The patented method includes a secondary preheater coil placed before the main coil. The distance between the two leaves enough time for the heat to penetrate throughout the conductor before further preheating. The main coil preheats at much higher temperatures, and gives a constant temperature throughout the conductor cross section. However, the conductor preheating must be exercised with caution to avoid the undesired effects of excessive preheating.
The new technique is used for both aluminum and copper conductors. It is available in new Maillefer CV lines, and as an upgrade for existing lines.