Injection Molding
7 visualizações
PMMA Stress Cracking
Fenómeno do problema
Products crack during assembly, solvent contact or after storage, often starting from sharp corners and screw bosses.
Análise das causas
PMMA is brittle and sensitive to residual stress; high stress from fast injection, cold demolding, sharp corners and press fits cracks under solvent or load.
Solução
①Slow injection; ②Sufficient cooling and gentle demolding; ③Change sharp corners to rounds (25%~60% of wall thickness); ④Anneal at 70~80℃ for 2~4 hours; ⑤Avoid contact with incompatible solvents.
Conclusão principal
PMMA delayed cracking = the delayed detonation of internal stress, annealing is the insurance.
Isto foi útil?
0 pessoas acharam isto útil
Obrigado pelo seu comentário!