(233d) Modeling of Simultaneous Deposition of Powder in Three Parallel-Oriented Cylindrical Dies

Although the process of powder deposition into multiple dies is of critical importance to industry, it remains to be systematically examined in its entirety. To date, no models or methods published can be used to study or simulate the feed shoe filling process involving a large number of 3D particles of various shapes and sizes. In order to further the understanding of the die filling process, the second generation pressure deposition tester (PDT-II) was used to investigate simultaneous deposition of powder by feed shoe in three parallel-oriented cylindrical dies. In PDT-II, a pressure sensor strip was used to measure real-time pressure distribution values at the bottom of the dies for an industrial powder mixture. The powder was deposited into the dies at different feed shoe speeds. A computational model was developed to simulate powder pressure increase during the deposition process. At lower feed shoe speeds (20 and 100 mm/s), the entire pressure increase profile was partitioned into 10 distinct stages of filling. Each stage was modeled by a curve or a straight line, based on physics of the filling process. Most of the powder (about 84.9% at 20 mm/s and 93.5% at 100 mm/s) deposited at an almost constant filling rate within a very short time in the beginning of the forward stroke. This short time period deposited about 80% (in 1.3 s at 20 mm/s feed shoe speed) and 90% (in 0.3 s at 100 mm/s feed shoe speed) of the total powder mass during the entire filling cycle. The computational model calculated values were in good agreement with measured values.