3D Systems sPro, User Manual

Page: 44 / 280

SLS p r o c e s s 4 4 S L S P R O C E S S
u s e r ’ s g u i d e w h a t i s t h e “ S L S p r o c e s s ” ?
W h at i s t h e “ S L S Pr o ce s s” ?
“SLS” stands for “Selective Laser Sintering”; an
additive rapid manufacturing technique that
uses a high power CO2 laser to fuse DuraForm
plastic powder into a mass representing a
3-dimensional object, or “part.”
The laser selectively fuses powder by scanning
cross-sections generated from a “sliced” 3-D
digital description of the part (e.g. an STL file
created from a CAD file) on the on a smooth bed
of powder. Typically, the taller a part is, the more
cross section layers it has. The number of layers
can run into the thousands.
After the laser scans each cross-section, the
powder bed lowers by one layer thickness, a new
layer of material is applied on top, and the
process repeats until the part is done.
Compared to other rapid manufacturing
methods, SLS can produce parts from a relatively
wide range of commercially available powder
materials, including polymers (nylon, also glass-
filled or with other fillers, and polystyrene),
metals (steel, titanium, alloy mixtures and
composites) and foundry sand. The physical
process can be full melting, partial melting, or
liquid-phase sintering. And, depending on the
material, up to 100% density can be achieved
with material properties comparable to those
from conventional manufacturing methods. In
many cases large numbers of parts can be packed
within the powder bed, allowing very high
productivity.
SLS is performed by machines called SLS systems;
the most widely known model of which is the
sPro
® SLS system. SLS technology is in wide use
around the world due to its ability to easily make
very complex geometries directly from digital
CAD data. While it began as a way to build
prototype parts early in the design cycle, it is
increasingly being used in limited run
manufacturing to produce end-use parts.