High frequency machine for drying and forming preshpan izolation collars

PRESA – High frequency machine for drying and forming preshpan izolation collars. The machine is specially designed for forming and dielectric drying insulating elements from 0,5 mm to 3 mm thick, made of broad range of raw material moisture presspan /pressboard for high voltage power transformers.


High frequency drying

PRESA equipped with customized forming/shaping tools enable production of yoke collars and corner collars for inner and outer circumference shapes. The customized press table with dimensions of 1300 mm x 800 mm allows production of a wide range of collars; especially large collars according to your drawings.
Thanks to this machine, we may dry and form collars from variety kinds of preshpan (wet and dry preshpan LD or HD) within the range from 0,5 to 5 mm thickness. In the process of drying we use antithetic energy of electric field with frequency of 27,12 MHz. Preshpan is heated steadily in all volume to the temperature of boiling. In this process we have an effect of dielectric loss of water from preshpan. In dependence of preshpan thickness, drying and obtaining final product may take something about 15 minutes.
Thanks to aluminium forms we may get collars with radius in the range starting from R300 to R2000. There are two kinds of collars we may produce: external (outners) and internal (inners).

Why is our technology unique?

WCS™ Weld Check System
Verifying and signaling the HF/RF weld preset parameters / end cycle process. Collects all data pertaining to each weld cycle for remote diagnosis of any issues or problems with machine setup or power output.
QuickGrip™ System
System for quick and easy replacement of electrodes. The electrodes are attached with pneumatic clamps activated from the control panel.
AntiFlash™ System
Ultra-fast Solid-State ARC sensor & full output overload protection.
ZTG iCOM™ System
Built-in VPN client and VNC server making up the internet interface allowing remote control of machine parameters, weld cycle and diagnostics or software upgrade.
Safety guards
Special guards with safety limit switches designed for protection against electromagnetic radiation (compliance with EN and EMC standards).


ZEMAT TG High Frequency welding machines are designed and built to very strict European Environmental and Safety regulations and have custom design solutions for weld and safety control.

ECO-Friendly HF Technology incorporated in the High Frequency machines contains:

Low energy consumption

| Energy efficient ECO HF generators with microprocessor control of output power
| Low power consumption and real time power output recognition
| 90% less power consumption than with traditional heat powered welding systems

AutoTuning System™

| Dynamic High-performance HF impedance matching
| Dynamic Auto Tuning and Arc protection unit
| Ultra-fast reflected power control

Highly efficient and stable HF generators

| RF power output efficiency at 70-90%
| Harmonic distortions eliminated by frequency band filters
| Very limited heat dissipation preventing overheating