Hot wire cutting

Hot wire cutting is the technique of choice for shaping expanded polymer foams — EPS (polystyrene), EPP, XPS, expanded polyethylene — by exploiting the thermal resistance of a metal wire carrying an electric current. The wire heats up to temperatures of 100–300 °C and melts the polymer along its path without producing dust or chips: the result is a smooth, compact-surface cut free of the microparticles typical of abrasive processes.

Machines range from simple manual bench stations (with a fixed or oscillating wire bow) to 2D and 4-axis CNC systems capable of cutting wing profiles, architectural models, three-dimensional signage and set-design components. Feed speed and the voltage applied to the wire are the critical parameters: too slow produces glossy surfaces and shrinkage; too fast leaves the cut open and ragged. In the maker context, this technology is irreplaceable for those working with RC models, architecture and stage design.