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. Best results are observed at 260°C – 315°C (500°F – 600°F). Do not exceed 360°C (680°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 extrusion grade HDPE that is at least as stiff as the production resin. Run system empty.
  2. Add Asaclean NCR 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 NCR).
  4. Purge the machine of the Asaclean NCR at normal screw speed.
  5. If contamination is still visible as the last of the Asaclean NCR 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 NCR residue to break down.
  8. When safe, displace the Asaclean NCR with the next resin.
  9. Begin production under normal processing conditions.

N Series Chemical Grade Purging Procedures