| Possible Cause |
Possible Solution |
| Mold is not packed enough. |
Increase overall injection speed.
Increase boost cut off set point.
Increase hold pressure and temperature.
Increase cushion in cylinder.
Increase shot size.
Increase barrel heating.
Increase back pressure.
Add or increase nozzle heating. |
| Mold function is incorrect. |
Be sure gates are large enough
and are correctly located.
Reduce length of sprue bushing, increase
bushing diameter.
Increase mold temperature.
Make sure vents are large enough and are clear.
Increase mold cooling cycle time. |
| Part design is incorrect. |
Redesign part to remove sharp thickness
changes in section. |
