Extrusion & Post
3 visualizaciones
HDPE Melt Fracture Sharkskin
Fenómeno del problema
Extruded product surface shows periodic rough texture like sharkskin, with loss of gloss
Análisis de la causa
When HDPE extrusion speed exceeds the critical shear rate, the melt surface fractures; low die lip temperature increases melt viscosity and wall shear stress, making sharkskin appear earlier
Solución
①Reduce extrusion speed below the critical shear rate; ②increase die lip temperature to reduce wall shear stress; ③add fluoropolymer processing aid to promote wall slip; after adjustment, continuously sample to verify the effect, and resume mass production only after confirming stability
Conclusión clave
Sharkskin is a shear critical phenomenon in HDPE extrusion; reducing speed, increasing mold temperature, and adding PPA work together; after confirming effectiveness, solidify the parameters and practices into the work instruction to prevent recurrence
¿Le ha resultado útil?
0 personas encontraron esto útil
¡Gracias por sus comentarios!