Coil & Cable Heaters

Cable heaters are highly versatile, high performance mini-tubular heaters that are used in applications where a large amount of heat is required in a confined space. These heaters are fully annealed and can be bent into various shapes and configurations. Their standard cross-section is round but can be formed into a square or a rectangle to improve heat transfer. The sheath material is stainless steel 304, which provides adequate resistance against temperature oxidation and corrosion. The heating core type depends on the electrical and thermal characteristics of the heater. The core is made by embedding either Nickel-Chrome mini-coils or straight, solid resistive wires inside a highly compacted Magnesium Oxide insulating medium. The connection between the main power leads and the internal fine wires is done inside transition adaptors. These adaptors, which remain relatively cold and protect the power leads during operation, have larger diameters than the heater cross-section. Cable heaters can have up to 35w/in2 watt-density and can operate at temperatures as high as 1200°F in a continuous mode (1500°F intermittent).

Uses of Coil Heaters

Coil heaters are special cable heaters that have been shaped into a coil. These heaters are successfully used as powerful heating cells in plastic injection molding hot-runner nozzles. Coil and cable heaters can accommodate "J" or "K" type thermocouple sensors which are positioned internally at the tip or in the middle of the heater. Moreover, coil and cable heaters can have a profiled or a distributed-wattage configuration. It should be noted that although cable heaters are malleable and can acquire any shape, they should be formed into a final shape in a single attempt. Forming and bending operations harden the outside stainless-steel shell, and additional annealing might become necessary if re-changing the form is required