Hot runner products are classified by structure, application, and control method, with each type tailored to specific molding needs. The most common classification is by nozzle type: open-type hot runners and valve-gated hot runners. Open-type systems are cost-effective, with simple maintenance, suitable for general plastics like PP, PE, and ABS in household products and low-precision electronics. They feature a direct melt flow without valve control, though prone to minor gate marks and stringing. Valve-gated systems, by contrast, use a mechanical valve pin to open/close the gate, ensuring zero gate marks and preventing leakage. Ideal for high-precision parts in medical, automotive, and cosmetics, they support multi-cavity and multi-color molding.
By system structure, hot runners are divided into single-point and multi-point systems. Single-point systems serve one cavity, used for large parts like automotive bumpers and home appliance shells. Multi-point systems, with multiple nozzles connected to a manifold, enable simultaneous molding of multiple parts, widely used in packaging (e.g., bottle caps) and electronics (e.g., connectors). Specialized products include miniature hot runners for micro-parts (e.g., precision gears, electronic connectors) with cavity sizes as small as 0.37mm, and high-temperature hot runners for engineering plastics requiring 300°C+ temperatures, equipped with heat-resistant alloys and advanced insulation. Thermocouples, as critical components, are integrated into all systems to monitor and regulate temperature, ensuring stable operation.
