High-frequency welding (HF), also known as radio frequency or dielectric welding, consists of HF energy passing through the material in the form of an electromagnetic field (27,12 MHz). The welding equipment is typically composed of: a high frequency generator, an air press, an electrode that transfers the radio frequency current to the material that has to be welded, and a metal welding plane, also suitable to hold the material in position.
The field of application of this technology is really extremely wide, usually depending on the shape of the molds, plates, etc., that is, the two metal electrodes between which the electromagnetic field is applied. For the best result, the right pressure to be exerted on the material must be chosen first, then the temperature, finally the time (both welding and cooling of the parts).
The material must have specific properties of dielectric nature; in other words, only some materials can be welded using this technique. PVC and PU are by far the most chosen whether thin or thick, coated, reinforced or otherwise; other materials (nylon, PA, ABS, PETG) could be chosen, however the working parameters can significantly worsen. They are not suitable for HF welding, for example, Polycarbonate, Polyethylene, Polystyrene, Polypropylene, PTFE. This is because the high-frequency voltage must be able to trigger the internal heating of the material, without or regardless of the application of a temperature increase from outside. In suitable materials, the heat generated internally causes the materials to merge permanently and relatively quickly.
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