| Possible Cause |
Possible Solution |
| Part is not sufficiently cooled. |
Reduce stock temperature.
Decrease second stage injection time.
Reduce injection pressure.
Reduce screw RPM.
Add decompression.
Increase overall cycle time.
Decrease mold temperature. |
| Mold design is incorrect. |
Seal nozzle correctly in sprue bushing.
Reduce length of sprue.
Increase draft on side walls of part
to assure smooth release.
Draw polish cavity surface in direction
of ejection. |
| Cores are too slender. |
Make cores stronger to prevent misalignment by the injection
pressure |
| Overpacking problem. |
Reduce injection speed.
Back off transfer point.
Reduce pack/hold pressure. |
