How to control the temperature and pressure during the packaging process of silicone rubber electric heaters?

To control the temperature and pressure during the encapsulation process of the silicone rubber electric heater, it is necessary to start from equipment selection, process parameter setting, process monitoring and feedback adjustment. The following are specific methods:
Choose appropriate equipment
Vulcanization equipment: According to the production scale and process requirements, select vulcanization equipment with high precision and good stability, such as flat vulcanizer, injection vulcanizer, etc. Flat vulcanizer is suitable for the encapsulation of larger-sized heaters and can provide uniform pressure and temperature distribution; injection vulcanizer is more suitable for heaters with complex shapes and can accurately control the injection amount and molding pressure of silicone rubber.
Temperature control device: Equipped with high-precision temperature control systems, such as thermocouples, temperature controllers, etc. Thermocouples are used to measure the vulcanization temperature in real time and transmit the temperature signal to the temperature controller. The temperature controller automatically adjusts the power of the heating device according to the difference between the set temperature and the actual measured temperature to achieve precise temperature control.
Pressure control device: Use pressure sensors and pressure regulating valves to control pressure. The pressure sensor monitors the pressure changes during the vulcanization process in real time and feeds back the pressure signal to the pressure regulating valve. The pressure regulating valve automatically adjusts the pressure according to the set pressure value to ensure that the pressure is stable within the specified range.
Accurately set process parameters
Temperature parameter setting: According to the characteristics of silicone rubber and the structure of the heating plate, the optimal vulcanization temperature is determined through experiments and data analysis. Generally speaking, the vulcanization temperature of silicone rubber is between 150℃ and 200℃, but the specific temperature needs to be adjusted according to different silicone rubber formulas and product requirements. At the same time, the heating rate and holding time should be set. The heating rate should not be too fast to prevent the silicone rubber surface from being vulcanized prematurely while the inside is not completely vulcanized; the holding time should be sufficient to ensure that the silicone rubber is fully vulcanized, but too long a holding time will cause the silicone rubber to age.
Pressure parameter setting: The setting of the vulcanization pressure should take into account factors such as the fluidity of the silicone rubber, the thickness and structure of the heating plate. Usually, the vulcanization pressure is between 5 and 15MPa. For thicker heating plates or products with complex structures, the pressure needs to be appropriately increased to ensure that the silicone rubber can fully fill the mold cavity and tightly combine with components such as resistance wires; for thinner heating plates, excessive pressure should be avoided to cause silicone rubber extrusion or damage to internal components.
Real-time monitoring and feedback adjustment
Temperature monitoring and adjustment: During the vulcanization process, the temperature is monitored in real time through thermocouples and temperature controllers. If the actual temperature deviates from the set temperature, the temperature controller will automatically adjust the power of the heating device. For example, when the temperature is too high, the temperature controller will reduce the heating power; when the temperature is too low, the heating power will be increased. At the same time, the operator should pay close attention to the temperature changes. If the temperature fluctuates abnormally or exceeds the control range, the machine should be stopped for inspection in time, and production can be continued after troubleshooting.
Pressure monitoring and adjustment: The pressure is monitored and adjusted in real time using pressure sensors and pressure regulating valves. When the pressure is higher than the set value, the pressure regulating valve will automatically release part of the pressure; when the pressure is lower than the set value, the pressure regulating valve will increase the pressure. In addition, the operator should also regularly check whether the pressure display value is accurate and whether the pressure control system is working properly. If there is a problem, repair or replace the relevant parts in time.
Maintain equipment regularly
Temperature control equipment maintenance: Regularly calibrate and maintain temperature control equipment such as thermocouples and temperature controllers to ensure their measurement accuracy and control performance. Clean the dust and dirt on the surface of the thermocouple, check whether the connection of the thermocouple is loose, and replace it in time if it is damaged. Upgrade the software and check the hardware of the temperature controller to ensure its normal operation.
Maintenance of pressure control equipment: Regularly check the accuracy and sensitivity of the pressure sensor, clean the probe of the pressure sensor to prevent clogging by impurities. Lubricate and maintain the pressure regulating valve to ensure that its valve core moves flexibly and without leakage. At the same time, check whether the pressure pipe and joints are loose or leaking, and repair them in time if there are any problems.