3D printing is used across many industries,
from engineering to manufacturing,
dental, healthcare, jewelry, and more.
The technology offers a wide range of applications,
from visual and functional prototypes to end-use parts.
There are many 3D printing solutions on the market.
Each one has its own benefits and limitations
that make it more suitable
for certain applications than others.
To help you identify the solution
that best matches your requirements,
we'll be comparing functional and visual characteristics
of three of the most common
3D printing technologies for plastics:
FDM, SLA, and SLS.
Choosing the technology and material
with the right functional properties
is crucial to make sure
that your parts will work as designed,
starting with build dimensions.
Most common FDM printers offer
around 200-millimeter-cubed-size build volume
with large-format options going as big
as 300-by-300-by-600-millimeter size.
Like with FDM, professional desktop SLA printers
can come in standard or large-format models,
with most standard sizes being
around 200 millimeter cubed size
and large-format models offering
a five to 10 times bigger build volume.
The build volume of benchtop SLS printers
is comparable to standard FDM and SLA printers.
The next thing to consider
when it comes to functional properties is tolerances.
If your parts require tighter tolerances
and higher accuracy,
SLA and SLS are your best options.
Both technologies use highly precise lasers
to form each layer with reliable and repeatable results.
Moving on to material properties,
FDM and SLA both offer a wide range of materials
with properties comparable
to common injection-molded plastics.
Material selection for SLS is more limited,
but this technology is the best choice
for durable end-use parts.
SLS nylon parts also have great heat
and chemical resistance.
FDM 3D printers use thermoplastic filaments,
such as ABS, PLA, and various blends.
SLA printers create plastic parts
from a variety of thermoset resins,
each formulated to match the characteristics
of common plastics.
SLA 3D printers offer the most flexibility, literally,
with both flexible and soft, silicone-like materials.
SLA also offers the material
with the highest heat deflection temperature,
238 degrees Celsius.
SLA printers provide the widest selection
of biocompatible materials
for dental and medical applications as well.
The most common material for SLS 3D printers is nylon,
a highly capable engineering thermoplastic.
Desktop plastic 3D printers can also be used
to create metal parts by casting 3D-printed patterns.
SLA is a go-to technology for 3D-printed castable patterns
for jewelry, dentistry, and engineering applications,
while FDM also offers some more experimental options.
In case you have specific requirements
in terms of strength, stiffness, elongation,
durability, or other properties,
we recommend looking at technical data sheets.
For applications like concept, artistic, or sales models
and looks-like prototypes,
you should select a technology based on appearance
and visual characteristics.
In FDM 3D printing, coarse layers are extruded by a nozzle,
which lacks the control and ability
to achieve the level of details
that the other two technologies can offer.
That's why FDM prints tend to have clearly visible layers.
Thanks to the highly precise lasers,
SLA and SLS are the gold standard
for producing high-quality parts and models
with intricate details and fine features.
In SLA, the laser controls the light with high precision,
and each layer takes a parabolic cylinder shape
that aligns better with the previous layer.
This creates a smoother surface finish
right out of the printer with reduced staircase effects,
especially for overhanging and upright geometries.
SLA is the gold standard for producing high-quality parts
and models with intricate details and fine features.
SLS printers also use lasers
to achieve highly detailed printed parts,
but because lasers work by centering a powdered material,
parts come out of the printer
with a slightly rough, grainy surface.
(soft music)
3D-printed parts can also be sanded, polished,
primed, and painted to achieve the desired finish.
Post-processing SLS parts is the easiest
because there are no printed supports
to remove from the printed parts.
SLA parts require some sanding to remove support marks
when printed on supports,
while FDM parts need
substantially more sanding and polishing
before priming and painting for a high-quality finish.
FDM materials are available in a wide variety of colors,
while some SLA resins can be mixed with color pigments
to match almost any custom color.
Lastly, SLA has the unique capability
to create transparent or even optically clear parts.
SLS parts can be dyed to achieve different colors.
FDM, SLA, and SLS 3D printing
offer many materials and options
to best match the functional and visual requirements
of your application.
In many cases, it can easily happen that two
or even all three of the technologies are a good fit,
in which case it's your call to prioritize your requirements
and weigh other considerations, like speed, cost,
workflow, or ease of use.