1. Evaporative Pattern Casting Process is Friendly to the Environment
The most important environmental impacts during foundry are the large use of energy and all kinds of emissions and dust.
The process has tremendous advantages for the production of castings which require complex cored passageways, uniform wall thickness and limited or no draft angles. As the casting is a virtual reproduction of the molded foam pattern, dimensional control is improved over castings produced by the green-sand route and for many features such as gasket surfaces and drilled holes. Furthermore, the improved dimensional control means a significant reduction in, or even the elimination of, machining. And this means a reduction in the use of coolants and lubricants, the largest environmental impacts in the metal industry!
The process differs from other techniques primarily in the following areas:
· There are no cores and no parting lines,
· Dry un-bonded sand is used,
· There is no mold wall movement and
· The tooling is not subjected to foundry wear.These differences result in the following advantages of foam cast over conventional foundry processes:
· There is less energy needed;
· There are lower emissions, the waste is solid and relatively clean, and the sand is easily recycled;
· Complex shapes are possible and the surface is almost finished. This means that there is less or no machining, less or no finishing and less or no assembly needed;
· The financial advantages are that there is less labour needed & the lifetime of tools is extremely long.
· Concerning the core: there are no related defects, shifts or fins, there is no core removal and there is no core equipment necessary, so no handling of hazardous core materials;
· Due to the close dimensional tolerances and the possibility of complex shapes, the design freedom is larger;
· The employees'/workers' working conditions are improved.
2. Evaporative Pattern Casting Process capability:
Casting Alloys:
Cast Iron – Grey Iron, Ferrite/Pearlite Ductile Iron, High-Nickel Ductile Iron, Hi-Chrome White Iron
Cast Steel – Carbon Steel, Tool Steel, Hi-Manganese Steel, Heat-resistant Steel
Non-ferrous – Aluminum alloy, Bronze, Brass
Process Capability:
Weight: 15–2 500 kg
Size: ≤1 200 mm
Linear Tolerance: ISO 8062 CT6–9
Wall Thickness: ≥3 mm
Sharpness (min. radius): R0.5
Surface Finish:
– Non-ferrous: Ra 3.2–6.3 µm
– Ferrous: Ra 6.3–12.5 µm
3. Benefits
- Foam patterns allow large, near-investment-quality castings without limits on section thickness or weight.
- Ceramic cores can be embedded in foam to create complex internal geometries and cut drying times.
- EPS patterns weigh ≈90 % less than wax; shells are 30–50 % lighter than investment shells.
- Dimensionally stable at elevated temperatures, foam patterns shorten shell-drying and overall lead times.
- Shells are poured cold; steeper thermal gradients yield high-integrity castings.
- Unique polymer binders break down more easily than standard investment ceramic, simplifying cleaning.
- Foam can be molded complete with the gating system, saving assembly labor.
- Surface finish and dimensional tolerances approach those of investment castings.
- Heavier castings are feasible, depending on geometry and equipment capacity.