Laser Sintering at Protogenic

Download PDF Protogenic has an EOS P385 Laser-Sintering system, which enables you to receive direct manufactured nylon parts, directly from your CAD files.  For more information, please read through this page, and let us know if you still have any questions.  And if you have a part you'd like sintered, we're always happy to quote it for you.

LS, or Laser Sintering, defined: Laser Sintering is a process that uses a laser beam to selectively melt a heated powder.  It's done layer by layer, in usually .006'' (.150mm) layers.  The process is analogous to Stereolithography, but instead of a vat of resin, there is an exchangeable frame filled with Nylon powder, yet in both processes the material is solidified using a laser beam.  To learn more about the process, or find out more about EOS, click here: http://www.eos.info/home.html?L=1.

Is it the same as SLS? SLS, or Selective Laser Sintering, is actually a registered trademark of 3D Systems, and their proprietary process.  So while similar, the two processes are in fact a little different, the machine we have is made by EOS.

What kind of material is it? The material is white, called Fine Polyamide PrimePart, aka Nylon 12.  You can download the material specifications, as well as most of the information on this page here, and you can download all of Protogenic's material specs here.  

What's better, sintered parts or Stereolithography parts? The short answer is ''it depends.''  Sintered parts will be considerably more durable, and they'll also maintain their material properties long after they're built.  Stereolithography parts, or SLA's, will absorb moisture over time, which causes them to expand and become more brittle.  SLA's are more dimensionally accurate, and they are the best prototypes for high quality cosmetics, making them excellent candidates for RTV mold master patterns.  SLA's can also be polished clear.  Sintered parts will have a rougher surface finish than SLA's, but the mechanical properties make them excellent candidates for direct manufacturing.

So what is Direct Manufacturing? Direct manufacturing is the term used to describe an evolution in manufacturing practices, in which the use of hard tooling is completely abandoned.  The engineer forgets about design for manufacturing, parting lines, draft angles, etc., and instead uses the direct output of a rapid prototyping process as actual production parts.  Sintered parts are ideal for this, since the parts are made from actual Nylon.  There's also a time and cost savings associated with direct manufacturing, since the process of injection molding and tooling is eliminated altogether.  Another benefit is the design of the part can remain somewhat flexible, since there is no tooling to modify, a new revision is as easy as changing the CAD file.  Ideal applications for direct manufacturing are complex geometries, fairly low volume, or non-cosmetic parts, where absolute dimensional accuracy isn't critical to function.  Examples include cable routing, wiring harnesses, internal chassis, clips, and connectors, to name a few.  You can see more examples of direct manufactured plastic parts at http://www.eos.info/applications/target-plastic-parts/directpart-examples.html?L=1.

What kind of accuracy can I expect from LS? Sintering is not as accurate as Stereolithography, that's a given.  The beam diameter in the sintering machine is about .026'', almost twice the diameter as what's in our SLA machines.  Our techs are continually working towards improving accuracy, a process that will continue and remain at the forefront of every build setup (the same holds true for SLA's, by the way).  That said, in the X and Y axis expect your parts to be +/- .005'' for all features less than 2", and +/- .003"  per inch for all features larger than 2".  For Z, expect your parts to be within .010'' of nominal in the first inch of Z, with +/- .003''/inch, for each inch thereafter.  Holes typically build .010" under nominal, but can be post-drilled as specified by you.  For larger quantity orders where multiple runs are involved, we can make adjustments to subsequent runs based on the dimensional feedback of prior runs, to improve dimensional accuracy over time.

Can I paint my sintered parts? Yes you can.  But know that most paints won't stick to Nylon very well, so the paint could rub off even with normal handling.  Also, the sintered parts you receive won't have any finishing done to them, so if you're looking for a show-quality prototype for your photo shoot or trade show booth, a better solution is a set of SLA's with a paint ready finish, or urethane castings.  But you're welcome to color your sintered parts, and you can even dye them different colors using fabric dye.