Novel Technique Based on Fused Filament Fabrication (FFF) and Robocasting to Create Composite Medical Parts

Abstract

The purpose for this study is to obtain a new composite manufacturing system based on Additive Manufacturing techniques that allows the creation of parts for the medical industry. These pieces will be resistant, lightweight and may have geometries more complex than those created with traditional systems of composite material. The new system is based on the union of two heads on a 3D Rep-Rap printer. One of the heads is an extruder head of thermoplastic Fused Filament Fabrication (FFF) and the other is a dosing head, based on the Robocasting technique, designed to be assembled on the 3D printer. Thermoplastics material and epoxy resin will be used. The alternate printing of both materials generates a piece of composite material. This new technique will allow to increase the structural properties of the piece in the XY plane. The new additive manufacturing system allows to obtain mechanical improvements both in the modulus of elasticity and in the tensile strength. Increase the modulus of elasticity of a value between 50 and 80% depending on the thermoplastic filament used. In the same way the tensile strength has increased between 50 and 60%. The improvement in the strength / weight ratio allows to this new additive manufacturing system to create medical pieces in which the lightness and resistance are its main characteristic, such as orthopedic prostheses.The results show that the use of FFF together with Robocasting, as a manufacturing process for end-use parts, generates an additional advantage that had not been considered until now. The combination of a thermoplastic and an epoxy resin opens a new path in the additive manufacturing since it allows creating pieces with new qualities without being conditioned by the design.

Keywords: Composite; FFF; Medical parts; Robocasting.