- The filter of extruder is a small piece
most of everybody don't even notice.
- It is a very expensive piece of equipment if you
go with the wrong one.
- Also keep in mind filtration gives a counter-pressure
to the extruder and this limits the capacity so, the
bigger the better.
- Saving 10,000 here, means to spend 100,000 in production
- The first one coming up with an easy way to filter polymer scraps gets rich
in no time.
- There are many filters around, each
one (almost) good for each application
but, still, with lots of limits.
- When twenty years ago a German company
came up with the very first "back-flush"
self-cleaning screenchanger, it was
a kind of revolution and everybody was
under the impression filtering of polymers
wasn't an issue any more.
- Till this moment there is nothing
really very smart.
- The choice of the right filtration
system should be according the following
- - Cost of the operator to handle
- - Cost of the screens
- Of course, operator is needed if
screens need to be changed often or, with
continuous cleaning screenchanger, how
often operator should intervene to remove
the polymer automatically discharged.
- In both ways, operator is needed.
- The cost of the screens, that apply
to slide or rotating plate screenchangers,
is another important issue, from cost
point of view.
- In fact very many recyclers spend
an incredible amount of money just to
- All this means, from our point of
view, that if the filtration of polymer
is too expensive, you better work on
the line that's before the extruder
and try your best to remove contamination
before it gets to the extruder.
- Running some numbers, you may find
out you can buy and maintain another
piece of equipment in your recycling
system with the money you spend for
- Without forgetting you will have
a better quality product if contamination
is removed before extrusion, less wearing
of screw ..................