Extrusion & Post
8 views
Poor thickness uniformity of PVA extruded film
Problem Phenomenon
Transverse thickness deviation of PVA extruded film ±15%, exceeding the ±5% industry standard
Cause Analysis
Unreasonable die flow channel design, causing uneven melt flow in the wide die; PVA melt elasticity large, uneven extrusion swell; air ring cooling uneven
Solution
1) Adopt coat-hanger die design to ensure uniform transverse flow; 2) Fine-tune die gap ±0.02mm; 3) Optimize air ring air volume and angle for uniform cooling; 4) Add a small amount of low-elasticity resin to reduce swell difference
Key Takeaway
Film thickness uniformity needs coordinated optimization from three aspects: die design, gap adjustment and cooling
Was this helpful?
0 people found this helpful
Thank you for your feedback!