Main molds and cores with appropriate mold properties are indispensable for realizing high-quality castings. Various types of sand are used in sand molding, and the properties of the molding sand for obtaining good sand molds are determined and controlled. Molding CAE is a quick and convenient means of determining the molding conditions. However, practical molding CAE tools have not yet been developed because the sand molding phenomena occurring in the blow molding process are very complex. Moreover, there is a need to consider the differences in sand properties.
In this study, blow molding experiments were conducted using several types of molding sands such as green molding sand with certain degree of compactability (CB Index), green sands with different sand particle components, and resin-coated sands (RCS) were prepared for the experiments. To obtain basic knowledge for the development of molding CAE, sand blowing phenomena were observed and the molding pressure waveform was analyzed. It was clarified that air has two types of effects in molding : transportation of sand particles and compaction of sand. The difference in sand particle movement between green sand and dry sand was also seen depending on the presence or absence of adhesive force. Based on these results, several governing equations for the development of molding CAE were proposed in this study.
