Domestic cross-provincial land transportation and overseas sea transportation of hot runner thermocouples face complex environmental hazards including extrusion deformation, sea salt fog corrosion, low-temperature cold brittling and vibration wire fracture. Special multi-layer protective packaging standards are formulated for different transport modes to avoid new probes arriving at customer destinations with bent sheaths, oxidized sensing junctions and cracked cable insulation. Packaging schemes are divided into single-piece vacuum inner packaging, batch shock-absorbing intermediate packaging and outer waterproof transport carton three-layer protection, with differentiated reinforcement measures for sea freight long-distance shipping.
Single-piece inner vacuum packaging is the core anti-corrosion protection layer for every thermocouple. Each finished probe is individually placed into a PE vacuum bag with one bag of silica gel desiccant, then fully vacuum-sealed to isolate air moisture, salt fog and floating dust during transportation. For export sea freight thermocouples, anti-salt-fog passivation film is pre-treated on sheath surfaces before vacuum packaging to resist chloride ion corrosion from sea air. Ultra-miniature bent micro thermocouples add soft foam plastic inner sleeves outside the sheath before vacuum sealing to prevent bending deformation under extrusion pressure during stacking. Spare integrated heater-thermocouple assemblies with rigid metal structures use thick EVA foam inner molds to fix the whole component, avoiding collision scratch damage of sensing heads and wiring terminals.
Batch shock-absorbing intermediate packaging eliminates vibration and extrusion damage during transport loading and unloading. Vacuum-sealed single thermocouples are neatly placed into partitioned EPE shock-absorbing foam boxes with independent grid slots for each specification, with gaps filled by soft foam strips to prevent internal sliding collision during vehicle bumping. The foam box cover is fully sealed with waterproof adhesive tape, and the box interior is sprayed with anti-static agent to avoid static dust adsorption on probe surfaces. Domestic short-distance land transport can use 2cm thick ordinary EPE foam; sea freight long-distance shipments upgrade to 5cm high-density shock-absorbing foam to withstand continuous ship hull vibration over 20–30 day sea voyages. All bent probes are fixed with foam positioning blocks to lock the bending angle and prevent internal wire fatigue fracture from repeated shaking.
Outer transport carton waterproof reinforcement adapts to different transport environments. Domestic land transport uses double-layer corrugated cartons with waterproof film wrapped around the whole box surface, with wooden support strips at the four corners of the carton to resist forklift extrusion impact. Export sea freight cartons adopt reinforced seven-layer corrugated waterproof cartons, lined with full-size plastic waterproof film inside the box, and all carton seams are sealed with butyl waterproof adhesive tape to block sea water condensate and salt fog penetration. The carton exterior prints clear specification labels, fragile handling marks, moisture-proof and anti-extrusion warning icons in both Chinese and English, and marks the placement direction to avoid inverted stacking that crushes internal probes.
Additional differentiated transport auxiliary protection measures are added according to delivery cycle. Long-term sea shipments store extra desiccant bags inside foam boxes to absorb condensate generated by temperature difference changes in shipping containers; winter northbound land transport adds thermal insulation cotton wrapping outside foam boxes to prevent cable insulation brittling under low-temperature transport conditions. Each carton attaches a complete batch certification document bag sealed in waterproof plastic to avoid test report paper dampening and blurring.
Multi-layer standardized transport packaging eliminates deformation, corrosion and insulation damage of thermocouples during long-distance cross-regional delivery, ensuring that customers receive probes with complete factory original performance without pre-installation degradation faults.
