Mineral-insulated armored thermocouple has gradually replaced traditional bare wire and ordinary packaged sensors and become mainstream matching accessory for global mainstream hot runner brands including Mold-Masters, YUDO and domestic manufacturers, its unique compact encapsulation structure brings prominent advantages on high-temperature resistance, anti-vibration, anti-corrosion and measuring precision to adapt severe hot runner continuous production environment. The core production craft adopts seamless stainless steel outer sheath filled with high-purity compacted magnesium oxide insulation powder wrapping thermo-alloy core wire without inner air gap, fundamentally overcoming fatal defects of traditional open wire thermocouple such as easy short-circuit after damp and high-temperature oxidation drift.
Outstanding high-temperature durability is its core competitive merit: qualified mineral-insulated K-type armored thermocouple can stably work continuously within 0~550℃ long-term without obvious precision attenuation, fully satisfying PPS, PEEK ultra-high-temperature engineering plastic hot runner working requirement; J-type mineral-insulated specification adapts 0~750℃ conventional plastic molding temperature range and covers packaging and daily commodity hot runner mainstream application. Compact filling structure effectively blocks infiltration of corrosive plastic volatile gas and damp workshop water vapor, avoiding internal alloy wire corrosion damage happening frequently on non-armored ordinary thermocouple in plastic molding environment with lots of acid steam precipitation.
Strong mechanical toughness and anti-vibration performance make armored products suitable for bayonet embedded installation inside hot runner manifold and nozzle: seamless metal sheath resists extrusion damage from mold assembly collision and long-term cyclic vibration from clamping movement, reducing early failure rate caused by core wire fracture by over 70% compared with non-mineral insulated counterparts. Besides, ultra-fine customized diameter specification from 0.5mm to 3.0mm can realize bent forming processing on site according to mold installation space, satisfying compact special hot runner and micro medical multi-nozzle narrow-space layout demand which standard ordinary thermocouple cannot achieve.
The only shortcoming of mineral-insulated thermocouple is slightly higher unit production cost than cheap ordinary sensors, but longer service life and stable long-term precision reduce repeated replacement and shutdown maintenance expense comprehensively. At present, all imported original hot runner factory standard configuration adopts mineral-insulated thermocouple, and high-end domestic alternative spare parts also fully popularize armored structure to narrow technical gap with international original brand products step by step.
