This photo shows the black very thin plastic type filter that sits facing
the fan on a household Hitachi CV-SF8 vacuum cleaner.
Immediately behind this sits a plastic frame with a nylon fine mesh filter
and sitting in this frame is a black high density sponge filter. (doing a
search on this sponge filter, it's called a Mesh-Urethane filter).
This Mesh-Urethane filter is on the *right*
side of this photo, the black
one on the left is the reverse of the very thin plastic type filter referred
This Mesh-Urethane filter really restricts the air flow. Its a bit better
when I wash it out under the tap with soap and water but soon seems to clog
up again. I find it works quite well if I relace it entirely with a piece of
soft tissue toilet paper, and keep changing the paper and all the debris
that builds up behind it.
Now the question here is what exactly is this very thin plastic type filter
(if indeed it is actually a filter) doing? It's the one on the left in the
second photo. It seems to have microscopic slits in its surface, but when I
wash it, it wont pass water through it, which surely it would if its some
kind of filter? It's a thin flexible piece of plastic sheet, and seems
really strong. Almost like a sheet of carbon fibre.