Molds & Tooling
8 visualizaciones
Melt Fracture Surface Defect of PEEK
Fenómeno del problema
During high-speed filling of PEEK, sharkskin-like or bamboo-node-like rough texture appears on the product surface; reducing speed improves it, but thin-wall parts then face the short shot contradiction.
Análisis de la causa
When the melt passes through the gate or die lip, the shear rate exceeds the critical value and the surface melt fractures; PEEK's high viscosity makes the critical shear rate relatively low, so high-speed filling triggers it more easily.
Solución
①Use multi-stage injection — decelerate in the gate area and accelerate in the filling area; ②Enlarge the gate to reduce the shear rate; ③Appropriately raise the melt temperature to lower the viscosity; ④Switch to a lower-viscosity grade if necessary.
Conclusión clave
The core of PEEK melt fracture treatment is local shear rate control; multi-stage injection is the standard means to balance filling and surface quality; gate size is the key design variable.
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!