Sticking in Sprue

Suggested Corrective Actions

Machine

  • Decrease injection booster time.
  • Decrease injection hold time.
  • Decrease injection pressure.
  • Increase cure time.
  • Increase nozzle heat.

Material

  • Increase lubricant level.
  • Reduce regrind level.

Mold

  • Align seating of nozzle to sprue bushing.
  • Ensure that orifice of nozzle is smaller that orifice of sprue bushing.
  • Increase taper of sprue bushing.
  • Inspect sprue for burrs, undercuts, or nicks.
  • Provide more adequate sprue puller.
  • Reduce stationary mold temperature.