Key Notes for Flask Closing of Horizontal Molding Machines

Flask closing is the final critical procedure of molding. Improper operation easily triggers casting defects such as metal leakage, flask misalignment, sand inclusions and flask lifting. Operators must complete item-by-item inspections.

Before flask closing, verify accurate placement and smooth surface of cores; clean floating sand and debris inside flasks; confirm proper placement of auxiliary fixtures inside molds; ensure complete coating on gating systems and mold cavities; guarantee polished casting radii.

After flask closing, the parting surfaces of large and medium castings must be sealed to prevent molten metal leakage during pouring. Outer flasks and weighting irons shall be properly installed to resist buoyancy of molten metal and avoid flask lifting.

Operators shall not skip inspection steps. Standardized flask closing procedures can effectively reduce scrap rates of mass-produced castings and stabilize casting quality.