Hopper design for piezo-actuated granular flow in powder bed 3D food printing

The flow properties of powders in hoppers are studied in order to make a design procedure for piezo-actuated hoppers that are used to deposit powder layers in multi-material 3D (food) printing. A commercial ring shear tester and an adjustable wedge hopper are used to perform measurements on various powders.

Continuum theories are applied to calculate suitable hopper parameters, specifically the orifice diameter and the wall angle, from these measurements. The results of these calculations are tested in conical hoppers. Measurements in a ring shear tester can be used for choosing a hopper wall angle, but not for choosing a hopper orifice diameter due to the propagation of large relative errors when calculating flow function parameters.

Measurements in an adjustable wedge hopper are suitable for picking a hopper orifice diameter if the powders are sufficiently fine and free-flowing. Reproducibility issues during measurements in the hoppers are addressed, and solutions to these issues are presented. Continue reading on the 3D food printing thesis

Hopper design for piezo-actuated granular flow in powder bed 3D food printing van Mastrigt, J. L. (Author). Oct 2020