Molds & Tooling
3 Aufrufe
PP Dimensional Post-shrinkage Drift
Problembeschreibung
PP parts continue shrinking 24~72 hours after demolding, causing precision assembly out of tolerance.
Ursachenanalyse
Semi-crystalline PP continues crystallizing and shrinking after demolding (post-crystallization), more obvious in high-temperature environments; inconsistent measurement aging may be misjudged as process fluctuation.
Lösung
①Extend in-mold cooling for more sufficient crystallization; ②appropriately raise mold temperature to promote in-mold crystallization; ③unify measurement aging (24 hours after molding); ④if necessary, anneal at 60~80℃ for 1 hour to accelerate stabilization.
Wichtigste Erkenntnis
PP dimensions should be managed by 'post-aging dimension'.
War das hilfreich?
0 Personen fanden dies hilfreich
Vielen Dank für Ihr Feedback!