Extrusion & Post
14 visualizaciones
EVOH extrusion die drool carbon deposits
Fenómeno del problema
After EVOH extrusion shutdown, a brown carbon deposit layer is found on the die inner wall; after restart, black specks appear on the product surface
Análisis de la causa
EVOH is oxidized, decomposed and carbonized by prolonged heating in die stagnation zones; die not cleaned in time during shutdown; extrusion temperature too high accelerating carbonization
Solución
1) Flush the die with pure PE for 3-5min before shutdown to remove EVOH residue; 2) Disassemble and clean the die immediately after shutdown; 3) Reduce extrusion temperature by 5-10°C to reduce carbonization tendency; 4) Optimize die flow channel to reduce dead corners in stagnation zones
Conclusión clave
Die carbon deposits are caused by thermal oxidation and untimely cleaning; PE flushing and timely cleaning are key
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!