hf welders, high frequency welding machine - High frequency welding machines, cutting plotters, PTFE welders, thermoforming machine, etfe welding machines

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High frequency (HF) welding process, also known as Radio Frequency (RF) and Dielectric welding, consists of  amalgamation of material by supplying HF energy in the form of an  electromagnetic field (27.12 MHz) which is normally applied between two  metal electrodes, plates or moulds. HF welding is accompanied with  certain pressure on the material surfaces to be joined. For this purpose  the HF welding machine are constructed.
HF Welding relies on certain properties  of the material being welded to cause the generation of heat in a  rapidly alternating electric field, so called dielectric heating of the  material to be welded. This means that only certain materials can be  welded using this technique. The dynamic electric field causes the  molecules in polar thermoplastics to oscillate. Depending on their  geometry and dipole moment, these molecules may translate some of this  oscillatory motion into thermal energy and cause heating of the  material. A measure of this interaction is the loss factor, which is  temperature and frequency dependent.
Advantage of high frequency welding
The great advantage of HF welding is the  speed of welding: the material is heated from the inside and fuses  quickly, within few seconds. In comparison with HF, in all other kinds  of welding methods (with filaments, hot air or infrared radiation) the  heat has to be added from the outside. It means the heat must first  penetrate the material in order to make it plastic enough to form a  weld. The main risk of this kind of treatment is burning the top layer  of welded material.

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HF welding rules, rods and electrode design - practical aspects read more
HF welding scheme
A high frequency voltage trigger the heating within the material, no extrinsic warming applied. Generated heat causes melting of materials and their integration. After cooling the welded surface under maintained pressure, the material is fused and a weld has been created. The weld joint can be at least as strong as the surrounding material – or even stronger. Four important factor influence the HF welding.
Imprtand factors for high frequency welding
Eventually the material will melt, and the force supplied by the electrode will melt (fuse) the two surfaces together. After cooling a permanent seam has been created. The resulting weld seam can be as strong – or even stronger – than the surrounding material.

Typical plastic (HF) welder consists of a high frequency generator (which creates the radio frequency current), a pneumatic press, an electrode that transfers the radio frequency current to the material that is being welded and a welding bench that holds the material in place.

molecular level of HF process
Final products done with HF welding
Common products manufactured with HF  welding method are tarpaulins, tents, ceilings, advertising outdoor  banners, waterbeds, inflatable boats, drip and blood bags, tensile  structures, conveyor belts, rain clothing, etc.
What materials can be HF welded
The most common material for high frequency welding is PVC (something called simply vinyl) and PU  (polyurethane). The material can be thick or thin, reinforced or coated.  It cab also be plain, coloured or structure/patterned.
Polyvinylchlorde (PVC) and polyurethanes (PU) are the most common  thermoplastics that are weldabele by HF also it is possbile to perform  HF welding on other types of materia inculding naylon, PA, ABS, modified  TOP, PETG, but particular attention should be pay on working  parameters. HF welding is not suitable for PTFE, polycarbonte,  polystyrne, polyethylene or polypropylene. Howeve, a special type of  mixed fabrics have been produced recently, which have the capability to  be HF welded.
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