Molding Process
8 visualizaciones
PA66 shrinkage rate 1.5-2%
Fenómeno del problema
Product dimensional deviation is large, sink marks are obvious in thick-wall areas, and shrinkage is inconsistent at different wall thicknesses
Análisis de la causa
PA66's semi-crystalline nature makes the shrinkage rate reach 1.5-2% with obvious directionality; the thicker the wall the more complete the crystallization and the greater the shrinkage, differential shrinkage between thick and thin causes warpage and dimensional out-of-tolerance
Solución
①Reserve allowance in the mold according to 1.5-2% shrinkage rate and correct by trial molding; ②Make wall thickness as uniform as possible and strengthen holding pressure in thick-wall areas; ③Lowering mold temperature and raising pressure can reduce shrinkage but internal stress warpage must be prevented
Conclusión clave
PA66 shrinkage rate ranks first among nylons; mold allowance reservation, wall thickness uniformization, and holding pressure compensation are the three axes of dimensional control; after confirming effectiveness, fix the parameters and practices into the work instructions to prevent recurrence
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!