State of the art
State-of-the-art clamping mechanisms are designed to ensure that coil heaters remain firmly clamped to hot runner nozzles. However, the majority reach their limits pretty quickly: the material loses its stability under extreme temperatures and expands, causing the coil heater to uncontrollably detach itself from the nozzle. This creates pockets of air between the heating element and the nozzle, which makes it impossible to keep the temperature even and can very quickly lead to the complete failure of the coil heater due to overheating. In addition, screw connections, tension clamps or the complete moulding of the heating element mean that many of these clamping mechanisms also require a great deal of space, which is not available in standard hot runner moulds with little cavity spacing. The GC-jacket permanently holds and clamps and is basically a slotted metal tube that firmly clamps the GC-coil coil heater onto the cylindrical hot runner nozzle at temperatures of up to 550 °C. The material properties of the GCjacket, together with its thin-walled design, easily and effectively solve conventional clamping mechanism problems.