A Comprehensive Rheological and Texture Protocol to Optimize an Extrusion-Based 3D Printing Process

Extrusion-based (EB)-3D printing (3DP) holds promise for personalizing pharmaceutical and cosmetic products, yet faces challenges in adjusting the printer settings, requiring robust optimization and characterization protocols. This study aims to develop a protocol based on rheological and texture analysis to characterize flow behaviour and optimize gelatin inks' printing settings. A gelatin-based ink with printable properties was developed and analyzed using a Kinexus Lab + Rheometer for gelation temperature and viscosity, and an in-house-built extrusion set-up for extrudability analysis. Rheological data suggested an optimal printing temperature of 39 ℃, while extrudability tests indicated 43 ℃, which the differences in viscosity can explain. Texture analysis revealed varying extrusion forces across nozzle sizes (25G, 27G, 30G). The rheological and texture data correlation underscores the protocol's utility in adjusting printing parameters. This integrated approach streamlines EB-3DP optimization, particularly in temperature and pressure adjustment and nozzle selection.