Vacuum casting and lost foam casting is also called negative pressure casting. the biggest difference between Vacuum casting and traditional sand casting is that Vacuum casting don’t need binder.
Vacuum casting uses plastic film to seal up molding flask ,then , drawing-off air from mold by vacuum pumping system , pressure difference has been formed and makes dry sand closely knit , the needed cavity has been taken shape . Through core setting , mold assembling , pouring and vacuuming supply ,make the casting curdle , remove negative pressure ,next , the casting will be acquired with the molding sand scattering.
The advantages of vacuum casting : firstly , because it adopts negative pressure , so , the sand holes and air holes less , high compactness , surface smooth and bright , edge sharpness and size accurate ; secondly , energy conservation , efficient and cleaner production , dry sand can be repeatedly used because of no binder , the coal consumption reduces and power consumption increases , but ,it is broadly reducing the dust and noxious gas and saves the human resources ; in addition , Vacuum casting can also increase of the casting service life and is well thought of the user , becomes a new favorite in foundry industry.