Nickel Chromium (80-20 NiCr) wire is used to form the resistance coil that produces the heat within the Watt-Flex® cartridge heater. These coils can be wound by hand or by machine, depending on the quantity of the order ... it certainly takes less time to set up and hand wind an order of ten heaters than it does to perform a machine set-up.
Each gauge of resistance wire has a different resistive value per inch of length, depending on its diameter. The coil to be wound is specified by a computer program that calculates the overall required resistive value of the heater (volts squared divided by watts). Coils are wound and resistance is checked immediately on a multi-meter at each winding station.
Contamination on the resistance coil can create heater problems, so the coils are treated carefully and sent to an ultrasonic cleaner. Then a sample coil, wound with that batch, is tested to ensure no oils are present before being sent to assembly. Quality coils produce quality heaters.
Dalton Electric Heating Co., Inc was founded in 1921 to manufacture industrial heaters.
Since 1989 we manufacture all our heaters in Ipswich Massachusetts
Today, Dalton's Watt-Flex Cartridge Heaters and Diff-Therm Platen heaters are used throughout the world in manufacturing industries including aerospace, automotive, plastics, composites, and many others.