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Suggestions for Purging
Extruders- Remove die, adapters, clamp rings, breaker
plate and screen pack. OPENING MUST BE FREE OF RESTRICTIONS.
- Clean out all polymer from hopper.
- Keep barrel temperature at normal for purging polymer. Raise the extruder
temperatures to 450 F. Use 450-550 F when purging ABS, nylon, polycarbonate, PET
or other high temperature resins.
- Feed ULTIMAX PURGING COMPOUND into barrel, a small quantity at a time.
Run screw slowly. Do not use stuffer but allow compound to enter equipment by
gravity feed. If it doesn’t feed smoothly, raise temperature in increments of 10o F
until it does. Total purging compound should not exceed two pounds per inch of screw
diameter.
- When purging compound begins to drool out, increase speed of screw to
maximum.
- Minimize possible smoke and odor by purging in water.
- Continue adding purging compound until all polymer has been pushed out of
the equipment.
- Clean out all purging compound from hopper. Run screw dry. Slow screw
down.
- Clean end of screw and end of barrel.
- Remove screw from barrel. Screw can now be cleaned completely by wiping
with conventional means without scrubbing.
- Make sure all material is out of the equipment before actual shut down.
- Reassemble extruder.
Suggestions for Purging Injection Machines
- Remove nozzle. Nozzle opening should be at least 3/16” or remove
nozzle.
- Clean out all polymer from hopper.
- Keep cylinder temperature at normal setting for the polymer being purged.
Nozzle temperature should be left somewhat higher to avoid resistance flow.
- Reduce injection pressure to a minimum and increase as required.
- Feed small amount of ULTIMAX PURGING COMPOUND into cylinder, allowing
material to go through equipment by gravity feed. If it doesn’t feed smoothly, raise
temperature in increments of 10 F until it does. Normally, no more than one cylinder
full of purge material is sufficient to purge out old material and complete the
cleaning process.
- Minimize possible smoke odor by purging into water.
- Continue adding purging compound until all polymer has been pushed out of
the equipment.
- Clean out all purging compound from hopper.
- Now feed the next polymer. Set the temperature at normal for this molding
powder.
- Cycle slowly for first shot of this polymer. Then cycle rapidly to
eliminate purging compound completely from cylinder.
- Make sure all material is out of the equipment before actual shut down.
Note: Make sure workplace is well ventilated. Odors and fumes are not
toxic or harmful even if unpleasant to some.
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