Why Is Mineral Insulated Thermocouple the First Choice for Hot Runner Long Service Life

Mineral insulated thermocouples increasingly replaced the conventional insulated thermocouples as the standard configuration of medium and high-end hot runner systems, depending on the better high temperature resistance, vibration resistance and airtight stability. Its internal structure employs compacted magnesium oxide insulating filler to securely wrap the thermoelectric wire and is entirely sealed with the seamless metal sheath, totally isolating the external high temperature, moisture, corrosive gas and mechanical extrusion.

In the long-term high temperature working environment above 300°C, ordinary thermocouples are prone to ageing of the insulation layer, melting and carbonisation, resulting in a short circuit and signal drift. The mineral insulated structure can sustain the steady insulation performance under the continuous high temperature, avoid the ageing failure and keep the temperature measuring accuracy unchanged for a long cycle. Meanwhile, overall robust structure has strong anti-vibration capability, adapts to frequent mould opening and shutting and high-speed cycle impact, and will not generate internal wire breakage or virtual connection.

The complete laser welding sealing method ensures airtightness and corrosion resistance, preventing the penetration of volatile gas and oil vapour from the plastic raw materials into the probe. For flame retardant plastics, modified materials and recycled plastics easy to produce corrosive smoke, mineral insulated thermocouples may effectively resist chemical erosion and avoid the sheath perforation and the internal wire corrosion.

It also has the short bending radius, flexible wire layout, appropriate for the complex mould internal wiring and restricted installation area. It also possesses the rapid thermal response speed, accurate real-time feedback of temperature, and enabling the temperature controller to realise accurate closed loop control. For injection moulding firms, mineral insulated thermocouples are the most cost-effective long-term option to pursue low failure rate, long maintenance cycle and steady mass production.333