Characterization of 3D printed long fibre reinforced composites

Additive Layer Manufacturing (ALM) process is used in the present investigation to manufacture long fibre reinforced composite parts using the MarkOne® 3D-printer. In ALM, a continuous filament (including a tow of fibres) of composite material is injected by the printer, at high temperature, over a plain tool, forming the part while the material is cooled down. The used composite filament is formed by a PA (Nylon™) matrix and carbon or glass fibre reinforcements. Previous works have shown an improvement on the mechanical properties of a part, when some zones include a nylon based composite reinforcement using ALM. Nevertheless, the characterization of fully made nylon-based ALM composite material parts has not been reported. Thus, the aim of this investigation is the experimental characterization of composite nylon-based coupons. The plane strength and stiffness properties of the composites are obtained, both for tensile and compression load states. Results showed that the obtained mechanical properties for ALM composites are not yet comparable to those obtained by traditional methods (pre-pregs). This fact may be explained by the high porosity found in ALM coupons as well as a low fibre volume obtained. Nevertheless, the mechanical properties improvement in comparison to non-reinforced nylon parts is remarkable.