Why do filter cartridges in CNC EDM machines, which are otherwise performing reliably, sometimes fail so quickly? Why does the same problem persist even after replacing them with high-quality cartridges? Why does the service life of filter cartridges shorten significantly—or even result in rupture—when the machining conditions for wire-cut EDM remain unchanged?
We have observed a common factor among these users: the maintenance intervals for changing the coolant in their CNC wire-cut EDM equipment are too long. Typically, this exceeds six months; indeed, some users only replace the filter cartridges without ever changing the water.
A study in the United States has demonstrated that when the water tank is not cleaned and fresh water is not replaced for extended periods, the wire cutting coolant is prone to bacterial growth, particularly as the weather warms and temperatures rise. These bacteria cause minute particles in the water to agglomerate into a viscous sludge, rapidly clogging the filter paper and leading to premature failure of the filter cartridge.
Solution:
- Clean the water tank of the CNC wire-cut EDM machine regularly and replace the water, ensuring this is done at intervals of no more than three months;
- Install sterilisation devices such as ozone or ultraviolet (UV) systems.