American Foam Cast: Lost Foam Casting
Lost Foam Casting is a unique technique in metal casting–and it’s our specialty here at American Foam Cast. This type of casting is excellent for improving project efficiency, putting more function into a single casting, and eliminating wasted movement and resources.
Using our expertise in Lost Foam casting, we’ve expanded the applications and functions of this technique. We offer our customers the ability to design more features into fewer parts, often fitting an entire design into just a single casting that would have typically required multiple castings and subsequent assembly. This leads to higher long-term production costs and a streamlined production process.
What is Lost Foam Casting?
Lost Foam Casting, also known as the expanded polystyrene casting process, is a highly sophisticated, cavity-less casting method developed in 1958. Molten aluminum is poured into the foam cast using an expanded polystyrene (EPS) foam mold supported by sand. The sand is packed on all sides, leaving room for the molten metal to be poured in. The heat causes the foam to evaporate, shaping the casting within the mold and leaving behind the desired shape.
The Advantages of Lost Foam Casting
There are many advantages to choosing lost foam casting over conventional metal casting, especially when you partner with American Foam Cast. We can bring to life elaborate and complex designs that aren’t typically manufacturable through other means. Lost foam also reduces material waste and requires less energy to operate compared to other types of casting, making it a much more economical decision in the long run despite a comparatively higher upfront cost.
The Lost Foam Process
- Pre-expanded polystyrene beads of a controlled density are allowed to stabilize and reach a predetermined pentane level.
- A foam pattern is created by blowing pre-expanded polystyrene beads into an aluminum mold. The mold is then heated with steam, causing it to expand and fuse with the beads. The tool is then cooled to stabilize the foam pattern.
- After being subjected to an elevated temperature for several hours to shrink the parts to a stable size, the pattern segments are precisely bonded together with a hot melt adhesive into a single cluster.
- This cluster is dipped into a refractory coating, completely covering the patterns and gating system. It is then dried in an oven.
- A loose, unbonded molding media, synthetic mullite, is packed around the cluster with the aid of vibration. Synthetic mullite is much safer for the environment and results in castings with significantly better dimensional accuracy and far less risk of breakdown than silica sand—a fact demonstrated by the LFC/ UAB research.
- Molten Metal is poured directly into the foam cluster, displacing the foam and replacing it with metal.
- Once casting is complete, the finished metal part undergoes final finishing.
Ready to Get Started?
Established in 1997, American Foam Cast is an ISO 9001:2015 manufacturer specializing exclusively in lost foam casting. If you’re interested in our services, don’t hesitate to contact us today to request a quote or with any questions you may have.