High melt pressure is a constant challenge in hot runner systems, especially when processing engineering plastics with high filling speeds. Extreme pressure can deform poorly constructed thermocouple probes, damage seals, and force molten material into sensor cavities. Over time, this leads to signal drift, short circuits, or complete failure.
Thermocouples designed for hot runners use reinforced sheaths and sealed junctions to withstand internal mold pressures. Mineral-insulated construction provides rigidity while maintaining flexibility. The probe must be securely mounted to avoid movement under pressure, which could cause inconsistent readings or physical damage.
In high-pressure applications, even minor probe movement creates measurement errors. Leading brands use threaded or bayonet mounts with high-pressure seals to maintain sensor position. Understanding melt pressure effects helps users select heavy-duty thermocouples that maintain accuracy under demanding conditions.
