Problems related to cast iron machining mostly result from machined graphite dust and CI chips.  Even today we are struggling to find a reliable and effective way to filter cast-iron chips and fines.  Cast-iron fines are notoriously hard to remove, requiring manufacturers to use vacuum filters or replaceable media to try to extend metalworking fluid life and prevent fines from circulating back to the machine.  Vacuum filters are more expensive than gravity bed. The cost of removal, replacement and disposal of paper filters has increased significantly.  Cyclonic filters require higher maintenance than many systems.

Hennig Cast-Iron CDF Filtration System is a potential alternative for these systems.  The system is self-cleaning, permanent-media filtration technology applied to cast-iron machining operations to eliminate cast-iron chips and fines without  use of disposable filter media.   The new system uses the patented Hennig CDF (Chip Disc Filtration) technology, with a history based on hundreds of installations worldwide.  The new Hennig filtration system can also accommodate other material types in addition to cast-iron.