R_Bibb_Medical_Modelling_The_Application_of_Adv.pdf

Physical reproduction 77
5.12 Selectively coloured model showing a tumour (see also colour
section).
Perfactory ® machine. Models are built using liquid resin which is cured to
solid using visible light. In their Perfactory ® machine, models are built onto
a platform that rises by a layer thickness after each layer is produced.
Raising the build platform allows the liquid to fl ood into the gap between
the transparent base of the vat and the model. The fl at, transparent base
means that layers are created at the exact layer thickness and are perfectly
fl at and level. Creating this fi xed gap eliminates any of the settling or levelling
procedures required in SL, which in turn accelerates the process. This
process also means that the layer thickness can be reduced, leading to
models built from very thin layers, which improves surface fi nish. A larger
Vanquish machine is also available but builds in the conventional downwards
direction.
As the cross section is projected from below in one instant, the exposure
time for each layer is fi xed regardless of the geometry of any given cross
section. This provides rapid and predictable build rates. This method also