Heating by means of electromagnetic induction has become an increasingly more popular method for heating ferrous and nonferrous wire-type products.
Applications for the cable and wire industry using induction heating provide reliable, repeatable, non-contact and energy-efficient heat in a minimal amount of time without flame. These applications range from structural ferrous and non-ferrous wires, copper and aluminium cable and conductors to fibre optic production, with such heat treatment processes as forming, forging, galvanizing, coating, drawing.
Typical applications include:
Drying post cleaning or removing water or solvent from coatings
Curing of liquid or powder based coatings. Providing a superior bond strength and surface finish
Diffusion of metallic coating
Pre heating for extrusion of polymer and metallic coatings
Heat treatment including: stress relieving, tempering, annealing, bright annealing, hardening, patenting etc.
Pre-heating for hot-forming or forging, especially important for specification alloys
Induction is also used for the preheating, post heating or annealing of metallic wire along with the
bonding/vulcanization of insulating or shielding within various cable products. Preheating applications can include heating wire prior to drawing it down or extruding. Post heating would typically include processes such a bonding, vulcanizing, curing or drying paint, adhesives or insulating materials.
Here's a stranded wire (diameter - 3 cm) heating simulated with CENOS Induction Heating simulation software, the objective of the simulation was to achieve surface-to-core temperature uniformity. In most single wire processing applications with wire diameters less than 3 mm, the entire wire is usually heated through and the criterion of obtaining surface-to-core temperature uniformity is not an issue unless extremely short heat times are used. Therefore, when heating multiple wires running in parallel or multi-strand cables, the criterion of providing an equal temperature in all wires regardless of their position inside the inductor becomes critical. The former is a result of the fact that external and internal wires of the cable may be heated differently because of the electromagnetic proximity effect and electromagnetic shielding of the external vs. internal wires.
Frequency: 5kHz Heating time: 15 sec. Current: 1000A Max. heating temperature: 850 degrees Celsius Material: Medium or Low carbon steel Coil type: multi-turn solenoid inductors are commonly used for heating single wires or multi-strand cables.