Their principle consists in exposing the material to a high-frequency magnetic field created by a specific generator; the magnetic field is generally produced by two capacitive plates or blades through which the material is interposed.
The peculiarity of that system is that it induces heat starting from inside the material instead of transmitting it through contact from outside. Therefore, glue sets more efficiently and also more rapidly.
This method is used for hot presses in general but is ideal use when very thick materials or materials with vertical glue lines, such as stripped panels and glue laminated beams are to be pressed. It is also particularly indicated for bending solid wood and for making curved plywood.