Blow Molding
2 views
Severe Parison Sag in PU Extrusion '2079851475616104457
Problem Phenomenon
PU extrusion '2079851475616104457 parison sag 20-40mm, causing bottle bottom wall thickness only 0.3-0.4mm
Cause Analysis
PU melt strength low, parison stretched thin under gravity; parison extrusion speed slow increasing sag time; parison temperature too high, viscosity low, aggravating sag
Solution
1) Add slight crosslinking agent 0.3-0.5wt% to increase melt strength; 2) Increase parison extrusion speed to shorten sag time; 3) Reduce 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; slight crosslinking and wall thickness control are key
Was this helpful?
0 people found this helpful
Thank you for your feedback!