  The feasibility to manufacture scaffolds of poly-lactic acid reinforced with
Zn particles by fused filament fabrication is demonstrated for the first time.
Filaments of 2.85 mm in diameter of PLA reinforced with different weight
fractions of $\mu$m-sized Zn - 1 wt. \% Mg alloy particles (in the range 3.5 to
17.5 wt. \%) were manufactured by a double extrusion in method in which
standard extrusion is followed by a precision extrusion in a filament-maker
machine. Filaments with constant diameter, negligible porosity and a
homogeneous reinforcement distribution were obtained for Zn weight fractions of
up to 10.5\%. It was found that the presence of Zn particles led to limited
changes in the physico-chemical properties of the PLA that did not affect the
window temperature for 3D printing nor the melt flow index. Thus, porous
scaffolds could be manufactured by fused filament fabrication at 190\textdegree
C with poly-lactic acid/Zn composites containing 3.5 and 7 wt. \% of Zn and at
170\textdegree C when the Zn content was 10.5 wt. \% with excellent dimensional
accuracy and mechanical properties.
