1997 Volume 69 Issue 2 Pages 147-153
Recently, the green sand molding process by means of the air-flow + squeeze (flask type) is being used. In this study, the air-flow stage is investigated. It is essential to know how sand particles are moved by air pressure. Numerous experimental studies have been conducted, but none have clarified the behavior of sand particles, nor optimized the molding process. The purpose of this study is to develop a process model using the distinct element method (DEM). In this model, the individual particles are moved by three forces, namely, contact force, drag force and gravitational force. Numerical simulation was performed to predict the behavior of the sand particles during the air-flow stage, and laboratory experiments were carried out to examine the calculated results. From the simulation, contact force, drag force and inertia force of individual particles were obtained as the function of time. The inlet air velocity was seen to affect the phenomena of molding sand compaction. This study applying DEM, produced useful information such as the effective molding parameters for the optimization of the air-flow process.
