Lost foam casting, also known as vacuum molding technology, which has studied and developed in Vietnam recently, however the Vietnamese product is still not good enough, the surface is quite rough, the quality doesn’t meet customer standard, specially oversea customer like Japan.
Lost foam casting (vacuum molding technology)
Lost-foam casting (LFC) is a type of evaporative-pattern casting process that is similar to investment casting except foam is used for the pattern instead of wax. Commonly cast metals include cast irons, nodular cast iron, steels, less frequently stainless steels and copper alloys are also cast. The size range is from 0.5 kg to several tons.
The first step of lost-foam casting is the creation of the foam mold. Next, the foam patterns are connected together as a cluster and the cluster is coated, also known as the refractory coating, via dipping, brushing, spraying or flow coating. After the foam mold is finished, it is buried in a container; for example, a metal drum; filled with compacted sand. The very ends of the foam shape are left exposed to facilitate the entry of the molten metal into the mold.
The benefit of lost foam casting is its ability to create casting with high dimensional accuracy, can limit the machining process. The excellent surface of casting as well as its exceptionally high dimensional accuracy are highly appreciated by the manufacturing companies.
The biggest advantage of lost foam casting method is can deliver complex castings with excellent ‘as-cast’ surface finishes that are dimensionally accurate, no machining.
