Additively Manufactured Fixtures for Flow-Through Coating of Pressure Vessels

Additive manufacturing is ideal for creating complex fixtures for early-stage research and development. For one such effort focused on electrodeposition of pressure vessels with ternary mixtures of ionic liquids and water, various fixture designs were produced that alter the turbulent flow characteristics of dense ionic fluid. Their primary function was to observe how the angle and number of channels within the fixture affected the coating application to the substrate, and to serve as a centering device for a tensioned through-vessel anode. The fixtures needed to attach at each end of the pressure vessel and survive under compressive load and extended periods in the caustic environment of the electrolyte composition.
In order to manufacture the prototypes quickly for benchtop testing, Fused Filament Fabrication (FFF) with Acrylonitrile Styrene Acrylate (ASA) material was initially chosen but ruled out due to the inability to print finer internal details of the fixture. Due to system availability and material constraints requiring some chemical resistance, it was then decided to try digital light processing (DLP) and stereolithography (SLA) to meet the design tolerancing. Three candidate materials were tested including Nexa3D xPRO410 acrylic, Nexa3D xPEEK147, and FormLabs Rigid10K resin. This presentation will go over the design methodology, material processing, application, and testing results of the fixtures for flow-through coating of open-ended pressure vessels.