Typically filters trap oils and greases so you need a detergent to break those down and remove them.
Good EDM filters are designed to trap particles. As they load up the pressure drives the particles deeper and deeper into the weave. You might need compressed air to blow them out.
Most older edm’s using paper EDM filters cartridge ran from the outside-in and you could hose them off and sling ’em a bit and get some more hours out of them.
All of our newer EDM machines filter from the inside-out and it’s near impossible to clean and reuse the filters.
Cheaper to just replace them than spend the time and effort to clean them., First, I would look for cheaper replacements. Filter cost has little to do with quality.
Maybe try larger filter size. Remember that the rating is the largest size particle the filter lets through but they also trap much smaller particles.
Example: When we test we put filters in a system we use a laser counter to count and measure particles before and after filtering. A filter system with a 25 micron bag and a 10 micron cartridge filter will remove well over 99% of all particles down to one micron.
When we set up a system with a 25 micron bag and a 1 micron cartridge we remove about 99.9% of all particles down to and including one micron. Filter change is typically ever 2 to 3 days.
25 and 1 = 99.9% and 3 days
When we set up with a 25 micron bag and a 10 micron cartridge we remove a bout 99.4% of all particles down to and including one micron and filter change is every month or two. 25 and 10 = 99.4% and 45 days
You might switch to a higher micron paper and see what happens.
Paper filters sometimes advance pretty fast. Remember that as a filter loads up the filtering actually gets better. (However there is a release point eventually.) You might see if slowing your paper speed down is possible.
Most of the time, Clean EDM filter cartridge will only gain you a small number of additional hours, and eventually they will fail and let dirty water into places you really don’t want it .
This is a lot of work and do not recommend it: There has been a time or two when I was caught without replacement filters and the job had to go out. I removed the filters and washed them with high pressure water and a brush, caught all the water in a barrel. Later put the barrel in the sun to evap. the water. The dust that is left must be treated as hazardous waste. Doing this got me maybe 30-50% additional use from the filters, but it was time consuming. Filters cannot be efficiently cleaned as the dirt is caught in between the pleats. A couple of times I have changed filters and put the old ones in the sun to dry. When dry I pounded the dirt from them, saved the dirt as hazardous waste in a bucket and reused the filters later. I think I got about 50% reuse from them.
Over the years I have seen many types of filtration come and go. At one time we used Diatomaceous Earth filtration (the same thing they use on pools). This type of EDM filter had to be taken apart and hosed down to remove the D/E and the EDM dirt. Very messy. We then moved to a pleated cloth element filter. With this type you would let the filter sit out in the sun or on the shop floor in the winter to dry. Then you had to use various methods to remove the dirt ranging from hitting the filter on the floor to using an air gun the blow the dirt off or using a hose to wash the dirt off. All of them were very time consuming and dirty to say the least. You will also find that the filters that you reuse will not last any where near as long as the new ones. We now use disposable filters due to the cost of the labor required to clean the old EDM filters.
Here in California as in most states we are not allow to through our EDM filters in the trash. We are required to pay to have them hauled off as Hazardous waste.
There are a couple of companies that make aftermarket systems with cleanable filters, you could get one central system to run all your machines. It won’t be cheap.