This study evaluated the 3D printabilityof different CaP:CaSO 4 pow-
der combinations with the use of water-based binder. In order to assist
in the selection of an appropriate powder formulation, methods have
been developed to quantify 3DP relevant variables, e.g. in-process pow-
der bed packing, binder drop penetration behavior, powder-binder
wettability and the quality of the 3DP final component. The influence
of CaP powder particle size, CaP:CaSO 4 ratio and type of CaP on the 3D
printability was demonstrated. In particular, this study confirmed the
importance of particle size to the successful application of the 3DP pro-
cess. A loosely packed powder bed showing a high level of heterogene-
ity was formed using fine powders (≤20 μm), which resulted in slow
drop penetration speed, large drop penetration depth, low wetting
ratio,poor green mass and green strength for the final 3DP components.
The addition of β-TCP may compromise the CaSO 4 -water reactivity, as
β-TCP:CaSO 4 powder combinations had significantly lower wetting
ratio and green strength when compared to the HA:CaSO 4 powdercom-
binations. Promising results can be obtained using the CaP:CaSO 4 pow-
dercombinationswithCaPparticlesizerangingfrom30to110μm,CaP:
CaSO 4 ratio (25:75 wt.%) and type of CaP (HA). This study has devel-
oped CaP:CaSO 4 powder combinations that are highly applicable to
the thermal ink-jet 3DP process for the manufacture of TE constructs
for non-load bearing orthopedic applications.