Processing Machinery
2 Aufrufe
PBT Black Specks and Burning
Problembeschreibung
Black specks and burnt streaks appear on the product; cleaning the barrel improves it for a short time but it recurs
Ursachenanalyse
PBT degrades when the barrel temperature exceeds 275°C or the residence exceeds 30 minutes; a low nozzle temperature causes the sprue to solidify and block the nozzle, leading to local overheating; recycling the sprue of flame-retardant material and glass fiber material also introduces degradation products
Lösung
①Control barrel temperature and residence time; ②Appropriately increase the nozzle temperature to prevent solidification and nozzle blockage; ③When shutting down, promptly clean the barrel with PE or PP; after adjustment, take samples continuously to verify the effect, and resume mass production only after confirming stability
Wichtigste Erkenntnis
PBT black specks and burning are investigated along three lines: temperature, residence, and nozzle; PE/PP cleaning at shutdown is an iron rule to prevent carbonization; after confirming effectiveness, solidify the parameters and practices into the work instruction to prevent recurrence
War das hilfreich?
0 Personen fanden dies hilfreich
Vielen Dank für Ihr Feedback!