Vacuum seal molding process (also known as the V method of modeling) was invented in Japan in 1970s and successfully developed a special casting method. A single dry sand (do not add water, binder and additives) for sand, with plastic film after heating in a through hole and a suction device look like film forming, sealing the flask and rely on vacuum pump type air out, resulting in mold pressure difference inside and outside of dry sand get compactness, required to form the cavity of a physical modeling method.

Main procedure of V-process for coating, paint, filling sand compaction, film, these processes are to done in a vacuum. The basic equipment: belt of gas filter sand box template suction, suction vacuum system, plastics film heating, shaping and cutting, vibrating table, sand processing equipment.