Processing Machinery
3 Aufrufe
COC Grade Switchover Cross Contamination
Problembeschreibung
After switching production between COC grades with different Tg, the products show turbidity, streaks and performance fluctuations, and it takes a long time of purging to restore purity.
Ursachenanalyse
Grades with different Tg have large differences in processing temperature; residual high-temperature grade material does not melt under low-temperature processes, and residual low-temperature grade material degrades under high-temperature processes; incomplete barrel replacement forms cross contamination.
Lösung
①When switching grades, fully purge and replace at the new grade temperature; ②pay special attention to residual unmelted particles when switching from high Tg to low Tg; ③disassemble and clean the screw if necessary; ④record and standardize the switchover cleaning duration.
Wichtigste Erkenntnis
The core of COC grade switchover is temperature difference management; the material change direction determines the risk type; standardized cleaning processes avoid human arbitrariness.; After confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence
War das hilfreich?
0 Personen fanden dies hilfreich
Vielen Dank für Ihr Feedback!