Material Drying
12 visualizaciones
PA66 drying temperature upper limit 90℃
Fenómeno del problema
Pellets turn yellow and agglomerate after drying, injection molded products yellowish and more brittle
Análisis de la causa
Drying temperature exceeding 90℃ causes surface oxidation yellowing of PA66 pellets and even sticking; oxidation products also become triggers for subsequent degradation and color difference, over-drying damage is likewise irreversible
Solución
①Hot air dehumidifying drying strictly controlled at 80-90℃; ②yellowed pellets are judged over-dried and scrapped; ③if drying is not completed after 8 hours, lower to 70-80℃ for heat preservation while waiting for production
Conclusión clave
PA66 drying temperature upper limit 90℃ is stricter than PA6; what over-temperature brings is not more dryness but oxidative degradation, over-dried material can only be scrapped; after confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!