- molds and plastics  injection troubleshooter -

• Sticking in Core - plastic injection troubleshooter

• Description:

At end of cycle, the moulding does not release from the mould but sticks on the core (male mould side).

• Causes:
machine · injection pressure too high
mould · core too hot
· core bending
· creation of vacuum — especially on thin-walled parts

• Actions:

1st. check cycle time: cooling
2nd. decrease injection pressure
3rd. decrease injection hold time
4th. decrease second pressure time
5th adjust feed for constant cushion
6th decrease mould-closed time
7th increase core temperature
8th decrease cylinder and nozzle temperature
9th check mould for undercuts and/or insufficient draft
10th check mould for bending: rule of thumb is 1:5 for core diameter to core length

contact :  jmfalcao@webXpace.com

1998-2017  J.Falcao