PRESA – High frequency machine for drying and formingpressboard insulation profiles used in high power transformer coils. The HF machine is specially designed for forming and dielectric drying and forming insulating elements from 0,5 mm to 5 mm thick – made from wet insulation pressboard produced from pure unbleached cellulose taken from long-fibered coniferous wood.
The HF drying and forming process is time efficient and prevents overheating and deformations. The ready made profiles and elements allow optimal adaptation to the electric field conditions in the transformer.
The insulation components made with our individually customized machines the are suitable for use in oil-filled power transformers, due to their high purity, mechanical strength and ability to be impregnated with oil.
Full diagnostic testing and certification of the local factory EMC/EMS parameters according to the latest guidelines required by the CE & UL standards. We have our own ISO 17025 certified production control and EMC laboratory providing validation of each required process parameters and the whole technological production cycle.
High frequency welders manufactured by Zemat Technology Group are designed and built in accordance with current European requirements for machine safety and energy efficiency. The machine design incorporates technical solutions that enhance welding process stability, reduce energy losses, and increase production repeatability.
HF Smart Control™ is a set of structural and electronic solutions implemented in high frequency welders, including:
The HF/RH welders use high frequency generators with microprocessor-based power control, enabling precise adjustment of energy to the process parameters. The system continuously monitors operating conditions and dynamically regulates power in real time. As a result, energy consumption can be reduced compared to heat sealing technologies and many impulse-based systems. The actual level of savings depends on the material, application, and process settings.
The ATS ensures precise impedance matching and automatic generator tuning during machine operation. This stabilizes the welding process, reduces the risk of instability, and minimizes the possibility of arcing. Fast reflected power control protects HF circuit components and improves weld repeatability.
Modern HF generators achieve energy efficiency levels of approximately 70–90%, depending on configuration and operating conditions. Band-pass filters reduce harmonic distortion, while lower thermal losses decrease heating of machine components. This results in stable operation and extended service life of key components.
