Material Drying
2 views
EMA '2079851475616104452 Thick-Wall Bubbles
Problem Phenomenon
Dense bubbles of 0.1-0.5mm appear inside EMA injection molded thick-wall products, concentrated in the wall thickness center
Cause Analysis
Holding pressure insufficient <40MPa or holding time short, thick-wall center not compacted; raw material contains moisture; injection speed too fast, air entrapment; poor mold venting
Solution
1) Increase holding pressure to 60-80MPa; 2) Extend holding time to fully compact the thick wall; 3) Fully dry the raw material to moisture <0.02%; 4) Add vent grooves or vent pins to the mold; 5) Gradually decelerate injection to avoid air entrapment
Key Takeaway
Thick-wall bubbles are caused by a combination of insufficient holding pressure, moisture and poor venting
Was this helpful?
0 people found this helpful
Thank you for your feedback!