Molds & Tooling
3 views
Excessive PPO Holding Pressure and Cooling Time
Problem Phenomenon
After conventionally extending holding pressure and cooling for PPO thick-walled parts, internal stress increases and demolding becomes difficult, and cycle efficiency is low.
Cause Analysis
PPO process characteristics require that holding pressure and cooling time cannot be too long; amorphous materials freeze quickly, and excessively long holding pressure has no feeding benefit and only increases stress; excessive cooling lengthens the cycle and wastes capacity.
Solution
①Limit holding pressure time to gate freezing; ②minimize cooling time according to demolding rigidity requirements; ③high-pressure high-speed injection combined with short holding pressure; ④verify dimensional stability through cycle optimization.
Key Takeaway
The short holding pressure and short cooling process orientation of PPO is opposite to that of crystalline materials; understanding the freezing characteristics of amorphous materials is key; cycle optimization cannot come at the expense of quality.; After confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence
Was this helpful?
0 people found this helpful
Thank you for your feedback!