Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Vacuum mold casting, also known as the V-process (vacuum molding process), is a specialized sand casting technique that uses vacuum pressure to hold dry, unbonded sand in shape around a pattern, eliminating the need for chemical binders.

How It Works

The process begins with a pattern (typically vented for vacuum draw). A thin plastic film is heated and draped over it, then a vacuum pulls the film tightly against the pattern. Dry, fine sand is filled into a flask over the film, and another vacuum compacts the sand firmly. The pattern is removed, the two mold halves (cope and drag) are assembled, and molten metal (often aluminum, but also ferrous/non-ferrous alloys) is poured while the vacuum is maintained. The vacuum holds the sand in place even as the plastic film vaporizes. After solidification, the vacuum is released, and the loose sand falls away, leaving a clean castin.

Key Advantages

A.Excellent surface finish and dimensional accuracy (tighter tolerances than traditional sand casting).

B.No draft angles required (due to the film's lubricity).

C.Environmentally friendly (no binders, reusable sand, minimal waste/fumes).

D.Thinner walls and lighter castings possible.

Limitations

A.Slower than conventional sand casting, better suited for low to medium volumes (e.g., 10–15,000 pieces/year).

B.Limited for highly complex internal cores in some cases.

This distinguishes it from urethane vacuum casting (a prototyping method using silicone molds and polyurethane resins under vacuum for plastic parts), which is a different process often simply called "vacuum casting" in rapid manufacturing contexts.Vacuum mold casting (V-process) is primarily used in foundries for high-quality metal castings with superior finish and precision.