Feasibility analysis and characterization of an extrusion-based AM process for a two-component and biocompatible silicone

Silicone is a very widespread material with important applications especially in the medical field. Currently, Additive Manufacturing (AM) is a promising technology for the fabrication of custom products and some commercial machines are available on the market for processing biocompatible silicone. Although, no scientific literature is available on the characterization and control of the process. Given the research challenge, this work presents and investigate a novel process for 3D printing of biomedical silicone. An ad hoc equipment was realized and integrated with the Fab@Home 3D printer in order to thermally control the extrusion process of the silicone. Then, the equipment was characterized and used to study the feasibility of the process and the influence of the process parameters (Deposition Rate, Path Speed, Temperature). Quality control charts and Design of Experiments methods were used to study the stability of the process and to statistically evaluate the influence of the process parameters. Results brought to the definition of a process feasibility window and to a numerical model able to predict the dimension of the printed layer as a function of the tested parameters. A technique for the AM of biomedical silicone parts was developed and characterized. In particular, results furnish a fundamental knowledge for the control of the process. The biomedical field is one of the main target, particularly the fabrication of custom medical devices.