The Lost Foam casting process (LF casting process) is a sand casting process for the production of especially complex metal components where other casting processes failed or only lead to unsatisfactory results. The LF casting process enables the production of prototypes as well as small or large series. Components can be realized in steel, cast iron, aluminium and copper alloys.
First of all, a polymer foam pattern of the component is embedded in binderless molding sand. Molten metal is added, which combusts the pattern and then replaces it. The result is an accurately detailed, ready to use metal copy of the pattern. The “loss” of the pattern due to combustion gives the Lost Foam process its name. Find more information on the process sequence here.
New horizons for designers
For designers, the LF casting process offers unique freedoms in design, because the polymer foam patterns can be composed of several parts and allow for significantly more complex constructions than other molding tools. In that way, burrless forms are produced in only one cast. Otherwise, they would have to be assembled from several cast parts. This for example enables the integration of undercuts and finest ducts.
The diverse possibilities require a diverse know-how from the construction of the patterns to the actual casting. The Lost Foam Council e.V. helps you to develop and enhance this knowledge.
History: The development of the process
The Lost Foam casting process is an advancement of the full-mold casting process from the USA, which has already been known since the 1950s. The full-mold casting enabled the cost-effective production of single parts. Disadvantage: It was not apt for series production. Thanks to comprehensive further developments, large series are possible today with the LF casting process.
One major step of development was the use of binderless sand (1960). Thus, today, the use of binderless sand in Lost Foam and bonded sand in full-mold casting is the distinguishing criterion of the two processes. Further important developments: the dry-sand molding process (1964), the magnet molding process and the vacuum full-mold casting process (1968). In Germany, the first extensive use of the Lost Foam casting process was reported in 1975 in the production of fuel separators (HAH, FAH-1).