Material Drying
2 views
PA66 internal stress cracking
Problem Phenomenon
PA66 assembled parts crack at the screw boss root after being placed for several weeks
Cause Analysis
Molding internal stress concentrates at wall thickness abrupt changes, and superimposed assembly stress causes delayed cracking; internal stress release after PA66 moisture absorption also induces it; during on-site troubleshooting, verify item by item according to this mechanism, avoiding blindly adjusting the machine based only on experience
Solution
Structural rounding; raise mold temperature to reduce orientation stress; moisture conditioning after molding; assembly torque specifications; after adjustment, take continuous samples to verify the effect, confirm stability before resuming mass production
Key Takeaway
Delayed cracking requires prevention in three aspects: structure, process, and assembly; after confirming effectiveness, fix the parameters and practices into the work instructions to prevent recurrence; include this case in the defect archive as a troubleshooting reference for subsequent similar problems
Was this helpful?
0 people found this helpful
Thank you for your feedback!