Feb 2023 - Aug 2023

[DTU] Recoating Mechanism for High-resolution Vat Photopolymerization

Designed material recoating system for a vat photopolymerization printer for better print qualities

This is an individual research/engineering project completed in the Additive Manufacturing Lab at the Technical University of Denmark (DTU). The conclusion section of the project report is provided:

Challenges associated with printing metal or ceramic slurry in VPP printers with a bottom-up configuration have been identified, including insufficient self-recoating of the slurry at the curing surface and particle suspension sedimentation, both of which can compromise the structural and mechanical properties of the printed parts.

Through a comparison of various recoating mechanisms, such as tape casting, spinning vat, moving blade, and vibrations, the design of a moving blade system utilizing timing belt transmission has been selected as the preferred approach. Multiple design iterations have been conducted, resulting in a final design comprising an extended platform, a blade with changeable edge materials, and a blade and timing belt holder. The system is driven by a stepper motor and offers a compact, minimalistic design that can be easily integrated into the VPP platform alongside additional subsystems.

Methods for determining optimal recoating parameters and conducting mechanical tests have been proposed, which include utilizing a rheometer and printing disk and cylindrical specimens. These tests are planned to be conducted in future experiments. Other future objectives of the project include integrating the subsystem into the Amanda platform for synchronized and automatic recoating during the printing process, as well as developing a complementary slurry mixing and dispensing system.