Extrusion & Post
1 views
Ejection Whitening and Mold Sticking in PE '2079851475616104452
Problem Phenomenon
PE products whiten at the ejector pin locations, or the product tightly wraps the core/adheres to the cavity, and is scratched and deformed during demolding.
Cause Analysis
PE has large shrinkage and strong clamping force on the core; small ejection area, insufficient cooling, insufficient draft angle, and excessive holding pressure all cause the ejection force to exceed the limit or demolding resistance to be too large; soft PE is also easily stretched and deformed during ejection.
Solution
①Extend cooling and lower the product temperature at ejection; ②Increase the number of ejector pins/enlarge the area or switch to a stripper plate; ③Reduce holding pressure to decrease the clamping force; ④Ensure sufficient draft angle and polish; ⑤Provide air intake for deep-cavity parts to prevent vacuum suction.
Key Takeaway
PE ejection whitening and mold sticking = 'large clamping force + concentrated ejection + insufficient cooling': first extend cooling, then distribute ejection, and finally reduce holding pressure; for soft PE, especially guard against 'stretching deformation upon ejection'.
Was this helpful?
0 people found this helpful
Thank you for your feedback!