Lost Foam Casting Process

The Lost Foam Casting Process is a technique that eliminates the need for sand binders and cores in casting. In this method, unbonded sand is utilized, and a foam pattern is employed to shape the casting. The process involves the following key steps:

Fill & Compact:
At the Fill & Compact process station, the foam pattern is "invested" into the sand. This allows the sand to fill all voids and support the external form of the foam pattern. The sand is introduced into the flask containing the casting cluster and compacted to ensure proper support for all voids and shapes

Pouring Operation:
The flask, now containing the invested foam pattern and compacted sand, is transported to the pouring operation. As metal is poured, the foam evaporates, enabling the metal to take the shape of the casting cluster.

Flask Dump Station:
Sand and metal separation occurs at the Flask Dump Station. Due to the absence of binders in the sand, this process is executed effortlessly. Systems can be designed to accommodate quenching operations if necessary.

Casting Finishing:
The casting cluster proceeds to the finishing area, where sprue, gate, and riser removal takes place. The reprocessing of sand through classification and cooling allows it to be reused. Thermal reclamation of the sand extends its useful life. Lost Foam offers both an environmentally friendly process and the advantage of more accurate casting.

Foam Pattern Creation:
Foam patterns are crafted from expanded polystyrene beads. These beads, initially hard granules similar in size and shape to sand granules, are expanded, stabilized, and molded into the desired shapes. Complex shapes may require the assembly of multiple patterns, which are then affixed to a central foam piece (tree). The assembled tree is dipped into a refractory coating to reinforce it. The strengthened tree, along with a pouring funnel (sprue), is placed into the flask.

Thraex Co. is globally recognized as the leader in lost foam technology, offering a comprehensive line of equipment for various stages of the lost foam process, including flask pouring, handling, and compaction, as well as foam bead processing equipment.

Lost Foam Advantages