PF Grade | Temperature Change Extrusion Purging Instructions


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Asaclean® PF Grade Extrusion Purging Instructions for Transitions from High Heat Resins to Other Resins Above 370ºC (700ºF) to below 300ºC (570ºF)

Notes Before Purging

  • Asaclean® PF Grade should not be left idle in the barrel for any period of time above 370ºC (700ºF) as decomposition may occur.
  • Keep the barrel full of Asaclean® PF Grade at all times to prevent oxygen from entering the barrel – excess oxygen will accelerate material decomposition and carbon formation.
  • PF Grade works best if screen packs are removed. However, screens and dies may be left in place for purging with the Asaclean® PF Grade as long as the screen does not exceed 100 mesh (only 1 layer of mesh). Special procedures may be required to effectively clean extruders with vented barrels. If possible, plug the vents. If the vents cannot be plugged, contact Technical Service to discuss the most appropriate options.
  • While purging, it is recommended that a bucket of water be kept near the machine. Place Asaclean® purge piles in water immediately after coming out from the nozzle. 
  1. Upon completion of the production run, extrude the high heat resin from the machine, emptying the barrel. Clean the hopper and feed throat.
  2. Feed about 1 barrel capacity of the Asaclean® PF into the hopper, and increase screw speed to maximum safe level and make sure the purge pile appears clean. Asaclean® PF Grade should not be left in the barrel at temperatures above 370ºC (700ºF) for any period of time.
  3. Drop the temperatures in the extruder to below 370ºC (700ºF) – processing temps of 2nd resin
  4. When all temperatures are below 370ºC, stop screw rotation.

    Note: Do not allow Asaclean® PF Grade melt temps to drop below 280ºC (535ºF), or undue wear may be placed on the extruder drive.

  5. The processing temps of 2nd resin →280ºC -300ºC (535ºF-570ºF): When all temperatures are at proper temperature for the 2nd resin, begin feeding 2nd production resin. Once the next resin begins to extrude, increase screw speed to maximum safe level. Run until Asaclean® PF Grade is completely displaced. The processing temps of 2nd resin→180ºC -280ºC (355ºF-535ºF): When all temperatures are at 300ºC (570ºF), extrude Asaclean® PF Grade form the machine, emptying the barrel, as far as possible. And feed about 1 barrel capacity of the Asaclean® U Grade into the hopper. And keep the barrel full of Asaclean® U Grade. Drop the temperatures in the extruder to proper temperature for the 2nd resin. When all temperatures are at proper temperature for the 2nd resin, feed about 1 barrel capacity of the Asaclean® U Grade into the hopper and increase screw speed to maximum safe level and extrude Asaclean® U Grade form the machine, emptying the barrel, as far as possible. And feed 2nd resin and use low screw speed until the next resin starts coming out from the die, then increase to moderate screw speed until all of the Asaclean® U Grade is completely displaced.
  6. Return to production.

Technical questions?

To request detailed technical bulletins or technical support, contact us at Asahi Kasei Plastics North America Inc.

Phone: (800) 787-4348 / (973)257-1999
Fax: (973) 257-1011
Website: www.Asaclean.com
E-mail: sales@Asaclean.com

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