It is a casting process in which the pre-expanded polystyrene foam is used to produce a steel, castiron or non-ferrous casting of the exact same shape.
Together with lost-wax casting technique, lost-foam technology is a state-of-the-art method in the production of high-quality castings of complex shapes.
Casting produced using lostfoam technology
Expanded polystyrene – specified shape
Advantages of Lost Foam Technology
- Superior quality of surface finish and more precise tolerance levels for required specifications
- Complete elimination of foundry inclination
- Reduced machining allowance with the possibility of machining elimination (including the production of trapezoidal thread forms from the pattern)
- The lack of cores and defects resulting from core misalignment
- The lack of moulding flasks which eliminates the possibility of their misalignment
- Flexibility and freedom of casting design due to the possibility of gluing the expanded polystyrene components into models
- Technology optimization
- Ecological benefit - improved working conditions due to the lack of binders, resins and other additives, reduced industrial waste
Comparison of the Lost Foam Technology and Traditional Technology:
Stage 1 pre-expanded polystyrene
1. Polystyrene ESP is foamed in an expanded polystyrene foam machine.
2. Pre-expanded beads of polystyrene are injected into an aluminum mold, using compressed air.
3. Molded foam sections are then assembled into ‘clusters’, together with the gating system.
4. The assembled model is dipped in coating, which type depends on the target molten metal.
Stage 2 casting
5. After applying the coating, the expanded polystyrene model is placed into a flask with molding sand (without additives) and avacuum system.
6. The molten metal is poured into the foam model.
7. Knocking out castings from the casting mold
Polystyrene Foam Machine and Dryer
6 autoclaves of various sizes
Mixers for coatings
Induction furnace (2,5 tons)
Cast iron and steel castings
Induction furnace (0,65 tons)
Cast iron and steel castings
Gas furnace 200kg
Moulding line with moulding box (dimensions up to 1200x800mm)
Heat Treatment Furnace
Our bespoke services include machining and supply of the finished product to a client.
Grey Cast Iron
Ductile Cast Iron
and High-Alloy Steel
(copper and aluminium alloys)
- Casting weight from 0.3kg to 250kg
- Serial production and job production
- Manufacture from the customer-provided polystyrene
- Max casting dimensions 900x700x800 (length x width x height)
A casting used in a production line in the mechanical engineering industry.
- Rejection rate of 30%
- Foundry inclination up to 3 degrees
- High weight of casting
- Long machining time
- Low quality of surface finish in sand moulds
Through cooperation with the client’s process engineers and with the advantages of lost-foam technology in casting manufacture, the following improvements have been achieved:
- Lower wall thickness of casting
- Reduced machining allowance to 3mm
- Lost-foam technology eliminated defects resulting from misalignment and problems arising from foundry inclination
- Increased quality of the surface finish, up to the level requested by the client – CT8.