Resistance welding technology is one of the welding processes that requires the least amount of energy compared to other welding processes.
In the case of projection welding with a small diameter – especially when welding functional elements (nuts, washers, bolts), CD welding and MFDC welding compete:
• CD welding with short welding times of approx. 15 ms and high welding currents of 120 kA
• MFDC welding with longer welding times of up to 1000 ms and lower currents of up to 60 kA
In a series of tests carried out at GLAMAtronic, nuts were welded onto a disc and the energy consumption of the two processes was compared. The criterion in each case was an identical mechanical strength.
For MFDC welding, 28.1 kWs must be applied per weld, whereas for CD welding (standard characteristic) with 10.4 kWs not even half of the value is necessary. Based on serial production with 4 welds per minute, 8 hours per shift and 2 shifts (3,840 welds), this results in 30.0 kWh for MF welding and 11.1 kWh for KE welding.
The result can be summarized that the energy consumption for projection welding with a CD welding machine is about 2/3 lower than with an MFDC welding machine!