Molding flash is excess material attached to a molded product, which must usually be removed. This is typically caused by leakage of the material between the two surfaces of a mold. (This leak begins along what is called a parting line in mold design^[1]) Molding flash is seen when the optimized parameter on cull height is not calibrated.

Note: The excess material, commonly considered a quality defect in Semicon industries, is on occasion mistakenly described as 'flashing'.

References

1. ↑ SolidWorks Express | April 2002