- molds and plastics  injection troubleshooter -

• Pitting - plastic injection troubleshooter

• Description:

Pitting is the presence of unmelted particles due to difficult dispersion of additives, wrong mixing or crosslinking during processing.

• Causes:
machine · wrong or worn out screw, giving hang-ups
· melt temperature too low
· injection pressure too low
mould · shear in gating
· sharp corners
material · inhomogeneous material
· contamination

• Actions:

1st. get shear down
2nd. lower back pressure
3rd. decrease injection speed
4th. change temperature profile
5th check regrind percentage
6th check shot size vs part
7th check hot-runner: torpedoes

contact :  jmfalcao@webXpace.com

1998-2017  J.Falcao