1. Description and classification of molding processes

Very schematically, the molding processes used can be classified according to the mold's ability to produce a single part or a large number of parts, i.e. :

• non-permanent mold (destroyed with each piece) ;

• permanent mold (reused many times).

For this second category, mold elements can be replaced for each part, as in the case of the sand cores used to shape the recesses.

Combined with the two previous criteria, another important criterion for refining the classification is the pressure or depression applied during solidification of the part.

• The model, i.e. the replica of the final part, can be either destructible or permanent. In the former case, the pattern can be gasified during metal casting (Lost...