Parting-line Flash: Guide for Avoiding
A phenomenon in which the resin squeezes out and solidifies on the parting line of the mold.
- There is a gap in the mold
- Foreign matter is attached between the mold plates
- Rising internal pressure(insufficient vent)
- High injection pressure
- Insufficient mold clamping force
- Large material supply
- High resin temperature
- Long injection pressure retention
- Fast injection speed
- Eliminate mold gaps
- Clean the mold
- Attach a gas vent to the sprue and runners
- Degas just below the sprue part and at the runner end.
- Increase the air vent near the final filling part of the product part.
- Lower injection pressure
- Increase mold clamping force
- Proper supply amount
- Adjust the cylinder temperature to an appropriate temperature
- Make the pressure holding time appropriate
- Slow the injection speed
- By increasing the number of vents, the internal pressure is reduced and burr is prevented.
- By taking good venting measures with the mold, there is no air resistance in the mold and molding at low pressure is possible.