) or the rate of change of temperature over time (dT / dt) can be calculated.

[0133] The control method may include a step (S120) in which the control unit (600) determines a process state (e.g., overheated state, undercooled state, normal state) based on a measured temperature, temperature difference, or rate of change of temperature.

[0134] In the step (S120) of determining the process state, the control unit (600) can determine the operating mode according to the above-described mathematical formula 1. Specifically, the measured temperature rise rate (dT / dt) is a temperature rise rate threshold (θ) for operating the cooling element (214). h If it exceeds ), it is determined to be an overheated state, and the temperature drop rate threshold (θ) for operating the heating element (212) is used. c If it exceeds ) (i.e., dT / dt < -θ c It can be determined to be in a supercooled state. If the rate of increase and the rate of decrease are within their respective threshold ranges, it can be determined to be in a steady state. Here, the threshold θ h and θ cis the physical property values ​​of the reinforcing resin, namely the pyrolysis temperature (Td), melting temperature (Tm), and glass transition temperature (Tg), and the overheating reference time (t) set by the user. h It can be calculated based on ) and the supercooling reference time (tc).

[0135] The control method may perform a step (S132) in which the control unit (600) operates the cooling element (214) when it is determined that the state is overheated. In the step (S132) of operating the cooling element (214), the control unit (600) can rapidly lower the temperature around the nozzle tip (210) and the gate by supplying power to the cooling element (214) to cool the heat transfer bushing (211). Accordingly, molding instability such as overfilling, viscosity instability, carbonization / discoloration, which may occur when the resin becomes excessively thin due to instantaneous overheating, can be suppressed.

[0136] The control method may perform a step (S133) in which the control unit (600) operates the heating element (212) when it is determined that the state is in a supercooled state. In the step (S133) of operating the heating element (212), the control unit (600) can rapidly raise the temperature around the nozzle tip (210) and the gate by supplying power to the heating element (212) to heat the heat transfer bushing (211). Accordingly, the resin around the nozzle tip (210) can rapidly solidify, thereby preventing the flow path from becoming blocked or the nozzle from being damaged. Meanwhile, the control unit (600) [calculates] the rate of change (d(△T) of the temperature difference measured from two temperature sensors placed at different locations according to the above-described mathematical formula 2. 13 Calculate ) / dt), and if the rate of change of the temperature difference increases in the negative direction, the current applied to the heating element (212) can be increased preemptively. Additionally, the control unit (600) can increase the current applied to the heating element (212) more significantly if the ambient temperature obtained from the external temperature sensor according to the above-described mathematical formula 3 is lower than the reference temperature.

[0137] The control method may include a step (S131) ​​in which the control unit (600) does not operate the cooling element (214) and the heating element (212) when it is determined to be in a normal state. In the step (S131) ​​in which the cooling element (214) and the heating element (212) are not operated, the control unit (600) can reduce unnecessary power consumption and improve energy efficiency by stopping the power supply to the cooling element (214) and the heating element (212) or maintaining a standby state. In a normal state, the temperature around the nozzle tip (210) and the gate is stably maintained within the processing temperature range of the reinforcing resin, so molding quality can be ensured without separate cooling or heating intervention.

[0138] The above steps (S100 to S133) can be repeated during the injection cycle, and the control unit (600) can dynamically control the operation of the cooling element (214) and the heating element (212) by obtaining temperature information from the sensing unit in real time and determining the process state. Accordingly, molding defects caused by overheating and overcooling can be minimized even within the processing temperature range of the reinforcing resin, and maintenance issues such as nozzle clogging and nozzle replacement can be reduced, thereby improving process stability and productivity. In addition, by suppressing unnecessary cooling / heating operations, energy consumption can be reduced, and by reducing molding defects and rework, raw material waste and waste generation can be reduced, contributing to the reduction of environmental burden. Furthermore, the reinforcing resin product molded stably in this way ensures excellent mechanical properties and durability, thereby realizing the eco-friendly value of resource conservation through extended product lifespan.

[0139] At least one of the embodiments described above may also be implemented in the form of a recording medium containing computer-executable instructions, such as a program module executed by a computer. The computer-readable medium may be any available medium accessible by a computer and includes both volatile and non-volatile media, and both removable and non-removable media.

[0140] Although the apparatus and method of the present invention have been described in relation to specific embodiments, some or all of their components or operations may be implemented using a computer system having a general-purpose hardware architecture.

[0141] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

[0142] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0143] 1: Hot runner-based injection molding mold system 10: Hot Runner System 100: Resin input section 101: First heating unit 110: Cavity Plate 120: Holding plate 130: Spacer Plate 140: Top clamping plate 200, 200': First and second nozzle devices 200in: Inlet 210: Nozzle tip 211: Heat transfer bushing 212: Heating element 213: Insulation materials 214: Cooling element 221: 2-1 Heating Unit 222: 1st nozzle flow path 230: Nozzle cover 231: 2-2 Heating Unit 232: 2nd nozzle flow path 240: Valve pin 300, 300': 1st and 2nd cylinder devices 400: Air hole control terminal 500: Electrical control terminal 600: Control unit 700: Emergency Power Supply Unit MF: Manifold TL: Euro SP: Cavity S1: First temperature sensor S2: Second temperature sensor S3: Third temperature sensor S4: 4th temperature sensor

Claims

Claim 1 A mold system for injection molding a reinforcing resin comprises: a manifold having a resin flow path formed therein for distributing molten resin injected from an injection machine; a nozzle device connected to the manifold and extending downward, having an internal flow path formed therein for guiding the molten resin distributed from the manifold to the gate of a cavity, and having a cross-section that narrows as it extends downward; a heat transfer bushing formed of a high thermal conductivity material having a higher thermal conductivity than mold steel, surrounding the lower part of the nozzle device; a cooling element arranged to surround the outer surface of the heat transfer bushing to cool the heat transfer bushing; a heating element arranged to surround the outer surface of the heat transfer bushing to heat the heat transfer bushing; and a sensing unit for measuring the temperature around the nozzle device or the gate. A mold system for injection molding for eco-friendly reinforced resin injection, comprising: a control unit that receives temperature information from the sensing unit and controls the operation of the cooling element and the heating element based on the temperature information; wherein the sensing unit includes a plurality of temperature sensors each disposed at different locations within the mold; the control unit calculates a temperature difference based on temperature information measured from the plurality of temperature sensors, determines an overheating state or an overcooling state based on the temperature difference, and controls the operation of the cooling element and the heating element based on the determination result; wherein the control unit operates the cooling element when the rate of change of temperature over time measured from at least one of the plurality of temperature sensors exceeds a preset rate of increase threshold, and operates the heating element when the rate of change of temperature over time measured from at least one of the plurality of temperature sensors is less than a preset rate of decrease threshold; and wherein the control unit determines the operation mode of the cooling element and the heating element according to the following conditions. Operation mode = { Cooling (if dT / dt > +θ h ), heating (if dT / dt < -θ c ), wait (otherwise)}where,θ h = (Td - Tm) / t h θ c = (Tm - Tg) / tc, where T is the measured temperature (unit: ℃), t is time (unit: sec), dT / dt is the rate of change of the measured temperature over time (unit: ℃ / sec), Td is the thermal decomposition temperature of the reinforcing resin (unit: ℃), Tm is the melting temperature of the reinforcing resin (unit: ℃), Tg is the glass transition temperature of the reinforcing resin (unit: ℃), t is the overheating reference time set by the user (unit: sec), tc is the undercooling reference time set by the user (unit: sec), θ h is the temperature rise rate threshold for cooling element operation (unit: ℃ / sec), θ c is the temperature drop rate threshold (unit: ℃ / sec) for the operation of the heating element. Claim 2 A mold system for injection molding for eco-friendly reinforced resin injection, characterized in that, in claim 1, the cooling element is arranged to surround the upper outer surface of the heat transfer bushing, and the heating element is arranged to surround the lower outer surface of the heat transfer bushing. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 A mold system for injection molding for eco-friendly reinforced resin injection, wherein, in claim 1, the control unit calculates the rate of change over time of the temperature difference measured from two temperature sensors placed at different locations among the plurality of temperature sensors, and increases the current applied to the heating element when the rate of change of the temperature difference increases in the negative direction. Claim 10 In claim 9, the control unit acquires an ambient temperature from an external temperature sensor that measures an ambient temperature outside the mold system, and when the ambient temperature is lower than a reference temperature, increases the current applied to the heating element more significantly, characterized in that it is an injection molding mold system for eco-friendly reinforced resin injection. Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 A method for controlling a mold system for injection molding a reinforced resin, comprising: a step of measuring the temperature around a nozzle device or a gate through a sensing unit; a step of a control unit calculating a temperature difference or a rate of temperature change based on the measured temperature information; a step of the control unit determining an overheated state or an overcooled state based on the calculated result; and a step of, if an overheated state is determined, the control unit operating a cooling element arranged to surround the outer surface of a heat transfer bushing. A method for controlling an injection molding mold for eco-friendly reinforced resin injection, comprising: a step of, when the above-mentioned supercooling state is determined, the control unit activating a heating element arranged to surround the outer surface of the heat transfer bushing; wherein, in the determining step, the control unit determines the above-mentioned superheating state when the temperature change rate exceeds a preset rise rate threshold, and determines the above-mentioned supercooling state when the temperature change rate is less than a preset fall rate threshold, wherein the rise rate threshold is calculated by dividing the value obtained by subtracting the melting temperature from the thermal decomposition temperature of the reinforced resin by an overheating standard time set by a user, and the fall rate threshold is calculated by dividing the value obtained by subtracting the glass transition temperature from the melting temperature of the reinforced resin by an undercooling standard time set by a user. Claim 15 delete Claim 16 delete Claim 17 delete

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