Injection Molding
7 visualizaciones
Severe internal stress birefringence in PET injection molded parts
Fenómeno del problema
Transparent PET products show dense colored fringes under a polariscope, indicating a high internal stress level.
Análisis de la causa
Fast filling speed causes high molecular chain orientation that is not fully relaxed; mold temperature is low; cooling rate is too fast.
Solución
Reduce injection speed; increase mold temperature to 140-160°C; extend cooling time; anneal to eliminate stress.
Conclusión clave
PET birefringence is the optical manifestation of internal stress, especially important for optical-grade PET.
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!