Modelling is one of the leading process in sand, generally divided into two categories: manual and machine model. Manual models are used for single piece or small batch production. Machine models are used for mass production. In the mold cast, manual modeling method is flexible and varied, mainly including whole mold cast, parted pattern casting, dig sand molding, live piece molding and scraper molding.
The full pattern molding takes the shape as a whole. When the pattern is put inside a, the parting surface is flat. Such process among most process of mold cast is relatively simple, the cavity shape and dimensional accuracy is preferable. It applies to the castings whose outline shape section at the top is the large with simple shape, such as gear billet, bearings. As for the parted pattern molding, the two separate models are respectively in the up and down side cavity when modelling. And the parting surface is flat. The molding operation is almost the same as the full pattern molding. Parting modelling is simple and widely used, mainly in the castings without flat surface and castings with the maximum cross-section in the central part, such as sleeve, pipe and castings with complex shape.