Blow Molding
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CEF extrusion '2079851475616104457 parison sag severe
Problem Phenomenon
CEF extrusion '2079851475616104457 parison sag 20-40mm, resulting in bottle bottom wall thickness only 0.3-0.4mm
Cause Analysis
CEF melt strength low, parison stretches and thins under gravity; slow parison extrusion speed increases sag time; parison temperature too high, low viscosity aggravates sag
Solution
1) Add micro-crosslinking agent 0.3-0.5wt% to improve melt strength; 2) Increase parison extrusion speed to shorten sag time; 3) Lower parison temperature by 10-15°C to increase viscosity; 4) Wall thickness controller to compensate sag
Key Takeaway
Parison sag is caused by low melt strength, micro-crosslinking and wall thickness control are key
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