High-power lasers are becoming increasingly efficient at cutting thick sheet metal
A comparison of cutting processes: investment costs as a decisive factor
A study by the Politecnico di Milano examined four cutting processes and highlights where lasers are economically competitive.
Laser cutting enables precise and flexible metalworking, but becomes less efficient when cutting thick sheets. Researchers at the Politecnico di Milano have compared the productivity and cost-effectiveness of laser, plasma, oxy-fuel and waterjet cutting for carbon steel with a material thickness of ten millimetres or more.
Lasers excel with thinner sheets
The results show that lasers are competitive in terms of productivity and cost when cutting materials up to a thickness of 20 to 30 millimetres. For thicker sheets, plasma cutting offers an economic advantage. However, high-power lasers ranging from 30 to 60 kilowatts can achieve cutting speeds comparable to those of high-performance plasma systems. Oxy-fuel cutting becomes competitive with 6-kW lasers from around 20 millimetres; at thicknesses of more than 40 millimetres, it also outperforms certain laser and plasma systems. Waterjet cutting exhibits the lowest productivity in the comparison examined.
A major cost driver in laser cutting is the high initial investment: the study estimates the cost of a 30-kW laser system at 850,000 euros and that of a 300-A plasma system at 155,000 euros. For sheet metal 30 millimetres thick, the price of the laser system would have to fall by around 25 per cent for both processes to be equally expensive. For thicker materials, reductions of 25 to 50 per cent would be necessary to offset the cost difference.
