Investigating the effects of Coating systems on the degradation behavior of 3D-Printed pressure vessels

This study investigates the long-term performance of 3D-printed pressure vessels subjected to accelerated aging through water mass infusion. Thermoplastic composites were used to construct the pressure vessels using Material extrusion 3D printing, and subsequent submersion in an ocean water solution at elevated temperatures was employed to simulate accelerated aging. The effectiveness of various coating systems in minimizing the long-term degradation of these 3Dprinted pressure vessels was also examined. Implosion experiments were conducted on both aged specimens with and without coating systems using a high-pressure tank facility. The results demonstrate that the application of polyurethane coating systems significantly slows the degradation process of 3D-printed vessels, with aged specimens exhibiting a reduced critical operational depth by 10.3 % compared to those without coatings. The pressure differential between unweathered specimens with and without coatings was 3.61 %, increasing to 23.3 % for weathered specimens. Coatings proved effective in reducing mass absorption and increasing critical collapse pressure. The analytical collapse pressure prediction closely aligns with experimental results, enabling performance generalization for other coating systems. This research contributes insights into the use of coating systems to enhance the longevity and performance of 3D-printed pressure vessels, highlighting their potential for mitigating degradation and improving structural integrity in long-term underwater applications.