Differences in Application Effects Between K-type and T-type Hot Runner Thermocouples

K-type and T-type thermocouples are two popular mainstream models in the field of hot runner temperature measurement. Users must choose them sensibly based on production process requirements because they differ significantly in terms of alloy material composition, applicable temperature range, temperature measurement precision, environmental adaptability, and actual molding application effects.

The most popular general-purpose thermocouple in the injection molding business is the K-type thermocouple, which is composed of nickel-chromium and nickel-silicon alloy elements. Its broad temperature adaption range, which can operate steadily for extended periods of time between 0°C and 1200°C and fully cover all molding temperature intervals of the majority of general and engineering plastics, is its greatest benefit. It can withstand the erosion of the majority of plastic volatile gasses, has a strong resistance to high-temperature oxidation, and is appropriate for severe production conditions where glass fiber, flame retardant, and other modified additives are added. Additionally, K-type thermocouples can meet the continuous production needs of the majority of injection molding factories due to their complete supporting accessories, low market procurement price, easy replacement and maintenance, and good compatibility with all mainstream hot runner temperature controllers.

The T-type thermocouple is a low-temperature, high-precision temperature monitoring device that uses a copper-constantan alloy construction. It is not appropriate for high-temperature molding of technical plastics, and its long-term stable working temperature is limited below 350°C. Its primary advantages are its extremely low thermal drift value, ultrahigh temperature measurement accuracy, tiny repeated measurement error, and sensitive temperature sensing response. Because to long-term constant temperature heat retention, it performs steadily in low and medium temperature environments and won't cause noticeable data deviations. In the low-temperature constant temperature stage, the temperature feedback data is more precise and steady, and its signal linearity is good.

K-type thermocouples are primarily utilized in hot runner production of high-temperature engineering plastics, modified filled plastics, and large multi-cavity molds in actual production applications, with an emphasis on overall cost performance and environmental adaptability. T-type thermocouples are primarily utilized in low-temperature molding applications, such as food-grade soft plastics, precise low-temperature plastic components, and medical low-temperature injection products, which have low requirements for high-temperature resistance and extremely strict temperature control accuracy.

Mixing the two types of thermocouples at random during the model selection process is strictly prohibited since doing so will cause significant temperature data variance and disorder in the heating control logic. In order to guaranty that the temperature control effect is in line with the production process standards and continuously increase the qualified rate of injection molded products, businesses should use molding temperature, production environment, and product precision requirements as the fundamental standards when choosing matched thermocouple models.