Melt Blocking
Vol. 23 #1, May 1996
Whenever starting up an extruder, after the extruder has gone through the proper soak time, turn the screw speed up to about 10 rpm and then open the slide gate and introduce the resin to the screw. This will help eliminate the resin from sticking to the screw root.
Then during shut down the opposite is true. Before stopping the screw rotation, close the slide gate and let the screw turn at about 10 15 rpm until the drive load drops off to the minimum load. This will be the evidence that the resin has been purged from the feed section of the screw.
This purging will eliminate the possibility of a melt blocking burning the next start up.
See also:
- Melt block problems
- Purge 2
- Start up efficiency
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