Whitepaper · Formlabs SLS powders
Formlabs and AMT: surface quality of SLS parts with vapor smoothing
Selective laser sintering (SLS) makes intricate, robust parts, but their surfaces come out rough and porous. This collaborative study by Formlabs and AMT applies AMT vapor smoothing to Formlabs SLS powders to bring the surface closer to injection molding.

- With
- Formlabs
- Material
- Formlabs SLS powders
- Printing
- Formlabs SLS
- Published
Source:Formlabs whitepaper, amtechnologies.comPDF (opens in a new tab) published
How vapor smoothing works
The part’s surface is exposed to solvent vapor, which melts the surface layers for a smoother finish while preserving the core structure. The process is highly controlled, so the finish can be tailored.
Advantages
- Surface quality: up to 81% reduction in surface roughness, with a consistent, semi-glossy finish
- Durability: better resistance to moisture and bacteria, useful in harsh environments and medical applications
- Uniform application: the vapor reaches all surfaces, so complex geometries get a consistent finishPDF
Mechanical integrity
Vapor smoothing has minimal impact on mechanical properties, preserving or slightly improving tensile strength and elongation at break.PDF
Process considerations
Part geometry, racking and avoiding solvent pooling all matter. Predefined profiles for specific SLS materials and part designs help reach the desired result.
Applications and options
Vapor smoothing is used in automotive, medical and consumer products, on parts such as air intake manifolds, medical devices and electronic accessories. The study includes 3D Nation, an automotive and aerospace prototyping company that reaches injection-molded part quality without traditional tooling in prototyping. Options range from in-house equipment to service partners, depending on part size, complexity and volume.
Test your parts
Send us a part. See it smoothed.
We vapor smooth your own parts and send them back with the results. No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks1


