Processing Machinery
1 views
Excessive Shear from PSU Screw Speed
Problem Phenomenon
After increasing screw speed to improve plasticization, PSU shows shear overheating and degradation; the medium speed requirement was ignored; product performance declined.
Cause Analysis
PSU screw speed is recommended at medium speed to prevent excessive shear, recommended 45~55; high-viscosity melt generates significant shear heat; excessive shear breaks molecular chains.; During on-site troubleshooting, verify item by item according to this mechanism, avoiding blindly adjusting the machine based solely on experience
Solution
①Control screw speed in the 45~55 medium range; ②Prevent excessive shear; ③For insufficient plasticization, prioritize raising temperature rather than speed; ④Monitor measured melt temperature.; After adjustment, continuously sample to verify the effect, and resume mass production only after confirming stability
Key Takeaway
The 45~55 for PSU screw speed is the quantitative definition of medium speed; shear heat management is a common topic for high-viscosity materials; measured temperature is the referee.; After confirming effectiveness, solidify the parameters and practices into the work instructions to prevent recurrence
Was this helpful?
0 people found this helpful
Thank you for your feedback!