Green Sand Versus foamcast Lost Foam Metal Casting Technology
| Property | Green Sand Casting | Foamcast Metal Casting Technology |
|---|---|---|
| Complex Internal Features and Part Consolidation. | Complexity determined by sand core limitations, geometry, strength, and cost. | Extensive and complex internal features (as thin as 3mm) available in foamcast, based on detail duplication and pattern assembly in foam. |
| Dimensional Tolerances | +/- 0.030" is typical depending on part size, complexity, and geometry | +/- 0.005"-0.010" is typical depending on part size, complexity, and geometry. |
| Surface Finish Capabilities | 250-600 microinches typical. Depends on grain fineness of sand. | 60-250 microinches typical. Depends on bead size and ceramic coating grain fineness. |
| Feature Accuracy | Core movement and shift between mold halves across the parting line limit feature accuracy. | No cores or mold halves to shift and degrade feature accuracy. |
| Parting Line and Draft Angles | Parting lines and draft angles are necessary for molding. | No parting lines in the mold and minimal draft on tools. |
| Environmental Costs | Sand recovery requires binder removal and time consuming sand clean-up | Sand is binder free, so it can be easily and rapidly recovered at low cost. |
| Tool Life | Wear on wood and metal tools from sand abrasion | Low wear and long life with aluminum tool |