After the mold was finished, the foam company will make lost foam (polystyrene) patterns, then casting company will do coating outside the patterns, then the patterns are simply put into the mold cavity, after which molten metal is added. The heat from the molten metal will cause the foam patterns to vaporize, resulting in the creation of a casting that can be ejected the mold cavity.
Another 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. Let's say if you produce a complex shape in by sand casting, after taking out casting, you have to put it in machinning, remove an excess metal, polish the surface; now with lost foam casting, you just take the casting out, remove the raiser and feeding system, just all, no need to put more machining. As you might know the cost of machining is not really cheap.
On other hand, when compared to other casting processes, the molds used in lost foam casting cost more than those used in other casting processes. However, the most important thing is the weight of product in lost foam casting can be reduced and lighter than product of other processes, which can help to cut down the material. In summary, the products manufactured by lost foam casting offers a number of advantages and are appreciated one of modern technologies in foundry industry.