Direct Ink Writing Using Agar-based Ink in 3D-printing of Al2O3 Membrane Support with Tubular Shape

Abstract

The forming technique of tubular alumina membrane from agar by using 3D printing technology on direct inking technique is a process to reduce the cost and environmental friendliness. Alumina ceramic ink for 3D printing was prepared using TM-5D type of alumina powder with a particle size of 0.2 µm at a solid ratio of 80 wt%. The agar solution at concentrations of 1, 2, 3 and 4 wt% were analyzed the viscosity and gelation temperature were. Preliminary results show that 4 wt% concentration of agar solution is optimum for 3D printing. However, the further improvement of the rheological properties is required by adding 10 wt% of polyethylene glycol 1500 and hydroxyethylene cellulose (HEC) at 0, 1 and 2 wt% into agar solution. The results showed that 2 wt% of HEC-added in alumina slurry inks provided the appropriate viscosity for 3D printing with perfect filament. In addition, it was found that adding acetone at 0, 10 and 20 wt% were improved the ink rapidly dry after extrusion through the nozzle. After drying the specimens at room temperature for 24 hours and then sintering at 1350oC, it was found that the amount of acetone affecting the apparent density of the printed alumina membrane tubes was 3.82. 3.99 and 4.03 g/cm3 when 0, 10 and 20 wt% of acetone were added, respectively. This study indicated that agar-assisted alumina slurry inks had potential for 3D printing to use as a binder for forming the tubular alumina membranes with 3D printing technology. However, the research team plans to improve fidelity in the future.