Optimisation of binder content for extrusion-based 3D printing of porcelain and alumina ceramic structures through layer quantification

Achieving optimal binder content ensures the printability and structural integrity of ceramic parts fabricated through extrusion-based 3D printing. This study systematically investigates the influence of polymer binder concentration on the layer deposition efficiency and shape fidelity of 3D-printed porcelain and alumina structures. A series of formulations with binder content ranging from 0.67 wt.% to 5.33 wt.% were analysed, with the number of successfully deposited layers serving as the key quantification parameter. Results indicate that a binder content of 2 wt.% provides the most favourable balance between extrusion stability, interlayer adhesion, and self-weight resistance, enabling the deposition of up to 25 layers in porcelain and 56 layers in alumina for a 100 mm thin wall structure. Lower binder concentrations led to intermittent flow and premature collapse, while higher binder contents resulted in increased viscosity, flow interruptions, and surface defects such as cracking post-drying. This study highlights the critical role of binder optimisation in achieving high-quality ceramic structures and provides insights into mitigating key process limitations in extrusion-based additive manufacturing.