Miniature compact hot runner widely used for micro electronic connector, precision medical implant accessory and tiny cosmetic shell gradually becomes mainstream product of YUDO mini series and domestic ultra-small multi-cavity mold manufacturers, and limited built-in wiring space inside compact mold structure makes custom fixed short-length wire thermocouple replace traditional long loose wire products and become mainstream matching option with prominent practical advantages. Ultra-narrow wiring trough inside mini hot runner cannot accommodate redundant coiled excess wire of standard long-cable thermocouple; overstocked scattered wire is easy to squeeze, bend and wear insulation coating during mold assembly and clamping, while tailor-made short wire strictly follows actual wiring distance measured on-site to eliminate leftover redundant cable and effectively avoid extrusion damage hidden trouble from source.
From signal transmission perspective, short wiring greatly reduces inherent line resistance of thermocouple, effectively curbs signal attenuation induced by overlong conductor and lowers systematic measuring error generated by line voltage drop; for miniature hot runner with narrow forming temperature window, the improvement of signal stability directly improves finished product dimensional consistency and reduces reject rate caused by temperature deviation. Meanwhile short exposed cold junction area effectively shrinks contact range with fluctuating workshop ambient temperature, easing compensation burden of controller cold junction compensation module and reducing environmental-induced measuring deviation obviously.
Many mold purchasers blindly adopt universal long-stock thermocouple to save customized ordering cost for mini hot runner at early procurement stage, and have to manually cut redundant wire on-site during installation; random wire cutting destroys original finished sealing structure of terminal and insulation transition, bringing hidden moisture invasion risk inside wire core and accelerating internal wire corrosion failure. Standard mini hot runner design specification requires confirming specific wiring length of each channel before thermocouple production, one-to-one customized production according to actual measured data. Although short customized thermocouple has slightly higher single processing cost than bulk standard spare goods, its low failure rate and long service cycle cut later maintenance cost greatly and obtain comprehensive cost advantage in full production cycle.
