Processing Machinery
1 views
PET sheet die lines and flow marks
Problem Phenomenon
Longitudinal long streaks and flow marks appear on the sheet surface; uneven gloss leads to downgrading
Cause Analysis
Die lip buildup scratches the melt surface to form die lines; unstable melt flow produces flow marks; impurities from damaged filter screens disturb flow uniformity; during on-site troubleshooting, verify item by item according to this mechanism, and avoid blindly adjusting the machine based only on experience
Solution
① Regularly clean die lip buildup with a copper scraper; ② improve filtration performance; ③ keep extrusion pressure and temperature stable; after adjustment, continuously sample to verify the effect, and resume mass production only after confirming stability
Key Takeaway
Die lines are a chronic appearance disease of PET sheet; frequent die lip cleaning plus stable pressure and temperature, together with intact filter screens, can maintain a mirror surface; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence
Was this helpful?
0 people found this helpful
Thank you for your feedback!