Feasible Regions of Nozzle Temperature, Extrusion Pressure, and Printing Speed in Extrusion-Based Printing Using a Sodium Alginate–Carboxymethylcellulose–Collagen I Bioink

This study determines the feasible regions of nozzle temperature, extrusion pressure, and printing speed in extrusion-based printing using an acellular sodium alginate-carboxymethylcellulose-collagen I bioink. The tested range of nozzle temperature was from 10 to 35 °C in 5 °C increments, the range of printing speed was from 5 to 20 mm/s in 5 mm/s increments, and the range of extrusion pressure was from 10 to 100 kPa in 10 kPa increments. The feasible regions were defined as the combinations of process parameters that produced continuous extruded lines. Results show that continuous extruded lines were achieved at higher extrusion pressures (70-100 kPa) across most tested printing speeds and nozzle temperatures. In contrast, an extrusion pressure of 10 kPa resulted in discontinuous extruded lines under all tested combinations of nozzle temperature and printing speed, and an extrusion pressure of 20 kPa led to discontinuous extruded lines under all tested printing speeds and all tested temperatures except for 35 °C. Intermediate extrusion pressures required lower printing speeds to produce continuous extruded lines. These results highlight the interaction effects of extrusion pressure and printing speed on maintaining continuous extruded lines across the tested nozzle temperatures. These findings provide practical guidance for selecting extrusion pressures and printing speeds across different nozzle temperatures for printing of a sodium alginate-carboxymethylcellulose-collagen I bioink.