Investigation of process variables in 3D printing of chocolate

Combined additive manufacturing (AM) and syringe deposition as a process method for complex parts manufacturing, attracted the attention of many industry and research communities due to its ability to shorten design to production cycle. In this method, various materials such as polymers, food pastes, etc. are deposited in layers by a CNC controlled syringe, gradually outlining the shape of the part.

The aim of this research was shaping chocolate parts by AM technology. For this purpose, a commercial 3D printer equipped with a specially designed syringe head with temperature control was used.

DSC test indicated that the proper temperature for tempering of the chocolate is between 32 and 40 oC. The rheology test indicated that by increasing the temperature, the chocolate viscosity was decreased and leaded to more flow rate of the extruded chocolate and thus reduced the shape resolution. On the other hand, the process parameters such as the nozzle height from the printing plate, the nozzle diameter, the software input diameter setting and the temperature of the build plate also affect the print resolution. So, different input diameters were examined at various temperatures and optimum conditions for the best printed part resolution were obtained as follow: nozzle temperature of 32 oC, printing height equal to nozzle diameter, software input diameters of 1.98 mm and plate temperature of less than 10 oC Based on the optimum condition, complex shape of chocolate object were 3D printed.