1. Empty the system of the production resin, and make sure the feed areas are clean. Do not remove the die.
  2. If possible, and safe, increase temperatures in all zones after the extruder by 55⁰C (100⁰F) above production temperature, but do not exceed 290⁰C (555°F).

If purging a heat sensitive resin, do not exceed the safe processing temperature of the material. This purge procedure may need to be repeated at elevated temperatures to remove all contamination.

  1. Flush the machine by running 1-4 system volumes of clean, natural polyethylene that is at least as stiff as the production resin. Run system empty.
  2. Add Asaclean NCF at normal screw speed until the purge extrudes uniformly from the die.
  3. Soak the system with the screw turning at minimum controllable rpm for 20-30 minutes (if sealing, turn off all heaters with the system full of Asaclean NCF).
  4. Purge the machine of the Asaclean NCF at normal screw speed.
  5. If contamination is still visible as the last of the NCF leaves the system, repeat steps 4-6.
  6. Set temperature profile for next resin to run.
  7. Wait 5 minutes with an empty barrel for the Asaclean NCF residue to break down.
  8. When safe, displace the Asaclean NCF with the next resin.
  9. Begin production under normal processing conditions.

N Series Chemical Grade Purging Procedures