The standard data interface between CAD software and the machines
is the STL file format. An STL file approximates the shape of
a part or assembly using triangular facets. Tiny facets produce
a higher quality surface.
The word "rapid" is relative: construction
of a model with contemporary methods can take from several hours
to several days, depending on the method used and the size and
complexity of the model. Additive systems for rapid prototyping
can typically produce models in a few hours, although it can vary
widely depending on the type of machine being used and the size
and number of models being produced simultaneously.
Some solid freeform fabrication techniques use two
materials in the course of constructing parts. The first material
is the part material and the second is the support material (to
support overhanging features during construction). The support
material is later removed by heat or dissolved away with a solvent
or water.
Traditional injection molding can be less expensive
for manufacturing plastic products in high quantities, but additive
fabrication can be faster and less expensive when producing relatively
small quantities of parts.
A large number of competing technologies are available
in the marketplace. As all are additive technologies, their main
differences are found in the way layers are built to create parts.
Some are melting or softening material to produce the layers (SLS,
FDM) where others are laying liquid materials thermosets that
are cured with different technologies (SLA, MJM, PolyJet). In
the case of lamination systems, thin layers are cut to shape and
joined together.
Much of the information on this page was sourced
from Wikipedia.org
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