Uniformity evaluation of different filling methods for deposition of powders in containers

Study of the particulate material deposition into containers and bags represents a critical step in numerous industrial processes. However, there are no systematic investigations wherein different methods have been compared. Herein, results from an experimental study dealing with filling of powders into shallow cavities (aspect ratios less than 0.25) are presented. An innovative rotational rainy filling device was designed and fabricated. This versatile device can be used to evaluate fill uniformity for various die shapes, deposition rates, and deposition heights. In this research, the rotational rainy and feed shoe fill devices were used to investigate the uniformity of powder deposition in a rectangular shallow container. The test material used in these studies was BPM, an industrial powder. For rainy fill, based on the quantity of powder weight deposited in six equi-sized 13.43 mm x 13.43 mm compartments at RPMs of 1 to 10 resulted in highest and lowest COVs of 39.51 % and 9.11 % at RPMs 3 and 7, respectively. The pressure distribution profiles using the PDT-II corroborated this observation, i.e., the COVs at RPMs 3 and 7 were 29.0 and 20.7%, respectively. With feed shoe as the powder deposition method, pressure distribution profiles had uniform distribution in the mid-portion with higher values along the upper side of the die. The COV of pressure distribution profile was 14.7%. Generally, the feed shoe fill resulted in higher pressures (mean=301 Pa) compared with rainy fill (mean=204 Pa) by 47.5%.