Water-cooled hot runner nozzles and manifolds are widely used in high-speed thin-wall molds and easy-crystallization plastic molding. The surrounding cooling water channel creates a high-humidity and water-leakage-prone working environment, which easily invades ordinary thermocouple leads and terminals, causing insulation damage, short circuit and signal failure. Special waterproof and moisture-proof thermocouples are developed for water-cooled hot runner systems, with sealed waterproof structure to adapt to humid environment and ensure long-term stable temperature control.
Ordinary thermocouples adopt ordinary insulation layer and non-sealed lead outlet. When encountering cooling water leakage and workshop high humidity, moisture penetrates into the insulation gap, reduces insulation resistance, and causes weak short circuit between positive and negative wires. The temperature display jumps randomly, and the controller alarms frequently. In severe cases, the heating coil is burned out due to temperature runaway, causing heavy mold maintenance losses.
Waterproof hot runner thermocouples adopt fully integrated laser sealing structure at the probe and lead connection, with waterproof glue filling inside the lead outlet to block moisture penetration. The outer lead uses high-pressure waterproof and high-temperature resistant special material, which is not easy to absorb water and aging, and maintains stable insulation performance in long-term humid environment. The terminal end is equipped with waterproof protective sleeve to prevent cooling water splashing and steam erosion, avoiding terminal oxidation and poor contact.
In installation and wiring, waterproof thermocouples should avoid being directly soaked by cooling water, and the wiring path should stay away from water channel joints prone to leakage. Regularly check the water tightness of cooling pipeline to prevent long-term water immersion of thermocouple parts. Matching dedicated waterproof thermocouples for water-cooled hot runners can fundamentally solve hidden troubles such as moisture ingress, insulation attenuation and signal disorder, ensure the normal operation of water-cooled temperature control system, and extend the service life of thermocouples and heating components.
