Investigation of micro lattice spiral wound membrane structures availing DLP and FDM techniques for water treatment

Abstract

This study addressed the challenge of reducing water contaminants using Spiral Wound Membrane (SWM) units in desalination and water treatment. Through additive manufacturing, we developed complex micro-lattice feed-spacer structures using FlexBLK 20, Pro-BLK10, ToughBLK 20, PLA, PETG, and ABS materials. The AHPTOPSIS statistical method indicated an ideal solution with Digital Light Processing (DLP) conditions showing a 20 μm layer thickness, FlexBLK-20 material, diamond structure, and for Fused Deposition Modeling (FDM) conditions, a 0.1 mm layer thickness, PLA material, and gyroid structure. Significant findings include a decrease in surface roughness by 79.67%–85.25% for DLP, an elongation increase of 50%–91.67%, and tensile strength improvement between 0.07%–40.83%. DLP printed feed spacers showcased better surface distributions than FDM, attributed to finer layers and higher density printing. Additionally, DLP printing resulted in a 32.02% increase in residual stress, suggesting superior compressive resistance. In thermal analyses, both DLP and FDM materials showed thermal stability up to 380 °C–450 °C. This research indicates that DLP printed feed spacers, with their enhanced properties, are potentially more efficient for water purification systems, providing smoother surface, better filtration, and increased durability.