Robot Mechanisms and Mechanical Devices Illustrated - Profe Saul

Introduction
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water-soluble supports are formed by a separate extrusion head, and they
can be washed away after the model is complete.
Three-Dimensional Printing (3DP)
The Three-Dimensional Printing (3DP) or inkjet printing process, diagrammed
in Figure 6, is similar to Selective Laser Sintering (SLS)
except that a multichannel inkjet head and liquid adhesive supply
replaces the laser. The powder supply cylinder is filled with starch and
cellulose powder, which is delivered to the work platform by elevating a
delivery piston. A roller rolls a single layer of powder from the powder
cylinder to the upper surface of a piston within a build cylinder. A multichannel
inkjet head sprays a water-based liquid adhesive onto the surface
of the powder to bond it in the shape of a horizontal layer of the model.
In successive steps, the build piston is lowered a distance equal to the
thickness of one layer while the powder delivery piston pushes up fresh
powder, which the roller spreads over the previous layer on the build pis-
Figure 6 Three-Dimensional Printing (3DP): Plastic powder from a reservoir is spread
across a work surface by roller onto a piston of the build cylinder recessed below a table
to a depth equal to one layer thickness in the 3DP process. Liquid adhesive is then
sprayed on the powder to form the contours of the layer. The piston is lowered again,
another layer of powder is applied, and more adhesive is sprayed, bonding that layer to
the previous one. This procedure is repeated until the 3D model is complete. It is then
removed and finished.