Processing Machinery
2 views
Screw seizure of PET extruder
Problem Phenomenon
The screw cannot rotate (seizes) when restarting after a shutdown during PET processing.
Cause Analysis
The material is not fully purged at shutdown; after cooling, PET crystallizes and solidifies between the screw and the barrel, locking the screw.
Solution
Before shutdown, purge and replace PET with purging material or PP; shut down after the barrel cools down; before startup, first heat to processing temperature and hold for 30min.
Key Takeaway
PET screw seizure is a serious equipment accident and can be avoided with standardized shutdown procedures.
Was this helpful?
0 people found this helpful
Thank you for your feedback!