The powder packing for each CaP:CaSO 4 composite powder was de-
termined by measuring the in-process powder bed density and bulk
density.Twocustom-madereservoirs(150mm×150mm,withadjust-
able height) were placed in the feed and build area in a thermal ink-jet
3Dprinter(Zcorp310,ZCorporation,UK).Thereservoirsweredesigned
for the purpose of reducing the amount of powder required for the 3DP
process and also to assist in the measurement of the powder bed densi-
ty.Specifically,thereservoirin thefeedareawasfilledwitha composite
powder prior to the 3DP process. During the process, a relative small
component (0.1 mm × 0.1 mm × 10 mm) was printed, which added
negligible mass to the powder bed. Consequently the powder was
spread from the feed area to the other reservoir located in the build
area. Following this step, the reservoir in the build area was removed
fromthe3Dprinter.Themassofpowderwithinthereservoirandheight
of thepowder bed were measured and subsequently used to determine
thein-process powder bed density. Thepowderbulk density was quan-
tified in accordance with the ISO Standard 10545–3 [33]. Additionally
the powder bed packing ratio was calculated (Eq. (1)).