Molds & Tooling
7 visualizaciones
PMMA Sink Mark Depression
Fenómeno del problema
Sink marks appear at thick-wall areas and behind ribs; sink marks on transparent parts are also accompanied by abnormal light refraction.
Análisis de la causa
Uneven wall thickness causes insufficient feeding compensation when thick areas shrink; insufficient holding pressure or time, or gate freezing too early, all prevent PMMA's relatively large shrinkage from being compensated.; During on-site troubleshooting, verify item by item according to this mechanism to avoid blindly adjusting the machine based on experience alone.
Solución
①Increase holding pressure and time; ②core out thick areas, uniformize wall thickness; ③enlarge gate and runner; ④adjust mold temperature to improve feeding compensation.; After adjustment, continuously sample to verify the effect, and resume mass production only after confirming stability.
Conclusión clave
PMMA sink mark treatment follows the feeding compensation logic; sink marks on transparent parts also have optical effects, and structural uniformity is more reliable than process compensation.; After confirming effectiveness, fix the parameters and practices into the work instruction to prevent recurrence.
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!