Fehlruns
Fehlruns, or misruns, are a defect in casting and molding processes in which molten material fails to completely fill the mold cavity, producing an underfilled or incomplete part. The term is used in plastics injection molding, metal casting, and related processes; the resulting piece may be called a short shot.
Common causes include high material viscosity, insufficient processing temperatures, low injection or packing pressures, and short
Detection and assessment rely on visual inspection and dimensional checks; non-destructive testing such as X-ray or
Prevention involves process optimization: increasing melt temperature or reducing viscosity, adjusting injection speed and pressure, extending
Design changes to part geometry can reduce Fehlruns, including reducing extreme thickness variations, relocating or adding