SLS 3D printing: tough nylon parts, no supports
Selective laser sintering (SLS) fuses fine nylon powder with a laser, layer by layer. The loose powder around each part supports it as it is built, so complex and interlocking shapes need no support structures, and the nylon is tough enough for functional testing and end-use parts.
- Nylon PA12tough and durable
- Nosupport structures
- Functionalprototypes and end-use parts
How SLS builds a part
The diagram above shows the machine in section view. Here is what happens, step by step.
- 1
Spread powder
A roller spreads a thin layer of nylon powder across the build area, inside a chamber heated to just below the powder's melting point.
- 2
Laser fuses a layer
A laser traces the part's cross-section, raising the powder just enough to fuse the particles together.
- 3
Lower and repeat
The build piston lowers by one layer and fresh powder is spread. The unfused powder stays in place and supports the part.
- 4
Cool and finish
The build cools slowly, then parts are removed from the powder, cleaned and bead blasted, and dyed or painted if required.
Strengths and limitations
Every process has trade-offs. Knowing them up front saves time and money.
Strengths
- Fully functional prototypes with good mechanical and thermal resistance
- Tough enough for snap fits and living hinges
- No support structures, so very complex geometry, internal channels and nested parts are possible
- Glass-filled nylon adds stiffness for demanding functional parts
- Economical for batches: many parts can share one build
Limitations
- Slightly rough, grainy and porous surface, not as smooth as SLA. Parts can be primed and finished smooth.
- Shrinkage can cause warping, bowing or curling, depending on part geometry
- Feature detail is not as crisp and sharp as SLA
- Properties vary a little with build position and direction
What your parts are made of
Nylon PA12 is the standard SLS material. Glass-filled nylon is available for parts that need extra stiffness. Full details and sourced data are in our material overview.
Typical uses
SLS is one part of a complete prototyping and manufacturing service. Many projects combine several processes.
- Functional prototypes for real-world testing
- Snap fits, clips, hinges and ducts
- Complex housings and internal channels
- Low-volume end-use parts without tooling
- Automotive, aerospace and engineering components
- Jigs, fixtures and assembly aids
Need production material properties? SLS nylon is tough, but if a part must match a specific engineering plastic, CNC machining cuts it from the real material. For a batch of production-look parts, see vacuum casting.
Compare processesCommon questions
Still unsure? Contact us or call +61 3 9764 2749.
What material is used for SLS 3D printing?
Nylon 12 (PA12) is the standard SLS material: tough, with good heat resistance for a printed plastic. Glass-filled nylon is available for extra stiffness.
Does SLS need support structures?
No. The unfused powder around the part supports it during the build, so overhangs, internal channels and even pre-assembled moving parts can be printed.
How smooth are SLS parts?
As printed, SLS parts have a slightly grainy, matt surface. They can be bead blasted, primed and painted for a smoother finish.
Is SLS the same as sintering?
The name says sintering, but in nylon SLS the laser actually heats the powder just enough to fuse the particles. The rest of the bed is held just below the melting point.
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