Design of powder handling subsystem for multi-material binder jetting process

Abstract

This thesis presents the design of powder handling system in multi-material binder jetting (BJT) machine that allows material transition between layers. The system comprises three main subsystems, including one that contain the input feedstock, one that spread the powder across powder bed, and the build chamber where powder and binder are combined. The design of machine’s architect, chassis, and printhead subassembly were also mentioned in the implementation of the system.

This work’s process first covers the conceptualization of powder deposition technique, machine layout, and excess powder removal method. Then, detailed design phase was conducted, resulting a design of powder handling system in for BJT printer with build volume of 85 x 85 x 36.2 mm3. The machine uses single 25mm roller that can perform 5 different spreading techniques for wide variety of feedstock and application. Dual preheated powder reservoirs are deployed for faster binder curing. Excess powder is handled by combined motion of roller and build platform and is spread back to same-side overflow bin. A novel design of build chamber is also presented, offering the ability to transfer the printed part directly to the curing furnace.

The result design and the documented process can be used as groundwork for future design of similar system in powder-based additive manufacturing (AM) machine. This work can also be utilized as a blueprint for constructing an experimental setup, which, upon validation, could find applications in both research and industrial contexts.