Extrusion & Post
8 views
DSTDP extrusion melt fracture
Problem Phenomenon
DSTDP shows severe melt fracture when extrusion rate is too high, the extrudate is spirally twisted
Cause Analysis
DSTDP melt elasticity too high, elastic recovery at the die exit exceeds the critical value; die L/D ratio too short <10, melt not fully relaxed; extrusion temperature on the low side
Solution
1) Reduce extrusion rate to 2-3m/min; 2) increase die L/D ratio to 15-20; 3) raise extrusion temperature to 160-200°C; 4) add a small amount of low-elasticity resin to reduce system elasticity; 5) gradually converging die entrance design
Key Takeaway
Melt fracture is caused by elastic recovery exceeding the critical value; reducing speed and lengthening the die are the core countermeasures
Was this helpful?
0 people found this helpful
Thank you for your feedback!