Extrusion & Post
8 views
PVC Film Gel and Specks
Problem Phenomenon
Calendered/extruded PVC film shows gel spots and crystal spots, printing and lamination affected.
Cause Analysis
Uneven plasticization, poor stabilizer dispersion or degradation cross-linking; burnt material brought out from equipment dead corners; film is thin, any non-uniformity shows; during on-site troubleshooting, verify item by item according to this mechanism, avoid blindly adjusting the machine based solely on experience.
Solution
①Strengthen plasticization and dispersion, ensure melt uniformity; ②Clean retained material in equipment dead corners; ③Check whether stabilizer dispersion is uniform; ④Densify screen pack to intercept impurities and gel; ⑤Control regrind proportion and re-dry.
Key Takeaway
PVC film surface spots = 'plasticization + dispersion + dead corners': plasticization and additive dispersion are the main line, dead corner burnt material is the hidden danger; film has the highest uniformity requirement, plasticization must be excessive.
Was this helpful?
0 people found this helpful
Thank you for your feedback!