Correct usage of high-temperature oil-type mold temperature controller

High-temperature oil-based mold temperature controllers are widely used in industrial production, particularly in industries like plastic molding and rubber processing. They precisely regulate mold temperature, playing a crucial role in improving product quality and ensuring production efficiency. However, improper operation can affect equipment performance and even cause safety issues. Below is a guide to the correct usage.

I. Pre-start Preparation

(a) Checking the Equipment Appearance

Carefully inspect the mold temperature controller's casing for damage, deformation, or corrosion. Problems with the casing can affect equipment operation and even pose safety hazards. Also, check all pipes for damage, aging, or loosening. Pipes are the channels for heat transfer oil circulation; problems can easily lead to leaks, polluting the environment and potentially causing fires. Additionally, confirm that the buttons, indicator lights, and display screen on the control panel are functioning correctly. A malfunctioning control panel will prevent accurate operation and monitoring of the equipment.

(b) Checking the Electrical System

Make sure the power supply voltage matches the mold temperature controller's rated voltage. Different models have different rated voltages; voltage mismatch can burn out electrical components. A multimeter can be used to measure the power supply voltage to ensure it is within the specified range. Also check that the wiring connections are secure and that there are no short circuits or open circuits. Loose connections may lead to poor contact and equipment failure. Simultaneously, test the leakage protection device for proper function. Press the test button to see if the switch trips quickly; if it fails, repair or replace it promptly.

(III) Checking the Oil System

Check if the heat transfer oil level in the tank is within the normal range. If the level is too low, the circulating pump may draw in air, affecting the heat transfer oil circulation and heating effect; if the level is too high, the heat transfer oil may overflow. Generally, there are level indicators on the oil tank; the level should be controlled between the upper and lower limits of the indicator. Confirm that all valves are open and closed correctly. The inlet and outlet valves should be open normally, and bypass valves should be closed during normal operation. Incorrect valve status will hinder heat transfer oil circulation. In addition, check if the filter is clean. A clogged filter will increase the load on the circulating pump and reduce the heat transfer oil flow. It can be disassembled and cleaned with compressed air or a cleaning agent. If the filter is severely contaminated, replace the filter element promptly. (IV) Adding Heat Transfer Oil

Select a suitable high-temperature resistant synthetic heat transfer oil based on the operating temperature range and environment of the mold temperature controller. Inferior heat transfer oil will affect the lifespan and performance of the equipment. Add heat transfer oil through the expansion tank. Before adding, open the cap and pour in slowly, carefully observing the liquid level to prevent it from becoming too high. After adding, open the system vent valve, start the circulating pump, and purge the air from the oil circuit system. When the vent valve discharges a continuous flow of oil, close the vent valve.

II. Start-up Operation

(I) Starting the Circulating Pump

Connect the power supply to the mold temperature controller and turn on the main switch. The control panel will light up, displaying relevant parameters and status information. Locate the circulating pump start button on the control panel and press it. After starting, observe the pump's operating status to ensure there is no abnormal vibration or noise. Also, pay attention to the pump inlet and outlet pressures, which should be within the specified range. If the pressure is abnormal, investigate the cause immediately. After starting the circulating pump, let it run for a while to further purge the air from the system. (II) Setting the Temperature

After the circulating pump has stabilized, set the temperature on the control panel according to the actual production process requirements. Be careful not to exceed the equipment's maximum allowable temperature. Considering the equipment's heating rate and thermal inertia, the temperature can be set appropriately ahead or behind to ensure the mold temperature reaches the target value quickly and accurately. After setting, press the confirmation button.

(III) Starting the Heating System

Locate the heating system start button on the control panel and press it. The heating element will begin to heat the heat transfer oil. Observe the heating system's operating status, such as whether the heating indicator light is on and whether the heating power is normal. Note that the equipment's heating rate should be uniform and stable. If any abnormalities occur, promptly check the heating element, heat transfer oil flow rate, or temperature control system. During the equipment's heating process, closely monitor temperature changes. When the temperature approaches the set value, the heating system will automatically adjust its power to maintain the temperature within the set range, and the equipment will enter a constant temperature control state. III. Operation Monitoring

(I) Temperature Monitoring

Observe the actual temperature displayed on the control panel in real time to ensure it remains stable within the set range. Excessive temperature fluctuations affect product quality and production efficiency. Generally, high-temperature oil-type mold temperature controllers can achieve a temperature control accuracy of ±1℃ or even higher. Regularly measure the actual temperature of the mold or heated object with a thermometer and compare it with the temperature displayed on the mold temperature controller. If the deviation is large, it may be due to a faulty temperature sensor or improper installation, requiring calibration or replacement. Set a temperature alarm function, setting upper and lower temperature alarm values. When the temperature exceeds the range, the equipment will issue an audible and visual alarm to remind operators to handle the situation promptly and prevent malfunctions or safety accidents caused by abnormal temperatures.

(II) Pressure Monitoring

Observe the inlet and outlet pressure indicators of the circulating pump and maintain them within the equipment's specified range. Excessive pressure may indicate pipe blockage, improper valve closure, or circulating pump malfunction; insufficient pressure may indicate insufficient heat transfer oil level, pump cavitation, or system leakage. Regularly check system pressure fluctuations. Under normal circumstances, it should be relatively stable. If the fluctuations are excessive, it may be due to air in the system, deterioration of heat transfer oil quality, or wear and tear of equipment components. This can be resolved by venting, replacing the heat transfer oil, or repairing the equipment. Meanwhile, pay attention to the working status of the pressure sensor, and perform regular calibration and maintenance to ensure measurement accuracy and reliability.

(III) Equipment Operation Status Monitoring

Listen to the operating sound of the equipment. The operating sound of components such as the circulating pump, heating element, and fan should be smooth and even. If abnormal noises occur, such as friction sounds, impact sounds, or vibration sounds, it may be due to loose, worn, or damaged components, requiring immediate shutdown for inspection and repair. Observe the appearance of the equipment and check for any abnormalities such as leaks, smoke, or fire. Leaks in heat transfer oil may cause fires, and smoke or fire from electrical components may damage the equipment or even cause safety accidents. If any abnormality is found, immediately shut down the machine and take emergency measures. Regularly check all connection parts of the equipment, such as pipe joints, valves, and electrical terminals, to ensure that the connections are secure. Loose connections can lead to problems such as leaks and poor contact; tighten loose parts promptly. IV. Shutdown Procedure

(I) Stopping the Heating System

After the equipment has finished running, first press the heating system stop button on the control panel. The heating elements will stop heating. Wait for a period of time to allow the equipment temperature to drop naturally. During this process, do not immediately turn off the circulating pump; keep the heat transfer oil circulating to remove residual heat and prevent localized overheating and damage to the heating elements.

(II) Lowering the Temperature

When the equipment temperature drops below 70℃, gradually lower the temperature setpoint using the temperature adjustment buttons on the control panel, allowing the equipment to continue running until the temperature drops to a safe range. Closely monitor temperature changes during the temperature reduction process to avoid damaging the equipment due to a rapid drop. Also, pay attention to the equipment's operating status.

(III) Stopping the Circulating Pump

After the equipment temperature drops to a safe range, press the circulating pump stop button on the control panel. The circulating pump will stop running, the heat transfer oil will stop circulating, and the main power switch will be turned off to disconnect the power supply.

(IV) Other Shutdown Procedures

Close all valves on the equipment to restore it to its initial state for easy startup next time. Clean and maintain the equipment, removing surface dust, oil, and other impurities. Inspect and maintain all components, such as replacing worn parts and adding lubricating oil. Maintain accurate equipment operation records and shift handover records, noting start-up time, shutdown time, operating temperature, pressure, and any problems encountered during operation and their handling, providing a basis for equipment maintenance management.

V. Maintenance and Upkeep

(I) Regularly Replace Heat Transfer Oil

Depending on equipment usage and heat transfer oil quality, it is recommended to replace the heat transfer oil annually or every 2000-3000 hours of operation. If the heat transfer oil darkens in color, increases in viscosity, or raises its acid value, it should be replaced immediately. When replacing, first drain the old oil through the drain valve, clean the oil tank and pipelines with a cleaning agent to remove residual impurities and dirt, then add new heat transfer oil that meets the requirements, and purge air from the oil system.

(II) Clean the Filter

Clean the filter monthly using the same method as the pre-start inspection and cleaning. After disassembly, clean with compressed air or a cleaning agent. If the filter element is damaged or severely clogged, replace it promptly. During cleaning, carefully observe the type and quantity of impurities in the filter. A large amount of metal shavings, particles, or other impurities may indicate severe wear of internal components, requiring further inspection and repair.

(III) Inspecting the Heating Element

Inspect the heating element's operating status quarterly, checking for damage, deformation, or aging. Replace any elements with cracks or peeling. Measure the heating element's resistance with a multimeter and compare it to the standard value. A significant deviation indicates a potential malfunction, requiring repair or replacement. Regularly clean the heating element's surface with a clean cloth or brush to remove oil, carbon deposits, and other dirt, ensuring effective heat dissipation and heating.

(IV) Inspecting the Circulating Pump

Regularly check the circulating pump's operation, including vibration, noise, and inlet/outlet pressure. Abnormal vibration or noise may indicate wear of internal pump components, damaged bearings, or pump shaft misalignment, requiring timely repair or replacement. Check the circulating pump's seals to ensure no leakage at the pump shaft. Replace damaged seals promptly to prevent heat transfer oil leakage. Regularly lubricate the circulating pump's bearings and other parts by adding appropriate amounts of lubricating oil or grease to ensure normal pump operation and extend its service life. (V) Electrical System Inspection

Regularly check the electrical system wiring terminals for tightness, looseness, and oxidation. Tighten any loose terminals and clean or replace any oxidized ones. Check the working status of electrical components such as contactors, relays, and switches. Replace any damaged, short-circuited, or open-circuited components immediately. Use an insulation resistance meter to test the insulation resistance of the electrical system to ensure good insulation performance. Low insulation resistance may cause equipment leakage and safety accidents. Repair or replace any non-compliant parts promptly.

Proper use and maintenance of high-temperature oil-based mold temperature controllers ensure stable equipment operation, extend service life, improve production efficiency, and guarantee product quality. This article aims to help you master the use of high-temperature oil-based mold temperature controllers.